utilizing equipment, lift trucks, racks and shelving

8/12/2019 Utilizing Equipment, Lift Trucks, Racks and Shelving

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Materia l andl ing C lassicsP a p e r s i n t h e c l a s s i c s s e r i e s h a v e a p p e a r e d i n p r e v i o u s p u b l i c a t i o n s o f t h eM a t e r i a l H a n d l i n g I n s t i t u t e a n d a r e a t l e a s t t e n y e a r s o l d . N o n e t h e l e s s t h e i r v a l u ei n c o n t r i b u t i n g t o t h e e v o l u t i o n o f t h e i n d u s t r y a n d t o c u r r e n t p r a c t i c e i s v i e w e dt o b e t i m e l e s s e v e n t h o u g h i n m a n y c a s e s t h e a u t h o r s a n d c o m p a n i e s c r e d i t e d a r en o l o n g e r i n t h e i n d u s t r y .

UNITIZING EQUIPMENT, LIFT TRUCKS,

RACKS AND SHELVING1981 NATIONAL MATERIAL HANDLING FORUM

DAVID L, SCHAEFER

PRESIDENTDAVID L. SCHAEFER, INC.

APRIL 6, 1981

INTRODUCTION

I am here this morning to talk to you about Productivity, In fact, I will be followed by no less

than a dozen other speakers who will also talk to you about Productivity; not Productivity

yesterday, not Productivity in the future, but Productivity Now!

What is Productivity? It is often defined as output per unit of time. Since we pay for time very

dearly and at an ever-increasing rate, if output doesnt keep pace, it costs more for the sameresult. This also happens if output slips and the time cost remains constant.

So when we talk about productivity, were talking about money. The challenge facing is then, is

to attain increased productivity in an economic fashion. Specifically, productivity in materialhandling.

When you hear the term material handling, you are more likely than not to think aboutequipment. Equipment like AS/RS machines with sophisticated computer controls, automated

sorters that look like highway interchanges where you expect an accident is waiting to happen

but happily doesnt, banks of computers at attention barking out orders, equipment that drivesitself without people, loads and unloads itself all at high speed.


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This attitude is understandable. Equipment has been, is, and will continue to be a large part of

the world of material handling. But it is only a part, a tool which, like any tool when usedproperly can make a job easier, and increase productivity.

Material handling is also space, materials, and ultimately, money. It is information, paperwork,and people. It is simple to some, complex to others, and more misunderstood than understood.

It is an art and science; now more an art but fast becoming more like a science, a very complex

science.

One of the keys to improving Productivity Now! is understanding the material handling system.

So before we talk about those types of equipment which are my topic, I would like to present mydefinition of a material handling system to help us put things into perspective.

A MATERIAL HANDLING SYSTEM, is a specific combination of methods, space, labor and

equipment functioning under a unique set of operating condition and objectives, which can beexpressed in economic terms. Lets further examine the components of this definition.

It is these operating conditions and objectives that define a companys material handling

requirements, and it is these material handling requirements that determine the potential methodsthat might be used in a system.

Some of the operating parameters that the material handling system may have to meet and must

be designed to handle if it is to be effective includes:

1) The product line involved2) The number of items in those products3) The inventory levels of items4) The physical characteristics/value of the items5) The customers their number and location6) The number of orders the customers submit7) The size of those orders8) The time to fill the orders9) The number of receipts and shipments to be handled10)The size of the receipts and shipments to be handled, and so on.We often hear that the overall objective of material handling is to have the right materials in theright place at the right time.

In addition, there are other objectives that he material handling system must often function under

and meet. These may include:

1) A high level of customer service2) Lowest cost of operation3) No downtime4) Rapid response time to orders5) A high fill rate on orders6) High accuracy


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7) No damaged goodsThe methods we find in a material handling system can be divided into two main areas:

1) Physical flow2) Information flowPhysical flow is concerned with:

1) How we handle materials2) How we move materials3) How we store materialsInformation flow is concerned with:

1) How we control materialsThe physical flow of goods is accomplished through one or more methods ha may be classified

as:

1) Manual2) Mechanized3) AutomatedThe same applies to information flow although the terminology is different.

The common thread here is that every method of physical flow and every method of information

flow has space, labor, and equipment requirements associated with it, but not to the same degree

in every case. A common fork truck pallet method of storage requires space, it requires labor,

and it requires equipment. So does a sophisticated automated stacker/retriever system. Amanual method of preparing and controlling warehouse-picking orders requires space, it requires

labor, and it requires equipment. So does a sophisticated on-line order entry system. It is the

method that determines the space, labor, and equipment requirements.

With this definition in mind: A Material Handling System is a specific combination of methods,

space, labor and equipment functioning under a unique set of operating conditions and objectiveswhich can be expressed in economic terms: Let us proceed to discuss Unitizing Equipment.

UNITIZING EQUIPMENT

CIC-MHE, The College-Industry Council on Material Handling Education, has formulatedtwenty principles of material handling. The Unit Size Principle is: Increase the quantity, or size

of unit loads of flow rate.

James M. Apple defined a unit load is:


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A number of items, or bulk material, so arranged or restrained that the mass can be picked up

and moved as a single object, too large for manual handling and upon being released will retainits initial arrangement for subsequent movement.

Types of unit load are:a) On a platformb) On a sheetc) On a rackd) In a containere) Self-containedThere are basically three methods of building a unit load:

a) Manualb) Semi-mechanizedc) MechanizedThe manual method consists of one or more operators arranging the materials into a specific

pattern on the floor, on a pallet or on a slip-sheet, depending upon how the load is to be handled.

A lift truck equipped with a push-pull device is used to move and stack slip-sheeted unit loads.

In the semi-mechanized method, manual labor is used to arrange items into a specific pattern for

each layer, and then a palletizer transfers the layer to a pallet and lowers the pallet for the next

layer.

The automatic palletizer does this automatically. An automatic palletizer forms unit loadswithout pallets and transfers the to a conveyor from which they are moved to a stretch wrapping

machine. From there, they are moved to storage by a clamp truck.

Scanners read a bar code printed on each case. The data is fed to a Programmable LogicController (PLC) which controls the entire operation.

As each row of cases is formed in the merge area at the end of the conveyor, it is pushed underthe palletizer vacuum head.

When one layer of a unit is accumulated on the palletizer, a skirted vacuum head lowers andgently secures the entire pattern of cases by vacuum formed inside the skirt.

The vacuum head of the palletizer lifts the cases and carries them to the discharge conveyor.

The palletizer places one layer of cases on top of another until the predetermined unit load isassembled. The load is then discharged.

Please note that regardless of the way we form the unit load, the subsequent means of

transporting the unit load is primary consideration. In fact, when the load is self-contained we

might say that the transporting device is the unitizing element as well. For example:


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1) Rolls of carpets are handled with a ram attachment.2) 55-gallon drums are handled individually with a drum grab.3) Large appliances like refrigerators or freezers are handle individually with a device that picks

up a specifically designed carton at the top.

4) Large rolls of paper are handled with a paper roll.5) Bales are handled with a bale clamp.In addition to building unit loads, we are often faced with the necessity of securing the load forsafe handling. Many items that must be handled are irregular in shape, bulky, or fragile and if

they are not secured result in lower productivity, increased handling and storage costs, and

damaged, often-unusable goods.

The most common methods of securing unit loads include:

a) Steel or plastic strap the strap may be applied either manually and tightened with ahandheld crimper or by machine, either off-line or for smaller loads with a strapping machine

mounted in-line with a conveyor.

b) Adhesives these are applied directly to the items constituting the unit load and give itstability.

c) Shrink or stretch wrap A pliable plastic film is placed around the unit load conforming toits outline and securing it. Basic application methods include moving the film around thestationary load and manually or automatically or having the load rotate and pick up the film.

In summary then, unitizing equipment consists of pallets, slip-sheets and containers to hold the

unit load, semi-automatic and fully automatic palletizers to form the unit load, various lift truckattachments to move self-contained unit loads, and stretch wrappers to secure unit loads forhandling and storage.

The proper selection and application of unitizing equipment in your own operation will help you

to achieve increased Productivity Now!

LIFT TRUCKS

CIC-MHEs 8th

principle of material handling is the Mechanization Principle. It simply states

Mechanize Handling Operations.

One of the most basic ways to mechanize handling operations is to use lift trucks. Lift trucks

consist of several types under the broader heading of industrial trucks.

Apple defines a Fork Lift Truck as: A self-loading, counterbalanced, self-propelled wheeled

vehicle, carrying an operator and designed to carry a load on a fork or other attachment fastenedto a telescoping mast which is mounted ahead of the vehicle to permit lifting and stacking of

loads.

Gasoline, diesel, battery, or LP gas may power these trucks.

The operator may ride in the center or at the back end of the truck and he may sit or stand.


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The trucks may be operated on any type of floor, wood, concrete, highway, or yard, with theproper wheels and tires.

Forklift Trucks are basically used for lifting and lowering, stacking and unstacking, and loadingand unloading of medium to large size uniformly shaped unit loads.

The volume of material handled is in the low to medium range, and the trucks moveintermittently

Lets look at various types of forklift trucks.

There is a sit down rider counterbalanced forklift truck, battery powered with a capacity of 3,500

lbs.

A recent innovation in counterbalance trucks is 3 wheels instead of 4. This feature makes the

truck highly maneuverable in tight corners.

This same truck can stack to considerable height and also fits inside an over-the-road trailer.

Very large loads in the range of 11,00 to 16,500 pounds are handled by this sit down ridercounterbalanced forklift truck, with diesel engines.

The second largest class of lift trucks consists of what are commonly referred to as narrow aisle

trucks. These are lowered trucks capable of operating in aisles ranging from 6 feet down to 30inches wide because of their design features.

The oldest type of narrow aisle truck is the straddle or outrigger type. The outriggers or straddle

arms straddle the load and perform the function of a counterbalance. As with all narrow aisle

trucks, the straddle truck id highly maneuverable, lighter in weight than counterbalanced trucksof equal capacity, battery powered and uses less aisle space than non-narrow aisle trucks.

A variation of the straddle truck is the narrow aisle truck. The truck is equipped with apantograph device, which reaches out to pick up or deposit the load. The pantograph is retracted

to the mast for traveling.

Another type of narrow aisle truck is the order picking truck. The truck is equipped with a

pantograph device, which reaches out to pick up or deposit the load. The pantograph is retracted

to the mast for travelling.

Another type of narrow aisle truck is the order picking truck. The operator rides on a platform,which he elevates or lowers as required to pick orders.

Other narrow aisle trucks include:


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a) Side loaders which as the name implies pick up and deposit their loads with the mast andfork is perpendicular to the truck chassis. Especially useful for long loads such as pipe,lumber, steel rods, and bar stock.

b) Turret trucks where the forks are capable of rotating pallet loads up to a full 180 degreeswithin an aisle as narrow as 24 wider than the load.

All of the trucks weve discussed to this point have had the operator riding on the truck itself. If

we keep the truck power-propelled and power0operated but with the operator walking andoperating the truck by means of controls on the handle we have a walkie.

We have a walkie pallet truck, a walkie stacker, narrow aisle, note the straddles, and a walkiereach.

Not all walkies are pure walkies.

There is an end-control walkie rider pallet truck.

As our operator gets lazy, he and the truck evolve into a rider pallet truck. Last, but not least, is

the most versatile, lest costly to operate from a fuel point of view, and the one the boss tells us tobuy when we ask for a turret-truck, the venerable hand pallet truck!

RACKS AND SHELVING

CIC-MHEs 6th

principle is the space utilization principle. It states: Make optimum utilization ofbuilding cube.

This statement implies that we must store material as efficiently as possible consistent with

economic and other constraints.

There are two basic types of storage equipment that can be used to accomplish this. They are

storage racks and shelving.

Storage rack is a framework of vertical upright frames and horizontal beams, and /or load rails or

arms designed to accept and store palletized, containerized, or large unit loads placed thereon bymechanized handling equipment, such as fork lift trucks, automatic controlled mechanical

storage equipment or other types of lifting mechanisms.

The Rack Manufacturers Institute has graciously lent me their slide presentation on racks and

they can say it better than I can.

Steel Shelving is a storage system designed to accept and store unpalletized loads, placedthereon, either manually or by automated retrieval mechanism.


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These are basic sections of steel shelving, easily accessible from floor and used to store a variety

of unpalletized materials.

Mezzanines are often added to further utilize cube effectively.

It is also not uncommon to see conveyor and shelving used together in order picking operations.

This combination results in high levels of Productivity Now!

utilizing equipment, lift trucks, racks and shelving

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