Shanghai Daoqin Plastics Co., Ltd.

        一, black spots more causes

         raw materials quality 差, black spots more;

         screw local hot, formed material material add heavy, material by belt/tape to material strip/profile in, formed to more;

         screw local 剪切太 strong/high, formed material material add heavy, material by belt/tape to material strip/profile in, formed to more;

         machine pressure large (包括堵塞, 滤网太 more, machine temperature degree low and other), material more, material material add heavy, material by belt/tape to material strip/profile in, formed to more;

         machine use year long, screw and machine 筒间隙 increase, machine viscous 附炭化 material increase more, extrusion time 推移, by belt/tape to material strip/profile in, formed to more;

        自然排 gas and true gas long time 不清理, 堆积 炭化 material increase more, rear 期连续 extrusion by belt/tape to material strip/profile in, formed to more;

         external ring or is formed other mixed 入, formed black spots more;

        口模(包括出 material and internal 死角)清理不 dry 净, formed black spots more;

        出 material 口不够 light slip (如, shallow and and other), long time can can material material, extrusion time 推移, by 逐渐炭化, again by belt/tape to material strip/profile in, formed black spots more;

        部 separation 螺纹原 parts loss bad (缺角, abrasion loss and other formed 死角), formed 死角处 material material add heavy, in rear 续连续 extrusion process in, by belt/tape to material strip/profile, formed black spots more;

        自然排 gas and true gas 不畅, formed screw inner material material 炭化, formed black spots more.

        二, formed product processing process issues analysis

        断 strip/profile generate 原不足:

         increase 滤网目数 or 张数;

        适当调 low machine speed or high material speed;

        适当 reduce extrusion processing temperature degree (machine or other 各区).

         external 杂质:

        检查 mixed material and material step/link equipment is 否清理 dry and is has mixed 入;

        尽 amount less add material or for material 进行初筛, remove 杂质;

         increase 滤网目数 and 张数;

        尽 amount cover/cap can can has material 掉落 孔洞(实 cover/cap or cover/cap).

         internal 杂质:

         machine pressure high (包括口模堵塞, 滤网太 more, machine temperature degree low and other), formed increase 而导致炭化 add heavy, material by belt/tape to material strip/profile in, in force function lower, formed strip/profile;

         extrusion machine local hot, formed add heavy, material by belt/tape to material strip/profile, in force function lower, formed strip/profile;

         screw local strong/high, formed material material local add heavy, material by belt/tape to material strip/profile, in force function lower, formed strip/profile;

         machine use year long, screw and machine abrasion loss, increase large, increase, machine viscous 附 炭化 material increase, extrusion time long, material by belt/tape to material strip/profile, in force function lower, formed strip/profile;

         true or 自然排 gas 口(此处包括垫 sheet/slice and 死角) long time 不清理, in material by belt/tape to material strip/profile, in force function lower, formed strip/profile;

         machine 头口模(此处包括出 material and machine internal 死角)未清理 dry 净, 口模里面含 has material or by belt/tape to material strip/profile, in force function lower, formed strip/profile;

         more 换滤网 time 间隔太 long, by 堵住, material material 出不, formed strip/profile.

         material material defect:

         extrusion temperature degree low or screw 剪切太 low, material material separation 塑化, material 疙瘩, in force function lower, formed strip/profile;

         formulation system in low melting point additives (包括EBS or PETS and other), in screw low or screw and machine 筒间隙 increase large and 剪切偏 low front lower, formed defect, formed strip/profile.

         raw materials material property 变化:

         blending separation in temperature degree, flow property in large 差异, due to flow property 不匹配 or full versus 容(包括 material 理缠结 and chemical reaction), upper this type of 叫“ versus separation 离”, “ versus separation 离” generally in blending extrusion 不会出现, relatively more in injection molding process in, if MFR versus large, in screw versus for relatively low front lower, can can 出现断 strip/profile;

         blending separation degree 变化: for 同一材 material 而言, if MFR decrease small, hardness, rigid property and 缺口变 large, has can can material molecular weight relatively front has large, formed degree large, in has processing temperature degree and process function lower, formed defect, improve/increase extrusion temperature degree or reduce machine screw speed can solution.

         material strip/profile or gas 不畅:

         processing temperature degree high or screw local 剪切太 strong/high or screw local hot, formed certain flame retardant and other additives separation understanding, 释放出 gas 体, true and will gas 体抽出, gas in material strip/profile 里面, in force function lower, formed strip/profile;

         material material 受潮严 heavy, processing water and 时经 自然排 gas and true troubleshooting, 汽体困 in material strip/profile, in force function lower, formed strip/profile;

        自然排 gas or true gas 不畅(包括堵塞, gas, sheet/slice high and other), formed has gas (or 汽)困 in material strip/profile 里, in force function lower, formed strip/profile.

         material material rigid property large, water cold or water more, 牵引不匹配:

         material material rigid property large, water temperature low, water more, machine 头 出 material very soft, water 则立刻变 non hard, in force 不匹配 function lower, formed strip/profile —— this type of phenomenon 常出现 in PBT or PET add 纤, PC add 纤, AS add 纤, ABS add and other crystallization speed degree non fast or rigid property non large material, especially is small machine 做实验 relatively heavy, improve/increase water temperature, reduce water amount, let pellet cutting machine material strip/profile maintain soft/flexible degree, can solution.

        滤网目数 low or 张数不够:

         this type of phenomenon 常出现 in upper machine pressure 不足, external and internal 杂质 时候.

        三, pelletizing issues analysis

        排 gas defect:

        排 gas (or 汽)不畅: due to 自然排 gas or true gas 不畅(can can material water heavy, can can flame retardant and other additives separation understanding, also has can can true 空堵塞 or true small or gas or true sheet/slice 垫 太 high and other causes), formed pellets in in gas (汽)体, formed 空心.

        塑化 defect:

         processing temperature degree low, material material full 塑化, light 者(small 孔)造 formed pellets 空心, heavy 者(large 孔)造 formed strip/profile;

         low melting point additives (包括EBS or PETS)太 more, in screw 剪切偏 low (例如, 2号线 production 普通ABS, EBS不 can more, more 出现“ gas 孔”) front lower, formed material material defect, formed 空心;

         low melting point additives (包括EBS or PETS)太 more, in screw and machine 筒间隙 increase large (例如, 1号线 production 普通ABS, has 时候EBS也不 can more, more 出现“ gas 孔”) or screw 剪切偏 low front lower, formed defect, formed 空心.

         water temperature low: cooling water temperature low, material material water shrinkage, formed shrinkage 孔, 例如做PP type product ——此 type phenomenon main/primary for crystallization type plastics; generally lower, crystallization type plastics (如PP, PA, PBT and other)宜 using/adopting low water temperature, non crystallization type plastics (如ABS, PC/ABS, HIPS and other) using/adopting high water temperature.

        四, 自然排 gas 口, true material

        自然排 gas material:

        喂 material speed and machine speed 不匹配, reduce material speed or improve/increase machine speed;

         add material to 自然排 gas 口 含区域 temperature degree low, material material 没塑化, in screw pressure function lower, formed material;

        自然排 gas 口附近 temperature degree high, material material degree heavy decline, screw slip, material material can and by 输送至 front 段, in rear material pressure function lower, formed material;

         screw 自然排 gas 口位置 and machine 筒 自然排 gas 口位置不 versus 匹配, formed material;

        此处未设置反 toward 输送元 parts or toward combined block, can reduce 自然排 gas 口螺槽 pressure, in rear material pressure function lower, formed material.

         true material:

         true force large, material material true pipeline, formed material;

         screw true 空位没 has 设置反 toward 输送元 parts or toward combined block, can reduce true 空段螺槽 pressure, in true function lower, formed material;

         true temperature degree high, material material degree heavy decline, screw slip, material material can and 时输送至 front 段, in true force function lower, formed material;

         extrusion processing temperature degree low, material material 未塑化 or flame retardant and other additives to in resin in separation dispersion, in true force function lower, formed material;

         screw combined combined 理, 位置也匹配, temperature degree and machine and material speed 也匹配 front lower, true sheet/slice low, in material pressure and true force function lower, formed material;

         machine pressure large (causes 包括: 口模堵塞, 滤网太 more, machine temperature degree low and other), formed increase, in true force function lower, formed material.

        五, material 斗架桥

         filler more, 吸潮, poly, formed mixed combined material and material 斗壁摩 scratch increase large, add “白油” and other liquid outer lubricant, reduce mixed combined material and material 斗壁以 and mixed combined material between scratch, can solution;

         mixed combined material block (包括 high temperature block and liquid additives add more block), reduce dry temperature degree or high mixed time, decrease/reduce liquid additives add amount, add for “油状” material tool has absorption function powder resin or additives (如, high powder, AS powder material, PP powder material and other), can solution.

        六, lower material 架桥

         main/primary is certain processing additives melting point low, 一区, processing temperature degree high, material material in material material soft 化, viscous in equipment 壁, formed rear lower material difficult, reduce 一区, processing temperature degree, can solution.