Resins for SMC/BMC
Compound materials known as SMC (Sheet Molding Compounds) and BMC (Bulk Molding Compounds) are produced using thermosetting polymeric matrices, the most commons are: Unsaturated Polyester or Vinyl ester resins.
Thermosetting resins form the matrix and the chemical backbone of SMC/BMC imparting the required properties. BMC looks like a homogeneous mass reinforced with glass or carbon fibers whereas SMC looks like a continuous sheet reinforced with glass or carbon fibers. SMC and BMC can be processed with different hot-melting technologies such as compression, injection and transfer. During the molding phase, thanks to the combined effect of heat and pressure, the material undergoes the crosslinking reaction and consolidating takes on the shape dictated by the mold geometry.
Among the main properties of SMC and BMC have certainly to be counted:
- Good mouldability, offering exceptional flexibility to the designer
- Weight reduction
- High dimensional stability
- Excellent electrical properties
- Good mechanical properties
- Fire retardancy (self-extinguishing)
- High surface quality with finishing "Top Class A"
- Low emissions
- Thermal resistance
- Chemical and corrosion resistance