Preform molding is an industry term to describe the pro […]
Preform molding is an industry term to describe the process of producing plastic bottles from a single sheet of cold-pressed plastic. A variety of different machines have been designed to produce this material, but most of them use a similar manufacturing process using a variety of common parts. The most common machine parts include blanking metal, hot air casting chambers, a pressure die and a quality mixing valve.
Cold press casting is one of the most common methods used by companies to make polymers. Cold press casting involves two pieces of metal separated by a shallow molten plastic liquid (usually acetone or Freon). These pieces are forced together using a high-speed rotating drum and then gravity fed into a chute. This is a common method of preform molding macking used in thermal spray gun injection molding machines or thermal roll-to-roll tapered injection molding machines.
Cold air casting chambers are often called vacuum chamber. They work on the same principles as hot chamber injection molding machines. In this case, there is no hot air chamber because the plastic material is contained in a chamber that is completely sealed and isolated from outside influences. This type of preform molding macking is popular in the injection molding industry.
The second machine part, the hot air die, is also known by many names such as centrifugal pressure injection molding machine or hot metal die. This machine part uses an electric motor to rotate at very high speeds. There is a need to increase the pressure so that the die reaches its molten stage more quickly. Because of the force of the electric motor, the speed of the rotating die can reach up to 1500 rpm. This type of preform molding machine is used to manufacture all types of parts for the injection molding process.
The final machine part is the cold chamber preform die where the plastic material is loaded into an enclosed chamber. A cold chamber injection moulding machine comes complete with two containers: a cold chamber with a positive pressure of only 0.1 bar and a cold chamber with a negative pressure of about five bar. The preform is formed inside the chamber through the application of varying amounts of heat. The most commonly seen type of preform molding machine is the cold chamber preform blow moulding machine. This is because it provides a quick service, relatively inexpensive and can be easily maintained.