The Technological Properties of Acrylic Sheet
1. Polymethyl methacrylate contains polar side methyl, with a more obvious hygroscopicity, water absorption is generally 0.3% -0.4%, must be dried before drying, drying conditions are 80 ℃ -85 ℃ dry 4-5h.
2. Methyl methacrylate in the molding process within the temperature range of significant non-Newtonian fluid properties, melt viscosity increases with the shear rate will be significantly reduced, the melt viscosity is also sensitive to changes in temperature. Therefore, for polymethyl methacrylate molding processing, improve the molding pressure and temperature can significantly reduce the melt viscosity, to achieve better mobility.
3. The temperature at which the polymethyl methacrylate starts to flow is about 160 ° C and the temperature at which the decomposition begins is higher than 270 ° C and has a wide processing temperature interval.
4. Methyl methacrylate melt viscosity is higher, the cooling rate and faster, easy to produce internal stress products, so the molding process conditions on the strict control requirements, after forming the product also need to post-processing.
5. Poly (methyl methacrylate) is an amorphous polymer, shrinkage and its range of variation are small, generally about 0.5% -0.8%, is conducive to the formation of high dimensional accuracy of the plastic parts.
6. Methyl methacrylate cutting performance is very good, the profile can be easily machined to a variety of required size.
