PTFE Filter Bags

Commonly known as Teflon® filter bags, which are made from PTFE, short for polytetrafluoroethylene. PTFE is a high-performance synthetic polymer with unique properties. In addition to being hydrophobic, which means it repels water, PTFE is known for its chemical resistance, non-stickiness, high-temperature tolerance, and low friction coefficient. These properties make PTFE filter bags ideal for a wide range of filtration applications. As a filter media, it has the following characteristics:
High Filtration Efficiency – The microscopic pores in the PTFE material provide a large surface area for effective particle capture, even for particles as small as submicron size. This enables the bags to achieve high filtration efficiencies, often exceeding 99% or more, which is crucial in applications where strict air quality regulations are in place.

Chemically Inert – PTFE materials have a high resistance to many corrosive chemicals, making them suitable for filtration applications involving aggressive gases. This chemical resistance ensures longer bag life and reduces the risk of bag failure or degradation.
Excellent Thermal Stability – PTFE materials can withstand extreme temperatures without sacrificing filtration performance. The continuous operating temperature of Teflon filter bags is 240°C (464°F), which makes them well-suited for use in applications involving high-temperature gases, such as those found in industrial furnaces or incinerators.
Low Friction Coefficient – PTFE filter bags also offer excellent dust cake release properties. The low surface energy of PTFE prevents dust particles from sticking to the bag’s surface, facilitating easier cleaning and reducing the frequency of bag replacements. This characteristic helps maintain consistent filtration performance and reduces maintenance costs.
Excellent Hydrolysis Resistance – PTFE is known for its water-repelling characteristics, making it an ideal material for applications where moisture is a concern.
Excellent Oxidation Resistance – PTFE is highly resistant to oxidation, which ensures the longevity and durability of the filter bags in high moist heat environments.

In addition to these filtration characteristics, PTFE filter bags also offer a number of other advantages, such as:
Long Service Life – PTFE filter bags have a long service life, even in challenging operating conditions. This can lead to significant cost savings over time.
Easy to Clean and Maintain – PTFE filter bags are easy to clean and maintain, which helps to reduce downtime and improve productivity.
Lower Energy Consumption – Because of Teflon filter bags’ enhanced cleaning efficiency, it helps to reduce the overall pressure drop across the filter media, improving the efficiency and energy consumption of the dust collection system.

Dust Collection Characteristics

Unique properties of PTFE filter bags include nonreactivity, hydrophobicity, a low coefficient of friction, and good insulating properties.

Advantage

Excellent acid, alkali, hydrolysis, high temperature and oxidation resistance. Long-lasting service life, and lower operating costs.

Disadvantages

Very expensive. Poor flex abrasion qualities and requires a 20 vertical wire minimum supporting cage.

Industry & Application

Chemical Industry, Cement Industry, Coal Boiler, Garbage and Sludge Incineration, Renewable Energy Industry

Construction & Treatment

PTFE filter media can be constructed and treated with various options so that they become best suited for various operating conditions, applications, and industries.

Filter Media Construction

Needle Felting

Needle felting is a traditional non-woven fabrication process by punching a fiber batt into itself to hook and entangle fibers which then form a thin, relatively dense structure, either with or without a light woven support scrim. Needlefelt filter media have smooth surfaces and offer good depth filtration and particle capture.

Filter Media Treatment

ePTFE Membrane
Adding an ePTFE membrane to a PTFE filter bag allows the membrane to act as the filter cake. Dust stays on the surface of the membrane and does not get entrained into the fibers of the filter bag, which lengthens the filter bag life. It also reduces wear and tear, lower maintenance costs, and energy costs due to easy dust cake release during the cleaning cycle.

PTFE Coating

The filter media is coated in a bath or spray of liquid PTFE resin. This is done to protect filter bags. The treatment improves the flex life, heat and chemical resistance, and dust release from the filter bags. This increases the service life and filtration efficiency. PTFE finish is commonly used in applications with corrosive chemical compounds, sticky dust, or high moisture contents.

Static Resistant

Helps to ground the filter bag to eliminate sparks which might cause combustion explosions.

Glazing

Glazing, also known as calendering, is the high-pressure pressing of the fabric by rollers to flatten or smooth the surface. Glazing pushes the surface fibers down onto the body of the filter media to increase and uniform surface life, improve stability, reduce shrinkage, and improve dust cake release.