Foam and sponge are versatile materials that lend themselves to producing cut parts that satisfy a multitude of automotive applications. From suppressing squeaks and rattles, to air management seals and baffles, these parts are an important component in today’s fuel efficient and lightweight vehicles. In this blog we examine the foam and sponge cut parts for automotive applications that CRG can supply.
About foam and sponge materials
Foam and sponge are distinct materials that exhibit different mechanical and physical properties which support a wide range of uses and purposes.
Foam rubber is produced when a gas is blown into a liquid mixture, creating numerous small bubbles. Sponge, on the other hand, consists of two types: open cell and closed cell. Open cell sponge is formed in a mold. Sodium bicarbonate is added to the uncured rubber material in the mold. The sodium bicarbonate “effervesces” to create a network of open and interconnected cells. Closed cell sponge, in contrast, is formed when released nitrogen gas creates bubbles that remain completely closed within the material. Closed cell sponges have a more solid, yet lightweight structure, while open cell sponges are softer and more breathable.
A hybrid material is semi-open cell foam which is created by physically bursting the closed foam cells during the setting process to create an amalgam product which is softer and easier to compress.
Foam and sponge materials may be made from a variety of rubber compounds. EPDM, silicone, and microcellular urethane (Poron®) are some of the more common types of foams and sponges which CRG uses to service automotive applications.
Foam and sponge materials: automotive applications
Because of their different properties and characteristics, foam and sponge materials will support a variety of applications. With their more solid structure, closed cell sponges are a preferred material to for the following applications:
- Thermal insulation
- Seals and gaskets which protect against the intrusion of moisture, UV light, or dirt
- Joint fillers and edge extrusions
Softer open cell sponges are usually preferred material for the following applications:
- Automotive trim
- Acoustic applications
With a wide range of foam and sponge material formulations available in the marketplace today, choosing the right material is important for ensuring that the finished part will perform as intended in the target application. Criteria that should be considered when selecting a foam or sponge material for an application includes the following:
- Service temperature range. The material chosen should be capable of withstanding the service temperature range that will be encountered within the application.
- Chemical resistance. Foam and sponge parts used in automotive applications can be exposed to fluids and lubricants. The material selected should be capable of withstanding any chemical attack resulting from contact with these media.
- UV and moisture resistance. Foam and sponge vehicle parts are often exposed to sunlight and weathering, which can result in ageing and degradation of the material.
- Compression set resistance. Compression set resistance is the ability of a foam or sponge to return to its original thickness after a compression load, under a specific time and temperature, is released. To ensure long-term performance and sealing, a foam or sponge with the appropriate compression set for the application should be selected.
- Flame retardance and safety. To ensure occupant safety, foams and sponges which retard flames and do not emit noxious fumes when burnt are preferred for vehicle applications.
- Manufacturability. Foams and sponges made from different compounds vary in their manufacturability for conversion into a finished part. Manufacturing considerations are an important part of material selection decisions.
In serving the needs of our customers with foam and sponge cut parts for automotive applications, CRG has a proven capability. We work with each customer early in their project to assist with part design and material selection. Parts are developed to meet all quality standards using a production product approval process (PPAP), and all parts are produced using CNC cutting technologies under the guidance of experienced operators.
In the production phase of a project, CRG uses proven processes while adhering to recognized quality standards, such as ISO 9001:2015, to ensure reliable and consistent part quality. In every project, we maintain our commitment to 100 percent on-time delivery, whether utilizing demand-pull replenishment or JIT scheduling.
CRG supplies parts which meet ASTM D1056 line call-outs, as well as the material specifications of major OEM’s, including those of General Motors, Ford, Chrysler, Nissan, Mazda, BMW, Honda, Toyota, Volvo, and Mercedes-Benz. In those cases where a new specification is required, we work with our supply chain partners to develop an appropriate solution that meets or exceeds all requirements. To find out more about the foam and sponge cut parts which CRG can supply, please contact our sales department at firstname.lastname@example.org.