EPDM电线料造粒机-玖德隆机械（昆山）有限公司

Preheating device Cable core preheating is necessary for both insulation extrusion and sheath extrusion. For the insulation layer, especially the thin layer insulation, the existence of pores cannot be allowed. The wire core can be completely removed from the surface moisture and oil by high-temperature preheating before extrusion. For sheath extrusion, its main function is to dry the cable core to prevent the possibility of pores in the sheath due to moisture (or moisture around the cushion layer). Preheating can also prevent the residual internal pressure caused by the sudden cooling of the plastic during extrusion. During the plastic extrusion process, preheating can eliminate the large temperature difference formed when the cold wire enters the high-temperature machine head and contacts the plastic at the die mouth, avoiding fluctuations in the extrusion pressure caused by fluctuations in plastic temperature, thereby stabilizing the extrusion volume and ensuring Extrusion quality. The extrusion unit uses an electric heating wire core preheating device, which requires sufficient capacity and ensures rapid temperature rise, so that the wire core preheating and cable core drying efficiency are high. The preheating temperature is restricted by the pay-off speed and is generally similar to the temperature of the machine head.
Cooling device
The formed plastic extrusion cladding should be cooled and shaped immediately after leaving the machine head, otherwise it will be deformed under the action of gravity. The cooling method usually uses water cooling, and is divided into rapid cooling and slow cooling according to different water temperatures. Rapid cooling is direct cooling with cold water. Rapid cooling is beneficial to the shaping of plastic extruded cladding. However, for crystalline polymers, due to the sudden cooling, internal stress is likely to remain inside the extruded cladding structure, resulting in cracks during use. Generally, plastics The layer adopts rapid cooling. Slow cooling is to reduce the internal stress of the product. Water of different temperatures is placed in the cooling water tank in sections to gradually cool down the product and shape it. The extrusion of the product is carried out by slow cooling, that is, through three sections of hot water, warm water, and cold water. cool down.
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