Materials, Finishes & Treatments

Customizing Your Equipment

Finishes & Surface Treatments Tailored to Your Needs

Understanding the operating temperature range and chemical resistance of the filtration media is critical for selecting the proper fabric for your filtration needs. Filter Holdings offers innovative design construction and finishes for effective filtration.

Filter Holdings has been at the forefront of fabric application with our Unipore expanded PTFE (Teflon) membrane for all types of filtration. The Unipore membrane offers fine uniform pores on the fabric surface that extends the filtration range to submicron levels. The PTFE surface repels water, water-borne acids, alkalis, and oils while providing exceptional release.

Take a closer look at finishes & treatments

Depending on the application, process temperature and the particle size, Filter Holdings offers a fabric finish tailored to the customer's needs. We offer a variety of finishes, each designed to match fabric characteristics.

Standard finishes for felted fabrics
Standard finishes for fiberglass fabrics
Standard finishes for woven fabrics
Our proprietary surface release coating (SRC) and MaxClad II for felts
Our proprietary Unipore expanded PTFE membrane for felted or woven fabrics

Our innovative filter fabric surface treatments were developed to provide superior performance over non-treated fabrics.

When applied to the surface of a high quality fabric, our advanced fabric surface treatments offer exceptional release, abrasion resistance, water resistance, protection from acids, alkali or other degrading chemicals and effective filtration of sub-micron or oily particles during processing.

Surface Release Coating (SRC)

Close up microscopic view of Surface Release Coating

Surface Release Coating (SRC)

Surface Release Coating (SRC) treatment was developed for applications where particle release from ordinary fabrics is a major problem. SRC alters the surface into a smooth resilient skin that does not allow particles to stick or to penetrate and/or blind the felt. Abrasion resistance is an added benefit.

MaxClad II Spanning Between Fibers

MaxClad II spanning between fibers

MaxClad II is a proprietary treatment that produces a smooth microporous interlayer of Teflon over the surface of the felt, repelling water borne chemicals and imparting abrasion resistance. More importantly, MaxClad II treatment produces exceptionally fine pore sizes that improve filtration efficiency. The Teflon structure reaches deep into the felt to protect against acids, alkali or other degrading chemicals.

Unipore Surface

Unipore surface

Filter Holdings has been at the forefront of applying fabrics with its Unipore ePTFE (Teflon) membrane to solve the most difficult filtration problems. The Unipore membrane provides fine uniform pores on the fabric surface that extends the filtration range down to submicron levels. The ePTFE surface repels water, water borne acids and alkali as well as oils while providing exceptional release.

The Unipore membrane offers a high flow structure with no sacrifice in submicron retention. Using heavy duty premium substrates ensures a long service life in harshest conditions.

The Unipore line is available in a wide range of woven or felted filter fabrics.

Standard Felt Aramid Fiber

Standard Felt Aramid Fiber

Aramids (Nomex, Conex, etc.) have long been considered the most cost-effective filter media options for high temperature operations as long as the temperature does not exceed 400°F and acids or strong alkali are not present. Felted Aramids are the prime choice for pulse jet baghouses used in asphalt, cement, utility or incineration operations around the world.

However, standard Nomex felts can only filter down to a nominal 2 micron range and can be severely degraded by sulfuric or hydrochloric acids. Filter Holdings offers a wide variety of finishes including all-PTFE membranes to their surfaces. The membrane shields the fabric from penetration by water-borne chemicals and can filter out particles down to submicron levels. The Unipore treatment is also available applied to Aramids with acid resistant treatment as a second layer of protection.

In applications where surface abrasion by the incoming dust is not a problem, Filter Holding's line of Aramid felts with Unipore offer the optimum combination of high temperature resistance and fine filtration capability.

Chemical Resistance

Standard Or Static Conductive Fabrics & Finishes

Filter Holdings offers both standard and static options. Each has specific benefits depending on the media being filtered. We are proud to offer a range of finishes to ensure the best quality of filtration possible.

Standard Finishes For Felted Fabrics

Standard finishes for Felted Fabrics

Felted fabrics perform best when coated with a finish. Finishes provide durability and an increase in functionality. Filter Holdings offers a variety of finishes that respond effectively to unique filtration requirements. The table below describes the different functions of finishes for felted fabrics. Our experts can work with you to ensure your felted fabric filter bags are coated with the proper finishes for the media you are filtering.

FINISH	FEATURES
Singe	Removes surface fiber for better release
Glaze	Melts the surface fibers to a smooth finish
Singe/Glaze	Combination of singe/glaze techniques for a glossy finish
Acid Resistant	Protects fibers against acid hydrolysis
Oleophobic	Repels water and water borne chemicals
ePTFE (Teflon) Impregnation	Enhanced dust release combined with acid protection and repellency

FINISH	FEATURES
Singe	Removes surface fiber for better release
Glaze	Melts the surface fibers to a smooth finish
Singe/Glaze	Combination of singe/glaze techniques for a glossy finish
Acid Resistant	Protects fibers against acid hydrolysis
Oleophobic	Repels water and water borne chemicals
ePTFE (Teflon) Impregnation	Enhanced dust release combined with acid protection and repellency

Standard Finishes For Fiberglass Fabric

Standard finishes for fiberglass fabric

Fiberglass yarns are fragile and require a finish that allows the yarns to move under use without abrading each other. Filter Holdings offers its fiberglass filter bags with a choice of three finishes:

10% (Min) PTFE
This is a premium finish that provides outstanding lubrication for fiber movement. The PTFE finish provides a slick surface for dust release and protection against attack by water borne acids and chemicals. It is the most asked for finish for pulse jet use.
Acid Resistant
This finish provides resistance to water borne acids using lower cost ingredients. It is used in pulse jets as well as reverse air baghouses.
Silicone/Graphite/Teflon (SGT)
This low cost finish is mostly used in reverse air baghouses. It is a light duty finish used when fabric movement is minimal.

Static Conductive Felt

Static Conductive Felt

Passage of a dust stream past a fabric will create a charge that may stay and possibly increase. It will eventually spark to the surrounding area causing a fire or explosion. Subsequently, static conductive fabrics have found widespread use in processing combustible powder such as starches, proteins, sugars or cocoa.

With advances in technology, equipment and particle size control, the pharmaceutical, food and chemical industries have asked for additional features in static conductive fabrics such as fine particle retention, easy release and resistance to chemicals.

In response, Filter Holdings has applied its Unipore membrane to premium felts with a stainless steel matrix for conductivity. This innovative product is static conductive, can filter out sub-micron particles, and offers superior particle release and water and chemical resistance. These properties are unmatched by any other filtration fabric.

Static Conductive Woven Fabrics

Static Conductive Woven Fabrics

Pharmaceutical, Food and Chemical industries have long recognized the inherent dangers of using non-conductive fabrics for processing powders such as starches, proteins such as sugar or cocoa. For over 60 years, Filter Holdings has supplied these industries with static conductive fabrics and has continued to develop innovative new fabrics.

The widespread acceptance of conductive fabrics has led to demand for variations with features such as better release, chemical resistance or submicron filtration while retaining the outstanding discharge properties.

The Unipore surface treatment enhances all of the above properties. Its 100% Teflon surface is designed to retain all particles on its surface down to submicron size, and prevent penetration and blinding. Its slick surface releases particles quickly and its water and oil repellency prevents chemicals from coming into contact with the underlying fabric.

Applied to multifilament woven fabric with stainless steel or carbon fibers, it offers unmatched safety and efficiency in an FDA compliant package.

Permashield Precoat Powder

Permashield precoat powder

Coating the filter bags with a specifically engineered precoat powder is an inexpensive step for protecting them from blinding on start-up-and extending their service life. Upsets during start-up cause damage to the bags that manifests itself months later.

Permashield Powder has a tightly controlled particle size for maximum protection. It covers the bag surface with a porous interlocked layer that helps prevent fine particles or product aerosols from reaching the fabric matrix. Permashield Powder remains as a protective layer on the bag long after start-up and continues to add protection to the bag from blinding or attack by chemicals.

Permashield Powder is accompanied with instructions for application and troubleshooting, including recommended usage for different size baghouses as well as a step by step application guide.

Microfiber, Microdenier Fabrics

Filter Fabrics and Materials

Material Characteristics

Filter Holdings range of standard filter media includes:

Nomex: Available in weights from 14 to 18 oz. Nomex is a cost-effective solution for temperatures up to 400°F continuous.
PPS (Procon, Torcon): At oxygen levels up to 15% and below 375°F, PPS is the fabric of choice when acids or alkali are present.
P-84: The unique trilobal fiber structure makes P-84 a highly efficient filter fabric at temperatures up to 465°F.
Fiberglass: Available as woven or felted, in weights from 10 to 27 ounces, fiberglass can handle continuous temperatures to 550°F.
PTFE (Teflon): The ultimate fabric at a cost, good to 550°F continuous, in felts or wovens and with UNIPORE membrane

FIBER	RESISTANCE TO ACIDS	RESISTANCE TO ALKALI	RESISTANCE TO FREE RADICALS (includes oxygen, ozone, bleach, etc.)	MAX CONTINUOUS OPERATING TEMP °F
POLYESTER (Dacron)	Good	Fair	Excellent	275°
POLYPROPYLENE	Excellent	Excellent	Poor	190°
NYLON	Fair	Excellent	Excellent	190°
HOMOPOLYMER ACRYLIC	Excellent	Fair	Good	265°
NOMEX®	Fair	Excellent	Good	400°
FIBERGLASS	Excellent	Fair	Good	500°
PPS (Ryton®, PROCON®)	Excellent	Excellent	Poor	375°
POLYMIDE (P-84)	Good	Good	Good	430°
PTFE (Teflon®)	Excellent	Excellent	Excellent	500°
COTTON	Poor	Excellent	Good	180°

POLYESTER (Dacron)

Resistance to Acids - Good

Resistance to Alkali - Fair

Resistance To Free Radicals - Excellent
(includes oxygen, ozone, bleach, etc.)

Max Continuous Operating Temp °F - 275°

POLYPROPYLENE

Resistance to Acids - Excellent

Resistance to Alkali - Excellent

Resistance To Free Radicals - Poor
(includes oxygen, ozone, bleach, etc.)

Max Continuous Operating Temp °F - 190°

NYLON

Resistance to Acids - Fair

Resistance to Alkali - Excellent

Resistance To Free Radicals - Excellent
(includes oxygen, ozone, bleach, etc.)

Max Continuous Operating Temp °F - 190°

HOMOPOLYMER ACRYLIC (Draylon T)

Resistance to Acids - Excellent

Resistance to Alkali - Fair

Resistance To Free Radicals - Good
(includes oxygen, ozone, bleach, etc.)

Max Continuous Operating Temp °F - 265°

NOMEX®

Resistance to Acids - Fair

Resistance to Alkali - Excellent

Resistance To Free Radicals - Good
(includes oxygen, ozone, bleach, etc.)

Max Continuous Operating Temp °F - 400°

FIBERGLASS

Resistance to Acids - Excellent

Resistance to Alkali - Fair

Resistance To Free Radicals - Good
(includes oxygen, ozone, bleach, etc.)

Max Continuous Operating Temp °F - 500°

PPS (Ryton®, PROCON®)

Resistance to Acids - Excellent

Resistance to Alkali - Excellent

Resistance To Free Radicals - Poor
(includes oxygen, ozone, bleach, etc.)

Max Continuous Operating Temp °F - 375°

POLYMIDE (P-84)

Resistance to Acids - Good

Resistance to Alkali - Good

Resistance To Free Radicals - Good
(includes oxygen, ozone, bleach, etc.)

Max Continuous Operating Temp °F - 430°

PTFE (Teflon®)

Resistance to Acids - Excellent

Resistance to Alkali - Excellent

Resistance To Free Radicals - Excellent
(includes oxygen, ozone, bleach, etc.)

Max Continuous Operating Temp °F - 500°

COTTON

Resistance to Acids - Poor

Resistance to Alkali - Excellent

Resistance To Free Radicals - Good
(includes oxygen, ozone, bleach, etc.)

Max Continuous Operating Temp °F - 180°

Solutions For Any Filtration Challenge.

Premium industrial filtration solutions for air, gas and liquid filtration.

SEE OUR INDUSTRIES

Materials, Finishes & Treatments

Finishes & Surface Treatments Tailored to Your Needs

Take a closer look at finishes & treatments

Surface Release Coating (SRC)

MaxClad II spanning between fibers

Unipore surface

Standard Felt Aramid Fiber

Chemical Resistance

Standard Or Static Conductive Fabrics & Finishes

Standard finishes for Felted Fabrics

Standard finishes for fiberglass fabric

Static Conductive Felt

Static Conductive Woven Fabrics

Permashield precoat powder

Microfiber, Microdenier Fabrics

Filter Fabrics and Materials

Material Characteristics

POLYESTER (Dacron)

POLYPROPYLENE

NYLON

HOMOPOLYMER ACRYLIC (Draylon T)

NOMEX®

FIBERGLASS

PPS (Ryton®, PROCON®)

POLYMIDE (P-84)

PTFE (Teflon®)

COTTON

Solutions For Any Filtration Challenge.

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