Shrink wrapping machines wrap a loose plastic film around a product or group of products, and then heat the film to form a tight wrap.
See PPMA Member companies who supply a comprehensive range of wrapping machines, including Shrink Wrapping machines.
How do you shrink wrap?
The principle of shrink wrapping is simple; it works by loosely wrapping a product in film, applied either manually, semi-automatically or in a fully automated process. The film is then shrunk by a handheld heat gun, passing on rollers through a heat tunnel or in a heat chamber. When you heat shrink wrap, it contracts around the surface of the goods to form a protective film barrier.
Why should you use shrink wrap?
The versatility and multiple benefits of shrink wrap means that it is used for an extensive number of products and materials.
Shrink wrap performs the key function of protecting goods against dust, moisture and dirt. That is important for all products, but essential for food and pharmaceuticals. Because of the effectiveness of the seal, fully shrink-wrapped goods also stay in optimum condition for longer than if exposed to the atmosphere.
Typically, shrink wrap is stronger than overwrapping or stretch wrapping. The film is usually based on polyolefin, PVC, polyethylene or polypropylene. It comes in a variety of strengths, thicknesses and clarity, so it can be used for different products according to weight and the level of protection required, including the need for protection from light.
Shrink wrap also holds its shape very well, so products always look their best, which is a critical consideration for consumer products. It clearly shows if there has been any interference or tampering, an issue of prime importance for cheese, meats, prepared meals and pharmaceuticals, as well as bundles of currency or sensitive documents.
Compared to cardboard and plastic, shrink wrap is very space-efficient, taking up no more room in storage, transport or on the shelf than the products themselves. It is also lighter, so it is easier and less costly to handle and transport. It is suitable for products or groups of products of all kinds, shapes and sizes. It is often used for groups of bottles or cans, or to combine products in a multipack.
Shink wrap is often used for transit wrapping and protective packaging for larger items, such as doors or even bricks on a pallet. It is also used to wrap and protect scaffolding, roofs, cars, vans, boats and loaded pallets.
A further key advantage is that shrink wrap machinery and materials are relatively low-cost. Smaller producers and operations can use simple shrink wrap machines with limited outlay, using either manual or semi-automatic processes. Higher investment allows for fully automatic systems, with savings on labour and the avoidance of tedious and repetitive manual work.
Types of Shrink Wrapping Machinery
- Using hot air, hot water, steam or radiant heat, the heat shrink wrapping process takes place as the product passes through a heated tunnel.
- The product is placed within a heated chamber for shrink wrapping.
- This method is used when the type of thermoplastic being used requires more time to heat than others.
- Shrink oven wrapping machienry also provides a more constant heat. Shrink ovens are usually used in low-speed and low-cost operations.
- A shrink frame wraps film around a product by moving over the product's surface.
- This method works best on regular-shaped large items, and in cases where a group of products need to be packaged together.
- A dip tank, as the name suggests, is a type of shrink wrapping machinery which shrinks thermoplastic film around a product by dipping it in hot water.
- The dip tank method is used in the packaging of cheese, as it has the added benefit of limiting product temperature rise.
- Flow wrap sleevers are often used to apply external labels to packages, particularly that of beverages.
- The label is placed over the product and then shrunk tight.
- Find more information on flow wrap sleevers here.
- Large objects can be wrapped by mounting a stack on a stretch wrapping machine turntable or rollers integrated into a production line.
- A perimeter sealing machine is not exactly shrink wrap machinery, but it does use heat to seal packaging in a similar way.
- Heat is applied to the open end of a filled package to seal it.
- Find out more about perimeter sealing machines here.
- Single-reel sleeve wrapping machines operate in a different way to standard shrink wrapping machinery. For example, there is no form of sealing jaw involved with this equipment.
- A single reel of film is stretched and cut to length, before being applied around the product, overlapping underneath the package. The overlap is sealed within a heat tunnel.
- This method is ideal for wrapping multipacks of cans, jars and bottles.
- Find out more about single-reel sleeve wrapping machines here.
- Twin-reel sleeve wrapping machines use two rolls of film simultaneously to provide robust hold of packaged products.
- The ideal choice for large products (e.g. pallets, doors, multipacks of large items), this method can complete each product quicker and with more strength of hold than a single reel sleeve wrapper.
- The twin-reel sleeve wrapper operates at around 40 cycles per minute, making it more suitable for low- or mid-speed output on products that have undemanding packaging requirements.
- Find out more about twin-reel sleeve wrapping machines here.
Find Shrink Wrapping Machine Suppliers with PPMA Group
See a full list of PPMA Member companies who supply a comprehensive range of shrink wrapping machinery.
- Flat rollstock
- Centrefold film
- Thermoplastic film
- Heat wrapping
- Preformed shrink bags
- Single-reel sleeve wrapping
- Twin-reel sleeve wrapping
- Perimeter sealing
- Flow-wrap sleeve
- Shrink ratio
- Heat-shrink tubing
- Heat gun
- Dip tank
- Shrink oven
- Shrink tunnel
- Shrink frame