JST Corp., a global manufacturer of interconnection products, has eliminated stress cracks in its injection molded Secure Digital (SD) connector thanks to the superior weld-line strength and higher heat deflection properties found in inherently flame resistant Vectra® liquid crystal polymer (LCP) from Ticona Engineering Polymers.
"With technical assistance from Ticona, JST was able to switch to Vectra S135 and start molding thin-wall parts with excellent process consistency and good surface appearance," said Miguel Padilla, JST Molding Supervisor at JST in Waukegan, Ill. "Now we have the extended operating temperature and flowability that allows us to consistently fill these complex geometries while, at the same time, maintaining tight tolerances and avoiding assembly process issues."
When molding with a 10 percent glass, 30 percent mineral reinforced LCP resin with a distortion temperature under load (DTUL) of 248 degrees Celsius (479 degrees Fahrenheit), JST had been experiencing weld-line issues and occasional cracks that developed during the assembly process. JST needed an engineering thermoplastic with a higher heat deflection temperature (HDT) profile that could withstand the particularly challenging dimensional considerations and withstand lead-free soldering demands of this SC connector application for handhelds such as bar code scanners.
JST turned to Ticona for material and processing technical assistance. During molding trials, Ticona demonstrated that JST could make the successful material switch to Vectra S135 and eliminate intermittent fill and bowing issues its molder was experiencing with SD connector parts molded with the other commercially available LCP.
"Ticona designed Vectra S135 to meet the needs of customers like JST ultra-high heat resistance, thinner walls and faster cycle time," said Edward Hallahan, technical marketing manager Ticona High Performance Polymers. "By switching to Vectra S135, JST also was able to optimize their molding process to reduce cycle times by 4 seconds."
As a member of the high-temperature Vectra S series family, Vectra S135 significantly extends the possible processing window with a melting point of 350 degrees Celsius (662 degrees Fahrenheit). It is a 35 percent glass fiber reinforced LCP with very low outgassing and high stiffness designed for use in demanding connector and surface-mount applications, especially those that must meet Restriction of Hazardous Substances Directive (RoHS). A unique polymer structure allows S135 to achieve a high DTUL, and process stably at temperatures significantly lower than other high-DTUL LCPs. It offers:
* A DTUL of 335 degrees Celsius (635 degrees Fahrenheit)
* Improved weld-line strength
* Reduced viscosity, which allows it to fill walls as thin as 0.2 mm (0.008 in)
Vectra LCP is widely used by customers to make eco-friendly connectors, bobbins, switches and relays that meet RoHS and European Waste Electrical and Electronic Equipment (WEEE) directives. In addition, customers and original equipment manufacturers are striving to accelerate the production of green and safe products.
Ticona Enables Eco-Friendly Innovation
Ticona is a solutions-driven company and is well positioned to help develop eco-friendly innovations. For the ever-increasing demands of the electronics market, Ticona has a broad product line that complies with the RoHS directive, which limits the use of heavy metals and brominated flame retardants such as polybrominated biphenyls (PBB) and polybrominated diphenyl ethers (PBDE). The materials allow original equipment manufacturers to comply with WEEE, which imposes costly separation requirements for recycling, energy recovery or disposal of products containing brominated fire-retardants. The Ticona product line (www.ticona.com/halogenfree) of “Polymers For Eco-Friendly Innovation™” includes:
* Vectra LCP Inherently flame resistant, UL94 V-0, and halogen-free without additives, Vectra LCP is a family of high-performance polymers based on patented Ticona technology. Introduced 22 years ago, the product line has evolved to include innovative grades that keep pace with market needs for thinner walls, higher temperature resistance, higher production rates, lower overall part costs and recyclability.
* Zenite® LCP Inherently flame resistant, UL94 V-0, and halogen-free without additives, Zenite LCP provides solutions for complex thin-wall parts, delivering high-temperature resistance to meet requirements for lead-free soldering, toughness, strength and dimensional stability. (Zenite LCP, and Thermx® polycyclohexylene-dimethylene terephthalate (PCT), was acquired from DuPont Performance Polymers to build on the Ticona portfolio of environmentally friendly electrical and electronic product solutions.)
* Celanex® XFR PBT UL V-0 and RoHS compliant with a proprietary flame-retardant system, the enhanced Celanex XFR PBTs will allow customers to use them as a virtual “drop in” replacement for most similarly available PBTs without having to modify designs, build new molds or make significant tooling changes.
* Riteflex® XFR thermoplastic polyester elastomer (TPC-ET) The only TPC-ETs on the market that have a V-0 flammability rating at 1.5mm thickness for all colors, the new grades Riteflex XFR 440 (Shore D Hardness of 40) and Riteflex XFR 440 (Shore D Hardness of 55) help customers comply with hazardous substance restrictions and waste directives.
* Fortron® polyphenylene sulfide (PPS) Satisfying the UL94 V-0 flammability rating without the addition of flame retardants, Fortron PPS is ideal for use in applications where exacting electrical properties are required, making it a material of choice for making connectors, switches and other applications such as jigs used in semiconductor production and testing.
About JST Mfg. Co., Ltd.
JST Mfg. Co., Ltd. was established in 1957. Since then, a reputation for innovation and excellence has kept JST as one of the top ten connector manufacturers in the world with annual sales of approximately $100.0 billion. JST Group has a global network of production sites, R&D facilities, and service centers. It’s business philosophy is to provide customers with the most reliable, technologically advanced and cost-efficient products. The JST website is www.jst-mfg.com.
About Ticona and Celanese
Ticona, the engineering polymers business of Celanese Corporation, produces and markets a broad range of high performance products, and posted net sales of $808 million in fiscal 2009. Ticona employs more than 1,450 individuals at production, compounding and research facilities in the USA, Germany, Brazil and China. For more information, please visit www.ticona.com or www.ticona.cn (Chinese language).
Celanese Corporation is a global technology leader in the production of specialty materials and chemical products which are used in most major industries and consumer applications. Our products, essential to everyday living, are manufactured in North America, Europe and Asia. Known for operational excellence, sustainability and premier safety performance, Celanese delivers value to customers around the globe with best-in-class technologies. Based in Dallas, Texas, the company employs approximately 7,400 employees worldwide and had 2009 net sales of $5.1 billion, with approximately 73% generated outside of North America. For more information about Celanese Corporation and its global product offerings, visit www.celanese.com.
Vectra®, Zenite®, Celanex®, and Riteflex® are registered trademarks owned by Ticona or its affiliates.
Fortron® is a registered trademark of Fortron Industries LLC.
Stress Cracks Eliminated JST Corp. is no longer dealing with periodic stress cracks in their injection molded Secure Digital (SD) connectors thanks to the superior weld-line strength and higher heat deflection properties found in inherently flame resistant Vectra® liquid crystal polymer (LCP) from Ticona Engineering Polymers.