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Plastic blow molding products common surface quality defects and solutions

Author: HUAN Machinery     Publish Time: 2022-10-28      Origin: HUAN Machinery


Today, HUAN MACHINERY would like to share with you the common surface quality defects of plastic blow molding products and corresponding solutions.

In the process of blow molding production, even if we correctly operate the production process, the production of blow molding products will always appear a variety of quality defects. This is also troubling many plastic blow molding products manufacturers one of the problems.

extrusion blow molding machine

I There are black materials on the surface of plastic blow molding products: black spots, black lines, etc

1. Blow molding raw materials stay in the machine barrel or flow passage for too long, and the performance of raw materials changes

2. There are other impurities in the blow molding barrel

3. In the heating process of blow molding machine, the unstable heating temperature reduces the quality and performance level of blow molding raw materials

4 blow molding machine die mouth temperature difference is larger

5. The hydraulic oil leakage inside the die head contaminates the raw material and changes the performance of the raw material

6 blow molding screw, cartridge wear is serious, raw materials can not be uniform melting

7. The cooling water system of the mold is not perfect, resulting in large overall temperature difference of the mold

8. The mold exhaust is not good or complete, so that the excess air is accumulated in the cavity, causing the burning of raw materials

9. There is residual grease or lubricant inside the mold, which contacts the raw materials at high temperature, causing the raw materials to burn

10. The raw materials are of poor quality and have many impurities

11. Machine parameter Settings are chaotic and the temperature setting range is not accurate

60L machine

II Blow molding products have bubbles on the surface

1. The raw material of blow molding is wet. In the production process, the water in the raw material turns into water vapor and evaporates into the raw material through high temperature

2. The exhaust hole of the mold is blocked, resulting in obstructed exhaust, and the gas generated in the production process cannot be discharged smoothly, forming bubbles

3. Blow molding production cycle is too short, cavity gas can not be discharged quickly in time

4. The pressure parameter required by the machine for production is incorrectly set

5 blow molding screw speed is too fast

6. Screw back pressure is too low

7. Volatile additives are found in raw materials

ibc tank blow machine

III Blow molding products surface dark, low finish

1. The actual pressure in the process of blow molding does not meet the production requirements, so that the raw materials are not fully combined

2. The temperature of the barrel is too low, and the raw material does not have enough temperature to achieve the required melting state

3. Blow molding cycle is too short

4. Mold temperature is too low

5. The exhaust of the mold is insufficient, and the product cannot be completely attached to the surface of the mold

6. The surface of the mold is dirty and rough

7. The raw materials are too wet, the production process has poor liquidity, and the product surface is not completely evenly distributed

IV  The product surface has spray grain, molten state of raw materials into the front mold, blow molding product surface formed snake grain

1. The temperature of the cartridge is set incorrectly. The temperature is too high or too low

2. The nozzle of the blow molding machine is too small

3. The material temperature at the nozzle is not enough

4. Mold temperature is too low

5. The ejection speed is too fast, leaving no time for the molding process

6. The water outlet is in the wrong position

7. The nozzle flow channel is too long

8. The quality of raw materials is not good enough to meet the requirements of production

Engineer (1)

V Blow molding products surface with water grain, blow molding process of two streams of material flow can not converge to a place

1. Mold temperature is too low

2. Insufficient clamping pressure causes mold expansion

3. The injection pressure or injection speed is too low

4. The nozzle is too small

5. The water outlet is not in the right position

6. Nozzle joint area is too long

VI  The product has cracking under normal environmental conditions

1. Incorrect blow molding screw design

2. Blow molding cycle is too short

3. Glue condensation in the flow passage

4. The injection pressure is too large, the screw speed or blow molding speed is too fast

5. The melting material temperature at the nozzle is too high

6. Blow molding pressure is too low

7. The raw material is too wet, and the performance is degraded

VII Blow molding products surface delamination, present fish scale

1. The shooting speed is too slow

2. Blow molding filler is not enough

3. Shoot glue, holding pressure time is too short.

4. The barrel glue melting temperature is too low

5. Mold temperature is too low

6. Tapered nozzle corner

7. Mold runner and gate are too large

8. The outlet material is polluted

9. Influence of external material or auxiliary material

10 blow molding material is too wet

VIII The surface of the product is dirty

1. Oil leakage or lubricating oil dripping from the product

2. Improper packaging and transportation, resulting in pollution due to careless operation

3 blow molding material is too wet

4. Excessive release agent is used on the mold surface

5. The workshop environment is terrible.

These are the common surface quality defects of plastic blow molding products and solutions that HUAN MACHINERY would like to share with you. We can know that the quality of plastic blow molding products and most of the quality of raw materials and blow molding machine processing and production process. Therefore, we should choose the raw materials that meet the production standards and the hollow blow molding machine that is reliable in the production process. At the same time, we also need the correct and standardized operation. If you have any need for production equipment of plastic blow molding products or technical problems of blow molding machine production, you can consult our HUAN MACHINERY online at any time to overcome them, or go to the product interface or technical interface of HUAN blow molding machine to understand.


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