Plastic blow molded product cooling time is an important factor influencing the plastic blow molding manufacturing process. Today, Yankang will bring a question that everyone often asks, that is, how long does the plastic blow-molded product cooling time?
The plastic blow-molded product cooling time is usually longer. It is generally based on the molding cycle of plastic blow-molded products, accounting for one third to two-thirds of the entire molding cycle.
Why Long Time?
Because the production of blow-molded products uses plastic raw materials, the heated plastic may recover elasticity due to the lack of cooling time, resulting in an unstable plastic blow molded products and deformation.
The value given by Yankang here is only an approximate value. The specific cooling time depends on the blow-molded product characteristics, including the raw material performance, the product’s shape, the product’s thickness, and the surface patterns of the products.
The raw material for the blow molding process is different, the plastic blow-molded product cooling time is different. Some raw materials may be cooled longer, while others need to be shorter.
Take polyethylene (PE) as an example. Under the same production conditions and parameters, the cooling time of polyethylene is longer than that of polypropylene.
The more complicated the shape of the plastic blown product, the thicker the wall thickness, the more the number of layers, the larger the volume, the longer the cooling time required.
Everyone should know that controlling the plastic blow-molded cooling time is important, but why is it important, do you know?
This is the case, everyone needs to know that in the process of extrusion blow molding, the expansion of the plastic parison and the cooling of the plastic blow-molded product is almost completed at the same time. Although there will be a deflation time in the process, this time is very short and can be neglected.
Therefore, the inflation time of the parison is similar to the cooling time in a certain sense. The length of the cooling time of the plastic blow molded products and whether it is appropriate will directly affect the quality of the plastic blow-molded products.
If the plastic blow-molded products cooling time is not well controlled or the cooling is uneven, the blow-molded products may undergo deformation, poor surface quality, uneven wall thickness, and other quality problems.
Therefore, it is very important to control the plastic blow-molded product cooling time. In addition to the control of the cooling time, the entire cooling process of blow molding requires special attention. You can refer to the Note On Cooling of Blow Molding. For more questions about plastic blow molding, please continue to follow Yankang. Yankang prepares a Plastic Blow Molded Products Manufacturing Process Video for you.