In Mold Labels For Plastic Containers

Selecting the correct injection molding machine, in-mold label machine and mold is crucial.

Injection molding equipment can be powered by electricity or hydraulics. Raw thermoplastic pellets are fed into the machine's hopper and gradually fed into the machine's barrel. The screw rotates, progressively heating and melting the thermoplastic until it becomes molten.

A pre-printed polypropylene label is taken by an in-mold label robotic arm and inserted into the mold. This ensures that the label is properly positioned for integration into the final product.

As the molten plastic reaches the end of the barrel, the gate, which controls the injection of plastic, closes. The screw advances, pulling a predetermined volume of plastic through and building pressure within, readying it for injection. The mold tool's two components are held tightly together under high pressure or clamp pressure.

After most of the plastic is injected, pressure is applied for a specific duration, known as the "holding time." This time is crucial for ensuring proper plastic formation and tool packing. After cooling, the plastic conforms to the mold and bonds with the label.

After holding and cooling, pins or plates expel the pieces from the tool. These parts fall to the machine's bottom, where they are collected on a conveyor belt or in a compartment. The finished product is now a plastic product with a printed label.