Transparent acrylic square small coffee table
1, polymethyl methacrylate contains polar side methyl, with a more obvious moisture absorption, water absorption rate is generally 0。3%-0。4%, before molding must be dry, drying conditions are 80℃-85℃ under the dry 4-5h。
2, Polymethyl methacrylate in the molding process temperature range has a significant effect of non-Newtonian fluid characteristics, melting viscosity with the increase of shear rate will be significantly reduced, melt viscosity on the temperature changes are also very sensitive. Therefore, for the molding process of polymethyl methacrylate, the increase of molding pressure and temperature can obviously reduce the melt viscosity, and obtain better fluidity.
3. Methyl methacrylate began to flow at a temperature of about 160 ℃, starting to decompose at a temperature higher than 270 ℃, with a wide processing temperature range.
4, polymethyl methacrylate melt viscosity is high, cooling rate is fast, products are prone to internal stress, so molding when the process conditions control requirements are strict, the product molding also needs to be post-treatment.
5, polymethyl methacrylate is amorphous polymer, shrinkage and its range of change are small, generally about 0。5%-0。8%, is conducive to the molding of high dimensional accuracy of the plastic parts。
6, Polymethyl methacrylate cutting performance is very good, its profile can be easily machined for a variety of requirements of the size.