Phenomenon of weld marks in injection molding and solutions

Update:02-12-2020
Summary:

  Abnormal phenomenon product cause solution crack […]

 

Abnormal phenomenon product cause solution crack

1. The injection mold is too cold, adjust the temperature of the injection mold

2. The cooling time is too long, reduce the cooling time

3. The plastic insert is different from the shrinkage. Preheat the metal insert

4. The ejector installation is flat and not inclined, the ejector cross-sectional area is small or the distribution is improper. Adjust the number of ejector rods and their positions.

5. Insufficient production slope, difficult to demold

The mold release gauge is set to have a correct slope, and the product surface has ripples

1. The temperature of the material is low, and the degree of twist is large. Increase the temperature of the material

2. The injection pressure can be reduced, and the injection pressure for high temperature materials is less, otherwise, the injection pressure will be increased

3. The mold temperature of injection molded parts is low, or the temperature of the mold is increased to increase the injection pressure

4. The injection speed is too slow to increase the injection speed

5. The gate is too small, expand the gate appropriately

The brittle strength of the product decreases

1. The material temperature is too high, the plastic is decomposed, and the control is reduced, and the material temperature is low. The material stays in the barrel

2. The internal stress between the plastic and the insert is too large, and the hot preform is embedded to ensure that there is a certain thickness of plastic around the insert

3. Many times of plastic recycling control the ratio of recycled materials

4. Plastic water

Preheating and drying of raw materials, difficult to demold

1. Poor structure of the ejector mold for placement and assembly Improve the ejector design

2. Insufficient draft of the mold cavity, correctly design the injection mold

3. The mold cavity temperature is not appropriate, and the mold temperature should be properly controlled

4. There are joints or material storage in the mold cavity. Clean the injection mold

5. The molding cycle is too short or too long, suitable for the current period of plastic injection

6. No air intake holes in the core

Modification of the injection mold, product size is unstable

1. Engine oil or electrical system is unstable. Correct electrical or hydraulic system

2. The molding cycle is not the same, and the period is shaped into control and consistent

3. Temperature. time. Pressure changes based on control, consistent cost reduction

4. Plastic particles have different sizes, use uniform plastic

5. Uneven ratio of recycled bottoms and mixed materials to new materials. Control the mixing ratio to make it even

6. Uneven feeding

Control the uniformity of the material and adjust or level the parts peeling and layering

1. Hybrids of different plastics, a single-use plastic

2. The same plastic and different grades are mixed, and the plastic grade plates are made of the same material

3. Poor plasticization, increase the molding temperature

4. Mix in foreign matter, clean up raw materials, and remove impurities

Weld Line

1. The plastic temperature is too low. Increase the barrel. Temperature mold and nozzle spray degree

2. Too many gates, reduce pouring changes or gate positions

3. Excessive release agent Use atomized release agent. Reduce dosage

4. The injection speed is too slow to increase the injection speed

5. The mold temperature of injection molded parts is too low to increase the mold temperature

6. The injection pressure is too small to increase the injection pressure

7. Poor venting of injection molded parts, increase injection molding vents and dissatisfaction

1. The machine temperature nozzle and barrel are too low to increase the temperature of the barrel and nozzle

2. The mold temperature of the injection molded part is too low to increase the mold temperature of the injection molded part

3. The feeding amount is not enough, increase the feeding amount appropriately

4. The injection volume of the part exceeds the injection volume of the largest injection model. Choose an injection machine with a larger injection volume

5. Too mouth pouring and small flow, increase gate size appropriately

6. The injection pressure is too high for rapid injection or too low or too slow. Increase the injection pressure or increase the temperature to increase the injection speed

https://www.huaximould.com/

0
Contact US