What is the SMC material?

author: Zhejiang Resin Municipal Facility Co,.Ltd

2020-05-11

SMC is the abbreviation for Sheet Molded Compound, which is a high strength glassfiber reinforced thermoset molding material that is commonly compression molded. It combines glass fibers with unsaturated polyester, phenolic, vinyl, and acrylic modified resins, as well as fillers such as calcium carbonate, catalysts, pigments, stabilizers, and release agents to produce a high strength molding compound.

The glassfiber reinforced in SMC typically ranges from 10% to 60%, and the length of the glassfiber is usually between 1/2-inch and 1-inch (25mm). The manufacturing process of sheet molded compound is continuous and inline. The material is covered on both the top and bottom with a polyethylene or nylon plastic film to prevent self-adhesion. The paste is uniformly spread onto the bottom film, and chopped glassfiber is randomly deposited onto the paste. The top film is applied, and the sandwich is rolled to a predetermined thickness. The sheet is then allowed to mature for 48 hours. The SMC is delivered as sheets, typically 2.5-6mm thick and 1000-1200mm wide.

Compression molding takes place in a device called a “compression molding press,” which is usually hydraulically powered.The press usually consists of the upper and lower halves of the mold placed between two heated plates. Pre-heated SMC is placed into the lower half of the mold. The upper plate is then lowered, applying up to 2000 psi of pressure to the mold.Consistent application of heat and pressure causes the SMC to spread and properly fill every part of the mold. Compression molding can therefore be used to create even complex, detailed parts with great accuracy.

The most important and most frequently talked about advantage of sheet molding compound is its light weight when compared to other substances, including metals and even other polyesters such as bulk molding compound (BMC). SMC achieves a typical 25% weight reduction while maintaining similar strength to steel.

SMC’s lightweight nature does not necessitate any sacrifice in strength. It is sturdy and durable, capable of resisting impact even at high speeds. Combined with the straightforward nature and short production cycle of the compression molding process, parts made using SMC can be created in similarly high volume in a small amount of time.

SMC has the same coefficient of thermal expansion as steel and excellent corrosion resistance, making it an ideal alternative to steel in fluctuating temperature environments. SMC is ideal for large structural components due to its high strength-to-weight ratio. It allows modular design and construction site assembly, resulting in construction time and overall component cost savings.

Sheet molding compound is an extremely economical choice. Manufacturers can save money on all aspects of the production process, from minimal labor costs to reduced waste.

If you have any application requirements for SMC, please contact us.We will introduce the SMC manufacturing process in the next update, please stay tuned.

SMC Manufacturing Process

Differences between SMC, GRP and FRP manhole covers.

What is Conductive Plastic Pipe?

2023-10-25

Static electricity in plastic pipe systems.

2023-05-16

Features of SMC Composite Manhole Covers

2022-07-15

SMC Manufacturing Process

2021-12-19