Patent Application
20060090840
This disclosure relates in general to a method of fabricating a flexible belt that includes a thin profile seam having no undesirable seam region thickness or protrusions. More specifically, this disclosure relates to a method of creating a thin and smooth profile seam for flexible electrostatographic imaging member belts having a number of morphological improvements.
Flexible imaging member electrostatographic belts as disclosed in prior art examples below, are well known in the art. Typical flexible electrostatographic imaging member belts include, for example, photoreceptors for electrostatographic imaging systems, electroreceptors such as ionographic imaging members for electrographic imaging systems, and intermediate image transfer belts for transferring toner images in electrostatographic and electrographic imaging systems. These belts are usually formed by cutting a rectangular, a square, or a parallelogram shape sheet from a web containing at least one layer of thermoplastic polymeric material, overlapping opposite ends of the sheet, and joining the overlapped ends together to form a seam. The seam typically extends from one edge of the belt to the opposite edge.
Generally, seamed imaging belts comprise at least a flexible supporting substrate and at least one imaging layer comprising thermoplastic polymeric matrix material. The “imaging layer” as employed herein is defined as the dielectric imaging layer of an electroreceptor belt, the transfer layer of an imaging belt and, the charge transport layer of an electrostatographic belt. Thus, the thermoplastic polymeric matrix material in the imaging layer is located in the upper portion of a cross section of an electrostatographic imaging member belt, the substrate layer being in the lower portion of the cross section of the electrostatographic imaging member belt. However, typical seamed electrostatographic imaging member belts do also require an anti-curl back coating to render desired belt flatness.
Flexible seamed electrostatographic imaging member belts thus are multilayered and include the substrate layer, the electrically conductive layer, and in addition an optional hole blocking layer, an adhesive layer, a charge generating layer, and a charge transport layer. In some embodiments, they may also include an anti-curl back coating layer.
Typically, such flexible electrostatographic imaging member belts are prepared or fabricated from sheets cut from a continuous web of a flexible imaging member of the same composition. The sheets are generally rectangular or parallelogram in shape. All edges may be of the same length or one pair of parallel edges may be longer than the other pair of parallel edges. The sheets are formed into a belt by joining overlapping opposite marginal end regions of the sheet. A seam is typically produced in the overlapping marginal end regions at the point of joining. Joining may be effected by any suitable means. Typical joining techniques include welding (including ultrasonic), gluing, taping, heat fusing and the like.
For a seamed imaging belt to be acceptable, the seam must have acceptable mechanical strength, and the final image produced from across the seam must be comparable in quality to images formed across the remainder of the belt. This is a difficult task because the electrostatic properties across the seam depend on interrelated factors such as seam geometry, seam construction (such as adhesive beyond the seam), seam topology or morphology, seam thickness and thickness variations.
In addition to mechanical strength and electrical or electrostatic requirements, there are other problems when transferring toner images onto and off of a seam region of an imaging belt. For example, with most conventional seamed imaging belts, there is usually relatively poor cleaning around the seam region. To resolve this problem, the toner release and friction properties across the seam region have to be comparable to those of the rest of the belt. Furthermore, most prior art seamed imaging belts have a significant “step” where the belt overlaps to form the seam. That step can be as large as 75 microns. Such a step significantly interferes with transfer and cleaning. Thus if toner is transferred onto and off of the seam, the seam's friction, toner release, and topography are much more constrained than those of other seamed imaging belts.
From above it can be seen that a seam's topography is very important if one wants to form over its region or transfer therefrom, a toner image without significant degradation of the final toner image. Thickness variations and surface protrusions are detrimental characteristics of conventionally formed seams in such belts.
Conventional belts have the above problems because when a sheet of a an imaging belt material web is conventionally jointed, for example ultrasonically welded into a belt, the seam of the resulting multilayered electrostatographic imaging flexible member belt does create two splashings formed from the molten layers. One of the splashings is deposited at the top of the belt surface, and the other at the backside of the belt, adjacent to either side of the seam overlap. The conventionally jointed or welded seam of the belt may occasionally contain undesirable high protrusions such as peaks, ridges, spikes, and mounds.
For example, in U.S. Pat. No. 5,688,355 a method is disclosed for fabricating a flexible belt utilizing excimer laser ablation. In the method, a precision amount of material is removed from the bottom and the top of two opposite ends of a cut sheet of a web of a multi-layered imaging member prior to overlapping the two opposite ends and ultrasonically welding them into a seam. The resulting multi-layered imaging member belt has a welded seam and is claimed to have little added thickness and reduced amount of seam splashing formulation.
In addition, U.S. Pat. No. 6,453,783 discloses a method and apparatus for producing an endless flexible seamed belt using templates. A first form of the template is a mask template with a template aperture in the form of a puzzle cut pattern to be used in combination with an excimer laser. The template is placed between the excimer laser source and the belt material to be cut. As the excimer laser traverses the width of the belt, the laser forms a puzzle cut pattern on the belt. A second form of the template is a punch and die having patterned edges in the form of a puzzle cut pattern with extremely small nodes and kerfs. The cutting tolerances of the patterned edges make it necessary to fix the punch with respect to the die so that there is no misalignment of the punch and die between cutting operations. This is accomplished by resiliently fixing the punch to the die, rather than having the punch attached to the force generating assembly as in normal punch and die assemblies. Belt material is positioned between a stock gap between the punch and die and the force generating assembly is activated to provide the cutting force. Once the belt material is cut, the cutting force is removed and the force generating assembly returns to its retracted position. Both types of templates result in very clean cuts without deformation or distortion.
U.S. Pat. No. 6,368,440 discloses a flexible electrostatographic imaging member belt that comprises two ends with matching puzzle-cut patterns of fingers arranged to be joined. The belt is fabricated by a method comprising the steps of: first, joining the two belt ends to form a juncture; second, applying an adhesive strip to the juncture; third, applying a compressing force to the adhesive strip; fourth, heating the adhesive strip for a heating period; fifth, cooling the adhesive strip for a cooling period; thus forming a puzzle-cut seam; and, sixth, determining when the puzzle-cut seam is satisfactory. When it is determined the puzzle-cut seam is not satisfactory, the heating and cooling steps are repeated. When it is determined the puzzle-cut seam is satisfactory, the compressing force is removed. In one embodiment, the method determines when the puzzle-cut seam is satisfactory based on the total time heat is applied to the adhesive strip.
U.S. Pat. No. 6,318,223 discloses another method and apparatus for producing an endless flexible seamed belt using templates. A first form of the template is a mask template with a template aperture in the form of a puzzle cut pattern to be used in combination with an excimer laser. The template is placed between the excimer laser source and the belt material to be cut. As the excimer laser traverses the width of the belt, the laser forms a puzzle cut pattern on the belt. A second form of the template is a punch and die having patterned edges in the form of a puzzle cut pattern with extremely small nodes and kerfs. The cutting tolerances of the patterned edges make it necessary to fix the punch with respect to the die so that there is no misalignment of the punch and die between cutting operations. This is accomplished by resiliently fixing the punch to the die, rather than having the punch attached to the force generating assembly as in normal punch and die assemblies. Belt material is positioned between a stock gap between the punch and die and the force generating assembly is activated to provide the cutting force. Once the belt material is cut, the cutting force is removed and the force generating assembly returns to its retracted position. Both types of templates result in very clean cuts without deformation or distortion.
U.S. Pat. No. 6,652,691 discloses a process for providing an improved imaging member belt having a welded seam that exhibits greater resistance to dynamic fatigue induced seam cracking and delamination. An apparatus for achieving stress relaxation and eliminating protrusions in the seam region is also disclosed.
Thus, there is a continuing need for a method of fabricating flexible imaging belts each having an improved seam design that is thin in seam profile, without splashing formation and seam protrusion spots, and thus has a smooth surface topology, is resistant to seam cracking/delamination, and has a seam region physical continuity free of factors that damage imaging machine subsystems.
In accordance with the present disclosure, there has been provided a method of fabricating an endless flexible belt having a circumference L1 and a thin seam profile. The method includes (a) cutting a work sheet of flexible belt material from a web of such material so that the work sheet has a first end and a first end region, a second end and a second end region, and a length L2 that is D units greater than L1; (b) looping the work sheet and overlapping the first end region and the second end region thereof by D units to form an overlapping dual end region; (c) making a single slice through the overlapping dual end region to produce a first, male side and a second, female side of the slice, and to produce a belt-length sheet, the first, male side of the slice comprising a first, male end of the belt-length sheet, and the second, female side of the slice comprising a second, female end of the belt-length sheet; (d) looping the belt-length sheet, re-aligning and mating the first, male side and the second, female side of the single slice to form a no-discrepancy abutment; and (e) heating and fusing the no-discrepancy abutment to form an endless flexible belt having a thin profile seam including no undesirable thickness variations and no undesirable protrusions.
In accordance with another aspect of the present disclosure, there is provided apparatus for fabricating, from a web of flexible belt material having an inner surface and an outer surface, an endless flexible belt having a circumference L1 and a thin profile seam. The apparatus includes (a) a slicing tool having (i) a razor-thin slicing edge for making a single slice through an overlapped dual end region of a worksheet length of the flexible belt material to create a belt-length sheet, (ii) a first side of the razor-thin edge that forms a first, male side of the single slice at a first end of the belt-length sheet, and (iii) a second side of the razor-thin edge that forms a second, female side of the single slice at a second end of the belt-length sheet; (b) supporting members for supporting the first, male side and the second, female side of the single slice at the first end and the second end of the belt-length sheet into a loop-forming, mating and no-discrepancy abutment; and (c) heaters for heating and fusing the no-discrepancy abutment to form an endless flexible belt having a thin profile seam including no undesirable thickness variations and no undesirable protrusions.
In the detailed description presented below, reference is made to the drawings, in which:
Referring first to
After the electrostatic latent image has been so developed, it is subsequently transferred to a copy sheet 16 by transfer means 15. After such transfer, the copy sheet 16 is advanced to fusing station 19, depicted in
A pointed out above, the quality of the image so formed, developed and transferred as described above depends in part on the morphological characteristics of the seam 50 (
Referring now to
Referring now to
Referring now to
The method of the present disclosure thus next includes making the single slice 70 from the first edge 35 to the second edge 36, with the single slice 70 having the first, male side 96 that may include puzzle-cut tabs, and the second, female side 98 that may include puzzle-cut mating edges as are well known in the prior art. The single slice 70 as such is made through the overlapping dual-end region 68 in order to produce the belt-length sheet 66 having the length L1. As made, the first, male side 96 comprises the first, male end 30 of the belt-length sheet 66, and eventually of the belt 10, and the second, female side 98 comprises second, female end 32 of the belt-length sheet 66 and hence of the belt 10. As further illustrated in
The single slice 70 is thus made simultaneously through the first-cut end 64 and the second-cut end 65 of the worksheet 62, thereby assuring perfectly re-mateable male and female sides 96, 98 in the discarded portions of the ends 64, 65, as well as in the resulting first, male end 30 and second, female end 32 of the belt-length sheet 66. The single slice or cut 70 can of course be of any suitable pattern producing male and female sides depending on the pattern shape of the tool 90, and as such includes non-puzzle cuts, as well as all types of puzzle-cuts as disclosed for example in U.S. Pat. No. 6,751,435, relevant portions of which are incorporated herein by reference.
Referring now to
Thus the method of the present disclosure further includes next looping the belt-length sheet 66 into a belt-length loop 66′ having the outer surface 33 out, re-aligning and mating end-to-end the first, male end 30, and the second, female end 32 of the belt-length sheet 66 to form the no-discrepancy abutment 49 as shown, and then heating and fusing the no-discrepancy abutment 49 to form the thin profile seam 50 and the endless flexible belt 10.
As shown in FIGS. 5 an 6, the apparatus 100 includes heating means 120 for heating and fusing the no-discrepancy abutment 49 in order to form the thin profile seam 50 and the endless flexible belt 10. The heating means 120 may include a first heating device 122 for heating the outer surface 33 of the belt-length loop 66′ around the no-discrepancy abutment 49. The first heating device 122 may also include a relatively greater intensity heating portion 124 located directly over the no-discrepancy abutment 49 for heating the no-discrepancy abutment more intensely than other areas surrounding such abutment 49. The heating means 120 also include a second heating device 126 for heating the inner surface 34 of the belt-length loop 66′ around the no-discrepancy abutment 49.
The apparatus 100 also includes compressing means 130 for compressing and flowing belt-length loop material around the no-discrepancy abutment 49 into the no-discrepancy abutment 49. The compressing means 130 for example comprise at least one rotatable roller 132, 134 that is rotatable reversibly along a longitudinal axis Ax of the belt-length loop 66′. In one embodiment, the compressing means comprise a pair of rotatable rollers 132, 134 that are each rotatable reversibly as shown along the longitudinal axis Ax of the belt-length loop 66′. The purpose of the roller or rollers 132, 134, is for compressing and flowing belt-length lop material around the no-discrepancy abutment 49 only in a first direction along the longitudinal axis Ax of the belt-length loop 66′, and into the no-discrepancy abutment 49.
According to one aspect of the method of the present disclosure, with the clamps 116, 118 in operation, and with the heating means 120 fully operational, first one compression roller, for example roller 132, is first rotated clockwise from a first position away from the abutment 49 towards and past the abutment 49 into a second position therefor. That same compression roller 132 is then reversibly rotated counter-clockwise from such second position beyond the abutment 49 back across the abutment 49 to the initial position to the left of the abutment 49 as shown. This has the desired effect of causing heated belt-length loop material in the heated region around the abutment 49 to flow in the direction of movement of such compression roller. In the embodiment having a pair of such compression rollers 132, 134, the movement of the first roller 132 is replicated appositely with the appositely located compression roller 134.
According to one more aspect of the present disclosure, the apparatus 100 includes edge guides 140, 142 for preventing compressed belt-length loop material from flowing in a second, cross-axial direction beyond the normal position of the first edge 35 and the second edge 36 of the belt-length loop 66′. As illustrated, the region of the loop 66′ around the abutment 49 is recessed within the guides 140, 142 so that the width and thickness of the belt 10 around the finished seam 50 are not adversely affected by cross-axial flow of material beyond either of a first edge and a second edge of the belt-length loop. The resulting thin profile seam 50 as formed includes no undesirable thickness variations and no undesirable protrusions. As a consequence, the resulting seamed flexible belt 10 functions essentially like a seamless belt and meets stringent imaging requirements.
A number of examples are set forth hereinbelow and are illustrative of different compositions and conditions that can be utilized in practicing the seam designs disclosed herein. All proportions are by weight unless otherwise indicated. It will be apparent, however, that the development can be practiced with many types of compositions and can have many different uses in accordance with the disclosure above and as pointed out hereinafter.
Imaging Member Preparation Example
A flexible electrophotographic imaging member web stock was prepared by providing a roll of titanium coated biaxially oriented thermoplastic polyester (PET, Melinex, available from ICI Americas Inc.) substrate having a thickness of 3 mils (76.2 micrometers). Applied thereto, using a gravure applicator, was a solution containing 50 parts by weight of 3-aminopropyltriethoxysilane, 50.2 parts by weight of distilled water, 15 parts by weight of acetic acid, 684.8 parts by weight of 200 proof denatured alcohol, and 200 parts by weight of heptane. This layer was then dried to a maximum temperature of 290° F. (143.3° C.) in a forced air oven. The resulting blocking layer had a dry thickness of 0.05 micrometer.
An adhesive interface layer was then prepared by applying to the blocking layer a wet coating containing 5 percent by weight, based on the total weight of the solution, of polyester adhesive (Mor-Ester 49,000, available from Morton International, Inc.) in a 70:30 volume ratio mixture of tetrahydrofuran/cyclohexanone. The adhesive interface layer was dried to a maximum temperature of 275° F. (135° C.) in a forced air oven. The resulting adhesive interface layer had a dry thickness of 0.07 micrometers.
The adhesive interface layer was thereafter coated with a photogenerating layer containing 7.5 percent by volume of trigonal selenium, 25 percent by volume of N,N′-dipheny-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine, and 67.5 percent by volume of polyvinylcarbazole. This photogenerating layer was prepared by introducing 160 gms of polyvinylcarbazole and 2,800 mis of a 1:1 volume ratio of a mixture of tetrahydrofuran and toluene into a 400 oz. amber bottle. To this solution was added 160 gms of trigonal selenium and 20,000 gms of ⅛ inch (3.2 millimeters) diameter stainless steel shot. This mixture was then placed on a ball mill for 72 to 96 hours. Subsequently, 500 gms of the resulting slurry were added to a solution of 36 gms of polyvinylcarbazole and 20 gms of N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine dissolved in 750 mis of 1:1 volume ratio of tetrahydrofuran/toluene. This slurry was then placed on a shaker for 10 minutes. The resulting slurry was thereafter applied to the adhesive interface by extrusion coating to form a layer having a wet thickness of 0.5 mil (12.7 micrometers). However, a strip about 3 mm wide along one edge of the coating web, having the blocking layer and adhesive layer, was deliberately left uncoated by any of the photogenerating layer material to facilitate adequate electrical contact with the ground strip layer that is applied later. This photogenerating layer was dried to a maximum temperature of 280° F. (138° C.) in a forced air oven to form a dry thickness photogenerating layer having a thickness of 2.0 micrometers.
This coated imaging member web was simultaneously coated over with a charge transport layer and a ground strip layer by co-extrusion of the coating materials. The charge transport layer was prepared by introducing into an amber glass bottle in a weight ratio of 1:1 (or 50% wt of each) of N,N′-diphenyl-N,N′-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine and Makrolon 5705, a Bisphenol A polycarbonate thermoplastic having a molecular weight of about 120,000 commercially available from Farbensabricken Bayer A.G. The resulting mixture was dissolved to give 15 percent by weight solid in methylene chloride. This solution was applied on the photogenerator layer by extrusion to form a coating, which upon drying gave a thickness of 24 micrometers.
The strip, about 3 mm wide, of the adhesive layer left uncoated by the photogenerator layer, was coated with a ground strip layer during the co-extrusion process. The ground strip layer coating mixture was prepared by combining 23.81 gms. of polycarbonate resin (Makrolon 5705, 7.87 percent by total weight solids, available from Bayer A.G.), and 332 gms of methylene chloride in a carboy container. The container was covered tightly and placed on a roll mill for about 24 hours until the polycarbonate was dissolved in the methylene chloride. The resulting solution was mixed for 15-30 minutes with about 93.89 gms of graphite dispersion (12.3 percent by weight solids) of 9.41 parts by weight of graphite, 2.87 parts by weight of ethyl cellulose and 87.7 parts by weight of solvent (Acheson Graphite dispersion RW22790, available from Acheson Colloids Company) with the aid of a high shear blade dispersed in a water cooled, jacketed container to prevent the dispersion from overheating and losing solvent. The resulting dispersion was then filtered and the viscosity was adjusted with the aid of methylene chloride. This ground strip layer coating mixture was then applied, by co-extrusion with the charge transport layer, to the electrophotographic imaging member web to form an electrically conductive ground strip layer having a dried thickness of about 14 micrometers.
The resulting imaging member web containing all of the above layers was then passed through a maximum temperature zone of 257° F. (125° C.) in a forced air oven to simultaneously dry both the charge transport layer and the ground strip. The imaging member at this point, if unrestrained, will spontaneously curl upward, an anti-curl back coating is needed to render its desired flatness. An anti-curl coating was prepared by combining 88.2 gms of polycarbonate resin (Makrolon 5705, available from Goodyear Tire and Rubber Company) and 900.7 gms of methylene chloride in a carboy container to form a coating solution containing 8.9 percent solids. The container was covered tightly and placed on a roll mill for about 24 hours until the polycarbonate and polyester were dissolved in the methylene chloride. 4.5 gms of silane treated microcrystalline silica was dispersed in the resulting solution with a high shear dispersion to form the anti-curl coating solution. The anti-curl coating solution was then applied to the rear surface (side opposite the photogenerator layer and charge transport layer) of the electrophotographic imaging member web by extrusion coating and dried to a maximum temperature of 220° F. (104° C.) in a forced air oven to produce a dried coating layer having a thickness of 13.5 micrometers.
Prior Art Overlap Seam Preparation
The prepared flexible electrophotographic imaging member web stock of the Imaging Member Preparation Example above, having a width of 353 mm, was cut transversely to provide one rectangular sheet of precise 508 mm in length and having four vertically sides for flexible imaging member belt seaming preparation. The opposite ends of the first one of these imaging member cut sheets were brought together to give 1 mm overlap and then joined by ultrasonic energy seam welding process using a 40 Khz horn frequency to produce an electrophotographic imaging member belt having an ultrasonically welded prior art overlap seam control, which, according to that illustrated in
Thin Profile Prior Art Seam Preparation
The prepared electrophotographic imaging member web stock of the Imaging Member Preparation Example above, having a width of 353 mm, was cut through the cross web direction, with a puzzle cut die to give a rectangular sheet having a pair of opposite ends consisting of correspondingly complementing puzzle cut patterns. For imaging member belt preparation, the rectangular imaging member cut sheet was looped in order to bring the pair of opposite puzzle cut pattern ends together for mating and mechanical interlocking of the puzzle cut elements into a butt joint alignment having a 35 micrometers kerf or crevice and a 508 mm belt circumference.
The mated puzzle cut end pair of the looped imaging member sheet was then subjected to compression/heat processing step, held at 80 lbs/in2/200° C. for 6 seconds and then cooling for 15 seconds, to allow materials flow and fill the crevice for fusion bonding; therefore the compression/heat processing did effect direct imaging layers heat fusion of the puzzle cut mated elements into an imaging member belt having An abutted fusion bonded prior art seam.
Seam Preparation According to this Diclosure
The prepared flexible electrophotographic imaging member web stock of the Imaging Member Preparation Example above, having a width of 353 mm, was cut in any suitable manner through the cross web direction to give a rectangular sheet of 520 mm in length. The two opposite ends of the rectangular imaging member cut sheet were then brought together and overlapped forming a dual-end overlapping portion in accordance with the present disclosure, such as to give a circumferential belt dimension of 508 mm. With a shear puzzle cut die (cutting or slicing tool), a perfect male-female matching ends pair is created. The mal, female matching ends pair, having a perfectly fitted butt joint alignment without a crevice, was then subjected to compression/heat processing step, again held at 80 lbs/in2/200° C. for 6 seconds and then cooling for 15 seconds to effect fusion bonding result, by following the detailed descriptions presented in
Physical and Mechanical Evaluation
The three flexible imaging member belts comprising the Prior Art Overlap seam, the Thin profile Prior Art Seam, and the thin profile disclosure seam 50 described above were analyzed for respective seam surface topology using a surface analyzer, Surftest 402, available from Mitutoyo Company. The surface profile obtained for the ultrasonically welded control prior art seam, as that shown in
When evaluated for tensile seam rupture strength using an Instron Mechanical Tester, the ultrasonic welded overlap seam had a seam rupture strength about 54.2 lbs/in., slightly higher than the 52.3 lbs/in obtained disclosure fusion bonded seam counterpart; however, this small differences in strength is of practical in significant because it is still much greater than the rupture strength of 35 lbs/in. seam SPEC for flexible belt.
By sharp contrast, the thin profile fusion bonded prior art seam (formed from a 30 micrometers crevice joint) had given a seam rupture strength of only 15.6 lbs/in. This is too low a seam strength value to warrant mechanical seam integrity of belt life during dynamic imaging member belt machine function in the field.
Dynamic Imaging Belt Cycling
Two of the prepared flexible electrophotographic imaging member belts described above (one having the ultrasonically welded prior art overlap seam control and the other a fusion bonded seam of this disclosure) were each dynamically cycled tested, to the point of onset of seam failure, in a xerographic machine utilizing a belt support module comprising a 25.24 mm diameter drive roller, a 25.24 mm diameter stripper roller, and a 29.48 mm diameter tension roller to exert to each belt a tension of 1.1 pounds per inch. The belt cycling speed was set at 65 prints per minute.
The control imaging member belt, was cyclic tested to produce an equivalent of only about 56,000 print copies and terminated for the reason of onset of seam cracking/delamination. During dynamic belt cycling process, a slight belt motion speed disturbance was registered each time the seam of the belt was transported passing over a belt support module roller, because the seam splashing coupled with the added differential seam region thickness did essentially behave as a speed bump to impact the belt motion quality.
With the very same machine, belt cycling procedures were repeated for the disclosure seamed belt. Neither seam failure nor cleaning blade wear problem were observed after completion of approximately 750,000 equivalent print copies of belt cyclic testing. It is important to further point out that, unlike the ultrasonically welded prior art seamed belt control counterpart, no undesirable dynamic belt motion quality impact was not notable, since the imaging member belt, prepared to have a butt-joint invention fusion bonded seam, having smooth top and bottom topology, excellent physical continuity, and no thickness variance, did function virtually like a seamless belt.
Consequently, the thin profile, fusion bonded seam design disclosed herein reduces seam cracking/delamination problems, having no seam splash junction physical discontinuity, provides smoother surface topology of no added seam region thickness, excellent physical continuity, improved belt motion quality, cleaning blade wear suppression, good seam rupture strength, and very importantly, a prepared seamed belt is substantially free of high protrusion spots in the seam to thereby reduce imaging member belt rejection rates to increase imaging member belt production yield as well. Furthermore, the seam quality is improved utilizing the seam design of this disclosure such that the manual seam inspection steps may, in some instances, be eliminated.
Although it can be rationalized that the fusion bonding of the puzzle cut pattern should give stronger seam rupture strength than that if the bonded fusion seam was formed from a pair of straight cut ends, because the puzzle cut ends had a much longer bonding line than that of the straight cut ends, however, the present disclosure concept does extend to include fusion bonded seamed belts having a seam formed from mating/fusing straight cut ends.
The above comparative results are illustrated in
As can be seen, there has been provided a method of fabricating, from a web of flexible belt material having an inner surface and an outer surface, an endless flexible belt having a circumference L1 and a thin profile seam. The method includes (a) cutting a work sheet of the flexible belt material from the web of flexible belt material, the work sheet having a first edge and a second edge, a first end, a first end region, a second end, a second end region, and a length L2 being D units greater than L1; (b) first looping the work sheet, outer surface out, and overlapping the first end region and the second end region thereof by D units to form an overlapping dual end region; (c) making a single slice from the first edge to the second edge, the single slice having a first, male side and a second, female side through the overlapping dual end region to produce a belt-length sheet having a length L1, the first male side comprising a first, male end of the belt-length sheet, and the second, female side comprising a second, female end of the belt-length sheet; (d) next looping the belt-length sheet into a belt-length loop having outer surface out, re-aligning and mating end-to-end the first, male end and the second, female end of the belt-length sheet to form a no-discrepancy abutment of the first, male end and the second, female end; and (e) heating and fusing the no-discrepancy abutment to form an endless flexible belt having the first edge, the second edge, and a thin profile seam including no undesirable thickness variations and no undesirable protrusions.
While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are or may be presently unforeseen may arise to applicants or others skilled in the art. Accordingly, the appended claims as filed and as they may be amended are intended to embrace all such alternatives, modifications variations, improvements, and substantial equivalents.
This application claims the benefit of Provisional Patent Application No. 60/623,707 filed Oct. 29, 2004.
| Number | Date | Country | |
|---|---|---|---|
| 60623707 | Oct 2004 | US |
