Textiles: weaving – Fabrics – Drier felts
Reexamination Certificate
1999-11-02
2001-02-20
Falik, Andy (Department: 3741)
Textiles: weaving
Fabrics
Drier felts
C139S3830AA
Reexamination Certificate
active
06189577
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to papermakers fabrics and in particular to fabrics comprised of flat monofilament yarns.
2. Description of Related Art
Papermaking machines generally are comprised of three sections: forming, pressing, and drying. Papermakers fabrics are employed to transport a continuous paper sheet through the papermaking equipment as the paper is being manufactured. The requirements and desirable characteristics of papermakers fabrics vary in accordance with the particular section of the machine where the respective fabrics are utilized.
With the development of synthetic yarns, shaped monofilament yarns have been employed in the construction of papermakers fabrics. For example, U.S. Pat. No. 4,290,209 discloses a fabric woven of flat monofilament warp yarns; U.S. Pat. No. 4,755,420 discloses a non-woven construction where the papermakers fabric is comprised of spirals made from flat monofilament yarns.
Numerous weaves are known in the art which are employed to achieve different results. For example, U.S. Pat. No. 4,438,788 discloses a dryer fabric having three layers of cross machine direction yarns interwoven with a system of flat monofilament machine direction yarns such that floats are created on both the top and bottom surfaces of the fabric. The floats tend to provide a smooth surface for the fabric.
Permeability is an important criteria in the design of papermakers fabrics. In particular, with respect to fabrics made for running at high speeds on modern drying equipment, it is desirable to provide dryer fabrics with relatively low permeability.
U.S. Pat. No. 4,290,209 discloses the use of flat monofilament warp yarns woven contiguous with each other to provide a fabric with reduced permeability. However, even where flat warp yarns are woven contiguous with each other, additional means, such as stuffer yarns, are required to reduce the permeability of the fabric. As pointed out in that patent, it is desirable to avoid the use of fluffy, bulky stuffer yarns to reduce permeability which make the fabric susceptible to picking up foreign substances or retaining water.
U.S. Pat. No. 4,290,209 and U.S. Pat. No. 4,755,420 note practical limitations in the aspect ratio (cross-sectional width to height ratio) of machine direction warp yarns defining the structural weave of a fabric. The highest practical aspect ratio disclosed in those patents is 3:1, and the aspect ratio is preferably, less than 2:1.
U.S. Pat. No. 4,621,663, assigned to the assignee of the present invention, discloses one attempt to utilize high aspect ratio yarns (on the order of 5:1 and above) to define the surface of a papermakers dryer fabric. As disclosed in that patent, a woven base fabric is provided to support the high aspect ratio surface yarns. The woven base fabric is comprised of conventional round yarns and provides structural support and stability to the fabric disclosed in that patent.
U.S. Pat. No. 4,815,499 discloses the use of flat yarns in the context of a forming fabric. That patent discloses a composite fabric comprised of an upper fabric and a lower fabric tied together by binder yarns. The aspect ratio employed for the flat machine direction yarns in both the upper and lower fabrics are well under 3:1.
SUMMARY OF THE INVENTION
The present invention provides a method for weaving a papermakers fabric having a system of flat monofilament machine direction yarns (hereinafter MD yarns) which are stacked to control the permeability of the fabric. The system of MD yarns comprises at least upper and lower layers of yarns. Preferably, each upper MD yarn is paired in a vertically stacked orientation with a lower MD yarn.
The fabric has a variety of industrial uses. For example, it may be used as a base fabric for a papermakers wet press felt or as a dryer fabric. Preferably, multiple layers of stacked CMD yarns are provided which are maintained in the stacked relationship by the flat stacked MD yarns to provide suitable void volume within the fabric. Preferably, three layers of stacked CMD yarns are provided. In a low permeability embodiment, at least the upper MD yarns are flat monofilament yarns woven contiguous with each other.
Preferably, the same type and size yarns are used throughout the machine direction yarn system and both the top and the bottom MD yarns. Where three layers of CMD yarns are used, the middle layer CMD yarns are preferably of a smaller diameter than the upper and lower CMD layer yarns if the fabric is intended to be used as a press base fabric. For dryer fabrics, the CMD yarns are preferably all the same.
It is an object of the invention to provide a method for weaving a papermakers fabric having permeability controlled with woven flat machine direction yarns.
Other objects and advantages will become apparent from the following description of presently preferred embodiments.
REFERENCES:
patent: 926310 (1909-06-01), Zepp et al.
patent: 1050406 (1913-01-01), Veit
patent: 1268788 (1918-06-01), Brooks
patent: 1775144 (1930-09-01), Sherman
patent: 1830620 (1931-11-01), Pelton
patent: 1964419 (1934-06-01), Asten
patent: 2003123 (1935-05-01), Specht
patent: 2093904 (1937-09-01), Bierer
patent: 2135057 (1938-11-01), Slayter et al.
patent: 2554034 (1951-05-01), Koester et al.
patent: 2570576 (1951-10-01), Lord
patent: 2619683 (1952-12-01), Murray
patent: 2854032 (1958-09-01), Santos
patent: 3622415 (1971-11-01), Kunsman
patent: 3657068 (1972-04-01), Ivanowicz
patent: 3815645 (1974-06-01), Codorniu
patent: 3851681 (1974-12-01), Egan
patent: 4026331 (1977-05-01), Lees et al.
patent: 4123022 (1978-10-01), Dutt et al.
patent: 4142557 (1979-03-01), Kositzke
patent: 4184519 (1980-01-01), McDonald et al.
patent: 4290209 (1981-09-01), Buchanan et al.
patent: 4308897 (1982-01-01), Westhead
patent: 4351874 (1982-09-01), Kirby
patent: 4356225 (1982-10-01), Dufour
patent: 4369218 (1983-01-01), Mazere
patent: 4379735 (1983-04-01), MacBean
patent: 4414263 (1983-11-01), Miller et al.
patent: 4421819 (1983-12-01), Baker
patent: 4423755 (1984-01-01), Thompson
patent: 4438788 (1984-03-01), Harwood
patent: 4438789 (1984-03-01), MacBean
patent: 4461803 (1984-07-01), Booth et al.
patent: 4469142 (1984-09-01), Harwood
patent: 4470434 (1984-09-01), Vuorio
patent: 4537816 (1985-08-01), Booth et al.
patent: 4565735 (1986-01-01), Murka, Jr. et al.
patent: 4569883 (1986-02-01), Renjilian
patent: 4574435 (1986-03-01), Luciano et al.
patent: 4601785 (1986-07-01), Lilja et al.
patent: 4621663 (1986-11-01), Malmendier
patent: 4676278 (1987-06-01), Dutt
patent: 4695498 (1987-09-01), Sarrazin et al.
patent: 4705601 (1987-11-01), Chiu
patent: 4737241 (1988-04-01), Gulya
patent: 4749007 (1988-06-01), Malmendier
patent: 4755420 (1988-07-01), Baker et al.
patent: 4806208 (1989-02-01), Penven
patent: 4815499 (1989-03-01), Johnson
patent: 4824525 (1989-04-01), Penven
patent: 4829681 (1989-05-01), Josef
patent: 4846231 (1989-07-01), Penven
patent: 4865083 (1989-09-01), Cunnane
patent: 4867206 (1989-09-01), Kufferath
patent: 4883096 (1989-11-01), Penven
patent: 4887648 (1989-12-01), Cunnane
patent: 4902383 (1990-02-01), Penven
patent: 4921750 (1990-05-01), Todd
patent: 4938269 (1990-07-01), Nicholas et al.
patent: 4989647 (1991-02-01), Marchand
patent: 4991630 (1991-02-01), Penven
patent: 5023132 (1991-06-01), Stanley et al.
patent: 5066532 (1991-11-01), Gaisser
patent: 5089324 (1992-02-01), Jackson
patent: 5103874 (1992-04-01), Lee
patent: 5114777 (1992-05-01), Gaisser
patent: 5117865 (1992-06-01), Lee
patent: 5151316 (1992-09-01), Durkin et al.
patent: 5164249 (1992-11-01), Tyler et al.
patent: 5167261 (1992-12-01), Lee
patent: 5199467 (1993-04-01), Lee
patent: 5230371 (1993-07-01), Lee
patent: 5254398 (1993-10-01), Graisser
patent: 5343896 (1994-09-01), Schroder et al.
patent: 5358014 (1994-10-01), Kovar
patent: 5366778 (1994-11-01), Johnson
patent: 5449026 (1995-09-01), Lee
patent: 5503196 (1996-04-01), Josef et al.
patent: 5597450 (1997-01-01), Baker et al.
patent: 5645112 (1997-07-01), Lee
patent: 5713396 (1998-02-01), Lee
patent: 5769131 (1998-0
AstenJohnson, Inc.
Falik Andy
Volpe and Koenig P.C.
LandOfFree
Papermakers fabric with stacked machine direction yarns does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Papermakers fabric with stacked machine direction yarns, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Papermakers fabric with stacked machine direction yarns will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2608988