What are the factors that affect the smooth mold release of products?
The time of product unmold is the non-production time after the billet blown and formed, the shorter the better.However, if the product can not be removed successfully, it not only prolongs the molding cycle, interferes with the normal molding process, but also increases the billet waste.The factors that affect the smooth demoulding of products mainly include the following.
(1) excessive cooling of products.The increase of cooling time, the increase of air pressure and the decrease of wall thickness are beneficial to the forming of products and the decrease of shrinkage.However, the excessive cooling of products not only reduces the production efficiency, but also reduces the shrinkage rate of products, increases the rigidity and makes it difficult to unmold.
(2) error in mold design.In the design of blown mold, due to poor consideration, the design is not reasonable.For example, the mold cavity is not designed with a suitable parting Angle;Die in the handle, insert parts, its slider action is not coordinated;Improper setting of die guide column or improper installation;The surface of mold cavity has burr and rough;The depth or slope of the grooves in the cavity is unreasonable.All of these will make it difficult for products to be unmoulded.
(3) poor adhesion resistance and smoothness of plastics raw materials.These phenomena can be solved by adding mold release agent (external lubricant) and spraying mold release agent in mold cavity.
(4) operating error.When operating workers produce blow molding products, they accidentally hit the surface of the mold due to careless work, such as scratching the surface of the mold cavity with hard metal tools, causing burrs, etc., which can cause difficulties in mold release.