Plastic bags
What is a plastic bag?
There are two answers to this question. The first one is simple - it is a bag made out of plastic. But not only did you know that already, but it only goes a fraction of the way to actually answering the question.
Plastic bags are often referred to as polythene bags, or polybags. These terms, used to mean the same thing, are all perfectly fine, although the term ‘polyethylene’ bag is more accurate. Most plastic bags these days are made from polyethylene, more commonly known as polythene.
Plastic bags come in all shapes and sizes and cover a multitude of uses, from the trusty old carrier bag that helps millions of people take their shopping home to the specialist waste sacks required by hospitals or people dealing with hazardous waste.
Not to mention all of the bags in between!
Packing bags, waste sacks, bubble bags, anti-static bags, minigrip bags, mailing Bags, postal sacks, waste sacks, black sacks, dustbin bags, bin liners, zip seal bags, recycling bags, biodegradable bags, specialist bags, high tensile strength bags and PolyMax extra strong bags - there’s a lot of polythene bags out there!
How are plastic bags made?
Plastic bags are made from polyethylene, with three particular types of polythene - each of varying densities - widely used for manufacturing bags: low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE) and high-density polyethylene (HDPE).
The exact process of making a plastic bag will vary according to the type of plastic bag in question, the density of the polyethylene and the characteristics that the particular bag will require.
However, there are a few common factors used across the manufacturing of each type of bag. Polythene bags are widely created using a method called ‘blown film extrusion’, also known as the ‘tubular film process’.
The ethylene polymer resin used to create the bags comes in the form of pellets. These pellets are placed into a hopper and melted before being extruded to form a thin tube by forcing cool air into the tube, usually vertically from the bottom of the tube.
Once the tube reaches the correct size and the plastic has reached far enough up the cooling tower and cooled properly, it is taken away and flattened.
At this stage the tube can either be split into two halves, with each side used as a flat sheet of film, or the two sides of the tube can be sealed across the width of the film, before being cut and/or perforated to make plastic bags.
Types of plastic bag
If you say ‘plastic bag’ most people think of a standard carrier bag. However, there are many different types of plastic bag. Here are just a few:
Clear plastic bag - standard plastic bag made of clear or opaque polythene
Coloured plastic bag - standard plastic bag made of coloured polythene
Plain plastic bag - standard plastic bag (clear or coloured) containing no markings
Printed plastic bag - plastic bag printed with a name, logo, design etc.
Carrier bags - the classic traditional shopping bag, available with vest, cut, loop, clip close or grip seal handle styles
Gusseted bags - plastic bags with expandable sides (gusset) and a fitted bottom
Self seal bags - simple plastic seal clicks shut and pulls open to use time and time again (also known as grip seal bags or mini grip bags)
Zip lock bags - plastic bags with a zip seal used to open or close the bag
Drawstring bags - plastic bag with a drawstring at the top that fastens to close the bag
Merchandise bags - premium plastic bags printed with a company logo, slogan or design. Ideal for presentation.
Layflat tubing - cut this poly tubing to size and heat seal for your own made-to-measure bags. Perfect for packaging awkwardly shaped or difficult-to-wrap items.
Bags on roll - a roll of bags, wrapped around a central core, each attached to the next by perforation. Easily detaches with a simple tug
Where can I buy plastic bags?
Manufacturers and suppliers of plastic bags include:
Polybags Bulk Sales
Polybags Bulk Sales provides a low cost bespoke manufacturing service for large volume UK polythene users and packaging businesses. Orders placed directly with the manufacturers.
www.polybagsbulksales.co.uk
Polythene-Bags
Polythene-Bags.co.uk specialises in polythene bags with a range that includes mailing bags, waste sacks, display bags and more. With over half a century experience providing polythene packaging we're sure you will find the very best in polythene and polypropylene products.
www.polythene-bags.co.uk
Buy Plastic Bags
A brilliant resource if you want to buy plastic bags, with the ability to order online direct from the supplier. Contains loads of information on the different types of plastic bags available to buy, how plastic bags are made, how to promote your brand with printed plastic bags and much more.
www.buyplasticbags.co.uk
Buy Polythene Bags
BuyPolytheneBags.co.uk offers an extensive guide to polythene bags. With loads of information about all types of plastic packaging, from self-seal bags to antistatic bags to eco-friendly ones. Order direct from the manufacturers at low prices and with free delivery across the UK.
www.buypolythenebags.co.uk
Polybags Ireland
Online retailer of poly bags and polythene packaging offering the Irish the chance to save an extra 21% of all packaging products range.
www.polybags.ie
Polythene Bags
Dedicated division of a major UK packaging supplier and manufacturer, devoted to polythene bags. Working with polythene bags for over 50 years and now offering an increasing range of environmentally friendly products across the packaging spectrum.
www.polythenebags.co
Discount Polybag
International distributor of polythene packaging. Discount Polybag work direct with the manufacturer and can therefore extrude polyethylene film and make polythene bags to suit any order at a price that is right for you.
www.discountpolybag.co.uk
Polythene Bags
Polythene bags and plastic carrier bags specialist providing information about polythene bags, packaging and manufactured bags. All polythene packaging available direct from the manufacturers at low prices that don't compromise the quality.
www.polythenebags.eu
Discount Plastic Bags
Lists discount suppliers of shopping bags, polythene carrier bags and clear plastic bags. Discover how plastic bags are made, the differences between low and high density polythene and what eco-friendly options are available.
www.discountplasticbags.co.uk
Cheap Plastic Bags
Cheap plastic Bags has loads of information on plastic bags with useful links for you to buy quality products at great prices. Find out more about clear plastic bags, heavy duty plastic bags, resealable plastic bags, biodegradable plastic bags and more on this helpful website.
www.cheapplasticbags.co.uk
Research & Resources
For loads more detailed information about plastic bags, from the start of the production process right through to recycling, including details of the different types of plastic bags available, please visit:
Plastic Bags
A free online directory specialising in polythene packaging. Find great websites with lots of information on plastic bags and post your own product listings for free.
www.plasticbags.uk.com
Packaging Knowledge
This online magazine contains in-depth news and information on the world of packaging. Read articles and features and fact sheets about a variety of plastic bags.
www.packagingknowledge.com
Goldstork
Very useful "pick of the web" directory containing lots of interesting, off-beat and unusual websites. Goldstork also offers a vault with only selected hand-picked websites specialising in plastic bags.
www.goldstork.com
Notes on Plastic Bags
A blanket ban on plastic bags can cause more problems than it solves if no practical substitute is prepared for shop floors and checkout counters. Standard polythene suppliers bags are light, cost-effective to store, and easy to occupy fast, which is why they have stayed normal in shopping and distribution. The proper issue is not simply the bag itself, nevertheless how much of it becomes litter or low-value waste after use. A sensible policy sees at thickness, reusability, and disposal routes rather than treating all bag as the same. If a business switches to a better-controlled bag format, the change can work without slowing packing or creating additional handling damage.
Clear LDPE polythene suppliers bags need to be specified for consistency first, because small variations soon display up in sealing, handling and serviceable shelf life. A bag that comes in below gauge may split at the weld or tear on a carton edge, while one that is also stiff can slow down packing and make cool-store or early-shift work more awkward than it should be. Film clarity also matters because pickers, scanners and inspectours need to see contents fast, and a hazy stop can waste time. Good control of melt flow, slip and puncture resistance gives a bag that runs well on the line and behaves predictably in the warehouse.
Why not the trash? Or why can't they only give us another bin for the plastic bags and wrap?
Plastic bags can throw a sorting line into chaos because they behave none like rigid bottles or cans. Lightweight film lifts on air currents, wraps around rollers, and clings to moving parts, so a machine install for clean separation beginnings seeing pollution instead of product flow. Once enough bag film collects, sensours miss items, belts slow, and operatours have to stop the line to transparent jams by hand. That means lower throughput, more wear on the equipment, and a higher risk of mixed recyclables ending up in the gross bale. Keeping loose bags out of the feed stock makes the all process dash cleaner and with less downtime.
6X8″ 250g polythene suppliers Bags
A 250-gauge polythene suppliers bag in a 15 x 20 inch size gives a useful middle option for secondary packing because it has enough strength for boxed parts and awkward shapes without becoming stiff at the packing bench. The film requirements proper gauge control across the web, otherwise thin areas turn into split seams, corner punctures and wasted time when bags fail amid picking or sealing. That balance matters on a busy line, where the bag must open easily, take a decent seal and still transport fast through stock-handling tasks. A well-manufactured bag in this spectrum cuts down on rework and retains the pack area running with less interruptions.
Ban use of plastic bags in United Kingdom by 2020
Plastic bags can hurt land animals long after a shopper has finished with them. A lightweight carrier left in a hedge, field, or verge can cling to fur, wrap round a leg, or be gross for food by grazing animals and wildlife. In handling terms, the problem is not only the bag itself nevertheless the method it escapes the waste stream through poor assortment, littering, or weak stock control at shopping and depots. A bag that seems harmless at the counter becomes a risk once it is loose outdoors. Better recovery and cleaner disposal habits reduce that danger fast.
More Manufacturers and Suppliers of polythene suppliers Bags
polythene suppliers bags remain a practical selection when light weight, moisture resistance, and low packing cost all matter in the same job. For warehouse and shop-floor use, the proper value is not only the bag itself nevertheless how it behaves in handling: it slips easily above products, takes up small storage space, and can be provided in the gauge and size needed for the load. Poorly chosen film, though, can split at the seal, tear amid select-face work, or let dust and damp in. A sensible specification retains packing fast and reduces avoidable handling damage.
Recycling and reusing plastic bags
A 2005 study by the Waste & Resources Action Programme (WRAP), cited by the Environment Agency in their 2011 report ‘Life Cycle Assessment of Supermarket Carrier Bags’, reported on how traditional lightweight ‘single use’ carrier bags were used after their initial intended use.
Their survey found that 89% of respondents reused at least some carrier bags. 59% of people said they reused all carrier bags, while 16% reused most of them, 7% reused around half and 7% reused some. Overall, it was estimated that 76% of carrier bags were reused.
The report also included details of how people reuse their carrier bags. The results can be found in the table below.
The reuse of lightweight carrier bags (WRAP 2005 survey)
| Reuse applications | % of respondents |
| Bin liner in kitchen | 53% |
| Put rubbish into it then throw it away | 43% |
| Bin liner in other rooms | 26% |
| Store things at home | 14% |
| Dog / cat / pet mess | 11% |
| Reuse for other shopping | 10% |
| Reuse for supermarket shopping | 8% |
| Packed lunches | 8% |
| Carry other things in when going out | 4% |
| Garden refuse | 1% |
| Give to charity shops | 1% |
| Put football boots / wellies in | 1% |
| Keep bottles / cans in for recycling | 1% |
| Other uses | 2% |
| Do not have a use / discard | 11% |
Source: Environment Agency - Life Cycle Assessment of Supermarket Carrier Bags
