Princeton Case Company
615 Sherwood Parkway
Mountainside, NJ 07092
(908) 687-1750

Three Types of Blow Molding

Blow molded cases are created by using a process in which air is used to inflate soft plastic into a mold cavity. Blow molding was invented in 1938 but exploded in businesses in the late 90’s. There are three types of blow molding.

Extrusion Blow Molding (EBM) is one type of blow molding. With EBM, you start by melting the plastic and forcing it into a parison. A parison is a hollow tube of plastic to be formed into a hollow object. Once the molten metal is in the parison, the parison is placed in a cool metal mold. Air is blown into the parison so it can inflate to the desired object. After the plastic is cooled, the mold is opened and the object is removed.

Injection Blow Molding (IBM) is the second type of blow molding. IBM features a two-stage process. The parison is produced in a separate operation. The process begins by injecting molten plastic into a heated mold around a hollow mandrel blow tube. After this, a preform-mandrel assembly is placed in a larger mold cavity for blow molding. Then the part is stripped from the core rod at an ejection station. Out of the three blow molding processes, this is the least popular. IBM is typically used to make small medical or single serve bottles.

The last type of blow molding is Stretch Blow Molding (SBM). SBM produces a part with a biaxial molecular alignment. At first, the parison is elongated in a mold and then expanded in a blowing process. The temperature used in this type of blow molding is lower than all other types of blow molding. The low temperature and small temperature range do make this process harder to control.

Related Reading

Home | Plastic Carrying Cases | Blow Molded Cases | Heavy Duty Watertight Cases | Custom Carrying Cases | Custom Foam Inserts | Site Map
Princeton Case Company, Inc.

615 Sherwood Parkway
Mountainside, NJ 07092
(908) 687-1750 * Fax (908) 687-1755