Shanghai Daoqin Plastics Co., Ltd.

attention/notes: cooling speed degree fast slow 取决于材 material property can, thick and mold temperature degree high low.

injection speed degree fast / slow

injection speed degree fast: easy 出现焦斑, flash, internal bubbles or formed melt 喷射

injection speed degree slow: easy flow 痕, 熔接痕, and formed surface coarse 糙, gloss


转 pressure 点

how 确定转 pressure 点

generally 说, pressure is in holding pressure pressure lower product to 95％满时, injection to holding pressure 切换点. for/regarding thin product （如: belt/tape ）: generally to product 98％
for/regarding non balanced runner: generally is 70％-80％, specific 情况而定. 并建议 using/adopting slow - fast - slow more grade injection.

转 pressure high / low

转 pressure high: product 充模不足, 熔接痕, 凹陷, dimensions small and other

转 pressure low: flash, demolding difficult, dimensions large and other


holding pressure pressure

how holding pressure pressure

optimization holding pressure pressure generally is most low holding pressure pressure and most high holding pressure pressure in value.

most low holding pressure pressure: in 准确 转 pressure 点基础 upper, to 予一定 holding pressure pressure, product rigid 出现充模不足时 holding pressure

most high holding pressure pressure: in 准确 转 pressure 点基础 upper, to 予一定 holding pressure pressure, product rigid 出 现毛刺时 holding pressure pressure.

（ from most low and most high holding pressure pressure can to product process safety scope/range ）

generally 说:

PA holding pressure pressure =50% injection pressure  

POM holding pressure pressure = 80% injection pressure;

for/regarding dimensions requirements high product can to 100％ injection pressure

PP/PE holding pressure pressure =30-50％ injection pressure


holding pressure time

how holding pressure time

holding pressure time 确定以 gate cold is based on. through product heavy 确定.

holding pressure time long / short

holding pressure time long: effect/influence cycle

holding pressure time short: weight 不足, product internal 空洞, dimensions small

attention/notes: holding pressure pressure effect/influence holding pressure time long short. holding pressure pressure large holding pressure time long.


screw speed

预塑 target/goal is: obtain stability melt （即塑化 uniform, cold material, degradation, more gas 体）

how screw speed

as is 原则, screw speed 确定必 must make screw time, time and 射台 回退 time and short cooling time.

screw speed fast / slow

screw speed fast: 塑化不均（ from formed product cold material, 充模不足 and fracture and other ）, material separation understanding （ from formed 焦斑, Color Difference, fracture and other ）

screw speed slow: effect/influence cycle

cooling time

as is 原则, cooling time setting short good, product deformation, mold sticking, deep ejection is basic requirements.

and: screw speed:
PA<1.0m/s;
POM < 0.7 m/s;
PP/PE/PS < 1.3m/s;
ABS/PC/PMMA < 0.6m/s

back pressure

what is back pressure

back pressure is screw 预塑时, liquid pressure retardant screw rear force, its large small and other screw front melt for screw function force.

how back pressure

back pressure 确定取决于 different material property can, usually material supply provide.

generally 说: PA: 20-80 Bar; POM: 50-100 Bar; PP/PE: 50-200 Bar

how back pressure

back pressure high: material separation understanding; 流涎; need more long time

back pressure low: 塑化不均（ especially for/regarding masterbatch material ）, 塑化不实（ from formed product bubbles, and other ）

回吸 amount

how to 确定回吸 amount

回吸 amount 确定（结 combined back pressure 确定）以不流涎 is 原则

回吸 amount large / small

回吸 amount large: bubbles, 焦斑, material 垫不稳

回吸 amount small: 流涎, material 垫不稳（ due to 止回阀关不住）

clamping force

clamping force 确定

clamping force large small 取决于 type 腔投影面积 and injection pressure large small

clamping force large / small

clamping force large: gas 不畅（焦斑, 充模不足）, mold deformation

clamping force small: flash


melt temperature degree

how melt temperature degree

usually melt temperature degree 确定取决于 different material property can, material supply provide. （ use material melt temperature degree and mold temperature degree table/sheet ）

material temperature degree setting

melt temperature degree high / low

melt temperature degree high: material separation understanding （ from formed product bubbles, Color Difference, 焦斑, fracture and other ）

melt temperature degree low: material 塑化不均, melt inner cold material （ from formed 充模不足, cold material, product fracture and other ）

mold temperature degree

is what need mold temperature

无论 mold temperature degree high low, it function is is in stability production process in make mold 维持一定 temperature degree, cooling function.

true positive important mold temperature is mold type temperature degree, is mold temperature machine upper temperature degree. usually, in stability production process in type temperature degree to stability balanced, high 于显示 temperature degree 10 degree left right

（ for/regarding large mold in production front must make mold separation add hot, especially is thin 壁, long ratio very large product mold ）

mold temperature degree effect/influence what

会 effect/influence melt flow property and cooling speed degree.

因 is effect/influence flow property, from effect/influence product appearance （ surface quality, 毛刺） and injection molding pressure;

因 is effect/influence cooling speed degree, from effect/influence product crystallization degree, effect/influence product shrinkage rate and machine strong/high degree property can.

mold temperature degree high / low

mold temperature high: flow property good; crystallization degree high; shrinkage rate large （ from formed dimensions small ）; deformation; need more long cooling time

mold temperature low: flow property 差（ from formed flow 纹, 熔接痕）; crystallization degree low; shrinkage rate small （ from formed dimensions large ）