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.

Study on related properties of ptfe

1.  Properties of polytetrafluoroethylene modified epdm rubber

EPDM modified by polytetrafluoroethylene (PTFE) and nano silicon dioxide (SiO2) was prepared by vulcanization. Scanning electron microscope and infrared spectrum showed that PTFE and EPDM had good compatibility. DSC test showed that the composite had a unique glass transition temperature. When PTFE is added in 5 parts, PTFE and EPDM have a good compatibility. At this time, mechanical properties of epdm-ptfe reach the highest, and its tensile strength, elongation at break, hardness and tear strength are 22.42mpa, 588.91%, 82.0° and 49.60 kN/m respectively. Thermogravimetric analysis and aging experiments show that the aging and heat resistance of PTFE are improved. The mechanical properties of EPDM were also significantly improved after adding 5 parts of nano SiO2.

2.  Structure and properties of polytetrafluoroethylene hot-rolled fiber membrane

PTFE fiber membranes were prepared by hot rolling process and orthogonal design. Scanning electron microscope (SEM) was used to observe the surface morphology of the fiber membrane, and its thickness, permeability, aperture, porosity, tensile properties, acid and alkali corrosion resistance were tested and evaluated. The results showed that PTFE hot-rolled fiber film thickness was 0.12 ~ 0.15 mm, permeability was 80 ~ 101 mm/s, pore diameter was 14 ~ 17 ms, porosity was 14.57% ~ 27.04%, fracture strength was 38 ~ 59 N, elongation at break was 30% ~ 38%.In the 9 kinds of fiber membranes, there are still a lot of fibrous structures except the fiber melting on some surfaces. After acid and alkali treatment, the tensile properties of the fiber membrane remained unchanged. According to the orthogonal test results, the fiber mesh density has the greatest influence on the thickness, permeability, pore diameter and tensile properties of the fiber membrane, and with the increase of fiber mesh density, the permeability and pore diameter of the fiber membrane decrease, while the thickness and fracture strength increase.

3.  Structure and properties of polytetrafluoroethylene/polypropylene hybrid melt jet filter material

In order to extend the storage time of static charge on the surface of polypropylene (PP) melt-blown materials, the storage capacity of static charge was improved by organic hybridization. In the experiment, PTFE ultrafine powder and PP slice were mixed to granulate in a certain proportion, and different nonwoven materials were obtained by melt-jet molding process. The structure and performance of the nonwoven materials, such as apparent morphology, micropores, surface electrostatic potential and filtration efficiency, were studied, and external corona electret technology was adopted to make the material surface carry static charge. The test results show that adding PTFE can effectively improve the storage capacity of static charge of melt-jet PP nonwoven materials, and when PTFE mass fraction is 0.1%, the surface static voltage is the highest, the filtration performance is the best and the static charge stability is the best.

Introduction to steel lined teflon tube

Firstly, imported PTFE powder is used to push (squeeze) the teflon tube, and then it is forced into seamless steel tube (liner outer diameter is slightly larger than tube inner diameter 1.5-2mm) to form a tight liner without clearance.In order to eliminate the pressure, it is put in the furnace, heated to 180℃ for constant temperature treatment, so that it can be used in the temperature below 180℃.At the same time, the axial tensile strength of push tube is better than that of wound tube.The pipeline has ideal positive and negative pressure resistance.

PTFE powder moulding method is a kind of body, such as pressure, such as isothermal manufacturing technology, through the extruded tube (loose lining, lining) of PTFE, PTFE belt winding and winding plus steel wire, and steel net within process of evolution, the PTFE lining powder compression molding technology is by far the PTFE lining the latest fifth-generation products, can be at a higher pressure, high temperature, strong corrosion under the conditions of use, the temperature below 200 ℃ and vacuum is 0.096 MPa, quenching heat or alternating operation, won't make PTFE grassroots fall off, the drum, expansion deformation of flat, thereby the fluorine steel body.

Chemical properties of steel lined teflon tube:

Air aging resistance: radiation resistance and low permeability: long-term exposure to the atmosphere, the surface and performance remain unchanged.

Non-flammability: the oxygen limit index is below 90.

Acid and alkali resistance: insoluble in strong acids, strong bases and organic solvents.

Oxidation resistance: resistant to corrosion of strong oxidants.

Steel lined teflon tube working characteristics:

Performance: working temperature of medium: -100℃~-250℃

Working pressure of medium: positive pressure: 2.5mpa, with negative pressure of 70KPa at normal temperature

Corrosion resistance: steel ptfe composite pipe, in addition to molten metal lithium, potassium, sodium, chlorine trifluoride, high temperature trifluoride oxygen, high flow rate of liquid fluorine, it can resist almost all chemical media, including concentrated nitric acid and aqua aqua corrosion, it can work for a long time in the temperature of 230℃-250℃.Steel polyvinylidene fluoride or other vinylidene fluoride composite pipe, halogen, halogenated hydrocarbon, strong oxidant, boiling acid, alkali, a variety of organic solvents have good corrosion resistance, but not resistant to smoke sulfuric acid, concentrated hot sulfuric acid and nitric acid, 90℃ above ketone, ester, amine and high temperature sulfonating agent corrosion.

Application fields of steel lined teflon pipeline:

Steel lined tetrafluoroethylene pipe is suitable for strong corrosive gas and liquid under high temperature, other types of steel plastic composite pipe and metal pipe are not suitable for conveying medium, steel ptfe composite pipe is suitable for all.In addition, steel polyvinylidene fluoride composite pipe suitable for the transport of corrosive media at the working temperature of -40℃~+150℃.

PTFE (teflon) coating

PTFE high performance special coating is based on polytetrafluoroethylene resin fluorocoating, the English name is Teflon, because of the pronunciation, often called Teflon and so on (all for Teflon translation). PTFE (teflon) coating is a unique high performance coating, combining heat resistance, chemical inertia, excellent insulation stability and low friction, with comprehensive advantages that no other coating can compete with, its application flexibility makes it can be used in almost all shapes and sizes of products.

Teflon is divided into PTFE, FEP, PFA and ETFE basic types:

· Teflon PTFE: PTFE (Polyfluortetraethylene) non-stick coating can be used continuously at 260℃, with maximum operating temperature of 290-300℃, extremely low friction coefficient, good wear resistance and excellent chemical stability.

· Teflon FEP: FEP (Ethylene fluoride propylene copolymer) non-stick coating forms non-porous film in the melting flow during baking, with excellent chemical stability and excellent non-stick characteristics, and the maximum operating temperature is 200℃.

· Teflon PFA: PFA (Perfluoroalkylate) nonstick coating, like FEP, forms nonporous film by melting flow during baking.PFA has the advantage of higher continuous service temperature of 260℃ and stronger toughness, especially suitable for use in the field of anti-viscosity and chemical resistance at high temperature.

· Teflon ETFE: ETFE is a copolymer of ethylene and tetrafluoroethylene. The resin is the strongest fluoropolymer and can form a highly durable coating with excellent chemical resistance and can work continuously at 150℃.

After coating with teflon, it has the following characteristics:

1, Non-viscosity: almost all materials do not bond with PTFE film.Very thin film also shows good non - adhesion properties.

2, Heat resistance: PTFE coating film has excellent heat and low temperature resistance characteristics.It can withstand high temperature to 300℃ in a short time and can be used continuously between 240℃ and 260℃ in general. It has remarkable thermal stability. It can work at freezing temperature without embrittlement and without melting at high temperature.

3, Sliding: PTFE coating film has a lower friction coefficient.The friction coefficient changes when the load slides, but the value is only between 0.05 and 0.15.

4, Moisture resistance: PTFE coating surface does not stick to water and oil, and it is not easy to stick to solution during production operation. If there is a small amount of dirt, it can be removed simply by wiping.Short downtime, save time and improve work efficiency.

5, Wear resistance: under high load, with excellent wear resistance.Under a certain load, it has the double advantages of wear resistance and non-adhesion.

6. Corrosion resistance: teflon is almost impervious to drugs and can protect parts from any kind of chemical corrosion.

Ptfe is a polymer of tetrafluoroethylene.The abbreviation is PTFE. It's called teflon. It is known as the "king of plastics".The basic structure of ptfe is. - cf2-cf2-cf2-cf2-cf2-cf2-cf2-cf2 - ptfe is widely used in a variety of acid and alkali resistance and organic solvents, it is not toxic to humans, but perfluorooctanoic acid ammonium (PFOA), one of the raw materials used in the production process, is thought to have carcinogenic effects.

Study on ptfe tape as root canal isolation material in oral cavity

PTFE tape, which is commonly used as plumber’s tape is an inorganic, non-fibrous, ribbon like material. The aim of this study was to evaluate PTFE tape as endodontic spacer material and to compare it with commonly used spacer material that is cotton, in primary teeth.;Seventeen children undergoing pulpectomy of lower second primary molar bilaterally were included in the study. 

Cotton and PTFE tape were placed as spacers on each side randomly. Samples were taken from the access cavity at baseline and after seven days to check for microbial leakage. Spacer materials were also checked for microbial contamination.;The results revealed that there was a significant increase in the bacterial colony count after seven days in cotton group. The access cavities were also positive for microbial leakage in the cotton group where the spacers showed positive growth. In PTFE group only two samples showed microbial contamination of spacer and out of two only one sample showed contamination of access cavity along with spacer.;Within the limitations of this study, it can be concluded that PTFE tape performed better than cotton as endodontic spacer material. 

Thus, PTFE tape can be recommended as an endodontic spacer material as an alternative to cotton in primary teeth. 

Introduction of ptfe welding process

Steel lined ptfe equipment is usually made with discharge port, feed port, perspective mirror, etc., but how to successfully apply this kind of pipe port in the complex head intersecting line, of course, our answer is welding, then how to welding?How to control the temperature of ptfe welding?Below we tell one by one.

1, ptfe head pipe mouth production

PTFE pipe welding on sealing head to first of all, we should make PTFE sealing head nozzle, according to the size of the nozzle diameter steel head and according to certain proportion by using powder moulding process manufacturing nozzle, 8 hours of sintered under the 380 plus or minus 5 degrees Celsius, after the completion of the sintering good nozzle with lathe car to the right size, to the congratulations of PTFE tube at this moment you have finished.

2, ptfe head opening

Put the extracted head into the steel head, and use the principle of light transmission to accurately open the head, pay attention to the ptfe head must be consistent with the steel head, or the final equipment is prone to bulge, rupture and other potential hazards.

3, ptfe pipe mouth welding

By the first two steps, we can carry out PTFE welding. Here we know that there are two ways of welding (hot pressure welding and hot air welding). We will explain them one by one.

(1) hot pressure welding

Before hot pressure welding we should know the necessary theoretical knowledge, hot pressure welding is a kind of hot welding, provide sufficient heat and enough pressure.Here, we must ensure that the welding interface temperature must reach 673.15k and the pressure reaches 1-2mpa. Therefore, in order to ensure the welding, we need to make corresponding molds to ensure the successful completion of the thermal pressure welding.When all is done, the FEP film can be welded by pressurizing and heating the interface between the nozzle and the head.

(2) hot air welding

Similarly, ptfe hot air welding is a kind of hot welding, which is much simpler than hot pressure welding and does not require so many molds. After placing the pipe mouth, PFA welding rod and hot air welding gun higher than 713K are used to preheat PFA first and then place it on the welding seam for continuous welding.

Note: whether it's hot pressure welding or hot air welding welding temperature will be higher than the melting point of ptfe, ptfe is possible under the temperature cracking, produces in the process of pyrolysis perfluorinated isobutylene and other poisonous gases, so the welding should be in a ventilation environment, when the condition does not allow such as the four fluorine lining tank welding in production must use the fan air supply air flow assurance and wearing a gas mask to ensure security at the same time.

What is suspended ptfe and dispersed ptfe?

Due to the different polymerization methods of ptfe, there are suspension materials (suspension polymerization) and dispersion materials (dispersion polymerization), namely suspension ptfe, disperse ptfe, the processing methods of the two materials are also different.

Suspended material (suspended polytetrafluoroethylene)

Its main forming method is die pressing method, that is, white powder without a little additive, then die pressing forming, sintering above its melting point temperature, and then through appropriate mechanical processing into products, the representative products for the plate, bar, tube, film four categories.

Dispersion material (ptfe)

PTFE fine powder prepared by dispersion polymerization method is generally referred to as "dispersion".Because of the fibrotic properties of this fine powder, especially at temperatures above 20℃, it is recommended to store, transport and mix the material at 5 ~ 10℃.The forming method of this kind of material is to use an auxiliary agent (usually petroleum ether or gasoline) and powder after mixing in the environment of 24℃ or more for about 24h (complete the crystal phase change) and then forming, with the piston extrusion forming, drying, burning.This processing method is commonly known as paste extrusion, also known as push.

Due to the dispersion of fine powder particle size, divided into several grades of specifications, different specifications have different compression ratio characteristics.Compression ratio of less than 100, generally used to produce raw material and microporous tape;Low compression ratio of less than 500, used to produce medium and large specification products;500 ~ 2000 is medium compression ratio.2000 ~ 4400 is high compression ratio material, this material is suitable for the production of thin wall thin line, can continuously large length and high efficiency production.

Identification method: the main difference is the particle size of the two are not the same.Suspension material is coarse, dispersion material is fine.

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!

­­­

What is expanded tetrafluoroethylene seal tape?

Expanded tetrafluoron sealing belt is made of pure Polytetrafluoroethylene dispersion resin, which is stretched at high temperature through lamination.it has low friction coefficient, good resistance to chemical corrosion and airtightness, and can be used at the temperature of -250℃--+280℃ for the sealing of reaction kettle, steam transmission generator and all kinds of special-shaped cans and drums.

The expanded tetrafluoroethylene sealing tape can be pasted on the flange sealing surface.Flange sealing part under medium and low pressure is an economical and practical sealing material.

The expanded tetrafluoroethylene sealing belt retains the chemical corrosion resistance of ptfe, and at the same time, it has flexibility, compression strength, excellent creep resistance, cold flow resistance and tensile strength.

Production process and application of ptfe film

Ptfe film processing equipment will use a Isostatic Moulding Press Machine, Isostatic Moulding Press Machine production bar, and then sintering, finally using a Skiving Machine for Skiving.

Ptfe films are mainly divided into two types: microporous film and turning film.The biggest difference between the two is the permeability of microporous membrane, which is produced by biaxial stretching.Turning film is cut out of the lathe, it does not breathe.

I do not know about turning film, know that it should be used on the seal more.We're going to talk about microporous membranes.

Polytetrafluoroethylene (ptfe) microporous film is made of polytetrafluoroethylene resin particles, which is expanded and stretched to form a microporous film. It can be divided into the following categories:

1. Air filtration membrane

Polytetrafluoroethylene membranes can be used for atmospheric dust removal, air purification and so on the membrane pore size can be controlled 0.2 um, porosity can reach more than 88%, and the needle felt, mechanism of cloth, non-woven fabric, glass fiber and other filter material with surface phase composite filtering performance of coated fabric, PTFE coated filter material has high peel strength, air volume, uniform pore size distribution, etc.As a dust bag or fold type dust removal filter cartridge installed within the dust removal equipment, will be promptly and efficiently calculated intercept with micron ultra fine dust, dust removal efficiency can reach more than 99.99%, the service life for three years, ventilation rate of up to 3-6 m/min, is currently the world's most advanced air filtration material, all kinds of vacuum cleaners, air filter, air purification equipment, the best choice for high efficiency air filter, etc.

Technical parameters are as follows:

Thickness: 5 um - 15 um

Air permeability: 80-100l /㎡•s

Width: 1800 mm or less

Resistance: pa 80 or less

Efficiency: 99.99%

2. Waterproof and moisture-permeable microporous membrane

Ptfe waterproof moisture permeable microporous membrane is made and approved by a special process the bidirectional tensile membrane surface per square inch can reach billions of a microporous, each pore diameter (0.5 to 0.1 um um) is less than the minimum water molecules in the mist of the minimum value (20 UN um - 100), the diameter greater than the water vapor molecules (0.0004 to 0.0003 um um), the water vapor through the water, and cannot pass, take advantage of the microporous structure can achieve excellent waterproof and moisture permeable function;In addition, because the hole is extremely small and longitudinal irregular bending arrangement, so that the wind can not pass through, and thus has good wind protection and heat preservation characteristics.Since the advent of the membrane through continuous improvement, special treatment on the PTFE film, its fastness and durability greatly improved, after composite with other fabrics, widely used in the greenwood clothing, medical clothing, leisure clothing, fire control, chemical protective, antivirus, flooding operation, such as special protective clothing, outdoor sports clothing, shoes and hats, gloves and other accessories as well as sleeping bags, tents and other materials

Technical parameters are as follows:

Thickness: um 20-50 um

Moisture permeability: 16000g/㎡•24hr

Hydrostatic pressure: 6000mm

Extreme uv resistance: 97 highest

Width: 1700 mm or less

G: 5-10 g/m2

3. teflon bubble point film

It with polytetrafluoroethylene (ptfe) as raw material, after puffing stretch forming a kind of microporous membrane, the membrane with a special process combined with on all kinds of fabric and base material, become a new type of filtration material, the membrane pore size is small, about 0.2 to 0.5 mu m, uniform distribution, porosity, while maintain the air circulation, can filter all of the dust particles, including bacteria, achieve the goal of advanced purification and ventilation, it is widely used in pharmaceutical, biochemical, microelectronics and laboratory consumables, etc.

Technical parameters:

Thickness width bubble point

1600mm ≥1kg/cm2 (5.3m/s 127Pa)

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.

The application of UHMWPE material is introduced

In recent years, UHMWPE has been widely used in board, profile, pipe and other main fields.Market research shows that UHMWPE has become a widely used industrial raw material with its excellent abrasion resistance, which is widely used in coal mining, shipbuilding, floor MATS and other occasions and products. These products need certain processing technology, the use of some equipment: for example, UHMWPE/PTFE tube extrusion machine, Polymer/Teflon bar extrusion machine, molding machine, Polymer PTFE sintering furnace, PTFE Gaskets Press moulding machine, etc. In recent years, China's demand for this product is increasing day by day.

UHMWPE separator is basically used in automobile battery manufacturing industry in developed countries in Europe and America.UHMWPE can also be used for viaduct as underrail spacer. UHMWPE film is based on UHMWPE board, which is a film with a thickness of less than 1 mm after cutting.Ninety percent of UHMWPE's customers are electronics floor mat manufacturers, and up to 95 percent of them are used for mouse floor MATS.There are some differences in the use of UHMWPE fiber between Europe and America and Japan. It is mainly used for body armor and weapons and equipment, accounting for 60% ~ 70% of the total consumption, followed by cables, fishing nets and labor protection supplies.Japan is mainly used for cables, fishing nets and labor protection equipment.

Compared with teflon (teflon) used in traditional mouse pad, UHMWPE film is more wear-resistant, and its self-lubricity is second only to teflon material.Cost, UHMWPE film density is small, according to square conversion UHMWPE film than fluron 50% lower.Therefore, UHMWPE film has gradually replaced teflon as the preferred raw material for floor MATS in OEM factories.

Introduction to ptfe teflon pipes

Ptfe teflon tube extrusion machine is divided into many kinds, exactly say ptfe tube forming process has push and pressure method, extrusion method, hydraulic method, welding method, winding method, etc., which is mainly push and pressure method.Generally dispersed PTFE resin with particle size of 500 microns and apparent density of 0.45g/ml ~ 0.55g/ml is adopted.The small diameter tube chooses the compression quite big resin, the medium and large diameter tube chooses the compression quite small resin.Extruder usually choose 200 and 260 solvent oil.PTFE thermal shrinkage tube, PTFE spiral tube, PTFE steel wire reinforced hydraulic tube and so on can be produced by the secondary processing of PTFE tube.

1.1 common ptfe teflon pipe

Ptfe ordinary tube is made of ptfe dispersion resin at room temperature with organic solvent as extruder, and then through drying and sintering.According to the size of the pipe diameter can be divided into two types of ordinary pipe and micro pipe.Ordinary tube inner diameter > 4mm, micro tube inner diameter ≤4mm.

Typical formula for PTFE tube production:

Dispersed PTFE resin: 100 (weight)

Extruder: 18 ~ 24

Production process:

PTFE, extruder - mixing - pushing - pressing - drying - sintering - cooling - products.

Production process parameters:

Mixing: temperature ≤19 ℃, time 10min ~ 20min, mixed at 25 ℃ ~ 30 ℃ for more than 24h.

Blank: compression rate is about 50mm/ min, pressure is 0 ~ 3MPa.

Pushing pressure: the cavity temperature is 30 ℃ ~ 50 ℃, and the die temperature is 50 ℃ ~ 60 ℃.

Drying: under 210 ℃,2h ~ 3h

Sintering: batch sintering, temperature rise rate of 60 ℃/ h,375 ℃±5 ℃ insulation for 4h.

Continuous sintering, dry area 100 ℃ ~ 250 ℃, preheating area 250 ℃ ~ 330 ℃, sintering area 380 ℃ ~ 420 ℃, cooling area less than 300 ℃.

Main equipment: mixing machine, preforming machine, vertical pushing press, drying and sintering furnace.

USES: as insulation and fluid conduit.

1.2 polytetrafluoroethylene heat-shrinkable tube

PTFE thermal shrinkable tube has the property of being heat-shrinkable, so it can be tightly coated on the surface of other workpieces, making the workpieces resistant to corrosion, electrical insulation and viscosity.Widely used in electrical, chemical, mechanical, printing and other industries.The maximum shrinkage of PTFE shrink tubes is reported to be more than 75%.

It is processed by disperse PTFE resin. The principle is that PTFE is subjected to stress during processing and produces forced high-elastic deformation, which is reversible and freezes at low temperature. If the forced high-elastic deformation is reheated, it will gradually disappear and return to the original state.

Typical formula for PTFE thermal shrinkable tube production:

Disperse PTFE resin 100 (weight)

Extruder 20 ~ 22

Production process:

PTFE resin, extrusion aid → mixing → storage → pre-molding → pushing and pressing → drying → sintering → cooling → heat treatment → blowing → cooling → product.

Production process parameters:

The front part is the same as ordinary PTFE tube.

Heat treatment: the quenching process of the dried and sintered pipes after further full sintering at high temperature, the temperature is 390 ℃±2 ℃, and the coolant is -5 ℃.

Blowing: at 310 ℃ or so, fill the compressed gas below 0198MPa, the blowing rate is 200% ~ 400%.

Main equipment: blowing machine, other PTFE tube and the same.

1.3 ptfe teflon steel wire reinforced hydraulic pipe

The common PTFE pipe will break under the pressure of about 40kg/ cm2. When it is combined with steel wire, the pressure resistance will be greatly improved. The maximum working pressure abroad reaches 700kg/ cm2.The results show that the compressive strength and pulse strength of the hose are related not only to the steel wire strength but also to the weaving Angle.When the braiding Angle is 54°44 "for single-layer braiding, the steel wire does not extend under internal pressure, the length and diameter of the hose do not change, and the pressure resistance is the best.

When used as hose for hydraulic system in aviation industry, in order to prevent electrostatic breakdown of inner tube caused by hydraulic oil flow, trace conductive carbon black should be added in the manufacture of PTFE inner tube.However, it was found that adding carbon black could not completely prevent electrostatic discharge from passing through the tube wall and increase the gap.

In the 1960s, Attas manufactured composite tubes, in which the inner layer of the tubes was a uniform mixture of conductive carbon black and PTFE, and the outer layer of the tubes was pure PTFE.This form of tube body layer has axial conductivity, so it can not only eliminate static electricity, but also prevent seepage.

The process:

Inner resin (including conductive carbon black), outer resin → blank → pushing → drying → cooling → testing → weaving → fitting joints → testing.

PTFE steel wire composite hose is mainly used in aircraft hydraulic system, air conditioning system, fuel system, lubricating oil system.In civil industry, it is suitable for soft connection of hydraulic pressure, steam pressure and steam transportation in rubber, plastic, pharmacy, clothing, shipbuilding, automobile, machine tool, motor, diesel engine and paper making industries.

1.4 ptfe teflon spiral tube

PTFE spiral tube, also known as PTFE flexible hose, has not only all the excellent properties of PTFE, but also flexible properties.At present, there are two kinds of PTFE spiral tube and chemical fiber, stainless steel wire and plastic coated glass fiber woven reinforcement.

It is made of PTFE through secondary processing. The process is that PTFE thin-walled tube continuously rotates forward through a combination mold with a temperature of 270 ℃ ~ 280 ℃ at a certain speed.

It is mainly used for the inlet and outlet pipes of the shock parts such as the soft connection dislocation connection, serpentine pipes, pump engines and so on.Used for shielding cable and protecting cable sleeve of aircraft engine.

PLC control system of Polymer extruder

The PLC control system of extruder has been widely used in many fields such as cemented carbide, pharmaceutical, food processing and mechanical processing. Extrusion technology is widely used because it can obtain products with uniform density in the direction of extension and high production efficiency. Currently on the market for some extrusion machine, such as: Polymer Teflon Rod extruder, PTFE UHMWPE tube extruder,etc. extrusion machine while there are almost one hundred years of history, but with the rapid development of information technology, all kinds of information technology in the layer, especially the detection technology, PLC control technology,microelectronics technology and modern control technology development puts forward new challenge on the extrusion machine. It is very important to study the application of PLC control system because the control system is developed in high efficiency, high speed and high precision.

With the rapid development of manufacturing industry, industrial aluminum profiles have been widely used in various high-tech industries, such as aviation, bullet trains, ships and so on. The forming technology of metal aluminum profile mainly includes extrusion, forging and calendering. According to the extrusion molding process, such as the whole process will use the Polymer Teflon bar extruder, PTFE UHMWPE tube extruder, MouldingMachine, PTFE Gaskets Press Moulding Machine, Cutting Machine, PTFE Skiving Machine, Dry Grinder, cleaning machine, vibration screen, automatic feeding machine. The control system of extruder is emphasized. This set of control system combines PLC, MES and upper computer to realize online intelligent management, visual management, process control, process analysis and product traceability of production process.

Isothermal extrusion speed control is an important method for high efficiency and high quality production in rare metal processing enterprises. Different raw materials (Polymer, PTFE, Teflon, UHMWPE), extruder extruded products are different, such as color, shape, density, etc. According to the characteristics of the treasure titanium 25M extrusion machine equipment, combined with the actual production condition, titanium simulation of isothermal extrusion speed control system, put forward to simulate the isothermal extrusion speed control system architecture and function of system implementation, is developed based on industrial PC + PLC titanium simulation of isothermal extrusion speed control system, using the prediction algorithm to build the extrusion speed prediction model. The system can achieve isothermal extrusion of titanium, shorten the extrusion time, and operate reliably.

Explanation of main test indicators of PTFE products

PTFE products are a special type of plastic, which is quite different from other plastics. According to the industry standard of the Ministry of Light Industry, the PTFE products produced must meet the requirements of the index. Below we list the definitions of the 13 main test indicators for PTFE products for reference.

1. The coefficient of linear expansion indicates the degree of expansion or contraction of the material. It refers to the expansion ratio of the finished polytetrafluoroethylene plastic at a temperature of 1 ° C under a certain pressure, expressed as the coefficient of linear expansion relative to the unit length. This coefficient is one of the important indicators for understanding the degree of change in product size with increasing temperature of PTFE products, expressed in units of 1/°C or 1/K. The coefficient of linear expansion coefficient is α = ΔL / (L * ΔT), where ΔL is the change in the length of the object at the given temperature change ΔT, and L is the initial length. The linear expansion coefficient of PTFE is about 10-12*10-5/°C (ambient temperature 25-250°C), ie (0.01-0.012)%, and the linear expansion coefficient of PTFE is 10~20 times that of iron, which is larger than most plastics. 

2. Thermal conductivity: Also called thermal conductivity, it reflects the thermal conductivity of the material. It is defined as two parallel planes with an area of ​​1 m2 perpendicular to the direction of heat conduction inside the object. If the temperatures of the two planes differ by 1 K, the heat is transferred from one plane to the other in 1 second. The unit is defined as the thermal conductivity of the substance, and its unit is watt·m-1·open-1 (W·m-1·K-1). It is a reference indicator for studying the thermal insulation of target products when designing products.

3. The tensile strain at break is the tensile strain corresponding to the tensile fracture stress when the sample of the polytetrafluoroethylene product is not fractured under the tensile load, and the tensile strain is just when the sample material is plastically shaped. The ratio of the difference between the length to the original length and the original length, expressed as a percentage (%).

4. Tensile strength: In the test of tensile specimens, the critical value of the transition from uniform plastic deformation to local concentrated plastic deformation, characterizing the resistance of the material to the maximum uniform plastic deformation, is also the maximum load carrying capacity of plastic under static tensile conditions ( Maximum tensile stress). The unit is MPa. 

5. Elongation at break: It is the increment of the index from the original unit length (ie the rate of change of length), which is the ratio of the difference between the length of the pull-off and the original length to the original length, expressed as a percentage (%).

6. Electrical strength: A parameter indicating the breakdown of equipment insulation at a certain rated voltage, indicating the degree of insulation of the product withstand voltage. It means that under certain conditions, the ratio of the breakdown voltage to the thickness of the sample to be broken is the electrical strength of the product.

7. Breakdown voltage: The voltage at which the test piece breaks down is the highest voltage before being penetrated. That is, the sample does not break down at this voltage. The breakdown is usually caused by a partial discharge in the gas or liquid medium surrounding the sample and the electrode, and the sample at the edge of the smaller electrode (or equal-diameter two electrodes) is destroyed.

8. Density The ratio of the mass of a substance to its volume, that is, the mass of a substance per unit volume, is called the density of this substance. Kilograms/meter 3 or 1 gram per cubic centimeter 1.0 x 103 kg/m3 of polytetrafluoroethylene plastic products are usually tested by dipping, liquid pycnometer and titration.

9. Withstand voltage is the sample between the electrodes, the power frequency AC voltage rises to the voltage before the breakdown is the withstand voltage of the sample.

10. Fracture Nominal strain refers to the tensile strain corresponding to the fracture stress when the tensile specimen is not yielded and the fracture specimen is subjected to the specified specimen size, and the % is expressed by a dimensionless ratio or percentage.

11. The longitudinal dimensional change rate means that the pipe (100 ± 1) with a certain length is placed in a (260 ± 2 ° C) oven for 3 hours, and taken out at a normal temperature of 23 ± 2 ° C for 4 hours. The length of the treated sample is The percentage of the difference between the original size and the original size.

12. Dielectric strength is a measure of the electrical strength of a material as an insulator. It is defined as the maximum voltage per unit thickness that a unit is subjected to when it is broken down, in volts per unit thickness. The ratio of breakdown voltage to sample thickness. The breakdown voltage is tested according to GB/T1408.1-2006. The dielectric strength is in kilovolts per millimeter (KV/mm).