BMC is the abbreviation of glass fiber reinforced unsaturated polyester thermosetting plastic, and it is currently the most widely used type of reinforced thermosetting plastic.
BMC Features and applications
BMC has good physical, electrical and mechanical properties, so it has a wide range of applications, such as the production of mechanical parts such as intake pipes, valve covers, and common manhole covers and rims. It is also widely used in aviation, construction, furniture, electrical appliances, etc., which require earthquake resistance, flame retardancy, beauty and durability.
BMC Processing characteristics
1. Fluidity: BMC has good fluidity and can maintain good fluidity under low pressure.
2. Curability: The curing speed of BMC is relatively fast, and the curing time is 30-60 seconds/mm when the molding temperature is 135-145°C.
3. Shrinkage rate: The shrinkage rate of BMC is very low, between 0-0.5%. The shrinkage rate can also be adjusted by adding additives as needed. It can be divided into three levels: no shrinkage, low shrinkage, and high shrinkage.
4. Colorability: BMC has good colorability.
5. Disadvantages: the molding time is relatively long, and the product burr is relatively large.
BMC compression molding
BMC compression molding is to add a certain amount of molding compound (agglomerate) into a preheated mold, pressurize and heat, and then solidify and shape. The specific process is weighing→feeding→molding→filling (the agglomerate is under pressure It flows and fills the entire mold)→curing→(fully cured after keeping it at the set pressure and temperature for a certain period of time)→opening the mold and taking out the product→grinding the burr, etc.→finished product.
BMC compression molding process conditions
1. Molding pressure: 3.5-7MPa for ordinary products, 14MPa for products with high surface requirements.
2. Molding temperature: The mold temperature is generally 145±5°C, and the fixed mold temperature can be lowered by 5-15°C for demolding.
3. Mold clamping speed: the best mold clamping can be completed within 50 seconds.
4. Curing time: The curing time of the product with a wall thickness of 3mm is 3 minutes, the curing time with a wall thickness of 6mm is 4-6 minutes, and the curing time with a wall thickness of 12mm is 6-10 minutes.
Post time: May-13-2021
