We have one earth only. These days, the United Nations Climate Change Conference Copenhagen 2009 is going on. Between China as the representative of the developing countries and the United States, Europe and Japan, developed countries as the representative of the developed countries are having the heated debate each other. Because the developed countries are in an attempt to overule Kyoto Protocol so that China, Indian and many Africa countries wanna quit of this conference. Here I would like to express is that, whether developed or developing countries, we have only one Earth. In fact, we are in the same boat, just as the same as the Titanic. Only developed countries in the first class, and the developing countries are in economy class. It is only through helping each other in order to tide over the difficulties, rather than through political tactics to achieve intentions.

I think that these arguments not only between developed and developing countries, but the rich and the poor arguments. Can you image one country which has 85% families can not afford to buy a house (Chinese Academy of Social Sciences, blue book) to undertake a major national environmental obligations? It is not only unfair, this is fundamentally anti-science. People who have heard of Maslow's theory (Maslow's hierarchy of needs), they know   human needs are divided into various stages. The first is physiological needs such as food, water, air, etc., then security needs, such as personal safety, sense of space requirements, property safety, health insurance. And then the social needs, including friendship, love. Now in China, food and clothing should be said that has been resolved, that is, the lowest level of Maslow's needs pyramid has been resolved. However, security requirements, there are some unresolved. Our health care system is not good, medical care difficult and expensive is still one of the major social conflicts. Although we have a democratic system looks beautiful, but the execution of the democratic system is not good. Various legal systems are not perfect, the effect of the implementation is even worse, such as property law. Coupled with higher and higher outrageous housing prices has kept the people away from their house dream. All these make the families do not have the sense of security. In such a social environment, you ask people to make more contribution for global environment protection, it is impossible to achieve. I think the contribution to environmental protection is in the fourth level of Maslow's theory belongs to others respect and self-esteem areas. Therefore, only if they meet the physiological needs, security needs, and emotional needs of the foundation. It would good to consider environmental protection issues.

What I have said these issues and not just China's problem is the vast majority of problems of developing countries, and even in developed countries have these problems too, just more or less. Copenhagen conference is undoubtedly a political show of Game Theory, but I would like to remind the developed countries is that, perhaps you have a lot of political tricks. But developing countries have the right to withdraw from the game, once the developing countries out of the game, then the result of the game is no winner. Environmental issue is the problem of all mankind. We have more than 200 countries, seven continents, four grand oceans, three colors people, two genders, but we have only one Earth.

This United Nations Climate Change Conference Copenhagen 2009 has more worldwide attentions than before. It is also a sign to speed up the research and development of new materials and energy save materials. USEON Foam Extrusion Team has been devoting to energy save materials. We have a lot of cooperation with Institute of Plastics Processing & Application of Light Industry, Beijing University of Chemical Technology, and East China University of Science and Technology. We developed CO2 foam Extruded Polystyrene production line (XPS production line), and still researching for high thickness Polypropylene and Polyethylene sheet. Our BTB Recycle Team has been engaged in PET recycle extrusion technology, it is also a good product for energy save. In my opinion, Chinese extruders will make great contribution to developing countries. Because Chinese machine has the best cost-performance. No matter single screw extruder,twin screw extruder or complete production line. Our price is even less than 1/4 European price with the same productivity. There are 85% people are living in developing countries. That means the majority of worldwide people are living in developing countries. Of course, developing countries need eco-friendly product, but it should be affordable. So the developed countries should take out more helps to developing countries. Since we have the different living status, but we will have the same destiny when global climate become worse and worse.

During 18th to 19th December 2009, as the typical representative of XPS production line supplier in China, our company has been invited to participate in HCFCs alternatives technology seminar of XPS production organized by Material Science & Engineering Department of Beijing Technology & Business University (Institute of Plastics Processing & Application of Light Industry) collaborated with Ministry of Environmental Protection of China.

In this seminar, the organizer Dr. Wang expressed the requirements of government. He said our Premier Wen jiabao has said in Copenhagen that no matter United Nations Climate Change Conference Copenhagen can get a positive conclusion or not, we will still persist in our environmental protection strategic plan to reduce the CO2 emission. The ban of usage of HCFCs or HFCs will come earlier than we expected. So HCFCs alternatives technology of XPS production becomes more urgent. In the seminar, our company has been encouraged by the officer from Ministry of Environmental Protection of China because our efforts and contribution in CO2 foam XPS technology. In the meanwhile of this seminar, almost all experts have got a common conclusion about CO2 foam XPS production line that twin screw extruder plus single screw extruder tandem structure is the best choice for CO2 foam XPS production now. The experts also discussed the present China National Standard of XPS board. Comparing to European standard DIN EN 13164, China National Standards is more criticized. China National Standard Press Center will consider to change GB (China National Standard) into more tolerant in thermal conductivity. We also hope this new standard can carry out earlier. It will help CO2 foamed XPS board goes to the domestic market quickly. Actually, the quality of our CO2 foamed XPS board has been accepted by Australia customer and it also can meet European standard.

A Twin Screw Extruder not only shares the common operation principles with a single screw extruder: solid conveying, melting, admixture of pressurizing and pumping up, etc., but also owns its distinct characteristics. There are several factors that tackle the study of basic principles of co-rotating twin screw extruder, such as the late research of extrusion theory, various types, complex screw geometry, and complicated extruding process.

principles with a single screw extruder: solid conveying, melting, admixture of pressurizing and pumping up, etc., but also owns its distinct characteristics. There are several factors that tackle the study of basic principles of co-rotating twin screw extruder, such as the late research of extrusion theory, various types, complex screw geometry, and complicated extruding process.

Basically speaking, the study of twin screw extruding theory is still at the initial stage, which indicates that the study is still more art than science. There are three links of its operation principles according to the extruding process:

1. The design of twin screw extruder and optimization of extruding process could be improved by material change laws, conveying theory ,including convey of solid and melt, also gas filling and ejecting characteristics, which can form a mathematics and physical model in the extruding process.
2. Make sure to have a clear command of the change regulation of two or more polymers and materials in the extruding process, their mixing state, the process of their structural change, and the relationship between final mixtures and their functions.
3. A model that is helpful for the molding-filling process can be formed by   the internal relationship among the reaction process, speed, function of extruding process and screw’s structure, as well as operation condition.

The development of twin screw extruders: it was first invented in 1930s in Italy, while in the late 1960s and early 1970s, it experienced a rapid development. With the development of RPVC products, counter-rotating twin screw extruder came into being; while co-rotating twin screw extruder appeared, companying with the polymer modification. It is useful to study the twin screw extruding theory, because it can not only be applied effectively, but also has become a consensus and a hot research in the world.

Pelletizing machine is a kind of material that can be shaped into specific molding machine. Are widely used in chemical, petrochemical, pharmaceutical, food, building materials, mining and metallurgy, environmental protection, printing and dyeing, ceramics, rubber, plastics and other fields.

Pelletizing machine Notes

First,note
1, granulation confidential positive functioning; to avoid the reverse.
2, granulator avoid cold machine running an empty stomach, you must heat engine feeding operation, this would avoid the sticky bar (hold-axis) phenomenon.
3, granulator feed mouth, put holes in iron and other debris is prohibited to enter. So as to avoid an accident, affecting production.
Second, the working process of granulating machine Attention
1, and pay attention to body temperature changes, touch hands with a clean left the note should immediately warming. Until the note attempts to change the normal.
2, reducer bearing parts of burned hands, or when accompanied by the noise should be timely maintenance, and added fuel.

Single screw extruders are the most common type of screw extruder. Single screw extruders use a single screw in combination with a cylinder or barrel for providing the mixing and conveyance through the extruder die plate at the end other end of the extruder to form the final product shape. There a numerous combination of screws and barrels to provide the necessary mixing, texturizing and kneading of the product to make it suitable for shaping through a die plate and sized to a required length.

Screw extruders consist of drive part and processing part.
Drive part includes the reduction unit and motor.AC motor or DC motor is available.
Processing part consisted of barrel,screw parts and two pieces of co-rotating screw shaft.There are closing barrel,feeding barrel,venting barrel.Solid and liquid material can be fed by feeding hopper or liquid injector.The screw parts array can be adjusted according processing technology,it can perform transmitting, plastizing, compounding,shearing,venting,and dehumidifying.Granula,powder,liquid can be fed by main feeder,side feeder,or liquid injecting unit.Multipath Loss-in-weight feeding system is also available.

Plastic injection molding machine that can be classified as reciprocating extruder  are among the most widely used machines in industry. However, most studies in the injector design were based on steady state models developed for reciprocating extruder  that involved no reciprocation. This over-simplified model leaves out the most important aspect of reciprocation. The authors of this paper have derived a transient melting model that takes care of the change from the conventional steady extrusion to that of a discontinuous transient process. This paper describes simulations conducted on the derived model to explain observation that cannot be explained by the steady extrusion model in practical experiments. The simulation was conducted by using parameters given in Donovan's experiment [Polym Engng, 11 (1971) 353]. The simulation results are found to qualitatively match with the experimental results. It proves the validity of the model. Simulation has also been conducted with the model on materials that their viscosities are temperature and shear rate dependent. The result has shown that screw rotation speed, screw axial movement speed, barrel thickness, barrel heat capacity, temperature of heater and polymer are factors affecting the melting speed and the transient effects.

Precise feeding of a rubber compound into a twin-screw compounding extruder is achieved by using a short single-screw rubber processing extruder with downstream gear pump.

Hannover, Germany-based KraussMaffei Berstorff has developed an innovative system for TPE-V production by merging its engineering capabilities in rubber processing and compounding.

A compounding extruder with downstream gear pump ensures precise feeding of the rubber compound into the twin-screw compounding extruder.

The single screw extruder and gear pump combination provides outstanding high precision feeding performance, said KraussMaffei.

Bale rubber cut into strips can be processed directly instead of having to use pellets.

Process efficiency and cost-effectiveness are substantially improved since time-consuming and expensive pre-pelletising of the rubber is no longer necessary.

The benefits offered by the new KraussMaffei Berstorff system are especially significant in the production of soft TPE-V types.

In many cases, soft TPE-Vs are produced using oil-extended EPDM rubber, which is rather difficult to pelletise owing to its sticky surface and because separating agents must be used.

* Precise rubber feeding - the single-screw extruder ensures reliable feeding and pre-compounding of the rubber.

A pressure-based control system adjusts the extruder speed in such a way that the downstream gear pump is always completely filled.

The gear pump is designed to achieve precise volumetric feeding of the rubber into the twin-screw compounding extruder.

* Compounding process - inside the twin-screw compounding extruder, the rubber is mixed with the thermoplastics material, and the cross-linking reaction of the rubber phase takes place to form the TPE-V required.

The phase morphology and the physical properties of the finished TPE-V are determined by the configuration of the twin-screw extruder.

The first extruder section is designed for the compounding and mixing of the main recipe components, usually EPDM and PP, and for the incorporation of additives and processing oils.

Dynamic cross-linking takes place in the downstream mixing zones of the extruder.

The last extruder section is used for vacuum degassing.

* Combination with internal mixer - the new system can also be used with an internal mixer.

In this case, rubber, fillers, plasticiser oils and additives are pre-mixed in the internal mixer and fed into the extruder in the form of strips.

With this solution, the twin-screw compounding extruder is merely required to mix in the thermoplastics material and, if necessary, the cross-linking agent and to perform the dynamic vulcanisation process.

* More about TPE - owing to their superior material properties, thermoplastics elastomers (TPEs) are becoming increasingly important, said KraussMaffei.

PET bottle recycle machine has wide applications in various field. This type of PET bottle recycle machine inherits all the merits of the original model, enhanced by new technology. Compared with other PET bottle recycle machine, our PET bottle recycle machine  enjoys many advantages including: more reasonable structure, more compact appearance, smoother operating, higher efficiency and is easy to operate and maintain. PET bottle recycle machine has wide adoptablity, is an ideal PET bottle recycling machine for you to convert into production.

The PET bottle recycle machine is designed to wash and clean the recycled PET bottles, such as the mineral water bottles, pesi bottles, oil bottles, etc. The clean recycled PET bottle flakes processed by PET bottle processing machine can be used to produce the polyester staple fiber, PET strap band, granules, PET transparent film and sheets, etc. The top class PET bottle flakes can be used to mould the PET bottles again.

The composition of extrusion machines:
Plastic extrusion machine is the host, which is extrusion system, transmission system and the heating and cooling system.
 Extrusion system including the screw, barrel, hopper, nose, and die, plastics extrusion systems through plastics melt into a uniform, and in the process established under the pressure, the screw continuous extrusion die.
(1) screw: it is the most important parts of the extruder, which extruder is directly related to the scope of application and productivity, from high-strength alloy steel made of corrosion-resistant.
(2) Barrel: a metal cylinder, the general use of heat-resistant, high strength, strong wear resistance, corrosion-resistant alloy steel or alloy steel lined composite steel pipe made of. Barrel and screw with the crushing realization of the plastic, softening, melting, plastics, exhaust, and compaction, and to evenly transfer molding system for plastic material, generally the length of its barrel diameter of 15 ~ 30 times in order to be fully plastic heating and the principle of full plastics.
(3) hopper: hopper at the bottom with cut-off device, in order to adjust and cut off the material flow, as the hopper with the side hole and metering device calibration.
(4) head and die: inside the nose by the sets of alloy steel and carbon steel jacket structure, there is mold inside the nose, the role of head rotation is to melt the plastic into a parallel straight-line movements, steady uniform Import module sets and give the necessary molding plastic pressure, plastic bins in the machine Plasticating compaction, porous plate by the flow along a certain flow of the nose through the nose neck mold, mold core set of appropriate to form a cross-section of the annular gap decreases, so that the core line of plastic melt in the surrounding dense tubular continuous coating. Nose in order to ensure a reasonable flow of plastic to eliminate the accumulation of plastic corners, often have a shunt placement sleeve, plastic extruder to eliminate pressure fluctuations, but also pressure settings are Central. Machine is also equipped with a die head and adjust the device calibration, easy adjustment and calibration, and core concentricity of the die sets.
Extruder die in accordance with the material flow direction and the angle between the centerline of screw will head into the head angle (angle of 120o), and at right angles to the head. The nose of the shell is fixed with bolts in the machine body, the die head core sitting there, and a fixed nut in the nose into the line port, the front seat core with core, core and core block the center of a hole for the line through the core; in the front nose ring with pressure are used to balance pressure; squeeze forming part of package sets from the mold and die sets of the composition of blocks, the location of die sets can be bolted through the support to adjustment mode to adjust the sets of the relative positions of core, easy to adjust the thickness of the clad extrusion uniformity. Head equipped with external heating device and temperature measuring devices.

Twin screw extruder Two screws, side by side, are placed within the extruder barrel; they are either counter-rotating or co-rotating. Counter-rotating twin screw extruders are used primarily for processing PVC products such as pipe, siding, sheet, pellets, and film. The co-rotating units are used for compounding materials where thorough mixing and high output rates are important. The twin screw unit resembles a positive displacement screw pump. It conveys the material at low speeds with controlled shear. The positive action assures that all portions of the material experience a uniform residence time.

Single screw extrusion is one of the core operations in polymer processing and is also a key component in many other processing operations. The foremost goal of a single screw extrusion process is to build pressure in a polymer melt so that it can be extruded through a die or injected into a mold. Most machines are plasticating: they bring in solids in pellet or powder form and melt them as well as building pressure.The most complete and up-to-date reference is probably:
Chris Rauwendaal, Polymer Extrusion, Hanser Publishers, New York (1990) ISBN 3-446-16080-9.