Ftoroplast: technical specifications, GOST

Fluorine plastic is a synthetic polymer material widely used in the chemical, electrical and food industries mainly as coatings. Its advantages include, first of all, the possibility of using in a wide range of temperatures and a low coefficient of friction.

Definition and types

Fluoroplastics are several types of fluorine-containing plastics. Most often, polytetrafluoroethylene is used in industry and everyday life. Depending on the manufacturer, this material may have different names. Imported polytetrafluoroethylene is also sold in specialized stores in Russia. Material made in the USA is called Teflo, in England it is Fluon, and in Germany Gostaflon. In Russia, it is known as ftoroplast-4.

Other varieties of this material are not widespread, but are also quite popular. It:

• Polytrifluorochlorethylene (fluoroplast-3);
• Polyvinylidene fluoride (fluoroplast-2);
• Other copolymers of fluorine derivatives of ethylene.

Preparation method

Get all these varieties chemically. In fact, they are polymers to which fluorine atoms are added. Hence their name.

Ftoroplast-4 is synthesized in the form of a white powder, and then pressed and sintered at high temperature. Other grades of this material are usually obtained by quenching.

In the manufacture of many innovative, modern products, fluoroplastic is used. The specifications are really just awesome. The advantages of this material include:

• High chemical resistance. Ftoroplast-4 does not dissolve even when boiled in aqua regia.
• Inertness and low porosity.
• Very low coefficient of friction. This indicator in fluoroplastic remains almost unchanged at any temperature.
• Excellent dielectric properties. This material remains an insulator even at a temperature of 200 gr.
• Stability. The chemical properties of fluoroplast-4 do not change at temperatures up to -300 gr.
• Fire resistance is another advantage of a material such as fluoroplastic. Characteristics (heat-resistant polymer is characterized by self-extinguishing ability) it can be used in places with high fire hazard.
• Gas tightness.
• Biological compatibility. This type of plastic is often used to make dentures.

PTFE disadvantages

As you can see, the material is very high quality and almost universal - fluoroplastic. The characteristics he has are just wonderful. However, of course, he has some disadvantages. These include:

• High cold flow. This property somewhat limits the use of fluoroplastic in electronics.
• The ability to release harmful substances when heated above +300 gr.
• The weight is large in comparison with other polymers and the wear resistance is not too good.

Where is used

Ftoroplast is used in many areas of the national economy. Very often it is used:

• In the automotive industry. Since the friction coefficient of this material is very small, high-quality bearings, friction units, support racks, etc. are obtained from it.
• In the electrical industry and electronics. The PTFE insulator is also just great. Therefore, it is very often used in the manufacture of cables, circuit boards, radio components, etc.
• In medicine. In addition to prostheses and implants, fluoroplast makes containers for storing serum and plasma. Made from it and packaging for drugs.
• In the food industry. This material is very well suited, for example, for the manufacture of dough rolls used at bakeries, milk filling pumps, etc. Teflon on the inner surface of pans is also one of the varieties of fluoroplastic.
• When assembling water pipes and sewer systems (FUM tapes).

Thus, the material is very popular, and in some cases simply irreplaceable - fluoroplastic. Characteristics (its applicability is actually very wide), provided by GOST, we will consider a little below.

Coefficient of friction

This indicator in PTFE is very small. The kinetic and static coefficient of friction for steel is only 0.04. However, as already mentioned, ftoroplast - the material is not too wear-resistant. Therefore, after 100 passes, the properties of its surface change. In this case, the static coefficient of friction increases to 0.13, and the kinetic coefficient increases to 0.08.

The fluoroplastic surface undergoes irreversible changes even at a very high sliding speed. In this case, the coefficient of friction increases by 2-3 times. Moreover, the value of this indicator can vary greatly from temperature fluctuations.

The coefficient of friction of the fluoroplastic can decrease with increasing load. So, for example, at a pressure:

• in 20-30 kg / m ^{2 the} value of this indicator is 0.1;
• in 150-300 kg / m ² - 0.02.

The material is quite soft - ftoroplast. Its characteristics are such that when used for manufacturing, for example, bearings, it is necessary to add powdered fillers to it. It can be coke, fiberglass, molybdenum disulfate, etc.

Optical properties

In thin films, fluoroplastic freely transmits light, that is, it is transparent. It looks about the same as polyethylene. In thick films, this material is visible.

The fluoroplastic transparency index for UV rays, depending on the variety, is 2000-4000 A, for infrared rays in the wavelength range from 2 to 7.5 μ.

Exposure to high temperatures

When the fluoroplastic is heated above 327 degrees, its crystals are destroyed, as a result of which it becomes an amorphous form. In the normal state, thick parts made of this material are opaque. After the transition to the amorphous form, the fluoroplastic begins to freely transmit light. In this case, the material remains not viscous, but highly elastic. When heated to 415 degrees C and above, the process of its decomposition begins. That is, fluoroplastic does not have viscous flow at any temperature.

This affects the technology of the process of manufacturing parts from it. Fluoroplastic (GOST defines technical specifications with maximum accuracy) cannot be used for processing according to traditional methods for plastics. For example, it is impossible to make a product from it by injection molding or by extrusion. Parts and assemblies are made of this material by sintering technology using “tablets” compressed at low temperatures.

Chemical properties

Ftoroplast-4 is a chemically stable substance. This material does not dissolve even in very aggressive substances - dilute and strong acids. Concentrated alkaline solutions have no effect on it.

The only thing he does not tolerate contact with is solutions of alkali metals in ammonia, as well as elemental fluorine and chlorine trifluoride. The effect of these chemicals at elevated temperatures is manifested .

Expansion coefficient

According to this parameter, the fluoroplastic F4 characteristics also have simply excellent. However, its expansion coefficient varies with temperature. How exactly is shown in the table.

Recrystallization

As already mentioned, one of the drawbacks of fluoroplastic (the technical characteristics of which are generally good) is a rather high degree of cold fluidity. In practice, this is expressed in a change in the shape of products made from it at high pressure. If they are used at not too high temperatures - from +80 to +100 degrees C, the load on them should not be more than 10 kg / m ² . With greater pressure, noticeable deformations will remain on the product. With increasing temperature, the load should also decrease.

At strong pressure (100-200 kg / m ² ), a sample made of fluoroplastic can be crushed into a plate with a decrease in thickness by 3-5 times depending on the temperature. During deformation of this material, cracking usually does not occur and no other damage occurs.

In the table below, you can see what technical characteristics of fluoroplastic have in this regard (compression at certain loads).

You can use photoplastic for the manufacture of parts used at more than 30 kg / m ² pressure. However, in this case, the design of the interface nodes in the product should be as dense as possible. The presence of cavities or significant gaps in it is not allowed. In this case, the fluoroplastic will simply have nowhere to leak. Fluoroplast material is not too elastic. Therefore, in order to achieve a snug fit, rubber is added to it during production. Sometimes in the nodes of adjacency also use special spring compensators.

Ftoroplast: specifications

In the production of fluoroplast-4, the requirements of GOST 10007-80 are mandatory. The table below shows the most significant physicochemical properties of this material.

Fluoroplast-4 has such remarkable characteristics. The properties of this material allow it to be used for the manufacture of parts of the highest quality.

Fluoroplast-4 brands

As already mentioned, polytetrafluoroethylene is the most popular type of polymer of this type. At the moment, several brands of fluoroplast-4 are produced:

• F-4PN. Used for the manufacture of products of high reliability.
• F-4O. It is used in the manufacture of general purpose products.
• F-4D. Thin-walled tubes, cable insulation, hoses and FUM tapes are made of fluoroplastic of this brand.
• F-4D. A very technologically advanced material used to make products of exact size.

PTFE sheet

Products of this type are very popular in modern industry. For the production of electrical insulating, anti-friction and cushioning products, a polymer such as fluoroplastic has very good technical characteristics. Its sheet version according to manufacturing technology is classified into:

• material of brand "C" (planed);
• brand “P” (pressed).

Such a fluoroplastic is sold in rolls without a coil. Its thickness is also determined by GOST and, depending on the width, it can be 2-4 mm.

Fluorine plastic, the technical characteristics of which are simply excellent, is a modern material used for the manufacture of a wide variety of units and parts. In comparison with ordinary plastic, it has a lot of undeniable advantages. Both the fluoroplastic and its products, due to the increased quality requirements, must be manufactured in strict accordance with GOST.