Related: Automotive Materials
Making the Switch
The reliability of driver’s side door switches for minivans—the activation of which cause the sliding doors to operate—is said to be improved through the use of an internally lubricated glass-filled nylon 6/6 alloy. The material, Lubriloy from LNP Engineering Plastics (Exton, PA), is being used for recently designed switches that are mounted on the minivan’s B-pillar.
Among the cited benefits:
- The switch’s polycarbonate button won’t stick to the injected molded switch base. (Apparently, the material that had been used for the switch bases, glass filled nylon 6/6 [note: not an alloy like the material in question], tended to have its surface layer resin worn away by the polycarbonate button such that the button would stick on the glass reinforcement below.)
- The cold-weather embrittlement problem (e.g., the previous switch base tended to embrittle and fail when snapped into a B-pillar during cold weather) is eliminated due to better elongation properties of the alloy.
- Warp potential is minimized through improved dimensional stability and moisture resistance.
Approximately 400,000 of these components are molded annually.
Obviously, under the hood is a nasty place to be...for wires, cables and hoses. There are heat, vibrations, dirt, oil, and moisture to contend with. So, to facilitate longer life for these components, Federal-Mogul System Protection Group (Exton, PA) has developed a new valve and cable sleeving that’s resistant to cut-through and abrasion. It’s body and loop are made with polyester (PET) material; the hook portion is made with nylon monofilaments. Speaking of FlexWrap 2310, Phil Marks, the company’s Automotive Applications engineer, notes, “This combination of properties is critical for bundling wire harnesses and other sleeving applications where both space constraints and aesthetics are important issues. And, because the hook is integrally woven, we’ve eliminated the possibility of sew-line failure.”
Toyota Motor Corp. has a strong commitment to providing more environmentally correct vehicles. As such, the vehicle manufacturer’s engineers are looking at a variety of applications, all the way to the trim seals for its doors.
It has recently commercialized a recy-clable thermoplastic vulcanizate (TPV) rear-door opening trim seal for the bB model sport utility vehicle that it sells in the Japanese market. The seal is a co-extrusion of TPV and metal. It weighs approximately 800 g, which is 30% lighter than a traditional seal made with PVC. Additionally, the seal is said to be easier to install and has a good appearance. The TPV material is Santoprene, from Advanced Elastomer Systems (Akron, OH).
The TPV is recyclable in the olefinic recycle stream.
To learn more about the material, write in 142 on the Reader Service Card.
A rust preventative that provide protection for metals for up to a year? One that’s biodegradable? That’s what the people at Cortec Corp. (White Bear Lake, MN) say they’ve developed. With methyl esters—from soybeans.
The EcoLine rust preventative can be sprayed, dipped, or brushed onto parts and components. Workers are said not to need to wear special safety equipment when using it. The material is said to be highly resistant to humidity.
Looking for a way to minimize the use of solvents in adhesive assembly applications?
Loctite Corp. (Rocky Hill, CT) has recently introduced a line of water-based adhe- sives for automotive applications. Accord-ing to the company, these adhesives can be used on both porous (foams, cloth, felt, insulation) and nonporous (metal, plastic, wood) materials. They are said to be available with fast-tack and foam tearing strength comparable to solvent-based adhesives. They can be applied with spray guns or coating machines.
An alternative to producing long fiber thermoplastic (LFT) composites with molding pellets or glass mat thermoplastic (GMT) materials is being touted by Composite Products, Inc. (CPI; Winona, MN) as being more cost-effective in providing high-temperature stiffness for components. According to the company, adding 40% glass reinforcement to polypropylene homopolymer raises the heat distortion by 50%; adding the same amount of glass reinforcement to nylon 6 raises its heat distortion temperature by 16%.
But in order to achieve that, the company claims, the molder has a choice: using prefabricated glass/resin pellets or using CPI’s patented direct feed thermoplastic (DFT) process. The direct approach, skipping the pellet manufacturing, is said to save the molder about 40% (e.g., for a 40% glass-reinforced polypropylene, the pellet material cost is said to be $1.40/lb. versus $1.00/lb. for the DFT material).
Briefly, the DFT process employs a proprietary extruder design that gently mixes the fiber/resin melt such that the reinforcing fibers aren’t damaged so that they maintain a high degree of their initial length in the compounded thermoplastic composite.
One cited application of a 40% glass-filled polypropylene that’s made with the DFT process is an under hood front end assembly that is used by Volvo to replace a metal part (the high resistance to heat distortion is said to be a reason why the composite can be used in this application).