Shrink-Film.co.uk is a specialist website from Polybags.co.uk - the UK's number one polythene packaging manufacturer - dedicated to shrink film, shrink bags and shrink wrap.
Polybags produces and stocks a fantastic range of shrink wrap products, including shrink wrap, shrink pallet covers, shrink kits, heat sealers and shrink guns. To support this, we bring you a wealth of information on shrink wrap products - see our homepage or the 'Shrink wrap systems' section below for more information.
But shrink wrap is just part of the offering from Polybags, who produce a massive range of polythene products, including polythene rolls and bags available off-the-shelf in their millions, whilst you can custom-design much of our range and print it with your very own logo. Here are just a few of the main product categories that Polybags has to offer:
- Bubble packaging
- Bubble wrap is a protective polythene film filled with adjacent pockets of air which absorb the forces of impact when bumped or knocked and protect the contents inside. Suitable for fragile or delicate items, bubble wrap and bubble bags - simply bags made from bubble wrap - are a must-have packaging material for anyone who delivers products in the post or by courier.
- Carrier bags
- Carrier bags are the most popular polythene bag for retailers and consumers around the world. Polybags stocks a massive range of clear and coloured carriers to cater for any retail product, small or jumbo-sized, whilst they also produce personalised bespoke carrier bags, allowing businesses to design their own bag, complete with your company logo or branding.
- Clear polythene bags
- The perfect way to display the contents of your bag, clear polythene bags are available in a huge range of sizes from 2" to 48" wide and choice of thicknesses - from 100 to 800 gauge. Plus, if you can't find the right size for you, Polybags will produce the perfect size bag to meet your specifications.
- Display bags
- Made of high-clarity polypropylene film - a stronger, clearer and cheaper alternative to cellophane - retail display bags provide a perfect way for retailers to show off their products. Use these crystal clear bags to really make your products sparkle.
- Biodegradable, compostable and other eco-friendly packaging provides a great alternative to traditional polythene packaging that get the job done whilst looking out for the environment. Polybags can provide eco-packaging products to suit every need, from kitchen food waste bags and dog poo bags to biodegradable mailing bags and carrier bags.
- Garment covers & laundry bags
- Protect clothes in storage or transit with Polybags' fantastic selection of garment covers - thin polythene sleeves designed to fit over coat hangers to guard clothes from dust, dirt or moisture. Available in plain or pre-printed polythene, along with an excellent range of laundry bags, meaning Polybags have all your garment and laundry needs covered.
- Grip and zip seal bags
- Self-seal bags provide a simple way to protect bag contents from moisture or other contaminants. Grip seal bags contain a squeeze-shut seal, whilst zip seal bags and slidergrip bags feature a zip fastener. Both bags ensure no need for bag ties, clips or external seals, making them simple to use.
- Mailing bags
- Lightweight, strong and waterproof polythene bags with integral sealing strips that provide an excellent alternative to traditional envelopes and parcel packaging. Polybags stock a huge range of clear and coloured mailing and courier bags, including economy, heavy duty, high security, tamper-proof, bubble-lined and high-impact metallic mailers.
- Poly tubing and sheeting
- Polythene rolls are available with a wide range of plastic sheeting and tubing to cater for a variety of tasks. Plastic sheeting (builders' rolls) are a great way to protect large surface areas during painting or decorating, whilst layflat tubing (poly tubing) provides a great way of packing awkwardly-shaped items. Just place your product inside the tube, cut to the required length and seal.
- Specialist bags
- Whatever job you do and however specific your task, if you need a polythene bag to get the job done, then Polybags is the place to go. They manufacture a huge range of specialist bags, from asbestos and clinical waste bags to extra-strong Polymax sacks, along with a range of specialist food bags, including film-front window display bags and woven polypropylene sacks.
- Waste bags and sacks
- Polybags produces a massive range of waste bags and sacks to cater for every waste disposal need, whether in home, garden or workplace. Whether you want to recycle, compost, shred or compact your waste then look no further - head on over to Polybags and waste no more time in looking for waste bags.
Shrink wrap systems
Want to learn about the different types of shrink wrap systems? Well you've come to the right place. Here are the most popular kinds of shrink wrap systems available today.
Straight bar sealers - A straight bar cuts and seals the film manually. For low volume applications.
L-bar sealers - An L-shaped bar used to cut and seal shrink film. Averages between 0-40 packages per minute, depending on automation level (e.g. manual, semi-automatic, automatic, automatic continuous). Also known as: impulse sealer, sealing system, sealing equipment, L-sealer, L bar sealer.
Sleeve wrappers - Designed to wrap trayed or loose collated items. Mainly used in shipping applications. These shrink wrap systems often replaces corrugated boxes and other types of packaging that are costly and need more space to use, store & dispose of. Also known as: shrink bundler, shrink wrapper, heat wrapper, sleeve shrink equipment, sleeving system.
Form fill seal shrink wrap equipment - The ultimate shrink wrapper, designed for high speed shrink packaging applications, averages between 30 -100 packages per minute on a continual basis. Most applications use polyolefin shrink film / industrial shrink wrap film.
Heat shrink wrap systems
Shrink tunnels - The final step in shrink wrapping. Package is passed through the shrink tunnel. Once inside the zone of the tunnel, it is subjected to increased levels of heat and turbulent air flow. A quality tunnel is capable of producing the required amounts of heat and air flow to cause the film to shrink around the introduced package. Also known as: heat tunnel, shrink film tunnel, shrink wrap tunnel and shrink heat tunnel.
Heat guns - Hand held tools that blow hot air to manually shrink film. Low volume output.
Shrink film sealing systems
Until recently, most sealing systems used a hot wire in order to seal and cut-off the film at the same time; now, a knife system has gained in popularity on many models due to its durability.
The wire or knife seals the film against a pad, covered with Teflon tape to protect the pad. Time, temperature and pressure are the three most critical elements affecting the seal quality. If the sealing head is not held on the film long enough, the temperature is too low, or the pressure is insufficient or uneven, the seal quality will be poor and/or won't cut.
However, if the sealing temperature is too high, the film may break just behind the seal. Following the impulse-sealing cycle, a cooling cycle allows the film to solidify into a solid seal. This dwell-time is critical in order for a seal to hold.
PVC films require only heat in order to cut seal and cut. When run on a sealing system as previously described, buildup of carbon char (black specks and flakes) will occur. This needs to be cleaned from the sealing head on a regular basis, otherwise the carbon will interfere with the sealing process and will look unsightly on the sealed ends of the package.
Since only heat is needed to form a PVC seal, some machines use a hollowed out bottom plate instead of the foam pad; direct contact with the seal wire is eliminated. Other systems employ a much thinner nichrome wire (.020" diameter vs. a standard .036" to .040" for polyolefins) against a hard bottom sealing pad. This system is insufficient to create strong polyolefin seals.
One other sealing system designed for PVCs is called a universal sealing system. Despite the name, the hot knife is typically too sharp to form a quality polyolefin seal. A rounded knife is better suited.
Shrink film shrinking systems
In order for proper shrinking to take place, polyolefin films need an air evacuation hole or multiple perforations. A bag formed with PVC film does not need 'artificially created' air escape holes. Because of the make-up of PVC, the seal typically is full of small pinholes; this is where the air escapes during the shrinking process. While this may seem advantageous (a step can be eliminated), the small holes actually weaken the seal area. These holes are often located near or in the package corners.
In order for proper shrinkage to occur, polyolefin film must be exposed to the correct temperature for the correct amount of time (which is controlled by conveyor speed), and also be surrounded by the correct air velocity, or wind turbulence. The air allows the film to stand away from the product, and a 'bubble' is formed around it. A good, even shrink should result when this occurs.
PVC films shrink readily when exposed to heat, and therefore air velocity is not critical. In the marketplace there are low-end tunnels which have no settings to control air velocity (similar to an oven) and you may find it difficult to achieve a good shrink.