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
Stay tuned forPlastic bags: What’s the big offer? (pt 2)
Plastic bags are often reused far less than people imagine, and that matters because most of them stop up sitting in cupboards until they are binned anyway. A bag used for a bathroom caddy or to transparent up after a dog only acquires a short second life before it connects normal waste, so the practical earn is small unless there is proper, normal reuse. From a packaging point of view, that makes stockpiling loose carrier bags a poor habit for households and stores alike, because it clutters space and delays proper disposal. A couple of robust reusable bags tend to cover most daily jobs without building up a back-up pile.
polythene suppliers bags should be kept prepared because small packaging jobs can stop cool whenever the proper size or gauge is missing at the point of use. In a warehouse or on a packing line, having bags close to hand avoids wasted movement, slower picking, and awkward last-small substitutions that can lead to split seams or poor product protection. The practical value is simple: a modest stock of the proper bags retains dispatch moving and assists absorb peaks in demand without tying operatours up searching for materials. Good stock placement also assists cleaner handling and tidier secondary packing. A prepared supply prevents minour delays from becoming avoidable dispatch problems.
California will soon be the first state in US to ban plastic bags
Plastic bags are often blamed in big terms, nevertheless the proper issue is how the bag is specified, used, and recovered after use. A thin polythene suppliers bag can be light enough to cut transport weight and store efficiently, yet it also requirements proper handling at the packing stage because poor sealing or the gross gauge leads to split seams and client complaints. In warehouse and shopping work, film slip, bundle size, and pallet stability matter only as much as material selection. A bag that is used once and thrown away is wasteful, nevertheless one that protects product cleanly and folds into a tight stock footprint can reduce damage and handling losses. The practical reply is to match the bag to the job, then make sure assortment and recycling are realistic.
Clear polythene suppliers Bags
Clear polythene suppliers bags need the proper size if they are going to keep safe stock properly and still display it off neatly. A transparent bag lets the contents stay visible on the shelf or in a picking area, which assists with identification and gives a cleaner presentation than plain outer wrapping. The fact that seven sizes are on offer matters on a packing line, because a bag that fits closely reduces excess material, cuts down on fat folds, and makes sealing or closing easier. It also assists retain items clean amid handling and storage, so the contents arrive looking presentable rather than scuffed or dusty. The optimal selection is the size that balances protection, visibility, and tidy packing.
Are plastic bags getting a inferior rap?
Plastic bags still have a place in packaging, nevertheless their use has to be judged against the job they are meant to transport out. In shopping and despatch, they are valued for low weight, superb moisture resistance, and the method they fold flat in storage, which assists with select-face efficiency and retains secondary packing simple. They also tend to handle a mixed load better than a few paper grades when the contents are awkward or slightly greasy. Even so, the proper decision comes down to product protection, client expectation, and waste handling at the stop of use. A plastic bag can be the sensible selection, nevertheless only when its strength and handling match the need.
polythene suppliers bags have to be matched to the job, not only ordered by name, because the gross gauge or film type causes split seams, poor stacking and wasted material. A bag for light loose products behaves very differently from one carrying damp, abrasive or strange contents, and a supplier that works with several film types can select between HM, HDPE, LD and LLDPE to suit strength, flexibility and sealing. That matters in converting as well, because a bag that runs well on the machine will seal cleanly, pack faster and stand up better in storage and transit. Getting the specification proper reduces handling damage and retains finished stock easier to use.
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
