- 24 April 2007 -
Thermoplastics target new markets
OWENS CORNING is launching two new products in its PerforMax® family of chopped strand glass fibre reinforcements for thermoplastics. One is a high heat resistant product designed for computer and electronics applications, while the second is a hydrolysis-resistant grade developed for use with polyphenylene sulphide (PPS) polymers in components in contact with hot water.
The electronics sector is moving towards the use of higher temperature soldering processes, such as used in surface mount technology (SMT), in part driven by the growing use of lead-free solders, explains Owens Corning Senior Engineer, Hiromasa Suzuki.
"While polymers such as LCP [liquid crystal polymer] and PPS are able to cope with high heat, the same has not been the case for the reinforcements used in conjunction with them and for which higher heat increases outgassing," he says.
Outgassing in small electrical and electronic components like SMT connectors and relay housings results in on-mould deposits, spoiling surfaces and blocking mould vents, and leading to poor release and unacceptable part surfaces. Outgassing can also occur during the assembly of moulded components onto circuit boards, causing defective circuits and rejected parts.
PerforMax SP 798 has been developed to withstand the high temperatures associated with the latest lead-free solder processes and to lower reinforcement outgassing in LCP and PPS. The reinforcement is said to offer temperature performance exceeding 400°C while maintaining high fatigue resistance over application lifetime; and up to 40% lower outgassing then used with LCP and PPS, leading to cleaner mould surfaces, less defects and better part aesthetics.
Owens Corning says the product can deliver similar mechanical and high temperature advantages when used with polyethersulfone (PES) and polyether ether ketone (PEEK) polymers and it can also be used in automotive electrical applications, for products including motor insulators, lamp sockets and coil bobbins.
The second PerforMax reinforcement, HR 562, has been developed for use with PPS. Owens Corning says that it enables PPS to replace metals, as well as alternative hydrolysis-resistant speciality thermoplastics, in hot water plumbing and heating applications. Owens Corning claims that the product offers the highest hydrolysis resistance of any glass fibre reinforcement used in conjunction with PPS, and up to 15% better mechanical strength when compared to alternative hydrolysis-resistant chopped strand products. This can lead to improved economics resulting from replacing brass and bronze or higher cost hydrolysis-resistant thermoplastics.
Japanese valve manufacturer Time Engineering Co Ltd has adopted PPS reinforced with HR 562 for its diaphragm solenoid valves for domestic hot water boilers, where it replaces brass and bronze.
While PPS is a widely accepted polymer of choice for plumbing applications in Japan and throughout Asia-Pacific, it is not yet commonly used by the plumbing and heating industry in Europe or the USA, reports Bernard Kaesmacher, Global Product Manager Chopped Strands at Owens Corning.
"However, because PPS modified with PerforMax HR 562 reinforcement can offer a considerable lower cost option to alternate polymers with comparable hydrolysis and fatigue performance, the material is attracting strong interest from the HVAC [heating, ventilation, air conditioning] industry," has says. "This is borne out by Time Engineering’s growing export sales of its valves into both the European and North American markets."
Owens Corning; www.owenscorning.com
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