Product Name:  Manufacturer Custom Acrylic Clear Transparent Part Plastic Mold Injection Mould Plastic PMMA

As a manufacturer with 20 years experience in mold and molding industrial, below is our opinion about the injection moulding for PMMA plastic parts:

1. PMMA plastic drying treatment: PMMA has a certain water absorption, its water absorption rate of 0.3-0.4%, and injection must be in the humidity below 0.1%, usually 0.04%. The existence of water makes the melt appear bubbles, gas lines, transparency, etc. So we're going to dry it. The drying temperature is 80-90ºC, and the time is more than 3 hours. Recycled materials in some cases can be used up to 100%, the actual amount depends on the quality requirements, usually more than 30%, recycled materials should avoid contamination which will affect the transparency and the nature of the finished product.

2. PMMA plastic injection molding machine selection: Because of the high viscosity of its melt, it needs a deep spiral groove and a large diameter nozzle hole. If the strength of the product is higher, it is necessary to use a large length-diameter ratio of the screw to implement low temperature plasticization. In addition, PMMA must be stored in a dry hopper.

3. Mold and Gate design: Mold temperature can be 60ºC-80ºC, the diameter of the main channel should be matched with the inner taper, the best Angle is 5° to 7°, if you want to injection 4mm or above products, the Angle should be 7°, the main channel diameter up to 8 to 10mm, the overall length of the gate should not exceed 50mm. For products with wall thickness less than 4mm, runner diameter should be 6-8mm for products with wall thickness greater than 4mm, runner diameter should be 8-12mm for edge, fan and vertical gate depth should be 0.7 to 0.9t(t is the wall thickness of the product), needle gate diameter should be 0.8 to 2mm; Low viscosity should choose smaller size. Common vent holes are 0.05 deep, 6mm wide, and demould inclination is 30 '-1° cavity part between 35' -1°30°.

4.PMMA plastic melt temperature: can be measured by air injection method: from 210ºC to 270ºC, depending on the information provided by the supplier. Exit the back seat, make the injection molding machine nozzle leave the main channel bushing, and then manually plasticize injection molding, which is air injection molding.

5.PMMA plastic injection speed and retention time: rapid injection can be used, but to avoid high internal stress, it is appropriate to use multi-stage injection, such as slow-fast-slow, etc., when injection thick parts, the slow speed is used;

 Note: If the temperature is 260 ° C, the retention time should not exceed 10 minutes; if the temperature is 270 ° C, the retention time should not exceed 8 minutes.