PTFE Can Be Applied in Mechanical Engineering

 

1. Sliding rail

Sliding guide rails are often the installation foundation of metal cutting machine tools, medical equipment and many other systems and devices. The accuracy foundation and positioning foundation are an important part of the machine. In the machine tool manufacturing industry, most of the machine tool guide rail pairs use cast iron-cast iron, cast iron-quenched cast iron, cast iron-quenched steel, etc. However, due to its physical properties, the coefficient of friction between metals is large, it is not wear-resistant, and cannot work under dry friction. It crawls at low speeds and small displacements. This crawling affects machine tools, especially precision machine tools, and affects the feed accuracy and Repeat accuracy. When using filled PTFE guide rails, the low-speed stability of the machine tool is greatly improved.

Because the plastic guide rail has the feature of burying foreign objects, iron filings and sand particles can be embedded in the plastic, avoiding its own abrasion, preventing napping and scratching the metal surface, and can protect the bed guide. PTFE containing bronze powder and other fillers has excellent friction properties. After the transfer film is formed on the metal surface, the friction coefficient is greatly reduced, the load-bearing capacity of the transfer film is greatly improved, and the effective working life is also extended. If matched with a metal machine tool guide, the friction coefficient remains unchanged with the increase of sliding speed. Therefore, this kind of filled PTFE guide rail will not produce crawling phenomenon at low speed and micro feed, and it also has vibration absorption and cushioning properties. The friction coefficient of PTFE guide rail is 0.05 when dry friction, and 0.03 when there is oil lubrication.

No matter whether the machine tool guide has lubricating oil or not, its working movement is the same. When the PTFE guide rail needs to be repaired after it is worn out, the repair work is very labor-saving and can be interchanged, and it is easy to maintain the dimensional accuracy. Especially when the guide rail is damaged and needs to be repaired, it is better to use plastic for partial repair.

2. Friction parts

There are many PTFE friction parts commonly used in mechanical engineering, such as bearings, piston rings and gears. PTFE is an ideal material for piston rings and is widely used in air compressors and water compressors. PTFE piston ring acts as a compression ring to block liquid or gas. It is often used in occasions where lubricants or other harsh conditions cannot be used. If it is severely corrosive and has high safety requirements, it can greatly reduce the wear of the cylinder inner wall and repeated boring. The number of holes prolongs the service life of the cylinder.

Almost all piston rings play a hermetic role in reciprocating motion and start frequently. Therefore, the static friction coefficient is required to be small. Under small load, the static friction coefficient of PTFE is 25% to 75% lower than that of other materials. The larger the load, the more its superiority can be exerted. This has incomparable superiority in light starting and light reciprocating. As a result, it reduces energy consumption, reduces vibration and noise, and helps protect the environment.

At the same time, PTFE can be used as a motion transmission and power transmission component in industries such as textiles, printing and dyeing, paper making and food, which have a wide range of working conditions and a very harsh environment.

3. Seals

The use of PTFE film compounded on the surface of the rubber sealing material can improve the solvent resistance and medium resistance of the rubber seal, and the price is relatively low. It has been used for the sealing requirements of various mechanical occasions. Filled FE sealing material has excellent high and low temperature resistance, and is currently the main substitute for traditional asbestos gasket materials.

Carbon fiber reinforced PTFE sealing material has high strength, high modulus, fatigue resistance, creep resistance, high thermal conductivity, low thermal expansion coefficient and low friction coefficient. These comprehensive properties are unmatched by any kind of sealing material, and it is an ideal advanced sealing material.

4. Anticorrosive parts

Modified PTFE has good chemical stability to acid, alkali, and salt corrosive media. It can replace metal ceramics for anti-corrosion engineering. It is especially suitable for high temperature and strong corrosion situations, such as anti-corrosion equipment, pipelines and pipe fittings in chemical plants. Corrosive friction materials, valves, pumps, heat exchangers, porous plates and filter materials for strong corrosive media, linings and coatings for chemical equipment.