US2411416A - Papermaking apparatus - Google Patents

Papermaking apparatus Download PDF

Info

Publication number
US2411416A
US2411416A US505169A US50516943A US2411416A US 2411416 A US2411416 A US 2411416A US 505169 A US505169 A US 505169A US 50516943 A US50516943 A US 50516943A US 2411416 A US2411416 A US 2411416A
Authority
US
United States
Prior art keywords
felt
roll
box
paper
arms
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US505169A
Inventor
Frederick A Dieckbrader
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hinde & Dauch Paper Co
Original Assignee
Hinde & Dauch Paper Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hinde & Dauch Paper Co filed Critical Hinde & Dauch Paper Co
Priority to US505169A priority Critical patent/US2411416A/en
Application granted granted Critical
Publication of US2411416A publication Critical patent/US2411416A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • DTEXTILES; PAPER
    • D21PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21HPULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H23/00Processes or apparatus for adding material to the pulp or to the paper
    • D21H23/02Processes or apparatus for adding material to the pulp or to the paper characterised by the manner in which substances are added
    • D21H23/22Addition to the formed paper
    • D21H23/24Addition to the formed paper during paper manufacture
    • D21H23/26Addition to the formed paper during paper manufacture by selecting point of addition or moisture content of the paper

Definitions

  • the present invention relates to paper-making apparatus and more particularly to a device for continuously applying a layer of filling material, such as asphalt, starch, formaldehyde, etc. between layers of paper stock on the felt during the passage of the felt over the'cylinders at the wet end of a cylinder paper-making machine for waterproofing, stifiening, preserving or otherwise aflecting the properties of the paperboard.
  • a layer of filling material such as asphalt, starch, formaldehyde, etc.
  • One of the main objects of the present. invention is to provide a means for applying a uniform coating of filling material to the wet Paper stock adhering to the felt without injury to the paper sheet.
  • a more specific object of the present invention is to provide means for firmly holding the paper stock to the felt during the application of the layer of filling material thereto.
  • a further object of the present invention is to provide a coating mechanism that is adapted to be mounted between successive cylinder'molds in a conventional paper-making machine.
  • Figure 1 is a side elevation of a portion of a paper-making machine showing the device of the present invention applied thereto;
  • Fig. 2 is a section taken on the line indicated at 22 in Fig. l;
  • Fig. 3 is a fragmentary vertical section on an enlarged scale, taken on the line indicated at 3-4 in Fig. 2.
  • Fig. 4 is a section taken on the line indicated at 4-4 in Fig. 3.
  • the device of the present invention is shown mounted upon one of the vats I at the wet end of a cylinder paper-making machine.
  • a cylinder mold 2 that collects a layer of paper-forming fibers from the liquid in the vats on its periphery and transfers this layer of fibers to a felt I that travels continuously paper stock on the cylinder mold and the underside of the felt or between the paper stock on the cylinder and a layer of paper stock adhering to the underside of the felt.
  • Each couch roll 4 is carried by arms 5 that are pivotally attached to columns 6 mounted upon opposite sides of the vat I and adjacent the cylinder mold in the vat.
  • the device of the present invention may be applied to the wet and of a cylinder paper machine to apply a coating to paper stock adhering to the underside of the felt after one or more layers of paper stock have been picked up by the felt.
  • the two vats herein shown may be any two of the vats of the paper-making machine and it is to be understood that identical coating devices may be mounted between other cylinder molds in the machine where additional layers of the filling material in the paperboard are desired.
  • an applicator box I In the top portion of one of the vats adjacent the cylinder mold therein, there is mounted an applicator box I that extends across the space between the side walls of the vat with its open top above the top of the vat.
  • the box 7 conains the filling material to be applied to the paper stock which may be in solution or in suspension in a liquid, and means is provided for continuously circulating the liquid through the box I.
  • a circulating tank 8 At one side of the vat there is mounted a circulating tank 8 and a pump 9 that draws liquid from the lower portion of the tank 8 and discharges it through a pipe l0 into one end of the box I.
  • a drain pipe H From the other end of the box I a drain pipe H leads into the upper portion of the circulating tank 8.
  • a suitable batch tank I 2 may be provided in which the solution, emulsion or suspension of the filling material may be formed and from which it may be delivered into the circulatin tank 8.
  • an applicator roll l3 preferably knurled, which projects slightly above the top box I and which dips into the liquid contained in the box so that a continuous film of filling material will be maintained upon the roll l3 when it is rotated.
  • the roll i3 is mounted upon a shaft I 4 journaled in the ends of the box I and preferably extends the full width of the felt 3 to apply a coating throughout the width of the paper sheet.
  • brackets l5 are attached to the columns 6 at opposite sides of the vat upon which the box I is mounted. These brackets serve to support two L-shaped suspension memand an arm l9 that is disposed substantially parallel with the felt 3, the arms l8 and IQ of each member extending from the pivot I! that is located near the'angle between the two arms. Adjacent their free ends, the arms l9 have bearing brackets depending therefrom and in the brackets 20 there is journalled a shaft 2
  • a suction box 24 Mounted on the arm l9-between the pressure roller 22 and the pivot I! there is a suction box 24 that has bolts 25 fixed to the top wall thereof and extending upwardly through elongated, longitudinal slots 26 in the arms l9. Each of thebolts 25 has two nuts 21 and 28 thereon that engage the top and bottom faces of the arms IS.
  • the suction box 24 has a bottom face 29 preferably formed of wood and provided with a longitudinal slot 30 extending the full length of the roller l3.
  • One end of the suction box may be connected by a flexible conduit 3
  • the suction box 24 bears upon the upper surface of the film 3 above the roller l3, the box being preferably positioned so as to lightly press the felt 3 against the periphery of the applicator roll l3.
  • the slot 30 is located directly over the engaging portion of the applicator roll l3 so that the suction within the box serves to draw the portion of the paper sheet passing between the suction box and the roll l3 tightly against the underside of the film 3, so that engagement of the paper sheet.
  • of the pressure roll 22 has a pulley 32 fixed thereto, which receives a crossed belt 33 that extends over a pulley 34 fixed to the shaft l4 of the applicator roll.
  • the roll 22 is driven without slippage by the traveling felt 3 and drives the roll l3 through the belt 33 at the proper speed to maintain a non-slip rolling engagement with the underside of the paper sheet carried by the felt.
  • the roll 22 and the pulley 32 are of the same diameters as the roll l3' and pulley 34 so that the peripheral speed of both rolls is the same as the linear speed of the felt.
  • the suspension members I 6 are adapted to'be adjusted about the axis of the pivot H to vary the pressure of the suction box 24 and roll 22 on the felt 3 by means of screws 35 pivoted to the columns and extending through openings in the arms I8 and handwheels 36 that have threaded engagement with the screws 35 and bear against the arms l8.
  • the felt 3 may be held with the proper pressure against the applicator roll I3.
  • brackets 20 are preferably adjustably connected to the arms l9 by means of bolts 31 passing through the brackets 20 and through longitudinal slots 38 in the arms 19. By adjusting the brackets 20 on the arms IS the proper tension may be applied to the belt 33.
  • the top of the applicator roll I3 is below the normal path of travel of the felt 3 and, when the applicator is not in use, the supporting members l6 are actuated to hold the roll 22 and suction box 24 clear of the felt 3 so that the normal 0peration of the machine is not interfered with.
  • a batch of the material to be applied is made up in the batch tank I 2, run into the circulating tank 8 and then circulated through the applicator 'box I by means of the circulating pump 9.
  • the felt roll 22 and suction box 24 are lowered upon the felt 3 until the felt is depressed firmly against the applicator roll by the leading edge of the bottom face 29 of the suction box.
  • the helper drive belt 33 is then put in place.
  • the material prepared for application in the batch tank l2 and circulated through the applicator box 1 by means of the circulating pump 9 is picked up by the knurled applicator roll l3 and applied to the sheet of paper that is adhering to the underside of the felt 3.
  • the following cylinders 2 each add their layer of paper stock and the completed board then consists of top and bottom layers composed of conventional paper stock with an intermediate layer of the filling material.
  • the device of the present invention continuously applies an unbroken film ,of the filling material to the wet and fragile sheet of paper stock on the felt, damage to the paper being avoided by holding the paper sheet to the felt by suction and a uniform, unbroken coating being insured by the action of the knurled applicator roll over which the felt 3 travels without slippage due to the helper drive.
  • a device for applying filling material to paper stock carried by the felt comprising a box within one of the vats alongside its cylinder, an applicator roll mounted in the box with its top edge above the top thereof, means for maintaining a supply of liquid filling material in said box covering the lower portion of said roll, a suction box overlying the rol1 and engaging the felt above said roll for pressing the felt against the roll and maintaining a suction upon the paper stock passing over said roll, and means for adjusting said box to regulate the pressure of the felt against said roll.
  • a device for applying filling material to paper stock carried by the felt comprising a box within one of the vats alongside its cylinder, an applicator roll mounted in the box with its top edge above the top thereof, means for maintaining a supply of liquid filling material in said box covering the lower portion of said roll, a suction box overlying the roll and engaging the felt above said roll for pressing the felt against the roll and maintaining a suction upon the paper stock passing over said roll, a pressure roll engaging the top of the felt adjacent said suction box, means for simultaneously adjusting said pressure roll and suction box to regulate the pressure of the felt against said applicator roll, and a crossed belt forming a driving connection between said pressure roll and applicator roll.

Landscapes

  • Paper (AREA)

Description

1946- F. A. DIECKBRADER' PAPERMAKING APPARATUS Filed 001;. 6, 1943 2 Sheets-Sheet 1 Frederick A.Dieckbrader 1'- 71x47, ATTORNEYS Nov. 19, 1946. F. A. DIECKBRADER PAPERMAKING APPARATUS Filed Oct. 6, 1943 2 Sheets-Sheet 2 I I I Ill llllllll'bllllllllll l'l llllllll ll l ilalaallJ v l l O 4 I|||||||L INVENTOR r h o S .w J A m k a wv m F Patented Nov. 19, 1946 14 a PAPERMAKING arraiia'rus Frederick A. Dieckbrader, Toronto, Ontario, Canada, assignor to The Hinde & Danch Paper Company, Sandusky, Ohio, a corporation of Ohi Application October 6, 1943, Serial No. 505,169
4 Claims. 1
The present invention relates to paper-making apparatus and more particularly to a device for continuously applying a layer of filling material, such as asphalt, starch, formaldehyde, etc. between layers of paper stock on the felt during the passage of the felt over the'cylinders at the wet end of a cylinder paper-making machine for waterproofing, stifiening, preserving or otherwise aflecting the properties of the paperboard.
One of the main objects of the present. invention is to provide a means for applying a uniform coating of filling material to the wet Paper stock adhering to the felt without injury to the paper sheet.
A more specific object of the present invention is to provide means for firmly holding the paper stock to the felt during the application of the layer of filling material thereto.
It is also an object of the invention to provide an applicator roll that bears lightly but without slippage against the paper stock carried by the felt.
A further object of the present invention is to provide a coating mechanism that is adapted to be mounted between successive cylinder'molds in a conventional paper-making machine.
With the above and other objects in view, the invention may be said to comprise the apparatus as illustrated in the accompanying drawings, hereinafter described and particularly set forth in the appended claims, together with such variations and modifications thereof as will be apparent to one skilled in the art to which the invention pertains.
Reference should be had to the accompanying drawings forming a part of this specification, in which:
Figure 1 is a side elevation of a portion of a paper-making machine showing the device of the present invention applied thereto;
Fig. 2 is a section taken on the line indicated at 22 in Fig. l; and
Fig. 3 is a fragmentary vertical section on an enlarged scale, taken on the line indicated at 3-4 in Fig. 2.
Fig. 4 is a section taken on the line indicated at 4-4 in Fig. 3.
In the accompanying drawings, the device of the present invention is shown mounted upon one of the vats I at the wet end of a cylinder paper-making machine. In each of the vats i there is mounted a cylinder mold 2 that collects a layer of paper-forming fibers from the liquid in the vats on its periphery and transfers this layer of fibers to a felt I that travels continuously paper stock on the cylinder mold and the underside of the felt or between the paper stock on the cylinder and a layer of paper stock adhering to the underside of the felt. Each couch roll 4 is carried by arms 5 that are pivotally attached to columns 6 mounted upon opposite sides of the vat I and adjacent the cylinder mold in the vat.
The device of the present invention may be applied to the wet and of a cylinder paper machine to apply a coating to paper stock adhering to the underside of the felt after one or more layers of paper stock have been picked up by the felt. The two vats herein shown may be any two of the vats of the paper-making machine and it is to be understood that identical coating devices may be mounted between other cylinder molds in the machine where additional layers of the filling material in the paperboard are desired. In the top portion of one of the vats adjacent the cylinder mold therein, there is mounted an applicator box I that extends across the space between the side walls of the vat with its open top above the top of the vat. The box 7 conains the filling material to be applied to the paper stock which may be in solution or in suspension in a liquid, and means is provided for continuously circulating the liquid through the box I. At one side of the vat there is mounted a circulating tank 8 and a pump 9 that draws liquid from the lower portion of the tank 8 and discharges it through a pipe l0 into one end of the box I. From the other end of the box I a drain pipe H leads into the upper portion of the circulating tank 8. A suitable batch tank I 2 may be provided in which the solution, emulsion or suspension of the filling material may be formed and from which it may be delivered into the circulatin tank 8. Withinthe box I there is mounted an applicator roll l3, preferably knurled, which projects slightly above the top box I and which dips into the liquid contained in the box so that a continuous film of filling material will be maintained upon the roll l3 when it is rotated. The roll i3 is mounted upon a shaft I 4 journaled in the ends of the box I and preferably extends the full width of the felt 3 to apply a coating throughout the width of the paper sheet.
Above the felt 3 brackets l5 are attached to the columns 6 at opposite sides of the vat upon which the box I is mounted. These brackets serve to support two L-shaped suspension memand an arm l9 that is disposed substantially parallel with the felt 3, the arms l8 and IQ of each member extending from the pivot I! that is located near the'angle between the two arms. Adjacent their free ends, the arms l9 have bearing brackets depending therefrom and in the brackets 20 there is journalled a shaft 2| that carries a pressure roller '22 that preferably extends the full width of the felt 3. The pressure roller 22 bears against the top face of the felt 3 during operation and has its cylindrical periphery covered with a layer 23 of felt that serves to resist slipping between the roller 22 and the felt 3. I
Mounted on the arm l9-between the pressure roller 22 and the pivot I! there is a suction box 24 that has bolts 25 fixed to the top wall thereof and extending upwardly through elongated, longitudinal slots 26 in the arms l9. Each of thebolts 25 has two nuts 21 and 28 thereon that engage the top and bottom faces of the arms IS. The suction box 24 has a bottom face 29 preferably formed of wood and provided with a longitudinal slot 30 extending the full length of the roller l3. One end of the suction box may be connected by a flexible conduit 3| to a suction pump (not shown) for maintaining a sub-atmospheric pressure within the box.
Duringoperation of the machine, the suction box 24 bears upon the upper surface of the film 3 above the roller l3, the box being preferably positioned so as to lightly press the felt 3 against the periphery of the applicator roll l3. The slot 30 is located directly over the engaging portion of the applicator roll l3 so that the suction within the box serves to draw the portion of the paper sheet passing between the suction box and the roll l3 tightly against the underside of the film 3, so that engagement of the paper sheet.
with the roll l3 will not cause the paper sheet to be loosened from the felt.
To enable an unbroken liquid film to be continuously transferred from the surface of the applicator roll to the paper sheet on the underside of the felt, it is desirable that the roll l3 engage the paper sheet on the felt without slippage and,
since the applicator roll l3 bears lightly against the paper stock, it is desirable that means be provided to drive the roll l3 at a peripheral speed that corresponds to the linear speed of the felt. To this end, the shaft 2| of the pressure roll 22 has a pulley 32 fixed thereto, which receives a crossed belt 33 that extends over a pulley 34 fixed to the shaft l4 of the applicator roll. The roll 22 is driven without slippage by the traveling felt 3 and drives the roll l3 through the belt 33 at the proper speed to maintain a non-slip rolling engagement with the underside of the paper sheet carried by the felt. As herein shown, the roll 22 and the pulley 32 are of the same diameters as the roll l3' and pulley 34 so that the peripheral speed of both rolls is the same as the linear speed of the felt.
The suspension members I 6 are adapted to'be adjusted about the axis of the pivot H to vary the pressure of the suction box 24 and roll 22 on the felt 3 by means of screws 35 pivoted to the columns and extending through openings in the arms I8 and handwheels 36 that have threaded engagement with the screws 35 and bear against the arms l8. By properly adjusting the suction box 24 and the roll 22 by means of the handwheels 36, the felt 3 may be held with the proper pressure against the applicator roll I3. brackets 20 are preferably adjustably connected to the arms l9 by means of bolts 31 passing through the brackets 20 and through longitudinal slots 38 in the arms 19. By adjusting the brackets 20 on the arms IS the proper tension may be applied to the belt 33.
The top of the applicator roll I3 is below the normal path of travel of the felt 3 and, when the applicator is not in use, the supporting members l6 are actuated to hold the roll 22 and suction box 24 clear of the felt 3 so that the normal 0peration of the machine is not interfered with.
' To put the device of the present invention into operation, a batch of the material to be applied is made up in the batch tank I 2, run into the circulating tank 8 and then circulated through the applicator 'box I by means of the circulating pump 9. The felt roll 22 and suction box 24 are lowered upon the felt 3 until the felt is depressed firmly against the applicator roll by the leading edge of the bottom face 29 of the suction box. The helper drive belt 33 is then put in place. After the applicator has been operatively connected as above described, the material prepared for application in the batch tank l2 and circulated through the applicator box 1 by means of the circulating pump 9 is picked up by the knurled applicator roll l3 and applied to the sheet of paper that is adhering to the underside of the felt 3. The following cylinders 2 each add their layer of paper stock and the completed board then consists of top and bottom layers composed of conventional paper stock with an intermediate layer of the filling material.
The device of the present invention continuously applies an unbroken film ,of the filling material to the wet and fragile sheet of paper stock on the felt, damage to the paper being avoided by holding the paper sheet to the felt by suction and a uniform, unbroken coating being insured by the action of the knurled applicator roll over which the felt 3 travels without slippage due to the helper drive.
It is to be understood that variations and modifications of the specific device herein shown felt, means for maintaining a coating of filling material upon the surface of said roll, a suction box overlyingthe roll and extending transversely across the felt and engaging the top of the felt above said roll adjacent the point of engagement of the felt with said roll for maintaining a suction upon paper stock engaging said roll, a pressure roll parallel with the suction box and in engagement with the top of the felt adjacent the box, and means for simultaneously raising or lowering said pressure roll and suction box.
2. A device for continuously applying a layer of filling material to paper stock adhering to the underside of the felt during its trave1 between felt, means for maintaining a coating of filling material upon the surface of said roll, a pair of The.
parallel arms mounted above the felt, one at each side of the felt and extending longitudinally thereof, means for supporting said arms to swing about a horizontal axis adjacent an end thereof, a pressure roll rotatably supported upon said arms adjacent their free ends, a suction box attached to said arms between the roller and the pivotal axis, and means for adjusting said arms about said pivotal axis to regulate the pressure of the roll and box upon the felt.
3. The combination with a wet end of a cylinder paper machine having vats positioned side by side, mold cylinders in each vat and a felt traveling over the cylinders to pick up layers of paper stock therefrom, of a device for applying filling material to paper stock carried by the felt, comprising a box within one of the vats alongside its cylinder, an applicator roll mounted in the box with its top edge above the top thereof, means for maintaining a supply of liquid filling material in said box covering the lower portion of said roll, a suction box overlying the rol1 and engaging the felt above said roll for pressing the felt against the roll and maintaining a suction upon the paper stock passing over said roll, and means for adjusting said box to regulate the pressure of the felt against said roll.
4. The combination with the wet end of a cylinder paper machine having vats positioned side by side, mold cylinders in each vat and a felt traveling over the cylinders to pick up layers of paper stock therefrom, of a device for applying filling material to paper stock carried by the felt, comprising a box within one of the vats alongside its cylinder, an applicator roll mounted in the box with its top edge above the top thereof, means for maintaining a supply of liquid filling material in said box covering the lower portion of said roll, a suction box overlying the roll and engaging the felt above said roll for pressing the felt against the roll and maintaining a suction upon the paper stock passing over said roll, a pressure roll engaging the top of the felt adjacent said suction box, means for simultaneously adjusting said pressure roll and suction box to regulate the pressure of the felt against said applicator roll, and a crossed belt forming a driving connection between said pressure roll and applicator roll.
'FREDERICK A. DIECKBRADER.
US505169A 1943-10-06 1943-10-06 Papermaking apparatus Expired - Lifetime US2411416A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US505169A US2411416A (en) 1943-10-06 1943-10-06 Papermaking apparatus

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US505169A US2411416A (en) 1943-10-06 1943-10-06 Papermaking apparatus

Publications (1)

Publication Number Publication Date
US2411416A true US2411416A (en) 1946-11-19

Family

ID=24009308

Family Applications (1)

Application Number Title Priority Date Filing Date
US505169A Expired - Lifetime US2411416A (en) 1943-10-06 1943-10-06 Papermaking apparatus

Country Status (1)

Country Link
US (1) US2411416A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2500923A (en) * 1946-06-06 1950-03-21 American Asbestos Ind Inc Apparatus for manufacturing cement-asbestos board
US2503466A (en) * 1947-10-21 1950-04-11 American Asbestos Ind Inc Apparatus for manufacturing cement-asbestos board
US2650524A (en) * 1946-06-06 1953-09-01 American Asbestos Ind Inc Apparatus for manufacturing cement-asbestos board
US2694963A (en) * 1949-04-08 1954-11-23 Patent & Licensing Corp Apparatus for the manufacture of waterproofed multiply sheets

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2500923A (en) * 1946-06-06 1950-03-21 American Asbestos Ind Inc Apparatus for manufacturing cement-asbestos board
US2650524A (en) * 1946-06-06 1953-09-01 American Asbestos Ind Inc Apparatus for manufacturing cement-asbestos board
US2503466A (en) * 1947-10-21 1950-04-11 American Asbestos Ind Inc Apparatus for manufacturing cement-asbestos board
US2694963A (en) * 1949-04-08 1954-11-23 Patent & Licensing Corp Apparatus for the manufacture of waterproofed multiply sheets

Similar Documents

Publication Publication Date Title
US4177304A (en) Method of coating both sides of a travelling web
US2243604A (en) Device for applying films of coating material to paper webs
US2281340A (en) Paper coating device
US2411416A (en) Papermaking apparatus
US2046596A (en) Apparatus for uniformly coating flat surfaces
US1903325A (en) Paper coating method and apparatus
US3360393A (en) Method of making cockled paper
US2428113A (en) Machine for coating paper
CN114277608A (en) Five-roller coating machine and coating method thereof
US2257113A (en) Coating apparatus
US2105981A (en) Machine for applying mobile films
US1866689A (en) Method and apparatus for waxing paper
US3231418A (en) Coating a moving paper web with a coating roller having lower peripheral speed than web
US1747289A (en) Roll-shifting apparatus
US1921369A (en) Method of coating paper
US2287905A (en) Coating machine
US2244859A (en) Coating apparatus
US1759600A (en) Method and apparatus for treating coated material
US2093347A (en) Means for applying dope to paper
US1569064A (en) Web-treating machine
US2416789A (en) Apparatus for coating paper
US146240A (en) Improvement in paper-lining machines
US2024284A (en) Apparatus for making leather substitutes
US2712342A (en) Laminating machine for producing composite webs of paper
US1981321A (en) Laminated board making machine