Blow Molding Machine Products Have Flow Marks: Causes and Solutions

Today, let’s talk about the reasons and solutions for flow marks on blow molding machine products.
The processing speed of blow molding products is fast, and the processing speed of ceramic wood products containers is relatively slow, which is time-consuming and labor-intensive and cannot reach the required accuracy. Moreover, plastic containers are cheap, which can effectively reduce the cost of living.
However, during the blow molding process, flow marks and jet lines are often found in blow molding machine products. The reasons for the flow marks of blow molding machine products are as follows:
1. This is caused by the inability of the two streams to merge into one place during the blow molding process when the raw materials in the molten state flow into the mold.
The reasons for this situation:
①The temperature of the barrel is set incorrectly, which causes the temperature to be too low, the clamping pressure is insufficient, and the product produces mold expansion;
②If the nozzle of the blow molding machine is too small or the temperature of the material at the nozzle is not enough, this will happen;
③If the mold temperature is too low, the injection speed is too fast, and there is no time left for the molding process, this situation will also occur;
④If the nozzle position is wrong, the nozzle flow path is too long, it will also happen;
⑤If the quality of raw materials is poor and is not enough to meet the requirements of production, this situation will also occur;
①We must adjust the processing temperature appropriately;
②Clean the runner system or reduce the spray pressure;
③Measures such as raw material purification and timely cleaning of filter plates and magnetic frames can effectively solve such problems.
④In addition, analyzing the location and characteristics of flow marks, helps us quickly find out the cause of the problem and improve the processing speed of quality defects.

blow molding machine products have flow marks

2. Sometimes, the reason for the flow marks of the blow molding machine product is caused by the wrong design of the blow molding screw
①The blow molding cycle is too short;
②The rubber material in the runner is condensed; the injection pressure is too high, the screw speed or the blow molding speed is too fast;
③The temperature of the melted material at the nozzle is too high; the blowing pressure is too low;
④The raw materials are too humid and the performance is degraded.

3. If the injection pressure is too high; the wall thickness controller is not accurate in tracking the wall thickness; the blank mold and other problems will cause the parison to encounter resistance during extrusion, resulting in flow marks on the surface of the parison.

4. There are flow marks on the surface of blow-molded products, which are related to pressure.
The actual pressure in the blow molding process does not meet the production requirements so that the raw materials are not fully integrated.
①The temperature of the barrel is too low, and the raw material does not have enough temperature to reach the required molten state;
②The blow molding cycle is too short; the mold temperature is too low, resulting in insufficient mold exhaust, and the product cannot fully adhere to the mold surface;
③The mold surface is dirty and rough, the raw materials are too wet, the fluidity of the production process is poor, and the product surface is not completely evenly distributed and so on.
①Appropriately reduce the injection pressure;
②Check the wall thickness controller or reset the wall thickness of the parison to reduce wall thickness fluctuations;
③Solution methods such as cleaning and polishing the mold;
④At the same time, ensure that there are no foreign objects in the mold;
⑤Adjust the gap of the die sleeve or mandrel in time.

5. If there is foreign matter in the storage machine or the head, it will cause flow marks and longitudinal stripes on the surface of the product.
When continuous production for a long time, we need to clean the mold regularly, adjust the gap between the die core rods, and pay attention to safety when using or cleaning the gap between the die core rods to avoid personal injury. If the blow molding machine product has flow marks, it is also one of the key factors affecting product quality.

Yankang Plastics Machinery has an after-sales service team. Under the guiding ideology of no worries after customers purchase machines, Yankang after-sales personnel are active in the customer’s production line all year round. The after-sales service of the equipment is not only about after-sales installation, debugging, training and maintenance. At the same time, we conduct return visits and follow-up inspections to old customers and pass more equipment use knowledge and maintenance common sense to customers, which shortens the distance between the company and customers, and wins more and more customers’ recognition.

The above content is the reason and solution for the flow mark of the blow molding machine product.

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