CA1233068A - Roller and method of making same - Google Patents
Roller and method of making sameInfo
- Publication number
- CA1233068A CA1233068A CA000452331A CA452331A CA1233068A CA 1233068 A CA1233068 A CA 1233068A CA 000452331 A CA000452331 A CA 000452331A CA 452331 A CA452331 A CA 452331A CA 1233068 A CA1233068 A CA 1233068A
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- support member
- inner sleeve
- roller
- sleeve support
- preformed
- Prior art date
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Abstract
IMPROVED ROLLER AND METHOD OF MAKING SAME
Abstract of the Disclosure A commercial roller which includes an improved preformed roller cover and a central core is described wherein the preformed cover incorporates a novel inner sleeve support member having an extended surface area for providing increased adhesion and reduced bonding failure both with respect to an outer elastomeric cover and to the inner core. The novel inner sleeve has a corrugated construction on both the interior and exterior surfaces thereof providing a series of alternating interior and exterior channels which increase the surface area available for chemical bonding and also provide positive mechanical barriers to assist bonding and reduce bond failure.
The roller can be assembled at point of use by mounting the improved preformed roller cover onto the central core.
Abstract of the Disclosure A commercial roller which includes an improved preformed roller cover and a central core is described wherein the preformed cover incorporates a novel inner sleeve support member having an extended surface area for providing increased adhesion and reduced bonding failure both with respect to an outer elastomeric cover and to the inner core. The novel inner sleeve has a corrugated construction on both the interior and exterior surfaces thereof providing a series of alternating interior and exterior channels which increase the surface area available for chemical bonding and also provide positive mechanical barriers to assist bonding and reduce bond failure.
The roller can be assembled at point of use by mounting the improved preformed roller cover onto the central core.
Description
i~306B
ye ification The present invention generally relates to commercial rollers, such as printer's rollers, of the type which can be assembled at point of use by mounting a preformed roller cover onto a roller core and to methods ox making such rollers. More particularly, this invention is directed to an improved preformed cover which incorporates a novel sleeve having an extended surface area for providing increased adhesion and reduced bonding failure both with respect to an outer elastomeric cover and to the inner core. In this regard, an important aspect of the present invention concerns a novel roller cover construction especially suited for use with printer's rollers, which roller cover construction utilizes a novel radially expandable fabric sleeve characterized by a series of alternating interior and exterior axially extending alternating ridges and furrows on the interior an exterior surfaces of the fabric sleeve that provide the finished roller with significantly reduced operational failures an I improved manufacturing economics.
Heretofore, printer' it rollers and methods for making printer's rollers have involved a wide variety of constructions and procedures including, for example:
casting rubber, urethane or other suitable materials onto a central roller core: wrapping of calendered sheets of a suitable material such as rubber, onto a central roller core and then vulcanizing the material; extruding a hot strip of an elastomeric material r wrapping it upon a core, and vulcanizing the material; wrapping a cold strip of material upon a core and curing or vulcanizing the material; and, shrink fitting certain polymers onto a YO-YO -~33~
central core. Each of these particular rollers and methods have the disadvantage ox being expensive to refinish when worn or damaged since the entire roller, including the heavy metal core, must be returned to the manufacturer.
One effort to overcome these disadvantages of such rollers is described in United States Letters Patent No. 3,184,355 and involves the use of a preformed outer cover which includes an outer annular sleeve of extruded rubber which is vulcanized to a liner of stretched knitted cotton fabric of uniform thickness. This outer cover can be shipped to the point of use and adhered to a stripped metal core, when replacement of the previous core is required. Typically, the preformed cover is mounted upon the metal core by thoroughly saturating the inner fabric lining with a suitable metal-fabric adhesive, slipping the cover over the core and allowing it to set.
Rollers of this later type allow assembly at point of use and greatly reduce the expense an time required for transporting preassembled rollers between manufacturing or repair centers and end use locations.
Thus machinery down time which can be extremely expensive, whether due to roller failure or maintenance programs, can be greatly reduced. on addition to the economic advantage of facilitating repair and maintaining of a roller at maximum operating efficiency at a location remote from the place of manufacture, rollers of the type described in the 355 patent provided an improved roller by virtue of the outer rubber sleeve being completely homogeneous, free of seams, air bubbles and voids.
Despite the many advantages of the previously known rollers of the type having a preformed roller cover 33~
which can be assembled on site onto a roller core, a common difficulty has arisen with such rollers in web offset printing where high speeds and hysteresis heat build-ups can cause bond failure. During operation, these rollers typically encounter pressures, from either a web or another roller which compress the rubber and produce a shearing force which leads to potential bonding failures. The use of a rubber cement to secure the extruded rubber or other elast~mer to the outer fabric and the use of the metal-fabric adhesive to secure the sleeve to the core have been found to yield potential for boning failures at five different locations within a given roller. These include the interface between the elastomeric covering end the fabric sleeve, within the fabric sleeve itself, between the fabric sleeve and the inner adhesive, within the adhesive itself, and, between the adhesive and the core.
The present invention solves the problem of increasing the adhesion throughout the roller by providing an improved preformed cover having an outer elastomeric I sleeve of rubber or other suitable elastomeric material which is bonded to a novel corrugated "ribbed" construction characterized by a series of alternating ridges and furrows on both the interior and exterior surfaces of such fabric sleeve. This preformed cover can be applied to a metal core in the same manner as is described in the 355 patent.
A finished roller employing this improved preformed cover, however, features a unique interlocking between the outer elastomeric sleeve and the interiorly located metal-fabric adhesive which provides a many fold increase in the resistance to bond failure. In addition to the adhesion enhancements, the fabric sleeve component of the present 3~6~
invention is radially expandable, enabling a single size sleeve to accommodate a wide variety of core diameters which feature, when coupled with its requiring the use of less metal-fabric adhesive, results in substantial manufacturing economies.
It is, therefore, a general object of the present invention to provide an improved roller and method of making same.
Another object of the present invention is to provide an improved roller of the type which incorporates a preformed roller cover which cover utilizes as an important feature thereon, a unique sleeve of fabric or equivalent material which is characterized by a series of alternating interior and exterior axially extending ridges and furrows on both the interior and exterior surface thereof.
Another object of the present invention is to provide a novel roller construction which is particularly suited for high stress applications which incorporates a preformed cover that can be applied to a steel roller core at the point of use wherein the outer elastomeric sleeve component of such roller, when applied to the steel core, is characterized by a series ox adjacently-spaced interlocking ribs with the metal-fabric adhesive which is used to bond such preformed cover to the metal core.
Another object of the present invention is to provide an improved roller construction, particularly suited for use as a printer's roller, which is characterized by a significant reduction in operational failures and improved manufacturing economies.
Russ and other objects of the present invention will be apparent from the following detailed description ~;~33~6~
thereof, taken in conjunction with the accompanying drawing wherein:
Figure 1 is a perspective view of a preformed roller cover embodying the present invention with a partial cut away of the surface elastomers Figure 2 is a transverse cross-section of an assembled roller embodying the features of this invention.
Figure 3 is a longitudinal cross-sectional view along the line 3-3 of Figure 2.
The present invention is generally embodied in a commercial roller 10, which can be assembled at point of use by mounting a preformed roller cover 12 onto a central roller core 14. The preformed cover 12 includes an inner sleeve lining 16 and an elastomeric outer cover component 18. In accordance with the present invention, the inner sleeve lining 16 is corrugated having alternating ridges 20 and grooves 22 on both the interior and exterior surfaces thereof. These ridges and grooves provide the inner sleeve lining with an extended surface area and provide greater adhesion between the individual components within the roller, Turning now to a more detailed consideration of the present invention, which is shown in its preferred embodiment for the purpose of illustration an not limitation, Figure 2 depicts a transverse cross-section of a roller 10 embodying the present invention in assembled form The roller 10 is assembled by mounting a preformed cover 12 onto a central core 14. The preformed cover 12 is preferably constructed by stretching an inner sleeve lining 16 over a steel mandrel (not shown), applying a suitable elastomers adhesive 24 to the outer surface 26 of the ~233~
sleeve, applying an elastomeric outer cover component 18 to the treated sleeve and curing the same.
The inner sleeve lining 16 is generally of knitted construction and typically is composed of cotton, rayon, nylon, glass cloth, onion, Dacron wool and similar natural and synthetic fibrous materials as well as blends thereof. The preferred materials, however, are cotton or rayon In accordance with the present invention, the sleeve 16 has an inner annular surface 28 and an outer annular surface 30 radially spaced apart and integrally connected by side walls 32. In the preferred embodiment of the present invention, the inner sleeve lining 16 is of the corrugated "ribbed" construction with inner annular portion 28, outer annular portion 30, and side walls 32 forming alternating extended ridges 20 and grooves I on the outer annular surface and corresponding ridges and grooves aye and aye on the inner annular surface 28. Alternating ridges and grooves 20, 22 and aye, aye define longitudinally or axially running interior channels 34 an exterior channels 36. These interior channels 34 and exterior channels 36 not only increase the surface area available for chemical bonding but also provide positive mechanical barriers to assist bonding and reduce bond failure. In addition, the "ribbed' construction adds structure to the sleeve 16 and accommodates stretching and can fit a range of core diameters thus reducing the number of sizes of inner sleeve linings needed.
To form the preformed cover 12 of the present invention, a suitable length of "ribbed" inner sleeve lining 16 is stretched on a steel mandrel dimensioned substantially the same as the en use central core 14.
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suitable rubber adhesive 24 is applied to the stretched inner sleeve lining 16 by a conventional method such as painting. Suitable rubber adhesives 24 include uncured elastomers such as Bun N, natural rubber, neoprene, urethane, etc., in an appropriate solvent. Examples of appropriate solvents are methyl ethyl kitten for urethane and Tulane for Bun N. the rubber adhesive 24 is applied to the entire outer surface of the stretched sleeve 16, that is it is applied to the ridges 20, grooves 22, and side walls 32 to fully coat the exterior channels 36 with the rubber adhesive. Before proceeding to form the preformed cover 12, the rubber adhesive's solvent is allowed to evaporate.
To complete the formation of the preformed cover 12, an elastomeric outer component 18 is applied by conventional methods to the treated inner sleeve lining 16.
The elastomeric outer surface 18 can be composed of any one of the major families of elastomeric compositions such as natural rubber, tuna N, Neoprene, ethylene-propylene terpolymer, urethanes, silicones, styrenebutadiene rubber, etc. Conventional methods of application of the elastomers 18 include casting, calendering, and extrusion such as cross head or straight extrusion. The applied elastomeric outer component 18 and treated inner sleeve lining 16 are cured in a conventional manner such as by wrapping and vulcanizing the same in a steam autoclave to form the preformed cover 12.
The preformed cover 12 is removed from the mandrel and cut to appropriate length and may be used immediately, or may be stored or shipped for future use.
To mount the preformed cover 12 on the core 14, a i~3~6~3 sufficient quantity of adhesive is applied to the interior of the sleeve lining 16. Suitable adhesives for this purpose may be a two-part epoxy, a urethane, or other suitable metal-fabric bonding systems. The adhesive 38 is allowed to thoroughly saturate the inner fabric lining of sleeve 16. In this regard, the interior channels 34 allow the adhesive to more effectively run longitudinally to insure proper application and adhesion. While the adhesive 38 is still wet, the preformed cover 12 is slipped over the core 14. Core 14 is cylindrical and usually composed of a dimensionally stable material such as steel, aluminum, magnesium, wood, laminated construction or plastic. The assembled roller is allowed to stand overnight for curing or setting of the adhesive to form an effective bony between the core 14 and the inner portion of sleeve 16.
The roller is then ground, polished and trimmed in whatever manner necessary for the desired end application.
The assembled roller 10 embodying the Features of the present invention has a greater resistance to roller failure, particularly at high speeds, than a roller assembled from an ordinary knit sock preformed cover heretofore known. The construction of the interior channels 34 and exterior channels 36 of the "ribbed"
interior sleeve lining 16 of the present invention not only increases the surface area of the interior sleeve lining 16 but the interlocked interior ribs also serve as mechanical barriers and structural support for the elas$omeric outer component 18~ adhesive 38 and the inner sleeve 16 itself.
The exterior channels 36 increase the surface area available for bonding to the elastomeric outer surface ~233~6~
18 and the exterior surface of side walls 32 provide barriers to the elastomers to strengthen the elastomeric bond against shearing. The interior channels 34 similarly provide an increased surface area for increasing the adhesion between the adhesive 38 and the inner sleeve 16.
The adhesive 38 fills the inner channels 34 which increases the structural support of the adhesive 38 and reduces bony failure within the adhesive Furthermore, the interior channels 34 allow the adhesive to more effectively run longitudinally on a roil surface improving adhesion with the central core and reducing bonding failures.
The increase in surface area and the number of barriers, "ribs," will depend, of course, upon the number of interior and exterior channels provided by the "ribbed"
inner sleeve lining 16. In accordance with the present invention, the interior channels 34 and exterior channels 36 run the entire axial length of the preformed cover 12 and preferably increase the surface area of the inner sleeve lining 16 prom 1.25 times the surface area of a conventional loop constructed interior lining, to more preferably at least around 105 times and most preferably at least around 2 times the surface area of a conventional non ribbed inner sleeve construction.
The limiting factor governing the life of a roller as a function of shearing force of the previously constructed rollers of the type assembled on site by mounting a preformed roller cover onto a roller core wherein the preformed roller cover had a conventional loop sleeve construction was typically boning failures either 3Q between the elastomers and the inner sleeve, within the inner sleeve itself, between the inner sleeve and the go ~Z33~6~
adhesive, within the adhesive itself or between the adhesive and the central core. However, with a roller constructed in accordance with the present invention the limiting factor determining failure of the roller will commonly be that the rubber strength of the elastomers was exceeded before the adhesion fails. thus a roller in accordance with the present invention yields all the advantages of rollers of the type which can be assembled at point of use by mounting a preformed roller cover onto a roller core with the added advantages of longer life and greater shear resistance.
The following examples describe the method of making various improved rollers in accordance with the present invention and the advantages thereof. These examples are set forth for purposes of illustration an are not to be construed as limitations on the present invention.
SAMPLE I
Two steel cores, 5" in face length and 5" in diameter, were grit blasted. A 27 Shore A Dormitory Vinyl Nitrite stock was compounded on a mill an then calendered into thicknesses of approximately 1/16". In System A roller, a 5" steel mandrel was used as a means of supporting an ordinary loop sock such as that described in U.S. Patent No, 3,184,355. The sock was painted with an elastomeric adhesive and the solvent allowed to evaporate. The vinyl nitrite stock was wrapped around this mandrel to a wall thickness of just over 1/2". This mandrel ~;~336~
then was wrapped with a non woven paper tape and vulcanized for 6 hours at 290F. using an open steam vulcanizer.
The System B roller was prepared in a similar fashion except the sock used was that of a corrugated construction in accordance with the present invention having approximately twice the surface area of the conventional loop sock construction. Each of the ribs in this example was four millimeters in width and two millimeters in height. After vulcanization, the tubes were coated in the interior sections with a Bisphenol-A-Epichlorohydrin epoxy resin using an aliphaticamine cure.
After affixing to a 511 diameter steel core, both the rollers of Systems A and B
were allowed to cure for 48 hours at approximately 75F. The cores prepared in this fashion were then ground using a conventional lathe, polished and then trimmed. The wall thicknesses of the finished structures were 1/4". The overall diameters of both were 5 1/2".
Each covered roll was tested in a specially designed hysteresis test machine which has pressure applied to the roll at constant speeds. The roll against which the test rolls were run was 4 1/2" in diameter.
At the start of each test, an initial pressure of approximately 10 pounds per ~233~68 linear inch was applied. The speed way maintained at 500 surface feet per minute The tests were continued until a pressure of 350 pounds per linear inch was attained on each of the samples. Both samples failed at this high pressure. The rate of pressure increase was approximately 25 pounds per linear inch for each 10 minute time period.
The normal loop sock construction showed a failure between the rubber and the sock with a complete and total separation of the rubber from the sock. In the rib construction, the failure occurred essentially at the tops of the ribs, however, approximately 40% of the rubber was still tightly adhesively bonded to the sock.
The failure in the conventional ordinary loop sock construction was an adhesive failure while the failure in the rib sock construction of the present invention was that of rubber shear failure, i.e. the limits of the rubber strength were exceeded. This example illustrates the superior adhesive bonding and barrier protection of a roller constructed in accordance with the present invention.
test was conducted to compare the sheer strength of a roller constructed from an ordinary loop sock such as that described in U.S. Patent No. 3,184,355, without an 3~6~
elastomeric over layer, and that of a roller constructed from a sock of a corrugated construction in accordance with the present invention, as described in Example 1, without an elastomeric over layer. The rollers were constructed by saturating the interior of each of the socks with epoxy and then stretching the socks over respective 5"
diameter x 5" face length cores an curing same.
Each of the sock covered cores was tested in the specially designed hysteresis test machine of Example 1 which applies pressure at constant speeds. At the start of each test, an initial pressure of approximately 10 pounds per linear inch was applied. The speed was maintainer at 500 surface feet per minute. The rate of pressure increase was approximately 2.5 I pounds per linear inch per minute until failure.
The roller constructed from an ordinary loop sock failed at 350 pounds per linear inch with an epoxy to sock separation.
The roller constructed from the corrugated sock of the present invention failed at 500 pounds per linear inch with epoxy being left on the core an on the fabric indicating the failure was due to sheer in the epoxy.
I
This example illustrates the marked improvement in the metal to fabric bond of a roller constructed in accordance with the present invention compared to that of a roller constructed with an ordinary loop sock construction.
A cotton sock of corrugated construction is stretched over a two inch diameter steel mandrel approximately three feet long. The sock is painted with a urethane dissolved in methyl ethyl kitten and the solvent is allowed to evaporate.
The mandrel is mounted into a mold and a one-part urethane such as Arnco's Catapol is poured in. The composition is cured for seven (7) hours at 2750F. The article is removed from the mold and the mandrel taken therefrom. To the interior of the preformed cover thus prepared is applied a two-part epoxy such as Shell's Eon 828 and General Mills' Versamid 140. The proportions are approximately 50-50. The preformed cover is affixed to a steel core and allowed to cure for 48 hours at 70F. Upon adhesive curing, the core is mounted in a lathe and ground to a smooth finish. The ends are trimmed and the roller is ready for use.
A cotton sock of corrugated construction is stretched over a 2 inch diameter steel I
mandrel approximately 3 feet long. The sock is painted with a rubber adhesive such as Bun N dissolved in Tulane and the solvent is allowed to evaporate. A Pun N stock with curing agents is milled and then calendered to sheets approximately 1/16 inch thick. The calendered sheets are applied to the mandrel sleeve construction. The composition is wrapped with nylon tape end lo the article is put in a vulcanizer and cured with open steam for six hours at 2900F.
Jon removal from the vulcanizer, the mandrel is taken off and the article is cooled. The preformed cover is then covered with epoxy in the interior sections an slipped upon the steel core. After allowing the adhesive to set for 48 hours at foe the roller is ground and polished.
FXAMPL~ 5 I A cotton sock of corrugated construction is stretched over a steel mandrel. The sock is painted with a vinyl nitrite composition dissolved in Tulane arc the solvent is allowed to evaporate. A
vinyl nitrite composition is filled with a cotton flock. The cotton flock in composition is mixed in a mill. This composition is next fed into an extrude pitted with a cross head. The steel mandrel with stretched ribbed sleeve over it is passed through the cross head and the flock 1 Z~33~36B
composition is extruded on this material.
The extruded part it then wrapped with a nylon tape and vulcanized for six hours in live team at OFF. Upon removal from the vulcanizer, the article is cowled and the steel mandrel removed. Next an epoxy adhesive is applied to the interior portions of the tube and the composition is slipped into a steel core. After allowing curing for 48 hours at 70F., the finished article is ground to yield the roller within the nap finish.
While in the foregoing specification certain embodiments of this invention have been described in detail, it will by appreciated that modifications an variations therefrom will be apparent to those skilled in the art. accordingly, this invention is to be limiter only by the scope of the appended claims.
ye ification The present invention generally relates to commercial rollers, such as printer's rollers, of the type which can be assembled at point of use by mounting a preformed roller cover onto a roller core and to methods ox making such rollers. More particularly, this invention is directed to an improved preformed cover which incorporates a novel sleeve having an extended surface area for providing increased adhesion and reduced bonding failure both with respect to an outer elastomeric cover and to the inner core. In this regard, an important aspect of the present invention concerns a novel roller cover construction especially suited for use with printer's rollers, which roller cover construction utilizes a novel radially expandable fabric sleeve characterized by a series of alternating interior and exterior axially extending alternating ridges and furrows on the interior an exterior surfaces of the fabric sleeve that provide the finished roller with significantly reduced operational failures an I improved manufacturing economics.
Heretofore, printer' it rollers and methods for making printer's rollers have involved a wide variety of constructions and procedures including, for example:
casting rubber, urethane or other suitable materials onto a central roller core: wrapping of calendered sheets of a suitable material such as rubber, onto a central roller core and then vulcanizing the material; extruding a hot strip of an elastomeric material r wrapping it upon a core, and vulcanizing the material; wrapping a cold strip of material upon a core and curing or vulcanizing the material; and, shrink fitting certain polymers onto a YO-YO -~33~
central core. Each of these particular rollers and methods have the disadvantage ox being expensive to refinish when worn or damaged since the entire roller, including the heavy metal core, must be returned to the manufacturer.
One effort to overcome these disadvantages of such rollers is described in United States Letters Patent No. 3,184,355 and involves the use of a preformed outer cover which includes an outer annular sleeve of extruded rubber which is vulcanized to a liner of stretched knitted cotton fabric of uniform thickness. This outer cover can be shipped to the point of use and adhered to a stripped metal core, when replacement of the previous core is required. Typically, the preformed cover is mounted upon the metal core by thoroughly saturating the inner fabric lining with a suitable metal-fabric adhesive, slipping the cover over the core and allowing it to set.
Rollers of this later type allow assembly at point of use and greatly reduce the expense an time required for transporting preassembled rollers between manufacturing or repair centers and end use locations.
Thus machinery down time which can be extremely expensive, whether due to roller failure or maintenance programs, can be greatly reduced. on addition to the economic advantage of facilitating repair and maintaining of a roller at maximum operating efficiency at a location remote from the place of manufacture, rollers of the type described in the 355 patent provided an improved roller by virtue of the outer rubber sleeve being completely homogeneous, free of seams, air bubbles and voids.
Despite the many advantages of the previously known rollers of the type having a preformed roller cover 33~
which can be assembled on site onto a roller core, a common difficulty has arisen with such rollers in web offset printing where high speeds and hysteresis heat build-ups can cause bond failure. During operation, these rollers typically encounter pressures, from either a web or another roller which compress the rubber and produce a shearing force which leads to potential bonding failures. The use of a rubber cement to secure the extruded rubber or other elast~mer to the outer fabric and the use of the metal-fabric adhesive to secure the sleeve to the core have been found to yield potential for boning failures at five different locations within a given roller. These include the interface between the elastomeric covering end the fabric sleeve, within the fabric sleeve itself, between the fabric sleeve and the inner adhesive, within the adhesive itself, and, between the adhesive and the core.
The present invention solves the problem of increasing the adhesion throughout the roller by providing an improved preformed cover having an outer elastomeric I sleeve of rubber or other suitable elastomeric material which is bonded to a novel corrugated "ribbed" construction characterized by a series of alternating ridges and furrows on both the interior and exterior surfaces of such fabric sleeve. This preformed cover can be applied to a metal core in the same manner as is described in the 355 patent.
A finished roller employing this improved preformed cover, however, features a unique interlocking between the outer elastomeric sleeve and the interiorly located metal-fabric adhesive which provides a many fold increase in the resistance to bond failure. In addition to the adhesion enhancements, the fabric sleeve component of the present 3~6~
invention is radially expandable, enabling a single size sleeve to accommodate a wide variety of core diameters which feature, when coupled with its requiring the use of less metal-fabric adhesive, results in substantial manufacturing economies.
It is, therefore, a general object of the present invention to provide an improved roller and method of making same.
Another object of the present invention is to provide an improved roller of the type which incorporates a preformed roller cover which cover utilizes as an important feature thereon, a unique sleeve of fabric or equivalent material which is characterized by a series of alternating interior and exterior axially extending ridges and furrows on both the interior and exterior surface thereof.
Another object of the present invention is to provide a novel roller construction which is particularly suited for high stress applications which incorporates a preformed cover that can be applied to a steel roller core at the point of use wherein the outer elastomeric sleeve component of such roller, when applied to the steel core, is characterized by a series ox adjacently-spaced interlocking ribs with the metal-fabric adhesive which is used to bond such preformed cover to the metal core.
Another object of the present invention is to provide an improved roller construction, particularly suited for use as a printer's roller, which is characterized by a significant reduction in operational failures and improved manufacturing economies.
Russ and other objects of the present invention will be apparent from the following detailed description ~;~33~6~
thereof, taken in conjunction with the accompanying drawing wherein:
Figure 1 is a perspective view of a preformed roller cover embodying the present invention with a partial cut away of the surface elastomers Figure 2 is a transverse cross-section of an assembled roller embodying the features of this invention.
Figure 3 is a longitudinal cross-sectional view along the line 3-3 of Figure 2.
The present invention is generally embodied in a commercial roller 10, which can be assembled at point of use by mounting a preformed roller cover 12 onto a central roller core 14. The preformed cover 12 includes an inner sleeve lining 16 and an elastomeric outer cover component 18. In accordance with the present invention, the inner sleeve lining 16 is corrugated having alternating ridges 20 and grooves 22 on both the interior and exterior surfaces thereof. These ridges and grooves provide the inner sleeve lining with an extended surface area and provide greater adhesion between the individual components within the roller, Turning now to a more detailed consideration of the present invention, which is shown in its preferred embodiment for the purpose of illustration an not limitation, Figure 2 depicts a transverse cross-section of a roller 10 embodying the present invention in assembled form The roller 10 is assembled by mounting a preformed cover 12 onto a central core 14. The preformed cover 12 is preferably constructed by stretching an inner sleeve lining 16 over a steel mandrel (not shown), applying a suitable elastomers adhesive 24 to the outer surface 26 of the ~233~
sleeve, applying an elastomeric outer cover component 18 to the treated sleeve and curing the same.
The inner sleeve lining 16 is generally of knitted construction and typically is composed of cotton, rayon, nylon, glass cloth, onion, Dacron wool and similar natural and synthetic fibrous materials as well as blends thereof. The preferred materials, however, are cotton or rayon In accordance with the present invention, the sleeve 16 has an inner annular surface 28 and an outer annular surface 30 radially spaced apart and integrally connected by side walls 32. In the preferred embodiment of the present invention, the inner sleeve lining 16 is of the corrugated "ribbed" construction with inner annular portion 28, outer annular portion 30, and side walls 32 forming alternating extended ridges 20 and grooves I on the outer annular surface and corresponding ridges and grooves aye and aye on the inner annular surface 28. Alternating ridges and grooves 20, 22 and aye, aye define longitudinally or axially running interior channels 34 an exterior channels 36. These interior channels 34 and exterior channels 36 not only increase the surface area available for chemical bonding but also provide positive mechanical barriers to assist bonding and reduce bond failure. In addition, the "ribbed' construction adds structure to the sleeve 16 and accommodates stretching and can fit a range of core diameters thus reducing the number of sizes of inner sleeve linings needed.
To form the preformed cover 12 of the present invention, a suitable length of "ribbed" inner sleeve lining 16 is stretched on a steel mandrel dimensioned substantially the same as the en use central core 14.
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suitable rubber adhesive 24 is applied to the stretched inner sleeve lining 16 by a conventional method such as painting. Suitable rubber adhesives 24 include uncured elastomers such as Bun N, natural rubber, neoprene, urethane, etc., in an appropriate solvent. Examples of appropriate solvents are methyl ethyl kitten for urethane and Tulane for Bun N. the rubber adhesive 24 is applied to the entire outer surface of the stretched sleeve 16, that is it is applied to the ridges 20, grooves 22, and side walls 32 to fully coat the exterior channels 36 with the rubber adhesive. Before proceeding to form the preformed cover 12, the rubber adhesive's solvent is allowed to evaporate.
To complete the formation of the preformed cover 12, an elastomeric outer component 18 is applied by conventional methods to the treated inner sleeve lining 16.
The elastomeric outer surface 18 can be composed of any one of the major families of elastomeric compositions such as natural rubber, tuna N, Neoprene, ethylene-propylene terpolymer, urethanes, silicones, styrenebutadiene rubber, etc. Conventional methods of application of the elastomers 18 include casting, calendering, and extrusion such as cross head or straight extrusion. The applied elastomeric outer component 18 and treated inner sleeve lining 16 are cured in a conventional manner such as by wrapping and vulcanizing the same in a steam autoclave to form the preformed cover 12.
The preformed cover 12 is removed from the mandrel and cut to appropriate length and may be used immediately, or may be stored or shipped for future use.
To mount the preformed cover 12 on the core 14, a i~3~6~3 sufficient quantity of adhesive is applied to the interior of the sleeve lining 16. Suitable adhesives for this purpose may be a two-part epoxy, a urethane, or other suitable metal-fabric bonding systems. The adhesive 38 is allowed to thoroughly saturate the inner fabric lining of sleeve 16. In this regard, the interior channels 34 allow the adhesive to more effectively run longitudinally to insure proper application and adhesion. While the adhesive 38 is still wet, the preformed cover 12 is slipped over the core 14. Core 14 is cylindrical and usually composed of a dimensionally stable material such as steel, aluminum, magnesium, wood, laminated construction or plastic. The assembled roller is allowed to stand overnight for curing or setting of the adhesive to form an effective bony between the core 14 and the inner portion of sleeve 16.
The roller is then ground, polished and trimmed in whatever manner necessary for the desired end application.
The assembled roller 10 embodying the Features of the present invention has a greater resistance to roller failure, particularly at high speeds, than a roller assembled from an ordinary knit sock preformed cover heretofore known. The construction of the interior channels 34 and exterior channels 36 of the "ribbed"
interior sleeve lining 16 of the present invention not only increases the surface area of the interior sleeve lining 16 but the interlocked interior ribs also serve as mechanical barriers and structural support for the elas$omeric outer component 18~ adhesive 38 and the inner sleeve 16 itself.
The exterior channels 36 increase the surface area available for bonding to the elastomeric outer surface ~233~6~
18 and the exterior surface of side walls 32 provide barriers to the elastomers to strengthen the elastomeric bond against shearing. The interior channels 34 similarly provide an increased surface area for increasing the adhesion between the adhesive 38 and the inner sleeve 16.
The adhesive 38 fills the inner channels 34 which increases the structural support of the adhesive 38 and reduces bony failure within the adhesive Furthermore, the interior channels 34 allow the adhesive to more effectively run longitudinally on a roil surface improving adhesion with the central core and reducing bonding failures.
The increase in surface area and the number of barriers, "ribs," will depend, of course, upon the number of interior and exterior channels provided by the "ribbed"
inner sleeve lining 16. In accordance with the present invention, the interior channels 34 and exterior channels 36 run the entire axial length of the preformed cover 12 and preferably increase the surface area of the inner sleeve lining 16 prom 1.25 times the surface area of a conventional loop constructed interior lining, to more preferably at least around 105 times and most preferably at least around 2 times the surface area of a conventional non ribbed inner sleeve construction.
The limiting factor governing the life of a roller as a function of shearing force of the previously constructed rollers of the type assembled on site by mounting a preformed roller cover onto a roller core wherein the preformed roller cover had a conventional loop sleeve construction was typically boning failures either 3Q between the elastomers and the inner sleeve, within the inner sleeve itself, between the inner sleeve and the go ~Z33~6~
adhesive, within the adhesive itself or between the adhesive and the central core. However, with a roller constructed in accordance with the present invention the limiting factor determining failure of the roller will commonly be that the rubber strength of the elastomers was exceeded before the adhesion fails. thus a roller in accordance with the present invention yields all the advantages of rollers of the type which can be assembled at point of use by mounting a preformed roller cover onto a roller core with the added advantages of longer life and greater shear resistance.
The following examples describe the method of making various improved rollers in accordance with the present invention and the advantages thereof. These examples are set forth for purposes of illustration an are not to be construed as limitations on the present invention.
SAMPLE I
Two steel cores, 5" in face length and 5" in diameter, were grit blasted. A 27 Shore A Dormitory Vinyl Nitrite stock was compounded on a mill an then calendered into thicknesses of approximately 1/16". In System A roller, a 5" steel mandrel was used as a means of supporting an ordinary loop sock such as that described in U.S. Patent No, 3,184,355. The sock was painted with an elastomeric adhesive and the solvent allowed to evaporate. The vinyl nitrite stock was wrapped around this mandrel to a wall thickness of just over 1/2". This mandrel ~;~336~
then was wrapped with a non woven paper tape and vulcanized for 6 hours at 290F. using an open steam vulcanizer.
The System B roller was prepared in a similar fashion except the sock used was that of a corrugated construction in accordance with the present invention having approximately twice the surface area of the conventional loop sock construction. Each of the ribs in this example was four millimeters in width and two millimeters in height. After vulcanization, the tubes were coated in the interior sections with a Bisphenol-A-Epichlorohydrin epoxy resin using an aliphaticamine cure.
After affixing to a 511 diameter steel core, both the rollers of Systems A and B
were allowed to cure for 48 hours at approximately 75F. The cores prepared in this fashion were then ground using a conventional lathe, polished and then trimmed. The wall thicknesses of the finished structures were 1/4". The overall diameters of both were 5 1/2".
Each covered roll was tested in a specially designed hysteresis test machine which has pressure applied to the roll at constant speeds. The roll against which the test rolls were run was 4 1/2" in diameter.
At the start of each test, an initial pressure of approximately 10 pounds per ~233~68 linear inch was applied. The speed way maintained at 500 surface feet per minute The tests were continued until a pressure of 350 pounds per linear inch was attained on each of the samples. Both samples failed at this high pressure. The rate of pressure increase was approximately 25 pounds per linear inch for each 10 minute time period.
The normal loop sock construction showed a failure between the rubber and the sock with a complete and total separation of the rubber from the sock. In the rib construction, the failure occurred essentially at the tops of the ribs, however, approximately 40% of the rubber was still tightly adhesively bonded to the sock.
The failure in the conventional ordinary loop sock construction was an adhesive failure while the failure in the rib sock construction of the present invention was that of rubber shear failure, i.e. the limits of the rubber strength were exceeded. This example illustrates the superior adhesive bonding and barrier protection of a roller constructed in accordance with the present invention.
test was conducted to compare the sheer strength of a roller constructed from an ordinary loop sock such as that described in U.S. Patent No. 3,184,355, without an 3~6~
elastomeric over layer, and that of a roller constructed from a sock of a corrugated construction in accordance with the present invention, as described in Example 1, without an elastomeric over layer. The rollers were constructed by saturating the interior of each of the socks with epoxy and then stretching the socks over respective 5"
diameter x 5" face length cores an curing same.
Each of the sock covered cores was tested in the specially designed hysteresis test machine of Example 1 which applies pressure at constant speeds. At the start of each test, an initial pressure of approximately 10 pounds per linear inch was applied. The speed was maintainer at 500 surface feet per minute. The rate of pressure increase was approximately 2.5 I pounds per linear inch per minute until failure.
The roller constructed from an ordinary loop sock failed at 350 pounds per linear inch with an epoxy to sock separation.
The roller constructed from the corrugated sock of the present invention failed at 500 pounds per linear inch with epoxy being left on the core an on the fabric indicating the failure was due to sheer in the epoxy.
I
This example illustrates the marked improvement in the metal to fabric bond of a roller constructed in accordance with the present invention compared to that of a roller constructed with an ordinary loop sock construction.
A cotton sock of corrugated construction is stretched over a two inch diameter steel mandrel approximately three feet long. The sock is painted with a urethane dissolved in methyl ethyl kitten and the solvent is allowed to evaporate.
The mandrel is mounted into a mold and a one-part urethane such as Arnco's Catapol is poured in. The composition is cured for seven (7) hours at 2750F. The article is removed from the mold and the mandrel taken therefrom. To the interior of the preformed cover thus prepared is applied a two-part epoxy such as Shell's Eon 828 and General Mills' Versamid 140. The proportions are approximately 50-50. The preformed cover is affixed to a steel core and allowed to cure for 48 hours at 70F. Upon adhesive curing, the core is mounted in a lathe and ground to a smooth finish. The ends are trimmed and the roller is ready for use.
A cotton sock of corrugated construction is stretched over a 2 inch diameter steel I
mandrel approximately 3 feet long. The sock is painted with a rubber adhesive such as Bun N dissolved in Tulane and the solvent is allowed to evaporate. A Pun N stock with curing agents is milled and then calendered to sheets approximately 1/16 inch thick. The calendered sheets are applied to the mandrel sleeve construction. The composition is wrapped with nylon tape end lo the article is put in a vulcanizer and cured with open steam for six hours at 2900F.
Jon removal from the vulcanizer, the mandrel is taken off and the article is cooled. The preformed cover is then covered with epoxy in the interior sections an slipped upon the steel core. After allowing the adhesive to set for 48 hours at foe the roller is ground and polished.
FXAMPL~ 5 I A cotton sock of corrugated construction is stretched over a steel mandrel. The sock is painted with a vinyl nitrite composition dissolved in Tulane arc the solvent is allowed to evaporate. A
vinyl nitrite composition is filled with a cotton flock. The cotton flock in composition is mixed in a mill. This composition is next fed into an extrude pitted with a cross head. The steel mandrel with stretched ribbed sleeve over it is passed through the cross head and the flock 1 Z~33~36B
composition is extruded on this material.
The extruded part it then wrapped with a nylon tape and vulcanized for six hours in live team at OFF. Upon removal from the vulcanizer, the article is cowled and the steel mandrel removed. Next an epoxy adhesive is applied to the interior portions of the tube and the composition is slipped into a steel core. After allowing curing for 48 hours at 70F., the finished article is ground to yield the roller within the nap finish.
While in the foregoing specification certain embodiments of this invention have been described in detail, it will by appreciated that modifications an variations therefrom will be apparent to those skilled in the art. accordingly, this invention is to be limiter only by the scope of the appended claims.
Claims (27)
1. A preformed roller cover for mounting onto a roller core comprising an inner sleeve support member having a predefined axial length and an outer annular elastomeric cover bonded to said support member wherein said support member includes a plurality of circumferentially disposed, axially extending, alternating ridges and furrows on the interior and exterior surfaces of said support member, said alternating ridges and furrows defining internal and external channels, the support member surface defining said external channels being intimately bonded to integral axially extend-ing ribs on the interior surface of said outer elastomeric cover.
2. The preformed roller cover of claim 1 wherein said channels extend the entire axial length of said inner sleeve support member.
3. The preformed roller cover of claim 2 wherein said inner sleeve support member has a combined interior and exterior surface area which is at least 1.25 times that of a cylindrical sleeve of the same thickness.
4. The preformed roller cover of claim 2 wherein said inner sleeve support member has a combined interior and exterior surface area which is at least 1.5 times that of a cylindrical sleeve of the same thickness.
5. The preformed roller cover of claim 2 wherein said inner sleeve support member has a combined interior and exterior surface area which is approximately twice that of a cylindrical sleeve of the same thickness.
6. The preformed roller cover of claim 1 wherein said inner sleeve support member is composed of knitted fibrous material.
7. The preformed roller cover of claim 6 wherein said fibrous material is selected from the group consisting of cotton, wool, glass cloth, rayon, nylon, orlon and dacron fibrous materials and blends thereof.
8. The preformed roller cover of claim 6 wherein said inner sleeve support member is composed of a knitted natural fibrous material selected from the group consisting of cotton and wool fibrous materials.
9. The preformed roller cover of claim 6 wherein said inner sleeve support member is composed of a knitted synthetic fibrous material selected from the group consist-ing of rayon, nylon, orlon, dacron and glass cloth fibrous materials.
10. In a roller which includes a preformed roller cover, a cylindrical core, and a metal-fabric adhesive between the outer surface of said core and the inner surface of said preformed roller cover, the improvement wherein said preform-ed roller cover has an outer annular elastomeric cover which is bonded to an inner sleeve support member, said support mem-ber including a plurality of circumferentially disposed, axial-ly extending, alternating ridges and furrows on the interior and exterior surfaces of said support member, said alternat-ing ridges and furrows defining internal and external channels the support member surface defining said external channels being intimately bonded to integral axially extending ribs on the interior surface of said outer elastomeric cover, the support member surface defining said internal channels being intimately bonded to integral axially extending ribs formed in said metal-fabric adhesive.
11. The improved roller cover of claim 10 wherein said channels extend the entire axial length of said inner sleeve support member.
12. The improved roller of claim 11 wherein said inner sleeve support member has a combined interior and exterior surface area which is at least 1.25 times that of a cylindrical sleeve of the same thickness.
13. The improved roller of claim 11 wherein said inner sleeve support member has a combined interior and exterior surface area which is at least 1.5 times that of a cylindrical sleeve of the same thickness.
14. The improved roller of claim 11 wherein said inner sleeve support member has a combined interior and exterior surface area which is approximately twice that of a cylindrical sleeve of the same thickness.
15. The improved roller of claim 10 wherein said inner sleeve support member is composed of knitted fibrous material.
16. The improved roller of claim 15 wherein said fibrous material is selected from the group consisting of cotton, wool, glass cloth, rayon, nylon, orlon and dacron fibrous materials and blends thereof.
17. The improved roller of claim 15 wherein said inner sleeve support member is composed of a knitted natural fibrous material selected from the group consisting of cotton and wool fibrous materials.
18. The improved roller of claim 15 wherein said inner sleeve support member is composed of a knitted synthetic fibrous material selected from the group consisting of rayon, nylon, orlon, dacron and glass cloth fibrous materials.
19. In the method of making a commercial roller of the type wherein a preformed outer covering is formed by stretching a tubular inner sleeve support member onto a mandrel, coating said inner sleeve support member with an elastomeric adhesive, applying an elastomeric composition to said coated sleeve, curing said elastomeric composition to provide a preformed outer covering over said inner sleeve support member and removing the same from said mandrel, saturating said inner sleeve support member with a second adhesive, slipping said outer covering over a roller core and allowing said adhesive to set, finish grinding and polishing the outer peripheral surface of said covering, and trimming the ends of said covering to conform to the length of said core, the improvement wherein said inner sleeve support member includes a plurality of circumfer-entially disposed, axially extending, alternating ridges and furrows on the interior and exterior surfaces of said inner sleeve support member, said alternating ridges and furrows defining internal and external channels, the sup-port member surface defining said external channels being intimately bonded to integral axially extending ribs on the interior surface of said outer elastomeric cover and the support member surface defining said internal channels being intimately bonded to integral axially extending ribs formed in said second adhesive.
20. The method of claim 19 wherein said channels extend the entire axial length of said inner sleeve support member.
21. The method of claim 20 wherein said inner sleeve support member has a combined interior and exterior surface area which is at least 1.25 times that of a cylin-drical sleeve of the same thickness.
22. The method of claim 20 wherein said inner sleeve support member has a combined interior and exterior surface area which is at least 1.5 times that of a cylin-drical sleeve of the same thickness.
23. The method of claim 20 wherein said inner sleeve support member has a combined interior and exterior surface area which is approximately twice that of a cylin-drical sleeve of the same thickness.
24. The method of claim 19 wherein said inner sleeve support member is composed of a knitted natural or synthetic fibrous material and blends thereof.
25. The method of claim 24 wherein said natural or synthetic fibrous material is selected from the group consisting of cotton, wool, glass, cloth, rayon, nylon, orlon and dacron fibrous materials and blends thereof.
26. The method of claim 24 wherein said inner sleeve support member is composed of a knitted natural fibrous material selected from the group consisting of cotton and wool fibrous materials.
27. The method of claim 24 wherein said inner sleeve support member is composed of a knitted synthetic fibrous material selected from the group consisting of rayon, nylon, orlon, dacron and glass cloth fibrous materials.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US48619883A | 1983-04-18 | 1983-04-18 | |
| US486,198 | 1983-04-18 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1233068A true CA1233068A (en) | 1988-02-23 |
Family
ID=23930983
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000452331A Expired CA1233068A (en) | 1983-04-18 | 1984-04-18 | Roller and method of making same |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1233068A (en) |
-
1984
- 1984-04-18 CA CA000452331A patent/CA1233068A/en not_active Expired
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