Common surface quality defects and solutions of plastic blow molding products

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

In the blow molding production process, even if we operate the production process correctly, there will always be various quality defects in the blow molded products produced. This is also one of the problems that plague many manufacturers of plastic blow molding products.

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

1. Blow molding raw materials stay in the barrel of the machine or in the flow channel for too long, and the properties of the raw materials change

2. There are other impurities in the blow molding barrel

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

4. The temperature difference between the die mouth of the blow molding machine is large

5. The hydraulic oil inside the die leaks, pollutes the raw materials, and changes the properties of the raw materials

6. The blow molding screw and barrel are severely worn, and the raw materials cannot be melted evenly

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

8. The exhaust of the mold is not good or complete, so that excess air accumulates inside the cavity, causing raw materials to burn

9. There is residual grease or lubricant inside the mold, which is in contact with high-temperature raw materials, causing raw materials to burn

10. The quality of raw materials is too poor and there are many impurities

11. The machine parameter setting is confusing and the temperature setting range is inaccurate

II There are bubbles on the surface of blow molding products

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

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

3. The blow molding production cycle is too short, and the cavity gas cannot be discharged in time and quickly

4. The air pressure parameters required for machine production are set incorrectly

5. Blow molding screw speed is too fast

6. Screw back pressure is too low

7. There are volatile additives in raw materials

III  The surface of blow molding products is dull and the finish is low

1. The actual pressure in the blow molding process 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 form the required molten state

3. Blow molding cycle is too short

4. Mold temperature is too low

5. Insufficient mold exhaust, the product cannot be completely attached to the mold surface

6. The mold surface is dirty and rough

7. The raw material is too wet, the fluidity of the production process is poor, and it is not completely evenly distributed on the surface of the product

IV There are jet lines on the surface of the product. When the molten raw material flows into the front mold, the serpentine pattern formed on the surface of the blow molding product

1. The barrel temperature setting is wrong, 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 injection speed is too fast, leaving no time for the molding process

6. The nozzle position is wrong

7. The nozzle channel is too long

8. The quality of raw materials is poor, not enough to meet the requirements required for production

V There are water lines on the surface of blow molding products, and the two streams of materials cannot be merged into one place during the blow molding process.

1. Mold temperature is too low

2. The mold clamping pressure is insufficient, and the product will bulge

3. Injection pressure or injection speed is too low

4. The nozzle is too small

5. The nozzle position is wrong

6. The junction area of the nozzle is too long

VI The product may crack under normal environmental conditions

1. Incorrect blow molding screw design

2. Blow molding cycle is too short

3. Coagulation of rubber in the runner

4. The injection pressure is too high, the screw speed or blowing speed is too fast

5. The temperature of the molten material 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 The surface of blow molding products is delaminated, showing fish scales

1. The injection speed is too slow

2. Insufficient blow molding filler

3. Injection, pressure holding time is too short.

4. The barrel melt temperature is too low

5. Mold temperature is too low

6. Tapered nozzle corner

7. The mold runner and gate are too large

8. The outlet material is polluted

9. Influence of external materials or auxiliary materials

10. Blow molding material is too wet

VIII The surface of the product is dirty

1. Oil leakage or lubricant dripping products

2. Unreasonable packaging and transportation, careless operation causing pollution

3. Blow molding material is too wet

4. Too much mold release agent is used on the surface of the mold

5. The workshop environment is bad.

The above are the common surface quality defects and solutions of plastic blow molding products that HUAN MACHINERY wants to share with you. We can know that most of the quality problems of plastic blow molding products are related to the quality of raw materials and the processing and production process of blow molding machines. Therefore, we need to choose raw materials that meet production standards and hollow blow molding machines with reliable production processes, as well as correct and standardized operations. If you have the needs of plastic blow molding products production equipment or blow molding machine production technology problems, you can consult us online at any time.