Shrink film - heat-shrink and protect your product!
Welcome to Shrink-Film.co.uk - the UK's home of best quality shrink film and shrink wrap at fantastic discount prices.
We provide a range of shrink film products, including shrink wrap, shrink pallet covers and shrink pallet top sheets, along with shrink guns and complete shrink kits, to cater for any job where a shrink-wrapping solution is required.
As well as providing you with the cheapest shrink wrap supplies, courtesy of our parent website Polybags.co.uk - the UK's number one polythene manufacturer - we bring you an excellent online resource on everything to do with shrink packaging.
You'll find information on what shrink film is, how it is made, different types of shrink film, applications of shrink film and much more, including our buying tips to help you save money on your shrink film purchase.
What is shrink film?
Shrink film, or shrink wrap, is plastic that is heat-sealed around an object or item being packaged. Once the item is loosely wrapped in shrink film, heat is applied all over the plastic from a heat gun or a heat tunnel. The plastic has additives that allow it to shrink when heat is applied, causing it to form a tight layer around the product to complete the wrapping process.
Site contents - find out all you need to know about shrink film
Buy shrink wrap film
If you want to buy Shrink Wrap Film and Shrink Bags then you've come to the right place!
Shrink-Film.co.uk is a division of Polybags Limited - the UK's leading manufacturer and suppliers of polythene bags, shrink film and packaging products. We supply PVC shrink film, polythene shrink film or polythene shrink bags and poly bags of all kinds. Featuring some of the lowest prices online and fast, free UK delivery, make sure you order today and save!
Options in shrink packaging
These are the most available packaging options for shrink packing today:
Shrink film - comes in two basic varieties: single-wound (flat) and centerfold.
Shrink tubing - essentially the same as centerfold shrink film, except that the non-folded side is sealed to create a tube.
Shrink bags - again very similar to shrink film, but sealed on three sides to form a bag in which to place the product.
Detailed information on shrink wrap films
Shrink wrap films are the most popular and inexpensive materials used for packing. Nowadays, shrink wrap films are available in a variety of models and sizes. Commonly-used types include polyethylene shrink film, PVC shrink film and polyolefin shrink wrap. They pack products such as boxes, tapes, CDs, food, DVDs, jewellery boxes, photographs and frames.
PVC shrink films are used for packing non-perishable items, and are available in eye-catching colors. This type of film will shrink at low heat. Though PVC shrink film is approved by the US Food and Drug Administration (FDA) for food packing, it has a pungent odor.
Polyolefin shrink wrap film is a combination of polyethylene and polyethylene. It is more transparent and smoother than PVC shrink film. It usually requires high temperatures to shrink, but also works well with one step shrink wrap machines. Polyolefin shrink wrap films are more commonly-used for packing food products and are available in different forms, including low-temp polyolefin, anti-fog polyolefin and pre-perforated polyolefin.
A general-purpose shrink film, the polyethylene shrink film is well known for its versatile nature. It can also withstand bad climatic conditions, so it is used to wrap large items such as boats and cars during the winter. Polyethylene shrink films mostly come with UVI protection to avoid damages caused by ultraviolet rays. EVA (Ethyl Vinyl Acetate) is added with polyethylene shrink films to keep them soft and flexible in winter. This heavy duty shrink film is available in eye-catching colors and attractive prints.
All types of shrink wrap films come primarily in two varieties: single-wound and centerfold. In centerfold shrink wrap films, the products are tucked in between the fold of the films, and then the edges are sealed. But in single-wound shrink wrap film, one layer of film is wound around a core. This kind of shrink wrap film is widely used for packing automatic equipment. The centerfold shrink wrap film is meant for semi-automatic and manual shrink packaging.
Shrink films are available in different widths and gauges - mostly in 60, 75, and 100 gauge, with a width above 10 inches. Generally, prices depend on the length, width, and qualities such as the shine and clarity. PVC shrink films are the cheapest of the lot. Shrink films can be availed from any of the local outlets or online stores specialising in the same. The main advantage of online stores is that they provide a wide array of options.
Shrink film materials
Generally there are three major types of shrink over wrap films:
- PVC low temperature shrink film which can be shrunk using either a hand-held heat gun or a conveyorized heat tunnel.
- Polyolefin shrink film which requires a higher heat to shrink it must use a conveyorized heat shrink tunnel.
- Polyethylene (PE) in the form of low density polythene (LDPE) is the best suited for general shrink wrap packaging. This is because it is relatively strong, inexpensive and has a good shrink ration.
Manual and semi-automatic shrink wrap machines use center-folded shrink film. Automatic machines can use either center-folded shrink film or flat single wound sheeting on rolls.
Types of shrink film
- Light gauge shrink film
- Light force shrink film
- High speed shrink film
- Anti-fog shrink film
- High slip shrink film
- Perforated and ventilated shrink film
How shrink wrapping works
Do you know how shrink wrapping works? Find out here.
The shrink wrapping process begins by enclosing a product in shrink film or a shrink bag. The film or bag is formed around the product using a sealer. The product is then heated so that the shrink film or shrink bag shrinks around it to create a tight, sealed package. This process mainly consists of two steps:
Step 1: Shrink film is wrapped around the items to form a pack;
Step 2: The film wrap is shrunk using a shrink tunnel and the wrapped items allowed to cool. The film strengthens, shrinks further and tightens around the items.
When it comes to shrink wrapping items, there are two main methods of wrapping employed:
Sleeve Wrapping - ideal for regular-shaped products that can be collated to form packs for palletising, warehousing or distribution. Sleeve wrapping is easily automated. It uses two rolls of flat sheet shrink film. A welding bar is used to weld the ends of the PE sheets. Note that the resultant pack is not totally enclosed because of the sleeve open ends.
Over Wrapping - achieves a total enclosure of the product through a perimeter-sealing process, performed on L-bar type machines that utilise centre-folded film. Total enclosure can also be achieved using flat sheet film on a flow-wrapping machine. Over wrapping suits flat rectangular products such as magazines and CDs. When performed on an L-bar sealing machine, the end of the film is sealed across the width and forms one of the sealed sides of the pack. The product is inserted between the layers of film and then transferred together to the sealing station. Here the remaining two sides are sealed and the product is now completely enclosed by the film. From there the package is moved onto the shrink tunnel conveyor to complete the operation.
Benefits of shrink packaging
Using shrink packaging to package products has a number of advantages, some of which are outlined here. Shrink packaging:
- Enhances the look of the package
- Maintains product quality
- Blocks dust and dirt
- Is tamper-evident/resistant
- Is recyclable
Applications of shrink film / shrink wrapping
Shrink wrap is employed in a range of industries for a huge variety of products and purposes. Here are a few of the main ways that shrink film is employed in the market today.
Shrink wrap for printed materials - This is still the largest of all market segments. Once dominated by PVC films, the introduction of the low shrink force polyolefins has dramatically eroded the PVC-domination of this market. Businesses involved in this segment range from small job shop printers up to large business form producers. Gone are the days of contracting these jobs out, as most now perform the packaging within their own facilities.
Shrink wrap for toys, games and sporting goods - Shrink film is used here to assure product integrity and offer the consumer visual appeal. Plastic models, puzzles and games all benefit from the security of shrink film.
Shrink packaging for hardware and houseware - A broad category with a tremendous variety of product being overwrapped. From tools to plastic bowls, shrink wrap fulfills the need once served by corrugated and blister packaging.
Shrink wrap for packaged foods - Major applications include frozen pizza, ice cream and frozen foods. The fastest growing trend is the process of multi-packing products for sale at wholesale type stores. The use of shrink offers the benefits of enhanced visual appeal, tamper evidence and prolonged shelf life, through the prevention of freezer burn.
Shrink wrap for stationery, cards and gift wrap - PVC films are still widely used to protect these easily-damaged products and improve appearance. Today's soft shrink films afford the opportunity to introduce polyolefin films into this market.
Shrink wrap packaging for pharmaceuticals - Spurred by the need for tamper-evidence, this market has grown in recent years. Lower-cost alternatives (e.g. PVC shrink bands) control most of the individual product need, although shrink wrap offers the ability to reduce costs through multi-packing with film versus other packaging alternatives.
Shrink wrap for videos, DVDs and CDs - These products all benefit from some sort of film overwrap. Video is predominantly shrink-wrapped, whereas CDs are usually done with a non-shrink process such as tuck and fold. More and more CD producers have turned to shrink wrap as they are updating equipment.
Shrink wrapping is widely used across the spectrum of industries and is finding its way into new segments daily. The retail appeal and security offered insures growth for the future.
Shrink wrap sizing
Shrink wrap sizing - also known as package sizing - is the act of determining the appropriate size film for overwrapping of a specific package with shrink film.
Many factors must be considered when sizing the film requirements: (i) the actual product dimensions; (ii) the orientation of the package as it will introduce into the film and (iii) the type of equipment to be used. Failure to obtain this information or incorrect specifications may result in inappropriate film size being calculated.
Each package has three dimensions which must be known. These measurements should be made with the orientation (positioning) of the package as it enters the film identified:
Product width: The dimension of the product in the transverse (parallel to the cut-off or cross-seal) direction.
Product length: The dimension of the product in the machine (parallel to the fold of the film, in cases of centerfold film) direction.
Product height: The actual height of the product. In cases of products with uneven surfaces, the height should be considered from the bottom to the highest point of the package.
Product orientation: When measuring a product for film sizing, remember to use the longer dimension as the product width, bearing in mind it must not surpass the seal dimensions of the equipment being used.
There are numerous benefits to knowing the correct dimensions of your product and therefore being able to shrink wrap it correctly. These include:
Less shrink waste - By orienting the package using the shortest possible dimension as the product length results in the smallest amount of waste, in cases of centerfold use or side-seal applications.
Increased packaging speed - A shorter product length results in faster cycling of products into and out of the sealing area. Over the course of a production shift this incremental time saving can produce large dividends.
Increased film roll bag yield - Although a product requires the same square inches of film regardless of orientation, the amount of scrap produced is decreased.
Another consideration when recommending film size is production speed. In many cases, the formula to calculate required film size turns out not to be a whole number. Although half inch (½") increments are available, most users opt for a standard inch size (1”), usually rounding down in an attempt to save money. Many times this practice actually costs more than the cost had they rounded up and increased the film size. By trying to use the narrowest film size possible, users may actually make an operator's job more difficult, reducing production speed and increasing the overall package cost.
Once package orientation and dimensions are established, the next consideration is the type of equipment upon which the package is to be wrapped. Specific types of equipment dictate the use of either centerfolded or single-wound film. Furthermore, some types of machinery demand the use of wider film sizes than others due to the mechanics of their operation.
When using the film sizing formulas to calculate film sizes, be sure to use the formula for the type of equipment it is to be used on.
1. To calculate band or sleeve sizes, you need to calculate the layflat width and the cut length. To do this:
Layflat width = [Diameter (millimetres) + 2] x 1.57
e.g.: 100mm diameter + 2mm = 102mm x 1.57 = 160mm
2. To convert inches (“) to millimetres (mm):
25.4mm = 1”
e.g.: 5” x 25.4 = 127mm
3. To convert millimetres (mm) to inches (“):
1 inch / 25.4mm
e.g.: 127mm / 25.4 = 5”
4. To calculate the diameter when the circumference (distance around the product) is known:
Diameter = Circumference / 3.1416
e.g.: 300mm circumference / 3.1416 = 95.49mm diameter
Which shrink wrap film to use?
When sourcing a shrink wrap machine, the type of shrink film to be used should be considered to ensure system compatibility and application suitability.
There are three shrink wrap film supply categories:
PVC shrink film - PVC offers good optical and shrink characteristics. PVC film is very heat-sensitive and requires special handling and storage. The film's plasticisers, which are added during manufacturing, migrate with age which causes the film to become yellowish and brittle. PVC film is very temperature sensitive requiring special handling and storage. Exposure to freezing temperatures tends to cause films to split and shatter.
Polyolefin shrink film - Polyolefins is a generic term used to describe a family of polymers which include polyethylene and polypropylene. Co-extruded polyolefin shrink film is subject to official approval standards for direct contact with food.
Polyethylene shrink film - Polyethylene films tend to lack the optical properties and tight shrink characteristics needed for most shrink film applications. Polyethylene is predominantly used in the process of packaging known as bundling. Unlike other shrink films, polyethylene does not shrink at the presence of heat. Rather, it shrinks after exposure.
Points to consider buying shrink bags or shrink wrap film
Looking on the internet and finding the right supplier of your shrink wrap film or bags can be daunting. There are a number of points you should consider buying a quality shrink film at cheap prices, as detailed in the list below. Thankfully, as part of Polybags Ltd, we can offer you all of the following:
Lowest prices - Compare prices in the industry & save. Polybags offers the lowest price on custom shrink wrap film and bags. We're committed to offering you low prices, so we'd love to know if you found a better price for any bags at another retailer.
No minimum order - Choose a supplier who can offer you a low quantity purchase, like us!
100% satisfaction guarantee - If you order the wrong product or simply change your mind, you don't want any hassle when it comes to sending it back. That's why you should consider buying from Polybags, who offer a 100% no-quibbles guarantee.
Manufacture bags to your specifications - Not any supplier would have any size you need in stock, so choose a supplier who can make the shrink bags or film as per your need. Sound familiar?
Fastest turnaround time - If you are looking for custom-made bags and a quick turnaround time, choose a manufacturer like Polybags and not merchants. Cut out the middleman.
Free delivery - Calculate total cost of shrink film or shrink wrap film including delivery, because some retailer may sell cheap bags but charge an extra on delivery. Polybags provides fast, free delivery across the whole of the UK and Ireland (minimum spend may apply - see the delivery slide above for further details).
Free sample - If you are unsure about the shrink film you wish to buy - or any product for that matter - then request a free sample before you buy. Polybags offers this service at no obligation.
Shrink bag gift ideas
Have you thought about using shrink bags to wrap soap or candles to create a fabulous gift?
Besides holding the scent of your product, shrink bags also give your soap or candles that finished look, which will elevate them from standard household fare to a nice gift for a friend or loved one.
Shrink bags are easy to use - here's a simple guide on how to wrap your soap or candle to make a lovely gift:
- Shrink bags will reduce in size approximately 40% during the shrink-wrapping process, so make sure you have the right size shrink bag for your product
- If your bag is too long before shrinking, just cut some off
- Place your item inside the shrink bag
- Fold the bag over and seal with clear tape or just hold the end shut
- Use a hair dryer or heat gun to shrink the bag around the item
- The slower you shrink, the smoother finished product you will have
- Be patient; it is better to shrink on lower heat
- If too much air stays in the bag, use a pin and make a small hole for the air to escape
- An adjustable heat gun is a great investment to produce wonderful results. Practice makes perfect
- As an alternative to shrink bags, you could use cello bags, which are coated to hold in smell. Cello bags do not shrink but can be sealed shut
- Never put your soap or candles in poly or kitchen zip bags, as these will not protect the scent.
Reference: eBay guides
Shrink film terms
This handy guide will help you learn different terms you might come across whilst shopping for or using shrink wrap and film:
- Angel hair - Thin strands of film appearing at the cut end of film resulting from sealing.
- Ballooning - A pillow effect created when air is trapped within the shrinking bag.
- Bead seal - A thin round weld created when pressure and heat are applied to two layers of film.
- Bi-axial orientation - Oriented along both X and Y-axis.
- Blocking - A condition in which two layers of film adhere to one another.
- Blown film - A film extruded by air inflation, e.g. blown stretch film such as blown hand stretch film
- Burn through - A temperature or condition where a film becomes cloudy or burns in the shrink tunnel.
- Centerfold film - Film that has been folded in half, lengthwise.
- Centerfolder - A mechanical device used to create center-folded film.
- Coextrusion - Two or more polymers extruded and combined in a die, each forming a distinct layer in the final film.
- Cold slip - The amount of force required to slide two surfaces against one another at ambient temperature.
- Cold flex (CF) - Ability of a film to perform at low temperatures without failure.
- Copolymer - Result of two monomers being combined through polymerization.
- Core - A paper tube on which film is wound (see pic above).
- Cross-linking - A process which binds the polymer chains into a network, significantly increasing a film's heat stability and strength.
- Crow's feet - A series of wrinkles radiating out from a finished package's corners.
- Dog-ears - Triangular projections of unshrunk film at the corners of finished packages.
- Drape - The softness of a film characterized by the ability to conform to irregular shapes.
- Electron beam - A device used in the cross-linking process.
- Fish eyes - A scalloped surface on a finished product surface.
- Form-fill-seal - A type of equipment which produces a tube of film into which packages are introduced.
- Gauge - A term used to describe the thickness of a material such as shrink film / shrink wrap or stretch film / stretch wrap or pallet wrap, e.g. 100 gauge shrink film, 60 gauge stretch film, 70 gauge pallet wrap.
- Hole punch - A mechanical device used to produce an air evacuation hole.
- Hot slip - The amount of force required to side two surfaces of heated film against one another.
- Impulse seal - A heat sealing technique where the element is pulsed with voltage during the sealing cycle.
- L-Sealer - A term used to describe equipment where the seal area is in the shape of the letter 'L'.
- Laminate - A general term used to describe structures comprised of two or more materials.
- Lap seal - A seal made with two layers of film overlapping one another.
- Machinability - The ability to form and seal on overwrapping equipment.
- Machine Direction (MD) - The direction the film is manufactured and moves through the sealing equipment.
- Memory - The ability of a film to maintain its characteristics after shrinking.
- Monoaxial - A film which is oriented to shrink in only one direction.
- Monolayer film - A single layer film extruded from one or a blend of raw materials.
- Multilayer film - A film comprised of more than one layer of similar or different polymers.
- Opaque - Relatively impervious to light, e.g. opaque white stretch film; opaque black stretch film (stretch wrap)
- Optics - The visual properties of a film.
- Orientation - The stretching technique used in the manufacturing of film.
- Oriented - The stretching and aligning of a film's molecules at a temperature below its melting point.
- Perforations - Air evacuation holes in a film made by pin perforators.
- Pin perforators - A device used to produce small holes in film to allow air to escape during the shrinking process.
- Polyethylene - A simple thermoplastic polymer of ethylene.
- Polymer - A material made through the process of polymerisation.
- Polymerisation - A gas heated under pressure forms a solid.
- Polyolefin - A generic term used to describe ethylene and/or propylene based plastics.
- Polypropylene - A thermoplastic polymer of propylene.
- Preferential shrink - The characteristics of a film to shrink more or less in a specific direction.
- PVC - Polyvinyl chloride. Also a type of shrink film.
- Seal wire - An element made from nichrome wire used to seal film.
- Selvage - Another term for trim waste.
- Shrink - Defined as the ability to become smaller.
- Shrink tunnel - A type of equipment featuring a chamber producing heat and airflow designed to shrink film.
- Shrink Tubing - Similar to centerfold film, except the non-folded side is sealed to create a tube.
- Shrink Bags - A film that is sealed on three sides to form a bag in which to place product.
- Single-wound film (SW) - A single layer of shrink film wrapped around a core. Also called flat film and is used in high speed production (ex: automatic form/fill/seal).
- Slip - The quality of a film to move over surfaces with little resistance.
- Static - An electrical charge built-up in plastic film.
- Static seal - A type of longitudinal seal used in FFS equipment. Overlapping film edges are adhered to one another via a static charge.
- Tap switch - An electrical device used to control the amount of voltage introduced to sealing elements.
- Tear initiation - The amount of force required to initiate a tear.
- Tear resistance - The ability of a film to resist the propagation of a tear.
- Transverse Direction (TD) - The direction parallel to the film width.
- Trim - The amount of excess film severed during the sealing process.
- Trim seal - A seal made by using a sealing wire element.
- Unbalanced - Unequal orientation in the LD and TD.
- Wind - The direction in which the film or shrink film is wound on the core.
For more detailed information on poly tubing and sheeting, plastic bags or any kind of polythene packaging, please visit PackagingKnowledge.com.
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