SMC Material

SMC Composite Material (Sheet Molding Compound) is formed by one-time high-temperature compression molding. It features high mechanical strength, light weight, corrosion resistance, long service life, high insulation strength, arc resistance, flame retardancy and excellent sealing performance.

With flexible product design, easy large-scale production, safety and aesthetic advantages, it provides all-weather protection and meets the needs of various harsh environments and outdoor engineering projects. It overcomes the defects of outdoor metal enclosures such as easy rusting, short service life and poor thermal insulation. It is widely used in telecommunications, electric power, railway and other fields.

1. SMC Insulation Board (Unsaturated Polyester Glass Fiber Reinforced Molding Compound)

SMC insulation board is pressed from unsaturated polyester sheet molding compound. It has uniform color, arc resistance, FV0 flame retardancy, low water absorption, excellent leakage resistance, stable dimensional tolerance, small warpage, high dielectric strength and voltage resistance.

It is used for various insulation plates and structural parts of high and low voltage switchgears. Standard size of SMC board: 1000mm×2000mm.

SMC insulation materials have passed RoHS environmental protection test and the inspection by Guilin High Voltage Research Institute. At present, our company has established cooperation with well-known switchgear manufacturers such as Siemens, Schneider, Toshiba Baiyun and Senyuan Electric, supplying qualified products for the electrical industry.

2. Application Fields of SMC Materials

Electrical & Electronic Industry

Partition boards, lining plates, insulating supports, brackets, arc extinguishing shields, arc extinguishing cylinders, various insulators, arc extinguishing pieces, contact bases, busbar clamping plates, motor terminal boxes, electricity meter boxes, etc. for all kinds of switchgears.

Automotive Industry

Automotive bumpers, mudguards, spare tire bins, seats, instrument panels, anti-glare plates and more.

Construction Industry

High-rise building water tanks, sanitary ware, decorative panels and other construction products.

Railway Industry

Signal lamps, carriage window frames, signal box housings, etc.

Characteristics & Advantages of SMC Materials in Compression-molded Auto Parts

1. Light Weight

For the same component, SMC composite parts are 20-30% lighter than steel parts. It meets the automotive industry’s demand for weight reduction while ensuring structural strength, making it an ideal energy-saving material for the automotive industry.

The application of SMC parts also reduces fuel consumption, saves energy and benefits environmental protection.

2. Excellent Physical Properties

Its physical performance is comparable to metal materials, and it maintains stable mechanical properties even under high temperature conditions — far superior to ordinary thermoplastics. It is an ideal substitute material for steel.

3. High Integration & High Design Freedom

The flow characteristics and molding process of SMC enable one-step forming of complex parts such as positioning parts, connectors, reinforcing ribs, flanges and holes.

It reduces the quantity of molds and tooling, as well as welding and assembly procedures, greatly lowering production costs and enabling low-volume production at low cost.

4. Good Corrosion Resistance, Bending Performance & High Reliability

SMC itself is corrosion-resistant, requiring no phosphating treatment for anti-corrosion or bonding improvement. Compared with metal plates, SMC reduces costs and energy consumption.

It is uniquely suitable for auto parts used in harsh outdoor conditions. Compared with steel and aluminum plates, SMC panels have better resistance to denting from external impact and better rebound performance.

5. Outstanding Heat Resistance & Paintability

SMC products maintain dimensional stability within -50℃ to +200℃ after demolding.

SMC matches the thermal expansion coefficient and heat resistance of steel, adapting perfectly to automotive spraying technology. Painted SMC parts can complete coating curing at the same baking temperature as steel parts.

It also has good process adaptability: even if required to pass through phosphating lines due to production process constraints, SMC can fully meet the requirements, and SMC parts are also compatible with ED electrophoretic coating systems.

Sheet Molding Compound (SMC)

SMC is the abbreviation of Sheet Molding Compound. Its main raw materials include special SMC yarn, unsaturated polyester resin, low-shrinkage additives, fillers and various auxiliaries.

It originated in Europe in the early 1960s, followed by the United States and Japan around 1965. China introduced advanced SMC production lines and technologies in the late 1980s.

With superior electrical performance, corrosion resistance, light weight and flexible engineering design, its mechanical properties are comparable to some metal materials. It is widely used in transportation, construction, electronics and electrical industries.

Applications of SMC

1. Automotive Industry

Suspension parts, front & rear bumpers, instrument panels;

Body parts: hardtop roofs, anti-slip floors, spoilers, sunshields, engine hoods;

Under-hood parts: wind deflectors, air intake covers, fan retainers, engine sound insulation panels;

Interior parts: door handles, instrument panels, steering rod components.

2. Railway Vehicles

Seats, tea table tops;

Railway carriage window frames, wall panels, ceiling panels, railway signal transponders.

3. Electrical & Telecommunication Engineering

Electrical enclosures: switch boxes, wiring boxes, cable distribution enclosures, terminal distributors;

Electronic engineering: antenna radomes, radar domes, printed circuit boards;

Electrical components: insulators, insulating operating tools, motor commutators;

Communication equipment: telephone housings, cable distribution boxes, telephone booths.

4. Construction Engineering

High-rise roof water tanks, purification tanks;

Sanitary ware: bathtubs, wash basins, waterproof trays, toilets;

Construction formwork and building components: wall panels, ceilings, door frames.

5. Other Fields

Containers, electric pole jackets, hammer & shovel handles, catering utensils, shelf pallets.

Packaging, Transportation & Storage

SMC molding compound is packed in composite film bags, 50kg per bag, then packed into cartons.

During transportation, avoid heavy pressure, high temperature, moisture and package damage.

Shelf life: 3–6 months from the production date, stored in a dry warehouse below 25℃ and away from direct sunlight. Products beyond shelf life can still be used after passing re-inspection.

Molding Process of SMC Molding Compound

Holding pressure time: 60–70s/mm

Molding pressure: 10–20MPa

Molding temperature: 135℃–145℃

The specific process depends on product and mold structure: thicker products adopt slightly lower temperature; more complex shapes require higher molding pressure.