Blow molding is a commonly used method for the manufacture of hollow thermoplastic products. The main products are cylindrical membrane and hollow container. Blow molding machine can by heating the preform product plasticizing, and then into the mold blow molding, this method is mainly used for high speed and high yield of PET bottles and BOPP bottle production, namely two-step process; blow molding can also and injection molding process are combined into one injection stretch blow moulding machine of an organic whole, which is the production methods of PET containers; blow molding process and extrusion process combined, extrusion blow molding equipment, adapt to a wider range of can production products are more abundant, including multilayer composite films and all kings of polyolefin hollow container, widely used in food, pharmaceutical and cosmetics industries.
Hollow container forming machine
One - step and two - step blow molding process, mainly used for PET and BOPP hollow container molding. Both have their own characteristics, are widely used. The two step method is more suitable for the production mode of the bottle factory which is concentrated on the production of the bottle blank and the dispersed blowing bottle, and one step device is more suitable for the on-line production of the beverage enterprise. Therefore, the current Chinese two-step primary user device is like Zijiang and Zhongfu such professional pet bottle production plant, and one-step equipment mainly Kangshifu, Wahaha such beverage production enterprises.
PET bottle blowing machine is divided into two kinds of rotary and straight lines according to the conveying mode of the bottle blank. Rotary bottle blowing machine production capacity is high, the speed is fast, the design is complex, the price is also high. The typical rotary blow molding machine is France Sidel of SBO series, its type sbo24 blow bottle machine per hour production reached more than 20000 bottles, at present China's tech long also successfully developed rotary bottle blowing machines, production rate reached per hour more than 8000 bottles; straight blow bottle machine typical is the Japanese ASB and Aoki, generally speaking, the mechanical design is relatively simple, but production will become a bottleneck, it is difficult to exceed the 6000 bottles / hour. Hongkong ring Bao group Dongguan Hong Jia Machinery Factory developed BOPP bottle blowing machine, but also the use of linear design.
Temperature control is directly related to the uniformity of the plastic, which is the key to the success or failure of blow molding products. Mold and hot runner design and precision, but also determine the merits of the product quality.
At present, China for PET bottle production of injection stretch blow moulding equipment is basically dominated by imported products, especially in high speed and a large volume of products production, domestic equipment can't compete. It is worth mentioning that, at present, the production of large capacity PET hot filling bottle blowing machine manufacturers rarely, it seems that only ASB repeatedly blowing process to obtain a satisfactory effect.
With the rise of cold aseptic filling process, a new round of the bottle blowing machine market competition will be opened. The SIPA one step blow bottle machine has been in the Beijing Huiyuan Juice Factory gain a firm foothold, but it does not mean that the two-step bottle blowing machines will have no chance.
Extrusion blow hollow container production equipment for material adaptability is stronger, can produce PE, PS, PVC, PC and other materials of the container, product application areas are also more widely. 3/4 blow molding products on the market are manufactured by extrusion blow molding process. Extrusion blow method can produce a few milliliters of eye bottle, can also be processed more than 1000L the tray or tons of barrels.
At present, China's extrusion blowing hollow container production equipment has been fully able to meet the needs of. For example, Akei extrusion blow molding equipment, has formed a series of equipment, production of 200L the following specifications of blow molded containers, and the development of the in mold labeling extrusion blow molding machine. The products are widely used in cosmetics and lubrication oil field. And as the Shantou Jinming Plastic Equipment Co., Ltd and Shaanxi Qinchuan development of a large volume of blow molding equipment has occupied most of the domestic market.
However, the Chinese development of extrusion blow molding equipment from the function is still not perfect, especially some can't production equipment with multi functions, such as widely used for liquid medicine packaging bottle, filling, sealing equipment.
Multilayer composite film production equipment
Blowing process of production of plastic film blowing process is another major product. The developed countries about 40% of plastic packaging film is to use a method for the production of multi-layer co extruded film extrusion blow, the proportion of China's slightly lower. Previous Chinese composite film production the monolayer film of dry or wet composite technology, but the product because the quality is not stable, use adhesive hygiene is poor, high cost, thus gradually be multilayer co extrusion film replaced.
Multi-layer co extrusion composite technology is using multiple extruder in the melt state through special die extrusion forming a new type of functional films, just using a process can be made into a multilayer, multifunctional composite films, as compared to other composite process can save about 30% of production costs. This film can be configured in accordance with the user's requirements of different components, to achieve different barrier requirements and cost requirements.
Before the 1990s, more in China is using the rotary die head production 2 to 3 layer coextruded films, but with the development, three layers of packaging film gradually let in layer 5 or 7 layer film. With this process and catalyze this process is the development of domestic multilayer blown film line. At present, China has emerged a group to Shantou Jinming Plastic Equipment Co., Ltd., Kunshan letter machinery equipment on behalf of the manufacturer to layer 3, 5, 7 and 9 layer coextruded film production equipment production.
Multilayer coextrusion blow film production equipment has a number of key technologies, the die head is one of the most important one. The addition type die head is the most commonly used die head, has the advantages of short flow passage, any combination of layers, temperature control and so on. This mode of production has been the formation of a number of famous professional manufacturers, whether imported or domestic production equipment, most of the need to introduce the die.
The introduction of key technologies and components, is the development of China's blow molding enterprise shortcut. Shantou Jin Ming through cooperation with the German company Eli Finn Ho Sh, the introduction of advanced technology and components, so that product quality has been greatly improved, in the domestic market occupies an important position. As they developed the five layer coextrusion blowing water cooling film blowing unit, using multi-layer coextrusion plane streamline die (SCD die, chit chat (flash) and cold rolling thin film traction high patent technology, applicable in a variety of raw materials processing of PP, PA and EVOH, mLLDPE, LLDPE, LDPE can barrier film producing symmetrical structure, and can produce asymmetric structure resistance diaphragm.
Although the domestic equipment in terms of product accuracy and reliability compared with the import equipment, there are still shortcomings, but its price advantage is unmatched by the import production line. It is by high cost, domestic plastic processing machinery to occupy most of the domestic market, and it is possible to rely on this advantage to enter the international market.
