The manufacture of SMC involves the compression of a glass and resin “pack” in a heated tool. The combination of pressure and heat means the material forms three-dimensional covalent bonds between polymer molecules. This process, known as cross-linking, is irreversible. Therefore, cross-linked materials cannot be melted, the result of which is a thermoset component with good strength and an ‘A’ class surface finish suitable for painting to an Automotive standard. Typical market applications are ‘A’ class body panels such as decklids and fenders for the Automotive sector and bonnets and exterior panels for the off highway sector i.e. engine covers.
A particular growth area has been the use of SMC in structural floor components in off highway vehicle cabs. In this application the strength of SMC combined with the ability to be moulded into the necessary form to suit the in cab design environment, means the customer can gain significant cost advantage over the traditional steel floor and plastic trim solution.
Adding integrated air con ducting, seat belt mounting points, brackets to support ancillary components and ‘A’ surface styling features make this a fully integrated solution.
The benefits of SMC
- Greater design freedom
- Lower system cost
- Weight reduction potential
- Excellent strength to weight ratio
- Potential to integrate electrical equipment
- Excellent thermal properties
- Electrical insulation
- Excellent dimensional stability
- Compatible thermal expansion to steel
- Excellent corrosion resistance
- Lower tooling cost
- Greater potential for part consolidation
- Excellent acoustic performance