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Synthetic resin

May 28, 2020

What is synthetic resin [1]

Synthetic resin refers to a resin product obtained by chemical synthesis of simple organic matter or chemical reaction of certain natural products.

Synthetic resin is a kind of synthetic polymer. Under the action of external force, it can be in a plastic flow state, and some properties are similar to natural resins. The most important application of synthetic resins is to make plastics. In order to facilitate processing and improve performance, additives are often added, and sometimes used directly for processing. Synthetic resin is one of the products with the most varieties, the largest output, and the widest range of applications in the petrochemical industry. At present, there are tens of thousands of plastic varieties reported in the world, among which there are more than 300 plastics that have been industrially produced, and more than 60 are commonly used. Industrial and agricultural production and other fields.

Development process of synthetic resin [2]

Although casting production has a history of more than 6,000 years, the application of synthetic resin as a binder is only a matter of nearly 50 to 60 years. Before the 1930s, clay was the only binder used in foundry production and is still widely used today. It was not until 1943 that German J. Cronin invented the use of phenolic resin as a binder to make thin-shelled sand molds, which created a milestone for humans to use synthetic resins. Since then, new casting resin bonding systems have continuously emerged. In the late 1950s, hot-core furan resins appeared. The core box was kept at 200-300 ° C during core making. After the core sand was injected into the core box, the acidic curing agent quickly cured the core and established a mold release strength It takes 10 to 100 seconds. The core is made by the hot core box method, and the dimensional accuracy of the core is relatively high, which is easy to realize mechanization and automation. However, it consumes a lot of energy and emits irritating gas, and the working conditions of workers are poor. In the late 1960s, phenolic urethane resin appeared. The core box was not heated when making the core, and only a few seconds of blowing amine gas could make the type Core curing. This process is superior to the hot box process in terms of energy, environment, production efficiency, etc. China has been researching since the 1980s and production and application in the 1990s. It has developed rapidly at the beginning of this century. So far, it has been used in automobiles, internal combustion engines, tractors It has been widely used in large-scale production; in the mid-1970s, furan resin cured by sulfur dioxide blowing appeared. Although its curing mechanism is different from phenolic urethane resin sand, its characteristics, such as fast curing and high core strength, are different from Phenolic urethane resins are roughly the same; in the late 1970s, self-hardening synthetic resins appeared, such as self-hardening furan resins, self-hardening phenolic urethane resins, and self-hardening basic phenolic resins. Their common feature is that when molding the core, the sand mold will cure and form in the core box or sand box at room temperature. Among them, the self-hardening furan resin has been widely used in the production of cast steel, cast iron and thick colored castings since the 1980s due to its high temperature strength and excellent old sand recycling properties. So far, a complete product supply and process control management system has been formed from tooling design, raw material preparation, modeling core making, combined box pouring, old sand regeneration to casting defect prevention. Now the national furan self-hardening resin sand production line is close to 600 pieces, with an annual output of about 4 million tons of castings.

Suggestions for the development of synthetic resin in China [3]

In view of the structural contradictions and market demand in China's synthetic resin industry, the current structural adjustment of synthetic resin should adhere to the principles of large-scale installation, product serialization, balanced structure, unique technology, and high-quality service. At the same time, pay attention to the development of varieties and brands, especially to increase the proportion of special materials for synthetic resins, to alleviate the double contradiction between insufficient total and structural shortage. Use new technologies to reduce energy and material consumption, reduce production costs and construction investment, and improve competitiveness.

1. Increase technological innovation, pay attention to technical reliability

Increase technological innovation and expand technological investment. It is expected that the new generation of petrochemical technologies will include the following three parties: one is the efficient and cheap production technology of ethylene and propylene; the second is the technology to reduce the production process and shorten the process flow; the third is the natural gas chemical technology. Some of these technologies are being researched and developed, some have been put into pilot testing, and some have begun industrial production. The first issue of adopting new technology to build large-scale projects is to ensure that they are put into operation as scheduled and long-term stable operation. New synthetic resin technology is a breakthrough for China's petrochemical industry to catch up with the world. At present, we should focus on the research and development of the gas-phase method to produce long-chain branched LLDPE technology, and the gas-phase method to produce advanced olefin copolymer LLDPE technology, and at the same time develop the molecular weight bimodal distribution of polymer HPPE technology. Pvc resin should strengthen the development of hard products and vigorously promote the application in the building materials market. The focus of styrene series resins is to improve quality and increase variety. In terms of polyolefin catalysts, it is necessary to have the ability to develop new products and new varieties required by the market. In the next few years, petrochemical products should rely on technological innovation to enhance product competitiveness and improve economic efficiency.

2. Optimize the synthetic resin product program and choose a reasonable entry point

China's petrochemical products are currently facing a severe market situation. The key to increasing the domestic market share is to increase the competitiveness of products, which ultimately depends on the competitive factors such as product quality, variety, and price. Therefore, choosing a construction plan that can form a comparative advantage is the key to success. Polyethylene and polypropylene are the varieties with the largest consumption, the shortest production process, and the fastest technological progress among synthetic resins, and should be given priority in development. In recent years, the investment in large-scale polyethylene and polypropylene equipment has also been greatly reduced. By introducing high-level technology and large-scale, it can make full use of good raw material conditions and form a competitive advantage. Therefore, relying on the existing ethylene production base and constructing large-scale polyethylene and polypropylene installations with the lowest investment should be the first choice.

3. Adjust the variety structure to ease the contradiction between gill production and consumption

Pay attention to adjusting varieties to meet market demand. Polyethylene, polypropylene and polyvinyl chloride, which account for 80% of the five largest synthetic resin consumption, are still the focus of future development. Polystyrene and ABS mainly rely on imports at present, and the contradiction between production and consumption is more prominent. ABS devices such as Jihua and Ningbo Lejin Yuxing should be transformed in various ways, and the Shanghai ABS project should be built to gradually increase polystyrene and ABS in synthetic resin In the proportion. At the same time, combined with the development of the oil refining and ethylene industries, we encourage the use of refinery dry gas to produce ethylbenzene and concentrate dehydrogenation to produce styrene to meet the domestic raw material demand for synthetic resins and rubber.

4. Strengthen the construction of resin information engineering

Reconstructing the synthetic resin industry with modern electronic technology, computer technology, sensor technology and automatic control technology is an effective way to promote the technological progress of the synthetic resin industry and improve the overall competitiveness of the industry. Electronic information technology will be more closely integrated with the synthetic resin industry to upgrade the technical grade of the synthetic resin industry and play a more important role in improving production efficiency, developing new products and improving services.