PTFE felt filter bag

Product description

PTFE felt filter bag for chemically aggressive liquid filtration

The PTFE Felt Filter Bag is specifically engineered for liquid filtration applications involving highly aggressive chemicals, extreme process conditions and demanding environments up to 260C where other polymer materials are not suitable. Made from polytetrafluoroethylene (PTFE) felt, this filter bag provides exceptional chemical resistance, thermal stability and reliable depth filtration performance.

PTFE felt filter bags are typically selected in industrial applications where solutions contain strong acids, strong alkalis, solvents or chemically aggressive compounds and where other materials would degrade rapidly.

Filtration principle

The PTFE felt filter bag operates using inside to outside depth filtration. Process liquid enters the bag, flows through the felt structure and exits the housing, while particles and contaminants are retained throughout the thickness of the media.

This depth filtration approach provides:

• consistent and predictable particle retention

• high contaminant loading capacity

• stable pressure drop behaviour

• reduced risk of media degradation

All contaminants remain inside the filter bag for efficient and safe disposal during change out.

Material characteristics

Polytetrafluoroethylene (PTFE) felt is an advanced material known for unmatched chemical resistance and thermal stability. It is widely regarded as one of the most chemically inert filter media available for liquid filtration.

Key material characteristics include:

• outstanding resistance to virtually all acids and bases

• excellent compatibility with aggressive solvents

• strong resistance to oxidative environments

• inherent non-wetting properties

• high thermal resistance compared to many polymer felts

PTFE felt does not contain binders, resins, silicones or surface active agents. Its chemically inert nature makes it suitable for processes requiring minimal media interaction.

Temperature performance and limitations

PTFE felt exhibits superior thermal stability compared to many common polymer filter media. In liquid filtration applications this allows:

• operation over a wide temperature range

• resistance to thermal degradation in hot process liquids

• maintenance of mechanical strength under thermal stress

Important selection considerations:

• PTFE’s inert nature may limit mechanical strength compared to some reinforced felts

• Certain high stress or mechanical abrasion environments may require specialised support baskets

Material compatibility should always be confirmed for each specific process condition.

Design and construction

PTFE felt filter bags supplied by Filtra International are manufactured with robust construction techniques to support demanding industrial use.

Typical design features include:

• PTFE felt depth filtration media

• stable felt matrix to resist media breakdown

• precision finished surface to reduce fibre migration

• sealed or bonded seams to prevent bypass

• integrated sealing ring options to ensure secure installation

The sealing ring ensures reliable positioning inside the support basket and minimises unfiltered liquid bypass.

Available micron ratings

PTFE felt filter bags are offered in a broad range of micron ratings to accommodate different filtration duties.

Typical available ratings include:

• 1 micron

• 3 micron

• 5 micron

• 10 micron

• 25 micron

• 50 micron

• 75 micron

• 100 micron

Standard sizes

PTFE felt filter bags are supplied in standard industrial sizes to ensure compatibility with common bag filter housings.

Typical sizes include:

• Size 1

• Size 2

• Size 3

• Size 4
  

Custom sizes can be supplied on request.

Operating limits

Typical operating conditions for PTFE felt filter bags include:

• capable of withstanding high temperature process liquids

• robust operation in chemically aggressive environments

• recommended differential pressure change out based on process conditions

Exact operating limits depend on the specific application and should be confirmed before selection.

Typical applications

PTFE felt filter bags are commonly used in:

• aggressive chemical processing

• acid and solvent filtration

• specialty chemical production

• high purity industrial processes

• pharmaceutical intermediates

• strong alkali solutions

• corrosive liquid streams

Key benefits

• Exceptional chemical resistance

• Wide temperature tolerance

• Reliable depth filtration

• High contaminant capacity

• Chemically inert and non-wettable

• Compatible with standard bag filter housings

Configuration and quotation

PTFE felt filter bags are supplied based on application requirements. Selection parameters include:

• micron rating

• bag size

• operating temperature

• liquid composition

Filtra International provides technical support to ensure correct filter bag selection for demanding filtration applications.