There are different types of machines used when producing rotomolded plastics. Those machines perform various tasks with a high level of precision. This article shall discuss the different types of rotational molding equipment you need to produce high-quality rotational molded plastics products. Those machines are;

1. Molding machine

Firstly, you must have a molding machine capable of producing large quantities of identical parts with great speed and precision. Molding machines can be categorized by their output regarding the number of products they can make per hour. For example, there are single-shot machines capable of producing one part per cycle; semi-automatic machines that can produce from 2 to 50 parts per hour; and automatic or robotic machines that can produce parts from 200 to 1,000 or more per hour. In general, the higher the output of the molding machine, the more expensive it is.

2. Clamshell machine

Clamshell machines use a pair of molds clamped together to form one cavity for each part produced. The parts are formed from powdered material fed into the space between the two mold halves. The machine's control system then ejects the part from the mold by opening the mold cavity through an ejector pin that presses the top half of the mold upward against the lower half, causing the bottom half to open. This process is often referred to as "clamping." After the clamshell mold has opened, the molded plastic part is ejected and falls on a conveyor belt.

3. Swing machine

A swing molding machine uses two sets of cooperating mold halves. One set of mold halves is stationary and forms the base of the mold cavity. The other half is movable and closes the cavity around the formed part. The mold halves are closed by means of an eccentric mechanism that rotates one of the halves (the movable one) around an axis that is offset from the axis of rotation of the other half (the stationary one). When the mold halves are closed around the plastic charge, the movable half then moves downward toward the fixed half to compress the plastic against the lower surface of the stationary half. After the compression step, the movable half is raised away from the stationary half to allow ejection of the part. In general, swing molds can produce more parts per hour than clamshells, but they are much more expensive.

4. Shuttle machine

Shuttle molds operate somewhat like a clamshell or swing mold. They also use moving and stationary halves to create a mold cavity. However, instead of two mold halves closing around a plastic charge to form a cavity, only one mold half moves to close the cavity around the charge. The mold half that closes around the charge is mounted on a linear actuator (a "piston-type" mechanism) controlled by an electronic sensor. After the mold half has closed around the charge, the sensor causes the piston to advance (close the cavity) a fixed distance and then retract (open the cavity) a fixed distance to allow ejection of the part. Like swing molds, shuttle molds are more expensive than clamshell or clamshell molds, but they can produce more parts per hour than clamshell or swing molds.

5. Vertical wheel machine

A vertical wheel mold works on similar principles as a clamshell or shuttle mold. Still, instead of using a single mold half to close around a plastic charge, it uses two mold halves that are hinged together at one end and have interlocking teeth (like a gear) at the other end. Each mold half is mounted on a vertical wheel that is independently operable by an electric motor. When the mold halves are closed around the plastic charge, the motors drive the wheels forward (close the cavity) a fixed distance and then backward (open the cavity) a fixed length. After the cavity has been closed, the mold halves openusing an ejector pin that pushes upwardly against the top half of the mold to force the bottom halfopen. After the mold has been opened, the part falls onto a conveyor belt or onto another fixture that supports it until it has cooled enough to be removed.

Conclusion

The five discussed are the essential Plastics Rotomolding machines you need for your plastic molding business. You have to determine whether you want to produce one part or many parts at a time. The clamshell mold is ideal for producing one molded plastic part at a time. The swing mold is the best choice for producing large parts (say, thousands of pieces) in one production run. The shuttle mold is the best choice if you have just begun your plastic molding business and want to produce hundreds or even thousands of pieces of one or more parts in one production run. If you have a small volume of plastic molding needs, then the vertical wheel and the shuttle molds are good choices for producing many plastics in one production run.