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Tag Archive for: plastics

What’s the difference between UPVC and PVC?

UPVC (Unplasticized Polyvinyl Chloride, PVCu) is a rigid material that can be used for thermoplastic extrusion and is supplied complexly clear or in a variety of colours and strengths. Unplasticised PVC is one of the stiffest polymers at ambient temperatures and is very durable. It is extremely versatile and can be used for UPVC profiles for internal and external applications, such as window frames, fence posts, trims, pipes, cores, cladding, and trunking.

 

PVC (Polyvinyl Chloride) has plasticizers added to make the product more flexible. Flexible PVC is a thermoplastic extrusion polymer used in a wide variety of plastic profiles. It can be very lightweight and is available in various softnesses, grades and a wide range of colours. It is very resilient and is compatible with many additives for colour, UV stabilization, and flame retardants. It is used for sleeves, gaskets trims and hosing, seals, handrails, decking products, wire, and cable insulation to name but a few.

Why recycle plastics?

Plastic products are a valuable resource and not waste. They should be collected, recycled and reused. Products can be rechipped, melted down and reprocessed into a practical material compound that can be used to make the same or other plastic products.

For example, milk, household detergent bottles, shampoo bottles can be made into new bottles, large and small containers, plastic planks, plastic furniture, playground equipment, recycling bins, T-shirts, fleece clothing, insulation for jackets and sleeping bags, carpeting and more. Plastic bottle caps can be recycled and used to make storage containers, reusable shopping bags, rope, garden tools, car batteries, and more bottle lids.

Plastics have a very good environmental profile:

  • Less energy is used to produce it compared to other materials
  • Only a very small percentage of the world’s oil production is used for the production of plastics
  • Plastic products are durable and when they have completed their practical life cycle, they can either be recycled or incinerated to provide a source of energy
  • By being lightweight plastics help to reduce fuel consumption in vehicles, whether in the transport of goods or the manufacture of cars, planes, trains.
  • Plastic packaging reduces food waste and saves energy in transport, and is recyclable
  • Plastic piping reduces leakages and therefore conserves water and saves energy processing and pumping water.

Plastic products have a huge role in sustainable construction providing excellent insulation properties and are cost-effective and provide durability. Replacing natural products with plastic products saves natural resources, e.g., helps to reduce deforestation.

Recycling plastics helps to:

  • Minimise the amount of plastics sent to landfill sites
  • Reduces the environmental impact of plastic-rich products
  • Helps to conserve oil stocks
  • Save energy as it uses less energy than producing new polymers
  • Reduces the impact of plastic waste on the environment.

Why is plastic useful

So why is plastic useful? Thermoplastics, in particular, are lightweight, easy to process, cost-effective, plentiful, resilient, durable, resistant to corrosion and moisture, low maintenance, hygienic, and recyclable. It is because of these benefits that their importance has increased since they were first developed over a hundred years ago. Plastics are replacing the more traditional materials like wood, metal, concrete, rubber, and ceramics as a cost-effective, durable alternative.

Plastic is used for many different products – construction, automotive, aeronautical, rail, medical, safety, military, marine, printing, refrigeration, packaging, electrical and electronics, textile, sports and leisure, and many others. It can be and easily moulded into complex shapes and massed produced to fine tolerances, which makes it easier for engineers to design objects made of plastic rather than in metals or ceramics, for example.

One of the reasons why plastic can be used almost everywhere is that it is not just one material, but a group of materials which contains many sub-categories. There are many different types of plastics polymers, and a lot of them, like Polyethylene, Polypropylene, PVC, ABS, Acrylic, etc., have extremely useful and versatile properties which fit in well with our modern-day lifestyles.

A brief history of plastics

How long is a piece of plastic string? ‘That may depend on the length of polymer chain it was made from’.
Plastic is one of mankind’s most useful and life-saving inventions. There are very few products that have contributed to the development of the modern world as much as plastic polymers. From containers for safe drinking water, insulating copper electrical cables in our buildings, phones, household goods, thermal insulation, bearings, sheeting, netting, medical, windows and plumbing just to mention a few. The list of the uses for plastics polymers are diverse and numerous.

The first plastics were invented over 100 years ago. The first plastic made from synthetic compounds was polyoxybenzylmethylenglycolanhydride, unsurprisingly, became commonly known as ‘Bakelite’ after the Belgian-born chemist Leo Baekeland. It is a thermosetting phenol formaldehyde resin. Thermoset resins are used today in Epoxy resins (glues, fibreglass) Polyester Resin Melamine (worktops) & urea formaldehyde (particle board/low-density fibreboard).

Another early plastic is cellulose acetate which is an organic plastic made from cotton or wood pulp first made in 1865. It is still in use today for camera film eyeglasses frames and laminating film and can be mixed with natural fibres to make a fabric.

Virtually all thermo polymers can be recycled:

a) back into the original product, or
b) into a lower specification product.

Manufacturers have difficulty in persuading buyers that some products could be made from reprocessed materials; although there appears to be a growing trend towards using part recycled materials. Some materials, especially engineering plastics, are more suitable for injection moulding rather than used in an extrusion process

In the next blog we will discuss the various use of the main polymers. It is very important that the correct polymer is used for any application. We would strongly advise any designer to ask advice on which type of plastic should be used from the manufacturers of the material or product.