Laser transmission welding (also called laser welding) is a method of joining plastic parts. It can save costs and produce very small components with complex geometries in a resource-friendly manner. This makes laser welding drive miniaturization of electrical and electronic functions. Therefore, LANXESS has developed a series of laser-weldable polyamides and PBT Durethan LT and Pocan LT (laser transparent), and recently expanded its scope to include three new compounds. At the International Plastics and Rubber Trade Fair K 2019 in Dusseldorf from October 16 to 23, the high-performance materials business unit will showcase these innovative compounds. "In addition to good, process-safe laser weldability, these three new materials have a series of other important characteristics that make them useful in a wider range of applications," said Dr. Claudia Dähling, a specialist in technical plastics. The materials may be used to include parts for electric vehicle drives and driver assistance systems, as well as digital devices that build our Internet of Things.
High hydrolytic stability, but still has good weldability
Pocan B3233XHRLT (currently Pocan TP155-002) is a new 30% glass fiber reinforced PBT compound that has good laser transparency and excellent resistance in high temperature and humid environments. Such materials are almost unprecedented in the market, because ordinary hydrolytic stabilizers usually cause the laser transparency of PBT to be greatly reduced. The SAE / USCAR-2 Rev.6 long-term test by the American Society of Automotive Engineers (SAE) has proven that the latest generation of Pocan HR test products have excellent hydrolysis resistance. "This test is recognized worldwide as the most rigorous test in terms of hydrolysis resistance. In a series of very strict laboratory tests, our products have reached USCAR level 4 to 5 (the two highest levels). Dähling said.
Flame retardant and laser transparent
Most flame retardants also reduce the laser transparency of thermoplastics, which is why PBT, polyamide 6 and polyamide 66 compounds with good laser weldability and high flame retardant properties are rarely seen on the market. However, they are required by the components in the battery system of electric vehicles. Dähling: "We use Durethan BKV30FN04LT to provide the corresponding polyamide 6 compound. With its halogen-free flame retardant packaging, it can pass the UL 94 flammability test of Underwriters Laboratories Inc. in the United States, and the thinnest sample passes the highest V-0 rating Certification. The product can be safely produced in a stable processing window and leaves almost no deposits in the tool. It has a high tracking resistance of 600 V (CTI A, comparative tracking index, IEC 60112), which is very suitable Components for high-voltage batteries and plugs.
Materials tailored for thicker materials
The third new material used by LANXESS for laser welding is Pocan TP150-002. The 30% glass fiber-reinforced PBT compound is optimized for extremely high laser transparency. It has a 13% transmittance, which is about twice the transparency of most other laser-transparent PBT product types (measured using LPKF TMG-3 at 980 nm and a sample thickness of 2 mm). Dähling said: "For design reasons, we have tailored low-cost laser welding materials for parts that require high wall thickness."
HiAnt-supports every detail of laser welding
HiAnt is LANXESS 'customer support service and is also used for the development of laser welding components. Services include the use of CAE tools for component material design. Dähling said: "We can simulate calculations to reduce deformation during production, thereby making the connection process safer and more stable." The service also includes various component tests performed according to customer standards, as well as dynamic tests on larger components It can also be combined with climate testing as required. The service also includes injection molding, welding, sampling and technical support at the beginning of mass production.