application

Plastic crate  has the advantages of beautiful quality, light corrosion resistance, high strength, no moisture absorption, sanitary quality, easy cleaning, easy processing and molding, which is conducive to civilized production, easy management, cost and long service life.HDPE crate an replace wooden cases, cartons and other transportation packaging containers, widely used in food, beverage and other industries. It is generally made in two ways.

1. Hot extrusion and cold pressing molding

The main raw materials for making plastic turnover boxes are high density polyethylene, copolymer polypropylene and polyvinyl chloride. Plastic turnover box is produced by hot extrusion and cold pressing method, which has less equipment investment, low energy consumption, simple structure and low technical requirements, but low production efficiency, rough product surface and poor mechanical properties, so it is rarely used in actual production.

The technological process is as follows: resin batching dyeing – “melt extrusion -” storage cylinder insulation – “die casting -” finishing.

2. Injection molding

Plastic turnover box and plastic tray in addition to hot extrusion and cold pressing molding, the most commonly used production method is injection molding, injection molding is also called injection molding or injection molding, its principle and the principle of injection needle and operation method is similar, so some people also called this process injection molding. Injection molding is suitable for all kinds of thermoplastics and some thermosetting plastics. The powder or granular plastic from the hopper of the injection machine into the barrel for heating, so that the plastic melting, flow state and good plasticity, and then in the plunger (or screw) under the push of the nozzle at the front of the barrel into the mold cavity with low temperature, after cooling and opening the mold, plastic products can be obtained.

The process is as follows: feeding – heating plasticization – injection – shaping – demold.

At present, the most used injection molding machine is the horizontal moving screw injection molding machine. Injection molding equipment investment is large, mold structure complex, high processing cost, suitable for large-scale production.