Packaging materials and containers
The packaging industry makes use of a wide variety of materials and containers for a multitude of consumer and industrial products. Choices are driven by the requirements of different products including protection, hygiene, ease of handling, tamper-proofing, branding and regulatory compliance.
The choice of packaging machinery depends on its ability to use the materials and containers required for specific products. You can explore the full range of packaging machinery available from Automate UK members here.
Types of Packaging
What are the types of packaging?
Many flexible and rigid materials are used for different types of packaging, and the vast majority are based on paper, plastic, glass and metal used for packing and packaging containers designed for specific types of consumer and industrial products.
Paper for packaging
Single layers of paper are well known in their use as paper bags, envelopes and as paper wrapping. The use of uncoated papers is limited by its absorbency, so it is only used for dry products. Coatings on papers, for example wax or a plastic film coating, can provide moisture resistance and so are suitable for various food products and components which need to stay dry. Papers which are vulnerable to tearing are used in decorative packaging, while robust, tear-resistant coated papers can be used for wrapping heavy, angular objects including building materials.
Cardboard, technically, is a single sheet of thick gauge paper and has multiple uses in packaging such as in heavy envelopes, tubes and cartons. Cardboard is often confused with cartonboard which consists of layers of paper formed into a strong, flexible material for cartons and other containers.
The strongest type of paper-based packaging material is corrugated cartonboard. One or more layers of paper in a wave form are sandwiched between layers of board. The result is a strong and very rigid material which is principally used to make strong protective boxes for larger and heavier products.
Paper is also the main component of drinks cartons, which are usually made from 75% paper, 20% polyethylene and 5% aluminium foil.
Flexible Plastic packaging
Plastic is used throughout the world of packaging. Flexible plastic film is easy to apply, either by hand or machine, and is used to wrap products of all shapes and sizes, from small individual items through to objects as large as cars, boats and industrial machinery.
Plastic stretch film comes in many varieties tailored to different uses and for running different types of packaging machinery. The key characteristic of stretch film is that has a greater or lesser degree of elasticity. It is applied by stretching over a product, cutting to size, and sealing either through its clinginess, or with a heat seal or adhesive. Stretch film is most usually made from polyethylene (PE). It is generally used to form a protective barrier, but is not as strong as other types of plastic film.
Plastic shrink film is mainly made from low density polyethylene (LDPE), polyvinyl chloride (PVC) and polyolefin (POF). Shrink film is loosely placed over products, then heat is applied to shrink the film to form a tight fit. Heat can be applied by a hand gun, or in a heat tunnel. Shrink film can be pre-printed with branding and consumer information, and can also be printed with variable information such as batch numbers, use by dates and weight.
Thin, lightweight LDPE is used to wrap newspapers, bread and other products and in the production of bubble wrap. Bubble wrap features regularly spaced, air-filled bubbles within the film layers which cushion fragile products from shocks. Bubble wrap is not used for external packaging but is regularly used on products within cartons and other outer packaging.
Flexible stand up pouches are frequently made from linear low density polyethylene (LLDPE). The material is stronger than most LDPE, even in thin gauges, and is widely used for liquid and viscous foods. LDPE pouches have the advantage of allowing for resealable closures.
Expanded polystyrene (EPS) is used for in box protective packaging in the form of loose chips which are used to pack around fragile products. Known as void fill, this use of polystyrene has the advantage of being light and also provides thermal insulation.
Plastic is also used for bags ranging from lightweight packaging through to heavy, bulky gardening or building products. Plastic bags are generally made from polyethylene or stronger polyvinyl chloride (PVC).
Plastic is also used in bag-in-box packaging for wine and other liquids, wherein a filled bag is protected by a carton with a valve to release the contents.
Rigid plastic packaging
Heavier grades of plastic are used for rigid containers and other forms of packaging. High density polyethylene (HDPE) is used to make plastic bottles for milk and other liquid products including bleach and detergents.
Polyethylene terephthalate (PETE) is a tough, light, see-through plastic used for drinks bottles, especially for soft drinks and water where seeing the product is an important part of the consumer experience.
Clamshell packaging and blister packs are usually made from rigid PVC, as opposed to the flexible PVC used for plastic bags.
Polypropylene (PP) is an inflexible plastic that can stand up to high temperatures used in production and filling. This allows it to be used for bottles and containers for pharmaceuticals, cooked foods and automotive products.
Metal packaging
The majority of canned drinks are in lightweight aluminium, while around 25% globally are canned in tin-plated steel. Tin-plated steel is the most popular material for tinned foods and provides a very strong, almost fully damage-proof container with a long shelf life (tin has exceptional corrosion resistance).
Metal packaging also takes the form of aluminium foil. Thin gauge foil is flexible, strong and lightweight. It withstands very low or high temperatures, and can be used for both freezing and cooking. It is a barrier to UV light which can degrade certain products, and it is also impervious to liquids and gases. It does not react with most foods, and is available with protective coatings for use with any food which is affected by the metal. The foil can also be printed so can feature branding and other consumer-facing information.
In large format industrial packaging, heavy gauge stainless steel is used for beer kegs, and ribbed steel for oil drums.
Glass Packaging
Glass bottles and jars are well-known as packaging for food and drink, from baby foods to fine wine. Glass is inert and provides a total barrier to liquid and gas. Glass can be moulded into an almost infinite number of shapes and sizes, and can be fully transparent to allow products to be clearly visible, or be coloured for a distinctive appearance. Glass containers can withstand significant amounts of pressure, although it will crack and potentially shatter in extreme conditions. Bottle closures are generally crown caps, screw caps or corks, while jars are sealed with various types of crimped or screwed lids.
Find Packaging Materials & Containers Suppliers
See a full list of Automate UK Member companies that supply a comprehensive range of packaging materials and containers suppliers.