The pmma of China pmma sheet extrusion line is the best organic synthetic transparent material, with good comprehensive mechanical properties, tensile strength, bending strength, and compression strength, which are higher than polyolefin and polystyrene, polyvinyl chloride and so on. Impact toughness is poor but also slightly better than polystyrene. The poured bulk polymerized PMMA has higher mechanical properties such as tensile, bending, and compression and can reach the level of engineering plastics such as polyamine and polycarbonate. PC/PMMA Optical Sheet Extrusion Line has good dielectric and electrical insulation properties, excellent arc resistance, and good ageing resistance, but its heat and cold resistance are not high.
Processing and molding of PMMA
PMMA can be processed by casting, injection molding, extrusion, thermoforming and other processes and has good post-processing properties.
China pmma sheet extrusion line Casting is used to form plexiglass sheets, rods and other profiles, that is, to create shapes by bulk polymerization. The products after casting, need to be post-treated. The post-treatment conditions are two h at 60°C and two h at 120°C.
2. Injection molding
Injection molding adopts the pellets obtained by suspension polymerization, and the molding is carried out on a standard plunger or screw injection molding machine. China pmma sheet extrusion line injection molding products also need post-processing to eliminate internal stress. The processing is carried out in a hot air circulation drying oven at 70-80 °C. The processing time depends on the thickness of the product, generally about four h.
China JWELL as manufacturer of extruder,Polymethyl methacrylate can also be extruded to prepare plexiglass sheets, rods, pipes, sheets, etc., with particles produced by suspension polymerization. The mechanical properties, heat resistance and solvent resistance, are not as good as those of casting profiles. Their advantages are high production efficiency, especially for pipes and other casting moulds. Difficult to manufacture profiles. Extrusion moulding can use a single-stage or two-stage vented extruder, and the screw length-diameter ratio is generally 20-25.
China pmma sheet extrusion line Thermoforming is the process of making plexiglass sheets or sheets into products of various sizes and shapes. The blanks cut into required measures are clamped on the mould frame, heated to soften, and then pressurized to make them Adhere to the mould surface to obtain the same shape as the mould surface. After cooling and shaping, the edge is trimmed to get the product. The pressurization can be done using vacuum drawing or direct pressurization of a punch with a profile.
Three. China pmma sheet extrusion line operation method
China pmma sheet extrusion line The use of a screw extruder includes a series of links such as machine installation, adjustment, commissioning, operation, maintenance and repair. Its use is daily in general machines, mainly in the drive motor and deceleration gear. However, the working system of the screw extruder is the extrusion system. Still, it has unique characteristics, and special attention should be paid to its features when using the screw extruder. The installation, adjustment and commissioning of the machine are generally clearly stipulated in the operating instructions of the extruder.
Maintenance and maintenance of China pmma sheet extrusion line
The screw extrusion system is maintained in two ways: daily and regular maintenance.
- Daily maintenance is a regular routine work, which does not occupy the operating hours of the equipment, and is usually completed during driving. The key is to clean the machine, lubricate the moving parts, tighten the loose threaded parts, check and adjust the motor, control instruments, working parts and pipelines in time.
2.The regular maintenance of China pmma sheet extrusion line is generally carried out after the extruder runs continuously for 2500-5000h. The machine needs to be disassembled to check, measure and identify the wear of the main parts, replace the parts that have reached the specified wear limit, and repair them. damaged parts.
3.It is not allowed to run empty to prevent the screw and the machine from rolling.
4.If an abnormal sound occurs during the China pmma sheet extrusion line operation, stop the machine immediately for inspection or repair.
5.Strictly prevent metal or other debris from falling into the hopper so as not to damage the screw and barrel. A magnetic part or a magnetic frame can be installed at the feeding port of the material entering the barrel to prevent iron debris from entering the barrel. The material must be sieved in advance to prevent the debris from falling into the material.
- Pay attention to the cleanliness of the production environment and do not allow waste impurities to be mixed into the material to block the filter plate, affecting the product’s output and quality and increasing the machine head’s resistance.
7.When the China pmma sheet extrusion line must be stopped for a long time, rust-proof grease should be applied to the working surfaces of the screw, machine, and head. The small screw should be suspended in the air or placed in a special wooden box and should be leveled with a wooden block to prevent the screw from being deformed or bruised.
8.Regularly calibrate the temperature control instrument to check the correctness of its adjustment and the sensitivity of the control.
9.Designate a particular person to be responsible for equipment maintenance. And the detailed records of each maintenance and repair are listed in the factory equipment management file.