US2841202A

US2841202A - Apparatus for forming a multiple web product

Info

Publication number: US2841202A
Application number: US476027A
Authority: US
Inventors: Harlan W Hirschy
Original assignee: Kimberly Clark Corp
Current assignee: Kimberly Clark Corp
Priority date: 1954-12-17
Filing date: 1954-12-17
Publication date: 1958-07-01
Anticipated expiration: 1975-07-01

Description

H. W. HIRSCHY APPARATUS FOR FORMING A MULTIPLY WEB PRODUCT July l', 1958 6 Sheets-Sheet l Filed Dec Nm. `M n mM w @y w hw f/ l A A l QN @A s p Mw mw ww m RN W m ,NN MN VIA NN NN IILI HI l 1 I x I H/ NN MN! l |\\\l /m @NQ \1 hm. mlwm www. WN mwl Nn. NNMNQN mm J, Q W wm um, Nw] MN N@ also@ July 1, 195s H. w. HlRsHY APPARATUS FOR FORMING A MULTIPLY WEB PRODUCT Filed Dec. 17, 1954 6 Sheets-Sheet 2 NNN H..w. HlRscHY 2,841,202 APPARATUS Fox gomme A MULTIPLY WEB PRODUCT July l', 1958 6 Sheets-Sheet 3 lFiled Dec. 17, 1954 July l, 1958 H. w. HnscHY 2,841,202

APPARATUS FOR FORMING A MULTIPLY WEB PRODUCT Filed Dec. 17, 1954 6 Sheets-Sheet 4 PROJECTION OF MAlN SHEET UNWEAPPED j, jg /4 g5 farla/i2 MHz/isc@ gg/60W, 9 @no6/wan@ H. W. HIRSCHY APPARATUS FOR FORMING A MULTIPLY WEB PRODUCT Filed Dec. 17, 1954 July 1, 1 958 6 Sheets-Sheet 5 July 1, 1958 H. w. HlRscHY APPARATUS FOR FORMING A MULTIPLY WEB PRODUCT 6 Sheets-Sheet 6 Filed Dec. 1'7, 1954 ron FORMING A MULTIPLE WEB PRODUCT Harlan W. Hirschy, Neenah, Wis.,

Clark Corporation, Delaware APPARATUS assignor to Kimberly- Neenah, Wis., a corporation of Application December 17, 1954, Serial No. 476,027

' 6 claims. (ci. 1st- 1.7)`

The present invention is concerned with a method and an apparatus for forming thread and web structures in a continuous manner, and is primarily directed Vto the manufacture of thread and web products in whichV means are provided for improving the physical properties of the product by controlled orientation of the elements up the product.

While the present invention has applicability to the manufacture o-f numerous types of products of widely different characteristics, the invention will be described as it is applied to the field of nonwoven web and thread textile products. v

`In some fields, nonwoven Webs composed of cotton fibers, rayon bers, or mixtures of various natural or synthetic fibers have very distinct advantages over woven textile webs. The light weight, softness, and the low cost of such webs are some of the characteristics which make them useful as replacements for the considerably heavier and less flexible cottonA gauze materials. The major drawback to the use of nonwoven webs has, of course,been their inherent lack of strength, when compared with a woven material of the same weight per unit area.

The strength of a nonwoven web in a given direction isV directly related to the `relative number of libers of the web extending in that direction. With conventional apparatus for forming nonwoven webs, the majority of the bers extend generally in the machine direction of the web so that the maximum strength occurs lengthwise of the web and much less strength is obtained in the cross-machine or transverse direction in the web.

For many applications of nonwoven web structures, it is important that the transverse strength of the web be comparable to, or even greater than, the strength in the machine direction. One practical means for accomplishing this result is to provide a laminated structure in which the fibers of one of the webs are disposed primarily along the longitudinal direction of the web, and the fibers inpan overlying webare arranged substantially perpendicular to the bers in the first web.

Such products are very diflicult to manufacture, especially as a continuous operation, although it should be mentioned that some paperboard cores are made of two plies of paper with the Vmachine directions of the separate plies at an angle to each other. However, because of the method and apparatus employed in combining the paper plies in this product, the finished core results in a dual helix of paper webs in which the maximum strength is neither along the longitudinal rior the transverse axis of the product.

Some other types of equipment have been suggested for making more nearly perfect crosslaid webs. such equipment is usually discontinuous in operation and in any event, operates at an extremely slow speed. The provision of an apparatus for manufacturing such Webs ina continuous and rapid manner is oneof the primary Aobjectsof the present invention; v v v makingl However, i

ice

The present invention is also concerned with the provision of methods and apparatus for making gauzelike web or sheet products from sets of strands which are' laid in a cross pattern one on the other. `Other objects of the invention include the provision of a method'for manufacturing a strengthened nonwoven web in a continuo-us, rapid process, and the provision of novel 'apparatus for continuously laying a cross sheet or apattern of threads onto a moving supporting surface which may also include, a sheet or a patternrof threads, andeforv cross sheet to provide la continuous crosslaid cutting the product.

The invention also includes the provision of certain structural and operational features of great importancei in accomplishing the above stated general objects of 'they invention. i

The present application is a continuation-in-part of my prior application, Serial No. 390,402.9, tiled vNovember 3, 1953,-now abandoned, 1and is assigned to the assignee the sheet, or the direction of the reinforcing strands, i-s` at a substantialand predetermined angle to the direction of movement of the supporting surface, 'to the end that the resulting direction of lay willbe' at an angle, alsoV predetermined, and preferably a right angle to the Inachine direction `of the finished product, and'then continu" ously cutting the second helixlaterally' inV a direction parallel to an edge of the supportingsurface.

Several forms of apparatus for carrying out the abovedescribed method are illustrated in the drawings, in which:

Figure l is a View in perspective ofan laying a sheet material on another sheet;

Figure 2 is aplanview of the' apparatus shown in Figure l; a

Figure 3 is a fragmentary, somewhat enlarged View of the drum and mandrel assemblyv 'of the apparatus illustrated in the preceding figures;

Figure 4 is a somewhat schematic view of the mandrel and the two sheets trained around the mandrel, illustrating the manner inwhich the cross sheet or other medium or other medium;

Figure 5 is an'enlarged, fragmentary mechanism which may be employed;

Figure 6 is an end view of the mandrel in the direction of the mandrel axis; i

'Figure l7 is an enlarged, fragmentary view of a typical completed nonwoven web, the view beingA partially broken away to illustrate the structure of the component plies;

Figure'S is a somewhat schematic drawing of a machine for applying a pattern of threads onto a web;

Figure 9 isa fragmentary View of a gauze-like product which may lbe produced with the machine shown in Figure8;

Figure 10 is a fragmentary view of an overlapped web structure also falling within the scope of the present invention;

Figure ll is a schematic view illustrating the various angular relationships which occur during thecross: laying of the web, thread, or other mediums, one vupon the other;

Figure 12 is a fragmentary view, partially in section, of an improved mandrel construction-having especial utility'in connection with apparatus of the general typel shown in Figures land 8;v

view of a cutting apparatus for Figure 13 is anV enlarged sectional view taken on the line 13-13 of Figure 12; and

Figure 14 is a perspective view of a particular belt construction especially useful in the practice of the invention.

' In Figures 1 and 2, reference numeral 10 indicates generally a frame assembly which supports the various elements in the cross laying assembly. The upper beam sections of the frame 10, indicated at 11, have a pair of angularly disposed shaft supports 12 which tightly engage a shaft 13 extending from a stationary mandrel 14 and hold it against rotation. The mandrel 14 is provided along a portion of its outer surface with a helical, raised rib 16 to serve as a guide means for an endless exible belt 17 composed of canvas or other exible material. The belt 17 is guided onto the surface of the mandrel 14 from a roller 18 and extends between the lands providedV by the rib 16; the width of the belt 17, measured on a line parallel to the axis of the mandrel 14,' is slightly less than the pitch of theV helix provided by the rib 16.

.Forv most types of webs, it will be desirable to use a belt of this nature in guiding the web around the mandrel, but the presence of the belt may not be required for webs which can conform to the mandrel surface without breaking upon the application of suflicient force to pull the web about the mandrel. Y

The belt 17 makes at least one complete turn about the stationary mandrel 14 and then is trained over a driven roller 19. The latter has a shaft 21 supported by a block 22 slidably received within a slot of a bracket 23 carried by the frame 10. Movement of the block 22 within the slot thus provides a means for adjusting the tension of the belt 17. The belt then passes over a roller 24 having a shaft 26 supported within a block 27 also slidably received in the slot in the bracket 23. The relative position of the roller 24 with respect to the roller 19 can be adjusted by movement of a rod 28 attached to the block 27.

The belt 17 after being trained around the roller 24 passes over a guide roller 29 located centrally of the frame 10, and is then trained around a roller 31 located near the base ofthe frame 10. The belt is then passed lengthwise of the machine and may be given a half twist so that it can be trained around a vertically disposed tension roller 32 (Figure 2).

The belt 17 is then trained around a second vertical tension roller 33 after which it is given another half twist. The belt is then received about a guide roller 35 and tinally passes over the roller 18, completing its oop.

As the belt 17 is moved along the mandrel 14 in the illustrated structure, it carries with it a longitudinal web or sheet medium 36. This may comprise a sheet of paper or nonwoven fibers, as illustrated, or it may comprise threads, or other material. The medium 36 is conveniently deposited on the belt 17 from a suitable supply means, such as the roll of sheet material illustrated at 37 in Figures l and 2, and the apparatus desirably includes a suitably disposed roll 38 for guiding and slightly tensioning the sheet 36 or other medium as it is deposited on the upper surface of the belt 17. The axis of the illustrated supply roll 37 is parallel to the axis of the belt guide roll 18, and the supply roll 37 is conveniently disposed a short distance above and to the rear of the belt guide roll 18.

In the illustrated embodiment of the invention, the width of the sheet 36 is comparable to the width of the belt 17 and when the sheet 36 is of nonwoven material, the fibers in the sheet 36 will lie predominantly in the machine direction, i. e., lengthwise of the sheet, so that the maximum strength of this sheet is along its long dimension.` Rollers can be provided for pressing the sheet 36 onto the belt 17, or adhesive. spots may be employed on the sheet for holding it on the belt, but ordinarily these are unnecessary, as a thin, nonwoven web will readily be guided by the surface of a canvas belt.

The mandrel 14 is disposed with it axis substantially coincident with the axis of a hollow rotating carrier 39, comprising a pair of end tlanges 41 and 42 separated by means of spacers 43. The rim of the carrier 39 is mounted for rotation on a set of four wheels 44 (Figure 1) which are supported for rotation on a bracket 46 secured to an intermediate portion of the frame 10.

The carrier 39 has a pair of angularly disposed support brackets 47 and 48 (Figure 2) which journal a shaft 49 for rotation therein. The shaft 49 carries the second medium which is applied, in crosswise relationship, to the tirst medium during the operation of the apparatus. In the illustrated apparatus, the second medium comprises a sheet 52 of nonwoven fibers which is unwound from a suitable supply roll 51 disposed on the shaft 49. The bers in the sheet 52 extend predominately along the length of the sheet so that the maximum strength of the sheet is in that direction.

The sheet 52 passes over a guide roller 53 and is then wrapped around the main sheet 36 carried by the belt 17 (Figures 3 and 4). If desired, small spots of adhesive can be provided on the sheet 52 to hold it onto the sheet 36 until the combined sheets leave the machine. The angular positions of the roll 51 and the roller 53 are quite critical, and the support mechanism for the

members

51 and 53 should be adjustable. When laying one web upon another, or when laying a series of cross webs to produce products of the type shown in Figure l0, freedom from distortion will be achieved only if the sheet 52 is trained about the mandrel so that the sheet 52 intersects the sheet 36 (or the belt 17) along a continuous straight line of intersection extending the full Width of the sheet 52. Thus, the sheet 36 in being pulled across the mandrel 14 forms a helix which moves about the mandrel 14 in a counter-clockwise direction as viewed from the end of the carrier 39 at which the sheet 36 enters. At the same time, the relative movement between the roll 51 and the mandrel 14 resulting from the rotation of the carrier 39 about the mandrel 14, which rotation is also counter-clockwise, as viewed from the end of the carrier at which the sheet enters, wraps the sheet 52 in another helix which intersects the helix of the sheet 36 at right angles thereto.

When using the particular apparatus shown in the drawings, the same angular relationships will be observed where the sheet 52 is replaced by a plurality of threads or other strands, i. e., the points of tangency of the strands as they are trained labout the helically moving sheet 36 will define a straight line parallel to the axis of the mandrel. However, the laying of threads upon webs or other threads permits a considerably wider variation in the parameters of the process, and these will be discussed in a subsequent portion of this specification.

After the crosswise reinforcing medium, whether of threads or of sheet material, has been applied to the medium trained about the mandrel, the sheet 36 in the structure of Figures l and 2, the crosswise medium, the sheet 52 in the illustrated structure, is continuously slit by means of a slitting device S4, best illustrated in Figure 5 of the drawings. As seen in that drawing, the slitting device 54 may comprise a small motor 56 which drives a shaft 57 upon which a disc cutter 58 is secured. The edge of the disc cutter 58 is positioned so that it cuts the laminated sheets at oneedge of the main sheet 36, parallel to the marginal edge of the main sheet 36. The edge of the disc cutter 58 extends into the small space provided between the belt 17 and the rib 16, as shown. The cutting means 54 is secured to a stationary part of the frame 10 by means -of a support arm 59 (Figure 3).

A common drive system is employed to pull the belt 17 across the mandrel 14 and to rotate the carrier 39. This drive system may include a variable speed motor 61 which drives a variable speed transmission 62 through s a chain and sprocket assemblyf63 (Figure 2).` The output shaft of the transmission 62 operates a speed reducer (not shown) which in -turn is coupled to a sprocket 64 (Figure 1) by means of a chain 66 to 'drive the roller 19.

The energization of the motor 61 is controlled by means of a motor control unit 67, electrically connected thereto. A hand operated control 68 (Figure 2) provides a means for adjusting the input to the motor. The `shaft of the motor 61 also is coupled to a speed reducer 69 by means of a chain and sprocket yassembly 70 (not shown in detail), and the output of the speed reducer 69 is coupled by means of a sprocket and chain assembly 71 to a shaft 72 to which a beveled gear 73 is secured. The beveled gear 73 engages an annular gear 74 concentric with the end flange 41 of the drum `39 to rotatethev carrier 39 about an axis substantially coinciding with the axis of the mandrel 14. i

The means for pulling the belt across the mandrel 14, as well as the -means for driving the carrier 39 illustrated in the drawings, represent only one possible drive system which may be employed, and it will be recognized that various means could be provided to accomplish the same results. n

A linished web, as it is delivered by the machine in the vicinity `of the roll 19, is 'illustrated in Figure; 7"of the drawings. As seen in this gure, the underlying sheet 36 has a signilicant proportion of its fibers aligned in the longitudinal direction of the web, and the cross sheet 52, of slightly greater width than the sheet 36, has its fibers predominantly in the' direction perpendicular to the direction of the longitudinal libers in the sheet 36. The laminated web structure can be printed in spaced areas with suitable adhesives such as vinyl polymers, polyethylene, and the like in order to further increase the strength of the laminate according to any of a variety of processes.

A modified form of the invention is illustrated in Figure 8 of the drawings. In this embodiment of the invention, which is especiallyl adapted to the manufacture of cross laid thread products, such as are'illustrated in Figure 9, or to products which combine sheets and reinforcing threads, means are provided to apply a pattern of. threads ina network over a moving web or other medium.- As

seen in Figure 8, `a sheet 81 which maybe a sheet of` nonwoven fabric or other sheet material, is received under a roll 82 whereupon it is guided. onto the surfaceof a moving belt 83 bymeans of a roller 84; As .thesheet 81 and the belt 83 move to the right as seen in Figure 8,

the sheet 81 is overlaidwith a pattern of longitudinalil threads 86 which are being constantly supplied from a creelt 87. The thread cones included in the creel 87 supply a plurality of series of threads 86 which pass through a plurality of guide means 88 arranged to direct the threads over a iirst guide bar 89 and about a second horizontally disposed guide bar 91. The threads 86 then pass overa comb array 92, following which the threads are given a coat of adhesive from an applicator roll 93 in contact with the threads. VA suitable adhesive such as a thermoplastic resinons composition is applied to the surface of the applicator roll 93 from a roll 94 in=contact therewith. v

After the threads 86 have received a coating of adhesive, the thread reinforced web and the belt83 Ycarrying the web .are guided about a stationary, cylindrical mandrel 96 so Yas to form thereon a'lirst helix, as shown.

The belt 83, of course, is continuously pulledl about the` stationary mandrel 96 by means not shown in the drawings.

The mandrel 96 issubstantially coaxial with a. rotating carrier or disc 97 which applies threads to the moving web in a direction normal to the direction of the previously applied threads. In other words, the carrier 97 is arranged to wrap additional threads in the form -of helices at right angles to the helices. formed by the previously deposited threads as those threads'pass about the mandrel. The points of contact in the illustrated em bodiment form equally spaced points on a right circular section of themandrel, instead of the straight line of'- intersection described in connection with the previously described embodiment; As previously pointed out, the

line of intersection in the case of thread laying may vary' considerably depending upon the manner in whichv the threads are received on the supporting surface.

The carrier 97 supports a plurality of circumferentially spaced cones vof. thread supported on both sides thereof..

The cones 98 feed threads 99 centrallyv of the carrier disc 97 and over an annular series of guide means 101 -ontoy the surface of the moving belt or sheet; l .As the belt 83 is removed from the mandrel, a slitter 102 engages the web to sever the Vcross strands parallel to the marginaledge of the moving sheet.A 1-

The resulting thread reinforced product-is then separated from the belt 83, the belt V83`passingr over a .series of.rollers,.including rollers 103 :and 104, before returning- The'thread reinforced` to theinlet end yof the machine. product may be then passed about a` heated roller 106 in contact with a heat resistant roller 107 in order to cause the adhesive applied to the strands to become more plastic and to flow about the junctions of the longitudinal and transverse threads. With certain type of adhesives,` a better bond is thereby secured between thevweb 'and-1 the pattern ofl threads, but the use of a heated roll orV rolls is optional.

After leaving the surface of the roll 107, the completed product willnormaly be conveyed, as by the roll 108, to"

a slitting means 109 where the web will be cut into' any desired width. After leaving the slitting means 109, the

web strips are wound about a take-up reel 111`by means of a pair of winding

rolls

112 and 113. t

It will be appreciated that various 'other mechanical means such as gears, belts, chains, discs or the like may be employed to carrythe cross laid material on a path which is coaxial with the axis of the mandrel.

More than one layer of sheet material. may be embodied into the finished product. For example, an ad-I ditional sheet or web, ora series of sheets or webs, may

bev applied to the upper surface of the threads 86, and'l the underlying sheet or sheets, at any convenient point` prior to the application of the threads 99. Similarly,

additional sheets, or even additional sets of longitudinallyt extending threads may be applied to the product'after the application of the cross threads 99. f

Also, the web or sheet components may be omitted entirely, this resulting in the the thread-only product, which has particular utility in instances where woven products such as gauze have heretofore been used, consists merely in theV two sets 'f of strands adhesively attached to each other at at least somel of their junctions.

For some applications, it is important that the strength of a product in its short dimension be as great as,1 or greater than, its strength in its long dimension.' f A typical example of a product of this type is a boxmakers 'tape' which is used to join the edges of a corner of a cardboard box. This type of product can be made lon a machine of the type illustrated in Figures 1 -and 2 by eliminating the main sheet 36 and providing twoor more rolls of paper or other material in circumferentially spaced relation within the carrier 39. The resulting productis illusproduction of a product of the type illustrated in Figure 9. As shown in that ligure,

i Turningnow to the schematic showing in Figure ,11, the distances shown are identified as follows:

AB -is the effective width of the belt on a line parallel to the axis of the mandrel, this distance being equal to the pitch of the helical rib 16;

BD is equal to the circumference of a right circular section of the mandrel (simply the circumference of the mandrel if no belt is employed, or the outer circumference of the belt as it is trained about the mandrel);

BG is the effective Width of the belt measured along a line perpendicular to its length (or the width of the sheet if no belt is used);

' AD is the length of the helix, comprising one complete turn from a point B around the mandrel to point A;

CF is the transverse width of the cross sheet;

'ACD isthe repeating length of the cross lay pattern, measured along the length of the main sheet for the condition where the carrier makes one revolution for each vadvance ofthe sheet through the distance CD;

i AE `is the opening available for cross laying, i. e., the available space on the main web on which the second web lcan be laid, and l i a is the angular deviation between the direction of longitudinal movement of the second web and a perpendicular to the direction of longitudinal movement of the first web, i. e., the angle between the edge of the second web or other medium and a perpendicular to the'edge or direction of movement of the rst web, when the second web is lin position on the iirst web; and

is the angle `between the mandrel axis and the direction of longitudinal movement of the rst web or other medium. This angle is also the angle of inclination of the edge of the supporting belt (or the rst medium, ifY thatmedium be of sheet material) to the line along which the belt (or the first medium, if that medium be of sheet material) intersects the mandrel.

Normally,l the width of the main sheet and cross sheet, and the 'angleof the lay will be predetermined, and the factors to be determined will be the inclination of the main web to the-mandrel, the diameter of the mandrel, and theratio lof belt speed to the speed at which the cross laid` material is applied to the mandrel. There are' practicallimitations in the design which must be taken into consideration. For example, if the angle of inclination of the supporting surface tothe line of its intersection with the mandrel, angle 6 in Figure l1, is too large, the pull on the belt will be taken up along the mandrel and not by the belt. If the angle is too small, the belt will slip off the mandrel. For practical perpendicular cross laying, this angle will be in the range of from .to 60.

" For satisfactory operation at high speed, it will be found important to provide special support means for the belt, or rst medium, as that element-is moved on the surface of the mandrel.V In the particular apparatus illustrated in the drawings, that support is provided .by an air cushion formed intermediate the inner surface of the belt or first medium and the outer surface of the mandrel. This will be described in further detail in connection with Figures 12, 13 and 14,

. In the following analysis, it is assumed that the carrier for the cross laid medium makes one revolution for each repeating length of the cross lay pattern, represented by the length CD in Figure 1l. Those skilled in the art will appreciate that other speed relationships are possible the practice of the present invention.

yFrom anV inspection of the angular relationships and the 'application of the law of sines, it will be seen that:

B G V cos B--BD (1) C'F=C'D cos a (2) .BG-:30me a (3) Applying the law of sines:

CD BC' sin (0-a)- cos 6 Multiplying both sides by cos a and using Equations 2 and 3:

so that the angle 6 may be calculated from the two web widths and the angle between the webs.

It will further be seen that:

AE=AC cos a (7) Applying the law of sines:

AC' BC sin (-0-l-a) "sin 0 Ac=Bo.- OS (0) (s) sin 0 Multiplying both sides by cos a, and substituting Equations 3 and 7:

cos (0-a) Equation 9 gives the opening available for cross laying. If the distance AE is less than the distance CF, then the cross web must be split up into increments, and applied e in sequence, or the opening increased by wrapping the belt another turn about the mandrel.

In the case of laying individual threads, instead of a cross web, it will be seen that if N threads equally spaced by a distance S are employed, Equation 6 will become:

l-I-BG sin a tan 0: BG cos a The following specific examples illustrate the application of these equations to specific cases.

Example I tan 0 (BG COS or) BG sin oz S tan 45[(40+0.5) cos 0]-(40+0.5) sin 0 0.2 v

Y N Y=i2'o`2.5 Strands rlvForconvenience;N-will betaken as 200.

'would be:

The angle 6 is then calculated for the Equation 10 as follows:

valueof from tan a: =0.9s765 Y The effective diameter, D, of the mandrel. (actual diameter plus twice the thickness of the belt) mayV then be calculated from Equation l:

BG 'lr COS/0 j Y Dfi- 18.11.9111.

Diameter of mandre1=1s119 inf-@5517.619 in.

i Example` Il LFor producing the same product as specifedqin Example* I, butfwhere the angle 0 between the -main sheet y andthe mandrel is to be about 60, `the following values are obtained:

to be 0.5 inch4 as previously.

Using Equation 6:

tan 0: :1.7284

Ulla i' l tan 0-405- 098765 Solving for the mandrel ldiainetertrumV Equation Diameter of mandre1=l8.1l9- 0.y5=17.619 in.

lThe available opening in this case from Equation 9 fSince this value exceeds the width-ofthe cross web, the

ldesired product can be obtained byusing a single roll of the cross web.

Example IV In this case, a cross web measuring 70'inches in width lwas to be laid at right angles tol a main web 40 inches in width, using vthe same ribwidth and belt thickness as pre- The mandrel diameter is then' calculated as' followsz" l0-5. :25.742im.

1r COS 6 Diameter=-742-0.5=25.242 in.`

The available opening, AE, is then calculated as follows:

Aar-S-aazlar, in.

sin 0 Since the available opening is slightly more than onethird the width of the cross web, the cross web would have to be laid in at least three parts,.as by slitting the 70 inches web into three equal strips, and laying them in -side-by-side-relationship along the main web as it.

moves about the mandrel.

Example V It was desired to use a sheet 40 inches wide, va rib 0.5' inch wide, a belt 0.025 inch thick, a spacing of 0.2 inch; The de between threads, and a cross lay angle of sired angle of intersection (angle 0) was about 45.

The distance CF in Figure 1l in the case of strands is-` represented by the repeating width of the cross lay...

Hence from Equation 5: v y I sin 45-30) 0.2N-(40+0.5) W

Choosing the convenient valueof =75, the repeating width of the cross lay is then 0.2=15 in.

l5-H405) sin 30"k r tall -m--LOO5O and i The diameter, D, is then obtained from Equation 1::

1r COS 0 The actual diameter of the mandrel is then As previously indicated, the above examples are prodicated upon the use of a specific speed ratio between the In the case of thread laying, the speed relationships are usually supporting surface and the cross laid medium.

the easiest to vary in order to* change the angle of inclination ybetween the two surfaces. The following example illustrates the eiect of speed variation.

Example VI A A With the Vsame equipment as employed in Example I, thehcarrier made one revolution for every 40 inches ad- Vance ofthe web material. VAssume now that the carrier is to make n revolutions for each 40 inch advance of the web. Wirth this condition, it will be seen that the repeating length of the pattern will become:

40/n inches VReferring again toiFigure 1l, it will be 4observed that.

in this situation:

UniG-D and:

Y y f GD GG GD- CD;GD.".(T

rEquation 10 can be solved for tan 6 exactly as fol-4 f .35 lows:

thefeferebe? G D) t fthe spacing in the originalexample, the formula for the'newspacing may be written;

i New spacing-1,(originalspacingyoixv (13) To illustrate -theabove' with speciiic'examplesg'as'- sume that the carrier makes two' revolutionsfor "every 40 inch advance of the web in Example I. From Equation 12:

Assuming next that the carrier makes one-half a revolution for each 40 inch advance;

GD tain CIT- l B G- In the special case where n,=J/z, itpwill be seenfrom Equation 12 that a=0. eos 44 38.6

Upon consideration of the several foregoing examples, it will be apparent that the following generali relationship exists: v

n;1 n(CD) (n-l') (CD) n BG BGV in which equation n is equal to the number of turns of the second medium which occur during each linear advance of the rst medium, in the direction of movement of that medium, equal tothe transverse width of the second medium, and the Aotherquantities are asjdened in the foregoing.

-It will also be apparent that thethread spacing S, in instances where the second medium comprises a series of longitudinally-extending threads, may1 be determined by the following formula:

Shaw

in which equation N is equal to the number of threads comprising the second medium,V and the other quantities are as defined previously. As previously indicated, satisfactory operation of equip;V ment of the general type described in the foregoing requires thatfthe support belt, or the medium which is trained abqutthe mandrelininstances Y where ,a belt is 'tan a: (145)A not used, shall move freely about the mandrel. This is especially, important in the high speed oper-ation of equipment using a support belt for the medium which is carried on the mandrel, as for example, during the manufacture of crossedthread products of the general type illustrated in Figure 9.

The only effective means so far devised for assuring free movement of such a belt involves the provision of a cushion: of..air which floats the belt a short distance aboveuthe mandrel surface, anda mandrel designed 4to operate in this manner is illustrated in Figures 12 and 13. It will be understood that the air-flotation type mandrel is suitable for use in apparatus of the type illustrated in Figures 2 andv 8, as well as other embodiments in accordance with the invention. It will also be understood that it may be advantageous, in certain instances,

' and the counter-sinking was at an angle of 118.

to use an air cushion or air otation mechanism in conjunction with one or more of the supporting guides for the belt structure in thos'e mechanisms which utilize a belt.

Themandrel 119 illustrated in Figures 12 and 13v includes Vva suitable'tubular shell 121 of cylindrical form, which is closedat either end by an annular plate member 123, welded or otherwise affixed to the shell 121. If the mandrel 119 is intended for use in place of the mandrel 14, it 4may include shaft sections 125 which extend axially therefrom; these may be provided by,a single, continuous shaft, or two stub shafts may be used. The outer Isurface of Athe tubular shell 121 is provided with a helical groove '127, similar to the mandrel 14, within which there is located a spline or key member 129, which serves as a guide means for defining the path of movement of thev belt'over the mandrel surface.

In structures embodying a supporting belt, the spline member 129 should project from the surface of the shell a distance approximately equal to the thickness of the belt. The surfaces of the belt and the spline are desirably polished, and may be plated with chromium or other metal, to provide a very smooth, anti-friction surface.

'lfhe walls of .the shell 1 21are provided with a series cedflcounter-spnk' openings 131, which communica .withjthe interiojrjof the shell. In a particular structure which ha's'proven'especially satisfactory in use, the mandrel shell had a length of approximately '1 20 inches, and a diameter of 12.375 inches, this mandrel being adapted tosupport a belt having a width of 27 inches which was trained about the mandrel to provide 2 completely supported turns of the belt. The holes had a diameter of IAS inch, and were spaced approximately 3% inches apart, uniformly on the mandrel surface, so as to underlie' the belt in positionthereon.'

In the mandrel having the dimensions stated above, there were 358 holes-in the region of the mandrel engaged by the belt. The counter-sinking provided a maximum diameter at vthe outlet end ofthe holes of 1/sjinch,

During operation, pressure airwas `admitted to the interior of the mandrel so as to maintain the pressure inside the mandrel within the range of from about 3-5 lbs. per square inch, gauge. A single air inlet, such as illustrated at 133 in Figure 12,l is satisfactory for this purpose. Underthe stated conditions, air will escape through the counter-sunk, /airjdi'scharge openings 131 in' sufficient This will reduce the friction between the belt and the l:mandrel to a very low value, and, as previously noted,y

the belt or the web medium. Also, when using the air` flotation mandrel in conjunctionwith a supporting belt of porous material, itis of some importance that one surface of the belt; usually the outer surface, shall include a relatively non-porouslayer. This may, for example, be a layer of polyethylene, tetrafluorethylene, or other .suitablerriateri'al, ad'hesively attached to Ythe belt surface. This"noir-porous"layerfespeciallywhen it constitutes the outer layer and is made of a material such as polyethylene, ,orptetrafluorethylenq performs 'a dual function. First, it facilitates the removal of the thread or other medium which ,is applied to-the belt `during operation of the apparatus, and in addition, it aids, in conjunction with the porous under layer, in accomplishing even flotation of the`belt on the` mandrel. One example of such a belt is illustrated at 135 in Figure 14, in which view the porous layer of the belt is shown at 137 and the non-porous layer at 139. It will be understood that this belt can be substituted for the

belts

17 and 83 of the previously described structures.

In the foregoing, I have disclosed the features of a new, improved method and apparatus for manufacturing a Wide variety of cross laid and reinforced products involving the use of mediums which may comprise sheet material of the woven, non-woven or felted type, in combination with other materials of this type or with threads. The invention also makes possible the manufacture of gauzelike materials, having characteristics equal or superior to woven textile materials, at higher speeds, at lesser cost, and with a number of important advantages as compared with woven products. Any types of thread made from natural or artificial fibers or filaments, or combinations thereof, may be used.

I have also set forth in the foregoing variou-s of the important mathematical relationships which exist and which should be followed in the most efficient practice of the invention. In addition, I have disclosed certain mechanical arrangements and structural combinations of especial advantage in carrying out the invention.

Various features of the invention believed to be new are set forth in the accompanying claims.

I claim:

l. An apparatus for forming a continuous web product, comprising a mandrel, a flexible endless belt having at least one complete helical turn on said mandrel, means for depositing a first, elongated flexible medium on said belt, said first medium being carried by said belt about said mandrel, a rotatable carrier having an axis substantially coinciding with the axis of said mandrel, supply means for a second, elongated flexible medium mounted on said carrier, means for guiding said second flexible medium from said supply means over said first flexible medium while said first flexible medium is passing over said mandrel, the second flexible medium being applied in the form of a helix which is wrapped around said rst medium in such relationship that the long dimension of said second medium is maintained at a uniform, substantial angle to the long dimension of said first medium in the region where the mediums intersect, and means for cutting said second medium transversely of its long dimension after said second medium has been applied to said first medium.

2. An apparatus for forming a continuous web product, comprising a mandrel, a narrow, elongated guide strip attached to said mandrel and defining a helical path around said mandrel, a flexible endless belt having at least one complete helical turn on said mandrel, a portion of said belt being within said helically disposed guide strip and guided thereby, means for depositing a first, elongated flexible medium on said belt, said first medium being carried by said belt about said mandrel, a rotatable carrier having an axis substantially coinciding with the axis of said mandrel, supply means for a second, elongated flexible medium mounted on said carrier, means for guiding said second flexible medium from said supply means over said first flexible medium while said first flexible medium is passing over said mandrel, the second flexible medium being applied in the form of a helix which is wrapped around said first medium in such relationship that the long dimension of said second medium is maintained at a uniform substantial angle to the long dimensionofsa'id first mediumiin the region where the mediums intersect, means for-cutting said'se'cond medium trans-Y verselyoffits long dimension after said second medium has-been applied to said first medium, and means includingwa -source of `pressureair and-aplurality of airl discharge openings providedin said mandrel for providing a cushion of airintermediate said -belt and said mandrel duringoperation-ofsaidapparatus, said belt being. of multi-layer construction and including at least one layer of non-porous material.

3. An apparatus for forming a reinforced web which comprises a mandrel, guide means on said mandrel, a flexible endless belt trained in a helical form on said mandrel and guided thereon by said guide means, means formoving said belt along said mandrel, means for depositing a sheet along said belt with the machine direction of said sheet lying substantially lengthwise of said belt, said sheet being carried by said belt about said mandrel, a carrier having its axis substantially coinciding with the axis of said mandrel, means for feeding a plurality of strands from said carrier about said sheet while said sheet is in a helical form with the length of said strands being angularly disposed with respect to the machine direction of said sheet, guide means arranged to lay said strands in straight lines across said sheet, means causing relative movement between said carrier and said mandrel, and cutting means for cutting said strands lengthwise of said sheet after said strands are laid over said sheet.

4. An apparatus for forming a reinforced web product having plies thereof with the direction of maximum strength of one sheet being in angular relationship to the direction of maximum strength of another of the constituent sheets comprising a mandrel, a flexible endless belt having at least one complete helical turn on said mandrel, means for moving said belt about said mandrel, means for depositing a first sheet on said belt, said sheet being carried by said belt about said mandrel, a rotatable carrier having an axis substantially coinciding with the axis of said mandrel, a roll of sheet material carried by said carrier, means for guiding the sheet from said roll over said first sheet while said first sheet is passing over said mandrel to provide a line of tangency between said sheets which is generally parallel to the axis of said mandrel, and means for cutting said second sheet after said second sheet has been deposited on said first sheet.

5. An apparatus for forming a reinforced web product comprising a mandrel, a flexible endless belt having at least one complete helical turn on said mandrel, means for moving said belt about said mandrel, means for depositing a first sheet along said belt with the line of maximum strength of said sheet lying substantially lengthwise of said belt, said first sheet being carried by said belt about said mandrel, rotary means associated with said mandrel, a roll of sheet material carried by said rotary means, said roll being oriented to apply a second sheet onto said first sheet in a manner such that the direction of maximum strength of the second sheet is substantially at right angles to the direction of maximum strength of said first sheet, means fo-r rotating said roll about an axis substantially coinciding with the axis of said mandrel, and cutting means operable to cut said second sheet continuously after said second sheet has been deposited on said first sheet.

6. An apparatus for forming a laminated web product Y material carried by said carrier in spaced relation to Vsaid mandrel, said roll'being angularly disposed with respect to said mandrel to apply on said rst sheet, a web of sheet material whose machine direction is substantially at right angles to the machine direction of said first sheet withthe second sheet intersecting said first sheet along a line which is generally parallel to the axis of said mandrel, and cutting means operable to cut said second sheet continuously after said second sheet has been deposited on said-rst sheet.

References Cited in the le of this patent UNITED STATES PATENTSv Brennan ...e Sept. 30, 1919 Angier Mar. 2, 1920 Parker Feb. 5, 1935 Rowe Sept. 3, 1940 Smith et al Aug. 13, 1946 Malmstrom Aug. 21; 1951 Jackson .f Dec. 7, 1954