Second only to polyethylene in volume alone, polypropylene (PP) is one of the most common plastics used worldwide. Despite its ubiquity, however, it’s still vital for engineers and entrepreneurs alike to comprehend polypropylene plastic, including its structure and properties. Its uses are vast, as it is a part of everything from living hinges and bottle tops to textiles and various packing applications. In addition to being found in full-production manufacturing, polypropylene plastic is a material that Creative Mechanisms is well-suited for prototyping with.
PP is a synthetic resin built up by the polymerization of the organic compound propylene. Polypropylene plastic’s structure and chemical makeup showcase the following properties:
Polypropylene plastic’s material properties and chemical structure render it extremely useful for a broad range of applications. Thanks to suitable viscosity, it’s relatively easy to injection mold. It’s also highly resistant to most other materials (such as acids or bases), so it’s ideal for both consumer and industrial uses. It exhibits high levels of strength, even in very thin gauge applications such as bottle tops or living hinges.
As a thermoplastic material (as opposed to thermoset), it’s proved to be extremely cost-effective due to the ability of excess material to be reheated and recycled for continued use. PP does not present stress-cracking issues and offers formidable electrical and chemical resistance at high temperatures.
While polypropylene plastic’s inherent properties are similar to those of polyethylene, there are several differentiating factors. These include a lower density in PP, as well as a higher softening point (PP does not melt below 160° C, while polyethylene will anneal at around 100°C) and higher rigidity and hardness. Additives are applied to commercially produced PP resins to improve their manufacturing process and ensure optimal end-us
As an FDA-approved food contact material, PP is widely regarded as being the safest of all plastics. Due to its high heat tolerance, PP is unlikely to leach, even when exposed to warm or hot water.
PP is most often used for single-serve containers such as yogurt cups but is also present in reusable containers that many use to store leftovers. It’s microwave safe and nonvolatile, which means it won’t react with any food you store in it, regardless if it is acidic, basic, or liquid.
PP is the most beneficial material when it comes to manufacturing living hinges, due in large part to their flexibility and softness. Manufacturing these hinges with another type of material makes it difficult for the hinge to rotate on its axis, which is why we trust this product when prototyping living hinges.
The team at Creative Mechanisms helps put your company’s vision into motion by implementing cutting-edge technology and utilizing polypropylene plastic’s structure and properties to manufacture products that push your business forward. To learn more about how we help all of our clients, follow the links below: