Non-woven filter fabrics are used in several industries, from your laundry dryer sheets to house wrap for houses. The possibilities for these types of textiles are endless. Great Lakes has helped pioneer several of these textiles used in filtration and other industries. Our value add is vertical integration. With expertise in non-wovens and other technical textiles, we can source your desired material, or we may have it in stock. We also have the capability to convert to any shape or size roll or die-cut piece. We can also fabricate bags and other parts through sonic welding or industrial sewing at our in-house facility.

Learn about woven filter fabrics.

Contact us today for a quote regarding your non-wovens filter fabrics or textiles.

Fiber Types in Non-Woven Textiles

Non-woven filter fabrics are a textile structure where fibers are layered into a web which is then bound together by bonding and or the interlocking of fibers. Non-woven filter fabrics begin with synthetic or natural fibers, then staple (short blend-able with other types) or continuous (long filaments). Diameter (denier) may differ depending on based polymer and process.

Fiber selection of a non-woven is dependent on many factors. Synthetic fibers are used because they have properties that make them more workable and are more readily available than natural fibers. Bi-component fibers have multiple types of polymers.

Average Fiber Tensile Strength Chart

Fiber	Avg. Tensile Strength (GSM)
Polyethylene	30
Aramid	22
Graphite	20
Nylon	10
Polyester	9
Cotton	4
Rayon	3
Acrylic	2.5
Acetate	1.2

Once fiber is determined, there are four common processes for forming your fibers into the desired non-woven filter fabric. They are formed in three popular ways:

Non-Woven Filter Fabrics & Web Formation

• Dry Laid: The fiber web is formed mechanically or by air.
• Mechanical: The passing of fiber through a card and onto a moving conveyor.
• Parallel: Web: generated by a carding machine aligned with the motion of a moving conveyor system (machine direction)
• Transverse Web: generated by a carding machine aligned perpendicular to a moving conveyor; distribution is accomplished via a cross lapper.
• Cross Laid: a combination of parallel web and transverse web.
• Air Laid: formed by blowing single fibers onto a screen.  The fibers are oriented in a random position rather than parallel or transverse.
• Wet Laid: The fibers are suspended in a liquid and fed onto a conveyor screen, forming a web.  Suction devices under the screen remove the liquid.  The fibers may be oriented in a variety of patterns.
• Spun Bonding: Formed by melting and extruding the polymer through spinnerets.  The extruded filaments are drawn by air onto a conveyor to form a web by subjecting the fibers to heat and pressure, bonding at the fiber cross-over points.

Bonding and Nonwovens

At this point the fibers are oriented but not locked together;  therefore the web has very little strength.  Bonding locks the fibers together and is accomplished by mechanical, chemical or thermal methods.

• Needle Punching: Barbed needles pierce the web entangling the fibers with each other creating a stronger flexible web.
• Stitch Bonding: A stitching process is introduced into the web in the machine direction and also imparts stability to the cross machine direction by restricting fiber movement under load.
• Felting: Made by a combination of mechanical and chemical action, pressure, moisture and heat.
• Hydro Entanglement – The web moves on a perforated metal conveyor while high pressure water jets lock the fibers together.  The pattern of the conveyor gives finish to the non-woven filter fabrics.  Also known as hydro-entangled or spun laced.
• Chemical Bonding: Chemicals can be used to bond the fibers of the web.  It is important that these chemical binders provide good adhesion and also some elasticity to impart softness to the fabric.
• Impregnation: The web is passed through a bath of binder chemical, saturated then squeezed between two rollers and dried.
• Foaming: The web is saturated with a foamed binder.  The foam allows the fibers to interlock with consistency of form, and gives good elasticity.
• Print Bonding: An engraved roller is used to apply the chemical binder.  The web passes under the saturated roller and the fibers are interlocked in the pattern of the roller.
• Spray Bonding: The web is transported on a conveyor under spray nozzles.  A vacuum under the conveyor insures the proper chemical penetration.  The web is then heat or air dried.
• Thermal Bonding: Achieved by the use of low melt point fibers or powders in the web.  These low melt fibers serve as an adhesive when the web is passed through a heater.  Very high strengths can be achieved by this process.

Properties of Felts

• Good resilience
• Good shock absorption
• Easy to shape
• Will not ravel
• Good sound absorption
• Good insulators
• Good tear strength

Properties of Needle-Punched Fabrics dependent upon:

• Arrangement of fibers
• Density and pattern of needles
• Needle-Punch Rate and speed of web
• Size of needles and arrangement of barbs on needle
• Length and characteristics of fiber
• Thickness, evenness and weight

Properties of Bonded Fiber Fabrics dependent upon:

• Length and characteristics of fiber
• Thickness, evenness and weight
• Chemical binder and how applied

Properties of Spun-bonded Fabrics

• Good strength to weight ratio
• “Boardy” or stiff
• Good permeability
• Dependent upon filament fiber

Properties of Stitch Bonded Fabrics

• Good strength to weight ratio
• Good stability
• Porous
• Dependent upon stitch pattern, size of yarn, fiber, fabric density.

Hybrid Fabrics

Hybrid fabrics are those fabrics consisting of combinations of other fabrics.  Examples of hybrid fabrics are tufted carpet, reinforced nonwovens and laminated fabrics.

Properties of these fabrics are dependent upon many factors.

Reinforced Nonwovens

• Nature of reinforcing fabric
• Fiber used
• Type of nonwoven manufacture

Laminated Fabrics

• Nature of backing fabric
• Nature of fabric, foam or film
• Types of materials