Wood-plastic composites are mainly used in construction industry (building board) and automobile industry (door panel, back shelf panel, ceiling, overhead box, protective panel, etc. ), warehousing industry (pallets, padding, packing boxes), transportation industry (road noise partition, protective fence, seat partition, rail sleepers), agriculture (scaffolding, tanks, barrels) and facilities (floors, barrels). Taking pallets as an example, the domestic market demand is about 654.38+0 billion, more than 90% of which need to be changed to wood plastic, and a new industry with an output of 654.38+0 billion tons and a value of 60 billion yuan needs to be developed.
However, there are many key technologies in the production of wood-plastic composite products: resin, wood flour manufacturing technology, wood flour drying technology and wood flour interface treatment technology; In injection molding, extrusion and blow molding equipment, single screw or twin screw is required to have good dispersibility, wettability, mixing, shearing, exhaust, dehydration, devolatilization and defoaming functions for wood flour; Plasticized parts should be corrosion-resistant and wear-resistant; The equipment shall have the function of accurately controlling the above process conditions and the residence time of materials in each part.
TPE rapid processing technology
It is predicted that, in the near future, injection molding workers can significantly shorten the processing cycle by adopting new technologies when processing SantopreneTM thermoplastic rubber. This technology can not only greatly reduce the cost of producing a single part, but also improve the processing capacity of injection molding. By combining this advanced processing technology, the new series of SantopreneTM TPE will soon appear with a new look, and its processing speed will be 25% higher than that of the usual SantopreneTM rubber brand. These materials with improved processability can also significantly reduce the production cost of injection molding machines.
It is reported that by putting this latest SantopreneTM rubber technology into the market, it can help processors save production costs, improve production capacity and be more conducive to their business expansion. At the same time, this new rapid processing technology further expands the economic boundary of choosing SantopreneTM rubber instead of thermosetting rubber.
Other advantages of choosing SantopreneTM rubber instead of thermosetting rubber include easy processing, design adaptability, consistency of parts, recyclability and effective utilization of waste materials, including those generated during production and after the service life of parts.
This technology can also be used for injection molding, blow molding and extrusion molding. However, what can benefit most from this new technology is injection molding, a production type that requires a long processing cycle.
New development direction of packaging machinery control technology
The present mechanical control system seems to be single, but it includes logic and motion control system, man-machine interaction system, diagnosis system and even artificial intelligence system. The following examples from packaging machinery manufacturing industry will reveal the new development direction of mechanical control system.
Like most technologies, the development of mechanical control technology has experienced twists and turns. From a simple and huge control system in history to a small multifunctional control system today, it organically combines mechanical, motion control and communication systems.
At first, the first generation of packaging machinery used in the field of packaging was called GEN 1, which had a simple structure and was purely mechanical. The motor drives the linear shaft to rotate and generates electricity through the cam. The control system with programmable controller (PLC) has a simple structure, and the machine is directly controlled by the operator. In most cases, human-computer interaction technology (HMI) has not been adopted. Then the second generation of packaging machinery appeared. This technology was born ten years ago. Packaging machinery is still driven by transmission shaft, but the structure is more complicated. Because the speed is controlled by the servo motor, it can send instructions to some special actions, and it also adopts a more complicated PLC programmable logic controller. Indeed, the second generation packaging machinery has better adjustability, but this advantage requires higher cost. These expenses include more wiring arrangements, more input/output (I/O) equipment of PLC programmable logic controller, huge and complex, more sensors and program control, and even more peripheral equipment; And it is more difficult to remove and deal with the fault.
Author: Bai Jiena replied to this speech on March 27, 200716: 48.
-
2 new plastic processing technology 10
Nowadays, the third generation packaging machinery combines the so-called "mechatronics" concept, and adopts servo system and simple mechanical device to achieve the purpose of performing complex actions. The goals pursued by manufacturers are: cheaper machines, faster working speed, better performance and small floor space, so it is not surprising that new technologies are constantly introduced according to demand.
The third generation packaging machinery was born four years ago, and its development focus shifted to single-box control technology, with logic PLC function and I/O equipment. If necessary, it can also be equipped with HMI technology, even Ethernet and network communication service system to facilitate communication between enterprises. Previously, the second generation packaging machinery needed an encoder and a programmable limit switch (PLS) to determine the servo position. Now, because the third generation packaging machinery has I/O devices, the servo control system exists in a processor. When the servo system is in place, it will generate induction action and send a signal through the bus to start any required process flow.
Two-step granulation of engineering thermoplastics
German Ma Wei Machinery Company showed the latest achievements of two-step granulation equipment and two granulators at Milan Plastic Exhibition on February 6th, 2006. This equipment is suitable for economic granulation of engineering thermoplastics such as ABS, PA, PBT, PC, POM, PPA and LCP. Especially for the granulation of reinforced glass fiber in the form of large waste blocks or large-scale production leftovers.
In two-step granulation, the material to be granulated is pre-granulated into particles of about 40mm in WLK solid single-axis main granulator, and then further granulated into final particles of about 3- 10mm through NZ subsequent secondary granulator, which is specially designed for the secondary granulation of pre-granulated materials.
In order to avoid the failure of granulation, it is necessary to feed the pulverizer continuously and appropriately, but these requirements are difficult to guarantee by manual operation. Once the feeding is excessive, it will usually cause uneven and fluctuating particles, accompanied by high standard noise. In this way, the thermal energy of the accumulated or crushed materials will be weakened by friction. In addition, the high sensitivity to interfering materials and the common high blade wear that leads to frequent blade replacement remain to be seen.
In contrast, two-step granulation can make the main granulator feed discontinuously, in which the hopper plays a buffering role. This feeding method is of great significance to the optimization of the whole production process, because those operators can be busy with other work without continuously operating the granulator.
By controlling the intermittent switch, the pre-granulated particles are now well added to the NZ secondary granulator. The arrangement of two granulators can choose one above the other or one behind the other. The secondary granulator works according to the working principle of the cutting machine and is specially designed for pre-granulating particles. Compared with ordinary granulators, the second-generation granulators are much smaller in size and only need less driving energy. Because of its uniform feeding, the running speed is about 450min- 1, and no fault has occurred. When this granulator is used for the secondary crushing of pre-granulated materials, the noise level produced is much lower than that of one-step processing at the same speed (n=450-500min- 1).
Cortez will show KCC20D extrusion blow molding machine.
Cortese Machinery Manufacturing Co., Ltd., a pioneer in the field of global blow molding machinery manufacturing, will once again participate in the International Rubber & Plastic Exhibition to be held in Shanghai from April 26th to 29th.
In this year's booth (Hall W2, platform E03), Cortez will show a KCC20D extrusion blow molding machine. Equipped with ZWVP30 four-cavity mold, the center distance 100 mm, this machine will produce 0.75 liter round bottles, with an output of 2,400 bottles/hour.
Cortez can provide all kinds of blow molding machines. The die used for producing continuous extrusion or oil storage cylinders is equipped with a movable clamping device or a parison feeding device, and is used for producing packaging containers with a capacity from several milliliters to 30 liters, even large containers with a capacity of 65,438+00,000 liters, and a six-layer or seven-layer extrusion fuel system to produce three-dimensional spiral pipe fittings. This can minimize flash and meet the use requirements of technical components such as automobile pipes and household appliances.
Single Sandwich Injection Molding and Automobile Technology
The automobile industry continues to face the demand for flexibility and the great pressure of continuous improvement of production methods. In addition to cutting costs and meeting the continuous requirements of increasingly stringent environmental regulations (such as emission reduction and second-hand car disposal), there are also safety issues including the five-star European NCAP rating system.
The current trend, for example, there are more and more car models for specific markets, which need to be further developed in terms of platform sharing policy, spare parts sharing system and combination design method. Other hot topics include value-added, functional improvement and vehicle weight reduction.
The plastics industry can now make great contributions to lightweight structure, versatility and design flexibility. Moreover, the process similar to single sandwich, multi-component solution, shortening cycle time and reducing energy consumption all help to reduce the overall cost. Figure 1 only shows how much the reduced material requirements and shorter cycle time, that is, the increased output, affect the production costs related to single-component automobile parts.
Single Sandwich Injection Molding and Automobile
The single sandwich process with different core materials and skin materials has great competitive advantages. The following table summarizes these two processes.
Especially for large parts, the material cost reduction realized by using recycled materials in the core layer can make great contributions to the overall cost saving. At the factory open day held last year, Ferromatik Milacron demonstrated two applications of single-core injection molding to reduce the component cost.
K-TEC 350 MSW machine is equipped with an attached extruder, which represents a typical single-layer sandwich process and is used to produce door inner panels. Before injection molding, recycled materials are introduced into the injection device. Then the recycled material and pure material (used for cortex) are injected into the mold at one time.
A spoiler with integrated central brake light was produced for a French automobile manufacturer on MAXIMA 800 MSW-2F machine. The structure of the machine includes a second injection device, which can be used for single-core injection molding. For this application, the single sandwich process combines the glass reinforced core material with the Class A paintable skin material.
The center console assembly inside the automobile is another field where the single sandwich process brings new production methods. This is a combination of high-quality soft touch surface material (TPE) and core layer with stable size. The single mezzanine process has a high degree of design flexibility here, for example, collecting pens or credit card clips, or maps and paper clips. Center console components like this can be used to avoid unnecessary gaps: this is due to the tolerance of material combination. In addition to these functional advantages, the single sandwich process also has the above-mentioned saving potential, because the trend of choosing core materials which are much cheaper than TPE skin materials has begun.
As these examples show, Ferromatik Milacron's single sandwich technology has brought many things to the automobile industry. Top OEM manufacturers have been using or are implementing the single-layer sandwich process.
Advantages and disadvantages of injection-blowing process
Advantages of injection-blowing process:
1. Plastic bottles are molded once from raw materials to finished products, with high degree of automation, no need for manual secondary processing, labor saving and sanitation, which meets the GMP requirements of medical packaging and is especially suitable for producing medicine bottles.
2. The product has beautiful appearance, accurate bottle mouth size and stable plastic bottle weight.
3. Plastic products are made of injection parisons by blow molding at one time, and there is no waste at the mouth and bottom, and the mouth of the bottle is flat and sealed.
4. Suitable for producing high-grade and exquisite plastic hollow products, such as cosmetic bottles, baby bottles, space cups, light balls, etc.
Compared with the extrusion process, the injection-blowing process has the following disadvantages:
1. The process is complex, and the mold processing is difficult to master.
2. There are many die parts, long production and processing cycle and high cost.
3. Not suitable for multi-variety and small batch products.
Japan has developed plastic ceramic composites.
Recently, Japan has developed a new technology to integrate plastics and ceramics. The method comprises the following steps: firstly, coating a special inorganic material on the plastic surface, and applying a special treatment method, so that the surface structure of the plastic has instantaneous super heat resistance and is easy to be closely combined with ceramics; Then, ceramic particles are sprayed out at a high speed at an ultra-high temperature of 20,000 degrees Celsius by plasma spraying, so that plastic and ceramics are integrally formed. The surface hardness of the composite material made in this way is more than twice that of steel, and it has the advantages of light weight, high strength, impact resistance, good processability and so on, and is widely used.
San Wanti has added a multi-regional product line to expand to small applications.
As one of the world's largest suppliers of hot runner system, mechanical nozzle, temperature controller and sprue sleeve in injection molding industry, Synventive has been recognized by most customers as a large and medium-sized hot runner system supplier mainly for automobile industry. Recently, however, in order to meet the growing demand for small-scale applications, the company has developed four new series of hot nozzles, thus expanding its multi-zone product series; The minimum glue injection amount of the expanded product series can reach 0.1g.
The newly developed four series of hot nozzles include two series of 04 and-brand-new-two series of 03, and their standard injection channel diameters are 4.0 and 3.5 mm respectively. The structure of hot nozzle "wide inside and thin outside" is the key to research and development. In addition to the slender shape, the maximum length is 186mm, the ideal diameter range of injection pipe for 04 series is 2.5 to 6.0mm, and that for 03 series is 2.0 to 4.5 mm. The key to realize the effective relationship between the inner diameter and the outer diameter of the hot nozzle is to use compact and interchangeable heaters. These four new series of hot nozzles with 30,000 ladders are widely used. 04C0 1 series replaced the CA series hot nozzles without interchangeable heaters. Depending on the mold structure, the heater can now be replaced from the front end or the back end.
04 C02 series has many features, which can simplify the work of mold manufacturers. For example, the hot nozzle head separates the axial and radial positioning, saving a major step for the mold manufacturer. The anchor point is the plane of the template surface, so it is no longer necessary to adjust the intermittence at the bottom of the nozzle. The cables of the heater and thermocouple are parallel to the nozzle direction, so it is easy to replace them from the front end.
03C0 1 and 03C02 series hot nozzles are the former series, one size smaller than 04 series. 03C02 series is characterized by being fixed on the hot nozzle support plate with screws from the front end to prevent the plastic from seeping out of the distribution plate and facilitate the replacement from the front end.
HYC2508 hydraulic cylinder developed with a new series of hot nozzles has a very compact structure and all the important quality characteristics of this product series: in order to simplify assembly and ensure servo speed, the needle height can be adjusted in situ (+/- 1 mm). The rotary locking of the needle valve ensures that its tip is always accurately positioned, which is especially important for gates with free-form or inclined surfaces. The patented active cooling needle valve guide and oil chamber separation realize high stability, and the compact structure ensures that it can be used in a very limited space. Another important feature of the oil cylinder design is that it is directly installed on the diverter plate, which eliminates the possibility of deviation between the oil cylinder and the diverter plate due to thermal expansion, so it can achieve high reliability in operation. In 2006, the pneumatic model of the cylinder will be used to meet the clean room conditions. Because multi-cavity molds usually only need a hot half mold with complete wiring and pipeline layout, Sanvanti provides an efficient temperature controller so that a complete and tested system can be selected and put into use at any time.
Synventive will present its advanced hot runner system products and applications at Chinaplas, Asia's largest international rubber and plastic industry exhibition, held in Shanghai from April 26th to 29th, 2006. The exhibition will be held at Shanghai New International Expo Center in Pudong, and Saint Wanti will display the hot runner series products produced by its new factory in Suzhou at booth M0 1 in E2. The factory was established in 2004 by 30 thousand ti. It is mainly responsible for the design, manufacture and service of all system products in its Asian market. During the exhibition, the company will also hold a seminar on "Application of Hot Runner Technology in Injection Molding Process of Automobile Industry" on the morning of 28th10: 00–12: 30 (located in Room M 14 outside the e 2 Exhibition Hall), in response to customers' high concern about products in the above fields.
Introduction of Foreign plastic recycling Measures
With the rapid development of plastics industry, the recycling of waste plastics, as a measure to save energy and protect the environment, has been widely concerned. Especially in developed countries, this work started early and received obvious benefits, so it is necessary for China to learn from its experience.
America is a big plastic producer in the world. According to statistics, by 2000, the United States produced more than 34 million tons of plastics every year, and the waste plastics exceeded 6.5438+0.6 million tons. As early as the 1960s, the United States has begun extensive research on the utilization of plastic recycling, but if we don't speed up the utilization of plastic recycling, we will not be able to bear the environmental pollution and economic losses caused by the increasing waste plastics. The proportion of recycled plastic products in the United States is: packaging products account for 50%, building materials account for 18%, consumer goods account for 1 1%, automobile parts account for 5%, and electronic and electrical products account for 3%. The proportions of plastic products are polyolefin 665,438+0% and PVC 65,438+03% respectively. At the end of 1980s, the recovery rate of waste plastics in the United States was nearly 10%. According to statistics, the recovery rate of waste plastics in the United States reached more than 35% at the end of the 20th century. Among them, the energy recovery rate of burning waste plastics increased from 3% in the 1980s to18%; The waste landfill rate dropped from 96% to 37%. The United States has done a lot of work in waste plastics incineration, heat energy utilization, thermal decomposition and extraction of chemical raw materials, and achieved some results. In addition, in order to solve the problem of plastic waste, American States have taken tough measures such as legislation.
Japan is the second largest plastic producer. In 1980s, the annual discharge of waste plastics accounted for 46% of the output. It can be seen that the recycling of waste plastics has become a serious social problem in Japan. Moreover, Japan is a country with energy shortage, so it has always maintained a positive attitude towards the recycling of waste plastics. In the early 1990s, the recovery rate of waste plastics in Japan was 7%, and the utilization rate of heat energy in combustion was 35%. Japan is also in the leading position in the world in the development and application of mixed waste plastics. For example, REVERZER equipment developed by Mitsubishi Petrochemical Company can make mixed thermoplastic waste plastics containing 2% non-plastic components (such as waste paper) into various recycled products, such as grid bolts, drainage pipes, cable reels and shelves. There are about 20 such devices in Japan, and more than 30 companies in the world use this device to process recycled products.
Italy is the country with the best recycling of waste plastics in Europe. Waste plastics in Italy account for about 4% of municipal solid waste, and its recovery rate can reach 28%. Italy has also developed a mechanical device for separating waste plastics from municipal solid waste. In Italy, the recycling of waste plastics is generally to collect plastic fragments and paper together, crush the waste polyethylene products separated by dry sorting, remove metal impurities such as iron with magnetic sieve, clean, dehydrate, dry and granulate by screw extruder. Adding new materials to this recycled material can ensure that it has sufficient mechanical properties and can produce garbage bags, special-shaped materials, hollow products and so on.