US 3722469 A
Apparatus for distributing coating and impregnates on a web of non-woven fabric, the apparatus including a distribution system in which the length of each branch pipe of the system is equal to the length of each other branch pipe, desirably the sum of the cross sectional areas of the branch pipes is equal to the cross sectional area of the pipe from which the branches are taken, the discharge ends of all of the branching pipes being arranged in a straight line in the same plane and discharging their contents above the nip between two rolls mounted together below the discharge ends of the branching pipes, between which rolls the web of non-woven fabric passes, and means for reciprocating such discharge ends transversely of the path of travel of said web onto which the coating or impregnate is being applied and parallel to the lengths of said rolls.
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limited States Patent [191 Bartley et al.
[ FOAM HEADER ASSEMBLY  Inventors: Thomas S. Bartley, Mobile, Ala.; Paul A. Wagenknecht, Stafiord Springs, Conn.
 Assignee: International Paper Company, New
 Filed: May 19, 1971  Appl. No.: 144,924
 US. Cl ..118/414, 118/262  Int. Cl. ..B05c 3/12  Field of Search ,.118/407, 414, 417, 262, 323, 118/405; 101/366  References Cited UNITED STATES PATENTS 2,712,508 7/1955 Massey..... ....1 18/407 X 2,989,422 6/1961 Helbing ..118/407 X 1,401,504 12/1921 Sykora.... 18/411 UX 2,003,778 6/1935 Willis ..118/323 X 2,133,881 10/1938 Weiss ..101/366X 2,604,067 7/1952 Richmond et a1 ..l18/262 UX [4 1 Mar. 27, 1973 2,015,531 9/1935 Montgomery ..1 18/407 X Primary ExaminerJohn P. McIntosh Attorney-Louis F. Reed ABSTRACT Apparatus for distributing coating and impregnates on a web of non-woven fabric, the apparatus including a distribution system in which the length of each branch pipe of the system is equal to the length of each other branch pipe, desirably the sum of the cross sectional areas of the branch pipes is equal to the cross sectional area of the pipe from which the branches are taken, the discharge ends of all of the branching pipes being arranged in a straight line in the same plane and discharging their contents above the nip between two rolls mounted together below the discharge ends of the branching pipes, between which rolls the web of non-woven fabric passes, and means for reciprocating such discharge ends transversely of the path of travel of said web onto which the coating or impregnate is being applied and parallel to the lengths of said rolls.
5 Claims, 9 Drawing Figures FOAM HEADER ASSEMBLY BACKGROUND OF THE INVENTION The present invention relates, in general, to apparatus for coating or applying impregnating materials to flat webs or foils, more particularly non-woven fabric, where the coating or impregnating material is a synthetic dispersion, glue solution or foam originating from a supply point external of the machine and to be applied to a relatively wide web or web area on the machine.
There are a number of known processes for coating or impregnating flat web materials with synthetic dispersions, glues, pastes, foam, and the like. Such known processes can be generally divided into three classes. In the first class, the web to be coated or impregnated is carried through or dipped into a vat or tank filled with the material to be deposited or impregnated. In the second class, the coating or impregnating material is supplied to the web through funnels. In the third class, the material is supplied to a pond formed between rolls, rotating in opposite directions, between which the web to be impregnated is passed and between which said pond of the material to be impregnated or coated onto the web is fed. In such latter process, the coating or impregnating material is deposited on the web, as itpasses between the rolls, from the pond. The present invention is directed to an improvement in a process of the latter type, i.e., wherein the impregnating material is fed into a pond of the material formed between the oppositely rotating rolls, between which the web to be impregnated passes.
The known processes of coating or impregnating flat relatively wide webs at high speed do not provide even distribution of the coating or impregnating material over all of the relatively wide web. The amount of material coating or impregnating the web in such processes across the width of the relatively wide web may vary and the age, viscosity, and other characteristics of the deposited material, from point to point across the web, may also vary. For example, where the material to be coated or deposited on the web is a thermoplastic material, the age of the thermoplastic material, which may be of considerable importance to the materials properties after such material is coated or deposited on the web of non-woven fabric web, will be less on one point across the web where such material is deposited than at other points. Where the material tends to crystallize or be crystalline the crystallinity may vary from point to point. Where the material to be coated or impregnated onto the non-woven web is, for example, a paint, the viscosity of such paint across the web may vary. These variances or irregularities in the coating or impregnating material itself or in the amount of such material deposited or impregnated on the nonwoven web result in variations in tensile strength, color and other irregularities in the web.
The apparatus of the instant invention overcomes the problems of irregularities and variations in the coating or impregnating material and variations in the amount of such material that is coated or deposited across the width of relatively wide non-woven webs, travelling at high speed. The properties of the materials coated or impregnated across the web, in the instant apparatus, are identical and the amount of such material so deposited or coated is substantially uniform.
SUMMARY OF THE INVENTION In the apparatus of the present invention, the path of travel of the impregnating material or foam from the supply point to each point on the web, across the web width, is approximately equal. Thus, the material coated or impregnated onto the non-woven fabric at each area across the fabric web is of uniform composition, age, viscosity, and the like. This is accomplished with a distributor, through which the coating or impregnating material is fed and applied to the web, in which the path of flow from the material supply to each outlet is of substantially equal length. The sum of the cross sectional areas of the branch pipes is desirably equal to that of the pipe from which the branches are taken.
The discharge of the impregnating material or foam from the pipe outlets, wherein the outlets are arranged in a straight line in a single plane, feeds the impregnating material between oppositely rotating rolls to form a pond in the nip between said oppositely rotating rolls. The non-woven web is passed between the same rolls whereby it acquires a uniform coating of the impregnating material as it passes through the pond.
In the apparatus of the invention, the ends of the discharge pipes of the distribution system are uniformly oscillated transversely to the direction of web motion and of the rotation of the two rolls. Such oscillation, even with a relatively short spacing between the distributor outlets, provides continuous coverage by the distributor outlets across the web width and the length of the two rolls. This is particularly useful where the non-woven fabric will be adversely affected by any unevenness in the distribution of the coating or impregnating material across the web width.
BRIEF DESCRIPTION OF THE DRAWINGS The invention will be more fully understood from the following description and accompanying drawings in which:
FIG. 1 is a side elevation of the machine with a fragmentary showing of its frame.
FIG. 2 is a top plan taken along line 2-2, FIG. 1, again with the frame in fragmentary illustration and parts of the mechanism broken away.
FIGS. 3 and 4 are end views of FIG. l'showing the left end in FIG. 3 and the right end in FIG. 4, respectively.
FIG. 5 is a fragmentary vertical sectional view along line 55 in FIG. 1.
FIG. 6 is a horizontal section along line 6-6, FIG. 5, thru the chamber of the radial distribution unit with parts broken away.
FIG. 7 is a side elevation of flexible tube holder or frame member 25 taken along line 7-7, FIG. 5.
FIG. 8 is an enlarged vertical section along line 88, FIG. 7, showing the tube clamping means.
FIG. 9 is a horizontal sectional view along line 9-9, Fig. 7, further illustrating the tube clamping means.
- DESCRIPTION OF AN ILLU-STRATIVE EMBODIMENT Referring to the drawings, the apparatus of the instant invention includes supply pipe 2 connected to-a pump (not shown) and source of impregnating or coating material to be applied to the web. Supply pipe 2 divides into two branches 8, of equal length and cross section which, in turn, divide into branches 12, 14, 16, 18, respectively, each of the branches 12, 14, 16, 18 being of equal length and cross section. Branches 12, 14 and 16, 18, each in turn empty into annular or radial distribution members 19a, 19b, 19c and 19d, respectively, which in turn radiate, respectively, to a plurality of rigid pipes 20, as shown in FIG. 6, each of equal cross section and length. Rigid pipes 20, in turn communicate with flexible tubes 21,- all of equal cross section and length, which are bent as shown in FIG. 5, so that their discharge ends 24 are fastened to frame member 25 so that all nozzles 26 are in a straight line fixed in a single plane capable of discharging the impregnating material 27 or foam in the nip 30 between the oppositely rotating rolls 32 and 34 to form the pond 36. The non-woven fabric web 38 to be impregnated is moved under the pond 36 and between rolls 32 and 34, as shown at FIG. 5, by moving over roll 32 and under roll 34. Supply pipe 2', branches 8, 10 and 12, 14, 16, 18, annular members 19a, 19b, 19c and 19d, and rigid pipes are all interconnected, such as by welding or other suitable connecting means as shown, to form a single, rigid, unitary unit which is suspended from machine frame 70. Machine frame 70 is rigidly connected, such as by welding or similar means to pipe '2 and its appendages. The discharge ends 24 of flexible tubes 21 are mounted movable in the direction of the arrows, FIG. 1, on frame member 25, on supports 76, 78. Frame member 25, with the discharge ends 24 of flexible tubes 21 are oscillated reciprocally transverse to the direction of travel of the non-woven fabric web 38 and the oppositely rotating rolls 32, 34, by actuator 80 powered by suitable means.
Each of the rotating rolls 32, 34, are provided with hearing means 60, 61, to adjust the pressure of the rolls toward each other. As shown in FIG. 3, the left roll bearing 60 is a fixed one and the right roll bearing61 is a swinging adjustment bearing which is adjusted by adjuster 62 to provide the desired adjustment of pressure between the two rolls 32, 24 to permit formation of the pond and application of suitable pressure upon the web 38. In accordance with one embodiment the two rolls are pneumatically loaded together and means are provided whereby there are micrometer adjustable stops between the bearing housings so that the two rolls are run in close proximity to each other.
As shown in FIGS. 3,, 4 and 5, end boards 50 are supplied at the ends of the rolls 32, 34 to prevent the pond 36 from draining away.
As shown in FIGS. 8 and 9, the ends of the flexible tubes 24 are mounted in the frame member by bolts 70 and 71. This permits easy dismantling and cleaning of the tubes and the apparatus.
In the operation of the apparatus, non-woven fabric web 38 is fed over roll 32, under pond 36 and under roll 34 as shown in FIG. 5. The speed of the web and the rolls is the same. The material to be impregnated or coated on non-woven fabric web 38 is fed through pipe 2 and thence through branches 8, 10, and then branches 12, 14, 16, 18, annular members 19a, 19b, 19c, 19d, then through rigid pipes 20,- flexible tubes 21 and out the nozzles 26 from which the impregnating material is discharged to form and feed pond 36 and impregnated or coated onto non-woven fabric web 38.
The rotating rolls 32, 34, form a funnel to apply the impregnating material. The paths of travel of the coating or impregnating material from pipe 2 to each of the nozzles 26 is of the same length. Thus, the age and the amount of coating or impregnating material discharged at each nozzle is the same. The oscillation of the nozzles 26 of the flexible tubes 21 transverse to the direction of non-woven fabric web 38 distributes the impregnating or coating material substantially uniformly across the width of non-woven fabric web 38. The maintenance of the uniform pond and action of the rolls assists in providing uniform distribution of the impregnating or coating material.
In the distributor system of the instant invention, the combined interior cross section of the branches, where the preceding line of the distribution system is branched, at each point, is preferably equal to the cross section of the line from which such branches are taken. For example, the combined internal cross section of branches 8 and 10 is equal to the cross section of pipe 2. The combined internal cross section area of branches 12, 14 is equal to the cross section of branch 8, etc. Thus, at each point where the flow of impregnating or coating material is divided, the division of material is preferably made equally.
The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof,
but it is recognized that various modifications are possible.
What is claimed is:
1. Apparatus for coating and impregnating a nonwoven fabric web, comprising supply means for providing coating and impregnating materials, distributor means from said supply means to a plurality of nozzles, all of which nozzles being fixed in a straight line in the same plane, the length of said distributor means from said supply means to each of said nozzles being substantially equal, said distributor means including a plurality of radial distribution chambers each having eminating radially therefrom a tube each communicating with one of said nozzles, said plurality of nozzles providing discharge of coating and impregnating material at the interface of oppositely rotating rolls between which the non-woven fabric web to be coated and impregnated passes to provide and maintain a supply of coating and impregnating material between the interface of the rolls, and means for oscillating said plurality of nozzles parallel to the length of said rolls.
2. Apparatus according to claim 1 in which said distributor means includes a branching, symmetrical piping system, the sum of the cross sectional areas of each of said branching pipes being equal to'the cross sectional area of the pipe from which said branches are connected.
3. Apparatus according to claim 1 in which at least one of said rolls is adjustable to provide variable pressure between the rolls.
4. Apparatus according to claim 1 in which the plurality of tubes are flexible.
5. Apparatus for coating and impregnating a nonwoven fabric web, comprising supply means for providing coating and impregnating materials, distributor radial distribution chambers each having eminating radially therefrom a flexible tube each communicating with one of said nozzles, said plurality of nozzles providing discharge of coating and impregnating material at the interface of said oppositely rotating rolls to provide and maintain a supply of coating and impregnating material from the interface of the rolls, and means for oscillating said plurality of nozzles parallel to the length of said rolls.
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