Custom extruded polypropylene profiles, parts and products
At HPE Extrusion Solutions, we custom extrude polypropylene and most other common thermoplastic resins, such as polyethylene (HDPE, LDPE), flexible and rigid pvc. Our specialty, however, is the extrusion of innovative engineering resins, such as abs/pvc alloys and difficult to run elastomers, such as Santoprene, nylon and glass-filled abs. We can also combine different resins according to your needs.
Polypropylene (PP), also known as polypropene, is a thermoplastic polymer used in a wide variety of industrial and consumer product applications. Polypropylene is a highly versatile polymer; applications can be found in virtually all plastics end-use markets.
Extrusion is the single most popular process for forming polypropylene, accounting for about 45% of consumption in the US. Approximately two-thirds of all polypropylene extrusions are for fiber and filament products, including carpet yarns, upholstery fabrics, heavy duty webbing, industrial fabrics, textiles, disposable fabrics, woven sacks, twine, rope, cod and strapping. Another major market is film, which is widely used in packaging, particularly for foodstuffs.
At HPE Extrusion Solutions, however, we specialize in extruded polypropylene profiles, parts and products. Typical reasons for choosing polypropylene are: cost, chemical resistance, electrical insulating properties, translucence and “live hinge” applications.
Chemical resistance. Polypropylene is unaffected by dilute and concentrated mineral acids and bases, inorganic salts, solvents and higher molecular weight aliphatics. Chlorinated hydrocarbons will cause it to swell and soften. Polypropylene is, however, attacked by halogens and other strong oxidizing agents.
Translucence In its natural state, polypropylene is translucent, but can be extruded into an unlimited number of colors.
Excellent electrical resistance at higher temperatures
Fatigue resistance. Polypropylene properties include good fatigue resistance (which makes it ideal for living hinge applications) and toughness.
Polyethylene Comparison. While the properties of PP are similar to those of polyethylene, there are other differences as well: polypropylene has excellent electrical resistance at higher temperatures, lower density, higher rigidity and hardness.
Good dimensional stability at high temperature and humidity conditions
Customizeable molecular properties. The large number of end-use applications for polypropylene are often possible because of the ability to tailor grades with specific molecular properties during the manufacturing process.
Customizeable additives. Another characteristics of polypropylene that makes it an attractive choice for many applications is its ability to accept additives. For example, antistatic additives can be added to help polypropylene surfaces resist dust and dirt.
Readily machined. Many physical finishing techniques can also be used on polypropylene, such as machining.
Surface treatments can be applied to polypropylene parts; for example, to promote the adhesion of printing ink and paints.
Dielectrics. Very thin sheets of polypropylene are used as a dielectric within certain high-performance pulse and low-loss RF capacitors.
Available in many grades including: glass and /or mineral filled resins; homopolymer and random copolymer versions; flame retardant grades and specialty grades.
Many objects are made with polypropylene precisely because of its resistance to heat, chemical attack, solvents and glues
“Live hinge” applications Because of its resistance to fatigue, most plastic living hinges, such as those on flip-top disposable bottles and other containers, utilize polypropylene. However, it is important to ensure that chain molecules are oriented across the hinge to maximize strength.
Medical and laboratory instruments Many plastic items for medical or laboratory use are made from polypropylene because it can withstand the heat in an autoclave. Polypropylene plastic typically has a melting point of 320°F (160°C).
Food and beverage containers. The heat resistance, chemical resistance and translucence properties of polypropylene are key factors in selecting this resin for consumer-grade food and beverage containers. Because of its high melting point (320°F, 160°C), polypropylene is often the resin of choice for food storage containers; the hot water used in dishwashers will not cause polypropylene dishware to warp.
The high melting point of polypropylene compares favorably with polyethylene, another popular plastic for containers, which has a softening point at around 212°F, 100°C.
Other types of consumer products. Polypropylene can also be made into disposable bottles to contain liquids, powders or similar consumer products (although HDPE and polyethylene terephthalate are also commonly used). Plastic pails, housewares (such as coffee pots), furniture, appliances (such as washing machine parts), luggage, toys, battery cases, automotive components (bumpers, cladding, exterior trim, batteries), loudspeakers, wastebaskets, pharmacy prescription bottles, cooler containers, dishes and pitchers are often made of polypropylene or HDPE, both of which commonly have rather similar appearance, feel, and properties at ambient temperature.