What is the Difference Between Dowell Casting’s Bakelite Injection Molding Machines and Plastic Injection Molding Machines?

Many injection molding manufacturers nowadays primarily use both bakelite injection molding machines and plastic injection molding machines. Dowell Casting's bakelite injection molding machines are distinct from plastic injection molding machines in several ways. Bakelite, also known as PF (phenolic resin), was one of the earliest industrialized plastics, with its mass production beginning in the United States in 1910. So, what exactly are the differences?

The primary raw materials for producing bakelite are phenol and aldehyde, commonly using phenol and formaldehyde, which undergo a condensation reaction under the catalytic action of acids or bases to produce bakelite. Industrially, there are mainly two methods for production: dry and wet processes.

Under different catalysts, phenol and aldehyde can produce two types of PF: thermoplastic PF and thermosetting PF. The former requires the addition of a curing agent and heat to solidify into a three-dimensional structure, while the latter only needs heating to achieve this structure without a curing agent.

Both thermoplastic PF and thermosetting PF must undergo curing to form a three-dimensional network for practical use. The curing process continues the condensation reaction and results in the final product, a process that is irreversible, involving both physical and chemical changes, unlike the melting and solidification of general thermoplastics.

PF can be injection-molded using methods similar to those used for thermoplastics. The PF used for injection molding requires good fluidity, the ability to mold under lower pressures, high thermal rigidity, rapid hardening, good surface gloss of the molded parts, easy demolding, and non-contamination of the molds, etc. However, injection molding has its drawbacks, such as limitations on filler types within the melt, unsuitability for molding parts with many inserts, and the inability to recycle the large amount of runners and gates after curing, which can only be discarded.

In short, thermoplastic PF can be produced on standard injection molding machines but requires strict control of processing conditions. Thermosetting PF must be produced on specialized PF injection molding machines (with barrels and screws different from standard ones), and the molds must also use specialized design structures!