China 's rubber injection industry technology development bottlenecks and sudden
With the development of rubber industry, rubber molding technology has also experienced different stages of development: molding stage, injection phase, injection phase and injection on the basis of injection molding, injection injection and so on.
Injection molding has become the mainstream of rubber processing
On the characteristics of the rubber itself, injection molding with its unique advantages has now become the mainstream of rubber products molding. Injection process is through the plasticization of the cylinder heating and plastic screw stirring, cutting, the compound temperature to its best fluidity, and then through a higher injection pressure, the state of the compound injection To the mold (vacuum) of the cavity, the pressure and heating, the rubber vulcanization. Throughout the process, the three factors of time, pressure and temperature determine the efficiency and quality of production.
First, injection molding can improve product quality. By the first injection of the mold and the holding pressure, can continue to stabilize the product required to transfer the pressure required to make the product can be controlled under pressure, temperature and time under the vulcanization. Injection molding can improve the compactness and functionality of the product (especially the damping product functionality).
Second, injection molding can significantly increase production efficiency. Through the injection unit of plasticizing function, a substantial increase in the fluidity of the compound, so that it is relatively high temperature filled cavity and immediately began to vulcanization, through a reasonable parameter set, the injection process can reduce the molding process 30 to 50% time.
Again, the injection molding process can significantly reduce the labor intensity, reduce the waste of rubber and power consumption.
Injection molding status and development bottleneck
Compared with the development of foreign rubber injection molding situation, the domestic rubber injection technology is still in its infancy, although the injection molding machine can be used to produce products, but the relevant process research work. A typical example is that most of the production process does not set the holding pressure, but by injection pressure to fill the cavity, which led to the easy flow in the "pie", in the production of flash products and so on.
The development of rubber injection molding can not be separated from the equipment factory, mold suppliers, products factory tripartite cooperation, and jointly promote the application of injection molding and development. But now in the country, these three links are basically independent of their own, the lack of integration.
From the injection molding machine itself, the current domestic market capacity of about 450 million yuan, the annual growth rate of about 30 to 40%. At present, the Chinese market has a large and small 20 rubber injection machine "brand", mostly from the initial Taiwan machine or continental machine evolved. Usually the injection machine manufacturers to find an investor, copy a company's drawings or on this basis to do some minor changes in manufacturing, the use of low-cost or rely on equipment procurement personnel personal relationship, market competition, lack of innovation and research and development capabilities, Which led to the lack of technological innovation equipment, let alone study the rubber injection process.
Domestic rubber injection machine technology more common problems are mainly reflected in several aspects:
First, most of the lower 21 / 22MPa system pressure, nominal 300 tons of models, the actual can only provide 2600KN clamping force, clamping force is insufficient; the corresponding pump, valves are relatively cheap in Japan or Taiwan and other brands, easy to leak and damage, the service life is not long; hydraulic piping, etc. also use split valves, tubes, etc., prone to failure and maintenance difficulties.
Second, the fuselage structure design is unreasonable, open mold space is insufficient, the mold must be removed after the external mold; guide column design is unreasonable, lock nut easy to loose, and thus lead to hot plate imbalance, likely to cause flash and "Pie" and so on.
Three is backward behind the injection unit, each mold need to first shoot about 20 ~ 30g of the compound, and the plastic cylinder temperature is low; clean and replace the compound is very cumbersome, need to disassemble and so on.
The actual use of many machines, the most fatal weakness is instability, often there will be a variety of problems, affecting customer use and production.
In addition, the relevant supporting mold and cold runner capacity is insufficient, mainly in the mold structure and concept of the original, processing and manufacturing accuracy is not high and surface treatment is unreasonable or simply do not do so.
The lack of professional rubber mold manufacturers, most of them are professional to do plastic mold, piggybacked to do some rubber mold, rubber mold understanding and research is not enough, the lack of innovation. China has always been a concept that is simple rubber mold, it is easy, the price is low, in fact it is the concept of this wrong shackles of the domestic rubber injection molding process development and growth.
In addition, the lack of professional injection molding process talent, product factory is also true. At present, the domestic products factory seriously lacks the relevant research personnel, from a foreign-funded enterprises monthly salary of 12,000 yuan recruitment process engineers can find clues. In foreign countries, the process of the factory can make a clear request for machines and molds, and according to the machine capacity and mold to adjust and modify the process, but the domestic capacity of this technology is extremely short, most of the craftsmen only know that Temperature, pressure and time of the three elements, but the injection molding process research and deep understanding is not enough.
Characteristics of new rubber injection machine
In recent years, domestic rubber injection machine suppliers have begun to actively explore, have introduced a new rubber injection machine to meet the needs of the market. Fighter company CHINAPLAS2011 exhibition in the first launch of the servo hydraulic drive system, the industry's praise.
The fighter rubber injection machine uses the European synchronous injection molding technology, in the mold unit structure, injection unit structure and related electronic control system and function, the revolutionary innovation and research and development. In the fuselage structure, the use of a solid and highly redundant design, to ensure that the body strength and durability; high open mold space, the mold can be removed without the need to release and stripping operation.
The hydraulic system uses a Rexroth 25Mpa variable pump (up to 40% energy saving) and a full range of Rexroth valves, which are connected via an integral valve plate and a Parker high pressure line to ensure adequate clamping capability and high reliability. At the same time, the use of first-in first-out injection unit to maximize the plasticization temperature, shorten the curing time, improve production efficiency, and no need to mold out the material head.
In addition, the initial design took into account the injection unit cleaning and maintenance problems, so the production process more humane and easier to operate.