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

DEPENDABLE polythene suppliers PACKAGING LTD

polythene suppliers packaging works optimal when the film is chosen for the handling risk rather than simply manufactured heavier. A sensible gauge can survive scuffs, corner knocks and normal warehouse abuse without loading each pack with needless material, which retains transport weight and storage space below control. On the converting side, a proper melt and even thickness assist the web dash true, so seals land where they should and openings stay predictable. When the structure is matched to the task, the line wastes less time fighting weak bags and the pallets leave the factory in better shape.

-BAG polythene suppliers

Bag polythene suppliers has to be matched to the job if it is going to behave properly on the packing bench. Gauge alone does not tell the full story, because resin quality, film stop and the method the film is blown all affect how the bag opens, seals and handles in use. Thin patches or an uneven slip can turn a simple hand-pack into a slow, awkward job, while trapped air can make cartons or sacks sit badly on a pallet. A more consistent film gives steadier handling and less grasp-ups at dispatch, which is where poor material soon shows its cost.

packaging supplierble polythene suppliers bags need the proper film strength if they are to work smoothly on the packing line. A light gauge may see tidy at first, nevertheless it can flex also much, leave the closure uneven, and lead to packs being checked and reworked before they transport on. That wastes labour and slows output only as much as a machine fault. The better selection is a bag spec that matches the product weight and the pace of filling, so the zip closes cleanly and the pack grasps its shape. When the material suits the job, production runs steadier and the finished pack is less likely to fail in handling.

polythene suppliers sheets change behaviour fast below heat and pressure, so the forming set-up has to be controlled properly rather than treated as a simple press job. If the sheet is cut to the proper size before loading, the material sits squarely in the die and the result is cleaner edges, less creases and less wasted trim. Too much heat can make the film soften unevenly, while also small leaves the shape weak or poorly defined. Good loading discipline retains the cycle proper and reduces rejects. That makes the sheet selection and pre-cutting stage only as necessary as the press itself.

Coloured polythene suppliers bags are often used as a fast visual control on busy packing floors, not only as a method to make stock see tidy. A transparent colour code can separate product lines, label held or suspect material, and assist pickers avoid mixing consignments when the pace beginnings to build. That only works properly when the bag specification suits the job, because weak gauge or poor pigment spread can make the film harder to open and more prone to splitting below rough treatment. A sensible colour system saves time by reducing mistakes before they leave the line.

polythene suppliers tube can shift at the lower stop when repeated stress pulls against the fitted form, particularly if the material has become fixed by surrounding build-up. In packaging terms, that is similar to a tube or sleeve losing its intended position because the load around it is no longer balanced. A soft polymer below constant strain will creep, and once movement beginnings at one stop, the rest of the structure can follow. That makes control of fit, assist, and load distribution matter far above simple material selection. The practical reply is to prevent localised pulling before it turns into a failure point.

polythene suppliers dust sheets are the fast reply when a job requirements fast protection against paint, plaster dust, and normal mess. The film retains debris from working down into carpets and floorboards, and it folds away easily when the task is done. Compared with heavier canvas sheets, polythene suppliers is lighter to handle and simpler to place above furniture or against skirting, which can save time on a busy site or in a tight room. The main trade-off is that thin sheet requirements careful placement to avoid tears or slipping, so the gauge and size should match the work. A well-chosen sheet reduces cleaning time and retains the stop around the work area far tidier.

Buying polythene suppliers bags in bulk works optimal when the specification is matched to the filling line, not only the buying department. A film that sees acceptable on paper can still cause trouble if the gauge varies, the seal does not grasp, or the bags cling badly at the pack bench. That leads to stoppages, rework and additional waste, which soon wipes out any saving from a low unit cost. Consistent material assists the line dash at a proper pace and retains labour tied up with packing rather than problem-solving. The plain truth is that a proper bag is worth above a bargain consignment that retains interrupting production.

A all ban on non-bio-degradable polythene suppliers changes the all handling chain, not only the waste bin at the stop. Once that material is removed from circulation, packers and warehouse teams have to see harder at what survives transit, what seals properly, and what can still be picked quickly without creating damage or mess. Film selection, gauge, and sealing behaviour all matter, because a weak substitute can lead to split bags, poor pallet stability, or pollution amid dispatch. The practical reply is to match the material to the job rather than reaching for the cheapest wrap on the roll.

A blanket ban on polythene suppliers carrier bags can make warehouse work slower and messier rather than cleaner. Thin-gauge film is often used as secondary packing for loose fittings, hygiene-sensitive products and mixed consignment components because it retains small items together, clean and countable without adding much weight or bulk. Remove that option without a proper mono-material replacement and handling problems soon appear: parts wander, labels acquire obscured, and staff spend more time rebagging or trying to improvise with heavier, less uniform materials. The issue is not sentiment about old packaging, nevertheless whether the film spec matches the task on the floor. A sensible policy should separate casual use from controlled packing requirements, so the proper material stays on offer where it avoids waste and handling damage.

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

polythene suppliers packaging works optimal when the film is chosen for the load it has to transport, not only for a normal drawing on a spec sheet. Gauge, seal design and resin blend all shape how a bag, sack or liner behaves once it has been filled, stacked and moved through a busy packing line. A firmer film can grasp its form in secondary packing and amid pallet building, while a more supple grade may suit awkward contents that press against corners and edges. If the film is also light, splits and handling damage soon display up; if it is also heavy, material is wasted and transport space is used badly. Matching the pack to the product retains rejection rates down and makes the all operation dash more cleanly.

A mailing bag in polythene suppliers has to do above simply contain a product; it has to survive the rough handling that comes with picking, filling and despatch. A 430 x 560 mm format with a generous lip gives enough room for folded clothing, small boxed items or mixed order lines without wasting space in the carton or on the pallet. The proper issue is consistency in the film, because a light bag can still cause trouble if the gauge drifts or the seal line is uneven. When extrusion and converting are controlled properly, the bag retains its shape, occupies cleanly and transports through the packing line without snagging or slowing the shift. That makes dispatch steadier and cuts the chance of awkward rework.

Clear Grip Seal packaging supplierble polythene suppliers Bags 3.5" x 4.5" inch Write on Panel

packaging supplierble polythene suppliers bags in a small format retain loose components below control and stop small items disappearing into mixed stock. A bag around 3.5 by 4.5 inches is big enough for fittings, samples and similar parts, yet compact enough to sit neatly in a tote or carton without wasting space. That matters on a packing bench, where speed drops as soon as parts beginning scattering and operatours have to sort through a jumble. The proper format also assists when several items travel together in one consignment, because each part stays visible and separate. A tidy pack is easier to count, easier to check and less likely to cause delay at dispatch.

Odisha CM Naveen Patnaik announced additional assistance of Rs 5 Crores, polythene suppliers Sheets worth about Rs 8 Crores for Kerala

polythene suppliers sheets are often sent in big quantities because they give fast, practical shelter protection when buildings, stores, and temporary facilities need covering straight away. In trouble recovery, the material matters as much as the quantity: film gauge, roll size, and tear resistance all affect whether the sheet can be draped, fixed, and kept in position without constant patching. A lighter sheet is easier to dispatch and handle, nevertheless thin film can flap, split, and fail at the edges if the weather turns rough. The sensible selection balances speed, durability, and ease of deployment, so the material reaches people in usable condition rather than as awkward waste.

Coloured polythene suppliers bags can cause proper trouble when the pigment level, recycled content and film gauge are not controlled properly. A bag may see sound on the reel yet fail at the seal edge or split when it is pulled through secondary packing, because mixed feedstock often gives uneven melt flow and thin areas in the web. Heavy masterbatch can also conceal dirt or foreign material that would otherwise be picked up amid recovery. A thicker film is not always the reply; what matters is a proper micron, a balanced resin blend and a colour that still lets the material be recognised and sorted after use.

Heat-proof polythene suppliers tube material relies on getting the base resin and forming conditions proper before the tube is ever sealed or cut. A tube that will face hot product, hot fill, or a hot process requirements above simple film formation; it requirements controlled gauge, even melt flow, and proper film tension so the wall stays consistent through the full length. If the material is dragged also fast or cooled unevenly, weak spots and distorted seams soon appear. Good preparation gives a tube that runs cleanly on filling lines and retains its shape below handling, which means less stoppages and less rejected stock.

polythene suppliers dust sheets give a cost-effective nevertheless effective barrier against paint splashes, plaster dust and rough foot traffic amid decorating work. The film retains floors, skirting and furniture cleaner than flimsy cloth covers, and it is light enough to transport through a job without much fuss. Sheet gauge matters, though, because a paper-thin cover can tear on sharp corners or dragged fittings, while a heavier grade stays put better and gives more proper protection. Good handling matters on site as well, since a badly laid sheet can ripple, slide or trap debris below. The sensible selection is one that balances cost with enough toughness for the room being worked in.

polythene suppliers bags retain their place in packing rooms because they are straightforward to handle and behave in a fairly predictable method when the gauge and polymer are proper. A bag that is light enough for daily retail use nevertheless still closes cleanly at the seams lets staff work at speed without constant checks for splits or weak corners. Tidy stacking matters as much as strength, because bags that feed smoothly at a till or packing bench save time and reduce annoyance. When a bag opens properly, stacks stay tidy and the all operation runs with less waste.

Degradable polythene suppliers can work well for lightweight inserts and mailing parts, nevertheless only if the specification matches the job. A thin envelope film may see tidy at dispatch, yet poor gauge control or weak seal quality can lead to splits in transit, particularly when cartons are stacked hard or handled quickly across a busy sortation floor. Pallet stability also matters, because flexible packs can shift and scuff if the load is not banded or enclosed properly. Stock control has to retain the material separate from normal polythene suppliers so the gross reel or bag does not stop up on the line. That makes the packaging selection a production and handling decision, not only a labels decision.

packaging manufacturers suppliers carrier bags should be chosen for strength before appearance, because a tidy printed stop means very small if the handles split or the film deforms when loaded. The useful specification is the one that suits the filling method, the weight carried, and the method the bags will travel through packing and dispatch. Gauge, blend and slip level all affect whether the stock stacks cleanly in cartons or becomes a clinging bundle that slows the line. If the material behaves properly in handling tests, it normally saves trouble at the select-face and avoids weak packs reaching the client.

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: