模具在注塑加工時會存在著質(zhì)量問題,究其原因是怎么樣的呢?下面就讓
濟南注塑加工廠家為您簡單講一講吧。
There will be quality problems in the injection molding process. What is the reason? Now let Jinan injection molding factory give you a brief introduction.
在注塑過程中如發(fā)現(xiàn)塑料制品的幾何形狀不穩(wěn)定、外形尺寸誤差比較大,則可能是模具內(nèi)腔的壓縮比比較小;模具口模定型部分長度尺寸比較小;定徑套變形或者是模具體溫度不均勻。
In the process of injection molding, if it is found that the geometric shape of the plastic product is unstable and the overall dimension error is relatively large, it may be that the compression ratio of the inner cavity of the mold is relatively small; The length and size of the shaped part of the die are relatively small; The sizing sleeve is deformed or the mold temperature is not uniform.
如看到制品表面發(fā)黃,經(jīng)常出現(xiàn)焦斑現(xiàn)象,則模具中的分流錐的擴展角度可能比較大,造成熔料流阻力大;模具熔料流道腔內(nèi)可能有滯流區(qū),料流不通暢;流道腔內(nèi)有阻流異物。
If the surface of the product is yellow and the phenomenon of focal spot often occurs, the expansion angle of the shunt cone in the mold may be relatively large, resulting in large resistance of melt flow; There may be a stagnant area in the mold melt channel cavity, and the material flow is not smooth; There are flow blocking foreign matters in the channel cavity.
如制品表面縱向溝紋不間斷,則可能有異物卡在流道腔內(nèi)某一部位,定型部位有劃傷痕跡、毛刺或有嚴重磨損粗糙面。
If the longitudinal grooves on the surface of the product are uninterrupted, there may be foreign matters stuck in a part of the flow channel cavity, and there are scratches, burrs or severely worn rough surfaces on the shaped part.
原料中含水份較多或揮發(fā)物含量過高。成型操作方面:熔體溫度過低,低溫熔體的分流匯合性能較差,容易形成熔接紋;熔體注射壓力過低,使得注射速度過慢,熔體在型腔中的溫度不相同,這時熔體在分流匯合時就易產(chǎn)生熔接紋。注塑機設計和塑膠件設計方面:在此不作講述。
The raw materials contain too much water or too much volatile matter. Molding operation: the melt temperature is too low, the low-temperature melt has poor shunting and confluence performance, and it is easy to form fusion lines; The injection pressure of the melt is too low, so the injection speed is too slow, and the temperature of the melt in the cavity is different. At this time, the melt is easy to produce fusion lines when it is divided and merged. Injection molding machine design and plastic parts design: not described here.
波紋:模具方面:與熔接紋大同小異,但需特別強調(diào)的是冷料對波紋影響大。原料方面:熔體流動性差是產(chǎn)生波紋的主要原因,如:PMMA、PC、AS等透明料制品;當ABS材料是經(jīng)改性為共聚型高分子材料時,如加工溫度過高,樹脂及潤滑劑會產(chǎn)生揮發(fā)性氣體,這些氣體使塑膠件表面形成波紋。成型操作方面:注射速度過小;熔體流速過大;模具溫度偏低。
Corrugations: in terms of molds, it is similar to the welding lines, but it needs to be emphasized that the cold material has a great impact on the corrugations. Raw materials: poor melt fluidity is the main reason for ripple, such as PMMA, PC, as and other transparent materials; When the ABS material is modified into a copolymer polymer material, if the processing temperature is too high, the resin and lubricant will produce volatile gas, which will form ripples on the surface of the plastic part. Molding operation: the injection speed is too low; The melt flow rate is too large; The mold temperature is low.
How to find quality problems from injection molds during injection molding is the general content. You can visit the website http://m.55film.com Ask for solutions to more problems.