Big Difference in Product Weight of Blow Molding Machine: Causes and Solutions

Home / Big Difference in Product Weight of Blow Molding Machine: Causes and Solutions

Big Difference in Product Weight of Blow Molding Machine: Causes and Solutions

Admin August 10, 2019 2 Comments

Today, let's talk about the reasons and solutions for the large difference in product weight of blow molding machines.

In the process of long-term use of the blow molding machine, it is inevitable that there will be some large or small failures. It is more common that blow molding opportunities have large differences in product weight.

So, what is the reason for the large difference in product weight of the blow molding machine?

Large fluctuations in weight have a lot to do with unstable blanking and uneven wall thickness. The main solutions are as follows:

Blow molding machine is a kind of equipment that makes plastic particles into plastic products through blow molding process. In the process of using the blow molding machine, if there is no feeding at the feeding position, it is necessary to check whether there is any material in the hopper first, and if there is no material, it needs to be fed in time. Or check whether it is in a power failure state, check the operation of the motor of the blow molding machine, if it is in a state of power and load, then this situation may be caused by the parison jammed with the lifting belt, causing the parison to suddenly change; Uneven mixing; Blockage or bridging of the feed section, resulting in unstable extrusion speed.

In response to the above problems, we can start from the following aspects: check and repair the wall thickness control equipment to ensure that the preform is more stable; use suitable material mixing equipment to appropriately extend the material mixing time so that the raw materials are fully mixed; check whether there is blockage at the entrance Or other foreign objects block the inlet; appropriately reduce the inlet temperature to avoid "bridge" phenomenon; check whether the extruder motor is abnormal, whether the motor and gearbox are loose or slippery, to ensure that the screw speed is stable; at the same time, we also need to check the electronic scale regularly, Avoid the fluctuation of the measuring instrument from affecting the quality judgment.


When selecting materials, try to use materials with a wide molecular weight distribution. When designing the mold, try to avoid sharp corners and other vulnerable structures. Set the appropriate temperature and cooling rate during the process setting. In the blow molding production process, even if we operate the production process correctly, the blow molding products produced will always have quality defects with large product weight differences. This is also one of the problems that plague many manufacturers of plastic blow molding products.

Another reason is: inappropriate wall thickness adjustment; inappropriate molding temperature setting; unreasonable selection of raw material grades; unreasonable mold design and other reasons. We can re-adjust the wall thickness of the product to strengthen the control of the force wall thickness. It should be noted that the wall thickness is not as thick as possible, sometimes reducing the wall thickness of some parts to improve the anti-drop performance; reset the molding temperature, too high will cause the raw material to decompose too low and lead to poor plasticization; re-select suitable The raw material grade. The raw material properties of each grade are also different. There is no better raw material, only more suitable raw materials; the method of improving the product structure can solve the problem of large differences in product weight.

By re-adjusting the wall thickness of the product, you can strengthen the wall thickness control of the product, reselect the applicable material grade, improve the mold, and add stiffeners as needed to further improve the pass rate of the product.

The above content is the reason and solution for the large difference in the weight of blow molding machine products.

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