First, the problem: plastic overflow
Cause: The pressure is not enough, resulting in flashing under too high injection pressure.
Solution:
1. Reduce the injection pressure.
2. Reduce the resin temperature.
3. Use high viscosity grade materials.
4. Reduce the mold temperature.
5. Grind the mold surface where the overflow occurs.
6, using a harder mold steel.
7, improve the clamping force.
8. Adjust the joint surface of the accurate mold.
Second, the problem: plastic bubbles
Cause: The formation of bubbles is due to insufficient filling or low pressure. Under the rapid cooling of the mold, the fuel at the corner of the cavity is pulled, resulting in a volume loss.
Solution:
(1) Increase the energy of injection: pressure, speed, time and amount of material, and increase the back pressure to make the filling full.
(2) Increasing the temperature of the material flow smoothly. Lower the material temperature to reduce shrinkage, and appropriately increase the mold temperature, especially the partial mold temperature at which the vacuum bubble is formed.
(3) The gate is placed in the thick part of the part to improve the flow of the nozzle, the runner and the gate, and reduce the consumption of the press.
(4) Improve the mold exhaust condition.
Third, the problem: the plastic is a wave
Cause: Due to the narrowness of the gate or other parts, the molten plastic pushes the solidified parts forward, and the surface is corrugated.
Solution: 1. Increase the injection diameter 2. Increase the nozzle and mold temperature 3. Increase the height of the barrel 4. Accelerate the injection speed 5. Slow down the injection speed 6. Change the mold cooling water inlet position away from the gate.
Fourth, the problem: plastic has silver silk
Reason: There is a lot of water in the mold or the hot melt plastic in the storage tank has a large amount of vaporized water, or it may be the moisture caused by the chemical reaction of the additive, which is injected into the cavity together during the injection molding process. And pressed to the radial silver wire pattern.
Solution:
1. Check if the plastic storage is appropriate.
2. Check the cooling pipe for leaks, avoid too sharp corner design, and reduce the depth of engraving.
3. Check the sealing degree of the injection value, check and replace the additives such as pigments.
4. Increase drying temperature and increase drying time
5. Increase back pressure, reduce back lock, and reduce injection speed.
V. Problem: Poor plastic interface
Cause: The plastic temperature is too low to melt, or due to insufficient gas excretion, two or more shunts are mixed to produce hairline or bubbles.
Solution: 1, increase the material temperature, increase the temperature of the injection 3, increase the injection speed 4, the peripheral line of the seam line cold storage tank 5, set the venting port 6, change the gate position or gate 7, do not use the release agent
Sixth, the problem: the plastic parts are hollow
Reason: Because the surface of the plastic contacts the low-temperature mold wall during solidification of the melt, the shrinkage concentrates on the thick-walled section to cause voids, or voids due to air entrapment.
Solution: 1. Increase injection pressure 2, extend injection time 3. Reduce barrel curing temperature 4. Expand gate 5, shorten flow path 6, adjust mold temperature 7, change gate position, and remove gas.
Seven, the problem: plastic parts are not enough or lack of material
Reason: Due to insufficient mechanical injection molding and plasticizing performance, the material flow is poor, the gate section is too thin, the mold wall is too thin or the air is poor.
Solution: 1. Increase the injection rate 2. Install the anti-leak valve screw 3. Increase the injection pressure 4. Improve the barrel, the nozzle curing and the mold temperature 5. Check whether the heating line is broken 6. Check whether the nozzle is blocked. , increase the circulation speed 7, improve the mold deflation ability 8, increase the gate cross section.
Eight, presenting the problem: extrusion molding plastic
Cause: The material temperature is too high, or the clamping force is insufficient.
Solution: 1. Reduce injection pressure and barrel curing temperature 2. Shorten injection time 3. Reduce injection speed 4. Change high clamping force machine 5. Modify clamping surface tight fit and clean mold surface 6. Switch to low viscosity material .
Nine, the problem: the surface of the plastic parts is dent
Cause: The surface of the plastic part is cooled by mistake, due to the surface dent.
Solution: 1. Increase the injection rate 2. Increase the internal pressure of the cavity (secondary pressure) 3. Reduce the solidification temperature of the cylinder 4. Increase the injection flow rate 5. Increase the injection speed 6. Increase the injection time 7. Make the mold temperature uniform.
X. Problem: The plastic parts are distorted
Cause: The plastic parts are distorted due to the residual stress relaxation of the injection molding.
Solution: 1. Reduce injection pressure 2, reduce the curing temperature of the barrel 3. Extend the cooling time 4. Adjust the wall thickness of the material and adjust the mold release lock 5. Add the mold release lock 6, change the gate position 7, and adjust the mold temperature.
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HENGSHUI YUZHENG IMPORT AND EXPORT CO., LTD. , https://www.yzironnails.com