Application of water ring vacuum pump in plastic absorption molding equipment. Degassing, drying, transfer – vacuum technology can be applied to a variety of procedures in the plastic industry.
1. Degassing of extruder
In the process of processing, thermoplastics are melted in the extruder and degassed in the screw part of the extruder. A vacuum device is used to extract gas and steam components from the melt. Extract all low molecular substances to obtain the most ideal thermoplastic quality, with smooth shape, higher strength, better insulation performance and lower gas generation rate.
2. Setting platform (section)
A continuous section of plastic material melted and degassed in an extruder into a set table. Typically, these sections are in tubes, or in various technical sections of windows, trunking, medical tubes, etc. The plastic material is drawn into the mold. For cooling and lubrication, a water film is formed between the inner side of the mold and the continuous working parts, and the air is stably evacuated by the vacuum pump.
3. EPS foaming
In the production of EPS parts and modules, the pre expanded polystyrene drops are blown into the mold by side ditch fan, and then pressurized by steam. Finally, it was polymerized and “roasted” into molded products. In order to avoid distortion during this process – for large pieces, it’s easy to use 3 to 4 minutes – the parts must be cooled. A vacuum device is used for these parts to ensure that they do not deform and that the moisture in them evaporates quickly. The heat generated in the evaporation process is excluded from the work piece, accelerating the cooling process.
A pneumatic conveyor (see below) is used to transfer the spherical material to the dryer before it enters the extruder for further processing. The dryer is a closed system with hot air circulation. The air in the dryer absorbs moisture from the spherical material and exhausts it through the desiccant. The desiccant itself must be blown by hot air so that it can be reused.
5. Pneumatic conveyor
At different stages of production, the plastic ball material must be transferred from one location to another (e.g. from the storage tank to the dryer). It can be realized automatically by using pneumatic conveying device and can speed up the speed. The pipeline is arranged from the start point to the end point and connected to the vacuum pump or compressor.
Because of the material being transported, the air in the pipes is “loaded” – which can stir up leaves, or have the strength of a typhoon, or even lift the roof off the house, depending on the wind speed, compared with a hurricane. According to the weight of the goods and the length of the pipeline, the design of the system can make the vacuum pump (vacuum transfer) or the compressor (pressure transfer) generate enough wind speed to pick up the materials and transfer them to the destination without leaving them in the pipeline.
Due to the large amount of dust generated by the pneumatic conveying device used to transfer plastic ball materials, we recommend the use of filtration system.
6. Vinyl chloride gas extraction and compression
In the process of PVC production, vinyl chloride gas is polymerized under the pressure of automatic autoclave to form polymerized PVC. At the same time, the gas produced is extracted, compressed and liquefied.
The above is EVP water ring vacuum pump manufacturing summary of the application of water ring vacuum pump in plastic absorption molding equipment, hope to help you.