Enjection problems and troubleshooting (3)

HO Shing Traffic Engineering Co., Ltd.

Enjection problems and troubleshooting (3)

Enjection problems and troubleshooting (3)

. Weld or Meld line 結合線

A weekness or visible flaw created when two or more flow paths meet

during the filling process.

在填充過程中兩條或更多流路相遇時, 因流動尖端的溫度稍微下降,

而互不熔合產生的條痕及缺陷。

Possible Cause

Correction action

Material flow too slow
原料流動性不良

1. Increase melt temperature 提高原料溫度
2.  Increase back pressure to raise screw shaft speed 提高背壓加快螺桿轉速
3. Change material 更換原料

Mold temperature too low
模具溫度過低

Increase mold temperature 提高模具溫度

Injection speed too slow
射出速度太慢

Increase injection speed 增加射出速度

Injection pressure too low
射出壓力過低

Increase injection pressure 提高射出壓力

Contaminated material or mix with foreign material
原料不潔或滲有它料

Check material 檢查原料

Insufficient lubricant
潤滑劑不足

Less use Release agent

脫模油盡量少用或不用

Sprue and gate diameter too small
澆道及澆口太小

Increase lubricant

酌增潤滑劑

Air trapped in the cavity
模穴內空氣排除不及

Add vents or check if vents get clogged

增開排氣孔或檢查是否有阻塞

No overflow well
缺乏溢流井

Add overflow wells at the under end of welding line 在結合線處之下端增設溢流井

 

. Flow lines 流紋

A flow pattern as linear grooves or circular ripples on the surface of the molded

product which is the track of melt plastic flow within the cavity of the mold

成型品表面的直線凹槽或圓形波紋,是熔融塑料流痕在成品表面的現象

 

Possible Cause

Correction action

Improper material melt
原料熔融不佳

1. Increase melt temperature 提高原料溫度
2.  Increase back pressure to raise screw shaft speed 提高背壓加快螺桿轉速

Mold temperature too low
模具溫度過低

Increase mold temperature 提高模具溫度

Injection speed too slow
射出速度太慢

Increase injection speed 增加射出速度

Injection pressure too low or too high
射出壓力過低或過高

Adjust injection pressure 調整適度壓力

Contaminated material or mix with foreign material
原料不潔或滲有它料

Check material 檢查原料

Gate hole diameter too small
溢口過小

Increase dimension 加大溢口

Not even thickness of product 成品斷面厚薄相差太多

Redesign product or spill hole location 變更成品設計或溢口位置

 

. Silver streaks 銀紋(銀線)、氣瘡(起倉)

A shining line shaped patterns appear on the surface of the molded product.

在成形品表面,順著塑膠流動的方向出現銀白色條紋的現象

Possible Cause

Correction action

Moisture in material
原料含有水份

1. Dry material 原料徹底烘乾
2. Increase back pressure 提高背壓

Material temperature too high or overheat mold to produce air
原料溫度過高或模具過熱導致氣體產生

Reduce material temperature and mold temperature

降低原料溫度及模溫

Material contains additives like lubricant, dying pigment and so on
原料中含其他添加物如潤滑劑、染料等揮發物

Reduce useage or replace high temperature plastic

減少其使用量或更換耐溫較高之替代品

Poor mix among additives
原料中其他添加物混合不均

fully mix additives 徹底混合均勻

Enjection speed too fast
射出速度太快

Slow enjection speed 減慢射出速度

Mold temperature too low
模具溫度太低

Increase mold temperature 提高模具溫度

Material pellets not uniform
原料顆粒粗細不均

Use uniform pellets 使用粒狀均勻之原料

Poor flow path in the mold
原料在模內流程不當

  1. Adjust gate dimension and position

調整溢口之大小及位置
2. Keep mold temperature stable 模具溫度保持平均

 

.   Dull surface finish  成品表面不光澤

Product surface become clouded, it has low gross or Less reflection on molded surface.

產品表面變渾濁,表面有低粗反射或較少反射

Possible Cause

Correction action

Mold temperature too low
模具溫度過低

Increase mold temperature 提高模具溫度

Low filling material
原料用量不夠

1. Increase enjection volume 增加射出量
2. Extend enjection time 延長射出時間
3. Increase enjection pressure 增加射出壓力

Excessive release agent in the cavity
模內過多脫模油

Clean and dry it 擦拭乾淨

Moisture in the mold
模內壁有水

Wape and check if water leak out

擦拭並檢查是否有漏水

Rough wall of the mold
模內壁不光滑

Polish the mold 模具拋光