Spray Transfer Molding (STM) is a forward-looking manufacturing technology that has garnered widespread attention. In essence, it is a fast and efficient process used to manufacture lightweight composite materials. During this process, fabric is impregnated outside the mold using a high-pressure spraying process, then molded in a compression unit. The key to this process lies in programmable robots that hold dry fiber mats and operate in an optimized and controlled spray pattern. It is then sprayed using a high-pressure nozzle head atomizing the spray polyurethane, the robot will lay down the impregnated blank into the tool to be fully molded and cured. The process is designed to scale from initial ideation and experiments to actual automotive production components.
Using this technology brings numerous advantages. Firstly, it employs sustainable materials such as bamboo, jute, and other materials with a high content of bio renewable content, aligning with today’s emphasis on environmental protection and sustainability. Secondly, the process has a high throughput and low demolding times are the best on the market, significantly enhancing production efficiency. Additionally, the technology offers the capability for optimized designs to match OEM specifications. Lastly, top-notch technical support and open lab facilities are provided for prototype production.
The Mercedes Benz Smart Fortwo is an example of this technology in action, employing a honeycomb sandwich structure with a class A film that’s 30% lighter than the standard roof on the previous model. This achievement underscores the potential of this technology in the automobile industry. Apart from this sector, STM can be applied in areas such as construction, consumer goods, and industrial manufacturing. In automotive production, its applications are diverse, including door interiors, arm rests, load floors, sun shades, hatchbacks and package shelves.
An innovative product developed by BASF based on STM process is the Polyurethane Composite Battery Pack Solution. This solution has not only been tested in large-scale production but also possesses flame-retardant, lightweight, and efficient properties. This battery pack has not only passed flame retardancy tests but also utilized micro-cellular foaming technology to reduce component density while maintaining sufficient mechanical performance. Compared to traditional polyurethane composite material molding processes, BASF’s STM process does not require preforming, leading to higher production efficiency. Consequently, it has become an ideal solution for weight reduction and cost savings in EVs.
Overall, the application of STM technology has brought new possibilities to various industries and plays a vital role in driving sustainable development and innovation.
