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)