Cold top and hot pull are both processing methods for rigid PVC extrusion. There are great differences between the two methods. The following information is hoped to help you：
| Cold Top | Hot pull |
Notion | PVC cold top extrusion is also called internal pressure extrusion method. It is directly cooled and formed on the die head without forming molds. Its production process is to directly enter the water tank from the die head to soak or spray water for cooling, so that the PVC material is quickly cooled from the die outlet to achieve the effect of cooling and forming. | Hot-draw extrusion is the process of PVC material being cooled by a mold or soft PVC being directly cooled by water. |
Difference | No vacuum in production | Production with vacuum |
The finished product is bright and has high gloss | The finished product is matte |
Slow production speed and low efficiency | Fast production speed and high efficiency |
Easy to shape and easy to operate | Difficult to shape, high technical requirements |
Cheap machine price | Expensive machine price |
In addition, their differences also lie in the different extrusion temperatures and pressures.
Cold top extrusion is performed at a lower temperature, generally at a temperature of 130-150℃, with less pressure. This method is suitable for manufacturing thinner PVC products, such as PVC films, PVC cables, etc.
Hot pull extrusion is performed at a higher temperature, generally at a temperature of 150-200℃， with greater pressure. This method is suitable for manufacturing thicker PVC products, such as PVC pipes, PVC sheets, etc.
In general, cold top extrusion is suitable for manufacturing thin PVC products, while hot pull extrusion is suitable for manufacturing thick PVC products. Both methods have their own advantages and disadvantages, and should be selected according to the needs of the product. Whether it is cold top or hot out, we have corresponding PVC compound to cooperate with your production. If you have any questions about PVC granules extrusion, please contact us.
PVC硬质挤出冷顶和热拉的区别:
冷顶和热拉都是硬质PVC挤出的加工方式。两种方式有很大的区别，以下信息希望能帮助到你：
| 冷顶 | 热拉 |
概念 | PVC高钙管冷顶挤压也称为内压挤压法，直接在机头冷却成型，无成型模具。其生产过程是直接从机头模具进入水槽浸泡或喷水冷却，使聚氯乙烯材料从模具出口快速冷却，达到冷却成型的效果 | 热拉挤出是PVC材料通过模具冷却或软PVC直接进水冷却成型 |
区别 | 生产不抽真空 | 生产抽真空 |
成品是亮面，光泽度高 | 成品是哑光 |
生产速度慢，效率低 | 生产速度快，效率高 |
易定型，生产易操作 | 难定型，技术要求高 |
机器价格便宜 | 机器价格贵 |
除此之外，它们的区别还在于挤出温度和压力不同。
冷顶挤出是在较低的温度下进行挤出，一般在50-70摄氏度的温度下进行，压力较小。这种方法适用于制造较薄的PVC制品，如PVC薄膜、PVC申线电缆等。
热拉挤出是在较高的温度下进行挤出，一般在150-200摄氏度的温度下进行，压力较大。这种方法适用于制造较厚的PVC制品，如PVC管道、PVC板材等。
总的来说，冷顶挤出适用于制造薄型PVC制品，而热拉挤出适用于制造厚型PVC制品。两种方法都有各自的优缺点，具体应根据制品的需求来选择