Needlepunched nonwoven with centrally-located binder
AssigneeDZS Inc.
InventorDimitri Peter Zafiroglu
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Abstract
The present invention concerns a process for forming a wearable and functional fabric from a composite material comprising a nonwoven face layer containing a plurality of fibers, and at least one thermoplastic binder layer disposed underneath. The fibers are initially arranged in a generally planar web and subsequently needlepunched through at least one binder layer. The fiber layers can also be placed on both sides of one or more centrally-located binder layers, and further reinforced with scrims. In an innovative aspect of the invention, the composite is heated under low and uniform pressure to remove thermal stresses, resulting in at a least one relatively smooth face that can be coated to form a wearable fabric, e.g., artificial leather, odor absorbing fabric, and the like.
Claims29
A process of forming a wearable and functional fabric comprising the steps of:
- a. fabricating a precursor fabric by a process comprising the steps of:
- (i) providing a composite comprising at least one web of staple fibers, and at least one thermoplastic binder layer, wherein the melting point of each thermoplastic binder layer is lower than the melting point of the staple fibers, and wherein the composite comprises an upper and lower surface;
- (ii) needlepunching the staple fibers from at least one web of staple fibers into and through at least one thermoplastic binder layer, wherein ends of fibers originating from the needle-entrance side substantially cover the opposite needle exit-side, and wherein the density of needlepunching penetrations is greater than about 40 penetrations per cm2;
- (iii) restraining the composite between two smooth surfaces of an apparatus, which are positioned to apply uniform pressure under about 50 psi throughout the upper and lower surfaces;
- and
- (iv) heating the composite, while continuing to restrain the composite, for a finite time period to remove the thermal stresses in the composite, wherein each thermoplastic binder layer is fully melted and the staple fibers are not melted, deformed or decomposed, wherein all molten thermoplastic is confined to a thickness smaller than or equal to about one-third of the thickness of the whole composite, and wherein the molten thermoplastic does not extend into either the upper surface or lower surface;
- and
- b. providing the precursor fabric with at least one finishing substance to improve the wearability and functionality of the precursor fabric.
Dependencies are inferred from the claim text.