What is Polypropylene? Introduction & Recycling Solutions

2023-10-26 | Technical Blog | By Janine Cheng |

Polypropylene (PP), as a semi-crystalline thermoplastic, has high hardness, rigidity and tensile strength. Therefore, PP covers a wide range of reusable items, which makes it the second most widely used polymer in the world. Yet, due to the huge consumption of PP plastics, the environment is polluted due to the lack of infrastructure, incorrect dumping techniques, and mismanagement. This article aims to guide you in knowing more about PP plastic and the recycling solutions for its applications.

What is PP plastic used for?

Except for the properties of a thermoplastic, PP also excels at chemical resistance. Due to the lower density, it’s also light-weighted. Moreover, compared to other plastics, PP is relatively cheap. Combining these advantages, PP plastics are widely manufactured into different products by methods including extrusion, injection molding, thermoforming, and blow molding:

  • Films and bags
  • Food packagings
  • Bottles
  • Containers
  • Toys
  • Ropes, non-woven fabrics
  • Automobile components
  • Electrical and Electronics parts
  • Others

Properties PP
Density 0.895~0.92 g/cm3
Melting point 167~177℃
Appearance Less transparent with haze
  • Economic
  • Light-weighted
  • Heat and chemical resistant
  • Impact resistant
  • Non-toxic and odorless
  • Recyclable

Is PP recyclable?

Absolutely, since thermoplastics can be repeatedly heated, reshaped, and cooled without degradation, PP plastics become one of the most readily recyclable polymers. In this article, you will learn more about PP plastics and the suitable solutions to reprocess different PP applications.

PP plastic recycling process

Recycling Solutions for PP Plastics

To deal with a certain amount of production waste and save more costs, we suggest investing in simple yet reliable plastic pelletizing machines to obtain reusable recycled pellets.

Since PP products can come in the form of soft and rigid plastics, we provide different solutions to achieve the highest performance.

  • Repro-Flex

    The Cutter Compactor Plastic Pelletizing Machine excels in reprocessing PE/PP films and bags without the need for pre-crushing. The cutter compactor ensures efficient cutting and consistent feeding to the extruder. Repro-Flex also performs admirably in recycling injection molding waste, provided they are pre-crushed into 1-inch pieces.

  • Cutter compactor plastic recycling machine for PP plastics

  • Repro-One

    The Shredder Integrated Plastic Pelletizing Machine is specially designed for processing challenging materials like PP raffia, woven bags, non-woven fabrics, lumps, and more. While it's perfectly suited for recycling PP hard plastics, its versatile single-shaft shredder also simplifies the processing of PP films.

  • Shredder plastic recycling machine for PP plastics

  • Repro-Direct

    The Hopper Feeding Plastic Pelletizing Machine features a screw-feeding system designed for handling plastic regrinds and flakes. Pre-crushed materials are fed directly into the extruder, where they undergo degassing and filtration processes.

  • PP hard plastic recycling machine


Polypropylene is extensively employed as a chemical barrier and protective element. With its high consumption rate, the demand for recycling PP is on the rise. Using recycled PP are not only environmentally beneficial but also advantageous for your business, as it reduces waste and enables the production of new items using sustainable materials.

POLYSTAR provides several solutions to recycle PP soft packaging and rigid items. To learn more about these products, please check out here.

PP recycled pellets from PP plastic regrinds
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About the Author
Janine Cheng

POLYSTAR Marketing Assistant

Janine creates engaging content for POLYSTAR’s social media presence, including keeping social media channels updated and brand-focused and seeking ways of connecting with plastic producers and recyclers.

You can find Janine on LinkedIn.