What is the difference between injection mold and extrusion mold?

Author: MULAN - Plastic Molding Manufacturer

The difference between injection molds and extrusion molds mainly comes from high-restriction molding and semi-restriction molding. Next, Xingye Xiaobian from Shanghai Injection Molding Factory will introduce the difference between injection mold and extrusion mold: Injection molding - fill the mold with plastic with pressure, and directly inject the dissolved plastic into the mold, suitable for wall thickness above 1MM, various structural products . Blow molding - use wind to heat the plastic into a film, inject it into the embryo body first, and then blow it up with air, which is suitable for bottles with thin walls.

Blister: Heat and soften the plastic plate, put it on the mold to cool and form it, and then process it. It is suitable for products with small batches and simple structures. Injection molding molds are generally used to make thicker products, such as bottle caps, etc., and blowing is used for gas, such as bottles, etc. Injection molding is used for thicker products and relatively lower requirements. Blowing is different because the product is thinner and more transparent , A slight disadvantage is obvious. Therefore, the requirements are higher, and blow molding has certain requirements for the toughness and stretchability of raw materials. The requirements for injection molding are lower. Injection molding is formed in a mold, which is limited by the geometry of the mold and does not require high melt strength.

Although extrusion molding also has geometric limitations of the die, it is not completely solidified after exiting the die. In this free state, sometimes it cannot be formed well due to low melt strength, such as spinning. In addition, after extrusion, it is often accompanied by subsequent processing and molding in a free state, such as thermoforming, hollow blow molding, etc. In these molding processes, there are often different degrees of melt stretching, and if the melt strength is low, it is easy to be broken.

Therefore, injection molding generally does not require high melt strength, extrusion generally requires. For more information about injection molds, please visit the official website of Xingye: http://www.dgxingyesj.com/.