Please discuss the granulation issues of polyethylene and polypropylene in domestic coal-to-olefins companies
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This post was last edited by jordan569 on 2013-1-6 at 20:14. Currently, PE and PP extrusion granulators in the petrochemical industry are the only products that have not been manufactured domestically; moreover, these devices are key components in production lines, and high technical standards are required, especially regarding the granulation molds and rollers. In the petrochemical industry, there are production lines with an annual output of less than 100,000 tons. In China’s coal-to-olefins industry, the capacity of production lines for products such as polyethylene and polypropylene is generally above 300,000 tons, and it is very difficult to produce granulators capable of handling such capacities in China. Regarding the localization of granulation templates, efforts are underway in China, with them being widely used in applications below 100,000 tons. For capacities over 100,000 tons, it is still in the experimental stage in China. Domestic companies mainly use imported templates. Currently, the imported products in use include JSW and KOBEL from Japan, WP from Germany; templates from KENNAMATAL in the United States are also set to enter the Chinese market. It can be said that each of them has its own advantages. I hope everyone will participate actively, and I wish that we **can resolve this issue soon**. Achieve large-scale production using our own extrusion granulators. This post was last edited by li*ngya on 2009-3-11 11:33. Note: # ) # # , .
? ? I study polymers; granulation isn’t that difficult – just add a couple more production lines and that’s it. The synthesis method of polyethylene and polypropylene is closely related to their product forms.
The most costly component in a granulator is the granulation die; the cost of such a die is generally around 1.5 to 2 million, and it needs to be replaced every year or so. When production volume is low, the impact isn’t significant, but in large petrochemical companies, wear and tear on these dies becomes quite noticeable. Moreover, when such companies shut down their granulators for maintenance, it results in several days of lost production capacity. Therefore, resolving this issue is of great importance.
It’s not as difficult as you say. Templates are important, but they don’t wear out that quickly; generally, three to four need to be replaced over a period of ten years.
A production line in Fushun has an annual output of around 70,000 tons; it hasn’t had its molds replaced since 2006, and that’s also quite normal. However, when production volume increases and the load grows, the time decreases. This is also an issue that is being addressed in China at present, but it is still only in the experimental stage. If the same materials are used on a production line with a capacity of 300,000 tons, the time will be different. It is estimated that in the later stages, factors such as the porosity will change, affecting the particle shape. This post was last edited by li*ngya on 2009-3-18 16:51]
I talked with several equipment manufacturers abroad some time ago. This is mainly a material issue. The wear resistance, width, pressure, and other characteristics of the outer roller in roller granulators mean that domestic equipment simply cannot compete with foreign equipment in these aspects.
I also study polymers. Once you work in a chemical plant, you’ll realize that it’s not as simple as you might think. What you’re most likely to see are those small screws used in laboratories, as well as machines that don’t involve granulation; these are not on the same scale as the large-scale equipment used in polymerization plants. In fact, extrusion granulation represents a bottleneck in plastic production capacity, and the downtime of new installations is quite high.
What was said upstairs makes sense. The development of large-scale extrusion granulation units is indeed still in its initial stages in terms of domestic production. At present, Dalian Rubber and Plastic Machinery Co., Ltd. is working hard to achieve this goal. However, for capacities over 300,000 tons, foreign Kennametal equipment is still required; for capacities below 200,000 tons, domestic equipment can be used
As far as I know, Maoming Petrochemical is already using more than 300,000 tons of domestic formwork; those who are interested can go and ask about it
Here we use 30wt material. The plant has been in operation for 2 years now, and the templates have been replaced once. This was mainly due to improper handling at the beginning of operation; spare parts were replaced in order to get the plant up and running as soon as possible. As for that one, after it’s processed, it’s kept in the warehouse (ready for use). As for wear and damage, it’s not that serious. (Said by the experienced granulation expert).
Granulation technology is actually quite rare. If one sets up a polymerization line with several small extruders, the first problem that arises is the need for additional auxiliary facilities, such as hot oil, water for pelletizing, and silos – these requirements increase significantly! A follow-up question: For the same batch of material, during the granulation stage, which machine can guarantee that the particles produced will be identical? So using multiple wires not only incurs higher costs but also brings many subsequent problems!
Hello, I work at the polyethylene extruder position in Pucheng, Shaanxi. My QQ number is 1103494544. Could you tell me your QQ number?