产品详情
我国是世界上最大的ABS树脂消费国，自20世纪80年代以来，我国的ABS树脂消费量迅猛增长，近年来每年消费量已超过120万t。据业内专家估计，今后ABS制品的应用领域将进一步拓宽，其市场需求潜力巨大。
ABS塑料挤出成型工艺
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原材料干燥
ABS树脂有一定的吸湿性，含水量一般在0.3%～0.8%范围内，加工前需对其进行干燥处理，一般将ABS树脂在80～85℃恒温干燥4h左右即可，干燥后的水分含量应小于0.2%。若干燥不足，则制品表面会出现癍痕、水纹或起泡现象。若干燥时间过长或干燥温度偏高，会造成树脂结块、制品发黄。
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设备
采用单螺杆挤出机挤出，螺杆的长径比（LID）为18～22，压缩比为2.5～3；挤出机料斗可配置干燥预热装置，机筒可采取排气式结构。
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挤出机机筒与机头温度
在满足挤出机正常挤出条件下，机筒温度160～180℃，机头温度175～185℃。温度偏高时，熔体流动性好，但挤出波动太大且不稳定，难以保证挤出制品质量；温度过高，还易造成原料降解。连接器的温度一般比螺杆头部均化段的温度低5℃，或者同温。该温度对原料的流动性起决定作用，其温度偏高，原料易降解变色，挤出波动大；温度偏低，易堵塞排气口，使真空度下降，挤出型材表面出现气泡。
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冷却条件的控制
从口模挤出的型坯需采用及时、合理的冷却方式和恰当的冷却水温进行冷却定型，方能得到理想的制品。ABS型材挤出过程中冷却水温在14～18℃较为理想，有效水压应大于0.2MPa。在生产过程中，如果冷却水水温过高或水压偏低、水流量偏小，使型材在出定型模后温度偏高甚至发生后变形，应适当降低挤出速度，以确保冷却时间；如果冷却水温过低，会形成骤冷，容易使型材内部残留有内应力，在自然存放过程中产生后变形，或者引起牵引阻力过大甚至颤车。
China is the largest consumer of ABS resin in the world. Since the 1980s, the consumption of ABS resin in China has been increasing rapidly. In recent years, the consumption of ABS has exceeded 1.2 million tons.Industry experts estimate that the application of ABS products will be further expanded in the future, and its market demand potential is huge.
ABS resin extrusion molding process
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Drying of raw materials
ABS resin has certain moisture absorption, water content is generally within the range of 0.3% ~ 0.8%.Before processing, it needs to be dried, and the ABS resin is generally kept in a temperature of 80 ~ 85 to about 4h.After drying, the moisture content should be less than 0.2%.If the drying is not enough, the surface of the product will have a ripple, water pattern or bubbling phenomenon.If the drying time is too long or the drying temperature is too high, it will cause the resin caking and the product yellowing.
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Equipment
Using single screw extruder, the length diameter ratio (LID) of screw is 18 ~ 22, and the compression ratio is 2.5 ~ 3.Extruder hopper can be equipped with dry preheating device, and the cylinder can adopt exhaust structure.
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Temperature of the barrel and head of extruder
Normal extrusion temperature: the temperature of the cylinder is 160 ~ 180, and the head temperature is 175 ~ 185.When the temperature is high, the melt flow is good, but the extrusion fluctuation is too large and unstable to ensure the quality of extrusion products.Connector temperature generally lower than the screw head of homogenization temperature of 5 ℃.
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Control of cooling conditions
In order to get the ideal product, the mold extruded bbbb must be cooled by a timely, reasonable cooling bbbbbb and proper cooling water temperature.The cooling water temperature in ABS extrusion process is ideal in 14 ~ 18 degrees, and the effective water pressure should be greater than 0.2mpa.
