Several Hazards of Excessive Calcium Powder Adulteration in CPE (Chlorinated Polyethylene)
The Introduction of CPE:
Chinese name: chlorinated polyethylene
English name: Chlorinated Polyethylene
Structural formula: [CH2-CHCl-CH2-CH2 ]n
English abbreviation: CPE or CM
Chlorinated polyethylene (CPE) is a saturated polymer material, white powder in appearance, non-toxic and odorless, with excellent weather resistance, ozone resistance, chemical resistance and aging resistance, and good oil resistance, flame retardancy and coloring
Good toughness (flexibility at -30°C), good compatibility with other polymer materials, high decomposition temperature, decomposition to produce HCL, HCL can catalyze the dechlorination reaction of CPE.
Chlorinated polyethylene is a polymer material made from high-density polyethylene (HDPE) through chlorination substitution reaction.
According to different structures and uses, chlorinated polyethylene can be divided into resin-based chlorinated polyethylene (CPE) and elastomer-based chlorinated polyethylene (CM).
In addition to being used alone, thermoplastic resins can also be blended with resins such as polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), polystyrene (PS), ABS, and even polyurethane (PU).
In the rubber industry, CPE can be used as a high-performance, high-quality special rubber, and can also be combined with ethylene propylene rubber (EPR), butyl rubber (IIR), nitrile rubber (NBR), chlorosulfonated polyethylene (CSM), etc.
Other rubbers are blended for use.
Several hazards of excessive calcium powder adulteration in CPE
1. The main users of CPE are profile, pipe and gusset manufacturers.
Although these manufacturers add calcium carbonate to their production, they have different requirements on the type of calcium powder (light calcium, heavy calcium, active calcium, nano calcium), calcium powder density, and calcium powder whiteness. However, the calcium mixed in CPE
Powder is a cheap low-grade calcium carbonate with coarse density, insufficient whiteness and large color difference, which will affect the surface gloss of the product and cause spots and color differences on the surface of the product.
2. At present, the calcium carbonate used by most CPE manufacturers is granular calcium.
Although a considerable amount of calcium powder was mixed in CPE, it was invisible to the naked eye, and no whitish powder was found when it was inserted by hand. The reason was that granular calcium was added to CPE.
Granular calcium is granulated by heavy calcium or light calcium plus 10% stearic acid. Choose the particles close to the calcium carbonate particles and CPE particles, which makes it difficult for human eyes to distinguish.
However, experiments show that compared with ordinary calcium carbonate, granular calcium is not easy to plasticize. For example, irregular white spots will appear on the surface of the pipe during the production of electrical threading pipes. This is the granular calcium that is not shown to be plasticized, and the product’s flexibility is reduced.
The hair is brittle and breaks easily.
3. Whether it is general calcium carbonate or granular calcium, its specific gravity is different from that of CPE. When CPE is adulterated with calcium powder, it is not easy to mix. This results in that even CPE products from the same reactor, CPE packaged first, are drunk.
There is a large gap in the content of CPE calcium powder in the package, and some have no calcium powder close to the pure CPE material. The CPE content of the same batch number is different, which makes it difficult for users to determine the process, resulting in fluctuations in the quality of pipes, profiles, and gussets.
In actual production, some companies have to increase the amount of CPE in order to avoid fluctuations.
4. In CPE products with calcium addition, only CPE molecules play a role in impact modification. CPE is mixed with granular calcium. The factory will increase the cost in the mixing process, packaging process and freight link compared with no calcium. It is different from pipes, profiles, gussets,
It is more expensive for manufacturers to add more qualified calcium carbonate during their own production.
Therefore, if an enterprise wants to use calcium-added CPE, it is better to use pure CPE and add more calcium powder approved by the factory at home.
5. Because of the inclusion of calcium powder in CPE, the market price of CPE is confused, and it is difficult for users to purchase CPE.
Users ask CPE manufacturers to reduce prices, and manufacturers always agree, but they provide CPE.
However, it is different from the previous batch of CPE, and more calcium powder is added, which reduces the cost-effectiveness of the product even more.
There was once a joke on the market that the price of CPE products was requested by users to reduce the price by 300 yuan/ton, and the gross profit of CPE manufacturers increased by 200 yuan/ton due to the addition of calcium powder.
6. Some large-scale private enterprises, because their bosses do not participate in raw material procurement and production management, do not test the content of calcium powder in the incoming CPE. Because of their interests, the quality of some CPEs that are mixed with a lot of calcium powder has been artificially myths.
"It has been claimed that the CPE of a certain enterprise is the best, and the production of our company's products cannot be separated from the CPE of this enterprise." It simply ignores the existence of the CPE national industry standard HG/T2702-2002.
While the pure material CPE is often manipulated during the trial of the company, and then rejected.
Doing so will have an impact on the cost of raw materials, continuous production without failure, and the development of new products, and will eventually lead to a decline in the competitiveness of the company's products.
In short, it is not technically feasible to use CPE that is excessively added with calcium and is cheap, and it is not economically counted. The ancients said: There is no wrong selling but wrong buying.
we recommends that users use pure CPE. The use of pure CPE materials can facilitate the work of procurement personnel and technical personnel, and can avoid misunderstanding and suspicion of procurement personnel and technical personnel. The use of pure CPE materials can ensure stable production and stable product quality; compared with the use of pure CPE materials, it can also save the cost of storage materials and improve the economic benefits of the enterprise.