The Ultimate Guide to Polypropylene (PP) Polypeth Ekspor Indonesia July 1, 2022
The Ultimate Guide to Polypropylene (PP)

Polypropylene (PP) is a type of polyolefin which is slightly harder vs polyethylene. It is a commodity plastic with low density and high heat resistance. One of its common uses is as biaxially oriented polypropylene (BOPP) to make clear bags.

Polypropylene (PP) is a tough, rigid and crystalline thermoplastic produced from propene (or propylene) monomer. It is a linear hydrocarbon resin and its chemical formula is (C3H6)n. It is the lightest polymers among all commodity plastics, low density, stress-cracking resistant and the list goes on. It is the second-most widely produced volume plastic after polyethylene.

PP Polypropylene has become a material of choice, especially when you are looking for a polymer with superior strength (e.g., vs Polyamide) in engineering applications or simply looking for cost advantage in blow molding bottles (vs. PET).

Therefore, among variety of structures in PP family and its competitive properties with polyethylene can lead to confusion for you to choose which PP grade is suited for your application. In this guide, get answers to all your queries while looking for a suitable PP grade for your application. Get guidance to select the right commercial grade from >13K products available today.

Let’s first review polypropylene properties over other polymers that may make it ideal for your needs.

Polypropylene and Polyethylene – Two Stars of Polyolefins

Both PP and PE are very similar, but they also have characteristics that are unique to each other, which can be maximized depending on how they are made and the applications they are used for. PP is the second most used plastic after polyethylene and they both can be designed to be durable and lightweight. While both the polymers are used in many applications such as bottles and gloves, but PP has a crystal-clear transparency. Also, polypropylene has excellent mechanical properties and high resistance to fatigue, impact, heat and freezing.

Overall, Polyethylene (PE) is tough yet light, with good resistance to impacts and abrasions and Polypropylene is harder and can be used for mechanical and structural applications as well.

How does PP differ from PE?

PE and PP offer a lot of similarities which makes it easy to confuse the two materials. Understanding the inherent benefits of each can help you pick the perfect material.

They both are highly malleable and have relatively similar impact resistance, meaning strength does not have to be a concern when these plastics are in use. Density is another key factor that differentiates PE from PP. Polypropylene’s density is fixed and only varies when it is filled. On the other hand, polyethylene grade selection is highly dependent on density due to different variations (Low, Medium, High). High Density Polyethylene is known for its big strength-to-density ratio, and it can be more rigid versus PP.

How PP Challenges PET?

Polypropylene (PP) has emerged as a strong competitor to Polyethylene terephthalate (PET), for example in blow-molded bottle applications. Compared to PET, for example, PP is:

  • Less expensive
  • Lighter in weight
  • More resistant to the high temperatures of hot filling
  • Less permeable to moisture.

PP bottles can be hot-filled at temperatures up to 100°C vs PET which cannot withstand filling temperatures above 76°C.

In its pure state, PP is less clear than PET. Also, gas barrier properties of PP are not as high as those of PET, and PP also falls below PET in stiffness. PP has about five times the moisture barrier properties of PET but PP is about 30 times more permeable than PET to gasses such as oxygen and carbon dioxide.

On the other hand, production cycles of PP bottles have generally been longer than those of PET bottles. PP also has a narrower range of processing temperatures than PET.

But producers of PP resins and the additives that go into them are making important strides in overcoming these deficits, such as:

  • Clarifiers are added to PP to enable it to match PET’s transparency. Clarified grades of PP have a clarity and gloss comparable to PET.

  • Nucleators can speed up crystal formation in PP during cooling, thereby shortening cycle times, and sometimes also improving clarity as well. Explore several nucleated PP grades here »

  • Barrier layers (EVOH sandwich, coatings, etc.) enable PP to compete on a cost basis with both glass and PET containers in many food and beverage applications while offering good barrier properties.

Although the need for additives, extra processing steps or added barrier layers to make PP competitive with PET can narrow that cost advantage considerably. But PP still comes out as the more economical packaging choice than PET for many applications.

Our recycled Polypropylene (PP) granules are 100% made from post consumer and industrial waste material. It’s packed in a 25kg durable brown paper sack with monthly capacity up to 30mt. Kindly contact us to find out more about our recycled Polypropylene granules.

Polypeth Ekspor Indonesia is a supplier and export recycled plastic pellets (HIPS & PP) from Indonesia. We work with plastic recycling manufacturers with years of experience to provide and ensure high quality & the safety of our recycled plastic pellets. Together we reduce the use of virgin plastic resin and reduce the waste of virgin plastic pollution.
To find out more about Polypeth Ekspor Indonesia’s products and services, speak to the team by clicking here.

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