av日韩国产一区二区三区-av日韩国产在线-av日韩欧美高清在线观看-av日韩欧美视频在线-av日韩人妻黑人综合无码-av日韩熟妇在线

信息反饋
留言板

PC characteristics and injection molding process

發(fā)布時(shí)間:2012-01-08 15:47:50

PC the outstanding performance, high transparency, impact toughness, good creep, using temperature range wide, PC technological characteristic is: melt viscosity shear rate of the sensitivity of the smaller, and the sensitivity of temperature, no significant melting point, molten body viscosity, high temperature resin easily hydrolyzed, products easy to crack. According to these characteristics, we special attention should be paid to differentiate between the: to increase the melt flow, not by increasing injection pressure and improve injection temperature should be adopted to achieve. Requirements of mould flow, gate short and thick, to reduce the pressure of fluid loss, and at the same time higher injection pressure. Resin in forming to fully before the dry processing, make its water content control under 0.02%, in addition, in the machining process of resin insulation measures should be taken to, in case to moisture absorption. Need not only reasonable products design, still should correctly master the molding process, such as improving mould temperature, the products for post-treatment can reduce or eliminate stress. Depending on the product of the different situations timely reset process parameters.

    Here's molding process

    1, injection temperature must be integrated products shape, size, die structure. Products performance, requirements and so on various aspects of the situation into consideration to make. General use in molding temperature in 270 ~ 320 ℃, and between the high temperature of the material such as more than 340 ℃, the PC will appear decomposition, products dark, the surface appear silver article, dark, black spots, bubble, defects, and physical and mechanical properties also significantly.

    2, injection pressure to the PC products of the physical and mechanical properties, stress, molding shrinkage rate, etc have certain effect to the appearance of the products and stripping sex have a major influence, too low or too high injection pressure will make products appear some defects, general injection pressure control in the 80-120 MPa between the thin wall, long process, complex shape, gate of smaller products, in order to overcome the resistance of the melt flow, for timely full of cavity, just choose higher injection pressure (120-145 MPa). To get a complete and smooth surface of products.

    3, holding pressure and the holding time holding pressure of the size and the length of time the pressure of the internal stress of PC products have great influence, holding pressure is too small, small shrinkage effect to fill a vacuum bubble or surface appear shrink concave, holding pressure is too large, gate to produce larger internal stress around, in actual processing, often in high temperature material, low pressure solution to. The holding time choice should inspect the thickness of the products, gate size, mold temperature, etc and decide, general small and thin goods does not need a long the holding time, on the contrary, large, thick products the holding time should be long. The pressure the length of time can be through the gate sealing the test time to identify.

    4, injection speed on the performance of the PC products without obvious effects, in addition to thin, small runner, deep hole, long process products outside, generally USES the medium speed or slow processing, the best is the multi-level injection, general use a slow-fast-slow multilevel injection mode.

    5, mold temperature general control in the 80-100 ℃ can, to complex shape, thinner, demand higher products, but also can be increased to 100-120 ℃, but no more than die heat distortion temperature.

    6, screw speed and back pressure due to melt viscosity PC larger, from favorable plasticizing, favorable exhaust, favorable machine maintenance, prevent screw overload, to screw speed requirements cannot too tall, general control in 30 to 60 r/min advisable, and back pressure control in the injection pressure between 10-15% of advisable.

    7, PC in injection molding process to strictly control the release agents use, at the same time, the use of raw again no more than three times, use should be 20% or so.

主站蜘蛛池模板: 91在线视频免费观看 | 国产在线无遮挡的免费视频 | 成无码网在线观看 | 后入内射国产一区二区 | 国产成人一区二区三区高清 | 国产高潮流白浆免费观看 | 国产动漫一区二区三区无码 | 精品系列人妻无码 | 国产色欲女人乱免费视频 | 97人人夜夜视频精品 | 国产欧美日韩小视频高清 | 国产成人女人毛片 | 国产对白俱乐部交换在线播放 | 国产美女黄网站免费视频 | 精品国产一级二级三级在线 | 国产高清在线精品一区在线 | 动漫精品中文字幕无码第一页 | 妓女妓女一区二区三区在线观 | 91久久精品亚洲中文字幕无码 | 国产精品一区二区三区dbuen | 国产在线精品一区二区不卡顿 | 91国语精品福利自产拍 | 成人黄免色a | 国产午夜精品福利久久 | 国产精品三级久久久久久电影 | 91精品国产麻豆国产自产在线 | 国产午夜福利三级 | 国产宾馆精品在线播放 | 99久久久无码国产精精品免费 | 国产精品民宅偷窥盗摄 | 91蜜桃国产成人精 | 国产精品美女一区二区三区 | 高潮毛片无遮挡高清视频播放 | 国产91最新欧美在线观看 | 国产精品日韩欧美在线观看 | 91久久另类重 | 岛国一区二区三区在线观看视频 | 国产精品女同一 | 精品国产三级a∨在线欧美 精品国产三级a∨在线无码 | 激情都市综亚洲精品综合 | 91麻豆国产福利在线观看 |