Going further

The key functions of packaging are:

  • Containment or aggregation
  • Physical protection
  • Barrier
  • Information
  • Legal / Regulatory Requirements
  • Marketing
  • Convenience and Security
  • Environment / sustainability

 

Content and aggregation

The key to establishing the containment or aggregation function of a pack is to understand the physical nature of the product and what happens during its life cycle.
The first stage of the product life cycle is filling or packaging. If the product is a discrete solid item it will need to be picked up and placed in the pack or at least guided into it. This may be done mechanically or manually.

If the product is a powder or granules it is likely that the pack will require a wide opening to allow the product to flow into it.

Viscous liquids, creams or pastes are also difficult to fill through a narrow opening. These products can be hot-filled to reduce viscosity, as long as the container or package will withstand the temperature without detriment or failure.

Free-flowing liquids can be filled via narrow openings. All liquids require a non-porous container, so uncoated paper for example would obviously be unsuitable.
With gas products, the package must have a gas tight seal to prevent escape. Gases may be filled under pressure into a sealed container via a valve or alternatively liquefied. These methods mean the package has to withstand pressure, and also extreme cold for liquefied gases. During storage and transit the packages must be able to maintain their integrity, not fail under the weight or pressure of the product, and not leak liquid or gas products. 

When products have sharp edges the package must retain the product without tearing or bursting and protect workers and customers from injury.

For aseptic products the package must withstand sterilisation temperatures and pressures as well as maintaining a hermetic seal.

Physical protection

Again physical protect is important throughout the life cycle; although it is probably most important in storage and transport.

There are many ways in which products can be physically damaged these include:

Mechanical shock – This usually comes from impact or dropping. To design effective packaging we must consider possible drop heights, impacts from the side and above, and the markets that the products will be shipped to.

Mechanised movement of palletised loads may still leave a degree of manual handling and the risk of significant impacts. Supply chains in developing countries can easily include donkey carts or pack animals, and the condition of roads can put products at risk of damage even when trucks are used.

The focus is often on protecting fragile products, but mechanical shock can be a significant hazard for non-fragile products if the package ruptures or bursts.

Vibration – Vibration is most likely to occur during transport and may be high or low frequency, and high or low amplitude. Possible sources include high frequency road/vehicle suspension vibration, large bumps in the road, ship and aircraft engines, and warehouse machinery.

When a product is subject to vibration at its natural resonant frequency it will also start to vibrate, and these vibrations will get stronger.  The most obvious concern is a physical break in some delicate part such as electronic connections, but vibration can also cause abrasion or cause mixtures to separate.

Packaging can be designed to isolate the product or attenuate the vibration.

Abrasion – Products with fine or delicate surface finishes are susceptible to abrasion. One option may be to ensure the product is firmly secured and cannot rub against anything. This may be combined with a soft non-abrasive pack liner.

Deformation – Many products are boxed and stacked on pallets. The package needs to be able to withstand the combined weight of any boxes above it on the pallet. If pallets are stacked upon pallets the lowest boxes on the lowest pallets need to withstand the combined weight of the boxes and pallets above.

Temperature – Frozen goods are one type of product that is obviously affected by temperature, but elevated temperature can prematurely age many products that we think of as stable at ambient temperatures including foodstuffs, toiletries and cosmetics. Products can be exposed to wide variations in temperature in the topics and arctic regions but even in temperate zones the temperatures inside trucks in the height of summer or overnight in winter can be extreme. Most products will withstand short periods of temperature fluctuation but where products are particularly sensitive packaging can help to protect them, often in combination with temperature-controlled distribution.

Relative humidity – As well as varying across geographic zones humidity can also change significantly where micro-climates are formed e.g. in shipping containers and in ships’ holds.

High humidity can accelerate corrosion of some products and cause deterioration in hygroscopic products. Paper products and packaging can be degraded by high humidity and sudden changes in humidity can cause paper-based items to bow and warp.

Water – Water can cause deterioration in products and packaging throughout the supply chain and at the point of use.

Oxygen –See barrier section

Barrier

Where products are sensitive to light, oxygen, carbon dioxide, or biological hazards, or are volatile or corrosive chemicals themselves, a barrier is needed throughout the product life cycle. Barriers may be used to prevent ingress or egress.

Oxygen (together with water or water vapour) is a principle factor in spoilage of many products from food and beverages to pharmaceuticals. Products sensitive to oxygen must be protected from it right up to the point of use. Typically this involves packaging with minimal oxygen present (small head space in pack), replacing air in pack with modified atmosphere low in oxygen, or incorporating oxygen scavengers in the pack and using a barrier to prevent further oxygen ingress.

Conversely, packaging red meat (beef) under a modified atmosphere with higher concentrations of oxygen helps to maintain its ‘fresh’ colour and the barrier film helps to keep the oxygen within the pack.

With carbonated drinks the barrier keeps carbon dioxide within the product.

Light can also initiate oxidation and degradation of foods, beverages, pharmaceuticals and coloured items that fade in sunlight. This can be an issue at various stages of the life cycle. Clearly the intensity of sunlight is far greater in equatorial zones, but we must also consider how products are displayed and how long they can be kept in a shop window.

Some volatile or corrosive products are stable and easily contained until contaminated. For example sodium hydroxide pellets are relatively easy to handle whilst dry, but adding water makes a highly corrosive solution and generates a lot of heat.

Information

As a basic level the packaging must identify the product. In addition there is a wide range of legally required information which must be carried on the pack before we consider information useful to people in the supply chain and the ultimate consumer.

Starting from the point of packaging the pack must inform those in the supply chain. This information may well include basic identification, batch numbers, expiry dates, item codes, bar codes, quantity, storage instructions, fragility, stacking heights and importantly any hazard presented by the product. At the point of sale there may be further information on storage and display and of the will be user instruction for the consumer once purchased. For medicinal and similar products there may be instructions for the professionals dispensing them which differ from consumer instructions.

Legal / regulatory requirements

The most common legal requirements for packaging relate to the following areas:

  • Weights and measures
  • Best before / use by dates
  • Country of origin (exporting outside of the EC)
  • Contents (e.g. mixed product packs – desktop kits etc.)
  • Ingredients
  • CE marking - mandatory conformity marking for products placed on the market in the European Economic Area
  • Electrical standards
  • Warnings
  • Health & Safety warnings for movement of heavy goods
  • Chemical/Hazardous products

In addition to these there are:

  • Patents, trade marks and copyright
  • Tamper evidence
  • Child resistance
  • Food contact

It is easy to focus on labelling as the key regulatory issue, but with tamper evidence, child resistance, food contact and chemical / hazardous products, pack performance is also central to legal compliance. For many of these areas there are tests and UN or ISO standards which the packaging must meet in order to sell the product.

Weights and measures issues also have a pack performance element. In the UK if a pack states a quantity or weight the actual contents must not be less that than value. The ‘e’ mark alongside a pack size means that for that batch the actual contents shall not be less, on average, than the nominal quantity. There is also a tolerance for the range around the average.

Table of tolerable negative errors    
Nominal quantity in g or ml Tolerable negative error
5–50 9%
50–100 4.5 units
100–200 4.5%
200–300 9 units
300–500 3%
500–1000 15 units
1000–10000 1.5%

 

Food contact legislation covers the materials which can be in direct contact with food and is intended to prevent contamination.

While most of these issues have relevance throughout the supply chain, factors such as child resistance become important once the product is with the consumer. Child resistance measures can prevent older people and adults with physical impairments from accessing their medicines. New standards have emerged providing for child resistance with adult accessibility.

See sidebox for some relevant UK regulations and information on how to comply.

Marketing

Before we can design packaging which will sell, we need to understand the consumer, the competition and the retail landscape.

Some purchasers are not the end consumer, and they may have different motivators when selecting products. General factors we want to know about the consumer / purchaser are:

  • Demographics
  • Psychographics
  • Purchase reason
  • Staple / essential item
  • Impulse item
  • Luxury / treat item
  • Gift item
  • Seasonal purchase
  • Preferred pack size / type
  • How / where the products is used

Factors to consider about the competition include:

  • Pack sizes / strengths
  • Target markets
  • Market share
  • Pricing structures
  • Marketing strategy
  • Strengths / weaknesses

Factors to consider about the retails landscape and method of sale include:

  • Physical store / on-line / mail order
  • Boutique niche store versus supermarket
  • Self service versus sales assistants / professionals (e.g. pharmacists)

Armed with this information we can begin to target consumers in terms of their preferences and physical and psychological needs, then either conform to a ‘must have’ pack type or establish a point of differentiation via pack type and ensure it is suitable for the retail environment.

Convenience / performance

For products to be packaged in significant volumes, automatic or semi-automated filling will be required. Many FMCGs are packed at rates between 60 and 600 per minute, making it difficult if not impossible for humans to place containers individually into the packaging line. A method of bulk loading, unscrambling and orienting the containers is required. They then have to be moved past filling and labelling units before being collated and packed into transit containers. For all this to be possible the containers must be stable and stand up on their own, or be held in some sort of cradle. Containers with irregular sides may topple on the conveyors.

At the end of a packaging line, products in transit containers (such as corrugated cases or shrink wrapped trays) are often stacked on pallets. These pallets may be moved by fork-lift  and stacked in warehouses and trucks. Even with a high degree of mechanisation, manual handling can occur throughout the supply chain and particularly in the retail environment. The implications of this are mostly associated with weight, shape, size and drop risk. The transit pack should be designed for easy handling and with large awkward shapes thought should be given to hand holds etc.

Once in store, the use of shelf-ready packs greatly improves shelf-stacking efficiency. These transit packs typically have a tear-off portion which reveals the products. For retail staff, picking a transit pack direct from a pallet and placing it on the shelf without unpacking is a major convenience. Stock outages and empty shelves are a major cause of lost sales so it is in the manufacturers’ and retailers’ interests to maintain full shelves.

For the consumer, convenience can be a key differentiator. Some common measures are:

  • Flip top caps allowing single handed use
  • Dispensers allowing single handed or hands free use
  • Measuring aids / devices to remove the need for further equipment
  • Built in applicators
  • Easy reclosing features for multi-use packs

Reduction, re-use and recycling can also provide convenience for the consumer. Minimised packaging using single or clearly-labelled materials helps with recycling and refill packs reduce the impact of disposing of more durable original containers.

Security

The security role of packaging focuses on preventing counterfeiting, loss, tampering or deliberate sabotaging.

Loss primarily occurs as a result of theft throughout the supply chain or sampling and grazing in the retail environment.

Many food products sold in jars are hot-filled and draw a vacuum on cooling, pulling the lid down. Jar lids often incorporate a flexible ‘button’ which will be raised if the pack has been opened. Jars can also be protected with a seal, which can simply be a label laid across the joint of the cap or closure. If the adhesive is strong and the material of the seal is fairly weak, it cannot be peeled and replaced without being destroyed.

Bottle caps often include a tamper-evident ring. Unscrewing breaks and detaches the ring from the cap.

Cans, blister packs, welded clamshells and ‘skin packs’ are intrinsically tamper-evident.

Items at risk of counterfeiting can be protected with overt and covert techniques. Overt techniques rely on the consumer being able to spot the difference between genuine and counterfeit packs, but anything that educates the consumer about the appearance of the genuine article also tells the counterfeiters what to copy. Common techniques include holograms, security pattern print (as on bank notes), water marks, unique patterned break patterns on seals and colour change inks. It can be extremely difficult to make a pack impossible to copy, so the aim is often just to make it difficult and expensive.

Covert techniques such as invisible inks, identifiers and printed micro-text are primarily directed at identifying counterfeits before they reach the consumer.  Other techniques include using track and trace of specific batches to investigate goods that turn up in the wrong distribution channel.

Counterfeiting appears to be most common in emerging markets. Tell-tale signs include:

  • Pre-printed batch details
  • Poorer (or better!) print/pack quality
  • Spelling mistakes in the text
  • Suspiciously low retail price

 

Environmental / sustainability

It is important to consider waste product as well as waste packaging. A cut piece of beef discolours in a matter of hours if left exposed to air. Since consumers are unlikely to buy brown beef it is packed in a sealed tray with a modified atmosphere to maintain a pink colour. Given the resources used to produce it, wastage of beef is arguably much worse than the possible waste of the packaging that contains it.

Many foodstuffs have short shelf lives without packaging and could not be produced, transported, sold and used in sufficient quantities without it. But we should not be complacent about the use of resources and the strength of public opinion regarding over-packaging.

Simplifying the pack

Technology packaging, for example, can have multiple fitments, multiple materials and accommodation for extensive instructions, but some newer smart phones packs are very simple, in 100% paperboard and without large instruction booklets. Other packs designed to re-enforce the eco credentials of products have an almost old-fashioned simplicity to them.

Reducing the weight of materials

This is significant for waste reduction and as a response to the increase in material costs. It has been seen in glass, plastic, metal and to a degree in paperboard packaging. The key challenge is to reduce the weight of material used whilst maintaining the structural integrity of the pack. When moulding containers this requires very good control of the material to avoid thin spots in the walls.

Refill packs

Refill pouches made from flexible laminates can be used across a wide range of food and household goods. The disadvantage is that shelf space must be found for both pack types.

Re-useable packs

Traditional re-useable packs (glass milk bottles and returnable drinks bottles) have all but disappeared from the UK as shopping has shifted to supermarkets and return/re-use infrastructures have been lost. Attempts by supermarkets to refill detergent bottles have not been successful. A tiny number of niche stores allow consumers bring their own containers.

Recyclable packs

Recycling has wide public awareness and acceptance. Some packages retain technical labelling (such as PP or HDPE with a recycling triangle symbol) but we are now seeing plain English instructions on many more consumer goods. Recycling of household waste is common across the UK although it is complicated by the differences between local authorities.

Packs with single or compatible materials are the easiest to recycle, but multiple materials, laminates or co-extrusions are often needed to preserve products and prevent further waste.