Lesson 16
Distribution Packaging
第 16课 运输包装
Short History of Distribution Packaging in the USA
Distribution packaging emerged in the 1800s as the industrial
revolution blossomed and manufacturers began shipping their goods
nationwide via railroad,
- Paper did not enter the distribution arena as protective packaging
until the early 1900s,when corrugated boxes first appeared as
shipping containers,
- From the end of World War I to the end of World War II,the use
ratio of corrugated to wood containers went from 20/80 to 80/20,
- Pallets became popular for industrial use following World War II,
and unitizing of high-volume products for shipment accelerated in
the 1950s,
- Plastics began appearing in the early 1960s with various foams
replacing corrugated,rubberized fiber,and wood-based products as
interior packaging,
Functions and Goals of Distribution Packaging
The functions of distribution packaging can be summarized as
follows,
Containment
Protection
Performance
Communication
- Most distribution packaging should address the following goals,
Product protection,
Ease of handling and storage
Shipping effectiveness
Manufacturing efficiency,
Ease of identification
Customer needs
Environmental responsibility
The Cost of Packaging
It was estimated that expenditures for all packaging materials,
including expendable (one-way) shipping pallets,were
approximately $100 billion in 1997,Of this total,about one-third was
in the form of distribution packaging,
- The largest single segment of distribution packaging is corrugated
shipping containers,at approximately 20% of total expenditures and
60% of distribution packaging costs,
- It has been estimated that although actual freight claims paid by
carriers for damaging goods is approximately $2 billion,the actual
cost to them and to shippers is really more than $10 billion per year,
- Our goal in package design is to minimize the cost of both
packaging and damage,
The Package Design Process
To develop an optimum distribution package that is both
functional and cost-effective,you will need more than just
assistance from your packaging suppliers,
- Although your experience with a product line and a supplier's
experience with packaging materials are both helpful in designing
packaging,both of you should consider many factors in addition to
the product and the packaging,
- Your scope of consideration should include all aspects of the
distribution system,including customers,carriers,and distributors,
as well as the manufacturing plant,packaging line,warehousing,
and shipping,To be successful in distribution package design,take a
total-system approach,
Taking a Total System Approach to Package Design
Once created,a package has an influence on and is influenced by
everyone and everything it encounters,
-Most of these encounters affect manufacturing and distribution
costs or product integrity,with indirect impact on sales,
- A general rule of thumb is that the total cost of transportation is
between 3 and 10 times as much as packaging on average for all
shipments,A small reduction in package size or weight could mean
substantial savings in transportation costs,as well as in handling
and storage,
- An inverse relationship exists between packaging cost and
maintaining product integrity with low damage rates,as shown in
Figure 14.1,An increase in packaging costs provides more
protection to the contents and therefore lowers the potential for
damage,
Taking a Total System Approach to Package Design
Figure 16.1 The optimum packaging system balances costs
from excessive damagewith the costs of overpackaging
Taking a Total System Approach to Package Design
The real cost of getting the product safely to market is the sum of
packaging and damage,
- Optimizing total cost is the true goal of packaging design,
- No matter where in the company your packaging design function is
located,in engineering,manufacturing,shipping,or elsewhere,try to
include all factors in a total-system approach for an optimum design,
The Protective Package Concept
Product + Package = Distribution environment
Figure 16.2 depicts the consequences of an imbalance in this
equation,showing what happens when a product plus its package
are not exactly what is needed to survive in the distribution process,
Taking a Total System Approach to Package Design
Figure 16.2 Protective package concept
Taking a Total System Approach to Package Design
Severity is the quantitative measure of the environment,which can
be anyone or a combination of hazards in distribution,
hazards severity
the rough-handling hazard to 30 inches of drop
a 20-pound package
the compression (storage) hazard 10 packages high in warehousing
the high temperature hazard 1300 F,
Product represents the measured level of resistance to damage of
the product,
- An optimum solution,the product's measured level of damage
resistance plus the packaging's measured abilities to protect the
product are exactly equal to the expected environmental hazard(s)
Taking a Total System Approach to Package Design
For example,a product with 15-inch drop resistance is packaged in
material that will dissipate the shock generated in the 30 inches of
drop height the packaged product is expected to encounter in the
distribution environment,
- When the package provides less protective capacity than
needed for the environment,this underpackaging will result in
damage,
- Overpackaging,The package protection level is higher than the
environment requires,
- It may be possible to improve the product as an alternative to
more packaging,
- The most elusive part of the package-plus-product equation is
the distribution environment,
The 10-Step Process of Distribution Packaging Design
A 10-step procedure will help you design a distribution package that
provides maximum performance at least overall cost,
1,Identify the Physical Characteristics of the Product
2,Determine Marketing and Distribution Requirements
3,Learn about the Environmental Hazards Your Packages Will
Encounter
4,Consider Packaging and Unitizing Alternatives
5,Design the Distribution package
6,Determine Quality of Protection through Performance-Testing
7,Redesign Package (and Unit Load) until It Successfully
Passes All Tests
8,Redesign the Product if Indicated and Feasible
9,Develop the Packaging Methods
10,Document All Work
A Final Check
Here is another suggestion,For any package design
project,after completing the 10-step procedure above,
check your work against the list of important
considerations as follows,By doing so you will
significantly reduce the potential for an unpleasant
surprise when shipments begin,
Package Design Project Checklist
Have you,
1,Considered the solid waste aspects of the package
and unit load,and their alternatives,to minimize impact
on the environment?
A Final Check
2,Pondered the use of returnable/reusable containers and dunnage?
3,Contemplated all cost factors in the distribution cycle,handling,
storage,transportation?
4,Compared the cost of this package with company/plant averages
for similar products?
5,Considered all possible alternatives in materials and methods?
6,Used industry standards for materials and design criteria where
possible?
7,Performance-tested the design against accepted industry
standards?
8,Documented the design using the company's specification system?
9,Checked damage and customer complaints on this product line?
10,Satisfied all rules and regulations applying to this product for all
distribution modes it is expected to encounter?
The Warehouse
The distribution warehouse is a central collecting point for a
particular good or a particular merchandising chain,Finished goods
are forwarded to and held at the warehouse until selected and
assembled into a customer order,The warehouse environment is not
well understood by many shippers,
A typical dry groceries warehouse may contain 20,000
individual stock items,A hardware chain warehouse holds upwards
of 40,000 stock items,Product arrives at the central warehouse in
bulk or unitized,is broken down or reunitized according to the
warehouse's needs,and then is arranged for stock-picking,Stock-
picking is the process of selecting individual items to fill an order for
a particular store or destination,Central warehouses serve large
customer areas; in some instances one or two warehouses may
essentially serve the entire nation,
The Warehouse
A product must fit the warehouse's material handling system,This
often means palleting loose loads or repalleting loads from
nonstandard pallets,Depending on the operation,anywhere from 33
to 70% of product received at a warehouse must be handled
manually before an order is placed in stock,Manual handling,in
addition to being costly,is also a primary source of damage from
dropping,
In the picking aisles,stock must be clearly identifiable from every
side,Multicolor graphic displays serve only to obscure vital
information from the picker,A box labeled "Golden Triangle Farms"
does not inform the stock-picker of the contents,Containers should
be strong enough to be dragged off the pallet by one end,and stiff
enough that they don't distort and release their contents when
handled in less than ideal fashion,Glue flaps must have enough
adhesive to resist abusive handling,
The Warehouse
An assembled order may contain items as disparate as eight
mirrors,six assorted clocks,a case of oil,four shock absorbers,a
stepladder,and a Mepps #4 fishing lure,These and other items are
assembled on a mixed pallet for transport to the retail outlet,
Containers must be easily handled by the picker and should be
readily packed onto a mixed-order pallet,Container orientation on
mixed-load pallets will tend to be on a "best fit" basis,regardless of
"This side up" and "Do not stack" labels,It may be possible to pack a
trapezoidal container efficiently on your pallet,but odd shapes do not
pack well in a mixed-product pallet load,Use boxes with a
rectangular cross section wherever possible,
Unit Loads
Pallets
It is simpler to move one 1,000-kilogram load than it is
to move a thousand 1- kilogram loads,Loads are most
commonly unitized on pallets,a platform that can be
picked up by the tines of a forklift truck,Another technique uses slip
sheets,tough fiberboard or plastic sheets on which the load is
stacked,The truck used with slip sheets has a clamp mechanism
that grasps a protruding edge of the sheet and pulls the sheet and
load onto a platform attached to the truck,A third method of handling
a large group of assembled objects is with a clamp truck,a
mechanism that picks up loads by exerting pressure from both sides
of the load,
Unit Loads
Each method has its advantages and disadvantages,Slip sheets
are economical,take up little space,and are light,However,the
equipment is not universally available,is more expensive,and is
slower to operate,Pallets are universally adaptable to a variety of
handling situations and locations,However,pallets are costly,take
up space,and can be difficult to dispose of,Clamp trucks use no
added materials,but the geometry and character of the load must be
such that it can be squeezed between the truck's clamps,
Most pallets are made of wood,and choice of wood species has a
great impact on cost and durability,The denser and stiffer the wood,
the greater the pallet's durability and usually the greater its cost,
Well-made hardwood pallets are the most durable and cost-effective
option of the many material choices available,Other materials are
usually selected for considerations other than durability,
Unit Loads
There are many possible pallet sizes and designs;
however,for the sake of standardized distribution,certain
sizes and designs predominate,By convention,a pallet's
size is stated length first,with length defined as the top
dimension along the stringer or stringer board ( Figure
16.3),About a third of all pallets are nominally 40 by 48
inches,the standard set by members of the Grocery
Manufacturers of America,This size is also very close to
the international 1,000 by 1,200 mm size,
The two broad categories of pallet design are stringer
and block types (Figure 16.3),A range of variations is
available within each design type,
Unit Loads
Figure 16.3 A block pallet(left) and a stringer-type pallet(right)
Unit Loads
Reversible pallets have similar top and bottom decks,
Nonreversible designs have different top and bottom decks,with
only the top deck designed to be a load-carrying platform,
· Wing pallets have the stringers inset so that the deck boards
overhang,This allows for the pallets to be handled by slings,Pallets
can be single wing or double wing,depending on whether one or
both decks overhang the stringers,
·Two-way-entry pallets have solid stringers and can be entered
only from the two ends,
· Block-type pallets are four-way entry,since any equipment can
enter the pallet from all four directions,A partial four-way has
notches cut into the stringer bottoms,A forklift's tines can enter from
any direction,but a hand truck can only enter from two directions,
Unit Loads
In addition to providing a product platform,the pallet is a buffer
against the handling environment,A forklift driver placing a pallet
into position cannot see the exact placement location,he stops when
he hits something,
Viewed in this context,practices such as deliberate pallet
perimeter overhang can only lead to problems,and warehouse
operators condemn this habit,The Food Marketing Institute holds
pallet issues responsible for about half of all observed damage and
cites poor pallet footprint as the single largest cause of shipping
damage,Of this damage,50% is attributed to poor pallet stability
and 35% is attributed to pallet overhang,
Pallet maintenance programs are essential,A common and easily
remedied problem is fasteners working their way out of the wood,
Unit Loads
Unit Load Efficiency
Warehouse floor space is rented by area,and the more product
that can be put into that area,the better,Trucks loaded with light
product should have the available volume completely filled to carry
the maximum amount of product per trip,Area and cube utilization
should be every packager's concern,
Optimum area and cube utilization begins with the design of the
primary package,Primary dimensions should be considered in terms
of possible packing orientations in the shipping container,impact on
corrugated board use in the shipping container,and palleting pattern
and space utilization,
Unit Loads
,Arrangement” refers to packing patterns used when placing
primary packages into a shipper,Traditionally,the problem was
solved through intuition,experience,and a few nominal calculations,
However,small cartons,packed 24 to a shipper,may have over a
thousand possible orientation and palleting solutions,Computer
"arrangement" programs are available that will calculate all the
implications of size decisions in minutes,Typical input data for a
palleting-efficiency computer program are,
· Data pertaining to the primary container
· Allowed primary design changes,if required
· Data pertaining to the proposed shipping case
· Data pertaining to palleting requirements
Unit Loads
Typical output data for such a program might provide the following
information,
· Optimum dimensions for the primary container
· Optimum packing orientations for selected primary containers
· Inside and outside case dimensions for each selected case type
·Number of units per pallet for each primary/case option
·Area and cube utilization for each primary/case option
· Recommended pallet patterns,including "walk-around" views
·Dimensional details of the pallet pattern
· Material areas used in primary,divider,and case construction
·Relative cost factors for each construction
·Relative compression values for corrugated board constructions
·Proposed maximum warehouse stacking heights
Unit Loads
A thorough system analysis (including losses) can lead
to substantial savings,A major business equipment
manufacturer found that it had poor shipping experience
because of the hundreds of different package sizes in the
product line,The company designed a modular system,
and all products were designed to fit one of 17 standard
box sizes,Besides significant inventory reduction,the
company gained substantial transport savings,since
larger,more stable pallet loads could be built with the
modular system,More-secure pallet loads resulted in
further savings through reduced product damage,
Unit Loads
Stabilizing Unit Loads
Unit loads often need to be stabilized in order to retain load
geometry and order during shipping and handling,Strapping is used
mostly for heavier goods,Care must be taken that strapping does
not cut into the corrugated container,impairing strength qualities,
Cord is sometimes used as a more economical alternative,also
causing cut-in problems,Corner guards should be used to prevent
cut-in where strapping or cord is the necessary choice,Shrink-
wrapping is rarely used for load unitizing due to high installation
and energy costs,Today's material of choice is stretch-wrapping,A
good stretch-wrap application consists of two overlapped wraps
extending 50 mm down the pallet to bind the load to the pallet,The
wraps should overlap about 40% up the pallet side,Three
overlapping wraps extending 50 mm past the top of the load finish
the pallet,
Unit Loads
Hand-wrapping a pallet with stretch material costs about $1.40,
Machine-wrapping provides better material control and typically
reduces the cost to about $1.00,Machines with prestretch features
reduce this cost still further,More costly open netting is used where
air circulation is essential,
Load stability can be increased through the use of high-friction
printing inks and coatings or by the application of adhesive-like
compounds,Adhesives can be designed to produce a high-tack local
bond,One variation is the use of a bead of hot-melt adhesive
formulated to have relatively poor cohesive strength,The bead forms
a readily sheared bond between two box surfaces,However,
systems that bond boxes together have caused handling problems
and are not a popular load-stabilizing method with some warehouses,
Unit Loads
Caps and trays made of fiberboard or corrugated board are used to
provide shape to unstable loads,to provide bottom protection
against rough pallet surfaces,and,when used on top of a load,to
increase the platform quality for the next pallet,Tier sheets improve
available compression strength and increase stability by distributing
weight and encouraging layers to act as a unit,
Distribution Packaging
第 16课 运输包装
Short History of Distribution Packaging in the USA
Distribution packaging emerged in the 1800s as the industrial
revolution blossomed and manufacturers began shipping their goods
nationwide via railroad,
- Paper did not enter the distribution arena as protective packaging
until the early 1900s,when corrugated boxes first appeared as
shipping containers,
- From the end of World War I to the end of World War II,the use
ratio of corrugated to wood containers went from 20/80 to 80/20,
- Pallets became popular for industrial use following World War II,
and unitizing of high-volume products for shipment accelerated in
the 1950s,
- Plastics began appearing in the early 1960s with various foams
replacing corrugated,rubberized fiber,and wood-based products as
interior packaging,
Functions and Goals of Distribution Packaging
The functions of distribution packaging can be summarized as
follows,
Containment
Protection
Performance
Communication
- Most distribution packaging should address the following goals,
Product protection,
Ease of handling and storage
Shipping effectiveness
Manufacturing efficiency,
Ease of identification
Customer needs
Environmental responsibility
The Cost of Packaging
It was estimated that expenditures for all packaging materials,
including expendable (one-way) shipping pallets,were
approximately $100 billion in 1997,Of this total,about one-third was
in the form of distribution packaging,
- The largest single segment of distribution packaging is corrugated
shipping containers,at approximately 20% of total expenditures and
60% of distribution packaging costs,
- It has been estimated that although actual freight claims paid by
carriers for damaging goods is approximately $2 billion,the actual
cost to them and to shippers is really more than $10 billion per year,
- Our goal in package design is to minimize the cost of both
packaging and damage,
The Package Design Process
To develop an optimum distribution package that is both
functional and cost-effective,you will need more than just
assistance from your packaging suppliers,
- Although your experience with a product line and a supplier's
experience with packaging materials are both helpful in designing
packaging,both of you should consider many factors in addition to
the product and the packaging,
- Your scope of consideration should include all aspects of the
distribution system,including customers,carriers,and distributors,
as well as the manufacturing plant,packaging line,warehousing,
and shipping,To be successful in distribution package design,take a
total-system approach,
Taking a Total System Approach to Package Design
Once created,a package has an influence on and is influenced by
everyone and everything it encounters,
-Most of these encounters affect manufacturing and distribution
costs or product integrity,with indirect impact on sales,
- A general rule of thumb is that the total cost of transportation is
between 3 and 10 times as much as packaging on average for all
shipments,A small reduction in package size or weight could mean
substantial savings in transportation costs,as well as in handling
and storage,
- An inverse relationship exists between packaging cost and
maintaining product integrity with low damage rates,as shown in
Figure 14.1,An increase in packaging costs provides more
protection to the contents and therefore lowers the potential for
damage,
Taking a Total System Approach to Package Design
Figure 16.1 The optimum packaging system balances costs
from excessive damagewith the costs of overpackaging
Taking a Total System Approach to Package Design
The real cost of getting the product safely to market is the sum of
packaging and damage,
- Optimizing total cost is the true goal of packaging design,
- No matter where in the company your packaging design function is
located,in engineering,manufacturing,shipping,or elsewhere,try to
include all factors in a total-system approach for an optimum design,
The Protective Package Concept
Product + Package = Distribution environment
Figure 16.2 depicts the consequences of an imbalance in this
equation,showing what happens when a product plus its package
are not exactly what is needed to survive in the distribution process,
Taking a Total System Approach to Package Design
Figure 16.2 Protective package concept
Taking a Total System Approach to Package Design
Severity is the quantitative measure of the environment,which can
be anyone or a combination of hazards in distribution,
hazards severity
the rough-handling hazard to 30 inches of drop
a 20-pound package
the compression (storage) hazard 10 packages high in warehousing
the high temperature hazard 1300 F,
Product represents the measured level of resistance to damage of
the product,
- An optimum solution,the product's measured level of damage
resistance plus the packaging's measured abilities to protect the
product are exactly equal to the expected environmental hazard(s)
Taking a Total System Approach to Package Design
For example,a product with 15-inch drop resistance is packaged in
material that will dissipate the shock generated in the 30 inches of
drop height the packaged product is expected to encounter in the
distribution environment,
- When the package provides less protective capacity than
needed for the environment,this underpackaging will result in
damage,
- Overpackaging,The package protection level is higher than the
environment requires,
- It may be possible to improve the product as an alternative to
more packaging,
- The most elusive part of the package-plus-product equation is
the distribution environment,
The 10-Step Process of Distribution Packaging Design
A 10-step procedure will help you design a distribution package that
provides maximum performance at least overall cost,
1,Identify the Physical Characteristics of the Product
2,Determine Marketing and Distribution Requirements
3,Learn about the Environmental Hazards Your Packages Will
Encounter
4,Consider Packaging and Unitizing Alternatives
5,Design the Distribution package
6,Determine Quality of Protection through Performance-Testing
7,Redesign Package (and Unit Load) until It Successfully
Passes All Tests
8,Redesign the Product if Indicated and Feasible
9,Develop the Packaging Methods
10,Document All Work
A Final Check
Here is another suggestion,For any package design
project,after completing the 10-step procedure above,
check your work against the list of important
considerations as follows,By doing so you will
significantly reduce the potential for an unpleasant
surprise when shipments begin,
Package Design Project Checklist
Have you,
1,Considered the solid waste aspects of the package
and unit load,and their alternatives,to minimize impact
on the environment?
A Final Check
2,Pondered the use of returnable/reusable containers and dunnage?
3,Contemplated all cost factors in the distribution cycle,handling,
storage,transportation?
4,Compared the cost of this package with company/plant averages
for similar products?
5,Considered all possible alternatives in materials and methods?
6,Used industry standards for materials and design criteria where
possible?
7,Performance-tested the design against accepted industry
standards?
8,Documented the design using the company's specification system?
9,Checked damage and customer complaints on this product line?
10,Satisfied all rules and regulations applying to this product for all
distribution modes it is expected to encounter?
The Warehouse
The distribution warehouse is a central collecting point for a
particular good or a particular merchandising chain,Finished goods
are forwarded to and held at the warehouse until selected and
assembled into a customer order,The warehouse environment is not
well understood by many shippers,
A typical dry groceries warehouse may contain 20,000
individual stock items,A hardware chain warehouse holds upwards
of 40,000 stock items,Product arrives at the central warehouse in
bulk or unitized,is broken down or reunitized according to the
warehouse's needs,and then is arranged for stock-picking,Stock-
picking is the process of selecting individual items to fill an order for
a particular store or destination,Central warehouses serve large
customer areas; in some instances one or two warehouses may
essentially serve the entire nation,
The Warehouse
A product must fit the warehouse's material handling system,This
often means palleting loose loads or repalleting loads from
nonstandard pallets,Depending on the operation,anywhere from 33
to 70% of product received at a warehouse must be handled
manually before an order is placed in stock,Manual handling,in
addition to being costly,is also a primary source of damage from
dropping,
In the picking aisles,stock must be clearly identifiable from every
side,Multicolor graphic displays serve only to obscure vital
information from the picker,A box labeled "Golden Triangle Farms"
does not inform the stock-picker of the contents,Containers should
be strong enough to be dragged off the pallet by one end,and stiff
enough that they don't distort and release their contents when
handled in less than ideal fashion,Glue flaps must have enough
adhesive to resist abusive handling,
The Warehouse
An assembled order may contain items as disparate as eight
mirrors,six assorted clocks,a case of oil,four shock absorbers,a
stepladder,and a Mepps #4 fishing lure,These and other items are
assembled on a mixed pallet for transport to the retail outlet,
Containers must be easily handled by the picker and should be
readily packed onto a mixed-order pallet,Container orientation on
mixed-load pallets will tend to be on a "best fit" basis,regardless of
"This side up" and "Do not stack" labels,It may be possible to pack a
trapezoidal container efficiently on your pallet,but odd shapes do not
pack well in a mixed-product pallet load,Use boxes with a
rectangular cross section wherever possible,
Unit Loads
Pallets
It is simpler to move one 1,000-kilogram load than it is
to move a thousand 1- kilogram loads,Loads are most
commonly unitized on pallets,a platform that can be
picked up by the tines of a forklift truck,Another technique uses slip
sheets,tough fiberboard or plastic sheets on which the load is
stacked,The truck used with slip sheets has a clamp mechanism
that grasps a protruding edge of the sheet and pulls the sheet and
load onto a platform attached to the truck,A third method of handling
a large group of assembled objects is with a clamp truck,a
mechanism that picks up loads by exerting pressure from both sides
of the load,
Unit Loads
Each method has its advantages and disadvantages,Slip sheets
are economical,take up little space,and are light,However,the
equipment is not universally available,is more expensive,and is
slower to operate,Pallets are universally adaptable to a variety of
handling situations and locations,However,pallets are costly,take
up space,and can be difficult to dispose of,Clamp trucks use no
added materials,but the geometry and character of the load must be
such that it can be squeezed between the truck's clamps,
Most pallets are made of wood,and choice of wood species has a
great impact on cost and durability,The denser and stiffer the wood,
the greater the pallet's durability and usually the greater its cost,
Well-made hardwood pallets are the most durable and cost-effective
option of the many material choices available,Other materials are
usually selected for considerations other than durability,
Unit Loads
There are many possible pallet sizes and designs;
however,for the sake of standardized distribution,certain
sizes and designs predominate,By convention,a pallet's
size is stated length first,with length defined as the top
dimension along the stringer or stringer board ( Figure
16.3),About a third of all pallets are nominally 40 by 48
inches,the standard set by members of the Grocery
Manufacturers of America,This size is also very close to
the international 1,000 by 1,200 mm size,
The two broad categories of pallet design are stringer
and block types (Figure 16.3),A range of variations is
available within each design type,
Unit Loads
Figure 16.3 A block pallet(left) and a stringer-type pallet(right)
Unit Loads
Reversible pallets have similar top and bottom decks,
Nonreversible designs have different top and bottom decks,with
only the top deck designed to be a load-carrying platform,
· Wing pallets have the stringers inset so that the deck boards
overhang,This allows for the pallets to be handled by slings,Pallets
can be single wing or double wing,depending on whether one or
both decks overhang the stringers,
·Two-way-entry pallets have solid stringers and can be entered
only from the two ends,
· Block-type pallets are four-way entry,since any equipment can
enter the pallet from all four directions,A partial four-way has
notches cut into the stringer bottoms,A forklift's tines can enter from
any direction,but a hand truck can only enter from two directions,
Unit Loads
In addition to providing a product platform,the pallet is a buffer
against the handling environment,A forklift driver placing a pallet
into position cannot see the exact placement location,he stops when
he hits something,
Viewed in this context,practices such as deliberate pallet
perimeter overhang can only lead to problems,and warehouse
operators condemn this habit,The Food Marketing Institute holds
pallet issues responsible for about half of all observed damage and
cites poor pallet footprint as the single largest cause of shipping
damage,Of this damage,50% is attributed to poor pallet stability
and 35% is attributed to pallet overhang,
Pallet maintenance programs are essential,A common and easily
remedied problem is fasteners working their way out of the wood,
Unit Loads
Unit Load Efficiency
Warehouse floor space is rented by area,and the more product
that can be put into that area,the better,Trucks loaded with light
product should have the available volume completely filled to carry
the maximum amount of product per trip,Area and cube utilization
should be every packager's concern,
Optimum area and cube utilization begins with the design of the
primary package,Primary dimensions should be considered in terms
of possible packing orientations in the shipping container,impact on
corrugated board use in the shipping container,and palleting pattern
and space utilization,
Unit Loads
,Arrangement” refers to packing patterns used when placing
primary packages into a shipper,Traditionally,the problem was
solved through intuition,experience,and a few nominal calculations,
However,small cartons,packed 24 to a shipper,may have over a
thousand possible orientation and palleting solutions,Computer
"arrangement" programs are available that will calculate all the
implications of size decisions in minutes,Typical input data for a
palleting-efficiency computer program are,
· Data pertaining to the primary container
· Allowed primary design changes,if required
· Data pertaining to the proposed shipping case
· Data pertaining to palleting requirements
Unit Loads
Typical output data for such a program might provide the following
information,
· Optimum dimensions for the primary container
· Optimum packing orientations for selected primary containers
· Inside and outside case dimensions for each selected case type
·Number of units per pallet for each primary/case option
·Area and cube utilization for each primary/case option
· Recommended pallet patterns,including "walk-around" views
·Dimensional details of the pallet pattern
· Material areas used in primary,divider,and case construction
·Relative cost factors for each construction
·Relative compression values for corrugated board constructions
·Proposed maximum warehouse stacking heights
Unit Loads
A thorough system analysis (including losses) can lead
to substantial savings,A major business equipment
manufacturer found that it had poor shipping experience
because of the hundreds of different package sizes in the
product line,The company designed a modular system,
and all products were designed to fit one of 17 standard
box sizes,Besides significant inventory reduction,the
company gained substantial transport savings,since
larger,more stable pallet loads could be built with the
modular system,More-secure pallet loads resulted in
further savings through reduced product damage,
Unit Loads
Stabilizing Unit Loads
Unit loads often need to be stabilized in order to retain load
geometry and order during shipping and handling,Strapping is used
mostly for heavier goods,Care must be taken that strapping does
not cut into the corrugated container,impairing strength qualities,
Cord is sometimes used as a more economical alternative,also
causing cut-in problems,Corner guards should be used to prevent
cut-in where strapping or cord is the necessary choice,Shrink-
wrapping is rarely used for load unitizing due to high installation
and energy costs,Today's material of choice is stretch-wrapping,A
good stretch-wrap application consists of two overlapped wraps
extending 50 mm down the pallet to bind the load to the pallet,The
wraps should overlap about 40% up the pallet side,Three
overlapping wraps extending 50 mm past the top of the load finish
the pallet,
Unit Loads
Hand-wrapping a pallet with stretch material costs about $1.40,
Machine-wrapping provides better material control and typically
reduces the cost to about $1.00,Machines with prestretch features
reduce this cost still further,More costly open netting is used where
air circulation is essential,
Load stability can be increased through the use of high-friction
printing inks and coatings or by the application of adhesive-like
compounds,Adhesives can be designed to produce a high-tack local
bond,One variation is the use of a bead of hot-melt adhesive
formulated to have relatively poor cohesive strength,The bead forms
a readily sheared bond between two box surfaces,However,
systems that bond boxes together have caused handling problems
and are not a popular load-stabilizing method with some warehouses,
Unit Loads
Caps and trays made of fiberboard or corrugated board are used to
provide shape to unstable loads,to provide bottom protection
against rough pallet surfaces,and,when used on top of a load,to
increase the platform quality for the next pallet,Tier sheets improve
available compression strength and increase stability by distributing
weight and encouraging layers to act as a unit,
