Energy-efficient Petrochemical Polimerization PP powder pelletizing line

Description of Process Characteristics

There are a large number of batch liquid phase bulk polymerization polypropylene production lines in China, referred to as small bulk polypropylene. The scale of production is small, and the production capacity ranges from several thousand tons to tens of thousands of tons. Because of its simple process, low investment in equipment, and quick results, it has developed rapidly.

However, the batch process polypropylene also has the following disadvantages: the production is powder molding, which is limited in the application range, and the antioxidant-free, powder is easily aged during storage. The performance of the product is unstable, and the performance indexes fluctuate greatly. At the same time, the ash content, volatiles and chlorine content are too large. Therefore, small bulk polypropylene is mainly used in low-end products, while the range of products is narrow, mostly is spinning, woven bags, packing belts, and small injection molding products.

Therefore, the above small bulk polypropylene powder needs to be modified and granulated to enhance its various qualities, and can be applied to middle and high-end products and some special materials. The main enhancements are as follows:

1. Before the granulation, the polypropylene powder is not homogenized by stirring, and the anti-oxidant, halogen absorbent and lubricant are added in the process of the granulation to make general-purpose granules, which improves the comprehensive quality, stability and application range of the polypropylene.

2. The granulation line is equipped with a vacuum degassing unit and a melt filter to effectively reduce its volatiles and ash.

3. Add special-purpose additives (such as nucleating agents, UV absorbers, slip agents, etc.) to make special materials to increase the added value of the products.

On the other hand, there is a huge demand for the special materials of homogenized polypropylene, copolymerized polypropylene and polyethylene in China, such as casting film PP, HDPE gas pipeline and low VOC resin etc. Petrochemical enterprises can meet part of the demand by modifying granulations on the basis of general brands.

Process flow of the production line

The GWHS-160/160 reciprocating extruder main unit in assembly: