Continental Structural Plastics Reveals Solution to Improve Assembly, Serviceability of EV Battery Enclosures

Auburn Hills, Michigan – February 1, 2021 —Continental Structural Plastics (CSP), along with its parent company Teijin, has introduced a patent-pending clip system that repl aces the need for bolts in the process of joining the top and bottom of an electric vehicle battery case. This clip system improves the seal, reduces assembly costs, and makes the batteries easier to service when needed. The clips will be manufactured at CSP Stamping in Manchester, Michigan.

These steel clips affix to the company’s multi-material battery enclosure via molded-in features instead of using secondary machined holes and welds to join the top and bottom sections of the box.  Unlike a point load created by using a bolt, these clips spread the seal load more evenly across the upper and lower flange. On CSP’s multi-material battery enclosure, 68 clips designed to hold 3 PSI of internal pressure replace 72 bolts that would all need to be torqued to a specified value. Each clip provides 950 Newtons of clamp force.

By eliminating the need for bolts or bonding of any sort, a box assembled with these clips is easier to assemble and is much easy to service if the internal cells need repair or replacement.

“By using these clips in place of multiple fasteners and different types of welds, we can reduce assembly cost, complexity and the amount of scrap involved in the production of each enclosure,” said Hugh Foran, executive director of CSP’s Advanced Technologies Center. “Our customers come to us with a number of challenges when it comes to developing the most efficient EV battery enclosures. This clip idea is just one example of how we are constantly searching for ways to improve both manufacturing process and the end product.”

In fact, these clips are just one of the many innovative features of CSP and Teijin’s full-sized, multi-material battery enclosure consisting of a one-piece composite cover, one-piece composite tray with aluminum and steel reinforcements, and a mounting frame utilizing a structural foam for energy absorption. This enables a reduced frame thickness and weight, while improving crash performance.

By molding the cover and the tray each as one piece, CSP has created a system which is easier to seal and can be certified prior to shipment. All told, the CSP multi-material battery enclosure is 15% lighter than a steel battery box.  Although it is equal in weight to an aluminum enclosure, the CSP enclosure offers better temperature resistance than aluminum, especially if the company’s phenolic resin system advanced composite is used.

About Continental Structural Plastics

Continental Structural Plastics, a Teijin Group company, has provided leading-edge technologies in lightweight composite solutions for the automotive, heavy truck, HVAC and construction industries for 50 years. Headquartered in Auburn Hills, Michigan, CSP provides full-service engineering support, and holds multiple patents covering materials development and manufacturing processes. The company has operations on three continents and more than 4,300 employees. For more information, visit cspplastics.com.

About the Teijin Group

Teijin (TSE: 3401) is a technology-driven global group offering advanced solutions in the areas of environmental value; safety, security and disaster mitigation; and demographic change and increased health consciousness. Its main fields of operation are high-performance fibers such as aramid, carbon fibers & composites, healthcare, films, resin & plastic processing, polyester fibers, products converting and IT. The group has over 170 companies and around 20,000 employees spread out over 20 countries worldwide. It posted consolidated sales of JPY888.6 billion (USD 8.1 billion) and total assets of JPY1020.7 billion (USD 9.3 billion) in the fiscal year ending March 31, 2019. Please visit www.teijin.com.