Textiles: manufacturing – Textile product fabrication or treatment – Fiber entangling and interlocking
Reexamination Certificate
2000-07-19
2002-07-02
Vanatta, Amy B. (Department: 3765)
Textiles: manufacturing
Textile product fabrication or treatment
Fiber entangling and interlocking
C156S148000, C442S387000
Reexamination Certificate
active
06412154
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to hydro-dynamically bounded carrier webs, a production and use thereof.
2. Description of the Related Art
Laminated carriers (i.e., composites) manufactured from non-wovens are useful in a number of construction applications such as roofing membranes, bituminized roofing webs, insulation, etc. These carriers include textile fabrics such as non-wovens which have been consolidated, impregnated in a bitumen bath and optionally coated thereafter with bitumen.
Various laminates fabricated from a non-woven synthetic materials and non-woven mineral materials are known in the industry. For example, DE 197 39 049 A 1 discloses a process, wherein continuous filaments are laid on an endless sieve directly after their formation in order to produce a non-woven of uniform thickness. Hydrodynamic needling then takes place in order to produce a high strength non-woven. The needled non-woven containing continuous fibers is preferably fixed before being coated with bitumen. The hydraulically needled continuous filament non-woven prior to coating with bitumen, a glass fiber non-woven can be provided or bound thereon.
European Patent Document EP 0 285 533 B1 discloses a composite consisting of a non-woven fiber web combined with a textile grid in which the fiber webs are non-wovens made of staple fibers. The staple fibers may be based on polyester fibers or glass fibers. The interlocking of the non-wovens and the textile grid is obtained by hydraulic needling.
European Patent Document EPO 315 553 B1 also discloses composites based on non-wovens, which are bound to one another by hydraulic needling. The upper layer, (i.e., the upper non-woven) consists of staple fibers, the layer underneath is also a non-woven and consists of relatively rigid and brittle fibers such as glass, asbestos, etc. Further, this document discloses that it is essential that during the needling process the fibers of the upper first non-woven penetrate into the second non-woven but do not protrude through the surface of the second non-woven.
Finally, European Patent Document EP 403 403 B1 describes a further development of the subject matter of EP 0 315 553 B1. The fibers of the non-woven consisting of stiff inorganic fibers are essentially arranged parallel to the sheet surface. Such non-wovens are for instance produced during a wet process which is usually employed in the production of paper. Thus, the document proposes providing inorganic fiber non-wovens with perforations prior to the binding with the synthetic fiber non-woven in order for synthetic fibers to better penetrate the non-woven made of inorganic fibers.
Although numerous processes are known for the production of carrier webs which can serve as carriers for bituminized roofing felts, a need for improved carriers (i.e., having improved mechanical strength, fire retardant properties, etc.) and processes for the production thereof, in a fast and facile manner remains.
To meet the requirements of the roofing, sealing, flooring and insulating industries and to overcome the disadvantages of the related art, it is an object of the present invention to provide a method for the production of bounded non-woven carriers wherein the non-woven are hydro-dynamically needled, thus minimizing the need to employ a binder for final consolidation.
It is a further object of the invention, to provide carrier webs with special property profiles that may be adjusted to meet the special purposes for which it is used.
It is another object of the invention, to provide a non-woven laminate having improved dimensional stability as well as improved stability during the end step (e.g., bituminization step).
It is yet another object of the invention, to provide a non-woven laminate composite having improved delamination resistance, wherein the laminate is compatible with coating and impregnation materials.
It is a further object of the invention, to provide a laminate having improved perforation stability and tear propagation resistance, as well as improved fire behavior after being coated or impregnated.
It is another object of the invention, to provide a laminate having a particular density and thus, having a desired thickness.
Other objects and aspects of the invention will become apparent to one of ordinary skill in the art upon review of the specification and claims appended hereto.
SUMMARY OF THE INVENTION
In accordance with the inventive non-woven laminate composite and method of production thereof, it has been determined that a laminate of two or more layers hydro-dynamically consolidated does not require a binder, or at the very least it is minimized.
In accordance to one aspect of the invention, a method for the production of bounded non-wovens carriers is provided. The method includes providing a glass staple fiber containing non-woven which is pre-consolidated with a binder, placing the glass staple fiber containing non-woven adjacent to one or-more non-wovens of synthetic fibers and hydro-dynamically needling the adjacent non-wovens at a water beam pressure in the range of 100 to 400 bar.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION
The invention will now be described with reference to exemplary embodiments thereof. In a preferred embodiment of the invention, a glass staple fiber containing non-woven pre-consolidated by a binder is disposed adjacent to one or more non-woven of synthetic fibers. The non-wovens are bounded by hydro-dynamically needling at a water beam pressure in a range of 100 to 400 bar to produce a carrier of bounded non-wovens.
The non-woven of synthetic material can be staple fibers, but preferably filamentous fibers. These filamentous fibers are also known to those skilled in the art as “endless” or continuous fibers. The staple fibers or filaments may be present as multi-component fibers, in particular as bico fibers which are well known in the art. Suitable fiber materials can be selected from a group of polymers or copolymers such as polyester, poly(ethylene terephthalate), polypropylene, polyamides or polyolefins. Preferably, polypropylene and more preferably poly(ethylene terephthalate) are employed. In an exemplary embodiment, the synthetic non-wovens can be pre-consolidated mechanically, hydro dynamically, thermally or by calendering at temperatures where the synthetic fibers would shrink in totality. Further, the synthetic non-woven can be shrunk before bonding with the glass non-woven layer, prior or after pre-consolidation, but before bonding with the glass fiber non-woven.
The laminate is preferably needled at a water beam pressure of 200 to 300 bar and an energy of the water jets of 0.05 to 10 kwh/kg laminate. Advantageously, the synthetic organic filament non-woven utilized has a weight per unit area of 50 to 250 g/m
2
and has a filament titers of 1 to 8 dtex, preferably 1.5 to 4 dtex. It will readily be recognized by those skilled in the art that dtex or tex is a unit of measurement of g/10,000 m or g/1,000 m, respectively.
In the exemplary embodiment, the glass non-woven of staple fibers is pre-consolidated with a binder prior to bonding to the synthetic non-woven by needling. The glass fibers have a weight per unit are of about 30 to 150 g/m
2
. The diameter of the glass fibers is about 8 to 16 &mgr;m, and preferably about 10 to 13 &mgr;m. The length of the fibers is about 8 to 32 mm, and preferably 8 to 18 mm. Suitable binder include water insoluble binders such as acrylate polymerized preferably with vinyl-acetate or styrene, urea formaldehyde, melamine formaldehyde, phenolic, epoxy, vinyl acetate, polyvinyl chloride, vinyl alcohol, acrylate and other thermoplastic and thermosetting resin.
The non-woven of glass fiber is produced in accordance to a so-called wet process to align the fibers in a more parallel fashion. Fibers of the E class, C class, mixtures thereof, and ECR glass are pre-consolidated with acrylic, urea-formaldehyde or melamine formaldehyde binders. Wet setting is performed, and a coating ranging from about 5 to 45 percent,
Burns Doane , Swecker, Mathis LLP
Johns Manville International Inc.
Vanatta Amy B.
LandOfFree
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