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ThermArk

A Low Cost Thermal Insulation for Humanitarian and Disaster Relief Services

MSE 4410-A1

Instructor: Dr. Sundaresan Jayaraman

Group: Kinsey Canova, Erin Flynn, Jarad Heimer, Tyler Rice

Georgia Institute of Technology

North Avenue NW, Atlanta, Ga 30332

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Table of Contents Executive Summary .................................................................................................................................... 3

Introduction ................................................................................................................................................ 4

Background ............................................................................................................................................. 4

Mission Statement................................................................................................................................... 4

Concept Generation .................................................................................................................................... 5

User Needs .............................................................................................................................................. 5

Supergroups (ITYs) ................................................................................................................................ 6

Prioritization Matrix ............................................................................................................................... 8

Needs-Metrics Matrix ............................................................................................................................. 9

Initial Concepts ..................................................................................................................................... 10

Structure............................................................................................................................................ 10

Insulation .......................................................................................................................................... 14

Closing Mechanisms ......................................................................................................................... 15

Concept Screening and Selection .......................................................................................................... 15

Detailed Design/Concept Architecture ...................................................................................................... 16

Material Selection ................................................................................................................................. 16

Final Product Description ..................................................................................................................... 17

Manufacturing Process.......................................................................................................................... 18

Sustainability Assessment ..................................................................................................................... 20

Feasibility Assessment .......................................................................................................................... 20

References ................................................................................................................................................ 21

Appendix .................................................................................................................................................. 25

Appendix A: Prioritization Matrices ..................................................................................................... 25

Appendix B: Concept Selection Matrices ............................................................................................. 26

Appendix C: Detailed Design and Project Architecture ........................................................................ 26

Appendix C1: Material Selection ...................................................................................................... 26

Appendix C2: ID Charts ................................................................................................................... 30

Appendix C3: Sustainability ............................................................................................................. 31

Appendix C4: Final Ideal and Marginally Acceptable Metrics ......................................................... 31

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Executive Summary In the city of Atlanta, Georgia, emergency shelters provide safe and warm sleeping

environments for approximately 3,280 of those less fortunate in times of life-threatening

environmental conditions [1]. Unfortunately, as of 2015, the total homeless population of Atlanta

(the sum of those in living emergency shelters and those living on the street) was approximated at

4,317 people, leaving 1,037 men, women, and children truly homeless living on the street [1]. With

December rapidly approaching, the grips of winter will set in and put those 1,037 homeless

individuals in cold weather-induced, life-threatening environments every night and day. Similarly,

those affected by disaster in the winter months require similar protection due to loss of artificial

heat production or shelter.

The current methods of protecting these individuals rely on the donations or purchase of

protective clothing and blankets to charity or government-funded programs as “Church on the

Street” or FEMA respectively. Specifically for the homeless, layers of clothes and blankets do not

provide adequate protection from wind, rain, other wintery precipitation. These conditions lead to

wet clothing and blankets, inducing 20x more body heat loss than the dry alternative [2]. This

increases the potential of hypothermia and other cold-weather afflictions such as frostbite. To limit

this concern, the product must be waterproof and windproof. The product must also be thermally

insulating, transportable, durable, gouge-resistant, easy to clean, and cost-effective. The cost-

efficiency is required so humanitarian and disaster relief agencies can afford to purchase and

rapidly distribute the product at critical times. Cost is the current limitation, since consumer

products, such as the Bivy, fulfill all of these needs but costs between $40 and $500 per unit. On

the cost-effective side, foil blankets or foil sleeping bags keep the user warm and isolated from the

harsh environment for under $3 a unit but lack durability due to tearing [3].

The primary market for this product is relatively large in the United States with an average

of 3.5 million American being temporarily or permanently homeless on any given night due to

disaster or permanent homelessness [4]. Though the lucrative nature of the primary market is

limited due to a combination of charitable use and subsequent low required manufacturing and

distribution costs, profitability is possible due to the market size and the sales into such secondary

markets as camping equipment, which, is projected to be a $5 billion market by 2019 [5].

The user needs and market research led to the development of a final product concept of

ThermArk, which combines all of the positives from the current products such as the Bivy or the

common donated blanket but without the high cost or lack of protection from wet and windy

conditions. This is achieved through a robust, multilayered low density polyethylene (LDPE)

covering containing button snaps to seal the user from the harsh external environment. Flexible

LDPE foam provides thermal insulation and padding while external and internal thermally-adhered

sheets of LDPE provide abrasion resistance and heat reflectance via vapor-deposited aluminum on

the internal LDPE sheet. The use of one material, LDPE, reduces costs and limits environmental

impacts due to the ease of ability to recycle and/or downcycle components at end of life. With the

help of ThermArk, the homeless and those stricken by disaster can sleep soundly, knowing they

will stay protected from the harsh winter environment in their moment of need.

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Introduction

Background

On January 28, 2014, “Snowpocalypse” descended on the city of Atlanta [1]. There was a

general hysteria as people rushed to the warmth and comforts of home to ride out the

storm. However, some people had no home to go to. On any given night in the state of Georgia,

approximately 6,000 individuals sleep unsheltered [2]. There are not enough shelter beds to go

around, and not everyone is eligible for temporary housing. Therefore, hunkering down and

fighting the elements is the only option available. However, surviving exposure to

prolonged subfreezing temperatures, severe wind chill, and several inches of snow is difficult

even for those trained in survival. For those with limited supplies and no formal survival training,

it is nearly impossible. Hypothermia deaths among the homeless are common in the winter; 700

people die annually in the US from hypothermia simply because they are homeless [3]. It does

not need to be snowing, windy, or subfreezing for hypothermia to set-in; hypothermia cases have

been reported at temperatures as high as 50°F [3]. Homelessness in a developed country like the

United States should not be a death sentence.

The current methods of warmth available to the homeless include emergency winter

shelters, traditional blankets, and makeshift shelters. The best of these are the winter shelters

which open when temperatures drop below freezing. The shelters protect the homeless from the

severe elements of wind and precipitation; however, these shelters have many drawbacks

that stop them from being effective at preventing hypothermia deaths. The primary shortcoming

is the lack of space; each shelter has finite space and once these spaces are filled, anyone else is

turned away. Additionally, the shelters are usually just a large stone room filled with

many people; they are often loud, drafty, and not necessarily heated. For those unable to get into

a shelter, blankets and makeshift protections are often the only alternative. Blankets,

although readily available, are bulky and permeable by water and wind. Any make-shift

protections are often only effective at partially blocking wind and precipitation. The insulation

provided by blankets or a partial-shelter is often not enough to protect the person when

temperatures stay below freezing for an extended period of time.

Technologies exist to protect people from harsh elements and cold, but many of these

are expensive and not readily available for those experiencing homelessness. A Bivy is a hybrid

of a sleeping bag and a tent that boasts full body insulation capabilities. However, even a

cheap Bivy usually costs $60, which is far too expensive for a homeless person. Insulating

emergency shelters used by disaster relief agencies like the Red Cross are also expensive as well

as too bulky and flashy to be used by those experiencing homelessness. There is a need for an

insulating shelter to be available to homeless people during harsh weather and the goal of this

project is to fulfill that niche.

Mission Statement

Initial development of the mission statement focused on helping add insulation to

makeshift shelters the homeless may already have, such as cardboard boxes, tarps, or overpasses.

Initially proposed product benefits suggested the product “would use adhesive on the back of

the insulator to be able to stick to whatever structure is being used to provide shelter.” However,

research found that this solution may not be practical for many of the homeless population. The

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homeless frequently move around, which would require removing the adhesive insulation from

one structure and adherence to another structure over multiple iterations. Additionally, homeless

do not always have a makeshift shelter, so the benefits of an adhesive would not be realized. After

learning these realities, the mission statement evolved to focus on developing a standalone product

that would protect the user from the elements and the cold temperatures.

The product developed is aimed primarily at helping the homeless. The idea is that the

product would have low enough cost that charities and aid groups would be able to purchase it in

bulk and distribute it among the homeless. However, the functionality of the product could also

be used in emergency situations, such as by those stranded in blizzards or displaced by floods.

Thus, this product could be a component of emergency kits or distributed by disaster relief

agencies. The design process focused on the needs of the homeless due to their need for such

protection being more eminent and extending for a longer period of time. The final mission

statement guiding product design is shown in Figure 1.

Figure 1: Product mission statement

Concept Generation

User Needs

Due to the nature of the project, conducting interviews of the primary users was infeasible.

Instead, interviews of those who interact with the homeless on a regular basis was done. These

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three were Pastor Andy Odle, who works for Church on the Street, and Marc Smith and Paige

Hoerle, who both work for Christian Campus Fellowship at Georgia Tech. Both of these

organizations do outreach programs to assist the homeless, and interview with them revealed that

the mission statement suggesting adhesive for a structure needed to be changed to fit the new user

needs. The final user needs can be found in Table 1. This process taught that it is important to

survey user needs before developing a mission statement, especially when the primary market is

unknown.

Table 1. User Needs

Needs

Thermally insulating et. al. Breathable

No risk of suffocation Meets restrictions set by locality

Thermal protection against ground Locking mechanism

Waterproof Simple packing

Windbreaker/Wind-proof/resistant Lightweight

Low-cost Packable to fit in small volume

Endures one month of use Convenient to carry

Can be cleaned May be carried in mass transit systems

Retains functionality when abraded etc. Survives opening and closing

Gouge resistant Breathable

Discreet Spatially efficient

Able to see surroundings from inside Expandable

Antimicrobial Comfortable

Along with gathering user needs, interviews allowed for clear identification of the lead

customers and what issues they would encounter. It was learned that there are three types of ways

to sleep when you are homeless: in a shelter; unsheltered on the streets or in the park, also known

as rough sleepers; and tent cities, typically outside of the city away from public spaces where many

people can set up camp. The product’s main goal is to help all these types of sleepers by making

it easily portable, lightweight, low cost, resistant to the cold and other extreme temperatures, water

resistant, easily cleanable, and discreet.

Supergroups (ITYs)

Once user needs were gathered, they were organized into supergroups (ITYs), in order to

simplify future prioritization of the needs. The user needs were grouped into seven ITYs which

were functionality, affordability, durability, portability, safety, reliability, and usability. ITYs were

individually defined to ensure consistency when assigning user needs to those groups. The ITY’s

and user needs are shown in Figure 2.

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Figure 2: ITY's and User Need Assignments

Functionality was defined as the product allows the user to endure and survive the cold

seasons and subsequent associated environments. This ITY was populated with user needs that

were are necessary to keep the user warm and separated from harsh environmental impacts. These

needs are interdependent and require each need to be fulfilled for the product to efficiently

function. For example, if the product was not windproof then it would have ideal thermal insulating

capabilities due to the penetration from the wind and subsequent conductive cooling. These user

needs parallel the mission statement to clearly identify that, if the final product does not fulfill the

needs within the functionality ITY, the product does not align with the mission statement and

requires revision.

A second key point in the mission statement was to create a product that was affordable to

humanitarian and disaster relief organizations; this led to creation of the affordability ITY.

Affordability was defined as “the product can be produced and distributed for minimal cost to the

user.” The only user need that is associated with affordability is cost. Cost includes the sum of the

raw material, manufacturing, distribution, and wholesale expenses that are passed on to the

consumer. Affordability and the user need of cost is paramount and, if it is not upheld, the product

will not be able to be purchased and distributed to those less fortunate.

Durability was defined as “the product functioning adequately over its lifetime.” This ITY

contains the needs of endure at least a month of use, can be cleaned, functions when abraded, and

gouge resistant. The need to endure at least one month of use defines the minimum length of time

the user expects the product to function. One month of use allows a user in Georgia to survive the

coldest period of the year. With consistent use on the streets, the product may come in contact with

rocks, glass, and other damaging materials that may abrade and permanently damage the product.

This is why the product must consist of a material that resists gouging or, if damaged, provides the

same functionality as before gouging. The last need within this ITY was the requirement that the

product has chemical stability and acceptable resistivity to a wide range of chemicals and solutions.

This allows the product to be cleaned with common household or commercial chemicals.

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Since the user may be constantly on the move, an ITY that encompasses all of the needs

which associate with traveling was created. That ITY, portability, was defined as “the user can

travel as needed while transporting the product.” Interviews indicate that many homeless carry

their sleeping materials in a backpack or bag, which set specifications for user needs. One of the

issues that some homeless have is the fear of sudden and rapid evictions from their sleeping or

camping spot. If the eviction happens, the user must be able to quickly gather their belongings or

face civil penalties. To mitigate that fear, the product must have a simple packing scheme that can

be executed rapidly and efficiently.

Safety was designated as an ITY for all of the user needs that fall under the definition of

“the product introduces no new threats to the user.” Due to local laws and ordinances such as the

Urban Camping Ordinance in Atlanta, the user has to be vigilant of the surrounding and not draw

attention to his or herself. If the user cannot see his or her surroundings or the product draws

attention instead of being discreet, the user has an increased chance of violating the local laws and

ordinances. Due to the potential danger caused by other humans, a locking mechanism may be

desired to increase personal safety. One of the largest safety concerns is the ability of the user to

breathe within the product. If the product gives off chemical odors or does not permit air exchange

with the outside environment, the user could suffocate. Another safety-based need is, if the

surfaces of the product are not antimicrobial, then the user may see increased chance of infection,

uncomfortable odors, and/or untimely degradation of the product.

Reliability was defined as “the product functions effectively when the need for use arises.”

Though reliability and durability seem similar, reliability requires that the product functions as

expected with every use while, durability is retaining functionality over time. The only user need

assigned to reliability was survives opening and closing. This was assigned to reliability since,

without the use of an opening or closing mechanism, the product would not be able to effectively

seal the user from the cold harsh environment.

The final ITY, usability, was defined as “product can be used with comfort and

convenience.” This encompassed the needs which are all predominantly "wants," not

requirements. The need comfort defines how the product material feels to the user, specifically the

cushioning of the sleeping surface, when in use. The need for expandability relates to comfort; an

increase of internal surface area when the product is in use increases the amount of space to move

around. This makes the product feel less restrictive and more comfortable to the user. Breathable,

in this context, considers how comfortable it is to breathe the air when using the product. For

example, a high internal humidity will make sleeping in the product uncomfortable and more

difficult due to the air being more difficult to breathe. If excess design focus is put on comfort and

non-vital parts, the product may quickly increase in cost. Spatial efficiency was chosen to keep the

product affordable to the user/consumer. Spatial efficiency is the lack of excess material or

addition of non-vital survival aspects on the product.

Prioritization Matrix

As the design process continued, a ranking method was used to determine which

supergroups and needs take precedent over others. This was a vital part of the design process since

it defined what needs and supergroups would be higher priority when discussing future trade-offs.

Prioritization matrices were conducted on two levels. The first was based on the ranking of the

individual ITYs against each other and the second was a ranking of the user needs within each

ITY.

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The prioritization matrix for the ITYs, Figure 3, was determined through ranking the

importance of each ITY against each other. The comparison method was conducted on a scale of

0.10, 0.20, 1, 5, and 10. A designation of 1 between two ITYs signified that they are of equal

importance, 5 signified that the ITY in the top row was slightly more important than the ITY in

the side column, and 10 signified that an ITY was significantly more important than the other.

Designations of 0.10 and 0.20 are, respectively, inverses of the designation of 10 and 5. The

prioritization matrix showed that functionality and affordability were determined as equal and

were the highest priority, as expected, followed by durability, safety, portability, reliability, and

usability. The matrix yielded a surprisingly low rating for usability. This rating was the result of

the definition of usability and the input received from the three interviews conducted which, stated

that comfort is not significant factor when concerning life and death situations. A comfortable

product may lead to pushback by charities since their ultimate goal is to transition the homeless

from street or "rough" sleeping to a more permanent housing situation. Comfortability may inhibit

the desire to improve the situation at hand and create a larger homelessness issue. These

prioritizations were later utilized within the other ranking matrices such as the concept and material

decision matrices.

Figure 3: ITYs Prioritization Matrix

The second level of the prioritization matrix is the ranking of the user needs within each

individual ITY. These were conducted to determine which user needs within each ITY should be

considered higher importance to design. The prioritization matrices for each ITY can be referenced

in Appendices A1-5. It should be noted that prioritization matrices for reliability and affordability

were not created since each of those ITYs contained only one user need.

Needs-Metrics Matrix

The next step towards concept development was the assignment of metrics to the user needs

that were previously identified. Each need was defined by at least one metric in a quantifiable,

qualitative, or subjective manner; this is shown through the needs-metrics matrix in Figure 4. The

common downward linear trend is present in the matrix with deviations due to a metric assigned

to multiple needs. As development of the product progressed, the need-metrics matrix concurrently

evolved due to feedback from other groups, instructors, and new research. The first iteration of the

matrix yielded metrics that were vague and could not be properly quantified. For example, the

current metrics of length, width, and height were grouped into a single metric called "Can fit an

average to large sized person." The older metric was vague since it was an agglomeration of three

separate and vital design metrics. Following a project progress review, the needs-metrics matrix

was altered and refined to add the needs of "can be cleaned" to the durability ITY and antimicrobial

to the safety ITY. Metrics of chemical resistance and microbial growth were assigned to the "can

be cleaned" and antimicrobial needs respectively. These new needs and metrics were added as a

ITY Functionality Usability Durability Safety Portability Affordability Reliability Sum Normalized (%)

Functionality 10 5 1 5 1 5 27 23.94%

Usability 0.1 0.1 0.1 0.2 0.1 0.2 0.8 0.71%

Durability 0.2 10 1 1 0.2 5 17.4 15.43%

Safety 1 10 1 0.2 0.2 5 17.4 15.43%

Portability 0.2 5 1 5 1 5 17.2 15.25%

Affordability 1 10 5 5 1 5 27 23.94%

Reliability 0.2 5 0.2 0.2 0.2 0.2 6 5.32%

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measure of the health and safety of the user since the homeless or victims of disaster may not be

able to clean themselves or their clothes. The lack of cleanliness allows for dirt, microbes, and

other contaminants to accumulate on the inside of the product and can lead to increased risk of

infection or other health concerns. Depending on the type of microbe present, the mechanical

integrity of the product can be decreased as well. The ideal and marginally acceptable metric values

corresponding to their verbal descriptions can be found in Appendix C4.

Figure 4: Need-Metrics Matrix for ThermArk

Initial Concepts

The completion of a needs-metrics matrix and the ideal/marginally acceptable values

(Appendix C4) led to the development of initial concepts. Concept generation occurred in two

stages: 1) development of concepts that fulfilled each ITY and 2) organization of each concept into

subgroups of structure, insulation, and closing mechanisms. The concepts from stage one were

discussed within the group to determine which concepts were plausible and easily produced. The

remaining concepts were organized into the sub-concepts in stage two.

Structure

The first sub-concept was concerned with the development of the structure or skeleton of

the product. The five concepts that were created were coined "livable laundry basket", "accordion

style", "garage door", "Bivy-style", and "intense sleeping bag.”

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2 No risk of suffocation x

3 Thermal protection against ground x x

4 Waterproof x

5 Windbreaker/Wind-proof/resistant x

6 Low-cost x x x x

7 Endures one month of use x x x x x

8 Can be cleaned x

9 Functions when abraded etc. x x

10 Gouge resistant x x

11 Discreet x

12 Able to see surroundings from inside x

13 Antimicrobial x

14 Breathable x x

15 Meets restrictions set by locality x

16 Locking mechanism

17 Simple packing x x

18 Lightweight x x

19 Packable to fit in small volume x x

20 Convenient to carry x x x x

21 Carry in mass transit systems x x x x

22 Survives opening and closing x x x x

23 Breathable x x x

24 Spatially efficient x x x x x

25 Expandable x x x

26 Comfortable x x x x x x

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The livable laundry basket, Figure 5, was modeled after the cylindrical laundry baskets that

contain a spiraled, flexible polymer or metal frame. This concept allows the user to rapidly deploy

the product by allowing the material-coated spiral frame to expand. When required to travel, the

user brings the ends toward each other to compress the internal spiral frame. The cylindrical

volume allows ample space when in use and compact profile when not. Drawbacks from this

concept include limited expandability and need for different materials in frame and material

between.

Figure 5: Drawing of the livable laundry basket concept

Similar to the livable laundry basket, the accordion style concept, Figure 6, folds up via

end-caps. The main differences are that the structure is a rectangular prism and is sectioned by

rigid, open-networked square frames. An insulating material is attached to each of the square

frames to create the accordion-like design. The rectangular prism shape allows the user to be

situated on a flat surface instead of the unstable curvature of the cylindrical laundry basket concept.

This structure has similar drawbacks to the livable laundry basket with the additional need for

reinforced frame corners.

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Figure 6: Drawing of the accordion-style concept

The garage door concept, Figure 7, was designed to look like a common mat but contains

a hidden compartment at the bottom: a covering which can be pulled over the mat. This covering

contains joints that allow for the covering to fold and unfold quickly as well as create a self-

supporting protective structure over the user. The mat allows for comfort and thermal protection

from the ground while the covering protects the user from wind, precipitation, and the cold air.

Folding a unit along its length would be hindered with this concept, and extra design is required

for the joints along the movable cover.

Figure 7: Drawing of the garage door concept

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A Bivy-style product, shown in Figure 8, would be a combination of a "tent" near the head

and a sleeping bag. It is designed to have lightweight supports or self-supporting, semi-flexible

material to keep the device off the face of the user. This raised material in the head area allows the

user to not feel entrapped by the product thus potentially improving the comfort, spaciousness, and

breathability of the product. Trapped air near the head area provides additional insulation. A

primary challenge with this architecture is that users may not understand how to construct the head

area of the product.

Figure 8: Drawing of the Bivy-style concept.

Unlike the previous four sub-concepts, the intense sleeping bag, Figure 9, contains no

internal framework and would be similar to a sleeping bag. The main difference to current product

is that the product would include a translucent viewing window to see out of and will be breathable

when sealed. This concept allows for a variety of user configurations, such as a blanket or enclosed

sleeping bag, to satisfy needs regardless of ability to assemble a structure. Locking components on

the sides can be used or ignored by the user.

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Figure 9: Drawing of the intense sleeping bag concept. The top view depicts the concept when

not sealed and in a blanket-like form.

Insulation

Concept generation for the insulation sub-concept yielded the five concepts coined

"Alternating Rings of Vacuum and Foam", "Water-Resistant Liner", "Emergency Blanket Liner",

"Heat Reflective Layer", and "Multi-Layer."

The "Alternating Rings of Vacuum and Foam" was designed to incorporate the heat

transfer damping potential of a system in vacuum. The structure would be comprised of insulating

foam with alternating vacuum-pulled rings down the length of the product. The vacuum sections

would allow for high thermal insulation, while the foam sections would allow for it to be

breathable. Isolating the sections from each other increases resistance to puncture.

As previously stated in this document, if the user clothes and/or protective device is

inundated with water, the ability to retain body heat is reduced almost 20 times. This requires an

insulation with a resistance to water permeation. The "Water-Resistant Liner" concept includes a

hydrophobic liner on the outside and inside of the product with insulating foam between. This

allows for protection from snowy or rainy outside environment and to ensure the foam does not

become inundated with water that may have accumulated on the user’s clothes and belongings.

The internal hydrophobic liner also allows the product to be easily cleaned, improving safety.

Emergency blankets, also known as Mylar or space blankets, are currently utilized in

emergency situations to partially cover, insulate, and reflect heat from the user when facing a

hypothermia-inducing environment. These are commonly standalone and are composed of vapor-

deposited metal on two thin polymer sheets that are adhered together [8]. The emergency blanket

liner would be thicker version of a standard Mylar blanket that is attached to the inside of the

structure. This liner would extend the length of the product and line the areas of the product that

typically line up with the greatest level of radiant heat generated from the body. This allows for

the overall product to be breathable since Mylar typically does not allow air permeation.

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Similar to the emergency blanket liner, a "Heat Reflective Layer" would be composed of a

material that reflects the user’s radiant heat. This method uses thin, flexible metal films to

accomplish this radiant heat reflectance. The metal film would be enclosed between two polymers

sheets containing a pocket of air. Sealing the metal film between two sheets protects the user from

the metal as well as protects the metal film from the environmental factors. This would be

distributed in a tight checkerboard-like pattern over the length of the product to allow for increased

breathability and effective radiant heat reflection.

The "Multi-Layer" design would be a combination of multiple insulation concepts and

materials to make an insulating layer. This design features a waterproof outer layer, a thermally

isolating foam core, and an inner layer composed of a water-resistant material coated with a

thermally reflecting material. The design is an agglomeration of the using a foam layer from the

"Alternating Rings of Vacuum and Foam", the water-resistant or hydrophobic layer from the

"Water-Resistant Liner", "Emergency Blanket Liner", and the heat reflective material used in the

"Heat Reflective Layer" concept. The multi-layer concept leads to protection from hypothermia –

inducing temperatures and water intrusion while adding a degree of comfort and support with

presence of the foam.

Closing Mechanisms Closing mechanisms are sub-concepts that can be associated with the opening and closing

operations of the future product. Button snaps, zippers, and ties, were chosen as potential options

due to their cost effectiveness and successfulness in other products such as jackets. All of these

potential methods can allow for sufficient separation of the user from the outside environment.

Application of button snaps and ties would be strategically placed on the product to minimize

unnecessary material use but maximize closure. The tie concept is a simplified tie and loop method

where fibrous or braided materials create a loop on a side of the product. On the other side, a non-

looped piece of this material is tied to the loop to create a loose seal between the two sided. Like

buttons, this would have to be repeated several times on the product surface to allow for an efficient

seal from the environment. A zipper provides the most effective seal against the environment but

has a high potential to be critically damaged and thus lose functionality.

Concept Screening and Selection

Following identification of the sub-concepts, the strengths and weaknesses of each were

identified to determine which sub-concepts should be incorporated into the final design. Concept

ratings were conducted on a scale of one to five where, a score of one signified low fulfillment of

the needs while a five signified high fulfillment of the needs; a score of three was considered a

neutral rating. These ratings were multiplied by the weight of each supergroup to facilitate

comparison among concepts. The completed matrices for each sub-concept are found in

Appendices B1-3.

Following completion of selection matrices for each sub-concept, the overall concept was

configured. The sub-concepts of intense sleeping bag, multi-layer insulation, and button snaps

were combined to create an overall concept. The selection matrix for the structure sub-concept

yielded the intense sleeping bag due to its simplicity, potential ease of manufacturability, and

proven effectiveness in similar designs. The main concerns with the other sub-concepts were that

16

increased complexity could yield more points of failure as well as rigid structures are less discreet

for homeless outside of shelters. The selection matrix for closing mechanisms yielded a tie between

ties and button snaps. Button snaps, such as in rain jackets, reliably close structures and effectively

seal a user from outside influences and were therefore chosen.

The only selection matrix that the group did not choose the highest-rated concept was for

insulation. This matrix yielded an insulator with a water-resistant liner as the choice. While this is

needed in the product, the group decided that a multi-layer insulator that combines water-proof,

heat reflecting, and windproof materials along with an insulating layer. The matrix discounted this

as a viable method due to a potential lack of portability due to a possible rigidity and weight

concern. The group decided that, through effective material selection and product architecture, the

final product will still retain a high degree of portability even with a multilayer insulation method.

Detailed Design/Concept Architecture

Material Selection

Material selection began with planning how the foam-fabric sandwich concept would be

realized. Research was divided into the functions this “sandwich” needed, such as a tough,

waterproof outer layer, foam for the inside, and a heat-reflective inner layer safe for prolonged

contact with the user. Materials used for snaps and the interface between the user and the ground

were also considered, as these have some requirements apart from the main insulating composite.

The importance of affordability for a product meant for the homeless guided materials research;

use of different materials for each layer would increase the price of the final product as economy

of scale would be diminished. Also, different materials would require different industrial controls,

such as processing temperature, and the chance of product defects would be increased.

Metrics gathered from research could not be directly applied to the metrics based on user

needs. In order to evaluate which material best satisfies the needs and metrics for our project, the

available values were related to which supergroup they apply to. For example, listed price in

USD/lb. was rated for satisfaction of the affordability supergroup. Ratings were done on a scale of

one to five, and the ratings were multiplied by the weight of each supergroup to facilitate

comparison among materials. Rated materials for each function are available in Appendix C1.

The initial material focused on which could satisfy all needs was poly (ethylene

terephthalate) (PET), since it could be cheaply processed into a solid sheet and a foam. Efforts

were made to fit PET to the user needs, such as packing the material into a small space. PET is

used to make camera film, so tightly rolling the material was possible. However, the outstanding

barrier for using PET was the polymer’s high glass transition temperature. This factor meant that

PET would be brittle at service temperatures. Also, tightly rolling the insulator would only work

to reduce size in one direction. To make progress, low-density polyethylene (LDPE) was identified

as a good material for making foam and was then considered for other functions. It was similar to

PET in price to make and process, and it would remain flexible at service temperatures. This

process taught the group to remain open-minded when choosing materials and provided experience

in considering transition temperatures as a factor in design.

LDPE was chosen above other candidate materials for how well it suits the user needs, and

its familiarity with consumers gives it tangible value. Plastic grocery bags are made from this

material, which allows research regarding safety and strength to be corroborated by personal

17

experience. Thickness of outer and inner layers is based on thickness of LDPE bags, where sturdy

plastic bags make a good approximation for the durable outer layer’s thickness [9]. Common use

of LDPE also enables the product to be manufactured from mostly recycled LDPE. The product

can be washed with water to remove grime obtained during use; LDPE often chosen as a food

container due to its lack of reactivity with organic products [10].

The foam-sheet sandwich composite cannot fully insulate a person if that material needs to

pack into a small volume. Therefore, a heat reflective coating was incorporated between two thin,

transparent layers of LDPE on the interior. A metallized film can properly adhere to polymers.

Several metals may be used for a heat-reflective coating, including nickel, aluminum, and

chromium [11-13]

However, aluminum was chosen due to its price and lack of health risks when in contact

with skin [14]. An inner layer of LDPE keeps the metallized film out of contact with the skin, and

a metal with no major health risks is chosen in case the LDPE sheet is abraded. The inner layer

also protects the user if the metal loses adhesion with the polymer matrix [11].

Final Product Description

The user needs heavily influenced the final architecture of ThermArk. The design is a

multi-layer composition that can be used as either a blanket, or be folded into a sleeping bag. The

final architecture has the layer adjacent to the user as extruded LDPE with a thickness of 0.001

in., with those divided into two 0.0005 in. thick sheets where one is aluminized. The aluminized

sheet is separated from the user by the inmost layer of thin, transparent LDPE. The aluminized

sections are 5x5in with a 1 in. gap between each square with a thickness of 0.00064 in. The inner

foam layer is extruded LDPE foam with a thickness of 0.25 in. The layer in contact with the

environment is extruded LDPE with a thickness of 0.0025 in. and dark gray color. A total of 14

snaps, composed of injection molded PVC, provides a durable yet cost-effective sealing method.

The sides are 13 in. apart from each other, and the top and bottom are 22 in. apart.

The design can be envisioned through the CAD rendering in Figure 7. The user needs

from Figure 2 heavily influenced the material chosen for the product, and the industrial design

considerations and rankings are shown in Appendix C2. The materials utilized in the ThermArk

had to fulfill all the needs, while concurrently and effectively being thermally insulating and

affordable. Due to this hurdle, it was decided to use cost-effective and commonly recycled

materials such as LDPE and PVC. It was determined through research and analysis that the

number of components in the product can define if the product will be affordable, especially

when concerning the market. As seen on Figure 10, the lack of a viewing window deviates from

the original final concept design. The removal of the viewing window was decided due to an

increased amount of parts and complexity. This leads to an increase in material cost,

manufacturing costs, points of failure, and carbon footprint.

18

Figure 10: CAD rendering of the ThermArk Thermal Insulator

Comparison to the Current Market

In comparison to what is currently on the market, ThermArk is different in many ways.

First, it is produced with materials that have a high thermal conductivity, but are cost-

effective compared to commonly used insulation in the competition. Secondly, the design allows

it to be used as either a blanket or a sleeping bag/tent hybrid. The snaps and material allows the

user to choose how they want to use the ThermArk, and are not restricted to one

configuration. The third benefit was the material and the design. The product is

very lightweight and easy to pack when not in use. LDPE was used along

with aluminized squares to provide insulation while allowing the product to maintain portability.

Compared to sleeping bags, tents, and blankets, this is less bulky and lighter weight. Lastly,

compared to our competitors, ThermArk can be downcycled and the LDPE used again in another

product. This is not always true for blankets, certain tent materials, and commonly used sleeping

bag materials.

Manufacturing Process

Materials selection included consideration for manufacturing, which excluded materials

such as woven jute for its unreliable bonding with waterproof layers. Hot bar welding can be used

for thermoplastic polymers such as LDPE, and it works by pressing the materials to be welded

between two electrically heated bars. Figure 11 shows a configuration which can weld together

layers of insulating composite. Two benefits arise from using hot bar welds to create a grid of

bonded layers: metallized sections can be included between the grid lines, and un-welded sections

can stretch to make additional, insulating air pockets. Prior to welding layers together, LDPE can

be extruded into solid and foam sheets.

19

Figure 11: Hot bar welding schematic [18].

Metallizing the intermediate LDPE layer is done by physical vapor deposition. This

requires the metal to become atomized and travel through vacuum to the substrate to create a

reflective coating on that substrate [15]. At first, this process was avoided since using vacuum was

considered too expensive, but following research and discussion revealed that there are existing

cheap products which use this method. Metallizing the single LDPE layer is done after cooling

from extrusion and before stacking layers for hot bar welding.

One possible manufacturing supply chain arranges extrusion of each layer vertically, with

the thin LDPE layers at the bottom of a manufacturing tower. This allows extra equipment for

metallizing an LDPE layer to be located at a minimal height from the ground. These layers will

continue in a straight line and meet before hot bar welding is done, and the snaps will be riveted

on after cooling from hot bar welding. Individual blankets can be cut apart and folded when all

steps are finished. Quality assessment can be done using the finished product, as functional layers

can be separated where not welded. Figure 12 summarizes manufacturing and materials cost as a

Bill of Materials.

Figure 12: Bill of Materials for ThermArk

Purc

hase

d m

ater

ials

(Ave

rage

USD

/ite

m)

Proc

essi

ng

(Mac

hine

+Lab

or)

Ass

embl

y (la

bor)

Tota

l Uni

t va

riabl

e co

stTo

olin

g an

d N

REs

Tool

ing

lifet

ime

(yr)

Tota

l uni

t fix

ed c

ost

(per

year

)

Tota

l cos

t

6.05x + 2104 (USD/yr)

PVC Snaps 0.0429 0.0167 0.0444 0.1040 3770 5 754

Outer, Inner LDPE shells 0.7087 0.0167 0.0056 0.7309

LDPE foam 4.7695 0.0167 0.0056 4.7917

Aluminum heat reflector 0.2555 0.1667 0.0056 0.4277 1000 3 350

Total 6.0543 2104 x = # units per yearLabor set at $20 per hour

6.05x + 2104 (USD/yr)3000 3 1000

20

Sustainability Assessment

A major consideration in the 21st century is environmental impact of producing industrial

and consumer products. Resources such as CES EduPack 2016 list carbon footprint by mass of

material produced, allowing the pounds of carbon dioxide produced with a new product to be

estimated. ThermArk, which weighs approximately five pounds, will contribute 20.1 – 23.4

pounds of carbon dioxide for each unit produced. For scale, one jacket currently produced as a

consumer product contributes 66 pounds for each unit [16], and a gallon of dairy milk creates about

7.2 pounds of carbon dioxide. Additional considerations into sustainability are listed in Appendix

C3. Including all considerations, mass production of the product is not expected to create a

significant detriment to natural resources and environment.

Feasibility Assessment

Final metrics for the product along with the ideal and acceptable values are shown in

Appendix C4. Values which could not be exactly computed are estimated based on research into

similar products, and any assumptions made to reach the final metrics are listed.

The product specifications fall within ideal and acceptable ranges for all properties except

the metric corresponding to most important user need: thermally insulating. This results from the

need to satisfy other needs, especially affordability and portability. Building a shelter to completely

insulate a rough sleeper requires far more energy than is available in producing and using the

product. Despite providing incomplete insulation, the product has waterproofing and heat-

reflective capabilities which improve the product from simple blankets used by homeless. The

primary condition of market feasibility for this product is that it satisfies the need to keep a user

alive in winter months. Satisfaction of that need requires that the user has other systems which

help insulation, such as warm clothing and some air between the user and the product. The user

may use a simple blanket with the product, further increasing his or her warmth.

Economy of scale aids financial feasibility, where production of 500,000 units per year

allows each unit a retail cost of $15. However, this price is steep for a product which is intended

to be purchased on a large scale by relief agencies. One option to relieve this problem is to sell

ThermArk to our secondary market for $30 and advertise that each blanket bought sends a blanket

to relief services.

21

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23

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24

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25

Appendix

Appendix A: Prioritization Matrices

Figures A1-5 contain prioritization matrices for all user needs within each supergroup

with more than one associated need.

Figure A1: Prioritization matrix for the functionality ITY

Figure A2: Prioritization matrix for the usability ITY

Figure A3: Prioritization matrix for the durability ITY

Figure A4: Prioritization matrix for the safety ITY

Figure A5: Prioritization matrix for the portability ITY

Thermally insulating Wind-proof/resistant Waterproof Thermal protection from ground No risk of suffocation Sum Normalized (%)

Thermally insulating 5 5 1 1 12 33.33%

Wind-proof/resistant 0.2 0.2 1 0.2 1.6 4.44%

Waterproof 0.2 5 1 0.2 6.4 17.78%

Thermal protection from ground 1 1 1 1 4 11.11%

No risk of suffocation 1 5 5 1 12 33.33%

Breathable Expandable Comfortable Spatially efficient Sum Normalized (%)

Breathable 5 5 5 15 45.59%

Expandable 0.2 5 1 6.2 18.84%

Comfortable 0.2 0.2 0.1 0.5 1.52%

Spatially efficient 0.2 1 10 11.2 34.04%

Endures one month of use Gouge-resistant Retains functionality when abraded Can be cleaned Sum Normalized (%)

Endures one month of use 5 1 1 7 32.41%

Gouge-resistant 0.2 0.2 1 1.4 6.48%

Retains functionality when abraded 1 5 0.2 6.2 28.70%

Can be cleaned 1 1 5 7 32.41%

Condensation can escape Discrete Can see surroundings from inside Meets local restrictions Locking mechanism Antimicrobial Sum Normalized (%)

Condensation can escape 0.1 0.1 1 5 0.2 6.4 8.53%

Discrete 10 1 5 5 1 22 29.33%

Can see surroundings from inside 10 1 5 5 0.2 21.2 28.27%

Meets local restrictions 1 0.2 0.2 1 0.2 2.6 3.47%

Locking mechanism 0.2 0.2 0.2 1 0.2 1.8 2.40%

Antimicrobial 5 1 5 5 5 21 28.00%

Convenient to carry Packable Simple packing Carry in mass transit systems Lightweight Sum Normalized (%)

Convenient to carry 1 0.2 10 0.2 11.4 19.96%

Packable 1 1 5 5 12 21.02%

Simple packing 5 1 10 1 17 29.77%

Carry in mass transit systems 0.1 0.2 0.1 0.1 0.5 0.88%

Lightweight 5 0.2 1 10 16.2 28.37%

26

Appendix B: Concept Selection Matrices

Figures B1-3 contain selection matrices for product architecture, insulation, and accessories.

Figure B1: Concept selection matrix for the structure sub-group

Figure B2: Concept selection matrix for the insulation sub-group

Figure B3: Concept selection matrix for the closing mechanism sub-group

Appendix C: Detailed Design and Project Architecture

Appendix C1: Material Selection Figures C1.1 – C1.5 show the decision matrices for bottom, outer layer, inner layer, foam, and

accessory materials, respectively. Not all best materials based on ratings were used because the

design assumption was to use one material to satisfy all needs.

27

Figure C1.1: Materials selection matrix for layer between user and ground

(Ensolite) PVC/NBR Elastomer Woven Jute with Natural Rubber Neoprene

Price (USD/lb.) 1.85-2.10 0.159-0.68/0.862-1.09 2.4-2.8

Density (lb./in^3) 0.0397-0.0452 0.047-0.0542/0.336-0.035 0.0488-0.0542

Yield strength (ksi) 1-2.47 21-76.9/3.04-4.06 1.52-3.09

Fatigue strength at 10^7 cycles 0.4-0.986 23.2-49.9/1.22-1.62 0.661-1.24

Flexural Strength (ksi) 2.31-4.48 NR/5.34-6.85 3.27-5.41

Tear Strength (lbf/in) 143-240 NR/142-251 154-320

Tg (deg F) -9.4 - - 0.4 716-734/-108- - 81.4 -54.4- - 36.4

Thermal conductivity (BTU.ft/hr.*ft^2*F) 0.0867-0982 0.144-0.202/0.0751-0.0924 0.116-0.52

Water absorption at 24 hr. (%) 0.05-0.3 2.2-2.6/0.01-0.02 0.6-0.8

O2 Permeability (cc.mil/day*(100in^2)*atm) 61-254 NR/2.5e3-4.17e3 55-172

Water vapor transmission (g*mm/m^2*day) NR NR/11-21 NR

Chemical resistance Acceptable Limited on own/ Excellent together Excellent

Carbon footprint (lb./lb.) 3.18-3.5 2.69-2.96/1.86-2.05 2.08-2.29

Other

Excellent to extrude, not

recycled often, can be burned

for energy recovery, Issue with

Tg

Jute on its own is very biodegradable,

can weave/ extrudable but not

biodegradable; Together they are able

to be burned for energy recovery. Need

antioxidant

Extrudable, Not

recyclable and mainly

goes to landfill. Can be

burned for energy

recovery. (w/Carbon

Black)

Source CES EDUPACK 2016 CES EDUPACK 2016 CES EDUPACK 2016

Functionality 4 4 3

Affordability 4 5 3

Durability 4 5 4

Safety 3 4 4

Portability 3 3 3

Reliability 3 4 3

Usability 4 4 4

Weighted sum 348.12 402.92 315.67

LDPE Foam HDPE Foam PET Foam Cork

1.18-1.31 1.25-1.38 4.65-5.11 1.22-6.08

0.00246-0.0026 0.00361-0.00415 0.0113-0.0118 0.00578-0.0867

0.00406-0.00508 0.087-0.102 0.307-0.372 0.0435-0.104

0.0725-0.087 0.319-0.363 NR 0.0435-0.087

0.00406-0.00508 0.087-0.102 0.307-0.372 0.0725-0.174

NR NR NR NR

-193- -130 -193- -130 140-183 171-216

0.0289-0.03 0.0416-0.0451 0.0229-0.0253 0.0202-0.0243

0.4-0.5 0.5-0.7 0.14-0.18 NR

NR NR NR NR

NR NR NR NR

Acceptable Acceptable Acceptable Acceptable

4.86-5.36 4.5-4.96 7.27-8.01 0.192-0.211

Extrudable, not very

recyclable (~8-9% recycled),

can be burned for energy

recovery; Considered

adding aluminized surface

Extrudable, not very recyclable

(~8-9% recycled), can be burned

for energy recovery; Considered

adding aluminized/metalized

surface

Huge Carbon Footprint is a

negative. Can burn for energy

recovery. 20-22% of supply is

recycled. Metalize the

surface?

Biodegrades and can have

wide range of densities and

properties. Naturally

occurring. May not "roll-up"

or fold well with multiple

uses.

CES EDUPACK 2016 CES EDUPACK 2016 CES EDUPACK 2016 CES EDUPACK 2016

5 4 5 5

4 4 2 3

2 3 3 3

3 3 2 5

5 5 4 4

5 5 2 2

4 4 4 3

371.7 363.19 308.57 378.09

28

Figure C1.2: Materials selection matrix for layer in contact with outside environment

Figure C1.3: Materials selection matrix for layer in contact with user

PA12 (flexible) PA12/E-glass

Polyester (cast,

flexible) PET (unfilled)

PVC (flexible,

shore A60)

PE-LD (molding and

extrusion)

Price (USD/lb.) 4.72-5.67 3.84-4.16 1.84-1.89 0.658-0.803 1.12-1.33 0.903-1.1

Density (lb./in^3) 0.0372-0.0376 0.0614-0.065 0.03650.0434 0.0466-0.0502 0.0444-0.0448 0.0331-0.0337

Yield strength (ksi) 3.19-3.63 52.2-58 1.16-2.4 7.25-7.98 1.45-1.6 1.3-2.1

Fatigue strength at 10^7 cycles 2.32 31.3-34.8 0.87-1.2 2.8-4.2 1.09-1.2 0.77-1.53

Tg (deg F) ~100 C 120 F 302 F 140 -9.4-8.6 F -193-(-130)

Thermal conductivity (BTU.ft/hr.*ft^2*F) 0.126--0.177 0.374-0.464 0.0892-0.0928 0.0797-0.0872 0.0924-0.116 0.186-0.201

Water absorption at 24 hr. (%) 20.00% 0.35-0.424% 0.5-2.5% 0.14-0.18 0.5-0.52 0.005-0.01%

Water vapor transmission 0.28 NR NR 0.464-0.707 NR 0.248-0.506

Chemical resistance Acceptable Acceptable Acceptable Highly flammable Acceptable Highly flammable

Carbon footprint (lb./lb.) 7.25-7.99 6.22-6.86 2.41-2.66 4.28-4.72 2.24-2.47 2.86-3.15

Other

Recyclable;

cannot

biodegrade;

(flexible)

Not recyclable or

biodegradable; (E-

glass fiber, woven

fabric laminate,

biaxial lay-up)

Not recyclable or

biodegradable;

(cast, flexible)

Recyclable; cannot

biodegrade;

(unfilled,

amorphous)

Recyclable;

cannot

biodegrade;

(flexible, Shore

A60)

Recyclable; cannot

biodegrade.

Processable by hot

welding.

Source CES Edupack CES Edupack CES Edupack CES Edupack CES Edupack CES Edupack

Functionality 1 3 4 5 4 5

Affordability 1 2 4 5 4 5

Durability 3 5 1 2 1 1

Safety 3 3 4 2 5 3

Portability 5 2 5 4 4 5

Reliability 2 2 2 2 2 4

Usability 3 3 3 4 3 3

Weighted sum 229.48 286.41 357.69 375.6 357.87 400.78

PET PET Alumina Foam

Zirconia Mullite

Alumina Foam

Aluminum-

polyethylene sandwich

Price (USD/lb) 0.658-0.803 0.658-0.803 15.1-22.6 9.41-11.3 9.54-12.2

Density (lb/in^3) 0.0466-0.0502 0.0495-0.0506 0.0235-0.0303 0.0206-0.246 0.0496-0.0507

Yield strength (ksi) 7.25-7.98 9.43-10.2 0.131-0.319 0.116-0.261 7.25-10.2

Fatigue strength at 10^7 cycles 2.8-4.2 2.8-4.2 0.155-0.171 0.132-0.146 4.35-5.8

Flexural Strength (ksi) 7.25-8.7 10.2-10.9 0.145-0.421 0.167-0.261 24.7-26.1

Tg (deg F) 140-183 154-176 478-496

Thermal conductivity (BTU.ft/hr*ft^2*F) 0.0797-0.0872 0.0797-0.0872 0.289-0.385 0.192-0.289 0.31-0.335

Water absorption at 24 hr (%) 0.14-0.18 0.1-0.2 0.5-1 0.5-1

Chemical resistance Acceptable Acceptable Excellent Excellent Excellent

Carbon footprint (lb/lb) 4.28-4.72 4.28-4.72 6.33-6.99 4.62-5.1 7.46-8.23

Other (unfilled,

amorphous)

Crystalline (nucleated)

PET is more heat resistant

than the amorphous

grades, but is not

transparent. Unfilled PET

is problemtatic to

injection molded

compared to unfilled PBT;

(unfilled, semi-crystalline)

(99.5%)(0.745) 0.63

Source CES Edu Pack CES Edu Pack CES Edu Pack CES Edu Pack CES Edu Pack

Functionality 5 5 2 3 4

Affordability 5 5 1 2 2

Durability 2 2 2 2 5

Safety 2 2 4 4 3

Portability 4 4 4 3 2

Reliablilty 4 4 4 4 3

Usability N/A N/A N/A N/A N/A

Weighted sum 383.4 383.4 246.68 279.31 313.54

29

Figure C1.4: Materials selection matrix for foam insulation

Figure C1.5: Materials selection matrix for snap fasteners

Polyurethane Foam Polyimide Foam (Solimide) LD Polyethylene Foam PET Foam (Armacell ArmaFORM)

Price (USD/lb.) 3.46-3.81 10-75 1.18-1.31 4.65-5.11

Density (lb./in^3) 0.00271-0.00307 0.000231 0.00246-0.0026 0.0113-0.0118

Yield strength (ksi) 0.00363-0.00435 N/A 0.00406-0.00508 0.307-0.372

Fatigue strength at 10^7 cycles 0.0127-0.0152 N/A 0.0725-0.087 N/A

Flexural Strength (ksi) 0.00363- 0.00435 N/A 0.00406-0.00508 0.307-0.372

Tg (deg F) -27.4- - 9.4 N/A -193- -130 140-183

Thermal conductivity (BTU.ft/hr.*ft^2*F) 0.0139-.0162 0.043 0.0289-0.03 0.0229-0.0253

Water absorption at 24 hr. (%) 8-10% N/A 0.4-0.5 0.14-0.18

O2 Permeability (cc.mil/day*(100in^2)*atm) NR N/A N/A N/A

Water vapor transmission (g*mm/m^2*day) NR N/A N/A N/A

Chemical resistance  Below Average to Acceptable  Limited use to Acceptable Acceptable Acceptable

Carbon footprint (lb./lb.) 4.95-5.46 No 4.86-5.36 7.27-8.01

Noise reduction Coefficient Unknown 0.75 N/A N/A

Other

Water absorption is high. Can

be extruded and molded.

Recycling is limited but can be

burned. Can be

downcycled! High water

absorption would increase

thermal conductivity and

weight over time

So good that NASA uses it;

single source since

proprietary things; seems

aimed at big industry =

very expensive; was not

able to find the foam on

CES EDUPack. PI is

extremely expensive and

out of our price range

Extrudable, not very

recyclable (~8-9%

recycled), can be burned

for energy recovery; Can

be downcycled!

Huge Carbon Footprint is a

negative. Can burn for energy

recovery. 20-22% of supply is

recycled. Can be downcycled as

well.

Source CES EDUPACK 2016 CES EDUPACK 2016 CES EDUPACK 2016

Functionality 2 3 4 4

Affordability 4 1 5 3

Durability 3 1 3 4

Safety 2 2 4 3

Portability 4 5 4 3

Reliability 3 1 5 3

Usability 3 4 3 3

Weighted sum 2.9988 2.2646 4.132 3.3943

Snaps Brass ABS PVC (rigid molding) PLA PP POM

Price (USD/lb.) 2.72-2.99 1.13-1.36 0.762-0.93 1.27-1.55 1-1.1 1.53-1.66

Density (lb./in^3) 0.308-0.314 0.0376-0.0387 0.047-0.0538 0.0448-0.0456 0.0325-0.0328 0.0509-0.517

Yield strength (ksi) 17.4-20.3 6.09-6.67 6-7.64 7.98-10.4 4.77-5.28 9.5-10

Fatigue strength at 10^7 cycles 21.8-22.6 2.04-2.65 2.4-3.06 3.22-4.02 2.13-2.24 3.46-4.49

Fracture Toughness( Ksi/in) 59.6-64.1 1.73-1.91 3.3-3.5 3.04-4.36 1.92-2.02 3.46-3.82

Tg (deg F) NR 212-230 176-190 126-140 6.8-21.2 -76 - -58

Chemical resistance Excellent Acceptable Excellent Acceptable Excellent Acceptable

Carbon footprint (lb./lb.) 0.973-1.08 1.17-1.29 0.947-1.05 0.9-0.995 1.06-1.17 1.67-1.84

Other

CuSn20; Can be

plated; recyclable,

press forming but

not castable

Excellent choice

for ease of

manufacture (can

mold, extrude, and

thermoform); can

recycle or burn for

energy recovery

Injection

Moldable; can

recycle or burn for

energy recovery

Acceptable choice for

manufacturing (can

mold, extrude, and

thermoform); Excelle

nt for recycling; can

biodegrade

Excellent choice

for ease of

manufacture (can

mold extrude, and

thermoform); Can

recycle and can

burn for energy

recovery

Injection

Moldable; can

recycle or burn for

energy recovery

Source CES EDUPACK 2016 CES EDUPACK 2016 CES EDUPACK 2016 CES EDUPACK 2016 CES EDUPACK 2016 CES EDUPACK 2016

Functionality 4 3 3 4 2 3

Affordability 1 3 5 2 4 5

Durability 5 3 3 4 3 3

Safety 4 2 4 3 3 1

Portability 2 5 4 4 5 3

Reliability N/A N/A N/A N/A N/A N/A

Usability N/A N/A N/A N/A N/A N/A

Weighted sum 289.07 297.04 360.53 312.65 312.47 298.99

30

Appendix C2: ID Charts

Figure C2.1 shows industrial design basis for the final product architecture.

Figure C2.1: Industrial design chart

Quality of User

Interface

Emotional Appeal

Ability to Maintain

and Repair the

Appropriate Use of

Resources

Product

Differentiation

Numeric rating

Performance

rating Explanation of score

Quality of User

Interface7

Interface allows user to get functionality with or without knowing how to use the snaps

on the side

Emotional Appeal 2Emotional appeal comes from helping the user survive, but product is designed to avoid

prolonging users' homeless condition

Ability to Maintain

and Repair the

Product

4Primarily made of materials which can be effectively washed with water. Stretched LDPE

cannot be returned to its unstretched state

Appropriate Use of

Resources10

No excess material is used on this product, with the exception that the user chooses to

not use the snaps

Product

Differentiation6

Product is very much like a blanket, but is set apart by waterproofing and cushioning

from the ground.

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Quality of User Interface

Emotional Appeal

Ability to Maintain and Repair the Product

Appropriate Use of Resources

Product Differentiation

Percent importance

Performance Rating

31

Appendix C3: Sustainability Figure C3.1 shows considerations for designing a sustainable product and what factors of the

product qualify for or against sustainability.

Figure C3.1: Design for sustainability matrix

Appendix C4: Final Ideal and Marginally Acceptable Metrics Figure C4.1 is the matrix of final product property specifications for ideal and marginally

acceptable values. Assumptions for calculations are included. Ideal and acceptable values were

determined when metrics were defined for the needs-metrics matrix [18-40]

Additional assumptions for the thermally insulating metric were made to account for heat

reflection. The aluminized surface covers approximately 70% of the surface area, and near 100% of

heat generated by the user is expected to be reflected by aluminized sections. Energy transfer per

hour was therefore reduced by 70% of 330 BTU/hr produced by the user [17].

Product Score ThermArk

Inherent Rather Than

Circumstantial

Designers need to strive to ensure that all materials

and energy inputs and outputs are as inherently

nonhazardous as possible.

Yes

No hazardous waste produced in

manufacture, and product materials are

chosen to minimize health risk

Prevention Instead of

Treatment

It is better to prevent waste than to treat or clean up

waste after it is formed.Yes

Process does not produce any harmful

emissions to be scrubbed

Design for Separation

Separation and purification operations should be

designed to minimize energy consumption and

materials use.

Yes Easily separated marterials used.

Maximize Efficiency

Products, processes, and systems should be

designed to maximize mass, energy, space, and time

efficiency.

Yes Product and process designed to

maximize efficiency

Output-Pulled Versus

Input-Pushed

Products, processes, and systems should be "output

pulled" rather than "input pushed" through the use

of energy and materials. Demand-Driven Production

No Market demand and production are

based on emergency preparation.

Conserve Complexity

Embedded entropy and complexity must be viewed

as an investment when making design choices on

recycle, reuse, or beneficial disposition.

Yes Fabricated from one material so it can be

recycled without separation

Durability Rather Than

Immortality

Targeted durability, not immortality, should be a

design goal.No Not biodegradeable but recyclable

Meet Need, Minimize

Excess

Design for unnecessary capacity or capability

solutions should be considered a design flaw.Yes

No extra "bells and whistles" and is a

"one-size fits all" configuration

Minimize Material

Diversity

Material diversity in multi-component products

should be minimized to promote disassembly and

value retention.

Yes Three materials are used: LDPE, PVC, and

aluminum

Integrate Material and

Energy Flows

Design of products, processes, and systems must

include integration and interconnectivity with

available energy and materials flows.

Yes Product and energy move linearly

through assembly

Design for Commercial

"Afterlife"

Products, processes, and systems should be

designed for performance in a commercial

"afterlife."

Yes May be recycled

Renewable Rather

Than Depleting

Material and energy inputs should be renewable

rather than depleting.Yes

Material can be made of recycled

material

Sustainability Measure

32

Figure C4.1: Final product metrics

Metric Description Unit Final Product Ideal Values Marginally Acceptable Values Calculation Assumptions

Thermally insulating BTU/hr 1315.8-1258.9 300-400 400-700

Temperature difference is 50 degrees Fahrenheit, 70%

of heat reflected back to user. Surface area between

user and environment is estimated at 2 m² (21 ft²).

Internal Temperature ˚F 60 70 60-75

Breathable mL/hr 0.00027 0.00125 0-0.00125

Water-Resistance % Water absorption

@ 24 hours0.01% <1% 1-3%

Wind-breaking mph 50 35+ 35-60

Consumer Cost $ $12 <$5 $5-30 Average price with 300,000 units produced per year

Cost to Manufacture $ per unit $10 <$1 $1-15 Average price with 300,000 units produced per year

Cost of Distribution $ per unit $2 <$1 $1-1220% of average price with 300,000 units produced per

year

Percent Recycled

Materials Used% 0-100% 100% 50-100% Can use recycled material

Lifetime of product Days 25-40 40 25-40 Depends on use

Use Cycles until failure Discrete 90(-20) 120 90 (-20)

Material Strength Yield strength, ksi 1.3-2.1 5+ 2 +/ 3 Strength of outer LDPE sheets

Load required to open Load, kg 0-10 15 0-10 Can be increased with using snaps

Chemical Resistance Acceptability Acceptable. Excellent Acceptable Acceptability reduced because highly flammable

Visibility subjectiveGray color on outside

layerN/A

Avoid colors such as red in high amounts of light

and yellow in low light. Shades of blue, grey,

black, and green are less visible at distances.

Ensure no reflective material is used.

User Visibility Binary Yes Yes Yes or no Limited to opening near head

Microbial Growth CFU's/mlCan be washed to

remove bacteria0 Washable

Legality Unitless, binary Meets Meets Meets or does not meet

Steps to set-

up/breakdownsteps 2-5 4 2-4 Depends on snap use

Time to set-

up/breakdownminutes 1.5-8 1 "1 -14 Depends on snap use

No unused material on

productUnitless, binary Meets Meets

The thermal blanket accomplishes its task with

minimal amounts of extra materialExtra material used as extra layers of insulation

Volume when packed ft^3 3.672 0.706 .706-3.88Assumes foam can be elastically compressed to 1/3 of

unloaded volume

Weight lb 4.94-4.71 4.4 11 +/- 5

Follows rules for

MARTA, bus, etc.Unitless, binary Meets Meets Meets or does not meet

Conducive to Sleep subjectiveProvides some

cushioningN/A Allows user to get 7-9 hours of sleep

Internal Relative

Humidity% 30-60 50 30-60 Can adjust humidity by exchanging air with outside

Length ft 7 6.56 5.6-6.2

Width ft 6 2.78 2.16-2.78 Can be folded over

Height ft 6 2.25 2.25-2.165 Allowed by wrapping

Sound Dampening Db 30-50 <30 30 - 50 Used as sound dampening in buildings