Patent Publication Number: US-3874831-A

Title: Machine for producing pulp bats

Description:
United States Patent [19] Schroeder Apr. 1, 1975 [73] Assignee: Fibre Formations, lnc.,  
 Philadelphia, Pa.  
 [22] Filed: Aug. 9, i973 [2|] Appl. No.: 387,143  
 [75] Inventor:  
 [52] US. Cl 425/80, 425/223, 425/83. 425/DlG. 200. 264/l09 I51] Int. Cl. B29c 13/04, B29c 15/00 I58] Field of Search 425/83, 81, 223, 80, 224. 425/504, 505, DIG. 200; 264/l09 [56] References Cited UNITED STATES PATENTS 2,810,426 lU/l957 Till ct al. 425/83 X 3,088,859 5/l963 Smith 425/83 X 3,l45,430 8/l964 Caron A 425/83 X 3.20l.499 8/1965 Cusse 425/81 X 3,558,380 l/l97l Pook 425/505 X 3,644,078 2/l972 Tachibana ct ul. 425/83 3,652,353 3/1972 Bclisle ct ul. 425/83 X 3.792.943 2/l974 Hclgcsson 425/83 Primary Iz&#39;xuminer-Robert L, Spicer. Jr Almrney. Agem, or Firm-Smith, Harding, Earley &amp; Follmer [57] ABSTRACT A machine for producing pulp bats has a rotary shredder, a vacuum drum with small openings in its periphcry and duct means to convey shredded pulp from the shredder to the vacuum drum. An inner drum cuts off the openings from the vacuum to release material from the drum. Advantageously air jet means assist in releasing material from the drum. In one embodiment, guide means are adapted to guide a porous sheet to pass over a portion of the drum for the accumulation of shredded pulp on the porous sheet and then from a terminal position away from the drum. Means guide a second sheet adjacent the said terminal position to re tain the accumulated shredded pulp between the porous sheet and the said second sheet, In a second embodiment, the shredded pulp accumulates directly on the drum and means guide a pair of opposed sheets adjacent the point of release of the shredded pulp from the drum to entrain the accumulated shredded pulp and carry it away from the drum.  
 [2 Claims, 15 Drawing Figures PATENTEU APR 1 YS SHEET 5 OF 6 FIG. 8.  
 FIG. IO.  
 PATENTED APR 1 I975 3m 6 [If g FIG. l3.  
 FIG. 14.  
 MACHINE FOR PRODUCING PULP BATS BRIEF SUMMARY OF THE INVENTION It is well known in the prior art to take shredded pulp and form a hat by forming a sandwich of the shredded pulp between a pair of opposed webs or sheets. U.S. Pat. No. 3.1 83.l4l dated May ll. I965 (Holden et al. which is incorporated herein by reference. is typical and discloses entraining shredded pulp in a stream of air and depositing it between a pair of opposed webs. While the machine of this patent is satisfactory for many purposes. it fails to provide for the degree of uniformity of the shredded pulp between the webs throughout as is desired for some applications. In addi tion. for high speed operation it is necessary that both webs in the said patent be of porous material for satisfactory results. In accordance with the present invention. a highly uniform layer of shredded pulp of improved quality is achieved and high speed operation is possible even when one of the webs is not porous. The latter aspect is important since the pulp bats are in wide usage as underpads for patients beds and normally require that one side of the but he nonporous.  
 BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a schematic view of apparatus for forming pulp bats;  
  FIG. 2 is a side elevation partially broken away of apparatus in accordance with the invention. partially broken away;  
  FIG. 2A is a view taken on the plane indicated by the line 2A2A in FIG. 2;  
  FIG. 3 is a rear elevation. partially broken away. of the vacuum drum system of FIG. 2;  
  FIG. 4 is a rear elevation. partially broken away. of the drum of FIG. 3 with a screen added;  
  FIG. 5 is a front elevation (taken on the plane indicated by the line 5-5 in FIG. 6) of the drum of FIG. 3. partially broken away;  
  FIG. 6 is a vertical section taken on the plane indicated by the line 6-6 in FIG. 5&#39;.  
  FIG. 7 is a vertical section through a portion of the air conduit in the drum system;  
  FIG. 8 is a view taken on the plane indicated at 8-8 in FIG. 7:  
  FIG. 9 is a bottom plan view of the inner drums of the apparatus of FIG. 2;  
  FIG. 10 is a plan view of a but made using the apparatus of FIG. 1;  
  FIG. II is a view taken on the plane indicated by the line ll-II in FIG. I0;  
  FIG. I2 is a view taken on the plane indicated by the line I2I2 in FIG. I0;  
  FIG. I3 is a view illustrating the operation of the apparatus of FIG. 2. and  
  FIG. I4 is a view illustrating the operation of an alternative embodimcnt of the invention.  
 DETAILED DESCRIPTION Referring first to FIG. I. a machine 2 for producing pulp bats has a pulp sheet feeding device 4 which as best seen in FIG. 2 has opposed gears 6 and 8 and opposed gears I0 and I2 which engage a sheet 14 of pulp and advance it into a shredder I6 which is conventional fully disclosed in detail in U.S. Pat. No. 3.l83.l4l and hence need not be described in detail here. As best seen in FIG. 2 the pulp 14 is shredded by a plurality of circular saw blades. one of which is shown at I8 and the shredded pulp 20 is discharged into a conduit 2|. Coir duit 2l has a hinged baffle 21A which extends the full width of conduit 2] and is fixed in the desired position by a bolt 218 secured to the baffle. passing through arcuatc opening 21C in the side wall 21B of shredder I6 and secured by wing nut 2IF.. Static bars 22 are positioned adjacent opening 23 where air enters the conduit 21 and static bars 24 are positioned in housing 26 which has an air intake opening 28 and which is on the top of opening 27 in conduit 2| (FIG. 2A l. Opening 27 is controlled by five slidably adjustable air baffles 29 (FIG. 2A). Each baffle has a slot 30 engaged by a headed screw 30A threaded into conduit 2] to provide for its adjustment. The static bars function in a well known manner to neutralile any changes on the shredded pulp by ioni/ing the air to cause positively charged material to be neutraliyed by attracting free negative ions and negatively charged material to he neutralized by attracting free positive ions. In the instant case the pulp tends to be randomly charged with either polarity.  
  Conduit 21 extends downwardly to terminate imme diately adjacent a vacuum drum system 32. As seen in FIGS. 2 and 3 drum system 32 has a rotating drum 34 which is mounted for rotation on a plurality of rollers 36 which are rotatably mounted on brackets 38. As best seen in FIG. 3. drum 34 has a central portion 44 with uniformly spaced small openings (perforations) 46. Outboard of central portion 44 are mounted rings 48 and 50 respectively. each of which is respectively adjacent a set of rollers 36 to keep the drum centered.  
 An additional ring 52 is secured to the left hand end of drum 34 as viewed in FIG. 3 and has in turn secured thereto a sprocket 54.  
  A fixed inner suction drum 62 is mounted within drum 34. As best seen in FIG. 5. drum 62 has an opening 64 which is surrounded by sealing strips 66. 68, 7&#34; and 72 which may be of. for example. felt. plastic. or wood. These scaling strips together with an additional longitudinal strip 74 secured to drum 62 (FIG. 3). which may he of the same material. act to center drum 62 within drum 34. Drum 62 has an end wall 78 to which is secured as by welding a shaft 80 which is mounted in an opening 82 in a standard 84. A set screw 86 engages shaft 80 to prevent its rotation and to permit adjustment of the angular position of drum 62 with respect to drum 34 (FIG. 3).  
  As seen in FIGS. 5-9. an angle member 90 is secured to the interior of drum 62 by machine screws 92 over openings 94 in drum 62. Angle member 90 has one end closed off by end wall 78 of drum 62 and the other end closed off by a plate 96 (FIG. 9). An air supply pipe 98 passes through wall 78 to supply air to the space cncompasscd by the angle member 90 and drum 62.  
  The open end I02 of vacuum drum 62 is connected to a conduit 104 (FIG. 5) which as shown schematically in FIG. 2. is connected to an exhaust blower I06.  
  As best seen in FIG. 2. drum 34 is rotated by means of a chain 108 connected to sprocket 54 and to sprocket IIO which is driven by a gear reducer II2.  
  A porous fabric web passes through a small opening 122 into the interior of conduit 2t and about the central portion 44 of drum 34 and overlying openings 46. and thence away from drum 34 to drive rollers I24 and 126 (FIG. I). As best seen in FIGS. 2 and 3. a guide roller 130 is provided to guide a nonporous web 132 (FIG. 1) adjacent drum 34.  
  Since the au\ilary apparatus necessary to make the bat is well known to the art. it will be described in con neetion with the operation of the foregoing described apparatus which follows. Shredded pulp 20 formed by applying pulp sheets I4 to shredder I6 is entrained in conduit 2| and conveyed in the direction of drum 34 by the action of blower I06 pulling air through openings 46 in rotating drum 34. opening 64 in suction drum 62 and through conduit I04. Since sheet I20 overlies drum 34. the air is pulled through this sheet and causes the shredded pulp 20 to form a bed I36 of shredded pulp (FIG. I3). The llow of air through conduit 2] tends to be non-uniform in nature. Thus at the outset it is necessary in order to get pulp bed uniform to adjust air baffles 29 until the flow of air through conduit 2I is substantially uniform. Sheet I20 and the uniform bed of shredded pulp I36 are rotated together with drum 34 out of the confines of conduit 2I to a position adja cent roller I30 and nonporous sheet 132 at which point they are beyond opening 64 in drum 62 and are being pulled off drum 34 by rollers I24 and I26 (FIG. I). Advantageously jets of air are introduced from the space enclosed by angle member 90 through openings 94 in drum 62 to aid the sheet I20 and the associated bed I36 ol&#39;shredded pulp to freely disengage from drum 34 and come into contact with sheet 32.  
  Prior to arriving at guide roller I30. web I32 has passed around a guide roller I40 (FIG. I) and had an adhesive applied to its surface by a roller I42 which received the adhesive from a roller I44 which in turn received it from a roller I46 mounted in an adhesive con tainer I48.  
  As shown schematically in FIG. I. after leaving guide roller I30 the assembly of webs I20 and I32 with uniform bed I36 of shredded pulp passes through drive rollers I24 and I26 and thence to a transverse gluing station I52 where at spaced intervals the combination is engaged by gluing head I54. which has been supplied with an adhesive by adhesive supply roller I56. while the combination is backed up by backing roller I58 to provide adherence between webs I20 and I32 in the area where the webs are later severed to form separate bats. The assembly then passes to an embossing station indicated at I62 which embosses the assembly where it has just been transversely glued and then to a folding station I64 where the outer edges of web I32. which is somewhat wider than web I20, are folded over web I20 and adhered thereto by the previously applied adhesive. The assembly then precedes to cutting station I66 where the webs are severed in the embossed area to form separate bats to complete the operation. All of the operations following rollers I24 and I26 are well known to the art.  
  A completed but I70 is shown in FIGS. II2. The edges 172 of web I32 are turned up over web I and adhered thereto by adhesive indicated at I74 (FIG. II I. Each end I76 is embossed as indicated at I78 and adhered together by an adhesive I80 which permeates the embossed portion of web I20 and bed I36 of shredded pulp and contacts web I32 (FIG. 13).  
 ALTERNATIVE EMBODIMENT Alternatively the uniform shredded pulp bed may be formed directly on the drum. As shown in FIG. 4. a cy lindrical screen I84 of sufficient fineness to prevent the passage therethrough of the shredded pulp (for example. from about 710 to about I05 mesh) overlies the (III central portion 44 of drum 34. The screen 184 is secured in place by virtue of its elasticity. In this alternative embodiment there is one additional minor modification of the originally described embodiment. Absorbent web I is guided about a guide roller I92 rather than passing around drum 34. Otherwise. this alterna tive embodiment is the same as the embodiment described above.  
  In operation of the alternative embodiment. the shredded pulp 20 accumulates evenly on screen I84 and is carried thereon beyond opening 64 in fixed drum 62 to a point opposite the space enclosed by angle member 90 where jets of air pass through openings 94 in drum 62 and thence through openings 46 in drum 34 to force the bed of shredded pulp off screen I84 and onto the nonporous web I32 on which it is carried to the left as viewed in FIG. I4 to be joined by absorbent web I90 which passes around guide roller I92 and overlies the pulp bed.  
  Typically. web may be a fabric web of. for example. woven or unwoven cotton. woolen. nylon. rayon or linen fabric or paper which will permit the passage of air. The nonporous web I32 may be. for example. polyethylene. Absorbent web I90 may be. for example. cotten. wool or paper and need not permit the passage of air.  
  The above described embodiments are illustrative and are not intended to be limiting.  
 I claim:  
  I. A machine for producing uniform pulp bats comprising:  
 a rotary shredder.  
 a drum having perforations in its periphery. means to guide a porous sheet to pass over a portion of the drum and then away from the drum at a terminal position.  
 duct means to convey shredded pulp from the shredder to said porous sheet for a uniform accumulation on said porous sheet.  
 vacuum means communicating with the inner periphery ofthe drum opposite the duct means and terminating adjacent the said terminal position. and  
 means to guide a second sheet adjacent to and then away from said terminal position to retain the accumulated shredded pulp between the porous sheet and said second sheet.  
  2. A machine in accordance with claim I having means adjacent said duct means to neutralize any electrical charges on the shredded pulp.  
  3. A machine in accordance with claim I in which the vacuum means includes a fixed inner drum having an opening opposite the duct means.  
  4. A machine in accordance with claim I having means to deliver air under pressure to the inner periphery of the drum opposite the perforations to provide jets of air from said perforations adjacent the said terminal position.  
  5. A machine in accordance with claim I having means to control the flow of air through the duct means to provide a uniform flow of air through the duct means.  
 6. A machine for producing pulp bats comprising:  
 a rotary shredder.  
 a vacuum drum having perforations in its periphery.  
 a screen covering the drum having a mesh opening that is smaller than the particles of shredded pulp.  
 duct means to convey shredded pulp from the shredder to the screen covered vacuum drum for accumulation on the periphery of the screen. vacuum means communicating with the inner periphcry of the drum opposite the duct means. and  
 means to guide a pair of opposed sheets adjacent to said screen covered vacuum drum to entrain the accumulated shredded pulp as it is released from the drum at a terminal position and carry it away from the drum,  
 said vacuum means terminating adjacent said terminal position to release the accumulated shredded pulp.  
  7. A machine in accordance with claim 6 having means adjacent said duct means to neutralize any electrical charges on the shredded pulp.  
 8. A machine in accordance with claim 6 in which the vacuum means includes a fixed inner drum having an Ill (all  
 opening opposite the duct means.  
  9. A machine in accordance with claim 6 having means to deliver air under pressure to the inner periphery ol&#39; the drum opposite the perforations to provide jets of air from said perforations through the screen adjacent the said terminal position.  
  It). A machine in accordance with claim 6 having means to control the How of air through the duct means to provide a uniform flow of air through the duct means.  
  II. A machine in accordance with claim 3 having means for rotatahly adjusting the inner drum to vary the angular position of the opening.  
  [2. A machine in accordance with claim 8 having means for rotatahl adjusting the inner drum to vary the angular position of the opening.