Variable spacing strand coating method

Strand coating methods having an applicator head pivotally mounted adjacent a substrate, a coating material dispenser mounted on the applicator head, a strand guide mounted on the applicator head, wherein the strand guide and the coating material dispenser are adjustably positionable in unison relative to the substrate by pivoting the applicator head to vary the spacing of the strands relative to the substrate.

BACKGROUND OF THE INVENTION

The invention relates generally to strand coating, and more particularly to variable spacing strand coating systems and methods therefor.

An object of the present invention is to provide novel strand coating methods and systems that overcome problems in and improve upon the prior art.

Another object of the invention is to provide in some embodiments thereof novel strand coating methods and systems that are economical.

A further object of the invention is to provide in some embodiments thereof novel strand coating methods and systems that are reliable.

Another object of the invention is to provide in some embodiments thereof novel strand coating methods and systems for variably spacing a plurality of strands.

Another object of the invention is to provide in some embodiments thereof novel strand coating methods and systems for variably spacing a plurality of strands relative to a substrate without changing coating material dispensers or strand guides.

A further object of the invention is to provide in some embodiments thereof novel strand coating methods and systems for variably spacing a plurality of strands without resetting system fluid and air pressure.

Yet another object of the invention is to provide in some embodiments thereof novel strand coating methods and systems for more accurately aligning one or more strands relative to a coating material dispenser.

Another object of the invention is to provide in some embodiments thereof novel strand coating methods and systems that are less susceptible to misalignment.

Still another object of the invention is to provide in some embodiments thereof novel strand coating methods and systems having adjustable strand guides.

Another object of the invention is to provide in some embodiments thereof novel strand coating methods and systems having coating material dispensers with strand guides coupled thereto.

A further object of the invention is to provide in some embodiments thereof novel strand coating methods and systems having coating material dispensers with strand guides coupled thereto that are pivotally adjustable relative to a substrate.

A more particular object of the invention is to provide in some embodiments thereof novel strand coating methods and systems comprising a strand guide having a guiding surface at an angle relative to a moving substrate, a plurality of moving strands disposed side by side over the guiding surface of the strand guide, and a coating material dispenser disposed adjacent the plurality of strands.

Another more particular object of the invention is to provide in some embodiments thereof novel strand coating methods and apparatuses comprising an applicator head pivotally mounted on a support member, a coating material dispenser mounted on the applicator head, a strand guide mounted on the applicator head, whereby the strand guide and the coating material dispenser are adjustably positionable in unison by pivoting the applicator head.

Yet another more particular object of the invention is to provide in some embodiments thereof novel strand coating methods and apparatuses comprising a coating material applicator having a dispenser with at least one orifice, a roller pin extending from a roller arm adjustably coupled to the coating material applicator by a pivot member, and a strand guide roller having a plurality of grooves disposed about a rotation axis thereof, the strand guide roller rotatably coupled to the roller pin.

Still another more particular object of the invention is to provide in some embodiments thereof novel strand coating systems and methods comprising drawing a plurality of strands side by side, in spaced apart relation over a strand guide adjacent a substrate, applying coating material from a coating material dispenser onto the plurality of strands on a downstream side of the strand guide, depositing the plurality of strands with the coating material applied thereto onto the substrate, adjusting a spacing of the plurality of strands on the substrate by changing an orientation of the strand guide relative to the substrate.

These and other objects, aspects, features and advantages of the present invention will become more fully apparent upon careful consideration of the following Detailed Description of the Invention and the accompanying Drawings, which may be disproportionate for ease of understanding, wherein like structure and steps are referenced generally by corresponding numerals and indicators.

DETAILED DESCRIPTION OF THE INVENTION

InFIG. 1, the strand coating system comprises a coating material dispenser10that applies a coating material, for example a hot melt adhesive or an atomized substance, onto one or more strands, identified collectively by numeral20, moving relative thereto.

The strands20may, for example, be elastic rubber or Lycra materials used in the manufacture of diapers, incontinence pads and hospital garments. The strands may also be wire or cable, for example fiber optic cable, or some other elongated member onto which it is desirable to deposit a coating material.

InFIG. 3, the exemplary dispenser10includes a plurality of conduits12, shown only partially and in phantom, terminating at corresponding orifices arranged in a spaced apart series on a side14of the dispenser. The orifices of the exemplary dispenser each emit therefrom a corresponding coating material flow16, which may be a substantially continuous or discrete vacillating filament or an atomized spray, toward a corresponding strand in alignment with the orifice.

InFIG. 3, some of the orifices13are illustrated schematically at the origin of the corresponding flows16spaced apart evenly in a single row on the dispenser. The orifices may be recessed or protrude from the side14of the dispenser. In other embodiments, the spacing between adjacent orifices is not necessarily the same. Alternatively, there may be more than one row or series of orifices arranged in alignment with the direction of the strand so that more than one orifice dispenses coating material onto each strand. In other embodiments, the orifices of adjacent rows may be offset.

Coating material dispensers suitable for use with the present invention are disclosed for example in U.S. Pat. No. 5,902,540, entitled “Meltblowing Method and Apparatus”, and U.S. Pat. No. 5,904,298, entitled “Improved Meltblowing Method and System”. These preferred exemplary devices are capable of producing filaments and atomized spray patterns that vacillate predominately non-parallel to the axis of the strands and provide precise control over the coating material dispensed therefrom.

In one embodiment, illustrated inFIG. 3, the coating material dispenser10dispenses substantially continuous coating material filaments17having a repeating, generally omega shaped pattern from the orifices thereof, only one of which is illustrated, as disclosed more fully in co-pending U.S. application Ser. No. 09/143,883 entitled “Omega Spray Pattern And Method Therefor”, which is assigned commonly with the present application and is incorporated herein by reference.

In other embodiments, the coating material dispenser may be a spiral spray nozzle having a single orifice that dispenses a corresponding spiral filament onto one or more strands, or alternatively some other coating material dispensing apparatus.

InFIG. 5, the exemplary coating material dispenser10is coupled to or mounted on an applicator head40, which supplies coating material and in some embodiments heated air to the coating material dispenser, for example through a nozzle module41, as is known generally by those having ordinary skill in the art.

In some applications, strands having coating material applied thereto are adhered to or deposited on a substrate moving relative to the coating material dispenser, usually in unison with the strands. The coating material dispenser however may move relative to the one or more strands and any substrate.

A strand guide having a guiding surface is preferably disposed adjacent the coating material dispenser, preferably on an upstream side thereof, to guide the strands past the coating material dispenser. The one or more strands are generally drawn over the guiding surface of the strand guide, which aligns the strands side by side in spaced apart relation relative to corresponding orifices of the coating material dispenser, for dispensing coating material dispensed therefrom onto the strands.

In the exemplary embodiment ofFIG. 1, the strand guide is a rotatable roller50and the strand guiding surface thereof includes a plurality of spaced apart grooves52disposed thereabout. The strands are each disposed in a corresponding groove52. The spacing of at least some of the grooves generally corresponds with the spacing of the dispenser orifices. In the exemplary embodiment, the roller aligns and guides the strands adjacent a corresponding orifice of the coating material dispenser, as illustrated in FIG.3. In alternative embodiments, the strand guide may have other configurations besides a channeled roller.

The strand guide is preferably coupled to the coating material dispenser, in fixed relation relative thereto. In the exemplary embodiment, the coating material dispenser and strand guide are both coupled to the applicator head, thereby eliminating or at least substantially reducing any misalignment therebetween, for example misalignment caused by vibrating machinery, as frequently occurs in prior art systems having the strand guide coupled to machinery other than the coating material dispenser.

InFIGS. 1,2and5, the exemplary roller guide50is rotatably coupled to a roller axle or shaft54, preferably with roller bearings. InFIGS. 1 and 2, the exemplary roller guide50is retained on the roller shaft54by a collar56fastened thereto with a set screw or other fastening means.

InFIGS. 2 and 5, the roller shaft54extends from a roller arm58adjustably coupled to the applicator head40. The roller shaft is also preferably adjustably coupled to the roller arm, for example by threaded engagement with a threaded opening59of the roller arm58. In the exemplary embodiment, the roller guide50and/or roller shaft54is adjustable in either direction along the axis of the shaft54to align the guide grooves of the roller50relative to the one or more orifices of the coating material dispenser.

InFIGS. 2 and 5, the roller arm58is pivotally coupled to a guide arm62by a pivot pin64extending from one or the other. The guide arm62is also preferably adjustably coupled to the applicator, for example by a pivot pin66extending from a bracket63mounted thereon.

InFIG. 5, the guide roller50may be adjustably positioned toward and away from a bottom side42the applicator head40. The guide roller50may also be adjustably positioned in the upstream and downstream direction of the strands, closer or farther away from the dispenser.

In the exemplary embodiment ofFIG. 5, the roller axle54is secured in the opening59of the roller arm58by a bolt60disposed through prongs61thereof, which are clamped about the shaft54upon tightening the bolt. The guide arm62is similarly secured to the pivot pin66, and the roller arm58is similarly secured to the guide arm62. In other embodiments, the guide roller is adjustably coupled to the applicator head by other structure.

In some embodiments of the invention, the strand guide is adjustably mounted on a pivot member to change the orientation of the guiding surface of the strand guide to vary the spacing of the strands relative to the substrate. The coating material dispenser is preferably adjustable in unison with the strand guide, for example by adjusting the position or orientation of the applicator head, to facilitate application of the coating material onto the strands.

In the exemplary embodiments ofFIGS. 3 and 4, spacing between the plurality of strands20as they are deposited onto the substrate30is varied by changing the orientation of the strand guide, not illustrated, and particularly the guiding surface thereof relative to a surface32of the substrate. The plane of the strands20corresponds generally to the orientation of the guiding surface of the strand guide relative to the substrate surface32.

In the embodiment ofFIG. 1, the grooved guiding surface of the strand guide50is parallel to the substrate surface32, so that the plane of the strands20is also parallel to the substrate, as illustrated best in FIG.3. The spacing between adjacent strands relative to the substrate surface32thus corresponds generally with the spacing between the grooves on the strand guide over which the strands are drawn. InFIG. 3, for example the spacing between the outermost strands is D1.

InFIG. 4, the strand guide has been pivoted to orient the grooved guiding surface thereof at an angle relative to the substrate so that the plane of the strands is at a corresponding angle relative to the substrate. The spacing between adjacent strands relative to the substrate surface32is thus reduced in some proportion to the angle between the substrate and the guiding surface of the strand guide over which the strands are drawn. InFIG. 4, the spacing between the outermost strands disposed over an angled strand guide is D2, which is less than the spacing D1in FIG.3.

FIGS. 1 and 2illustrate the applicator head40pivotally mounted on a pivot or bolt shaft70having an axis substantially transverse to the side by side arrangement of the plurality of orifices, which permits adjustment of the orientation of the coating material dispenser and strands, as illustrated inFIGS. 3 and 4. InFIGS. 3 and 4, the pivot axis of the coating material dispenser and strand guide is aligned substantially in a direction of the moving substrate, which moves into or out of the page of the drawing.

InFIGS. 1 and 2, the pivot shaft70extends through a mounting block72supported by a support member74, in the exemplary form of a rod. InFIG. 2, the mounting block72includes one or more arcuate slots76disposed about the pivot shaft70. A bolt77extends through the corresponding slot76and into a threaded bore of the applicator head40.

Engagement of the bolt77with opposite end portions of the slot76limits pivoting or rotation of the applicator head40about the shaft70, and engagement of a head portion of the bolt77with the mounting block72secures the orientation of the applicator head40relative thereto upon tightening the bolt77.

While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific exemplary embodiments herein. The invention is therefore to be limited not by the exemplary embodiments herein, but by all embodiments within the scope and spirit of the appended claims.