US 3829339 A
Description (OCR text may contain errors)
Aug. 13, 1914 1.. A. PINETTE 3,829,339
METHOD AND APPARATUS FOR FORMING FINE MESH NONWOVEN WEB Filed Oct. 5, 1972 5' Sheets-Sheet 1 L. A. PINETTE Aug. 13, 1914 METHOD AND APPARATUS FOR FORMING FINE MESH NONWOVEN WEB 5 Sheets-Sheet 2 Filed Oct 1.. A. PINETTE 3,829,339.
METHOD AND APPARATUS FOR FORMING FINE MESH NONWOVEN WEB Aug. 13, 1974 s sheets-sheet 3 Filed Oct.
Aug. 13, 1974 PINETTE 3,829,339
METHOD AND APPARATUS FOR FORMING FINE IIESH NONWOVEN WEB Filed Oct. 5, 1972 5 ShQBtS-Shet l.
e2 L/ fl 68 /65 :51 NM 7' $3 I\ 7 Aug. 13, 1974 v .-A. PINETTE 3,329,339
umuon AND APPARATUS FOR rename mm ussa uonwovnn WEB Filed Oct. 5, 1972 s Sheets-Sheet 5 lol United States Patent Olfice 3,829,339 Patented Aug. 13, 1974 US. Cl. 156-179 22 Claims ABSTRACT OF THE DISCLOSURE Disclosed is a method and apparatus for producing a nonwoven web comprising two parallel conveyors each of which supports a set of mounting pins wherein each pin is bent to form vertically and horizontally displaced upper and lower yarn retaining portions. A first reciprocating yarn applicator shuttle with a plurality of nozzles loops individual yarn strands around the lower yarn retaining portions to form a web. A second shuttle likewise forms a vertically and horizontally displaced web around the upper yarn retaining portions. The nozzles on the first shuttle are bent to facilitate passage thereof between the upstanding pins and the two webs are laminated to form a single web of a finer mesh.
BACKGROUND OF THE INVENTION This invention relates to a method and apparatus for producing a fine mesh nonwoven web in a continuous strip and, more particularly, to production of the web and the lamination thereof into an adhesive coated reinforced tape.
For many years nonwoven open mesh webbing has been produced by methods and apparatus similar to that disclosed in US. Pat. No. 1,211,851 issued to Howard on Jan. 19, 1917. Howard disclosed forming a web by advancing two rows of upstanding pins and swinging a plurality of nozzles in a rectilinear horizontal plane laterally from outside of one row to outside the other row, the plane being above the level of the tips of the pins. To loop the strands delivered by the tubes alternately around the pins, a section of the pin carrier was periodically raised above the normal level thereof so the pins would intercept the strands on their inward lateral path.
Subsequently, in US. Pat. No. 2,812,797, issued to Estee on Nov. 12, 1957, apparatus was disclosed that maintained the pins at their normal level, but swung the nozzles in a curvilinear path laterally from outside of one row to outside of the otherrow of pins. To loop the strands delivered by the nozzles around the pins the looping mechanism caused the nozzles to dip downwardly at each end of the stroke to below the level of the pin tips so that the pins intercepted the strands on their inward lateral path.
Later refinements in the equipment, and particularly in the synchronization between the pins and nozzles, permitted the construction of apparatus wherein both the pins and the nozzles remained in a single horizontal plane. At the end of each stroke, each nozzle passed between two pins and reversed direction while outside of the net forming area and returned through another space between pins thereby looping a strand around a pin. It is this method that is commonly in use today.
Today, many uses for the netting require increased strength. One method of providing a stronger webbing, that of forming with thicker, stronger yarn, has been generally unaccepetable inasmuch as thicker yarn is harder to form at a high rate of speed and thicker yarn, coupled with large interstices, provides a laminate with nonuniform strength characteristics. Thus interest has been focused on providing a finer mesh formed from a greater number of fine yarn strands. A satisfactory web can be provided by reducing the spacing of the pins. However, this method has a serious disadvantage inasmuch as the nozzles must pass through substantially smaller spaces between pins and thus the apparatus must be run more slowly.
Recent experiments have formed two separate nets and combined them thus forming a single net. If the two nets are juxtaposed properly with the yarns of one net by bisecting the interstices of the other net a substantially finer net is provided. However, the previously disclosed apparatus for practicing this method is essentially two complete net forming machines and thus is quite complex. See for example, US. Pat. No. 3,607,565 issued to Baton on Sept. 21, 1971. In addition, assuring proper juxtaposition is difficult and, in the apparatus disclosed by Eaton, costs are increased due to excessive wasted yarn that must be cut from the edges of the laminate.
The object of this invention, therefore, is to provide a method and apparatus for producing a continuous strip of nonwoven mesh material, or a laminate containing such a mesh, at a high rate of production wherein the mesh is composed of relatively fine yarn strands defining small interstices.
SUMMARY OF THE INVENTION This invention is characterized by a method and apparatus for forming nonwoven open mesh netting in a continuous strip. The apparatus comprises a forming section with two parallel endless belt conveyors that support upstanding pins. Each pin is bent to form first and second yarn retaining portions that are parallel but vertically and horizontally separated. A first reciprocating applicator, driven by a motive apparatus, receives a plurality of yarn strands from a source of supply thereof and wraps them around the first yarn retaining portions of the pins so as to form a first nonwoven open mesh netting. Similarly, a second applicator receives a plurality of yarn strands and, in conjuction with the second yarn retaining portions, forms a second open mesh netting. Due to the aforementioned displacement of the first yarn retaining portions from the second yarn retaining portions, the first netting is vertically and horizontally displaced from the second netting. Combining apparatus forces the two nettings together in a vertical direction so as to eliminate the vertical displacement, leaving only the horizontal displacement. Thus the result is a single open mesh nonwoven netting with substantially smaller interstices than either the first or the second netting. Proper juxtaposition is assured inasmuch as both nets are formed on the same set of pins. In addition, since each pin effectively replaces two conventional pins, they are well separated and the nozzles pass easily therebetween so the netting can be produced at a high rate of speed. Consequently, thenecessity of choosing between highly complicated equipment or slow rates of production has been obviated.
A feature of the invention is the utilization of offset nozzles in the applicators. The upstanding pins can be, bent so that the horizontal displacement between the first yarn retaining portion and the second yarn retaining portion is transverse to the direction of motion of the conveyors or parallel thereto. Either configuration facilitates the production of fine mesh nonwoven netting. In either configciprocating applicators is simplified and higher production rates are possible.
Another feature of the invention is the expansion of this technique to a three tier apparatus. That is, a pin comprising first, second and third yarn retaining portions is utilized and a third reciprocating applicator mechanism is added. Thus, yet a finer mesh netting can be produced at a high rate of production by combining three nonwoven webs.
Yet another feature of the invention is the inclusion of a laminating apparatus so that the nettings can be incorporated into a laminate if so desired. For example, the netting can be laminated between two strips of kraft paper and an adhesive can be applied to one side of the laminate thus forming a reinforced packaging material.
DESCRIPTION OF THE DRAWINGS These and other features and objects of the present invention will become more apparent upon a perusal of the following description taken in conjunction with the accompanying drawings wherein:
FIG. 1 shows a portion of a laminate comprised of two sheets of paper or the like and reinforced with a nonwoven open mesh netting that is manufactured in accordance with the subject method;
FIG. 2 shows the superimposition of two nonwoven open mesh nettings formed around alternate pins of a forming apparatus;
FIG. 3 shows various methods of looping yarn strands around the upstanding pins;
FIG. 4 is an elevation view of a preferred open mesh nonwoven web forming apparatus;
FIG. 5 is a detail of a preferred nozzle and pin combination wherein the pins comprise first and second yarn retaining portions;
FIG. 6 shows the pins of FIG. 5 in conjunction with shorter nozzles for applying yarn to the second yarn retaining portions;
FIG. 7 shows a conventional upstanding pin and nozzle combination for comparison with that combination shown in FIGS. 5 and 6;
FIG. 8 shows an alternate preferred pin and nozzle combination with straight, inclined nozzles;
FIG. 9 shows another pin embodiment wherein the pins' are bent in a direction transverse to the direction of motion of the conveyors;
FIG. 10 is a sectional view taken along the line 10-10 in FIG. 9 that shows the nozzles utilized in conjunction with the pins shown in FIG. 9; and
FIG. 11 schematically shows still another preferred pin and nozzle combination wherein the pins comprise first, second and third yarn retaining portions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring first to FIG. 1 there is shown a section of a laminate 21 comprising an upper sheet 22 of paper or the like, a lower sheet 23 of similar material and a nonwoven open mesh reinforcing webbing 24. The laminate 21 is bonded together with an adhesive and, if desired, the underside of the sheet 23 can be coated with a suitable adhesive. Today there is interest in manufacturing a stronger laminate 21, but it has been found undesirable to make individual yarn strands 25 within the laminate 21 substantially thicker inasmuch as that causes stiffness and nonuniform strength characteristics and thus the laminate becomes difficult to handle. In addition, thicker yarns are more costly. Consequently, attention has been directed toward providing a finer mesh, that is, one with smaller interstices 26.
Laminates such as the laminate 21 are generally manufactured by techniques and apparatus similar to those diclosed in US. Pat. No. 1,211,851 issued to Howard on I an. 9, 1917, and its progeny. The mesh as formed by the method of Howard involves looping a plurality of yarn 4 strands, released through individual nozzles, around two sets of traveling, upstanding pins. Generally, the nozzles pass between the pins during the looping operation. In order to provide a [liner mesh, the pins have been moved closer together and thus synchronization between the reciprocating nozzles and the upstanding pins has become more difificult. It is because of this synchronization problem that a laminate 21 with suitably small interstices 26 has not been manufactured at an acceptable production rate.
Referring now to FIG. 2 there is a plan view of a net forming apparatus 31 comprising two parallel rows 32 and 33 of spaced apart upstanding pins 34 and 35. The rows 32 and 33 move in the direction of the arrow AA. A plurality of nozzles 36 are affixed to a reciprocating shuttle 30 that travels in the direction shown by the arrow BB and is driven by a drive shaft 46 connected to a motor (not shown). Thus, the nozzles 36 wrap individual yarn strands 37 around every other pin 34 and 35 forming a nonwoven open mesh netting 38 in the manner disclosed by Howard. Traveling in the direction indicated by the arrow AA, the pins 34 and 35 approach another plurality of nozzles 39 mounted on a reciprocating shuttle 45 that reciprocates as did the first shuttle 30 and is powered.
by a drive shaft 47. The nozzles 39 wrap individual yarn strands 41 (shown as broken lines) around the remaining upstanding pins 34 and 35. Therefore after the pins 34 and 35 have passed the nozzles 39 a second, parallel netting 42 is formed of yarns 41 that are parallel to the yarns 37 and the combination produces a final netting 43 defining smaller interstices 44 than the nettings 38 and 42. Thus it is seen that a finer mesh netting 43 is formed when two nettings 38 and 42 are formed on rows of upstanding pins 34 and 35 wherein the pins supporting each netting are alternated along the length of the rows 32 and 33.
Although this specification refers to two shuttles or, below, three shuttles, it is obvious that inasmuch as the shuttles such as 30 and 45 reciprocate together they can be joined end to end and, it could be argued, form one shuttle. It is to be understood that this modification is considered within the scope of the invention.
Each yarn strand 37 and 41 is wrapped around a single pin 34 or 35. This is shown more clearly in FIG. 3(a). However, it will be appreciated that the nozzles 36 and 39 require a measureable reversal or turnaround time while outside of the parallel rows of pins 32 and 33 to change direction. Only if the reversal is quite rapid will the yarn strands 37 and 41 wrap around a single pin 34 as shown in FIG. 3(a). If the reversal time is longer with respect to the speed of travel of the parallel rows of pins 32 and 33, each yarn strand 37 and 41 will wrap around two pins 34 as shown in FIG. 3(b), or if longer yet, around 3 pins 34 as shown in FIG. 3(c). However, it will be seen on examination of FIGS. 3(b) and (c) that if the yarn strands are wrapped around the same number of pins and the different yarns alternate as shown in FIG. 3, the superimposition that provides the composite fine mesh net 43, as shown in FIG. 2, is not affected. Thus, it is to be understood that although the figures depict a netting 43 being formed with yarn strands 37 and 41 each wrapped around a single pin 34 and 35 the netting can be formed with the strands wrapped around two or more pins.
Referring now to FIG. 4 thereis shown an elevation view of a preferred apparatus 51 for forming non-woven open mesh netting comprising two endless belt conveyor chains 52 (only one of which is visible) supporting a set of equally spaced upstanding pins 53 and spanning between two drive sprockets 54 and 55 which are powered by a motor (not shown). The upper portion of the chain 52 rests on a bar 50 that provides vertical stability. The pins 53 are shown in detail-in FIG. 5 and define a base plane in which two nets are formed. Each pin 53 comprises a first yarn retaining portion 56 and a second yarn retaining portion 57 generally parallel thereto but vertically and horizontally separated therefrom. The pins 53 are bent in the direction of travel of the chains 52. A first applicator shuttle 58 (similar to the shuttle 30, and also driven bya reciprocating drive shaft) reciprocates along guides 59 and supports a plurality of nozzles 61 that each receive a strand of yarn 62 from a separate spool 63 thereof. (To preserve clarity, only one spool 63 is shown.) As shown more clearly in FIG. 5, the nozzles 61 are hollow and are bent so as to pass between the upstanding pins 53 more easily. The applicator shuttle 58 reciprocates (in and out of the paper) to form an open mesh netting 38 like the netting 38 shown in FIG. 2. It will be noted from an examination of FIG. 5 that the nozzles 61 on the first applicator shuttle 58 deposit yarn 62 on the lower yarn retaining portion 56 of the pins 53. A second, similar, applicator shuttle 65 driven by a reciprocator drive shaft reciprocates on guides 66 and supports a plurality of shorter straight nozzles 67 that are shown more clearly in FIG. 6. The nozzles 67 are hollow and straight and deposit individual yarn strands 68 received from spools 69 thereof on the upper yarn retaining portions 57 of the pins 53. It will be noted that the direction of travel of the upper portion of the chain 52 as seen in FIG. 4 is in the direction of the arrow C and thus the yarn strands 62 are wrapped around the lower yarn retaining portions 56 before the strands 68 are wrapped around the upper yarn retaining portions 57. Thus, the yarn strands 68 form a netting 42 like the netting 42 shown in FIG. 2 and therefore the composite netting on the pins 53 is a fine mesh netting similar to the netting 43 shown in FIG. 2. It will be noted that the difference between the apparatus shown in FIG. 2 and that shown in FIG. 4 is that adjacent pairs of pins in FIG. 2 are replaced by a single bent pin in FIG. 4.
The nettings 38, 42 are combined into a final netting in laminating pressure rollers 75 of a combining apparatus 76. A support supply roll 77 supplies a strip of support material 78 that is adhesive coated in a laminating adhesive coating apparatus 79. A second support supply roll 81 supplies a second strip of support material 82. The strips of support material 78 and 82 are laminated to the two nettings 38 and 42 in the laminating pressure rollers 75 and thus form a finished laminate strip 83 that is similar to the strip 21 shown in FIG. 1. (A single support sheet 78 could be used with the netting embedded in the adhesive.) A removal ramp 84 urges the laminate strip 83 up and off the upstanding pins 53 as the pins continue their forward motion as shown in FIG. 4. Guide rollers 85 direct the finished laminate 83 to a conventional packaging apparatus (not shown) for rolling and cutting and, if desired, for adhesive coating of one side of the finished laminate.
FIG. 7 shows a portion of a chain 91 supporting a plurality of upstanding pins 92 and a portion of an applicator shuttle 93 supporting a plurality of nozzles 94. FIG. 7 is drawn to the same scale as FIGS. 5 and 6 and shows the close spacing among the pins 92 and the nozzles 94 that is required by conventional apparatus to provide a netting as fine as the netting incorporated in the laminate 83. Bent pins 53 and nozzles 61 alleviate the close spacing problem inasmuch as each pin 53 efi'ectively replaces two conventional pins and, as will be seen by comparison of FIGS. 5, 6 and 7, permit wider spacing among the pins and the nozzles and thus faster operation.
Referring next to FIG. 8, there is shown the chain 52 supporting the upstanding pins 53 and a section of a first reciprocating applicator shuttle 58a that is similar to the shuttle 58 except that nozzles 61a supported thereby are straight and inclined rather than curved as are the nozzles 61. It will be appreciated from FIG. 8 that the same advantages described with respect to the curved nozzle configuration shown in FIG. 5 are realized with the embodiment depicted in FIG. 8. Preferably, the same second applicator shuttle apparatus 65 is used in conjunction with the shuttle applicator 58a.
Referring now to FIG. 9 there is shown a portion of a chain 101 similar to the endless chain belt 52 shown in FIG. 4 that supports a plurality of upstanding pins 102. The direction of travel of the chain 101 is in the direction of the arrow T shown in FIG. 9. FIG. 10 is a sectional view of the apparatus of FIG. 9 taken along the line 10l0 which shows that the upstanding pins 102 each comprise a lower yarn retaining portion 103 and an upper yarn retaining portion 104 that are vertically and horizontally separated, and that the pins 102 are bent in a direction transverse to the direction of travel of the chain 101, whereas the pins 53 shown in FIG. 5 were bent parallel to the direction of travel of the chain 52. A first netting shown by broken lines 105 is formed around the lower yarn retaining portions 103 and a second netting depicted by solid lines 106 is formed around the upper yarn retaining portions 104. It will be appreciated from an examination of FIG. 9 that the two nettings, when pressed together with combining apparatus similar to the combining apparatus 76 shown in FIG. 4 will yield a final fine mesh netting. Also, it will be appreciated that the yarn strands 105 and 106 can be looped around 2, 3 or more pins 102 as were the strands shown in FIG. 3. Shown in phantom in FIG. 10 are two inclined nozzles 107 and 108. The nozzle 107 is shown outside of the path of the pins 102 in the turnaround position and the nozzle 108 is shown shortly before passing between two upstanding pins 102. The nozzles 107 and 108 are shown to illustrate the spatial relationships between the nozzles and the upstanding pins 102. The yarn 106 is applied to the upper yarn retaining portion 104 with short straight nozzles similar to the nozzles 67 shown in FIG. 6. Thus, it will be apparent that upstanding pins 102 bent transversely to the direction of travel of the chain 101 can be utilized to provide the desirable superimposition effect and enable high speed production.
Referring next to FIG. 11 there is shown still another preferred upstanding pin. A chain 111 supports a plurality of pins 112, each pin comprising a first yarn retaining portion 113, a second yarn retaining portion 114 and a third yarn retaining portion 115. A reciprocating applicator shuttle 116 is schematically shown supporting a plurality of different nozzles that are utilized in conjunction with the pins 112. It should be understood that the difr'erent nozzles are shown on the shuttle 116 by way of illustration only and just one type of nozzle is used on any one shuttle. Utilization of the three tiered pins 112 requires a former with three shuttles but yields a finished netting that is a composite of three individual nettings and thus can be of a still finer mesh or the pins can be more widely spaced thus permitting faster production. The first two nozzles shown are a curved nozzle 117 and a straight, inclined nozzle 118, either of which is used to apply yarn to the first yarn retaining portion 113-. Shown next is a short curved nozzle 119 that is used to apply yarn to the second yarn retaining portion 114. It should be clear that a straight inclined nozzle similar to the nozzle 51a shown in FIG. 8 can be employed in place of the nozzle 119. Finally, a short straight nozzle 121 similar to the nozzle 67, shown in FIG. 6, is utilized to apply yarn tothe third yarn reraining portion Obviously, many modifications and variations of the present invention are possible in light of the above teachings. For example, the combining apparatus 76 can be replaced with a heat lamp to join the yarn strands at the intersections thereof to form a permanently bonded netting material such as onion bag material. It is to be understood, therefore, that the invention can be practiced otherwise than as specifically described.
What is claimed is:
1. Apparatus for forming nonwoven open-mesh netting comprising:
supply means for supplying a plurality of yarn strands;
forming means comprising two separated rows of spaced apart pins, each pin comprising a first yarn retaining portion and a second yarn retaining portion that is displaced in two directions from said first yarn retaining portion;
first applicator means for looping some of said yarn strands around said first yarn retaining portions;
second applicator means for looping other ones of said yarn strands around said second yarn retaining portions;
motive means for producing relative movement between said rows of pins and said applicator means whereby said first applicator means progressively.
loops some of said yarn strands around said first yarn retaining portions on different ones of said pins alternately located in each of said rows, so as to form a first netting, and said second applicator means progressively loops other ones of said yarn strands around said second yarn retaining portions on said different pins alternately located in each of said rows so as to form a second netting.
2. Apparatus according to claim 1 wherein said second yarn retaining portions are displaced from said first yarn retaining portions in a direction transverse to the direction of separation of said rows of pins.
3. Apparatus according to claim 2 wherein said first applicator means comprises first shuttle means including a plurality of first nozzles for releasing individual ones of some of said yarn strands and said second applicator means comprises second shuttle means including a plurality of second nozzles for releasing individual ones of said other ones of said yarn strands and said motive means comprises reciprocator means for reciprocating said first shuttle means and said second shuttle means in a direction substantially parallel to said direction of separation.
4. Apparatus according to claim 3 wherein said rows are parallel and said forming means comprises conveyor means for moving said pins in a direction of motion that is parallel to said rows.
'5. Apparatus according to claim 4 wherein said conveyor means comprises two endless belts to facilitate continuous motion of said conveyor means and one of said rows of pins is mounted on one of said endless belts and the other one of said rows of pins is mounted on the other one of said endless belts.
*6. Apparatus according to claim 5 wherein said parallel rows define a base plane and said yarn retaining portions are substantially perpendicular thereto.
7. Apparatus according to claim 5 wherein said parallel rows define a base plane and said second yarn retaining portions are displaced from said first yarn retaining portions in a direction perpendicular to said base plane.
8. Apparatus according to claim 6 wherein said second yarn retaining portions are displaced from said first yarn retaining portions in a direction parallel to said base plane.
9. Apparatus according to claim 7 wherein said second yarn retaining portions are parallel to said first yarn retaining portions.
10. Apparatus according to claim 9, wherein said pins.
are bent in said direction of travel so that said first netting is displaced from said second netting in said direction of travel.
11. Apparatus according to claim 10 wherein said first nozzles are bent in said direction of travel to facilitate passing of said first nozzles between said pins during reciprocation.
12. Apparatus according to claim 11. wherein each of said pins comprises a third yarn retaining portion that is displaced from said first yarn retaining portion and said second yarn retaining portion and said apparatus comprises third applicator means for looping yet other ones of said yarn strands around said third yarn retaining portions so as to form a third netting comprising a third shuttle means including a plurality of bent third nozzles for releasing individual ones of said yet other strands wherein said bent third nozzles are substantially parallel to said first nozzles.
13. Apparatus according to claim 9 wherein said pins are bent in said direction of separation so that said first netting is displaced from said second netting in said direction of separation.
14. Apparatus according to claim 13, wherein said first nozzles are bent in said direction of separation to bining means comprises laminating means comprising: support supply means for supplying a strip of support sheet with an adhesive coated surface; and
pressure means for pressing said final netting into said adhesive to form a laminate.
17. Apparatus according to claim 16 wherein said laminating means further comprises:
second support supply means for supplying a second strip of support sheet; and
laminating pressure means to form a laminate of said support sheet and said second support sheet with said final netting therebetween.
18. Apparatus according to claim 17 wherein said combining means comprises ramp means to remove said netting from said forming means.
19. Apparatus according to claim 16 wherein said laminating means comprises adhesive supply means for adhesive coating said surface of said support sheet.
'20. A method for making nonwoven open-mesh netting comprising the steps of:
providing two rows of spaced apart pins each pin having a first yarn retaining portion and a second yarn retaining portion displaced in two directions therefrom;
withdrawing a plurality of yarn strands from a source of supply;
progressively looping said plurality of yarn strands around said first yarn retaining portions on different ones of said pins alternately located in each of said rows to form a first netting;
withdrawing a second plurality of yarn strands from said source of supply; and I progressively looping said second plurality around said second yarn retaining portions on said different pins alternately located in each of said rows to form a second netting.
21. A method according to claim 20 comprising a laminating step for laminating said first netting and said second netting between two sheets of support material.
22. A method according to claim 20 comprising a combining step for combining said first netting and said second netting to form a final netting with smaller interstices than either said first netting or said second netting.
References Cited UNITED STATES PATENTS Estee et a1. 156-440 DANIEL J. FRITSCH, Primary Examiner U.S. Cl. X.R.
2i81 CL; 156-18 1, 439, 440, 441