Uses for Polypropylene
Polypropylene is a versatile plastic material that is widely used in various industries due to its high melting point and chemical resistance. Its most common application is in food packaging, where it is used to produce microwave and food safe products such as yogurt containers, medicine bottles, and microwave safe trays. Its barrier properties to moisture make it ideal for long-term storage of food and medicine. Other industries that use polypropylene include the automotive, pharmaceutical, and medical fields. In the automotive industry, it is used for battery casings, bumpers, cup holders, and other trim and interior details. In the pharmaceutical and medical fields, it is used for medical devices and supplies such as pill bottles, medical vials, and syringes. Other end uses include chemical bottles, petri dishes, and testing trays. Overall, polypropylene plastic is a reliable and durable material that is suitable for a wide range of applications.
- Commonly used in food packaging: yogurt containers, medicine bottles, microwave trays
- Industries that use PP: automotive, pharmaceutical, medical, chemical
- Automotive uses: battery casings, bumpers, cup holders, interior trim
- Pharmaceutical/medical uses: medical devices and supplies (pill bottles, vials, syringes)
- Other uses: chemical bottles, petri dishes, testing trays
- PP is reliable and durable material suitable for a range of applications.
Here are a few advantages and disadvantages of Polypropylene.
Advantages of Polypropylene
Polypropylene material is known for its high yield, making it an ideal material to be used in the food and medical industry that has high competition and strong price sensitivity. Another reason PP is well suited and mainly used for the food industry is because of the strength of this material after forming, making it resilient to cracking. The low cost and flexibility of this material has made it competitive in replacing standard packaging paper, cellophane and cardboard. It can take up less space, offer protection for products and components, and reduce the amount of waste in the packaging lifecycle. This material can also provide a solution to the unique challenges faced with the large costs of transportation, reducing the weight and therefore pricing down shipping costs compared to typical packaging methods of foam and/or inserts. When in its fiber form, polypropylene can also be used to form ropes, tote bags, twine, string, carpets and even clothing, making it a versatile material used by many industries.
- Polypropylene (PP) ideal for food and medical industries
- PP known for high yield, strength after forming, and low cost/flexibility
- Replaces standard packaging (paper, cellophane, cardboard)
- Saves space, protects products, reduces waste, and cuts transportation costs
- Versatile material in fiber form: ropes, bags, twine, string, carpets, clothing
Disadvantages of Polypropylene
Polypropylene has a few disadvantages, making it a material best suited for particular applications and would be avoided in other applications. One of the disadvantages of PP would be the possibility of UV degradation. This takes Polypropylene out of the competition for applications using high altitude or used in places that have high or prolonged UV exposure. Another downfall of Polypropylene would be its sensitivity to extremely high heat. When exposed to extreme amounts of heat, this material will begin oxidizing and may crack. Along with sensitivity to high heat, it also has a very low melting point compared to other materials, which is what makes it soft and resilient or easily formed when heated. While this is an advantage for having flexible material, it may create an issue because of the lower threshold for flammability, this is because Polypropylene’s melting point is only around 160-170 Degrees Celsius. Compared to materials like PET and HDPE, it has a much lower melting point so it may not be suited for applications that involve high or prolonged heat.
- Polypropylene (PP) best suited for certain applications
- UV degradation and not suitable for high altitude or high UV exposure
- Sensitivity to high heat leading to oxidizing and cracking
- Low melting point (160-170°C) making it flammable
- Soft and flexible but may not be suitable for high or prolonged heat.
Types/Variations of Polypropylene
There are a number of varieties of Polypropylene plastic that you can utilize for specific industries. The food industry can use a food grade form of PP material, as well as the Medical industry can choose to use a medical grade version of PP. There also is recycled polypropylene options available, which can appeal to packages that may not have sensitive materials inside of them. Providing different variations of PP material gives customers options on material properties and prices and can better fit their needs versus just offering a stock material.
Manufacturing process of Polypropylene
The manufacturing process starts with the melting down of resin, or base form polypropylene. Once the resin has been melted and becomes pliable, it can begin to be pushed through an extruding machine. This will begin to flatten and shape the melted resin while it starts to stretch the material. It then continues to get stretched until it meets the desired thickness and material composition. From there the film material sheets will be cooled and wrapped into rolls, which is then taken to the thermoforming machine and run into it in sheets of predetermined lengths that fits the jobs needs. From there, the machines will apply heat and pressure into the mold to form the trays, clamshells and tubs you see all over your local grocery and retail stores.
Recyclability of Polypropylene
Polypropylene can be recycled efficiently if done and understood properly. It can be utilized to create new products like containers, bags, fibers and clothing, textiles and much more. Many people do not think of food packaging being recyclable and reusable, so much of this plastic is wasted. PP has a less common recycling demand and interest than materials like PET and HDPE do, but it is still widely accepted and can help combat some of the waste related to packaging.
Universal Protective Packaging, Inc. (UPPI) places the highest priority on our relationship with the environment and our responsibility to the environment. UPPI’s ultimate sustainability goal is to make sure everything we do has the softest impact possible on the environment. Learn more about UPPI’s Sustainability Mission.
When considering material options for your package, it is important to highlight the aspects you would like to see in that package. With a variety of advantages, Polypropylene has become a staple thermoforming material especially when it comes to food packaging. Because of its properties like high yield, softness and resilience, this becomes the standout package material for food items. Having this material be microwave safe is also a big advantage over alternative food packaging that must be taken out of the package to eat. Because it is also readily recycled, many companies can use this material without adding waste and hurting their “green” initiatives that are aimed at reducing the company’s carbon footprint.