The forming method of large diameter plastic pipe and its research

With the development of pipeline transportation industry, the requirements for pipeline transportation capacity are becoming higher and higher, and the application of large-diameter plastic pipe is becoming more and more extensive. The research and development of large-diameter plastic pipe with high production intensity, light quality, impact resistance and corrosion resistance is one of the main development directions of pipeline transportation in the future.

In this paper, the forming method of large diameter plastic pipe, its research status, existing problems and development trend are summarized. In view of the traditional method of large diameter plastic pipe forming problem, this paper proposes a combined with increase of material manufacturing technology of traditional molding and extrusion molding technology of large diameter plastic pipe forming new technology, the polymer melt injection pile forming, namely the role of plastic melt extrusion machine pressure, jet filled by rolling pipe and keep-off device, block formed by the constraints of the space, then the rolling device and continuous screw pile under the action of tractor molding line.

Then, according to the principle of polymer melt injection and stacking technology, a large diameter plastic pipe melt injection and stacking equipment was developed. The equipment consists of extruder, pipe forming device, tractor, control system and so on. Compared with the traditional pipe molding equipment, the equipment not only don't need extrusion die head, winding mandrel, mould, also can flexible pipe molding, can Ø molding diameter 749 ~ Ø 948 mm, 30 ~ 50 mm plastic pipe wall thickness.

The main process parameters of the molding process are analyzed, including molding temperature, screw speed, traction speed, rotation speed and pitch, etc. According to the mathematical relationship between the process parameters, the process parameters set and calculated for subsequent numerical simulation analysis and experiment are required.

According to the principle of the molding process of establishing mathematical model and geometric model, using POLYFLOW software to carry on the numerical simulation, analyzes the melt velocity distribution, temperature distribution, local flow, such as law, combined with traction speed, rotating speed, cooling to finalize the design temperature, injection molding process parameters such as temperature, numerical simulation analysis, the results of experiments with theoretical guidance significance.

Finally, according to the calculated parameters and numerical simulation analysis of the conclusion, large diameter plastic pipe melt injection pile forming experiments, including on the pipe forming ring stiffness, tensile properties and impact properties and mechanical properties test, differential scanning calorimetry analysis results, analysis of the pulling speed, rotating speed, finalize the design temperature, cooling spray forming temperature and other process parameters on the molding pipe mechanical properties, the influence of the validation of numerical simulation analysis.

In addition, the mechanical properties and molding pipe by mechanical properties compared with extrusion molding pipe sizes, the results show that through the process forming of large diameter, the mechanical properties of plastic pipe is better than that of the extrusion molding, especially the impact performance, among them, the axial impact strength is 1.6 times that of extrusion molding pipe and circumferential impact strength is 2.2 times that of the extrusion molding pipe.

Performance introduction of PTFE Plastic Corrugated Pipe Machine

PTFE Corrugated Pipe Machine

Corrugated Pipe Machine Features:

ü  Power  Consumption: 380V, 1.5KW.

ü  Frequency Control, for the adjustment of  OD: 10mm to 50mm.

ü  Wall thickness: 1-2 mm PTFE convoluted hose.

ü  Imported heating system is used.

ü  heating temperature precision: + -1 degree.

ü  Single  person can operate two machines.

ü  In case 16/18 PTFE convoluted hose hourly capacity of 15-35 meters.

Equipment Accessories Details:

ü  A main engine.

ü   host of supporting tail stock.

ü  10 special bracket of PTFE convoluted hose for the production.

ü  30 with the following specifications bellows mold set.

PTFE Convoluted Hose Features

ü  To absorb effectively vibration, noise, thermal expansion from pipeline system.

ü  To resolve minor deviation because of piping connecting and eliminate the pipeline residual stress.

ü  Applied to repeated motion in high temperature areas, good anti-fatigue performance.

ü  Good flexibility, resistant to high temperature, resistant to corrosion.

ü  Applied in the fields of petroleum, chemical industry, aerospace, metallurgy, electricity, gas, building, mechanical, construction, iron and steel, paper making, fabric, medicine, food and vessels etc.

PTFE Convoluted Hose Characteristics

PTFE (Polytetrafluorethylene) has the lowest coefficient of friction of any material known to man. PTFE tubing features unmatched chemical resistance and a non-stick surface that facilitates flow and eliminates media buildup.

One key important advantage of PTFE convoluted hose is its operating temperature range, it can easily out perform other engineering plastics by being able to perform continuously at-250°C, right up to an amazing 250°C. Another important advantage of PTFE is its outstanding co-efficient of friction, PTFE convoluted hose is in the record books as having one of the lowest friction values known to man.

PTFE convoluted hose also has excellent acid and chemical resistance. Another feature of PTFE convoluted hose is its ability to set by or due to compression. PTFE convoluted hose has excellent electrical resistance. PTFE convoluted hose is also water repellent and is often used in the manufacture of modern high performing, water repellent and breath able clothing.

PTFE Convoluted Hose Applications

PTFE convoluted hose is excellent for low friction bearings, bushes, rollers and pulleys. PTFE convoluted hose is also almost exclusively used in cryogenic components due to its ultralow operating temperatures. PTFE convoluted hose is regularly used for seals. PTFE convoluted hose has become a very important engineering plastic used within the aerospace industry and aeronautics. PTFE convoluted hose is often used within the food industry companies. Another useful application over the years has been in the use of product or component handles due to its resistance to heat and heat transfer. When an application for electrical resistance becomes too high for other materials, PTFE convoluted hose can fill a very important gap.

ü  Virgin Polytetrafluoroethylene resin ƒ

ü  Chemically inert ƒ

ü  Lowest coefficient of friction ƒ

ü  Superior dielectric strength ƒ

ü  Exceptional heat resistance ƒ

ü  Self extinguishing ƒ

ü  Non-wetting ƒ

ü   Excellent flex life ƒ

ü  Laser mark able

Applications/Markets

ü  Cable Liner ƒ

ü  Electrical Insulation ƒ

ü  Oxygen Sensor ƒ

ü  Paint Transfer ƒ

ü  Gas Sampling ƒ

ü  Laboratory

More detailed technical data sheet

                                                                                           

Measurement for shear viscosity spectrum of polymer melts by using screw extruder capillary

Most polymer materials are processed in the melt state, which involves melt flow and deformation, which not only affects the processing process itself, but also affects the final performance of the product. Therefore, the study of rheological properties of polymer materials has been a hot topic. Accurate measurement of rheological parameters is the basis of in-depth study of rheological properties.

Shear viscosity is an important parameter to characterize the rheological behavior. The so-called shear viscosity of polymer melt is the ratio of shear stress and shear rate that melt is subjected to in the process of flow. Polymer melt causes pseudoplastic fluid, and its flow behavior has the characteristics of shear thinning. It is usually necessary to use the relationship curve between shear viscosity and shear rate, namely shear viscosity spectrum, to fully reflect the processing characteristics of polymer melt.

The basic method of measuring melt viscosity is to try to make the melt flow through a long and thin capillary tube, such as a round capillary tube. The shear stress can be calculated by measuring the pressure drop at both ends of the melt as it flows through the capillary tube. The shear rate can be calculated by measuring the flux of melt per unit time. Thus the melt viscosity can be obtained.

The conventional way to get the melt out of the capillary tube is to use piston propulsion. The advantage of this method is that it USES fewer test materials and can obtain higher shear stress. The high pressure capillary rheometer is based on this principle [4].However, the disadvantage of this test method is that the material cannot be tested under the actual processing conditions, and it is difficult to obtain the rheological properties of the polymer melt when it is processed. Especially in the study of blending modification of several polymer materials, the polymer melt needs the strong shearing action of screw to achieve the purpose of blending. High pressure capillary rheometer is not suitable for testing such materials.

The screw extrusion capillary rheological test device can solve the above problems. The device USES the propulsive force of the screw to make the polymer melt flow through the capillary tube. Therefore, the shear viscosity of polymer melt can be measured under conditions closer to real processing. This method is particularly suitable for the measurement of the rheological properties of thermoplastic materials and their mixtures. Because the measurement simulates the real experimental environment, the obtained test parameters can more accurately describe the behavior of materials in actual processing.

Shear viscosity spectra of polymer melts can be measured using specialized test instruments, such as high pressure capillary rheometers, or combined revolutions. However, these devices are expensive and limited in practical use, especially in the application of large-scale industrial production. In fact, it is not necessary to rely on the special test instrument, as long as the shear viscosity test principle, you can use a simple small single-screw extruder and capillary mold, constitute a low-cost shear viscosity spectrum test device. Combined with computer data processing, the shear viscosity spectrum of polymer melt can be easily and quickly obtained. This method is especially suitable for small and medium-sized enterprises to carry out product development and raw material inspection.

Polymer plasticized compounding extruder screw design

Screw is the most important part of extruder, can be said to be the heart of the extruder, it can directly affect the application of the extruder and production efficiency. The performance of screw determines the productivity, plasticizing quality, dispersion of filler, melt temperature and power consumption of an extruder. Through the screw rotation, the polymer plastic can be extruded, and the plastic can move, pressurize and obtain some heat from friction in the cylinder. During the movement of the cylinder, the plastic can be mixed and plasticized.

1.     The screw structure of polymer plasticizing and mixing extruder.

During processing, when the material moves forward along the screw, it experiences changes in temperature, pressure, viscosity, etc., which are different within the full length range of the screw. There are three physical states of   polymer plastic in extruder: glass state, high elastic state and viscous flow state. In order to adapt to the requirements of different states and according to the changing characteristics of the material, the screw can be divided into three sections: feed section, compress section and homogenize section.

The function of the feeding section is to feed the material supplied by the hopper to the compression section. During the movement of the plastic, it generally remains a solid state and partially melts due to heat. The length of the feeding section varies with the type of plastic. Compression section (transfer section) is the role of physical material pressure, so that the material from solid into molten, well out of the air in the material; In order to adapt to the characteristics of reducing the volume when pushing the gas in the material back to the feeding section, pressing the material and melting the material, the screw in this section should produce greater shearing effect and compression of the plastic. 

The function of the homogenizing section (metering section) is to feed the molten material to the machine head at constant volume (volume) and pressure so that it is formed in the mouth mold. The volume of the spiral groove in the homogenizing section is the same as that in the feeding section.

In order to avoid material retention in the end of the screw head dead corner, causing decomposition, screw head is often designed into a cone or semicircle; Some screw homogenization section is - the surface is completely smooth body called torpedo head, but there are also engraved grooves or milling patterns. The torpedo head has the function of stirring and controlling the material, eliminating pulsating (pulsating) phenomenon in the flow, reducing the thickness of the material layer with increasing the pressure of the material, improving the heating condition, and further improving the screw plasticizing efficiency. 

According to melt transport theory, melt flows in the screw homogenization section in four forms, and the flow of molten material in the screw groove is a combination of these four flows: positive flow -- plastic melt flows between the cylinder and the screw in the direction of the screw groove toward the machine head. Counter-current flow direction is opposite to the positive flow, which is caused by the pressure gradient caused by the resistance of the nose, porous plate and filter plate. The flow of the melt in a direction perpendicular to the thread wall affects the mixing and heat exchange of the melt during extrusion. Leakage flow - a backflow formed by the pressure gradient between the screw and the cylinder, along the axial direction of the screw. Different flow patterns have important effects on the mixing uniformity of polymers.

Screw diameter and the determination of structural form, mainly according to the production of product output, specifications, types of processed materials and various structural screw characteristics to determine. Generally, the feeding section of the screw has a deeper groove and the groove depth is unchanged, compression section (melt section) of the screw groove depth along the direction of discharge from the deep to shallow, metering section (homogenized section) of the screw has a shallow groove and the groove depth is unchanged.

2.     The screw material.

Screw is the key part of extruder, as the material of screw must have high temperature resistance, wear resistance, corrosion resistance, high strength and other characteristics, at the same time should have good cutting performance, heat treatment residual stress, small thermal deformation and other characteristics. For extruder screw material, there are specific requirements as follows:

(1)   High mechanical properties. To have enough strength, to adapt to high temperature, high pressure working conditions, improve the service life of the screw.

(2)   Good machining performance. Good machining performance and heat treatment performance.

(3)   Good corrosion and wear resistance.

(4)   Easy to draw.

Polymer plastic properties

1.Definition

The main components of polymer plastics are mainly polymer compounds, whose molecular weight is about 1 000, which is only for the physical concept. At present, polymer plastics are widely used, but the daily use of plastic is synthesized by polymer compounds, usually called high or macromolecule, is synthesized by monomer raw materials or raw materials into integrated materials, and through the later development, and fusion resin, color, stabilizer and other additives. The shape of polymer plastic can be changed freely and can be designed according to the user's requirements.

2.Characteristics

Polymer plastics not only have their own unique, that is, arbitrary changes in the shape, but also have viscoelasticity. Polymer plastic, if subjected to external forces, its body will produce high elastic deformation, viscous flow, polymer plastic deformation is mainly related to time. In addition, polymer plastic also has high specific strength, low strength and other characteristics, the strength of polymer plastic is generally lower, but its density is lower, so the strength becomes higher. Polymer has many characteristics, such as high stability, high wear resistance, expansion, high insulation, so it is widely used in various fields, by many people's favor.

The types of polymer plastics are also diverse. At present, the classification of polymer plastics in China mainly includes seven categories: rubber, polymer coatings, polymer materials, matrix composites, plastics, fibers and plastics.

a.   Rubber.

The price of rubber molecular chain is small, flexible, this is from the point of view of the field of physics. Rubber with the size of the external force will change its shape, with instability, if the external force removed, the original state of rubber can be quickly restored.

b.  Polymer adhesive.

The adhesive materials of polymer adhesive are mainly natural compounds. In practice, it is usually divided into two kinds: natural, synthetic adhesive. The most widely used is synthetic adhesive.

c.   polymer coating.

The main components of polymer coatings are mainly polymers, which are made in a relatively simple way, mainly adding solvents or additives in its production process. Polymer coating is divided into 3 kinds commonly, namely grease, synthetic resin and natural resin, often use in daily life.

d.  polymer materials.

The commonly used high molecular weight materials mainly include high molecular enzyme and high molecular transparent materials. Polymer materials have certain functions: energy, material, information conversion, transmission and magnetism.

e.   fiber.

Fiber is common in daily life, usually divided into two kinds: natural fiber and chemical fiber. Fiber has the characteristics of small deformation force, small secondary valence force and high modulus in physical concept.

f.    Plastics.

Plastic is a kind of material that USES more at present, also be the commonest material. The main components of plastics are usually synthetic resins, natural polymers, and the integration of other additives, such as plasticizers, fillers and so on. Plastic is generally based on synthetic resin, so it can be divided into thermosetting plastic, thermoplastic.

3. Physical properties

In general, if the polymer plastic placed in isothermal conditions, easy to produce the product. In the actual processing, the crystallization temperature is not completely consistent. If the crystallization temperature difference is large, it will affect the crystallization process. At the same time, high stress is often formed in the process of spinning forming, film stretching forming and extrusion forming, which leads to the tendency of accelerating the product. In addition, plastics apply techniques in shear stress. And under the influence of tensile stress, the melt will form longer fibrous crystals. The higher the stress and strain rates are, the more elongated chains and the higher the melting point.

4. Chemical properties

Generally speaking, if the polymer plastics are placed in high stress and high temperature conditions, the molecular structure will have some changes. In this reaction, polymer plastics usually release a large amount of degraded substances, thus releasing more harmful substances. To this end, in the processing should be clear raw material indicators, choose high-quality raw materials. At the same time, a small amount of antioxidant and stabilizer can be added in the formula to improve the anti-degradation performance of the polymer.

Effect of PTFE on Properties of PE-UHMW

In order to obtain ultra high molecular weight polyethylene (PE-UHMW) matrix composites which get high wearresistance and high heat resistance , and the poly tetrafluorethylene (PTFE) was modifed to improve the wear resistance and heatresistance of PE-UHMW. The test results show that the Shore hardness of the composite reach the highest that is 67.08, and thewear resistance is the best when the mass fraction of PTFE is 5%, the friction coeficient to 15CrMoV steel is 0.235 and the wearrate is 0.081 4%, and the thermal deformation temperature of the composite is increased by 21% when the load is 10.0 N and thedeformation amount is 0.06 mm. Under the action of KH-~550 coupling agent, the PTFE can achieves a uniform distribution in the PE-UHMW matrix, and the formation of dense binding. With the increase of PTFE content, the creep of the composites is graduallyincreased.

Since its inception, ultra-high molecular weight polyethylene (PE-UHMW) has been widely used in mechanical textile, medicine and other fields with its excellent physical and mechanical properties, becoming an engineering plastic that can replace metal materials. PE-UHMW has good impact resistance, wear resistance, chemical corrosion resistance, self-lubrication and other properties. However, PE-UHMW's low hardness and thermal deformation temperature defects cannot meet some high requirements of field applications. At present, modification methods of PE-UHMW mainly focus on chemical modification and physical modification. People often add organic and inorganic particles or fibers to PE-UHMW to improve its performance. By contrast, organic modifiers are easier to form firm bonds with PE-UHMW molecular chains.

Polytetrafluoroethylene (PTFE) holds the title of "the king of plastic, PTFE, with its excellent corrosion resistance, wear resistance, low friction coefficient, is only 1/5 of the polyethylene, between 0.01 ~ 0.10, as additives to improve the PE-UHMW abrasion resistance and heat resistance. It has obvious effect, Fang Zheng equality of polyoxymethylene, polyamide, PTFE linear low density polyethylene (PE-LLD) such as blending modification, the results found that Adding appropriate amount of modified PTFE can significantly improve the compatibility between PTFE and polymer. When PE-LLD is modified with PTFE, the mechanical properties, processing properties and stability of composites are greatly improved, and the friction coefficient is significantly reduced. PTFE was selected to blend and modify PE-UHMW in order to prepare composites with excellent wear resistance and heat resistance, reduce the friction coefficient of PE-UHMW and expand its application field.

Properties of molded products

Molded products have excellent electrical properties (especially anti-leakage properties), mechanical properties, heat resistance, fire resistance, chemical corrosion resistance and dimensional stability, and can be adjusted according to the needs of each component type and dosage to obtain products with special performance requirements. The main performance is as follows：

1.Electrical property

Molded plastics are widely used in high voltage electrical applications due to their arc resistance, acer performance, flame resistance, dimensional stability, moulding and low cost. The ability of arc suppression is mainly due to the presence of inert inorganic fillers such as hydrated alumina, silica and ceramic. Add a small amount of polyethylene powder (5% by weight) and use nylon fiber to improve arc resistance. In order to obtain better arc resistance, the resin and glass fiber content should be reduced to the minimum, however, such results reduce the mechanical properties.

2. Mechanical property

The mechanical properties of molding materials vary with the types and proportions of reinforced fibers and resin substrates used. In DMC, when the fiber length exceeds 6.35mm, the modification of product properties is very small.

Most SMC products are made from short-cut felt, and there is no published data on the effect of fiber length changes. Although the length of the general fiber is 50mm, this length is not necessarily suitable for all applications.

Increasing the content of reinforcing materials can improve the mechanical properties, but too much fiber content will bring inconvenience to molding. For example, when the fiber content in DMC exceeds 20%, it has little influence on its mechanical properties.

3. Heat resistance or fire resistance

Heat resistance refers to the ability of products to withstand thermal decomposition for long periods of time below the flammable temperature. "Short-term thermal strength" or "thermal strength" is related to the thermal deformation temperature of the resin. Although some fillers can improve the heat resistance of products, the heat resistance and thermal strength mainly depend on the properties of the resin. Flammability is a measure of apparent combustion, divided into "non-ignition", "self-extinguishing" and "flame-retardant" according to the ability and speed with which a material is able to extinguish easily or when the ignition source is removed. Polyester resins achieve flame resistance by adding halogen and phosphorous compounds and by using alumina hydrate as the main filler in the components.

Phenolic resins are inherently fire-resistant. Halogen compounds and phosphorous compounds, as well as HET anhydride used as hardener, can make epoxy resins flame resistant.

4.Dimensional stability

General molding materials have good dimensional stability, water absorption rate: small, thermal expansion coefficient and aluminum is very similar, when continuous exposure to high temperature, size is almost no change.

5. Corrosion resistance

The chemical resistance or corrosion resistance of molding material mainly depends on the selected resin matrix. The suitable resin and filler can be used to prepare the moulded material which can meet the requirement of resisting special bristle dew

DMC can be made of acid-resistant and alkali-resistant ligulates and acid-resistant epoxy resins. The choice of a resin for SMC is currently limited because the resin must also have a chemical structure that thickens easily. In common fillers, clay and silica have better corrosion resistance and other properties.

6.Contractility

The shrinkage of moulded material is very low after release, the typical maximum shrinkage rate is 0.004, and the shrinkage rate of many moulded materials is close to 0.001, which is mainly due to the small thermal shrinkage of glass fiber and inorganic filler. However, the combination of low-shrinkage, high-strength fibers with the resin systems commonly used for rapid curing and high thermal shrinkage results in greater stress on the resin matrix between the fibers. The collateral effects of this stress cause surface ripples, cracks, warping, and internal voids. These defects can be reduced by the use of organic fiber reinforced materials compatible with resin shrinkage or by the use of short or filamentous glass fibers.

The molding process of the press automatic Moulding Machine

Is moulded plastic processing and molding the application in the city one of the oldest technology. It has a mature production technology, equipment and mold is simple, easy to forming large products, can use multiple modes to improve the production of small parts, etc, in machinery, electronics, transportation and daily life, and many other fields has been widely used.

The market will often see a lot of kinds of Press Moulding Machine, for example: Polymer/PTFE Bush press Automatic Moulding Machine, Polymer/PTFE Flange press Automatic Moulding Machine, Polymer/PTFE gasket automatic Moulding Machine, Semi-automatic Molding Machine and so on.

Molding is widely used in the following fields:

Electrical: insulator, switch box, electrical equipment housing, insulation tools, wiring board, etc.

Automobile: lamp shade, front and rear bumper, battery bracket, engine soundproof board, etc.

Railway: window frame of vehicle, toilet components, seats, table tops, siding and roof of carriage, etc.

Construction: water tank, bath products, door panels, purification tank, building template, etc.

Bathroom: bathtub, integral bathroom equipment, integrated wash basin, etc.

And other areas of industry and agriculture.

Molding technology is a method of putting quantitative molding materials (powder, granular or fibrous plastic) into the metal mold and forming products under the action of temperature and pressure. During the molding process, heat and pressure are required to melt (or plasticize) the molding material, fill the mold cavity with flow, and make the resin solidify. The principle is that the process of pressurizing, shaping and heating depends on the closure of the heated mold.

Moulding Machine technology is the oldest molding method in plastic processing technology. Because of its long history, the molding technology has been quite mature, at present in thermosetting plastics and some thermoplastic plastics (fluoroplastics, uhmwpe, polyimide, etc.) processing is still the most widely used and the main position of the molding method. Moulded thermosetting plastic, placed in the cavity of the thermosetting plastic under the action of heat, first changed from solid to melt, melt flow under pressure with the shape of the cavity and cavity has given, as the crosslinking reaction, resin molecular weight increased, the curing degree rise, moulding material viscosity increase gradually and becomes solid, finally becomes demoulding products. Thermoplastic plastic mold pressure, in the previous stage of the situation and thermosetting Plastic the same, but because there is no cross-linking reaction, so in the flow of full cavity, the mold must be cooled to make its molten plastic into a solid with a constant strength can be demodulated into products. Because thermoplastic plastic mold pressing mold needs to alternately heating and cooling, production cycle is long, so thermoplastic products generally choose injection molding method more economic, only in the mold larger plane of Plastic products or because of the flow of thermoplastic plastic injection molding method is difficult to use molding.

In the mold press material filled with the mold cavity flow process, not only the resin flow, the reinforcement material also to flow, so the mold press molding process molding pressure is higher than other process methods, belongs to the high pressure molding. Therefore, it needs not only the hydraulic press which can control the pressure, but also the high strength, high precision and high temperature resistant metal die.

PTFE and ZnO/PTFE coatings displayed good wear resistance

Superhydrophobic surfaces that mimic surfaces found in nature, such as the lotus leaf, are an attractive research topic in various fields of study because of their numerous applications. More recent studies have focused on superhydrophobic surfaces that reduce or completely stop the accretion of ice and snow on power lines and aircraft that operate in cold regions. The superhydrophobic phenomena is usually achieved by creating a dual-scale roughness that is composed of micro- and nano-scale structures that trap air in-between themselves and reduce the surface energy of the textured surface.

The objective of this study was to assess the tribological behavior of micro/nano particle based superhydrophobic coating mixtures composed of PTFE, composite PTFE/PEEK, diatomaceous earth (DE), and composite PTFE/ZnO that can be potential candidates for anti-wetting and anti-icing applications for transportation systems. A contact profilometer was used to measure and characterize the average roughness and thickness of coatings. Coating wettability was assessed by measuring the tangent-line contact angle of static water drops on coated surfaces. Friction and cyclic abrasive wear tests were conducted via ball-on-flat tribometer using a spherical tungsten probe at room temperature. Scanning electron microscopy was used to characterize the physical and chemical properties of the coatings and identify the wear mechanisms.

The results showed that all coatings except ZnO/PTFE exhibited superhydrophobicity. Abrasive wear mechanisms were the dominant modes for the coatings. PTFE and ZnO/PTFE coatings displayed good wear resistance, superior to that of the DE and PTFE/PEEK coatings.

SUKO is attending a manufacturing expo in Bangkok

Are you still worried about semi-automatic machines on the market? Are you still anxious about the equipment for Polymer/PTFE/UHMWPE products? This is a good opportunity now!

SUKO is attending the Manufacturing Expo(ME) in Bangkok, Thailand on June19-22, 2019. ME is an event dedicated to machinery and technology for manufacturing and supporting industries, It fully reflects the level of machinery manufacturing and mechanical equipment development in Asian.

Here are some popular products we produced: Auto extrusion/bush molding machine, Auto Gasket Machine, UHMWPE Rod Extruder, PTFE Tube Extruder, etc. They are all automatic machines, which help customers improve productivity and quality. These products also have longer working life and are friendly to environment. 

The specific marketing advantages are as follows:

ü  PTFE Automatic Press Molding Machine-It is suitable for pipe and rod, it has PLC control and screen touch system. Furthermore, if PTFE powder is exhausted, it will  alarm Automatically.

ü  Auto Gasket Machine-It has advantages of environmental protection, time saving, high efficiency, long service life, good heat dissipation and good quality of accessories.

ü  UHMWPE Rod Extruder- It can extrude  3-9 million molecular weight of raw materials.

Come to this event, Here are the newest innovations and solutions by 2,400 brands from 46 countries.

Come to our booth, We have professional and technical personnel to solve your problems immediately. What’s more, plenty of advanced and complete equipment for your choice, such as PTFE AutomaticPress Molding Machine, Auto Gasket Machine, UHMWPE/PTFE Rod Extruder and so on. In addition, at the international exhibition, you can consult a wide range of topics for your needs, or compare a large amount of manufacturers to select your favorite devices.

Detailed exhibition information is as follows.

Time：June 19-22, 2019

Address：Bangkok International Trade and Exhibition Centre，

88 Bangna-Trad Road (Km.1), Bangna, Bangkok 10260, Thailand

Booth Number：3D34

We sincerely hope to establish long-term cooperation with you, we will try our best to provide high quality and excellent service, we will cherish every opportunity to cooperate with you!

Looking forward to your visit!

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What is the PFA

I. What is the PFA?

The English name of PFA is Polyfluoroalkoxy, or tetrafluoroethylene perfluoroalkoxyethylene ether copolymer (perfluoroalkylate, soluble polytetrafluoroethylene).PFA resin is relatively new fluoroplastic that can be processed by melting. PFA, FEP and PTFE have similar chemical properties, but FEP can only be used below 200 degrees, and PTFE cannot be injected. 【this resource was first published by China fluoroplastics network.】

1. Specific gravity: 2.13-2.167g/cubic centimeter

2. Molding shrinkage rate :3.1-7.7%

3. Molding temperature: 350-400℃

4. The melting point of PFA is about 580F and the density is 2.13-2.16g /cc (g/ cubic centimeter).

II. Features and main USES of PFA

PFA, commonly known as fusible PTFE, is the crown of fluoroplastics with various properties and USES similar to FEP.Widely used in semiconductor industry, as well as medical, chemical corrosion protection, automotive and other fields.

PFA products include granular products for molding and extrusion, and powdery products for rotating molding and coating.Its semi-finished products are membrane, plate, rod and pipe.PFA resin distributed in the American market includes Teflon of DUPOut, Neoflon of Daikin, Hthen of Ansimont and Hostafl of HOechst Celanese.

1. Main USES of PFA:

(1). Suitable for making corrosion resistant parts, wear - resistant parts, seals, insulation parts and medical equipment parts.

(2). High temperature wire, cable insulation layer, anti-corrosion equipment, sealing materials, pump valve bushing, and chemical containers.

2. Molding performance

(1). Crystallization material, small moisture absorption.Products may be processed by the usual thermoplastic processing method.

(2). Poor liquidity, easy decomposition, decomposition produced corrosion gas.It is advisable to strictly control the molding temperature not to exceed 475 degrees, the mold should be heated to 150-200 degrees, the pouring system should have little resistance to the material flow.

(3). Translucent granule, injection molding, extrusion molding.Forming temperature 350-400 degrees, 475 degrees above easy to cause color or bubble.And notice that it's harder to get out of the mold.

(4). Because the molten material on the metal corrosion effect, long-term production, the mold needs to electroplate chromium treatment.

3. Material performance

1. PFA is a copolymer of a small amount of perfluoropropyl perfluoroethylene ether and polytetrafluoroethylene.The melt bond is increased, the solution viscosity is decreased, and the performance is not changed compared with ptfe.The resin can be processed into products directly by ordinary thermoplastic molding.

2, long-term use temperature -80- 260 degrees, excellent chemical corrosion resistance, corrosion resistance to all chemicals, friction coefficient in the lowest plastic, and very good electrical performance, its electrical insulation is not affected by temperature, "plastic king" said.

3. Its chemical resistance is similar to ptfe and better than vinylidene fluoride.

4. Its creep resistance and compression strength are better than ptfe, with high tensile strength and elongation up to 100-300%.Good dielectric property, excellent radiation resistance.

5, non-toxic: with physiological inertia, can be implanted in the human body.