US2987802A

US2987802A - Composition calender roll

Info

Publication number: US2987802A
Application number: US706322A
Authority: US
Inventors: Robert G Quinn
Original assignee: Johns Manville
Current assignee: Johns Manville Corp; Johns Manville
Priority date: 1957-12-31
Filing date: 1957-12-31
Publication date: 1961-06-13
Anticipated expiration: 1978-06-13

Description

June 13, 1961 RQG. QUINN 2,987,802

COMPOSITION CALENDER ROLL Filed Dec. 31, 1957 United States Patent 2,987,802 COMPOSITION CALENDER ROLL Robert Quinn, Bound Brook, NJ., assignor to Johns- Manvllle Corporation, New York, N.Y., a corporation of New York Filed Dec. 31, 1957, Ser. No. 706,322 Claims. (Cl. 29-125) This invention relates to a composition roll primarily for use in paper calenders wherein the composition roll combines with a chilled iron roll or other conventional roll to produce a polishing action on the paper.

A paper calender has a plurality of vertically mounted chilled iron rolls or similarly functioning rolls between which are composition rolls. The weight of the chilled iron rolls, usually augmented by additional force, causes an indentation in the nip between each chilled iron roll and each composition roll resulting in a speed difierential between the chilled iron rolls and the composition roll. The paper/to be polished is fed between these rolls so that the sliding frictional polishing action, caused by the speed differential between each chilled iron roll and associated composition roll, produces a high gloss on the paper. A major problem in these machines is the ability of the composition rolls to withstand the high heat in the nip between the chilled iron roll and associated composition roll and the shock impact of being repeatedly compressed by the chilled iron rolls. Also, the composition rolls have to be able to withstand surface indentations caused by occasional wrinkles occurring in the paper being processed. The composition rolls presently in use develo'p surface cracks caused by the heat, the repeated compression and the passage of the aforementioned wrinkles and must be removed from the calendar for remachining. Thus, there is an ever occurring need for remachining, which is a very expensive and time-consuming operation and shortens the life span of the composition roll. v

It is a primary object of this invention to provide a composition roll which will not readily deteriorate from the heat and the compressive forces prevalent in the nip between the composition rolls and the chilled iron rolls of a paper calender.

It is another object of this invention to provide a composition roll that will, after an indentation during normal operation, regain its original shape by continued operation so that it is not necessary to remove the roll for remachining.

It is a further object of this invention to provide a composition roll having high impact characteristics to withstand the constant compression and expansion forces found in a conventional paper calender.

It is another object of this invention to provide an asbestos composition roll for paper calenders that combines with a chilled iron roll to produce a sliding frictional polishing action on paper.

Briefly stated, the foregoing objects are accomplished in accordance with the instant invention by a composition roll made by pressing together a plurality of asbestos paper sheets into a roll. The asbestos paper is formed from long asbestos fibers sized with a suitable heat-resistant thermosetting resin such as a silicone resin. The fibers have been thoroughly cleaned, and the paper is generally free from pencils or fiber bundles or rock particles to avoid scratching the paper stock being calendered. The composition rolls composed of the asbestos paper cooperate with the chilled iron rolls of the paper calender to produce a sliding frictional polishing action on the paper being calendered. It is to be understood that the novel composition rolls of this invention have utility with conventional, similarly functioning paper calender rolls other than chilled iron rolls.

Patented June 13, 1961 The invention will be more fully understo'od and further objects and advantages thereof will become apparent when reference is made to the following detailed description of a preferred embodiment of the invention and the accompanying drawing in which:

FIG. 1 is a schematic representation of a paper calender;

FIG. 3 is a top plan view of a plurality of asbestos paper sheets arranged on a mandrel;

FIG. 4 is a side elevation of FIG. 3;

FIG. 5 is an end elevation of a composition roll mounted on a mandrel; and

FIG. 6 is a perspective view of a finished composition roll mounted on a mandrel.

Referring to the drawing, there is disclosed a preferred embodiment of the composition roll which in FIG. 1 is shown in operative position on a paper calender. The calender itself is one of a conventional nature and forms no part of the instant invention. A plurality of composition rolls 1 are mounted in position between chilled iron rolls 2. The

rolls

1 and 2 are rotatably mounted in the journal boxes 3 which are mounted for free vertical sliding movement in the frame 4. The lowest chilled iron roll 5 is much larger in diameter than the

other rolls

1 and 2 and is driven by a suitable source of power (not shown) in any conventional manner. The paper stock 6-to be calendered is mounted in position by any conventional support mechanism (not shown). The paper 7 after being calendered is formed into a roll 8 supported in a conventional mechanism (not shown). As illustrated in FIG. 1, the composition rolls 1 are indented at their juncture with the chilled iron rolls 2. This is due to the weight of the rolls which is usually augmented by additional downwardly directed force. The indenture at the nip between the chilled iron rolls 2 and the composition rolls 1 results in a speed difference between the rolls. This speed differential produces a sliding frictional polishing action on the paper stock 6 as it passes through the calender to produce the desired gloss on the paper 7. A plurality of tension rolls 9 are suitably mounted by any conventional mechanism (not shown) to provide proper tension on the paper as it passes through the calender. The composition rolls 1 may be used with any type of rolls 2 found in all conventional paper calenders.

Each of the composition rolls of the instant invention is formed as illustrated in FIGS. 26. An asbestos paper is made in any conventional manner such as from a slurry of asbestos fibers and a suitable binder and is cut into substantially fourteen inch octagon sheets 10 which are approximately thick. The size, shape and thickness of the sheets 10 are given for illustration purposes only and are not intended to limit the invention thereto. The sheets 10 are then assembled on a shaft 11 so that each sheet 10 is rotated approximately 22 /2" relative to the preceding sheet. The rotation of the successive sheets 10 assures that the fibers in the composition roll 1 will not be all oriented in the same direction. After the sheets 10 have been assembled in proper position on the shaft 11, they are subjected to an endwise compression force of about 10-15 tons per square inch so that the finished composition roll has a final density of approximately 105 p.c.f. The finished composition roll 1 desirably has a Durometer hardness B scale of to 90. The above figures are given for illustration purposes only and are not intended to limit the invention thereto.

After the sheets 10 have been pressed together, they are machined into a finished composition roll 1 having a cylindrical surface as illustrated in FIGS. 5 and 6. The composition roll is provided with a keyway 12 and is connected for rotation with the shaft 14 by the key 13. The

FIG. 2 is a top plan view of an asbestos paper sheett shaft 14 is mounted for rotation in a pair of the journal boxes 3. As illustrated in FIG. 1, the composition rolls 1 are constantly being compressed as they engage the chilled iron rolls 2. After the compression forces are removed, the composition rolls expand to regain their original radius. This elasticity of the composition rolls 1 is a desired and necessary property to produce the sliding frictional action on the paper. The composition rolls 1 have to be able to Withstand the heat and moisture prevailing in the nip between the composition rolls 1 and the chilled iron rolls 2. The temperature in this area is approximately 300 F. This heat results from the sliding frictional polishing action between the composition rolls and the chilled iron rolls and the heat generallyapplied to the chilled iron rolls; The fibers in the composition rolls now in use tend to deteriorate and become brittle under the above conditions. The constant compression and expansion forces on the ordinary composition rolls break the fibers therein, and the ordinary composition rolls develop surface cracks and surface abrasions which necessitate remachining. It has been found that a composition roll made from suitable asbestos fibers sized with a proper binder, has outstanding qualities to withstand these constant compression and expansion forces. A composition roll, made in accordance with the instant invention is not readily susceptible to cracks and surface abrasions which reduce the numerous remachining operations which are expensive and time-consuming.

A composition roll 1 of a desired nature is made from sheets 10, composed of long asbestos fiber sized with a heat-resistant thermosetting resin such as a silicone resin. The sheets are composed of long white asbestos that has been thoroughly cleaned. A composition roll 1 Was formed of sheets 10 in which the asbestos paper contained fibers of which not more than 30% were less than 200 mesh, and of the fibers were of +14 mesh. The

chilled iron rolls are generally heated while in operation to produce a desired result. Therefore, the binder in the composition rolls 1 is desirably thermosetting and not liquifiable under heat. The fibers forming the asbestos paper are sized with a heat-resistant thermosetting resin such as a silicone resin solution. By way of illustration only, a suitable silicone resin is Dow-Corning KER-6127 which is a 40% by weight aqueous emulsion "of a complex alkoxyl methyl polysiloxane, resin, a typical example of which is described in Example 1 of United States patent to Bass, No. 2,706,724, issued April 19, 1955. Another satisfactory resin is Dow-Corning XER-601'7 which is a 30% by Weight aqueous emulsion of a monoanylpolysil'oxane resin. The above silicone resins are thermosetting and sol-id at 300 F. The heat-resistant thermosetting resins are added to the slurry, from which the asbestos paper is conventionally made, in the rato of about 35% by weight of the asbestos fiber in the slurry. In a preferred embodiment, the aforementioned long asbestos fibers were sized with the above Dow-Corning KER-6127. As used in the specification and claims, the term, long asbestos fibers, means that of the asbestos fibers used therein not more than 30% were less than 200 mesh. An amount in weight of the Dow-Coming XER-6127 equal to approximately 4% by weight of the long, cleaned asbestos fibers was added to the slurry containing the as bestos fibers. The paper made therefrom was heat treated at approximately 550 to 600 F for 6 to 10' minutes before being cut into the octagon sheets 10. The above examples are given for iIIustration purposes only, and it is not intended to limit the invention thereto.

Another unobvious and highly desirable characteristic 7 of the composition rolls 1, made in accordance with the instant invention, is their ability to regain their original shape in normal operation. Many times the paper stock being fed will have a wrinkle therein. -As this wrinkle passes between a chilled iron roll 2 and an associated composition roll 1, an impression of the wrinkle is made in the surface of the composition roll. Composition rolls presently in use develop surface cracks due to these wrinkles and the operation of the calender has to be interrupted While the composition rolls are removed and remachined. However, the composition rolls of long asbestos fiber sized with a silicone resin have the abovementioned characteristics of regaining their original shape under normal operation. Therefore, when a wrinkle passes between a chilled iron roll 2 and an associated composition roll 1, made in accordance with the instant invention, it is not necessary to remove the composition roll for remachining. Under ordinary operating conditions, the composition rolls presently in use must be removed from the calender for remaching of surface cracks caused by wrinkles in the paper stock on an average between 2 and 3 times for every 24 hours of operation. The composition rolls of long asbestos fiber do not have to be removed for remachining of surface cracks due to wrinkles in the paper stock since these asbestos paper rolls regain their original shape after the Wrinkle passes through the nip between the chilled iron roll 2 and the composition roll 1. Thus, a tremendous saving in time and money is attained by use of the composition rolls of the instant invention.

The operation of the calender is as illustrated in FIG. 1. Paper from the roll of paper stock 6 is threaded around the top chilled iron roll and then successively downwardly around the composition rolls 1, the chilled iron rolls 2 and the tension rolls 9. The paper 7 is led from the lowest chilled iron roll 2 to the roll 8 where the finished polished paper is collected. The bottom roll 5 is rotatably driven at a speed dependent upon the quality of paper being processed. The chilled iron rolls 2 and the composition rolls 1 are rotated in the directions indicated by the arrows by their frictional interengagement. Thus, all the rolls derivetheir rotation from the driven roll 5. As illustrated in FIG. 1, the weight of the chilled iron rolls 2, augmented by additional pressure as desired, causes the composition rolls 1 to be indented at the nip between the chilled iron rolls and the composition rolls. This indentation results in a speed differential between the chilled iron rolls 2 and the composition rolls 1 to produce a sliding frictional polishing action on the paper stock.

Having thus described the invention in rather full detail, it will be understood that these details need not be strictly adhered to and that various changes and modifications may suggest themselves to one skilled in the art, all falling within the scope of the invention as defined by the, subjoined claims.

What I claim is:

l. A composition roll for calenders, comprising, in a consolidated, coherent, durable structural body, providing the calendering surface of the roll, a plurality of sheets of asbestos paper consisting essentially of long asbestos fibers sized with a heat-resistant thermosetting resin, said fibers being characterized as having at least 70% thereof greater than 200 mesh, the peripheral calendering surface of said body comprising the edges of said sheets.

2. A composition roll for calenders, comprising a plurality of sheets of asbestos paper consisting essentially of long asbestos fibers. sized with a heat-resistant resin, said fibers being characterized as having at least 70% thereof greater than 200 mesh, said sheets being pressed together flatwise to form a consolidated roll structure in which the edges of said sheets are integrated to form a peripheral calendering surface of the roll.

3. A composition roll for calenders comprising a roll consisting essentially of a plurality of sheets of asbestos paper, each of said sheets consisting essentially of long, cleaned asbestos fibers sized with; a suitable heat-resistant binder, said fibers being characterized as having at least 70% thereof greater than 200 mesh, each of said sheets having a central opening, and said sheets being pressed together with said openings aligned to form a roll.

4. A composition roll for calenders, comprising in a consolidated, coherent, durable structural body, providing the calendering surface of the roll, a plurality of sheets of asbestos paper consisting essentially of long asbestos fibers sized with a heat-resistant resin, said fibers being characterized as having at least 70% thereof greater than 200 mesh and at least 15% thereof greater than 14 mesh, the peripheral calendering surface of said body comprising the edges of said sheets.

5. A composition roll for calenders, comprising a plurality of sheets of asbestos paper consisting essentially of long asbestos fibers sized with a heat-resistant resin, said fibers being characterized as having at least 70% thereof greater than 200 mesh and at least 15% thereof greater References Cited in the file of this patent UNITED STATES PATENTS Fish Apr. 19, 1932.

OTHER REFERENCES G. E. Publication: What are Silicone Resins7", pg. 5, para. 4, filed Apr. 18, 1949.

. UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.- 2,987,802 f June 13, 1961 I Robert G Quinn v Q It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 3, line 32 after "asbestos" insert fiber column 3, line 52, for "rato" read ratio Signed and sealed this 21st day of November 1961."

(SEAL) Attest:

ERNEST W. SW IDER 1 DAVID L. LADD Attesting Officer I Commissioner of Patents USCOMM-DC

Claims

1. A COMPOSITION ROLL FOR CALENDERS, COMPRISING, IN A CONSOLIDATED, COHERENT, DURABLE STRUCTURAL BODY, PROVIDING THE CALENDERING SURFACE OF THE ROLL, A PLURALITY OF SHEETS OF ASBESTOS PAPER CONSISTING ESSENTIALLY OF LONG ASBESTOS FIBERS SIZED WITH A HEAT-RESISTANT THERMOSETTING RESIN, SAID FIBERS BEING CHARACTERIZED AS HAVING AT LEAST 70% THEREOF GREATER THAN 200 MESH, THE PERIPHERAL CALENDERING SURFACE OF SAID BODY COMPRISING THE EDGES OF SAID SHEETS.