塑胶原料种类及特性
ABS 丙烯腈-丁二烯-苯乙烯共聚物
典型应用范围:
汽车(仪表板,工具舱门,车轮盖,反光镜盒等),电冰箱,
大强度工具(头发烘干机,搅拌器,食品加工机,割草机等),电话机壳体, 打字机键盘,娱乐用车辆如高尔夫球手推车以及喷气式雪撬车等。
注塑模工艺条件:
干燥处理:ABS材料具有吸湿性,要求在加工之前进行干燥处理。建议干燥条件 为80~90C下最少干燥2小时。材料温度应保证小于0.1%。 熔化温度:210~280C;建议温度:245C。
模具温度:25…70C。(模具温度将影响塑件光洁度,温度较低则导致光洁度较低)。 注射压力:500~1000bar。 注射速度:中高速度。 化学和物理特性:
ABS是由丙烯腈、丁二烯和苯乙烯三种化学单体合成。每种单体都具有不同特性: 丙烯腈有高强度、热稳定性及化学稳定性;丁二烯具有坚韧性、抗冲击特性; 苯乙烯具有易加工、高光洁度及高强度。从形态上看,ABS是非结晶性材料。 三中单体的聚合产生了具有两相的三元共聚物,一个是苯乙烯-丙烯腈的连续相, 另一个是聚丁二烯橡胶分散相。ABS的特性主要取决于三种单体的比率以及两相 中的分子结构。这就可以在产品设计上具有很大的灵活性,并且由此产生了市场 上百种不同品质的ABS材料。这些不同品质的材料提供了不同的特性,例如从中等 到高等的抗冲击性,从低到高的光洁度和高温扭曲特性等。
ABS材料具有超强的易加工性,外观特性,低蠕变性和优异的尺寸稳定性以及很高 的抗冲击强度。
ABS
Generic Class
ABS (Acrylonitrile-Butadiene-Styrene)
Typical Applications
Automotive (instrument and interior trim panels, glove compartment doors, wheel covers, mirror housings, etc.), refrigerators, small appliance housings and power tools applications (hair dryers, blenders, food processors, lawnmowers, etc.), telephone housings, typewriter housings, typewriter keys, and recreational vehicles such as golf carts and jet skis.
Injection Molding Processing Conditions
ABS resins are hygroscopic and drying is required prior to processing. Suggested Drying drying conditions are 80 - 90 C (176 - 195 F) for a minimum of 2 hours. Resin moisture content should be less than 0.1% Melt Temperature Mold Temperature Resin Injection Pressure Injection Speed 200 - 280 C (392 - 536 F); Aim: 230 C (446 F) 25 - 80 C (77 - 176 F). (Mold temperatures control the gloss properties; lower mold temperatures produce lower gloss levels) 500 - 1,000 bar (7,250 - 14,500 psi) Moderate - high Chemical and Physical Properties
ABS is produced by a combination of three monomers: acrylonitrile, butadiene, and styrene. Each of the monomers impart different properties: hardness, chemical and heat resistance from acrylonitrile; processibility, gloss, and strength from styrene; and toughness and impact resistance from butadiene. Morphologically, ABS is an amorphous resin.
The polymerization of the three monomers produces a terpolymer which has two phases: a continuous phase of styrene-acrylonitrile (SAN) and a dispersed phase of polybutadiene
rubber. The properties of ABS are affected by the ratios of the monomers and molecular structure of the two phases. This allows a good deal of flexibility in product design and consequently, there are hundreds of grades available in the market. Commercially available grades offer different characteristics such as medium to high impact, low to high surface gloss, and high heat distortion.
ABS offers superior processibility, appearance, low creep and excellent dimensional stability, and high impact strength.
Major Manufacturers
Dow Chemical (Magnum grades), GE Plastics (Cycolac), Bayer (Lustran), BASF (Terluran), Chi Mei (Polylac), LG Chemical (Lupos), Cheil Synthesis.
PC 聚碳酸酯
典型应用范围:
电气和商业设备(计算机元件、连接器等),器具(食品加工机、电冰箱抽屉等),交通运输行业
(车辆的前后灯、仪表板等)。 注塑模工艺条件:
干燥处理:PC材料具有吸湿性,加工前的干燥很重要。建议干燥条件为100C到200C,3~4小时。加工
前的湿度必须小于0.02%。 熔化温度:260~340C。 模具温度:70~120C。
注射压力:尽可能地使用高注射压力。
注射速度:对于较小的浇口使用低速注射,对其它类型的浇口使用高速注射。 化学和物理特性:
PC是一种非晶体工程材料,具有特别好的抗冲击强度、热稳定性、光泽度、抑制细菌特性、阻燃特性以及抗污染性。PC的缺口伊估德冲击强度(otched Izod impact stregth)非常高,并且收缩率很低,一般为0.1%~0.2%。
PC有很好的机械特性,但流动特性较差,因此这种材料的注塑过程较困难。在选用何种品质的 PC
材料时,要以产品的最终期望为基准。如果塑件要求有较高的抗冲击性,那么就使用低流动率的 PC材料;反之,可以使用高流动率的PC材料,这样可以优化注塑过程。
PC Generic Class
PC (Polycarbonate)
Typical Applications
Electronic and business equipment (computer parts, connectors, etc.), appliances (food processors, refrigerator drawers, etc.), transportation (head lights, tail lights, instrument panels, etc.).
Injection Molding Processing Conditions
PC resins are hygroscopic and pre-drying is important. Recommended drying Drying conditions are 100 - 120 C (212 - 248 F) for 3 to 4 hours. Moisture content must be less than 0.02% prior to processing. Melt Temperature Mold Temperature Fill Pressure Injection Speed 260 - 340 C (500 - 644 F); higher range for low MFR resins and vice-versa 70 - 120 C (158 - 248 F); higher range for low MFR resins and vice-versa As high as possible for rapid molding Slow injection speeds when small or edge gates are used; high speeds for other types of gates Chemical and Physical Properties
Polycarbonate is a polyester of carbonic acid. All general-purpose polycarbonates are based on bisphenol A. The bisphenol A component of the molecule contributes to the high glass
transition temperature (150 C / 302 F). The rotational mobility of the carbonyl group within the molecule contributes to the high ductility and toughness of the resin.
PC is an amorphous engineering resin with exceptionally good impact strength, heat resistance, clarity, sterilizability, flame retardancy, and stain resistance. The notched Izod impact strength of PC is very high and mold shrinkage is low and consistent (.1 -.2 mm/mm). High molecular weight PCs (which translate to low melt flow rate) have higher mechanical properties, but processibility of such resins becomes difficult. The type of PC chosen for a particular application should be based on the desired criteria (for high impact properties, use a low-MFR PC; conversely, for optimal processibility, use a high-MFR PC).
The melt viscosities are typically Newtonian up to shear rates of 1000 1/s and decrease beyond that. The Heat Deflection Temperature Under Load is typically between 130 -140 C (266 - 284 F) and the Vicat Softening Point is typically around 155 C (311 F).
Major Manufacturers
Dow Chemical (Caliber), GE Plastics (Lexan), Bayer (Apec, Macrolon), DSM (Xantar), LNP (Lurbricomp, Thermocomp), Mitsubushi Engineering Plastics (Novarex), Teijin Chemical (Panlite).
PC/ABS 聚碳酸酯和丙烯腈-丁二烯-苯乙烯共聚物和混合物
典型应用范围:
计算机和商业机器的壳体、电器设备、草坪和园艺机器、汽车零件(仪表板、内部装修以及车轮盖)。
注塑模工艺条件:
干燥处理:加工前的干燥处理是必须的。湿度应小于0.04%,建议干燥条件为90~110C,2~4小时。 熔化温度: 230~300C。
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