Progress of plastic processing technology abroad i

2005 foreign plastic processing technology progress

extrusion, injection and blow molding are the three basic processing technologies of plastic products. The continuous improvement of the performance requirements of plastic products in the consumer market has promoted the innovation of processing technology. The advanced technologies in the plastic industry of various countries in the world reported by this magazine in 2005 involve many of the latest technologies in extrusion, injection, blow molding, rotational molding, thermoforming, tape casting and related equipment, as well as products such as two-component injection compression molding combined roof skylight, more transparent New DVD packaging box, McDonald's yogurt packaging cup, thixotropic injection molding 3C (camera, computer and) products Many new products that are closely related to people's lives, such as medical plastic instruments processed by biopolymers, roll forming furniture, are specially summarized as annual reports, from which we can understand the latest development trend and technical progress of the world's plastic processing industry

1 extrusion processing

sheet extrusion technology without pre drying rpccobelplast of Italy has a history of processing and producing PS and pet plates/sheets for more than 30 years, and is also one of the top 10 large pet hard sheet manufacturers in Europe, The company purchased the first pet sheet extrusion production line manufactured by Germany's bertorff (bertorff manufactured all the core and key equipment of this three-layer sheet extrusion production line, including co rotating twin-screw extruder, horizontally arranged 3-roll polishing stacker and lamination device. This production line is also applicable to the production of PP sheets), and plans to double the production capacity

according to belstov, this production line is mainly designed to produce spotless sheets, and the product thickness can range from 100 microns to 1.8 mm. Its core equipment is equipped with ze90a co rotating twin-screw extruder with vacuum exhaust technology. During production, this production line directly sends the crushed leftover materials to the extruder through a material processing system and a gravity metering feeding device, without the need for pre drying equipment. The extruder is equipped with a material filtering system and a reverse pulse system for recoil. After the material flows through the melt pipe and feed head, 3 strands of melt are formed to feed the wide slit die head, and then pulled to the horizontal polishing device. The maximum roll gap pressure set on the horizontal polishing device is 1500n/cm, which can be adjusted by the motor during the production process. The obtained sheet also needs to go through the following processes: surface treatment, cooling, and trimming; Thickness measurement; Silicification treatment and lamination, and finally through the full-automatic double rotation winder. The capacity of this set of equipment is 1200kg/h, the maximum width of the sheet is 1500mm, and at the same time, it can be divided into 4 pieces at most

pipe extrusion automatic reducing technology

all pipe manufacturers are very clear about what it means to change product specifications in production, that is, to lose time and cost. This accumulation will lead to considerable downtime. Under the condition that more buyer markets require less loss of orders, how to optimize the problem caused by the change of product specifications has become a challenging problem in the pipe extrusion industry. If it can be solved, it can save a lot of time and money, which means it is more competitive

iNOEX company (iNOEX) launched the automatic reducing system (advantage), which provided a technical solution at the first time. It can obtain equal economic benefits by simply transforming the production line, that is, slightly changing the traditional process. The core of the system is an active sizing sleeve, which can change the pipe diameter and their pressure level while maintaining the original die. The system is applicable to polyolefin pipes with an outer diameter of 32-400mm

instant production can be achieved by some modifications of the production line and installing the automatic reducing system

the four fundamentals of the automatic reducing system (advantage):

(1) the system adopts a modular structure, which can dynamically or automatically change the specification of the pipe through a controller

(2) the "active sizing sleeve" and "active sealing sleeve" in the system composition can replace various adjustable sizing sleeves and traditional sealing sleeves in the traditional process

(3) the system can change the production specification, which requires less time and is more convenient

(4) the system can be easily integrated without considering the model of the extruder. As long as the downstream equipment is minimized, it maximizes the replacement of traditional equipment for different sizes. The installation process is also simple, and the pipe specification can be changed without changing the weld size

the automatic reducing system is composed of a guide cavity with size guide rail, an active sizing sleeve, an active sealing sleeve and a controller. The special point is that; At present, the die head and extrusion die used in the production line can continue to be used. The system does not need to change the weld size when changing the specification of new products, which ensures that the scheme does not need investment in other aspects

the change of the corresponding parameters of the overcurrent multiple protection device, such as the melt volume or traction speed of the extruder, enables the production line to produce the required pipe diameter and wall thickness without changing the extrusion die. This means that a fixed weld size will lead to an increase in the amount of molten material, resulting in an increase or decrease in the diameter of the pipe. Reducing the linear velocity results in the thickening or thinning of the wall thickness. The setting of the weld size is not a real limit. In some cases, the diameter of the new pipe is allowed to be larger than the weld size, and then the extended weld pipe can reach the required size through the additional vacuum in the guide cavity

the best configuration is to equip an ultrasonic thickness measurement system behind the first vacuum box, such as the aurax system of inox company, to record the wall thickness and diameter of the pipe. The sooner the parameters are obtained more or less, the sooner the correction can be carried out to achieve the set quality data and document records

foaming film extrusion

SMS machinery manufacturing company in Vienna recently provided its 70th polystyrene foaming equipment to Italy. An Italian plastic factory uses polystyrene foam film to produce thermoformed food trays on a double machine series foaming extrusion equipment. In SMS, people are committed to seizing more market share in food packaging in which enterprises actively respond to challenges by changing the mode of economic development, adjusting the industrial structure, and committed to industrial upgrading. In addition to extrusion equipment, SMS also provides various special equipment for the production of laminated plastics, films or thermoformed parts

Italian plastic factory produces 1 Mm thick polystyrene foamed plastic, with a mass of 65 kg per cubic meter. The total production capacity of the foaming film equipment is 480 kg per hour. Because the SMS scheme has two extrusion heads in series: in the primary extrusion head called "contracool", polystyrene and related additives are weighed through a five kinds of raw material metering system, so that the above mixture is first plasticized and homogenized, and then a high-pressure metering pump with three nozzles injects gas into the plastic melt, Through a sieve exchanger and a mixing tube, the vaporized melt is pumped into the "hydrocool" secondary extrusion head. After the official introduction of the extrusion head at the beginning of this year, the measurement is homogenized again and cooled first

when the maximum temperature is 110 ° C, the melt is ejected through a circular nozzle with a diameter of 135 mm and expands in the form of a foam film, and then the film slides over an internal cooling fine pressing rod and the lower air cooling ring. Thus, the shrinkage of foam film is accurately controlled and shaped. The longitudinal cutter installed on the fine pressing rod cuts the annular film into two 90 mm wide strip films, which are then rolled into a disk and put into storage

extrusion processing of extra large and ultra long pipes pipelife is an international supplier of plastic pipes. The company has 326 extrusion production lines, 160 injection molding machines and 35 factories in 26 countries. With Germany's reifenhauser providing a new extrusion production line, the company's stadehler plant has produced thermoplastic polyethylene plastic extruded pipes with a diameter of 2 meters

pipelife has been supplying large-diameter pipes for offshore use. The pipes directly enter the Bay from the cooling tank of the extrusion line, plug both ends of the pipes, and then drag them to the destination by boat, as far as Brazil. This mode of transportation has been used for pipes at the stadehler plant for the past 40 years

the new pipes with a diameter of 2 meters are mainly used in sewage drainage systems, wastewater treatment and desalination plants. The company official said, "our goal is very clear, that is to expand a new market that was previously limited by the pipe with the largest diameter of 1.6 meters. The pipe with the diameter of 2 meters can almost transport twice the fluid." He also cited three pipes with a length of 1000 meters and a diameter of 1.6 meters that were provided to a seawater desalination plant in Ashkelon, Israel, not long ago as an example, saying: "if there were pipelines with a diameter of 2 meters at that time, only two pipes would be enough."

it is reported that seawater desalination pipeline is now an important field. In recent years, the cost of seawater desalination processing has fallen sharply, so many such projects have been launched in the Middle East and Mediterranean countries

another business opportunity for pipelife is to transport pipes from the power plant, because the power plant previously refused to use pipes with a diameter of less than 1.6 meters. This kind of large-diameter pipe will replace concrete pipe, steel pipe and glass fiber reinforced plastic pipe. The growth of offshore applications is mainly due to the application of these pipes in seawater desalination and power plants

four years ago, a factory in Larnaca, Cyprus began to use pipelife's HDPE pipes and glass fiber reinforced plastic pipes. Since the operation, the flow of HDPE pipes has not changed, and the maintenance cost has not increased, but the 5cm glass fiber reinforced plastic pipe has led to a reduction in flow and higher maintenance costs

the processing capacity of the new extrusion line of leffenhausel and its 40 ton spiral melt guide mandrel head with a diameter of 2.6 meters is 20 tons/hour, and it can produce pipes with a diameter of 2 meters and a wall thickness of 125mm. According to the company, the geometric size and surface coating of the melting channel are designed according to the raw materials used and the low flow rate

competitor Battenfeld said it could also provide a pipe production line with a diameter of 2 meters and was involved in the above projects. Battenfeld company provided traction equipment for the new production line of staatheller factory, Cincinnati company provided one of the two extruders, iNOEX company provided control and monitoring system, Hammel company's raw material drying equipment, local company's cooling water tank and other mechanical equipment

in the staatheller plant, one of the characteristics of pipe extrusion is to inject nitrogen during pipe forming to maintain a high level of oxidation resistance

pipelife uses conventional raw materials PE80 and PE100. Nordic chemical company was the first to improve the anti sag performance of the wall thickness of large-diameter pipes, which is most beneficial to the pipe with a diameter of 2 meters, and maximizes the consistency between the bottom wall thickness and the top wall thickness of the pipe. Other raw material suppliers such as BP, Solvay, atofina and Bassel have also contributed to improving sag resistance

extrusion of multi-layer and thin-wall medical products

Guill mechanical equipment manufacturing company, located in West Warwick, Rhode Island, USA, recently launched several new extrusion die heads. Among them, the "micro flow card" die head is an ultra small cross screw die head, which should