Category: Production Process

How to Judge the Quality of Teflon Mesh Belt?
How to judge the quality of Teflon mesh belt from the senses?

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There are many kinds of Teflon mesh belt in the market, but the qualities are mixed, since the differences between different fiberglass meshes the factories used, production technologies and market concepts.

We can visually identify the amount of impregnated Teflon emulsion from the degree of surface smoothness. If no gloss shows, this mesh belt uses less emulsion in order to save costs. On the one hand, the amount of emulsion affects the price. On the other hand it affects the service life of the mesh belt.

From the sense of touch, you can hold the sample and fold it at a 30-degree angle. If there is obvious crease after folding 3-5 times, it means that the curvature of mesh belt is not enough. The length of Teflon meshes is generally dozens of meters. If the sample breaks for a little bit folds, it must not be used on the machine. Conversely, if you fold more than 5 times and it maintains the original hardness and curvature, this mesh belt is qualified.

This material is commonly known as Teflon. And its formal name is polytetrafluoroethylene (abbreviated as Teflon, PTFE，and F4), that also known as the “Plastic King”. It is polymerized by tetrafluoroethylene, and its structural formulas is -[-CF2-CF2-]n-.

High Temperature Resistance——its operating temperature up to 250℃, and can be used long-term in 200~260℃.
Low Temperature Resistance——it has good mechanical toughness, which can maintain a 5% elongation even if the temperature drops to 196℃ ,and it is still soft at-100℃.
Corrosion Resistance——it shows inert to most chemicals and solvents, and can resist strong acid, alkali, aqua regia and a variety of organic solvents.
Climate Resistance——it has the best aging life in plastics.
High Lubrication——it has the lowest friction coefficient (0.04) in solid materials, which is smoother than ice.
Non-adhesion——it has the smallest surface tension in a solid material and does not adhere to any substance.
Non-toxic——With physiological inertia, it can used as artificial blood vessels and organs and implanted in body long-term without adverse reactions.
Aging resistance——it has irradiation resistance and low permeability, so it can maintain the surface and performance even if it has exposed to the atmosphere long-term.
Non-flammability——its limited oxygen index is below 90.
Acid and Alkali resistance——it is insoluble in strong acid, strong alkali and organic solvents (including magic acid, i.e. fluorine antimony sulfonic acid).
Antioxidant resistance——it can be resistant to strong oxidizing agents.
Insulation——it has excellent electrical properties, which is the ideal C-class insulation material. For example, the Teflon that is as thick as the newspaper can block 1500V high pressure. Its electrical insulation is not affected by temperature. The dielectric constant and dielectric loss are very low in the wide frequency range, and the breakdown voltage, volume resistivity and arc resistance are relatively high.
Acid-alkaline-it is neutral.

What is PTFE teflon adhesive tape.

PTFE (Teflon) adhesive tape: fiberglass is the base fabric, which is coated with PTFE (Teflon) emulsion and dried to PTFE (Teflon) coated glass fiber cloth; PTFE (Teflon) glass fiber cloth coated with silicone adhesive to PTFE (Teflon)adhesive tape.

PTFE (teflon) adhesive tape is high performance, new composite product. The surface is smooth, with good anti-stick, chemical, high temperature resistance and excellent insulation properties.

The application of PTFE (teflon) adhesive tape

Cladding of various high temperature drums, heating flat plates, stripping workpieces; heat sealing of food, medicine and plastic bags.
The cladding of runners, hoppers, aviation molds and other gaskets can also be applied to the sizing machine drum, thermoplastic demoulding and other industries, it’s reusable and easy to replace.
It is suitable for other surface treatment that requires anti-stick, corrosion and high temperature resistance. Be used in packaging, thermoplastic, composite, sealing and sealing, electrical and electronic industries, etc., where it needs to be adhered to heat-resistant and corrosion-resistant insulation, which can be pasted repeatedly.

The strength of PTFE (Teflon) adhesive tape is high and can be applied to the sizing machine drum, thermoplastic demoulding and other industries, and can be used repeatedly and easily replaced.
It can be directly pasted to various large flat surfaces and regular curved surfaces (such as drums). Without the limit of specialized equipment of spraying PTFE materials, special processes and without the transporttion of professional spray factory for processing. PTFE (Teflon) adhesive tape is excellent option, and the long term working temprature is up to 260℃.

The features of PTFE (Teflon) adhesive tape

1. Good thermal performance (continuous working temperature is above 260℃), the peak temperature can reach 300℃. The tape can be safely used even on overheated heaters;

2. Good adhesion, the slag of the melted packaging film will not stick to the heater.

3. Excellent electric insulativity.

Good stability, durability.

Application of PTFE (Teflon) adhesive tape

1. Heat sealing/cutting machine of food and medicine plastic packaging industry, and high speed heat sealing machine.

2. Anti-adhesive treatment on the surface of drying drums; anti-adhesive treatment on the surface of the laminating machine; anti-adhesive treatment on the surface of the drying drums.

3. Application of anti-adhesive, friction reducing.

The properties of PTFE (Teflon) adhesive tape

1. Weather, anti-aging resistance between low temperature -196℃ and high temperature 300℃.
For example, if it is placed at a high temperature of 250℃ for 200 days, the strength and the weight won’t be reduced. Be placed at 350℃ for 120 hours, the weight will only decrease by about 0.6%; Maintain the original softness at -180℃.

2. Non-stick: The surface is smooth and it is not easy to adhere to any substance. Easy to clean; all adhesive substances, such as paste, resin, paint, etc. can be easily removed.

3. Chemically resistant, which can resistant strong acids, alkalis, aqua regia and various organic solvent.

4. Medicament resistance and non-toxic. Resistant all pharmaceutical items.

5. High insulation performance (permittivity: 2.6, tangent below 0.0025), UV protection, anti-static.

6. Fire retardant.

7. Easy to use and long service life.

The basic film-forming materials for non-stick coatings in the production of Teflon are fluororesins and binders. The choice of fluororesin plays a crucial role in the non-stick properties of Teflon spray non-stick coatings.

There are many types of fluororesin sprayed on Teflon, among many fluororesins, polytetrafluoroethylene (PTFE) has the lowest friction coefficient, so PTFE is the preferred fluororesin for non-stick coatings. For better coating properties or ease of construction, Generally, a resin such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) or tetrafluoroethylene-hexafluoropropylene copolymer (FEP) is added on the basis of PTFE. Therefore, the fluororesin for non-stick coatings is generally a PTFE-based Teflon mixture.

Teflon PTFE has a regular structure, high crystallinity, and is almost insoluble in any solvent under normal temperature conditions; and the melting temperature is high, the melt viscosity is large, the fluidity of the coating is not good, which directly affects the non-stickiness of the Teflon-coated non-stick coating. For the above reasons, the fluororesin used in general non-stick coatings is a mixture of PTFE and other fluororesins, such as FEP, PFA, and the like. Compared with PTFE, FEP has the advantages of better melt flow and lower crystallinity, which results in a lower porosity of the formed coating, which is especially suitable for the hot and humid environment of baked food factories. PFA is very close to the chemical and thermal stability of PTFE, but PFA has higher toughness than PTFE and improves the wear resistance of the coating. The addition of PFA prevents the formation of large crystalline areas on the surface of the coating film.

Usually, adding more than 40% by weight of PFA has a significant effect. However, the miscibility of PTFE and FEP is limited, and a crystallization zone is formed in a portion where each polymer is separated, and a coating film defect sometimes occurs. Large pores and coating film defects are not allowed in a coating for preventing the substrate from being permeable to water or gas. These defects are to a large extent related to the composition of the fluoropolymer and may also be related to other ingredients in the coating formulation. The method and conditions of using the coating are also important in controlling the structure of the coating (such as cooling rate). The addition of copolymers such as FEP and PFA contributes to the formation of a coating having a lower degree of amorphousness than pure PTFE due to its low crystallinity. Therefore, the mixing of PTFE with FEP or PFA in Teflon non-stick coatings can improve the impermeability of the coating and prevent the formation of defects such as bubbles or corrosion

First confirm that whether the Teflon tape high temperature data is in line with production requirements, usually require temperature resistance 210℃ to 260℃.

Whether the temperature data of the production line is in the technological requirement range, whether the temperature is too high, check whether the temperature sensor is normal.

Teflon adhesive tape its quality problems. If Teflon tape in the coating production process is strictly in accordance with the pressure-sensitive adhesive baking data for heating and curing, curing time is not enough or too fast coating speed will lead to glue, primer glue, the substrate can not be the three components Combination.

After Teflon tape coated adhesive gluing, semi-finished products should be left standing for 2-3 days before rewinding slitting use, the purpose is to glue the full integration with the substrate, the glue in the natural state completely cured.