Polythene film manufacturing Polythene film manufacturing

Polythene Film Manufacturing

Polybags is the UK's number one polythene manufacturer.

We produce all of our own polythene packaging on site in our 50,000 sq ft factory, operating 13 blown-film extruders to make the polythene and 12 converting machines to turn it into the huge range of bags and sheets that our customers need.

Polythene extrusion lines work best when they run continually, so we operate 24-hour production to ensure that the quality of your products is first rate. This round-the-clock operation also improves production capacity, allowing us to manufacture and dispatch over 80 tonnes of quality polythene packaging products every week.

What's more, 24-hour production helps us keep costs down and provides us with the flexibility to prioritise key jobs, so your order is not only at rock-bottom price but our lead times are the best in the business.

With Polybags, you can guarantee you'll be getting the best value products on the market. There is a lot of polythene packaging to choose from so, if you are new to the manufacturing process, or just interested in how things are made, our handy guide (below) will give you an good idea of what we produce, how we produce it and the various options available to you.

Of course, you don't need to learn any of this unless you want to. You can always leave the manufacturing side to us and you just choose the product you require. If you have any questions the Polybags customer service team are always on hand to help, so please get in touch.

The polythene manufacturing process The polythene manufacturing process

The polythene manufacturing process

At Polybags we make our polythene packaging through the process of blown film extrusion - one of the most common manufacturing methods, in which an extruder heats and inflates raw polymer like a tubular balloon before cooling and flattening it ready for conversion into a huge range of plastic film or bags.

The diagram below gives an overview of the polythene extrusion process, which we will outline for you here.

Silo-fed raw material

The production of plastic film and bags begins with the raw materials used - granules or pellets of polyethylene, so how these are handled is a fundamental part of the process.

Polybags has eight huge external silos which each store up to 60 tonnes of these raw materials until the extrusion process begins as they are fed from the storage silos into the extruder. The advantages of this method include:

Polythene production chain Polythene production chain

The extruder

The raw polythene materials are fed via a hopper into the extruder - a machine with a long horizontally-mounted barrel 20-30 times as long as its diameter, which contains an Archimedes screw turned by a large electric motor and is heated as it moves.

As the raw material is forced through the barrel via the screw it is melted by both the heater elements and the action of the screw. Once it reaches the end of the barrel, the molten polythene is pushed through some gauze filters and then upwards into the extruder die - which contains 2 circular steel pipes placed one inside the other with a gap of 1mm at the exit.

The polythene exits the die in a circular tube and - aided by a set of nip-rollers drawn up a tower reaching several metres above - forms a tall tubular bubble with the die at the base. Air is forced into the bubble until it reaches the required diameter whilst, at the same time, a high-speed air ring blows cold air onto the polythene to cool it down.

The film continues to cool as it is drawn up the tower, before passing through the nip rollers at the top, which flatten the polythene tube to create a layflat tube. This is then drawn through a series of rollers back down the extrusion tower, during which process it may pass through a treatment point and a printer, which can customise your polythene - most frequently when making bags - with your very own company logo or design.

At this stage, the polythene can be kept in the form of a layflat tube or it can be slit on one or both edges to produce various types of plastic sheeting products (see below). These are all wound onto a roll around a cardboard core ready for dispatch.

Polythene film products Polythene film products

Polythene film products

The layflat tube of polythene that exits the blown film extruder provides versatility as, depending on how it is cut, it can be turned into a range of polythene film products.

The diagram below provides an overview of the main polythene film products available from Polybags, which we will provide further detail on here.

Polythene sheeting Polythene sheeting

As well as these various types of polythene film, the layflat tubing that is created during the extrusion process can also be converted into a range of polythene bags. See our page on polythene bag manufacturing for more information.

What people in the street might say about polythene

Black polythene suppliers bags are often chosen for waste concealment, nevertheless in trade terms the material does far above conceal what is inside. The dark pigment blocks light, which can assist with privacy, odour control and keeping contents less visible amid storage or assortment, yet the same colour also makes inspection harder if a bag requirements checking for damage or pollution. In warehousing and back-of-house handling, that matters because torn bags, weak seams and overfilled sacks can lead to leakage and messy manual handling. The gauge has to suit the load, or the bag will fail at the worst moment. A superb bag gives simple, proper containment; a poor one creates additional labour and avoidable handling damage.

Perforated polythene suppliers bags can assist fruit stay saleable for longer by balancing moisture loss against air movement. The holes stop the pack becoming a damp, stale pocket where condensation encourages spoilage, while the film still gives the manufacture a protected environment in cool storage. Bag gauge matters as well, because a 100-gauge film is robust enough to survive handling without turning flimsy on the pallet. When the fruit is waxed first, the pack works as part of a controlled storage system rather than only a cover, so shelf life improves and rejects are reduced.

packaging manufacturers suppliers Bags

packaging manufacturers suppliers bags do above transport a emblem, because the print has to survive filling, sealing, stacking and distribution without looking tired or unreadable. A superb bag requirements the proper film gauge, decent ink stickiness and enough film tension through the converting line so the design stays sharp instead of stretching or smudging. Thin film may save material, nevertheless it can wrinkle, split at the seal, or display scuffing when cartons are moved through a warehouse or loaded for consignment. The optimal selection balances appearance with handling strength, so the bag still does its job after the shop floor has finished with it.

bag manufacturers Extra-Strong Peel and Seal polythene suppliers Envelopes Opaque Review

polythene suppliers envelopes earn their place in computer packing when toughness and privacy matter at the same time. A robust opaque film conceals the contents from view, which is useful for dispatching documents, accessories, or boxed items that should not be seen in transit, while the peel-and-seal strip retains closure fast on a busy packing line. If the gauge is proper, the envelope resists splitting at the corners and survives the rough handling that happens in cages, sacks, and vehicle loads. A high rating normally reflects that sort of practical performance rather than appearance alone, and that is what gives a packing team confidence in daily use.

Big polythene suppliers bags can be used for above simple storage, nevertheless when they are left unlabelled and dumped into normal waste, they become a handling problem rather than a packaging solution. A big gauge bag will grasp a heavy, strange load well enough, particularly if it is tied off with thread or cord, yet that same bag offers small protection if the contents need traceability, controlled disposal, or secure movement through a busy site. In a warehouse, products that cannot be identified fast slow down sorting and raise the risk of the gross item being sent for recycling or destruction. Grossly mixed waste also makes stock control and audit trails harder to maintain. A bag only does its job properly when its purpose is transparent from the beginning.

Large polythene suppliers bags are often chosen for messy or awkward contents because they can grasp bulk material securely and retain handling straightforward, nevertheless the quality of the bag and the method it is closed make all the contrast. A heavy-gauge bag gives better puncture resistance and reduces the risk of split seams when the load is strange or has sharp edges, while a poor seal can lead to pollution, leakage, or problems amid transport and storage. In warehousing and dispatch, awkward consignments need transparent identification and controlled handling so they do not become a safety issue or a waste problem. A bag may seem like a simple item, yet the gross spec fast creates damage, delays, and additional clean-up.

A polythene suppliers mailing bag is often the smartest selection when products need light protection without adding dead weight to a consignment. For products that must stay dry, the film gives a simple barrier against rain, damp yards and rough handling in transit, while still keeping postage down because there is small additional bulk. The bags also suit printed presentation well, since a tidy outer can assist a package see cared for when it reaches the client. That said, the spec still requirements checking for gauge, seal strength and tear resistance, because a weak bag can fail at the gross point in the journey. When the product inside carries proper value or sentiment, clean arrival is the normal that matters.

Ampac Super Strong polythene suppliers Envelope 335 C3 Pk 100 - KSV-SS3

A tear-resistant polythene suppliers envelope gives better protection in dispatch because it stands up to rough handling far better than lightweight paper mailers or flimsy film bags. The opaque stop assists conceal contents from view, which matters when packets transport through busy sorting areas or shared storage. A peel-and-seal closure also speeds packing and gives a cleaner seal than loose tape, reducing the chance of items slipping out amid transit. The DX size offers useful room for larger flat products without forcing them into a tight fit, which can stress corners and increase damage. A pack of 100 suits normal despatch work and retains stock easy to manage on the packing bench. When a mailer combines strength, privacy and fast closing, it makes daily packing far less troublesome.

Biodegradable polythene suppliers bags need to be specified with care because their behaviour relies on both how they are manufactured and where they stop up after use. A correctly formulated film can still give the same daily handling strength as normal polythene suppliers on the shop floor, while the additive assists the material smash down more readily in landfill conditions when the bag is discarded. That makes them useful for shopping counters and delicatessens where light, hygienic carrier and manufacture packing is needed, nevertheless the waste route still has to be understood. If the bag is collected in a recycling stream, it may still have a second life, yet mixed or contaminated waste will change the outcome. Clear sorting and superb stock control stop the gross material being sent to the gross place.

polythene suppliers UK's continued sponsorship points to a simple packaging truth: visibility in the market can matter as much as the product on the floor. When a name is attached to a club or event, it is being handled like any other trade emblem, with the same need for recognition, consistency and long-term association. That sort of presence can assist a packaging business stay familiar to buyers, suppliers and warehouse teams alike, which is useful in a sectour where plenty firms seem interchangeable at first glance. Backing the same partnership above time recommends confidence rather than a one-off gesture, and that can transport more weight than a loud announcement.

Layflat tubing Layflat tubing

Types of polythene film

As the UK's number one manufacturer, Polybags can not only offer the range of polythene film products listed above, but we also offer a huge range of sizes, thicknesses and types of polythene film to meet your exact needs.

We can manufacture film from as narrow as 25mm (1") to as wide as 1.4m (55") and varying in thickness from thin 20 micron (80 gauge) film in special high melt films, through to 250 micron (1,000 gauge) heavy-duty films.

Our main types of film are listed below but please note that all film is available in a wide range of grades and colours and with blends and additives to order.

We take bespoke requests and manufacture film to a huge range of specifications so, if you have particular requirements for your polythene film, then please get in touch.

Standard Melt 2 Low Density Polythene (LDPE) - Polybags' standard film blend produces products that are easy to open or handle and are food-grade approved. Contains both an anti-blocking agent and a slip agent to help during the extrusion process. Used for: General packaging applications

High Melt 4 Low Density Polythene (LDPE) - This soft and flexible film has limited strength properties, which makes it perfect for light-duty applications and means we can produce our very thinnest films - as slender as 20 micron (80 gauge) thick. This allows us to save on the amount of film used in production, thus keeping costs down for the customer. Used for: Garment film and dust covers

Garment covers Garment covers

Low Slip Melt 1 Low Density Polythene (LDPE) - Less slippy than standard LDPE film, this blend is useful for making heavy-duty sacks and other products that will be stacked. Its higher molecular strength also makes it suitable for shrink applications. By expanding the film whilst still molten and then quickly solidifying it, the polythene structure means it contracts when heated by shrink gun or heat tunnel. Used for: Shrink films and sack applications

High Tensile Films - This blend of polymers, which include Medium Density Polythene (MDPE), provide the maximum strength to thickness ratio - i.e. films that are both strong but thin. High tensile films have a rough, crinkly feel with reduced clarity and flexibility, but the material is ideal for thin food-grade tint sheets and other tinted or coloured films. Used for: Food bags and food sheeting

Electroconductive Blends - This electrically-conductive film is designed to protect electronic components which may be sensitive to static electricity. A blend of highly-conductive carbon and Low Density Polythene (LDPE), these products can be used for everything from protecting electrical devices to storing explosive devices. Used for: Protective antistatic packaging

Metallocene Blends - Films produced with metallocene - polyethylene raw material manufactured using a metallocene catalyst - are strong and of very high clarity. The films are more expensive than regular polythene due to the cost of manufacturing metallocene but, when you see the clarity of the finished product, you'll understand why. Used for: Premium high-clarity films

Reprocessed Films - Polythene produced with recycled raw material will not produce a product as high in quality as when using virgin polymer, but the resulting film offers an eco-friendly and low-cost packaging solution. Polybags recycles whatever raw material we can and we will always offer to extrude processed film when we can, although lack of supply is often our biggest problem. Used for: Low-cost and reduced-quality products

Biodegradable film Biodegradable film

Biodegradable Film - Polybags' wide range of eco-friendly packaging is made from biodegradable film with an additive blend which provides first oxidative and then biological degradation, typically within 6 - 24 months of being placed in compost or landfill. A fantastic green alternative to regular polythene, this cost-effective, strong and recyclable film offers a superior solution to many other eco-friendly products on the market. Used for: Food waste bags, dog poo bags and other compostable packaging solutions

Top ten common things said about polythene

Black polythene suppliers bags are often chosen for awkward or sensitive consignments because they retain contents out of sight, contain loose material, and give a tough barrier amid handling. In a warehouse or on a despatch bay, that sort of bag is often used for waste, contaminated returns, or mixed materials that should not be exposed before assortment. The key point is that the bag itself has to suit the job: gauge, seal strength, and puncture resistance all matter if the load may shift or grasp amid transit. A poor bag turns a routine transport into a handling problem, while the proper one retains the consignment contained and easier to manage.

Perforated polythene suppliers bags assist guava retain better at ambient temperatures because they slow moisture loss without trapping also much condensation around the fruit. That matters on the packing line and in storage, where sealed film can turn soft fruit into a sweating load that decays faster. The perforations enable a gentle exchange of air, so the pack stays less clammy and the fruit skin is less likely to smash down. Used with careful picking at the proper maturity, these bags can grasp fruit for several days in a warehouse or shopping chain, while unperforated film would often shorten shelf life through rot and handling damage. In practice, the bag design requirements to match the fruit's breathing and the journey it is likely to make.

Plain & packaging manufacturers suppliers Bags on the Roll Various sizes

packaging manufacturers suppliers bags on the roll sit in that unglamorous nevertheless highly engineered corner of packaging where line speed, film behaviour and stock discipline meet. The contrast between a plain roll and a dash of packaging manufacturers suppliers bags is not merely cosmetic; it introduces register control, ink stickiness, surface treatment and unwind consistency into a format that may be feeding a bench dispenser, an automated bagging station or a select-face operation with small tolerance for snagging. Gauge selection is often where the proper compromise is manufactured: also light, and puncture resistance suffers around sharp carton edges or metal components; also heavy, and the reel carries unnecessary tare weight, reducing volumetric efficiency and adding avoidable polymer to all consignment. A well-specified polythene suppliers film relies on stable melt-flow consistency, controlled slip and anti-block performance, with surface resistivity managed where static cling would otherwise turn secondary bagging into a slow, fiddly process. Print adds another layer of discipline, particularly where barcodes, handling labels or product identifiers must remain legible after rubbing against neighboring stock on a pallet. Mono-material building still matters, despite the added decoration, because downstream recyclability is far easier to maintain when inks, additives and film grades are selected with reprocessing in mind rather than treated as an afterthought. The result is a deceptively simple packaging format: compact in storage, fast at the packing bench, and technically dependent on micron-specific gauging, reel tension and polymer chemistry behaving exactly as specified.

polythene suppliers envelopes are often chosen when mail requirements a tougher outer skin than paper can give. The material resists scuffing and light moisture, so shopping packs, list of products inserts and promotional kits arrive with a cleaner face after sorting and transport. Colour also matters, because a well-matched envelope can assist a campaign see consistent from the dispatch bench to the receiver's desk. Even so, the proper gauge has to be chosen with care: also light and the bag can split at a weld or tear at the seal, also heavy and it wastes material and adds cost. A sound specification retains appearance, protection and handling in balance.

Big polythene suppliers bags are often the simplest method to retain loose belongings together when storage space is poor and conditions are rough. In this case, the bags did above grasp clothes and papers; they kept separate items dry, tied shut, and easy to transport without constant re-sorting. That kind of packing works because polythene suppliers bends around strange shapes and shrugs off light rain better than card or material. It also makes sense where possessions must be handled fast and carried by hand. The downside is apparant: once the bags split or the knots fail, the contents are exposed and mess spreads fast, so robust material selection and secure tying matter above appearance.

Large polythene suppliers bags are often the quickest method to transparent mixed waste from a busy site, nevertheless their proper value relies on how they are handled and what goes into them. On a hotel floor, that means selecting a bag gauge that can cope with sharp packaging offcuts, food waste, and normal debris without splitting before the load reaches the bin store. If staff occupy them also fast, the neck becomes hard to tie and the load shifts amid lifting, which creates handling damage and additional mess. A sensible waste routine retains the area tidy and reduces the risk of leaks or torn sacks on the method out. Good bag selection saves time only when the load is matched to the job.

An opaque grey polythene suppliers mailing bag gives a simple nevertheless proper method to transport products through packing, dispatch and delivery without drawing attention to the contents. The dark film conceals the product, which assists with security and also makes mixed consignments see tidy on the despatch bench. At 715 x 585mm, the size suits larger soft products or folded items that do not need a box, so there is less wasted null and less secondary packing to store. A pack of 250 also assists with stock rotation in busy rooms, where operatours need a proper supply and consistent bag quality to retain sealing, closure and handling damage below control.

A lightweight polythene suppliers envelope can cut mailing waste without giving up basic protection in transit. Clear film lets the contents be checked fast, which assists select-and-pack teams and reduces mistakes at dispatch, while the low gauge retains postage and handling weight down. Even so, the film still requirements enough toughness to resist splitting at seals, corners, and rough conveyour handling, because a damaged mailer can lead to returns, claims, and wasted stock. Choosing a recyclable envelope also makes disposal simpler at the client stop, provided local assortment systems accept the material. That balance of light weight, visibility, and practical strength makes sense where daily mailing requirements a tidy, low-risk pack.

Biodegradable polythene suppliers bags only transport proper value when the specification matches the job, because a bag that smashs down also fast can fail in storage, while one that is also heavy for the application wastes material and cost. For packing lines and shopping handling, that means checking gauge, seal quality and how the film behaves below load, not only whether it carries a green label. In a warehouse, poor bag selection can lead to split sacks, handling damage and additional secondary packing, all of which slows dispatch and creates mess at the select-face. If the aim is to cut persistent plastic without creating new problems, the bag has to suit the product, the route and the shelf life.

polythene suppliers UK's assist for a charity and community award shows how packaging firms often build their public profile through local involvement rather than flashy promotion. For a business linked to film, bags and protective wrap, that kind of sponsorship can sit well with the daily reality of supplying materials that retain products clean, secure and easier to handle through storage and transport. It also signals that a converter's reputation is not built only on machine output or gauge control, nevertheless on whether the company is seen as proper and well dash. That sort of visible backing can strengthen client confidence and staff pride at the same time, which tends to matter above a glossed-up brochure.

Film additives

Polybags can introduce a series of additives to the polythene manufacturing process, blending them during production to give your polythene film or bags the specific properties you need.

We have a huge range of additives that we can add - so contact us if you have any queries - but here are some of the most common requests: