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Polypropylene is considered the steel of plastics due to its versatility; it can be modified in countless ways to suit multiple applications. It has become the second-most widely produced plastic in the world. When it was first made in 1951, its popularity soared within six years, and today is the material of choice for manufacturers in a variety of industries.

Polypropylene is commonly used in the packaging industry, and in this article, we are looking at the advantages and disadvantages of the material.

Bottle caps made from polypropylene

Advantages

Polypropylene has many benefits which have made it such a popular material for manufacturers who can apply it to many uses. See what the main advantages of the material are below.

  • Polypropylene’s chemical properties mean it does not react with acids which makes it the ideal material for containers made to hold acidic liquids such as cleaning agents.
  • Polypropylene is also highly resistant to corrosion and chemical leaking, making it the choice material for piping systems. The plastic resists to freezing well too, so climate conditions are also not an issue for polypropylene pipes.
  • Polypropylene will turn to liquid at its melting point, and in this form, it can be moulded into any desired shape, and this can be done several times without much degradation to the plastic. Polypropylene is used in injection moulding because of how it responds to heat.
  • Polypropylene does not conduct electricity well, and so is classed as an insulator. This has made it an excellent material for manufacturing to be used with electronic components such as cables and audio equipment.
  • Polypropylene is highly impermeable, absorbing less than 0.01% of water when soaked it in. This makes it perfect for products which are submerged in liquids or items which need waterproofing.
  • Polypropylene is malleable, which means it can be made into a living hinge; a piece of material which can bend without breaking even after repetitive bending.
  • Polypropylene has a high tensile strength, which means it is a useful material for heavy loads, as it can withstand 4800 psi.
  • Polypropylene is also low density when compared to other plastics, so for manufacturers, they have the benefit of saving money from low weight.

Plastic chairs in a stadium made of polypropylene

Disadvantages

Like all manufactured materials, polypropylene has some drawbacks which users and manufacturers should be aware of before they apply the plastic material.

  • Polypropylene is often affected by UV degradation, making it not suitable for use in high altitude or places where UV penetration is high.
  • Polypropylene has limited use in high temperatures as it suffers from chain degradation which can lead to oxidisation. This results in cracks appearing in the polypropylene but can be fixed with polymer stabilisers.
  • Polypropylene has poor bonding properties, which makes it a hard material to paint. One solution for this is to treat the surface to enhance the adhesive strength of paints and inks which can colour the polypropylene.
  • Polypropylene is extremely flammable and will melt when exposed to heat. The flash point, the temperature at which a liquid produces flammable vapour to form a mixture which can be ignited when contacted with a spark or flame, is just 260 degrees Celsius.

Get in touch with us at Kempner to find out more about the products we offer such as polyolefin shrink wrap, and take a look at our blog for more information on the shrink wrap materials.