PMMA 聚甲基丙烯酸甲酯

類別名:

典型應(yīng)用范圍:

汽車工業(yè)（信號(hào)燈設(shè)備、儀表盤等），醫(yī)藥行業(yè)（儲(chǔ)血容器等），工業(yè)應(yīng)用（影碟、燈光散射器)，日用消費(fèi)品（飲料杯、文具等）。

注塑模工藝條件:

干燥處理：PMMA具有吸濕性因此加工前的干燥處理是必須的。建議干燥條件為90C、2~4小時(shí)。

熔化溫度：240~270C。

模具溫度：35~70C。

注射速度：中等

化學(xué)和物理特性:

PMMA具有優(yōu)良的光學(xué)特性及耐氣侯變化特性。白光的穿透性高達(dá)92%。PMMA制品具有很低的雙折射，特別適合制作影碟等。

PMMA具有室溫蠕變特性。隨著負(fù)荷加大、時(shí)間增長(zhǎng)，可導(dǎo)致應(yīng)力開裂現(xiàn)象。PMMA具有較好的抗沖擊特性。

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