PMMA 聚甲基丙烯酸甲酯

 

PMMA 聚甲基丙烯酸甲酯  

　

类别名:

典型应用范围:

汽车工业（信号灯设备、仪表盘等），医药行业（储血容器等），工业应用（影碟、灯光散射器)，日用消费品（饮料杯、文具等）。

注塑模工艺条件:

干燥处理：PMMA具有吸湿性因此加工前的干燥处理是必须的。建议干燥条件为90C、2~4小时。

熔化温度：240~270C。

模具温度：35~70C。

注射速度：中等

化学和物理特性:

PMMA具有优良的光学特性及耐气侯变化特性。白光的穿透性高达92%。PMMA制品具有很低的双折射，特别适合制作影碟等。

PMMA具有室温蠕变特性。随着负荷加大、时间增长，可导致应力开裂现象。PMMA具有较好的抗冲击特性。

PMMA

Generic Class

PMMA (Polymethyl methacrylate)

Typical Applications

Automotive (signal light devices, instrument panels, etc.), medical (blood cuvettes, etc.), industrial (video discs, lighting diffusers, display shelving, etc.), consumer (drinking tumblers, stationery accessories, etc.)

Injection Molding Processing Conditions

　

Drying

PMMA is hygroscopic and must be dried prior to molding. Drying at 90 C (194 F) for 2-4 hours is recommended. 

Melt Temperature

240 - 280 C (460 - 536 F) 

Mold Temperature

35 - 80 C (90 - 176 F) 

Injection Speed

Moderate 

Chemical and Physical Properties

Pellets for injection molding are made either by bulk polymerization of methyl methacrylate followed by extrusion and pelletization or by polymerization in an extruder. Formulations vary by molecular weight and physical properties such as flow rate, heat resistance, and toughness. Higher molecular weight grades are tougher than lower molecular weight grades. High flow formulations are generally preferred for molding.

Heat deflection temperature under load varies from 75 C (167 F) for high flow materials to 100 C (212 F) for low flow (high molecular weight) materials.

PMMA has excellent optical properties and weatherability. The white light transmittance is as high as 92%. Molded parts can have very low birefringence which makes it ideally suited as a material for video discs.

PMMA exhibits room temperature creep. The initial tensile strength is high but under long term, high stress loading, it exhibits stress craze. Impact strength is good but it does show some notch sensitivity.

Major Manufacturers

Cyro Industries, Atohaas (Plexiglas), BASF, Mitsubishi Rayon.