Nonwoven fabrics are broadly defined as sheet or web structures bonded together by entangling fiber or filaments (and by perforating films) mechanically, thermally, or chemically. They are flat, porous sheets that are made directly from separate fibers or from molten plastic or plastic film. Nonwovens are not made by weaving or knitting and do not require converting the fibers to yarn.
The term ‘composite nonwovens’ refers to a category of materials different from ‘nonwoven composites,’ which consist of a resinous matrix reinforced by an embedded non-woven fabric. Composite nonwovens are created by a modern and innovative industry employing non-woven technologies to bring together fibers of different origins, different characteristics or a combination thereof.
Combinations of different nonwoven preforms are prepared either by employing a variety of process technologies or by combining nonwoven preforms with traditional textile preforms into a consolidated structure. This can also result in the creation of composite nonwovens. Composite nonwovens can provide an engineered solution by creating multi-functional products, They also provide an economical solution by eliminating manufacturing processes and replacing two or more products with one.
Sunstrand’s natural raw fibers are available for feedstock in nonwoven product lines. These fibers can be supplied by Sunstrand and blended by customers for their specific needs. These fibers can be blended with other thermoplastic polymer fiber such as polypropylene or polyesters to form nonwoven mats, or formed into chopped strand mats to be used in thermoset infusion processes. The resulting composite is lightweight, high strength and cost competitive. The inherent properties of the natural fibers provide acoustic absorption and vibration reduction. Typical cut lengths are 1½” – 4.”
Natural fiber Chopped Strand Mats (CSM) are great for cosmetic layers in laminate composites or anywhere transverse isotropy is useful. CSM is typically supplied in a fabric-like roll form where the fibers are randomly oriented and held together with a resin specific binder. CSM is usually used in laminate composites with thermoset resin systems in applications such as boats, wind turbine blades, and molds. Formation densities and areal weights can be easily customized to manufacturer specifications. Sunstrand’s CSM architecture is compatible with Sheet Molding Compound (SMC), a high volume, rapid thermoset polymer manufacturing technique used in large plastic parts such as automobile cargo mats, lunch trays, agriculture and heavy-duty truck body panels.