Development of plastic molding machine for PET bev

Development of PET beverage bottle plastic forming machine

with the development of beverage, beer, alcohol and other industries, PET beverage bottle plastic forming machine in China has a broad application prospect. However, the high-performance PET beverage bottle plastic molding machine on the Chinese market is basically an imported product. Domestic PET beverage bottle plastic forming machine can not keep up with the market demand

<1 "one step" injection, drawing and blowing hollow plastic molding machine

"one step" injection, drawing and blowing hollow plastic molding machine is the main production equipment of PET beverage bottles. The "one-step" injection, drawing and blowing hollow plastic molding machine is an efficient equipment that continuously carries out the processes of injection molding, heating molding, stretching molding, blow molding and demoulding of molded products on the same equipment. The "one-step" injection, pull and blow hollow plastic molding machine can be divided into "three station" injection, pull and blow hollow plastic molding machine represented by Aoki Ku of Japan and "four station" injection, pull and blow hollow plastic molding machine represented by Nissei of Japan. The main difference between "three stations" and "four stations" is that "three stations" is to complete the injection and heating billets in one process, "four stations" is to complete the injection and heating billets in two processes. At present, the waste injection blow molding machines used in China are basically the equipment of Aoki and Nissei of Japan, which is worth pondering by every hollow equipment manufacturer. The injection and blowing hollow plastic molding machine has its own characteristics, which cannot be replaced by other bottle blowing machines. Foreign manufacturers are optimistic about the Chinese market. According to their estimation, the Chinese market needs no less than 800 "one-step" injection, drawing and blowing hollow plastic molding machines in the beverage packaging industry

1.1 overview of the development of China's "one-step" injection, drawing and blowing hollow plastic molding machine at present, "one-step" research and development of injection, drawing and blowing hollow plastic molding machine by China's plastic machinery factory has a history of nearly ten years, following the path of Japan's Aoki solid "three station" and Japan's precision "four station" models. It is understood that China has no less than four plastic machinery factories put into research and development, But so far, no plastic machinery factory has been able to produce the injection, drawing and blowing hollow plastic molding machine that meets the product quality requirements. The quality of the products formed by the two injection, drawing and blowing hollow plastic molding machines displayed at the 6th Asia Pacific International Rubber Industry Exhibition in Shanghai in 2003 cannot meet the quality standards. The plastic machinery factories that were put into development in the early stage basically gave up the development of this project. Now the new injection, drawing and blowing hollow plastic molding machine has made progress in the mechanical mechanism and control of the host, but it is not mature in the mold. To measure the quality standard of the injection, drawing and blowing hollow plastic molding machine, if the mold fails to meet the requirements, the products that meet the quality standard cannot be blown out. Therefore, according to the overall technical level of the injection, drawing and blowing hollow plastic molding machine in China, it is still in the development stage and cannot meet the requirements of commercialization

1.2 analysis of problems in research and development after nearly a decade of research and development, why can't China's injection, drawing and blowing hollow plastic molding machines reach the level of commercialization. Investigating the reasons, the author believes that the main reasons are as follows:

<1.2.1 misunderstanding of development ideas: only focusing on host development, ignoring mold development. The injection and blowing hollow plastic molding machine is a combination of the host and the mold. From the importance of the host and the mold to the whole machine, the host only accounts for 40% of the whole machine, while the mold accounts for 60% of the whole machine. The successful development of the host does not mean the successful development of the whole machine. The successful development of the injection and blowing hollow plastic molding machine can be said to be successful only if the host and the mold are successfully developed together. The key technology of Japanese Aoki solid "three station" and Japanese Japanese precision "four station" models is the mold, and some of our plastic machinery factories did not correctly recognize the relationship between the host and the mold in the process of developing the injection, drawing and blowing hollow plastic molding machine, only paid attention to the development of the host, but did not put the development of the mold in a more important position. This is the main reason for the failure

1.2.2 the technical level of the mold cannot meet the requirements. The mold of the injection, drawing and blowing hollow plastic molding machine is different from the injection molding mold and has its own characteristics. In the mold of the injection blow molding machine, the key is the mold of the injection mold embryo. The material of the mold has special requirements for its performance, with small coefficient of thermal expansion and contraction, high heat transfer efficiency and high heat conductivity. The structure of the mold is in the form of hot runner. Judging from the current mold technology level in China, it is not possible to develop and manufacture molds of injection, drawing and blowing hollow plastic molding machines that meet the quality standards. It is understood that some mold factories do not know which material to use for the molds of injection, drawing and blowing hollow plastic molding machines. How can they develop molds? The lack of investment in mold factories has prevented the development of mold technology. It is understood that. Foreign mold factories that develop and manufacture injection, pull and blow hollow plastic molding machines have their own injection, pull and blow hollow plastic molding machines. The developed molds are tested on the host repeatedly until they meet the requirements. However, there is no domestic mold factory to purchase the injection, pull and blow hollow plastic molding machine as the trial production equipment for developing the mold of the injection, pull and blow hollow plastic molding machine

￠ 1.2.3 the main engine factory and the mold factory lack cooperation ￠ the main engine factory and the mold factory must jointly develop the injection, drawing and blowing hollow plastic molding machine, and each of them bears its own risks. This is the successful experience of developing the injection, drawing and blowing hollow plastic molding machine abroad. For example, Aoki Gu and Nissei have mold factories supporting them, which are required by the main engine factory, developed by the mold factory and then handed over to users. However, some of our main engine manufacturers do not understand the mold of the injection, drawing and blowing hollow plastic molding machine. In order to save the development cost, they make their own mold. As a result, not only the formed products fail to meet the quality standard, but also the image of the main engine is adversely affected

1.3 development direction 1.3.1 mold mold is the focus of the development of injection, drawing and blowing hollow plastic molding machine. The key point of developing the mold of injection, pull and blow molding machine is to develop the mold of injection mold blank. The key point of developing the mold of injection mold blank is the mold material, the design of hot runner nozzle and hot runner, and the temperature control system. At present, in the case that the mold of the injection, drawing and blowing hollow plastic molding machine in our country cannot reach the technical level, the main engine factory can cooperate with relevant foreign mold factories. As long as the mold reaches the application level, coupled with our host, it can be said that IBM researchers have found that graphene material can significantly reduce the cost of blue LED, and the injection, pull and blow hollow plastic molding machine can go to the market

1.3.2 main engine the performance of the main engine has reached the basic performance requirements, but there is a gap with the equipment of Aoki Ku and Nissei Corporation of Japan. The piston and oil cylinder should be exchanged at the consumer factory. The key points of development are:

high speed and positioning stability of rotary table. The operation and positioning performance of the rotary table affect the forming efficiency. The injection and blowing hollow plastic molding machine is a high-speed molding equipment, and the high-speed operation of the rotary table is an indispensable part of high-speed molding. The operation of the rotary table must meet such requirements. Start and rotate at a high speed. At about 100mm from the next station, suddenly slow down and rotate at a slow speed until the positioning point has no back and forth swing, no impact and stable positioning. Judging from the operation of the host machine developed by each factory, the high-speed operation speed of the disc is not enough, and the disc swings back and forth when positioning at the fixed point of each station. It often needs to swing several times before positioning, which affects the production efficiency. The key to solve this problem is to improve the control level and control accuracy of hydraulic and electric gas

1.3.3 blow molding clamping mechanism. The blow molding clamping mechanism of Aoki Corporation of Japan has used the gear rack high-efficiency and high-speed synchronous clamping mechanism. The principle of this clamping mechanism is similar to the gear rack synchronous clamping mechanism of the extrusion and blowing hollow molding machine. This clamping mechanism has high repetition accuracy for neutral energy, but we still use the obsolete inefficient one-way clamping mechanism without automatic centering performance or the clamping mechanism that two templates operate simultaneously under the action of pressure oil, Following the old path of similar machine manufacturers in the world, the running time of the rack and pinion synchronous clamping mechanism is reduced by 30% compared with the one-way clamping mechanism, and the energy consumption is reduced by half compared with the clamping mechanism in which two templates operate simultaneously under the action of pressure oil

1.3.4 high speed, high efficiency, high quality and low energy consumption the main advantages of injection, drawing and blowing hollow plastic molding machine are fast running speed, high efficiency means high running efficiency, high quality means high quality such as precision and transparency of formed products, and low energy consumption means low energy consumption of formed products. High speed, high efficiency, high quality and low energy consumption is the embodiment of the comprehensive technical level of the host and mold, and is the goal of our further efforts. At present, the cycle operation time of China's injection, drawing and blowing hollow plastic molding machine is about 60% slower than that of similar machines in the world, without considering the product quality. When forming 600ml PET bottles with six moulds, the production efficiency is reduced and the energy consumption is increased. The "three stations" do not need to reheat the parison in the blow molding process, so the energy consumption is lower than the "four stations". Japan Aoki solid sbll-50s - mold four cavity three station, the cycle time is only 4S, 8.5s to form four 26.2g bottle mouth diameter of 60mm 0.5L bottles

<2 "one-step and half method" injection, drawing and blowing hollow plastic molding machine

"one-step and half method" molding machine is different from "one-step" injection, drawing and blowing hollow plastic molding machine in that there is a long transition time between parison injection and stretching, that is, the conventional injection parison equipment and one-step Fara blowing hollow molding equipment are combined into a comprehensive injection, drawing and blowing hollow plastic molding machine, which has the advantage of reducing the requirements of the mold, After reheating, stretching and blow molding, the parison is biaxially stretched to improve the orientation crystallinity of PET bottles, so that they can be hot filled at 87 ℃. From the current comprehensive level of research and development in China, the "one-step and half method" injection, drawing and blowing hollow plastic molding machine is suitable for national conditions and has the research and manufacturing capacity from host to mold. The focus of research and development is how to improve productivity

<3 pull blow hollow plastic molding machine

<3.1 development direction of "one-step" pull blow hollow plastic molding machine

<3.1.1 improve the forming speed

the main advantage of "one-step" pull blow hollow plastic molding machine is its fast forming speed. Therefore, improving the forming speed is its main goal. The model of sidler company in France is sbo-24kc. The number of cavities of the stretch blow mold is 48, and the output of forming 0.5lpet bottles reaches 60000/h. The key to improve the forming speed is to optimize the heating system to reduce time, improve the transmission speed of bottle blank operation, improve the performance of fast and stable positioning of bottle blank, and shorten the opening and closing of mold and blow molding compaction