Application of three layer blow molding technology on 200L drum - Deman Machinery

Application of three layer blow molding technology on 200L drum - Deman Machinery

According to the size of the volume of hollow blown plastic products to distinguish: generally 15 liters below called miniature, 20-50 liters called small, 100-160 liters for medium plastic barrels, and more than 200 liters can be collectively referred to as large hollow containers. If according to the sealing diameter and divided into two kinds of small mouth and wide mouth: in practical application, generally 30 liters as the boundary, 30 liters below the small caliber barrels commonly known as closed barrels, the use of barrel external thread + inner cover + outer cover in the form of sealing, used for dangerous liquid packaging; 30-160 liter capacity of plastic drums for the wide mouth commonly known as open bucket, the barrel mouth raised sealing rib + rubber seal + outer cover tight.
Comprehensive analysis of the above classification of hollow blow drums: it can be said that more than 200 liters of plastic packaging containers in large dose of dangerous liquid packaging containers of the highest technical content, the lowest filling and transportation costs, the most widely used category of products.

Now let's discuss the advantages and disadvantages of all kinds of plastic packaging containers with 200 liters and their development direction. At present, relatively mature products on the market mainly include the following categories:    

1:200 Liter double "L" ring low surface barrel and its economical 200 liter single "L" ring plastic bucket.  

200 liter double "L" ring low side drum, referred to as 200 liter double ring drum or 200 liter conventional plastic drum. Because of its overall design, the upper and lower two bottom surface and the barrel body formed into a whole L-shaped convex ring, and because the height of the barrel surface is lower than the barrel mouth and the upper "L" ring named. This kind of packing bucket can meet the United Nations UN standards for class I dangerous liquid packaging requirements, he not only has a reasonable structure design, the characteristics of the barrel body strong, and can be like the steel bucket lifting (or forklift), stacking, rolling, storage and stacking, so it is the domestic and foreign large liquid dangerous goods packaging container in the most widely used, the most convenient class of products. 200L double "L" plastic drum is a kind of packaging container developed with the growth of polymer resin materials in the chemical packaging industry. It is made of high density polyethylene (HMWHDPE) with an average molecular weight of about 300,000, blown by a large extrusion blow molding hollow molding machine. It can be used for acid, alkali, lipid and other kinds of liquid (viscous) state corrosive chemical products filling. Because of its excellent corrosion resistance, high strength, several times the turnover of steel drums and easy recovery, and much attention at home and abroad, and because it can fully meet the International Code for the carriage of dangerous Goods by Sea related dangerous goods packaging container requirements, in the transport of dangerous goods is more and more widely used.

In addition to Germany, Taiwan and other foreign brands, China brand Deman machinery is currently the strongest research and development strength, machinery manufacturing capacity of the most refined hollow machine production enterprises. In plastic machinery has a number of patented technology, its mainstream product hollow machine is mainly used for the production of 200L double "L" ring drums, has quite high reliability and production efficiency, the quality of products produced can meet the requirements of all kinds of dangerous goods packaging, relative to the existing various brand products on the market has a higher cost performance, the main hollow blow molding machine research and development and manufacturing, Blow molding machine can be used for a variety of hollow plastic products, including automobile fuel tank, chemical raw material packaging drums, pallets, IBC ton drums, water tanks and so on, in order to challenge the monopoly position of foreign high-end plastic machine manufacturers. We also carry on the technical transformation of mechanical and electrical equipment, plastic raw materials and products trade and import and export business of the above products.

The most obvious mark of 200 liter double "L" ring plastic bucket compared with other forms of plastic bucket is the "L" ring protruding ring formed by the upper and lower bottom surface and the barrel body as a whole, so that it can be hoisted (or forklift), stacked, rolled, stored and stacked like steel bucket. The most difficult to control in the actual production is the two "L" shaped protruding rings, as well as the "R" ring which plays an important role in the interior of the plastic bucket. Because the two "L" rings and the "R" rings inside the barrel are formed by using the opening distance between the upper and lower moulds and the barrel moulds, when the molten plastic tube embryo is pressed and glued by the pressure of compressed air and the thickness of the molten tube embryo itself during the blowing process inside the mould, it is not formed by the tube embryo directly blowing and compression like other parts of the plastic barrel. And in the upper and lower "L" ring forming process due to the molten plastic by compressed air blowing caused by the reduction of surface temperature, natural reduction of the "L" in the middle of the adhesion. Therefore, in order to make up for the defects of this forming method, we add a new structure "R" ring to the inside of the plastic bucket in the mold design, which is used to increase the impact resistance of the upper and lower "L" ring. The forming process of the upper and lower "L" ring and the inner "R" ring of the plastic bucket may also appear the "bubble" defect.    

To sum up, because the double "L" ring plastic drum in the production process of raw materials, mold design and manufacturing, production process and other aspects have high requirements, so on the basis of comprehensive consideration of production costs and liquid packaging and transportation requirements, the market has developed an economic 200 liter single "L" ring products. That is, the "L" ring on the top of the barrel with lifting (or forklifting) and stacking functions is retained, while the "L" ring on the bottom of the barrel is omitted. Although this reduces the stacking performance of some packaging drums and the rigidity of the bottom of the bucket handling, but can save the corresponding raw materials and improve the anti-drop impact performance of plastic drums, reduce the cost of packaging enterprises. In some low corrosion low risk liquid packaging began to have a certain range of applications, but because of its own limitations only accounts for a small part of the market demand.

2. 200 liter double "L" ring high surface drum and its economic 200 liter single "L" ring plastic drum  

If we analyze the structure of the 200L plastic barrel from the perspective of geometry, the 200-liter plastic barrel we see from the front is equivalent to a cylinder with a height of 90cm and a diameter of 60cm. The upper and lower surface of the plastic barrel can be approximately regarded as the upper and lower sections of the cylinder, and the vertical surface of the barrel is regarded as the length of the cylinder. In this way, from the perspective of solid geometry, the upper and lower sides of the plastic barrel at the circumference of the diameter of 60cm and every joint point of the barrel body are an approximate 90° right Angle contact point. Naturally, when we carried out the transverse drop experiment on the plastic bucket, the two approximately 90° right Angle contact points of the upper and lower parts of the plastic bucket naturally became the weak points subject to the greatest impact force. In the actual test, almost 90% of the damage of the plastic bucket occurred at these two points. According to the forming principle of the upper and lower "L" rings described in the previous section of this paper, although we designed the protection of the "R" ring structure at the corner of the barrel, we also made the arc transition protection to the maximum extent in the shape design of the mold, such as: The arc degree at the bottom of the barrel can be extended downward to a relatively large extent to increase the arc transition length at the bottom of the barrel "R" ring, so that the 90° turning point is the largest distance away from the position of the "R" ring, which can better disperse the impact force of the plastic barrel in the lateral fall and increase the fastness; However, due to the limitation of the height of the "L" ring on the barrel face, the height of the barrel face should not exceed the height of the barrel mouth and the upper "L" ring when designing the mold, because too high will hinder the stability of the upper layer of the barrel during upright stacking, and secondly, it is easy to cause the phenomenon of waste water backfilling and contaminate the filling products at the barrel mouth when the water is flooded for a long time. Therefore, the impact strength of the conventional 200 liter plastic barrel face "L" ring is weaker than the bottom of the barrel "L", according to the author's own experience, the damage probability of the barrel face and roughly accounts for about 60-70% of the total test damage amount.

Therefore, based on the above reasons, we have developed -----200 liter double "L" ring high surface plastic drum for the market, which is a derivative of the 200 liter conventional plastic drum. Specifically, the height of the barrel face is raised upward to exceed the height of the "L" ring of the barrel face, so that the arc transition length and Angle at the "L" ring of the barrel face can be greatly increased, and the impact fastness of the plastic barrel in transverse fall can be increased. Although this kind of plastic barrel sacrifices part of the piling performance, it can effectively increase the impact strength of the barrel face.  

Based on the above analysis, it can be seen that the conventional 200 liter double "L" ring plastic bucket has become the most widely used and convenient product among the hollow plastic containers of 200 liter plastic bucket because it takes into account the performance of lifting (or forklifting), stacking, rolling, falling, storage and stacking. However, both his economic type: 200 liters of low surface single "L" ring plastic drums and his derivative type: 200 liters of single and double "L" ring high surface plastic drums cannot be applied on a large scale in the current market due to the inherent defects of their respective structures.
3. 200 liter double layer double "L" ring and single "L" ring composite plastic bucket  

This kind of plastic bucket is specially developed for food grade liquid packaging hollow plastic bucket packaging form. Its shape is almost identical to that of a regular 200-litre drum. The biggest difference between them is that the barrel wall of the plastic bucket all has a composite structure of two layers inside and outside. His outer layer is the protective layer of the coloring masterbatch, which is generally dark (blue) and can resist ultraviolet anti-sunlight aging. The inner layer is a brand new food grade high density polyethylene raw material. No other additives are used in the production process, so as to ensure the purity of the inner contents and safer use, which can meet the requirements of various food grade liquid canning.
At present, among the equipment suppliers in China, Deman Machinery has successfully developed a multi-layer blow molding machine that can meet the above requirements, and has sold a number of equipment to various regions in China, which has achieved a fairly high market evaluation. Two extruders of this equipment adopt high-speed extruders imported from Germany, which has high efficiency and low energy consumption. Two layer continuous co-extrusion die head, spiral runner structure, no weld marks; The machine head adopts electromagnetic induction heating ring, which can save more than 50% energy. Provide circular barrel mouth, core mold, suitable for circular chemical barrel production, oval mouth mold: easy to form, less flying edge, suitable for blow molding tray production.
4. 200 liters three layer double "L" ring and single "L" ring composite plastic bucket    

Deman Machinery gathers a number of scientists, experts and technical personnel at home and abroad to form a high-tech product research and development team. The company's new research and development of multi-layer (three-layer) blow molding equipment has obtained the national patent, the new product development at the beginning of the clear energy saving, environmental protection, high efficiency, stability as the research and development direction. The main innovation in the direction of energy saving is the conversion of AC motor drive system to servo motor drive system, and the conversion of resistance heating system to electromagnetic induction heating system, because these two systems are the main energy sources of hollow blow molding machine. Deman Machinery grasped the key point after successfully upgrading the servo drive system. And overcome the electromagnetic radiation problem of electromagnetic induction heating system in China, the first to get CE certification, so that the electromagnetic induction heating system successfully equipped in extrusion blow molding machine laid a safe foundation.

Deman Machinery has developed the world's first three-layer co-extrusion large scale blow molding machine with the following features:

1) The middle layer of the three-layer hollow container is plastic recycling material, that is, 50%-70% of the material used in the whole product can be recycled plastic with low price, whose price is half or even lower than that of the new material. The inner and outer layers are each made of 15%-25% new material, which not only ensures the quality of the product but also closes the residual pollution source of the recycled material. Greatly save the equipment user's raw material cost;
2) A large number of digested and recycled plastics can save a lot of energy, greatly reduce the environmental pollution caused by recycled materials, in line with the world's low-carbon, environmental protection, resource reuse and other policies, users can enjoy a number of countries, local government departments preferential policies;
3) Deman three-layer blow molding machine uses servo motor drive and electromagnetic induction heating, which can save more than 50% of the energy consumption in the production process.