the challenges of designing & developing plastic aerosols

providing packaging solutions through engaged hearts and mindsTM

The Challenges of Designing & Developing Plastic Aerosols for a Global Market

Richard C. Darr VP Global Packaging Development October 2018

Our Company

• Family owned and managed

• Founded in 1967

• 2017 revenue : $2.7 billion

• Over 40 billion units produced annually

• 6,600 associates worldwide

• Over 40 production sites globally

• 5 + billion bottles recycled annually

• Over 1,500 patents globally

A Global Business

• 58% of Global Business

• Founded in 1967

North America

• 4% of Global Business

• Entered Market in 1997

South America

• 37% of Global Business

• Entered Market in 2005

Europe & Africa

• 1% of Global Business

• Entered Market in 2015

Asia

Global Revenue 2017 - $2.7 billion

Why use a PET aerosol container?

Shelf impact

Low carbon

footprint

Lightweight

Different!

Innovative

Versatile / shape

flexibility

PET Aerosol Containers

Technical challenge Regulatory limitations

Legislative

Constraints

Plastic Aerosol Regulation Accuracy or Ambiguity?

• Plastic aerosol containers are in the market today

• Current legislation worldwide allows plastic containers up to 500ml brimful volume (except Europe and parts of Asia)

• Plastic containers up to 1000ml brimful volume became standard in North America, based on British standard

• European Commission asked for harmonisation with global regulations in 2005

• FEA supports plastic cans up to 800ml and increased pressure up to 13.2 bar (with compressed gasses)

Regional Legislative Overview

• U.S. DOT (Department of Transportation) Outlines the various testing procedures

• NFPA (National Fire Protection Association) 30B:

– Fire & explosion prevention

– Applies to all areas of manufacturing & storage facilities

• No stated legislative requirements within most LATAM countries for Plastic Aerosols

• Requirement to place a safe aerosol on the market

• Major brand owners follow DOT or ADD regulations

• Regulated by the Aerosols & Dispensing Devices Directive (ADD 75/324/EEC and revision in 2008)

• Plastic aerosols treated like glass aerosols

• Size limitations

– ≥50ml, ≤220ml

• Pressure limitations

PET Aerosols:

Design &

Development

Challenges

• PET

• Mechanical performance

• Barrier performance

• Thermal characteristics

PET Material

PET: Polyethylene Terephthalate

A thermoplastic polymer resin of the polyester family

PET

Packaging material barrier properties

Oxygen p

erm

eabilit

y (

cc/m

².day.b

ar)

Water permeability (gr/m².day)

0.01 0.01 0.1 1 10 100 1000 10000

0.1

1

10

100

1000

10000 LDPE

PP

PET

PEN

HDPE

MxD6

COC

LCP

EVOH

PS PC

PA6

Cellulose

Starch

Film thickness : 100 µm

PET has an excellent gas barrier

Tg. Glass transition temperature

PET = 70-75°C The glass transition temperature is the temperature below which

the physical properties of amorphous materials vary in a manner

similar to those of a solid phase (glassy state), and above which

amorphous materials behave like liquids (rubbery state).

Tc. Crystallization temperature

PET = 140-160°C The temperature at which a crystalline resin begins to crystallize

upon cooling.

Tm. Melting temperature

PET = 245-255°C The temperature at which a material turns suddenly from solid to

liquid.

Sidel Source

Thermal Characteristics

• A machine that injects a preform and blows a container within the one machine

• Suitable for small volumes

ISBM Single stage or One-Step Technology

Injection Stretch Blow Moulding (ISBM)

ISBM 2 step technology

1. Preform injection

2. Container blowing

Manufacturing SprayPET® Plastic Aerosols

PET Resin Drying

PET Resin Extrusion

PET Resin Injection

Preform Cooling

The injection process

Preform Injection

Why the need for drying?

1. Degradation of PET due to water (hydrolysis – IV drop)

2. Hazy preform due to crystallization

3. 40% of energy to heat the pellets is supplied through the dryer

Residence time

4 – 6 hours

Less 40ppm

160-175oC

Dew point: max -30oC

Dryer

Resin drying is essential for high quality preform moulding

Preform Injection

Preform Injection

Opening and

Part Removal

Mould

Close Shutter-

In/Clamp-Up

Inject Hold Cool

Dry Cycle

Process Cycle

Cycle Compression (Cycle Time Saving)

SHOOTING POT

The blowing process

We all have done it!

Container Blowing

Container Blowing

Preform Heating

Preform Stretching

Preform Blowing

Bottle Cooling

The blowing process

Start Stretching

End Stretching

8 bar

40 bar

Bottle Temp < 75°c

Stretching Stretching & Pre-Blow

End Stretching & Pre-Blow

Blowing Exhaust

Container Blowing Process

The Key Technical Challenges

Ability to withstand

high pressures

Material resistance to

extreme temperatures

Ability to withstand

impact from dropping

Technical Challenge in Context

In Europe Plastipak aerosol containers are rigorously tested to draft FEA standard 647 part 1

Pressurised to c. 2 -3 bar Pressurised to c. 10 bar

Ability to withstand high pressure

• Dependent on desired burst pressure, specific hydraulic pressure applied and held for 25 seconds

• Pressure then increased until container bursts

• To pass, burst point must be 20% higher than hydraulic pressure

• Must pass burst test without splintering

SprayPET® Achieves Burst Pressure up to 27bar/390psi

Resistance to Heat

• FEA proposed testing

• Under test, filled & pressurised aerosols must not burst or leak

– Water bath: 55oC for 10 minutes

– Hot air testing: placed in an oven at 65oC for minimum 5 hours. Deformation is allowed

Resistance to Heat

Drop Resistance

• Containers filled with antifreeze or water

• Held at -18oC for 24 hours and 55oC for 6 hours

• Then dropped from height of 1.8m on to concrete floor

• Containers must not burst or leak

Drop Resistance

Summary of Plastipak’s extensive testing

Test Result

Hydraulic test Pass @15.0 bar

Burst test Max 27.0 bar/390psi

Drop test (all temperatures)

Pass

Hot air 65°C Pass (5h)

Top load Min 100.0 kgF

Stress cracking Pass with NaOH

Applies to SprayPET

220ml container

Other

Perceived

Challenges

Compatibility with propellants

• Compressed gasses

• Non-flammable combinations of liquid propellants

• Hydrocarbons

– PET has a good chemical resistance to butane and propane

• DME not compatible

Content Compatibility

• PET aerosols compatible with many products – but not everything

• Compatibility testing required for each project

• Reformulation an option with challenging contents

Decoration

Sleeving

• Containers can be sleeved without issue

• Sleeve manufacturer tested sleeved containers in 55oC water bath for 10 minute, 1 hour, 2 hour & 3 hour periods:

– No detrimental impact observed

Printing

• Printing is fully possible on PET containers

• Printing on different shapes is possible – not just straight sided cylinders

• Plastipak offers 4 colour, high-speed silk screen printing

• Used effectively for premium brands

Direct Object Printing

• Successfully launched in the USA and currently in development in Europe

• Real “no label” look

• Mass customisation

• Reduced waste

• Enhanced customer engagement

• Faster speed to market with inline variable data print

• Instant change over

Some Initial Different Designs

• Easy to implement

• Change of blow moulds required

– Preform changes may be required subject to design

– Cost dependent on volumes / blowing machine

• How much value do you put on shelf presence / differentiation?

Complexity of Customised Shape?

Case study

• Launched in US January 2017

• PET container supported by HDPE base cup

• Sleeve decoration

Plastic Valves

Summary

Different legislation

regionally – largely

supportive

Comprehensive

testing regime in

place

Decoration not an

issue

Propellant & product

compatibility OK