Product Introduction SMC polyester/vinyl ester base sheet molding compounds
SMC is the abbreviation of Sheet Molding Compound, that is, sheet molding compound, the main raw materials are unsaturated polyester resin, thickener, initiator, crosslinking agent, low shrinkage additives, fillers, internal release agents, colorants and other mixtures impregnated with chopped glass fiber roving or glass fiber felt, and the two surfaces are combined with protective film (polyethylene or polypropylene film) to form a sheet molding material and various additives.
It is a sheet fiber-reinforced thermosetting composite. Typically contains 10-65% fiber reinforcement and is 12 mm or 24 mm fiber length for in-line cutting.
Although the molding process can also be used in the molding and injection molding processes, the most suitable for SMC is compression molding, in which the film is removed, cut to size, and then compressed. Whether it's its superior appearance or mechanical properties, the SMC is superior to the BMC.
SMC production process
SMC production equipment is divided into two parts: one is equipped with resin paste equipment, generally using vertical high-speed disperser, and the other is SMC re-benching machine
SMC characteristic
SMC is widely used in electrical appliances, auto parts, rail transit and other fields due to its superior performance in mechanical strength, rigidity, flame retardant, corrosion resistance, dimensional stability, ultraviolet resistance, low specific gravity and other properties.
Each of our formulations is specially customized according to your needs to stably meet your various needs for product performance and processability. We have developed special SMC formulations that can be used for injection molding.
According to your requirements, we can provide UL certification, ROHS certification and other certifications and test reports for formulas.
Comparison table of thermosetting and thermoplastic properties

Light weight and high strength


SMC/BMC is lighter than steel, aluminum, etc., and its relative density is generally 1.3~2.0g/cm3, only 1/4~1/6 of ordinary steel, and 1/3 lighter than aluminum alloy. It is 15%-50% lighter than steel, which can achieve lightweight goals, and has good impact energy absorption, and has high tensile strength, bending strength and impact toughness.

Plenty of design freedom

The flow characteristics and molding process of SMC/BMC materials determine that many parts can be molded in one go, which can reduce the number of molds and tooling, welding, assembly and other processes, thereby significantly reducing costs and realizing low-cost operation of low-volume parts.

Strong corrosion resistance

SMC/BMC is inherently corrosion-resistant, so it does not need to be phosphated for corrosion protection and improved bonding properties.

Excellent heat resistance and paintability

SMC/BMC products have good heat resistance. After the product is demolded, it can maintain dimensional stability within -50~200°C. Excellent heat resistance to meet the use of automotive parts. SMC material is the most suitable material for steel plate spraying technology. SMC has a similar coefficient of thermal expansion and heat resistance as steel, and the coating can be cured at the same oven temperature as steel.

Injection molding
1. Thermosetting molding is almost the same as thermoplastics, thermosetting materials, hot molds, and cold materials. 2. It is suitable for mass production of small structure products. 3. It is more suitable for products with small and complex geometries that do not require high strength.
Compression molding
1. The ideal process to maximize the performance strength of thermoset composites. 2. Low glass fiber damage (no screws, no ram shear) and low residual pressure on the product (no obstructing stress, smooth fluidity, the best effect). 3. It is suitable for pressing products with a large area, and can press products with complex shapes and large thicknesses. After the product is formed, it can be demolded while it is hot.