Polypropylene applications automotive

The advantages offered by the use of expanded polypropylene in automotive bumper cores and other applications are considered, and its properties are compared with other materials traditionally used in such applications in terms of impact strength, energy absorption, resilience, and compressive strength. 

The introduction of HALS led to a large increase of the UV stability of polymeric materials. Without the discovery of HALS, the outdoor applicability of many polymers would be limited. So would the use of polypropylene in automotive application without the use of HALS be impossible. 

Van Poucke J, James A. Long glass fiber polypropylene technology for automotive applications. Automotive Composites Conference, conference proceedings. Society of Plastics Engineers 2006. 

These trends are illustrated by DuPont Dow Elastomers range of Engage polyolefin elastomers, intended as impact modifiers for polypropylene in automotive bumpers and fascias. They combine stiffness with ductility, and are claimed to give very good low temperature impact strength. Engage 8842 is said to have a particularly wide range of applications. 

Polypropylene + ethylene/propylene/diene rubber, PP + EPDM. Applications automotive parts, flexible tubes, sports goods, toys. 

PRINCIPAL BLEND APPLICATIONS Automotive, particularly dashboards and glove boxes CRITICAL FACTORS AFFECTING PRODUCT PERFORMANCE Mold similar to conditions used for mineral-filled polypropylene FINISHED PRODUCT PERFORMANCE Provides very high impact resistance in crash tests. 

J. Gosden, Proceedings of Polypropylene in Automotive Applications, Rapra Technology Limited, Shawbury, UK, 1992, Paper 15. 

The use of ABS has in recent years met considerable competition on two fronts, particularly in automotive applications. For lower cost applications, where demands of finish and heat resistance are not too severe, blends of polypropylene and ethylene-propylene rubbers have found application (see Chapters 11 and 31). On the other hand, where enhanced heat resistance and surface hardness are required in conjunction with excellent impact properties, polycarbonate-ABS alloys (see Section 20.8) have found many applications. These materials have also replaced ABS in a number of electrical fittings and housings for business and domestic applications. Where improved heat distortion temperature and good electrical insulation properties (including tracking resistance) are important, then ABS may be replaced by poly(butylene terephthalate). 

TPO applications are in automotive bumpers and dashboards because of their higher toughness than conventional polypropylene copolymers. 

Borealis has developed a high-performance short glass fibre reinforced polypropylene (HPGF) family that has the technological and economical potential to replace long glass fibre (LFRT) in highly stressed parts for technical automotive applications. 

When the polypropylene (PP) technology finally ripened in the late 1950s, the chemicaL.industry was quick to harvest numerous applications. The primary attractions of this thermoplastic were the ease of molding or extruding it and its ability to hold color. Some of the familiar applications are automotive parts, luggage, pipe, bottles, fiber (particularly carpet face fiber and rope), housewares, and toys. 

Brookfield, Ct., SPE, 2002, Interior Applications Session, p.97-117, 27cm, 012 SIMPLIFIED HIGH EFFICIENCY POLYPROPYLENE FOAM PART DESIGNS FOR AUTOMOTIVE HEADLINER COUNTERMEASURE APPLICATIONS... 

The article describes the process of producing expanded polypropylene foam parts with a solid integral skin on one side, citing a bicycle helmet moulded from BASF s Neopolen EPP bead, as an illustration. The self-skinning EPP process reqnires some modification of standard beadmoulding equipment, needing an extra steam chamber. Automotive interior trim is a potential application for the process. 

Chemical reactions enhanced by catalysts or enzymes are an integral part of the manufacturing processes for the majority of chemical products. The total market for catalysts and enzymes amounts to 11.5 billion (2005), of which catalysts account for about 80%. It consists of four main applications environment (e.g., automotive catalysts), 31% polymers (e.g., polyethylene and polypropylene), 24% petroleum processing (e.g., cracking and reforming), 23% and chemicals, 22%. Within the latter, particularly the catalysts and enzymes for chiral synthesis are noteworthy. Within catalysts, BINAPs [i.e., derivatives of 2,2 -bis(diphenylphosphino) -1, l -bis-l,l -binaphthyl) have made a great foray into chiral synthesis. Within enzymes, apart from bread-and-butter products, like lipases, nitrilases, acylases, lactamases, and esterases, there are products tailored for specific processes. These specialty enzymes improve the volumetric productivity 100-fold and more. Fine-chemical companies, which have an important captive use of enzymes, are offering them to third parties. Two examples are described here ... 

Compounds based on S—EB—S usually contain polypropylene, which improves solvent resistance and processibility and raises upper service temperatures. Compounds intended for use in the automotive industry are able to survive 1000 hours air exposure at temperatures of 125°C with only minor changes in properties (54). Very soft compounds have been developed to replace foam mbber for interior trim parts. In this and similar applications, these soft compounds are usually insert molded over polypropylene or metal and then coated with flexible polyurethane paint (55). Other automotive applications include products intended for sound deadening, flexible air ducts, and gear shifter boots, as well as improving the properties of sheet molding compounds. 

Polypropylene (PP) resembles PE, but is somewhat harder and stiffer than HDPE. It is crystalline as well, and melts at 165 °C. Its impact strength at lower temperatures is quite poor therefore PP is often modified with a certain amount of rubber (mostly built-in as a copolymer). Main applications are film for packaging, fibres, crates, pipes, automotive parts (often with reinforcing fillers). A special feature of PP is its ability to form integral hinges with a practically unlimited resistance against repeated bending. 

As a result of its saturated polymer backbone, EPDM is more resistant to oxygen, ozone, UV and heat than the low-cost commodity polydiene rubbers, such as natural rubber (NR), polybutadiene rubber (BR) and styrene-butadiene rubber (SBR). Therefore, the main use of EPD(M) is in outdoor applications, such as automotive sealing systems, window seals and roof sheeting, and in under-the-hood applications, such as coolant hoses. The main drawback of EPDM is its poor resistance to swelling in apolar fluids such as oil, making it inferior to high-performance elastomers, such as fluoro, acrylate and silicone elastomers in that respect. Over the last decade thermoplastic vulcanisates, produced via dynamic vulcanisation of blends of polypropylene (PP) and EPDM, have been commercialised, combining thermoplastic processability with rubber elasticity [8, 9]. 

---