Method and apparatus for use in coating elongated bands

(54) METHOD AND APPARATUS FOR USE IN COATING ELONGATED BANDS

(75) Inventors: Raza Hayder, Duluth, GA (US);

Laurence B Saidman, Duluth, GA
(US)

(73) Assignee: Nordson Corporation, Westlake, OH (US)

( * ) Notice: Subject to any disclaimer, the term of this patent is extended or adjusted under 35 U.S.C. 154(b) by 113 days.

(21) Appl. No.: 10/021,176

(22) Filed: Oct. 30, 2001

(65) Prior Publication Data

US 2003/0082309 Al May 1, 2003

(51) Int. CI.7 B05D 5/10; B05D 1/30

(52) U.S. CI 427/256; 427/208; 427/286;

427/288

(58) Field of Search 427/2.31, 207.1,

427/208, 208.2, 256, 280, 286-288, 422;

118/307, 322

(56) References Cited

U.S. PATENT DOCUMENTS

4,025,671 A * 5/1977 Creamer

4,031,854 A 6/1977 Sprague, Jr 118/641

4,135,903 A 1/1979 Ohsato et al 65/5

4,185,981 A 1/1980 Ohsato et al 65/5

4,844,003 A 7/1989 Slautterback et al 118/323

5,171,512 A 12/1992 Mende et al 264/555

5,342,647 A 8/1994 Heindel et al 427/2.31

5,487,512 A 1/1996 Nojiri et al 242/471

5,881,939 A 3/1999 Kikuchi et al 226/180

5,882,573 A 3/1999 Kwok et al 264/510

5,902,540 A 5/1999 Kwok 264/555

5,904,298 A 5/1999 Kwok et al 239/135

6,200,635 Bl * 3/2001 Kwok 427/286

6,520,237 Bl * 2/2003 Bolyard, Ir. et al.

FOREIGN PATENT DOCUMENTS

EP 0 264 454 4/1988 B32B/15/08

GB 1 363 132 8/1974 B65H/23/02

IP 11244774 A 9/1999

OTHER PUBLICATIONS

European Patent Office, European Search Report, Application No. EP02023563, Feb. 13, 2003 (2 pages). Syang-Peng Rwei, Dog-Legging in the Melt Spinning Process, Polymer Engineering and Science, Vol 38, No. 2, pp. 341-347, Feb. 1998.

J&M Laboratories, DurastitchTM Technology, New Product Release Manual, Feb. 1997.

Rajiv S. Rao et al., Vibration and Stability in the Melt Blowing Process, Ind. Eng. Chem., 32, pp. 3100-3111, 1993.

* cited by examiner

Primary Examiner—Fred J. Parker

(74) Attorney, Agent, or Firm—-Wood, Herron & Evans, LLP

(57) ABSTRACT

A guide and method for use in coating of an elongated band with liquid material prior to its attachment to a substrate. The guide supports the band in a tilted orientation relative to a dispensing outlet of a liquid dispenser. The liquid dispenser dispenses a continuous bead or filament of adhesive that wraps around the band to coat the band while it is separate from the substrate. The coated band is thereafter bonded to the substrate.

6 Claims, 2 Drawing Sheets

1

METHOD AND APPARATUS FOR USE IN
COATING ELONGATED BANDS

FIELD OF THE INVENTION

The present invention relates generally to liquid dispensing systems for dispensing liquid material onto substrates and, more particularly, an apparatus and method for use in coating elongated bands of elastic or non-elastic material with an adhesive prior to attachment of the band to a substrate.

BACKGROUND OF THE INVENTION

In the manufacture of disposable diapers, adult incontinence pads and other hygienic articles, it is often desirable to provide a stretchable portion on the article, such as a waist band or leg, so that a relatively tight fluid seal between the article and the body can be formed. Generally, these stretchable portions are formed by bonding stretched elastic strands or bands directly to the fabric with adhesive so that as the strands or bands contract, the fabric is bunched together to form stretchable regions in the fabric. Alternatively, the stretchable strands or bands are bonded to a web of waistband or leg cuff material which is then bonded to selected areas of the article to form stretchable regions in the fabric.

A typical elastic band includes opposite major surfaces that are generally flat and a pair of opposite sides edges that extend between the pair of flat major surfaces. The band is bonded to the fabric by guiding the band toward a dispensing outlet of a liquid adhesive dispenser that dispenses a continuous bead or filament toward the band. The dispensing outlet is provided on a pattern die of the liquid dispenser and is disposed above and spaced from the elongated band as the band travels in the machine direction (MD). The pattern die is configured with multiple air outlets associated with the dispensing outlet to form air jets or process air that causes the pattern of the dispensed bead to expand in the crossmachine (CD) direction during its flight toward the band.

The liquid dispenser has a guide wheel positioned upstream of the dispensing outlet that guides the band in registry with the dispensing axis of the outlet so that the outlet dispenses the continuous bead of adhesive onto the band. The bead of adhesive may be dispensed in a swirl, cross-stitch or other overlapping or non-overlapping pattern toward the band so that the pattern of the dispensed bead expands in the cross-machine direction during its flight toward the band so that the pattern of the bead extends slightly beyond the side edges of the band. The bead of adhesive contacts and wraps around the band to coat the opposite major surfaces of the band prior to its attachment to the fabric. The bead contacts the band at spaced intervals which are determined by the velocity of the band in the machine direction (MD) and the frequency of the dispensed continuous bead. The spacing of the intervals is decreased with either a decrease in the velocity of the band or an increase in the frequency of the dispensed bead. The bead wraps around the band due to the momentum of the bead as it folds around the side edges of the band.

In the past, the guide wheel has guided the band toward the dispensing outlet so that the band lies in a generally horizontal plane transverse to the dispensing axis of the outlet. The outlet dispenses the continuous bead toward the band so that the bead engages the major surface of the band facing the outlet and then wraps around the band to coat the opposite major surface.

Known guide wheels and methods of coating elongated bands with liquid material suffer from several shortcomings

2

and drawbacks. The horizontal orientation of the band relative to the dispensing outlet requires a broad bead pattern to be dispensed toward the band so that the bead properly wraps around the edges of the band. This broad pattern

5 reduces the frequency at which the bead can be dispensed toward the band which, in turn, reduces the effective coating on the major surfaces of the band. Additionally, the horizontal orientation of the band and the associated broad bead pattern causes the dispensed bead to be susceptible to small

10 changes in the pattern air and the location of the band relative to the dispensing axis of the outlet.

Therefore, there is a need for an improved guide for guiding an elongated band toward a dispensing outlet of a liquid dispenser and method for coating an elongated band

15 with liquid material prior to its attachment to a substrate.

SUMMARY OF THE INVENTION

The present invention overcomes the foregoing and other shortcomings and drawbacks of guides and methods here

20 tofore known for use in coating an elongated band with liquid material prior to its attachment to a substrate. While the invention will be described in connection with certain embodiments, it will be understood that the invention is not limited to these embodiments. On the contrary, the invention

25 includes all alternatives, modifications and equivalents as may be included within the spirit and scope of the present invention.

An elongated band to be coated in accordance with the

3Q principles of the present invention includes a pair of opposite major surfaces and a pair of opposite side edges extending between the pair of major surfaces. In accordance with one method of the present invention for coating the elongated band with liquid material dispensed from an outlet of

35 a liquid dispenser, the band is moved in a direction toward the outlet with one of the major surfaces of the band facing the outlet. The band is guided spaced from the outlet with one of the side edges of the band positioned closer to the outlet than the other side edge of the band. Liquid material

4Q is dispensed from the outlet as a continuous bead or filament toward the band to coat the major surfaces of the band with the liquid material.

The bead of adhesive may be dispensed in a swirl, cross-stitch or other pattern toward the band so that the

45 pattern of the dispensed bead expands in the cross-machine direction during its flight toward the band so that the pattern of the bead extends slightly beyond the side edges of the band. The pattern of the dispensed bead may be overlapping or non-overlapping upon contact with the band. The bead of

50 adhesive contacts and wraps around the band to coat the opposite major surfaces of the band prior to its attachment to the substrate.

In accordance with another method of the present invention for coating an elongated band with liquid material

55 dispensed from an outlet of a liquid dispenser, the band is moved in a direction toward the outlet with one of the major surfaces of the band facing the outlet. The band is guided spaced from the outlet with a dispensing axis of the outlet intersecting the major surface of the band facing the outlet

go at an oblique angle. Liquid material is dispensed from the outlet toward the band to coat the major surfaces of the band with the liquid material.

A guide in accordance with the principles of the present invention, such as a rotatable guide wheel in one

65 embodiment, is adapted to be mounted on a shaft for guiding an elongated band toward an outlet of a liquid dispenser capable of dispensing liquid material onto the band. The