Materials Handling, Packaging and Unitisation

Introduction and context

Materials handling concerns the movement, protection, storage, positioning and control of materials throughout a logistics system. It includes activities within receiving areas, warehouses, production facilities, distribution centres, retail outlets and transport interfaces. Packaging and unitisation support these activities by protecting products, consolidating individual items into manageable loads and improving the efficiency of storage and transport.

Materials handling is not simply a question of selecting forklifts or conveyors. It is a systems decision involving product characteristics, facility layout, labour, information, safety, cost, service requirements, regulatory obligations and environmental effects. A poor handling decision can cause product damage, worker injury, excessive space consumption, loading delays and unnecessary carbon emissions. A well-designed system creates a controlled flow in which products move the required distance, in the required condition, with minimum handling and appropriate use of resources.

The central principle is that handling should add as little physical movement as possible while maintaining safety, quality and customer service. This requires coordination between packaging design, pallet patterns, storage equipment, vehicles, dock dimensions, warehouse information systems and operating procedures.

Learning objectives

By the end of this chapter, the learner should be able to:

1. Explain the role and principles of materials handling in logistics systems.
2. Classify handling equipment and select suitable equipment for different products and flows.
3. Evaluate packaging materials and packaging systems using protection, cost, ergonomics, compliance and sustainability criteria.
4. Explain pallets, containers, unit loads and cube utilisation.
5. Calculate basic handling, space-utilisation and unit-load measures.
6. Design a practical unitisation approach for a distribution operation.
7. Assess risks, limitations and governance issues associated with handling and packaging decisions.

1. Materials-handling systems

A materials-handling system comprises the equipment, people, procedures, information and infrastructure used to move and store materials. Its major functions are:

• receiving and unloading;
• inspection and identification;
• put-away and storage;
• order picking and consolidation;
• internal transport;
• loading and dispatch;
• protection against damage, contamination and loss;
• control and traceability.

Handling may be horizontal, vertical, continuous, intermittent, manual, mechanised or automated. The correct choice depends on the nature of the flow rather than on the apparent sophistication of the technology.

Guiding principles

Several established principles support professional design:

Systems principle. Handling should be designed as part of the total logistics system. A fast conveyor may be inappropriate if it creates congestion at picking or dispatch.

Simplification principle. Eliminate unnecessary transfers, repacking, double handling and complicated routes.

Gravity principle. Where safe and practical, gravity can support movement through chutes, gravity-flow racks and sloped conveyors. Gravity systems nevertheless require controls to prevent uncontrolled acceleration and collisions.

Unit-load principle. Materials should be moved in stable, standardised loads rather than as isolated items whenever product and process conditions permit.

Space-utilisation principle. Use available cubic space effectively, while preserving access, ventilation, fire protection and safe operating clearances.

Ergonomic principle. Design work to fit human capabilities. Repetitive lifting, awkward reaches, excessive force and unstable loads increase injury risk and reduce productivity.

Energy and environmental principle. Consider energy consumption, packaging waste, repairability, reuse, recycling and emissions over the product and equipment life cycle.

Flexibility principle. Equipment should accommodate realistic variation in product dimensions, demand, seasonality and future operating requirements.

Maintenance principle. Reliability, inspection access, spare parts and operator training are part of the initial design decision, not afterthoughts.

2. Product and process characteristics

Equipment and packaging must be matched to the product. Important characteristics include:

The process must also be understood. A stable, high-volume flow between fixed points may justify a conveyor or automated guided vehicle. A low-volume operation with many destinations may be better served by pallet trucks, reach trucks or flexible carts. Selection based only on purchase price commonly produces poor total cost performance.

3. Categories of materials-handling equipment

Manual equipment

Hand trucks, platform trucks, pallet trucks, carts and dollies are relatively inexpensive and flexible. They are appropriate for short distances, low-to-medium flow rates and operations where routes change frequently. Their limitations include dependence on operator effort, lower throughput and potential ergonomic risk.

Industrial trucks

Counterbalance forklifts carry loads on forks and are versatile for loading vehicles and handling palletised goods. Reach trucks are designed for narrower aisles and elevated storage. Order-picking trucks allow an operator to access individual cartons or cases. Side loaders are useful for long loads such as timber or steel. Powered pallet trucks suit horizontal movement over moderate distances.

Selection requires attention to rated capacity, load centre, lift height, turning radius, aisle width, battery or fuel requirements, floor conditions and operator visibility. A forklift rated at a stated capacity does not necessarily lift that capacity at every height or load-centre distance. The manufacturer’s capacity plate and applicable safety rules must govern operation.

Conveyors

Belt conveyors transport cartons, parcels and unit loads continuously. Roller conveyors are suitable for rigid-bottom loads; powered rollers assist movement where gravity is insufficient. Chain conveyors handle robust pallets and containers. Screw conveyors are used for some bulk materials. Sortation conveyors direct items to destinations using diverters, pop-up wheels or cross-belt mechanisms.

Conveyors provide predictable flow but may reduce flexibility and create a single point of failure. Guards, emergency stops, access controls and safe interfaces with people are essential.

Cranes and hoists

Overhead cranes, gantry cranes and hoists handle heavy or bulky loads while preserving floor space. Their selection depends on safe working load, span, lift height, duty cycle, hook travel, load shape and building structure. Suspended loads create significant risks and require exclusion zones, inspection and trained operators.

Automated systems

Automated storage and retrieval systems, automated guided vehicles, autonomous mobile robots, robotic palletisers and robotic picking systems can improve repeatability, density and traceability. They are most valuable where volumes are sufficiently stable, labour is constrained, safety improvement is important or accuracy requirements are high.

Automation does not eliminate management responsibility. It creates requirements for system integration, cybersecurity, maintenance, exception handling, battery management, safe human–machine interaction and business continuity. A technically advanced system can underperform if data quality, slotting logic or replenishment processes are poor.

4. Selecting handling equipment

A structured selection process is preferable to informal preference. The following sequence is practical:

1. Define the material, load, route, frequency and service requirement.
2. Identify constraints such as aisle width, floor loading, ceiling height, temperature and hygiene.
3. Establish safety, legal and environmental requirements.
4. Generate feasible manual, mechanised and automated alternatives.
5. Compare capacity, throughput, flexibility, reliability and integration requirements.
6. Evaluate total cost of ownership.
7. Test the preferred design through trials, simulation or pilot operation.
8. Implement training, inspection, maintenance and performance measurement.

Useful performance measures include handling rate, travel distance, equipment utilisation, availability, damage rate, energy consumption, labour hours per unit and safety incidents. Equipment utilisation should not be confused with maximum theoretical capacity. A machine operating continuously at its limit may have inadequate resilience for peaks, maintenance or variability.

A basic total-cost perspective is:

where TCO is total cost of ownership over the evaluation period; C₀ is acquisition and installation cost; Cₒ is operating cost; Cₘ is maintenance cost; Cₑ is energy cost; C_d is expected cost of damage, downtime and disruption; and Vᵣ is residual value. The expression is a decision framework rather than a complete financial model. For investment appraisal, the timing of cash flows, discount rates, taxes and financing should also be considered.

5. Packaging systems

Packaging is a system of materials and design features that contains, protects, handles, identifies and communicates information about a product. Packaging may be classified as:

• Primary packaging: directly contacts or encloses the product.
• Secondary packaging: groups primary packages, such as cartons or shrink bundles.
• Tertiary packaging: supports transport and storage, such as pallets, stretch wrap and shipping cases.
• Transit packaging: the wider system protecting products against vibration, shock, compression, puncture, moisture, temperature and handling hazards.

Packaging performs six linked functions:

1. containment;
2. protection;
3. convenience and handling;
4. information and identification;
5. security and tamper evidence;
6. marketing and presentation.

A package should be designed for the entire distribution environment. Laboratory tests may not represent actual vibration, repeated impacts, weather exposure, poor roads, stacking variability or manual handling. Distribution-system data and field damage records are therefore important.

Packaging materials

Paperboard and corrugated fibreboard are light, printable and widely recyclable. Their strength is affected by moisture, compression duration and flute orientation. They are effective for cartons but may require reinforcement for heavy or wet conditions.

Wood is used for pallets, crates and cases. It offers strength and repairability but varies in quality and may require treatment or documentation for international movement.

Plastics include films, strapping, crates, drums and returnable containers. They offer moisture resistance and durability, but material selection, contamination and end-of-life recovery must be considered.

Metal provides high strength, security and resistance to impact or temperature. It is heavier and may be more expensive, although it can be highly reusable and recyclable.

Glass provides chemical stability and product visibility but is fragile and heavy, requiring cushioning and careful handling.

The best material is not automatically the lightest or cheapest. It must provide adequate performance at the lowest reasonable life-cycle burden.

Protection design

Packaging protection may involve cushioning, blocking, bracing, restraint, moisture barriers, thermal insulation and shock indicators. A fragile item should not be allowed to move freely within a carton. Empty space can increase impact energy, while excessive fill may transmit shock directly to the product.

Compression strength is relevant when cartons are stacked. The practical strength of a carton depends on humidity, storage duration, pallet pattern, corner alignment and whether loads are concentrated or distributed. Stretch film stabilises loads but should not be treated as a substitute for correct stacking or a structurally adequate carton.

Ergonomics and user safety

Packaging affects lifting, carrying, opening, cutting, pouring and disposal. Excessively heavy cases, slippery surfaces, sharp edges and difficult closures create risk. Good practice includes manageable case weights, hand holes where appropriate, clear orientation markings, stable bases and opening systems that do not require excessive force.

Ergonomic design must consider the whole task: frequency, reach distance, posture, floor condition, lifting height and team coordination. A package that is acceptable as a single lift may be unsafe when handled hundreds of times per shift.

6. Pallets, containers and unit loads

A unit load is a collection of individual items arranged and secured so that they can be handled as one entity. Unitisation reduces touches, speeds loading and unloading, supports inventory control and can reduce damage. Common unit loads include pallet loads, roll cages, bins, totes, drums and intermodal containers.

A pallet is a portable platform used to support and handle goods. Pallets may be block or stringer designs and may be made from wood, plastic, metal or composite materials. Selection depends on load, rack compatibility, hygiene, reuse cycle, repairability, export requirements and handling equipment.

Pallet decisions should consider:

• deck dimensions and usable surface;
• safe working load and racking load;
• fork and pallet-jack entry;
• two-way or four-way entry;
• nesting or stackability when empty;
• moisture, hygiene and pest-control requirements;
• compatibility with vehicles and warehouse locations;
• ownership, pooling, return and repair arrangements.

Containers and totes may be collapsible, stackable, nestable, reusable or disposable. Reusable containers can reduce waste and product damage, but their benefits depend on return distance, loss rates, washing requirements, reverse logistics and utilisation. A reusable container travelling empty for long distances may have a greater environmental burden than a well-designed one-way package.

Load stability

A stable unit load has a low tendency to slide, tip, lean or collapse. Stability is affected by centre of gravity, friction, interlocking pattern, wrap tension, straps, corner boards, load height and acceleration during transport. Heavy items should generally be placed low, and the load should remain within the pallet footprint unless specifically designed otherwise.

Pallet patterns may be column-stacked or interlocked. Column stacking can provide better vertical compression strength, while interlocking may improve lateral stability. The appropriate pattern depends on carton strength, product fragility and transport conditions. Overhang should be avoided unless the pallet and load system has been engineered for it.

7. Cube utilisation and load planning

Cube utilisation concerns the use of available three-dimensional space. It is not identical to weight utilisation. A vehicle may be full by volume but below its legal mass limit, or full by mass while substantial volume remains unused.

For a rectangular package, volume is:

where V is volume, L is length, W is width and H is height, all expressed in consistent units.

A basic cube-utilisation ratio is:

where U_c is cube utilisation; V_u is the volume occupied by the load; and V_a is the usable internal volume of the vehicle, container, storage location or package. The ratio is meaningful only when both volumes refer to the same boundary and when access, clearances, irregular shapes and safety restrictions are treated consistently.

For a rectangular vehicle compartment, usable volume may be estimated as L_v × W_v × H_v, but doors, wheel arches, evaporator units, load restraints and required clearances reduce usable space. Therefore, a theoretical calculation is an upper bound, not a guarantee of actual loading.

Worked example: carton and pallet pattern

A carton measures 400 mm × 300 mm × 250 mm. A pallet has a usable deck of 1,200 mm × 1,000 mm. Ignoring overhang and clearance, a simple orientation permits:

• along pallet length: 1,200 ÷ 400 = 3 cartons;
• along pallet width: 1,000 ÷ 300 = 3 complete cartons.

Thus, 3 × 3 = 9 cartons fit per layer. If the permitted load height is 1,500 mm and each carton is 250 mm high, six layers fit. The unit load therefore contains 9 × 6 = 54 cartons.

The carton volume is:

The product volume is 54 × 0.03 = 1.62 m³. The occupied rectangular envelope of the pallet load is 1.2 × 1.0 × 1.5 = 1.80 m³. The product-to-envelope ratio is therefore:

This does not mean that 90% of a truck is utilised. It measures product volume relative to the selected pallet-load envelope. Film, pallet thickness, voids and stability clearances must be included when evaluating actual vehicle cube utilisation.

Weight utilisation

Weight utilisation may be expressed as:

where U_w is weight utilisation, M_l is actual load mass and M_c is the permitted capacity. The permitted capacity must reflect the most restrictive applicable limit, such as vehicle legal mass, pallet rating, rack rating, floor loading or equipment capacity. A high percentage is not necessarily desirable if it leaves no margin for variation or safe operation.

8. Packaging and unitisation decision framework

A professional decision should balance the following criteria:

Trade-offs are unavoidable. Reducing packaging may lower material consumption but increase damage. Increasing pallet height may improve cube utilisation but reduce stability or exceed rack and vehicle limits. Reusable packaging may reduce waste but introduce cleaning, tracking and return costs.

9. Compliance, governance and sustainability

Packaging and handling operations must comply with applicable national and international requirements. Examples include dangerous-goods packaging and labels, food-contact controls, pharmaceutical integrity requirements, customs and marking rules, wood-packaging treatment requirements, worker-safety legislation, waste obligations and transport weight restrictions. Requirements vary by jurisdiction and product; organisations must consult current official standards and competent authorities rather than relying on informal summaries.

Governance includes documented specifications, approved suppliers, inspection routines, change control, incident reporting and traceability. A packaging change can affect product quality, insurance, customs clearance and customer acceptance. It should therefore be validated before full implementation.

Sustainability should be assessed using a life-cycle perspective. Relevant measures include packaging mass per shipped unit, recycled content, recovery rate, return cycles, damage rate, empty return distance, energy consumption and emissions. Lightweighting is beneficial only when functional performance remains adequate. Reuse is beneficial only when the container achieves enough productive cycles and its cleaning and return impacts are acceptable.

10. Digital technologies and AI

Barcode and RFID systems identify products, containers and handling assets. Warehouse management systems assign storage locations, direct picking and record movements. Equipment-control systems coordinate conveyors, sorters and automated storage systems.

Data analytics can identify damage hotspots, underused cube, excessive touches, idle equipment and recurring ergonomic risks. AI may support demand-based slotting, vision inspection, predictive maintenance and route optimisation. However, AI recommendations depend on accurate data and clearly defined objectives. A model optimising throughput alone may increase damage or worker strain. Human oversight, explainable decision rules, cybersecurity and data governance remain essential.

11. Illustrative case: regional food distributor

Background

A regional food distributor supplies supermarkets from a 12,000 m² distribution centre. Products arrive in corrugated cartons of different sizes and are shipped on standard pallets. The operation reports high carton damage, long vehicle-loading times and frequent manual lifting injuries.

Problem

An initial review finds three causes: mixed carton sizes create unstable pallet patterns; heavy cartons are placed above lighter cartons; and operators rebuild loads at dispatch because inbound pallets do not match outbound customer requirements. Vehicle cube utilisation is also poor because pallet heights vary substantially.

Analysis

The distributor maps product flows and records carton dimensions, mass, damage location, pallet height and handling touches. It discovers that damage is concentrated in tall, lightly wrapped loads and in cartons exposed at pallet edges. The existing pallet pattern prioritises the number of cartons per layer but ignores compression strength and centre of gravity. The company also measures both volume and mass utilisation because some delivery routes are weight-constrained while others are cube-constrained.

Approach and solution

The distributor introduces a packaging and unit-load standard with four carton families, defined maximum gross case masses and clearer orientation markings. Heavy cases are assigned to lower layers. A pallet-pattern database identifies stable layer arrangements, and corner boards are added for selected products. Stretch-wrap settings are standardised and checked by supervisors.

At receiving, compatible pallets are identified for direct cross-docking. Other goods are stored in a dedicated pallet zone. At dispatch, a load-planning tool groups orders by route, vehicle capacity, delivery sequence and stability rules. Operators receive ergonomic training and use powered pallet trucks for longer travel distances. Damage, loading time, cube utilisation, injury indicators and packaging consumption are monitored monthly.

Outcome

After a three-month pilot, the distributor records fewer damaged cartons, shorter loading times and improved consistency of pallet heights. The improvement does not result from one piece of equipment; it results from coordinating carton design, pallet patterns, wrapping, information and work methods. The company continues to monitor whether increased packaging materials are justified by reduced product loss and whether returnable components are recovered.

Learning points

1. Unitisation is a system decision, not merely a pallet decision.
2. Cube utilisation must be considered together with mass, stability and access.
3. Packaging changes should be validated using actual distribution conditions.
4. Ergonomics and product protection can reinforce each other when loads are standardised.
5. Performance measurement should include damage, labour, safety, cost and environmental indicators.

12. Challenges and limitations

Materials-handling design faces uncertainty in demand, product mix, labour availability, supplier packaging, equipment breakdowns and customer requirements. Standardisation can improve efficiency but may reduce flexibility for unusual products. Automation can increase throughput but may create capital exposure and dependence on specialist support. High-density storage may reduce travel but make access slower or more complex. Reusable systems can fail when assets are lost or reverse logistics are poorly controlled.

Quantitative measures also have limitations. Cube utilisation does not capture accessibility or damage risk. Equipment utilisation may conceal congestion. Cost comparisons can be misleading if they omit downtime, training, safety and end-of-life costs. For this reason, decisions should combine quantitative analysis, operational trials, worker consultation and risk assessment.

Best-practice checklist

• Begin with product and process requirements, not equipment preference.
• Minimise touches and unnecessary travel.
• Standardise pallets, cartons and containers where practical.
• Keep heavy loads low and within the support footprint.
• Validate packaging under realistic distribution hazards.
• Include ergonomics, safety and accessibility in specifications.
• Distinguish theoretical from usable volume.
• Evaluate total cost of ownership and life-cycle impacts.
• Use accurate identification and traceability data.
• Plan maintenance, training, inspection and emergency response.
• Pilot major changes before full-scale deployment.
• Review performance continuously using damage, productivity, safety and sustainability measures.

Chapter Summary

Materials handling, packaging and unitisation are interdependent elements of logistics system design. Materials-handling equipment should be selected according to product characteristics, flow, facility constraints, safety, flexibility, capacity and total cost of ownership. Manual equipment, industrial trucks, conveyors, cranes and automated technologies each have appropriate operating contexts and limitations.

Packaging contains, protects, identifies and facilitates products. Effective packaging balances protection, handling efficiency, ergonomics, compliance, cost and environmental performance. Pallets, containers and other unit loads reduce handling and improve control when they are stable, compatible with equipment and suited to the distribution environment.

Cube utilisation measures the use of three-dimensional capacity, while weight utilisation measures use of mass capacity. Neither measure alone is sufficient; access, stability, legal limits, product protection and operational variability must also be considered. Digital systems can improve traceability, planning and predictive control, but data quality and governance remain essential. The most effective solutions are integrated, tested in realistic conditions and measured across productivity, damage, safety, cost and sustainability.

Key Terms

Materials handling: Movement, storage, protection and control of materials within a logistics system.

Unit load: Multiple items consolidated and secured so they can be handled as one entity.

Pallet: Portable platform supporting goods for handling and storage.

Tertiary packaging: Packaging used for transport and storage, such as pallets and stretch wrap.

Primary packaging: Packaging that directly contacts or encloses the product.

Secondary packaging: Packaging that groups primary packages.

Cube utilisation: The proportion of usable three-dimensional capacity occupied by a load.

Weight utilisation: The proportion of permitted mass capacity used by a load.

Load centre: Horizontal distance from the fork face or support point to the load’s centre of gravity.

Rated capacity: Maximum permitted load under specified operating conditions.

Cross-docking: Transfer of received goods to outbound dispatch with limited or no storage.

Stretch wrap: Stretchable film used to stabilise a unit load.

Blocking and bracing: Methods of preventing load movement through physical support and restraint.

Ergonomics: Design of work, equipment and packages to fit human capabilities and limitations.

Total cost of ownership: Acquisition, operating, maintenance, risk and residual-value costs over an asset’s life.

Returnable packaging: Packaging designed for repeated use and return through a logistics cycle.

Intermodal container: Standardised container transferable among transport modes.

Slotting: Assigning products to storage or picking locations.

Traceability: Ability to track a product, package or load through specified stages of the supply chain.

Review Questions

Short Answer Questions

1. What is a unit load, and why does unitisation improve logistics performance?
2. Identify four characteristics of a product that influence handling-equipment selection.
3. Distinguish primary, secondary and tertiary packaging.
4. Why is cube utilisation different from weight utilisation?
5. State three factors that influence pallet-load stability.

Long Answer Questions

1. Explain the principles that should guide the design of a materials-handling system.
2. Compare manual equipment, industrial trucks, conveyors and automated systems, including their advantages and limitations.
3. Discuss how packaging can simultaneously support product protection, ergonomics and sustainability.
4. Explain the process of selecting a pallet or reusable container for a distribution operation.
5. Discuss why total cost of ownership is more useful than purchase price when evaluating handling equipment.

Analytical / Application Questions

1. A carton measures 500 mm × 400 mm × 300 mm. A pallet has a usable deck of 1,200 mm × 1,000 mm and permits four layers. Determine a feasible number of cartons per layer and per pallet, stating your orientation assumptions.
2. A distribution centre is considering taller pallet loads to improve vehicle cube utilisation. Analyse the operational, safety, equipment and packaging factors that should be assessed before approval.
3. Design a packaging and unitisation approach for a fragile, moisture-sensitive product shipped internationally. Justify your choices in relation to protection, compliance, handling, sustainability and reverse logistics.

Multiple Choice Questions with Answers

Question 1

Which principle requires materials handling to be designed as part of the complete logistics process?

A. Systems principle

B. Gravity principle

C. Maintenance principle

D. Marketing principle

Correct Answer: A. Systems principle

Question 2

Which equipment is generally most suitable for a stable, high-volume flow between fixed points?

A. Hand truck

B. Continuous conveyor

C. Manual cart

D. Platform ladder

Correct Answer: B. Continuous conveyor

Question 3

What is the primary purpose of tertiary packaging?

A. Direct contact with the product

B. Product advertising only

C. Transport and storage support

D. Replacing inventory records

Correct Answer: C. Transport and storage support

Question 4

A unit load is best defined as:

A. A single item at maximum legal weight

B. A group of items handled as one entity

C. Any product stored on a shelf

D. An empty transport container

Correct Answer: B. A group of items handled as one entity

Question 5

For a rectangular package, volume is calculated as:

A. Length + width + height

B. Length × width × height

C. Mass ÷ density only

D. Length × height ÷ width

Correct Answer: B. Length × width × height

Question 6

A load occupies 8 m³ in a usable vehicle volume of 10 m³. What is cube utilisation?

A. 8%

B. 18%

C. 80%

D. 125%

Correct Answer: C. 80%

Question 7

Which arrangement generally places heavy cartons most appropriately?

A. On the highest layer

B. At the outer edge only

C. On lower layers within the pallet footprint

D. Loose above the load

Correct Answer: C. On lower layers within the pallet footprint

Question 8

Which factor is especially important when selecting a forklift for elevated storage?

A. Colour of the cartons

B. Lift height and rated capacity at the relevant load centre

C. Product advertising design

D. Number of customer invoices

Correct Answer: B. Lift height and rated capacity at the relevant load centre

Question 9

What is a major limitation of cube-utilisation measurement?

A. It cannot use dimensions

B. It ignores all volume

C. It may not reflect access, stability or damage risk

D. It applies only to liquids

Correct Answer: C. It may not reflect access, stability or damage risk

Question 10

Which statement about reusable packaging is most accurate?

A. It is always more sustainable than one-way packaging

B. It eliminates reverse logistics

C. Its benefit depends on reuse cycles, returns, cleaning and losses

D. It cannot be used for food products

Correct Answer: C. Its benefit depends on reuse cycles, returns, cleaning and losses