JP4478825B2 - Tube roll manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  This invention isLeMore specifically, the manufacturing method achieves high surface smoothness and uniform nip pressure (nip amount), and is used for electric latent image printing such as electrophotographic systems such as copying machines and electrostatic recording systems. Tuberows suitable for use in so-called secondary transfer rolls, etc.LeIt relates to a method of manufacturing.
[0002]
[Prior art]
For transfer rolls used in copiers, fax machines and other office equipment, etc., good surface smoothness and good variation with little variation due to good parts for good transport of printing media such as paper to be transported Nip pressure is required. And as a suitable manufacturing method of the tube roll 60 which has such a physical property, the method as shown in FIG. 8 is mentioned.
[0003]
That is, the outer diameter core 72 capable of forming the insertion hole 64a to the extent that the shaft 68 of the roll can be press-fitted into the molding die 70 having the inner contour shape that matches the outer contour shape of the tube roll 60 to be obtained. By setting and injecting the polyurethane foam raw material, a cylindrical polyurethane foam 64 whose outer diameter is approximately the same as the roll to be obtained is obtained (see FIG. 8A). Then, a polishing rotation shaft 74 is press-fitted into the central axis of the obtained cylindrical polyurethane foam 64 so as to adjust the outer diameter of the foam 64 (see FIG. 8B).
[0004]
Next, the polishing rotation shaft 74 is removed from the cylindrical polyurethane foam 64 whose polishing process is completed and the outer diameter is adjusted, and a product shaft 68 is press-fitted instead (FIG. 8 (c)). reference). At this time, an adhesive component such as an adhesive may be applied to the outer peripheral surface of the shaft 68 as necessary. Finally, a predetermined amount of an adhesive component such as an adhesive is applied to the outer peripheral surface of the cylindrical polyurethane foam 64 that has been polished, and the tube roll 60 in which the foam 64 in this state is to be obtained in a separate process in advance. The tube roll 60 is obtained by interpolating and laminating the cylindrical outer tube 62 manufactured in accordance with the outer diameter of the tube (see FIG. 8D).
[0005]
  In addition, a roll having a structure such as the tube roll 60 can be manufactured by a general coating method. In the case of the coating method, when a good surface layer is formed on an elastic body such as urethane foam, there is no void on the surface of the elastic body as a base, and the elastic body is swollen by the solvent of the coating solution. It is necessary to prevent deformation such as a change in outer diameter. Therefore, a solid (non-foamed body) is used as the elastic body, a so-called skin structure porous body having no bubbles on the surface, or bubbles existing on the surface are observed with a solventless liquid elastomer or the like. There has been a need to use a porous body with a stop. In this case, compared with the case where the porous body is used as it is, the hardness becomes higher, and the following problems have occurred. That is,
(1)As the hardness of the roller increases, the nip pressure of the roller with respect to the photosensitive drum and image recording paper decreases, and in severe cases, a local gap is generated between the paper and the roller, which is necessary for development and transfer. The electrical action that is performed cannot be performed.
(2)Above(1)In order to prevent the occurrence of defects, the roller contacts the photosensitive drum or image recording paper.PowerIf the photosensitive drum or toner isPowerIs added, and the progress of deterioration of the drum or the roller itself is accelerated, or the roller is permanently set. As a result, a problem is pointed out that the nip pressure becomes unstable or a local non-contact state occurs.
[0006]
[Problems to be solved by the invention]
In the manufacturing process described above, high surface smoothness and good nip pressure are achieved by laminating the two members of the outer tube 62 and the polyurethane foam 64. As is apparent from the manufacturing process described above, the outer diameter of the tube roll 60 is obtained by polishing the cylindrical outer tube 62 manufactured in a separate process so as to match the outer diameter of the roll 60. Is produced by interpolating the polyurethane foam 64 with the shape adjusted, and the process is complicated, and the degree of the interpolation greatly affects the surface smoothness and the nip pressure expressed by the tube roll 60. Is pointed out.
[0007]
That is, the higher the dimensional accuracy of the outer tube 62 and the polyurethane foam 64, the better the state after the tube 62 and the foam 64 are laminated, but the more difficult the interpolation of the foam 64 with respect to the tube 62 becomes. On the other hand, if the outer diameter of the polyurethane foam 64 is smaller than the inner diameter of the outer tube 62, the foam 64 can be easily inserted into the tube 62, but the tube 62 and the foam 64 are laminated in a good state. In other words, it has become a basis for serious defects such as variations in nip pressure due to the portion of the tube roll 60 to be obtained.
[0008]
Further, in the actual use of the tube roll 60, the bonding strength in the lamination of the outer tube 62 and the polyurethane foam 64, specifically, the applied amount of the adhesive component interposed between the tube 62 and the foam 64 and uniform dispersion. The properties also have a great influence on the development of high surface smoothness and good nip pressure. However, as is apparent from the manufacturing process described above, when the inner diameter of the outer tube 62 and the outer diameter of the polyurethane foam 64 are matched, the adhesive component applied to the outer peripheral surface of the foam 64 is As the foam 64 is likely to peel off from the outer peripheral surface when the foam 64 is inserted into the tube 62, the adhesive strength varies depending on the portion of the tube roll 60 to be obtained. As a result, the above-described nip pressure or the like is deteriorated. There are inherent problems. On the other hand, when the outer diameter of the polyurethane foam 64 is set to be smaller than the inner diameter of the outer tube 62, it is difficult to uniformly apply an adhesive component to the outer peripheral surface. The same problem is pointed out that the fluctuation of the adhesive strength due to.
[0009]
Furthermore, not only the problem of the adhesive strength, but also the case where the inner diameter of the outer tube 62 and the outer diameter of the polyurethane foam 64 are matched and the outer diameter of the polyurethane foam 64 is set smaller than the inner diameter of the outer tube 62. In any case, the outer surface of the tube roll 60 to be obtained is configured due to the difficulty of performing the interpolation in a state where it is physically impossible and the difficulty of applying the adhesive component uniformly. The outer tube 62 is in a so-called wavy state, and the surface smoothness is also impaired.
[0010]
In addition, the outer tube 62 is basically processed from a raw material into a tube shape by extrusion molding. However, in this processing, the above-described wavy state occurs due to expansion and contraction of the material, thereby improving yield and the like. Was hindered. In order to avoid this wavy state, generally, (1) the hardness of the polyurethane foam 64 is made high, and (2) the outer tube 62 is made thicker or a high hardness substance is used to withstand the extrusion process. A method of improving the deformability has been adopted.
[0011]
However, the following problems are pointed out in the above-described methods. That is,
(1) The hardness of the polyurethane foam 64, which is a main component of the tube roll 60 to be obtained and forms the base material, has a great influence on the nip pressure of the tube roll 60 as it is, and the nip increases with the increase in the hardness. The pressure becomes small, and a good nip pressure at a low load cannot be obtained.
{Circle around (2)} When the outer tube 62 is made thicker, the nip pressure of the obtained tube roll 60 becomes small as in the above {circle around (1)}. Furthermore, since the degree of influence on the roundness, which is one of the important geometric indices of the tube roll 60 to be obtained, increases, an advanced extrusion molding apparatus that can precisely control the roundness of the outer tube 62 itself. And a method are required, and as a result, the manufacturing cost increases.
[0012]
Further, depending on the intended use of the tube roll 60, the outer tube 62 may be mixed with a conductive material, or the tube 62 may be manufactured from a conductive material itself such as a metal thin film. The roll which can be used suitably also for the required roll use can be manufactured. However, due to the above-described phenomenon occurring between the outer tube 62 and the polyurethane foam 64, the conductivity may vary greatly depending on the portion. As a result, the tube roll 60 having good conductivity can be obtained. It was difficult to get.
[0013]
OBJECT OF THE INVENTION
  In view of the problems inherent in the tube roll obtained by the mechanical floss method and the manufacturing method thereof according to the prior art, the present invention has been proposed to suitably solve the problem, and the manufacturing process is simplified. In addition, the resulting tube roll can exhibit both high surface smoothness and good nip pressure.LeAn object is to provide a manufacturing method.
[0016]
[Means for Solving the Problems]
  In order to overcome the above-mentioned problems and achieve the intended purpose, a method for producing a tube roll according to the present invention comprises:
  Outer diameter matched to the outer diameter of the tube rollAnd both ends openPrepare an external tube and connect both ends of the external tubeTo blockWhile installing the fixed mold, align the central axis with the outer tube, and insert the shaft,
  Blocked by the fixed moldIn the annular space defined between the outer tube and the shaft,Through the raw material injection hole provided in one fixed mold facing the annular space.Injected polyurethane foam material that has been air-loaded in advanceAnd exhausting the air in the annular space through a discharge hole provided facing the annular space on the other fixed mold,
  By filling and curing the polyurethane foam raw material, the annular space is filled with polyurethane foam,
  Then, each of the outer tube and the shaftBeforeThe tube roll bonded to the foamed / cured polyurethane foam,It is configured to be removed from the fixed mold.
[0017]
  In order to overcome the above-mentioned problems and achieve the intended purpose,
  On the inner peripheral surface of a roll mold having an inner contour shape that matches the outer contour shape of the tube roll, Both ends openInstall the outer tube, align the central axis with the outer tube, and insert the shaft.
  Roll forming moldThe outer tube whose both end faces are closed withInsideInshaftWhenIn the annular space defined betweenVia the raw material injection hole provided in the roll mold so as to face one end face of the outer tubeInjected polyurethane foam material that has been air-loaded in advanceAnd exhausting the air in the annular space through the discharge hole provided in the roll mold facing the other end surface of the outer tube,
  By filling and curing the polyurethane foam raw material, the annular space is filled with polyurethane foam,
  Then, each of the outer tube and the shaftBeforeThe tube roll bonded to the foamed / cured polyurethane foam,It is characterized by being taken out from the roll mold.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
  Next, a tube flow according to a preferred embodiment of the present invention.LeAbout a manufacturing method, a suitable Example is given and demonstrated below. The inventor of the present application injects a polyurethane foam raw material at a predetermined flow rate between an outer tube matched with the outer diameter of a tube roll to be obtained and a shaft arranged with the central axis aligned with the outer tube, It has been found that by foaming and curing this to form a polyurethane foam, each of the outer tube and the shaft can be firmly joined to the polyurethane foam.
[0019]
As shown in FIG. 1, the tube roll 10 according to a preferred embodiment of the present invention is set to a material and thickness that can ensure the surface smoothness and nip pressure required by the tube roll 10 to be basically obtained. The outer tube 12 is aligned with the central axis of the outer tube 12 and the shaft 18 serving as the rotation axis of the tube roll 10 and the annular space 16 defined between the outer tube 12 and the shaft 18 are provided. The polyurethane foam 14 is formed by foaming and curing a predetermined polyurethane foam raw material M to be injected. Here, the outer tube 12 and the shaft 18 are physically and firmly joined by the foamed / cured polyurethane foam 14.
[0020]
Next, the manufacturing mechanism 20 provided with the roll forming die 30 for suitably manufacturing the tube roll 10 according to the present embodiment, and the manufacturing method using the manufacturing mechanism 20 will be described below. It is assumed that the polyurethane foam raw material M, the external tube 12 and the shaft 18 which are raw materials of the polyurethane foam 14 forming the base material of the tube roll 10 are prepared.
[0021]
As shown in FIGS. 2 and 5, the manufacturing process of the tube roll 10 includes a raw material preparation step S1, a member installation step S2, a polyurethane foam raw material injection step S3, a curing / demolding step S4, and a final step S5. 3 is suitably manufactured by the manufacturing mechanism 20 including the roll forming die 30 shown in FIG. The roll mold 30 basically performs the above-described member installation step S2, the polyurethane foam raw material injection step S3, and the curing / demolding step S4 continuously. About the raw material preparation step S1 and the final step S5 Is performed by another apparatus in the manufacturing mechanism 20.
[0022]
(Outline of roll forming mold and manufacturing mechanism)
As shown in FIG. 4, the roll forming die 30 is a main part of the manufacturing mechanism 20 for manufacturing the tube roll 10, and includes a pair of roll forming split molds 32 and 32 configured to be freely opened and closed. Then, the roll forming split mold 32 is formed by recessing the forming cavity halves 32a and 32a of the tube roll 10 to be obtained on the inner side thereof, so that the shaft 18 is installed and the mold is closed (closed). Further, an annular space 16 is formed as a cavity having an inner peripheral surface 34 that defines the outer contour shape of the tube roll. Further, the manufacturing mechanism 20 includes a discharge mechanism that includes a discharge nozzle 22 that moves detachably with respect to a raw material injection hole 36 (to be described later [0024]) in the roll mold 30 and discharges the polyurethane foam raw material M. 24 and a storage and mixing mechanism 26 for storing the polyurethane foam raw material M supplied to the discharge mechanism 24 under a predetermined pressure (see FIG. 3). The dividing line formed between the contact surfaces 32b and 32b that contact each other when the pair of roll forming split molds 32 and 32 are closed is generally referred to as a parting line P. Will be used.
[0023]
A shaft disposed on the contact surfaces 32b at both ends in the longitudinal direction of the roll forming split mold 32 so as to be aligned with the central axis of the outer tube 12 (see [0030]) disposed on the inner peripheral surface 34. A through-groove 32c for positioning the shaft 18 is provided, and a through-hole 35 in which the shaft 18 is positioned is formed by closing the pair of roll forming split dies 32, 32. Further, a raw material injection hole 36 for injecting the polyurethane foam raw material M into the annular space 16 is provided at one end in the longitudinal direction of the roll forming split mold 32, and the other end is annular by injection of the polyurethane foam raw material M. A plurality of discharge holes 38 for air or the like pushed out from the space 16 are formed.
[0024]
Regarding the shape of the raw material injection hole 36, the outside where the polyurethane foam raw material M is injected is small, and the annular space 16 side is large, that is, processed into a taper shape. By this taper processing, after the tube roll 10 obtained by injecting and curing the polyurethane foam raw material M from the raw material injection hole 36 is released, the roll forming part on the side where the raw material waste remaining in the roll forming die 30 is opened is removed. It can be easily removed from the inside of the mold 32. The size of the discharge hole 38 is such that a polyurethane foam raw material M, which will be described later ([0035]), can be injected without causing pressure loss, specifically 5 mm.²It is set to a degree.
[0025]
(About raw material preparation process S1)
The raw material preparation step S <b> 1 is a step of preparing a polyurethane foam raw material M to be injected into the annular space 16 defined between the outer tube 12 and the shaft 18 constituting the tube roll 10. The polyurethane foam raw material M is manufactured by mixing the polyol component and isocyanate component, which are main raw materials, with the foaming agent, catalyst and other auxiliary raw materials in the storage and mixing mechanism 26 (see FIG. 5A). And the said polyurethane foam 14 obtained from this polyurethane foam raw material M is a foam body obtained by a general chemical foaming method, and is a member which makes the base material of the tube roll 10 which should be obtained.
[0026]
The storage and mixing mechanism 26 will be described in detail. A first storage tank 27 provided with an air loading device 27b that basically stores at least a polyol component, which will be described later ([0027]), and dissolves a predetermined amount of air under pressure; A second storage tank 28 for storing, for example, an isocyanate component other than the components stored in the first storage tank 27, and each raw material quantified and supplied under control from the storage tanks 27, 28 are pressurized. And a mixing and storage tank 29 for obtaining a polyurethane foam raw material M by stirring and mixing. Each of the tanks 27, 28, 29 is provided with required stirring means 27a, 28a, 29a as required. The details of air loading will be described later ([0039]).
[0027]
The polyol component used as a raw material here is a compound having two or more hydroxyl groups generally called a polyol, such as a polyether polyol, polyester polyol, polycarbonate polyol, polycaprolactone polyol, ethylene glycol or glycerin. Alternatively, mixed materials are preferred. In addition, a compound having an active hydrogen such as a carboxylic acid or an amine can be used in place of the hydroxyl group. Examples of the isocyanate component include tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate. The use of diphenylmethane diisocyanate (MDI) is particularly preferred from the viewpoint of production cost.
[0028]
  Examples of the auxiliary materials include a catalyst as a polymerization initiator used in the production of ordinary polyurethane foam, a crosslinking agent and a foaming agent, and a chain extender, a flame retardant or an ultraviolet absorber, an antioxidant, and an aging as necessary. Examples thereof include an inhibitor, a filler, a plasticizer, a colorant, an antifungal agent, and an antibacterial agent, and these auxiliary materials are added as necessary. Examples of the catalyst include conventionally known organotin catalysts, organic amine catalysts, organonickel catalysts, organoiron catalysts, and mixtures thereof. Particularly, the polyurethane foam raw material injected into the roll mold 30 A room-temperature reaction type catalyst such as triethylenediamine, which is an organic amine catalyst, is preferably used so that M foams and cures in a short time..
[0029]
Examples of the crosslinking agent include conventionally known polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, glycerin, trimethylolpropane, pentaerythritol, and sorbitol, and amines such as hexamethylenediamine, hydrazine, diethyltoluenediamine, and diethylenetriamine. And amino alcohols such as monoethanolamine, diethanolamine, and triethanolamine. Examples of the blowing agent include water, halogenated hydrocarbons such as HCFC-141b, HFC-116a, HFC-305fa or HFC-365mfc, hydrocarbons such as cyclopentane, isopentane, and normal pentane, nonafluorobutyl methyl ether, nona Hydrofluorocarbons such as fluoroisobutyl methyl ether, nonafluorobutyl ethyl ether, nonafluoroisobutyl ethyl ether, pentafluoroethyl methyl ether or heptafluoroisopropyl methyl ether, or liquefied carbon dioxide gas are used. Of these foaming agents, water is most preferable in terms of versatility. About the said foam stabilizer, the substance normally used by manufacture of a normal foam can be used. Examples thereof include various foam stabilizers such as dimethylsiloxane, polyether dimethylsiloxane, and phenylmethylsiloxane. Examples of the chain extender include polyvalent amines such as diethyltoluenediamine and dimethylthiotoluenediamine, and examples of the flame retardant include tris-dichloropropyl phosphate, tris-chloroethyl phosphate, dibromoneopentyl alcohol, and tribromo. Neopentyl alcohol and the like are 2- (2-hydroxy-5-tertiarybutylphenyl) benzotriazole, 2 ′-(2′hydroxy-3 ′, 5′-ditertiarybutylphenyl) 5 as the ultraviolet absorber. Examples thereof include chlorobenzotriazole, bis (2,2,6,6-tetramethyl-4-piperidine) separate, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine and the like.
[0030]
(About member installation process S2)
  The member installation step S <b> 2 is a step of installing the outer tube 12 and the shaft 18 at a required position in the roll mold 30. Specifically, the outer tube 12 is installed on the inner peripheral surface 34 of the closed roll forming die 30, and the shaft 18 has through holes 35 provided at both ends in the longitudinal direction of the roll forming die 30. , 35 (see FIG. 5B). At the end of this step S2, the roll mold 30 is prepared for a polyurethane foam raw material injection step S3 to be described later ([0034]).TypeIt is tightened. The roll mold 30 is preheated to a temperature (for example, about 40 ° C.) that can be withstood by the previously installed external tube 12 in order to quickly complete foaming and curing of the polyurethane foam raw material M. Also good.
[0031]
The outer tube 12 used in the member installation step S2 covers the outer peripheral surface of the polyurethane foam 14 that forms the base material in the obtained tube roll 10, and achieves high surface smoothness that cannot be achieved with the foam 14. It is a member to do. Specifically, various plastic materials that can be extruded are used, and preferably withstand the pressure from the polyurethane foam 14 when the annular space 16 inside the outer tube 12 is filled with the polyurethane foam 14. For example, a polyester resin such as polyethylene terephthalate (PET) that has sufficient mechanical strength and is inexpensive and is preferably used. In addition, thermoplastic resins such as olefin resin, nylon resin, polyethylene resin, polystyrene resin, polyimide or polyamide, or various thermosetting resins are preferably used.
[0032]
The thickness of the outer tube 12 is the surface smoothness required for the tube roll 10 to be obtained, the durability against the pressure accompanying the volume change due to the foaming / curing of the polyurethane foam raw material M to the annular space 16 described above, etc. In view of the above, and in consideration of suitable manufacturability of the outer tube 12 by extrusion molding, it is set to at least about 20 μm, preferably at least 50 μm. When this thickness is less than about 20 μm, it becomes difficult to extrude the outer tube 12 and problems such as failure to obtain a good tube roll 10 occur. In addition to this, it is finely set by the forming dies 30, 40 (described later in [0045]) or the fixed die 50 (described later in [0048]) used in the manufacture of the tube roll 10, and is used in this embodiment. In the case of the roll forming mold 30 that closes the plurality of roll forming split molds 32, 32, the outer tube 12 having a thickness of about 150 to 200 μm is used depending on the strength of the material. Is done. Regarding the thickness, the outer tube 12 having a thickness of less than 150 μm can be used, but the roll mold 30 is basically composed of a plurality of roll mold split molds 32, 32. The parting line P, which is the boundary between the split molds 32, 32, that is, the dividing line formed between the respective contact surfaces 32b, 32b, is caused by volume expansion due to foaming of the polyurethane foam raw material M in the curing / demolding step S4 described later. A problem arises in the surface smoothness of the tube roll 10 obtained by being transferred to the external tube 12. Depending on the intended use of the tube roll 10 to be used, a metal material obtained by mixing a predetermined conductive substance in each of the aforementioned raw materials or forming a thin film into a tube shape may be employed.
[0033]
Similarly, the shaft 18 used in this member installation step S2 fulfills various requirements such as mechanical strength, heat resistance and durability as a rotating shaft in an environment where the tube roll 10 which is a finished product is used. Conventionally known materials and structures can be used as long as they can be obtained. Further, in the manufacturing method according to the present invention, the thickness in the radial direction of the polyurethane foam 14 can be set in a range of about 1 to 10 mm (described later [0036]), so that the diameter is about 6 mm in order to make use of the thickness. Since the diameter of the tube roll 10 from which the smaller one is obtained can be made smaller, it is preferable.
[0034]
(About polyurethane foam material injection process S3)
The polyurethane foam raw material injection step S3 is defined by the outer tube 12 and the shaft 18 in the roll forming die 30 in which the outer tube 12 and the shaft 18 are installed and closed and clamped. This is a step of injecting a required amount of polyurethane foam raw material M into the annular space 16 at a required injection flow rate. The polyurethane foam raw material M is injected from the storage and mixing mechanism 26 into the annular space 16 through the discharge mechanism 24, the discharge nozzle 22, and the raw material injection hole 36 (see FIG. 5C). At that time, the air filling the annular space 16 is discharged from the discharge hole 38 formed on the facing surface of the raw material injection hole 36 in the roll mold 30 due to the volume expansion accompanying the foaming of the polyurethane foam raw material M. It is discharged sequentially.
[0035]
The amount of the polyurethane foam raw material M injected in the present polyurethane foam raw material injection step S3 is foamed and cured as it is in the shape of the annular space 16, so the size (total volume) of the tube roll 10 to be obtained, specifically, Determined by diameter and the like. In particular, the diameter of the tube roll 10 has a strong tendency to shrink with the recent miniaturization of copying machines and the like, and the annular space 16 should be obtained in order to secure a good nip pressure intended by the present invention. The width of the tube roll 10 (polyurethane foam 14) in the radial direction (hereinafter referred to as width), that is, the injection clearance is set in the range of 1 to 10 mm, preferably 5 to 10 mm, and the density of the obtained polyurethane foam 14 is 0.15-0.5 g / cm^ThreeIt is preferable to set in the range. Therefore, the amount of the polyurethane foam raw material M to be injected is a numerical value obtained by multiplying the volume of the polyurethane foam 14 obtained by foaming / curing by the above density. Specifically, if the length of the tube roll 10 that is preferably used is 32 cm, the diameter is 2 cm, and the diameter of the shaft 18 is 0.8 cm, the total volume of the polyurethane foam 14 is 84 cm.^ThreeTherefore, (1) is calculated to be about 12.6 to 42 g. Actually, since the inside of the annular space 16 needs to be completely filled with the polyurethane foam raw material M, the raw material M is excessively injected, and an excess portion is supplied from the discharge hole 38 to the outside of the roll mold 30. This step S3 is performed so as to be discharged. As for the size of the discharge hole 38, the polyurethane foam raw material M must be injected into the annular space 16 from the raw material injection hole 36 without causing pressure loss.
[0036]
And in order to make the width | variety of the annular space 16 mentioned above into 5-10 mm, it is necessary to make the diameter of the said raw material injection hole 36 into the range of 1-5 mm (in the case of 1-5 mm in width, it is below this width and Become). In order to satisfactorily inject the polyurethane foam raw material M from the raw material injection hole 36 having such a small diameter, it is necessary to suppress the pressure loss applied at the time of the injection, here the conditions at the time of the injection. As an effective method for suppressing this pressure loss, the injection flow rate can be reduced, that is, the injection flow rate can be reduced. In view of this point, in the present invention, the injection flow rate into the annular space 16 is set in the range of 0.3 to 10 g / min. If the injection flow rate is less than 0.3 g / min, the capacity range of the small amount discharge in the existing apparatus is out of the range. It becomes large and the injection cannot be carried out suitably, and as a result, it becomes difficult to produce the polyurethane foam 14 having a homogeneous cell structure.
[0037]
In addition, the polyurethane foam raw material M is required to be uniformly injected into the annular space 16 so that the polyurethane foam 14 obtained from the raw material M can ensure a good nip pressure or the like. Specifically, it is injected from the raw material injection hole 36 having a very small diameter, and has a viscosity that exhibits appropriate fluidity so that it can be sufficiently distributed throughout the narrow annular space 16 and sufficiently foamed. .15 to 0.5 g / cm^ThreeBoth the density and the density set in the range are required. In order to achieve both of these requirements suitably, in the present invention, the polyurethane foam raw material M is air-loaded, that is, achieved by dissolving a predetermined amount of a foaming source gas under pressure. is doing.
[0038]
As described above, the air loading refers to a process for forcibly dissolving a predetermined amount of various gases that can become cells of the polyurethane foam 14 into a liquid raw material such as a polyol component under pressure. Here, the various gases dissolved in the polyol component become the polyurethane foam raw material M in which the gas is dissolved by being mixed with other raw materials. And the dissolution of the gas expresses the effect of decreasing the viscosity of the polyurethane foam raw material M under pressure, and when the raw material M is injected into the roll mold 30, In order to generate a large number of microbubbles by moving to the atmospheric pressure state at once, the cell structure of the polyurethane foam 14 obtained from the raw material M is homogenized and the effect of improving the low density, that is, the foaming efficiency is exhibited. .
[0039]
The amount of various gases mixed and dissolved in the polyol component in the raw material preparation step S1 ([0025]) in the present invention is 10 to 10 by volume with respect to the polyol component. The range is set to 20 copies. If the mixing amount is less than 10 parts, it will be difficult to make the viscosity of the polyurethane foam raw material M and the density of the resulting polyurethane foam 14 suitable values, while if it exceeds 20 parts, dissolution and maintenance of the dissolved state will occur. The pressurization equipment required for the above becomes excessive, causing a problem that it is not suitable for actual use. In addition, as said various gas to dissolve, use of inert gas etc., such as a low boiling-point solvent, dry air, and nitrogen gas, is suitable.
[0040]
As for the air loading, the same effect can be expected for the viscosity by blowing the various gases into the polyurethane foam raw material M. However, the cells of the polyurethane foam 14 obtained from the polyurethane foam raw material M are inferior in the mixing / stirring property of the various gases, so that the homogeneity of the obtained cell structure is low and it is difficult to form minute cells. Therefore, it is not a preferable method.
[0041]
(Cure / Demolding Step S4)
In the curing / demolding step S4, a polyurethane foam raw material M injected in a predetermined amount, that is, about 12.6 to 42 g, into the roll mold 30 is foamed and cured to fill the annular space 16 14 and obtaining the tube roll 10 in which each of the external tube 12 and the shaft 18 is firmly joined, and removing the tube roll 10 from the roll mold 30 (see FIG. 5D). The cure for foaming and curing the polyurethane foam raw material M is set so that it can be completed in a short time without particularly heating due to the effects of the air loading and the room temperature reaction type catalyst described above.
[0042]
In addition, as a raw material of the polyurethane foam raw material M, a raw material that requires heat curing may be used. The curing is performed by performing predetermined heating on the roll mold 30. However, in this case, it should be noted that the heating temperature must be set to a temperature that can be withstood by the material of the outer tube 12 constituting the outer surface of the tube roll 10 to be obtained. In addition, depending on the material, the outer tube 12 should not be wavy due to volumetric expansion or the like, even though it is not melted by heating.
[0043]
(Final process S5)
In the final step S5, the tube roll 10 manufactured by going through the above-described steps S1 to S4 is subjected to post-processing such as cutting and polishing an excess portion, or there is no problem as a final product. This is a step of performing inspections on points.
[0044]
By going through all the steps S1 to S5 so far, the outer tube 12 and the shaft 18 that constitute a part of the tube roll 10 to be obtained, and the polyurethane foam raw material M, the outer tube 12 and the shaft 18 are respectively The tube roll 10 that is firmly bonded to the foamed / cured polyurethane foam 14, has high surface smoothness, and exhibits a good nip pressure that does not vary depending on the site can be easily manufactured.
[0045]
[Example of change]
In the above-described embodiment, the case where the tube roll 10 is manufactured using the roll forming die 30 including the plurality of forming split dies 32, 32 has been described. However, the present invention is not limited to this, for example, FIG. A so-called pipe-type roll forming die 40 as shown in FIG. In this case, the roll forming die 40 has an inner diameter that matches the length and outer diameter of the tube roll 10 to be obtained, that is, has an inner contour shape that matches the outer contour shape of the tube roll 10, and its inner circumference. A pipe-type body 42 in which the outer tube 12 can be disposed on the surface 42a, and an external tube disposed on both sides of the pipe-type body 42 to close the pipe-type body 42 and disposed in the pipe-type body 42 12 is basically composed of closing adapters 44 and 44 on which the shaft 18 can be arranged with the central axis aligned.
[0046]
The closing adapter 44 has, for example, a fitting structure that can be hermetically detachably disposed at both ends of the pipe-type main body 42, and the shaft 18 is inserted through a substantially axial center thereof, A shaft insertion hole 45 that can be arranged with its central axis lined up with the outer tube 12 arranged on the inner peripheral surface 42a is provided. Similarly to the roll mold 30, one of them is a raw material injection hole 46 for injecting the polyurethane foam raw material M into the annular space 16, and the other is injected into the annular space 16 by injection of the polyurethane foam raw material M. A plurality of discharge holes 48 for air or the like to be pushed out are formed.
[0047]
As the method of manufacturing the tube roll 10, only the installation of the outer tube 12 and the method of removing the obtained tube roll 10 in the member installation step S2 and the curing / demolding step S4 are different. And when using this roll forming die 40, unlike the roll forming die 30, it is not necessary to consider the transfer of the parting line P to the external tube 12, but depending on the material strength of the external tube 12, A substance having a thickness of less than 150 μm can also be preferably used. The inner surface of each of the closed adapters 44 and 44 is subjected to a process for improving peelability such as a fluorine process so that the tube roll 10 can be easily demolded after curing. Also good.
[0048]
[Another change]
In the above-described embodiments and modifications, the case where the roll forming die 30 or 40 having the inner contour shape that matches the outer contour shape of the tube roll 10 to be obtained has been described, but the present invention is not limited to this. Instead, for example, as shown in FIG. 7, the outer tube 12 itself that forms the outer surface of the tube roll 10 to be obtained may be used as a mold for the polyurethane foam 14. In this case, both ends of the outer tube 12 are substantially sealed with the fixed dies 50 and 50. The fixed mold 50 is provided with an outer tube fitting groove 54 and a shaft insertion hole 55 that can arrange and position the outer tube 12 and the shaft 18 by aligning the central axis thereof (FIG. 7A). reference). Similarly to the closed adapter 44 and the like, a raw material injection hole 56 for injecting the polyurethane foam raw material M into the annular space 16 is provided on one side, and the other inside the annular space 16 by injection of the polyurethane foam raw material M on the other side. A plurality of discharge holes 58 for air or the like to be pushed out are formed.
[0049]
As the manufacturing method of the tube roll 10, the external tube 12 is installed in the member installation step S2, the curing / demolding step S4, and the final step S5, and the resulting demolding method of the tube roll 10 and the external tube 12 are obtained. The only difference is the cutting of the portion fitted to the fixed mold 50. By using the fixed dies 50 and 50, the tube can be more easily used without using the roll forming dies 30 and 40 having the inner peripheral surfaces accurately provided as in the above-described embodiments and modified examples. The roll 10 can be manufactured. On the other hand, in order to withstand the volume expansion of the polyurethane foam 14 obtained by foaming / curing, it is necessary to pay attention to the fact that the thickness of the outer tube 12 is about 100 μm or more although it depends on the material. It should be noted that the inner surfaces of the fixed dies 50, 50 may be subjected to processing for improving the peelability such as fluorine processing so that the tube roll 10 can be easily removed after curing. Good.
[0050]
【The invention's effect】
  As described above, the tube flow according to the present invention.LeAccording to the manufacturing method, the prepared outer tube and shaft are installed inside a required mold or the like, and the polyurethane foam raw material is injected into the annular space defined between the outer tube and shaft, and foamed and cured. Polyurethane foam, and each of the outer tube and the shaft is configured to be joined to the foamed / cured polyurethane foam, so that the manufacturing process can be simplified to shorten the lead time and the initial equipment. A tube roll that can express both high surface smoothness and good nip pressure can be easily produced. Further, since it is not necessary to polish polyurethane foam and use an adhesive component, there are effects of reducing raw material costs and stabilizing the physical properties of the obtained tube roll.
[0051]
Further, by applying air loading to the polyurethane foam raw material, the viscosity can be lowered and the foaming efficiency can be improved. Therefore, the diameter of the polyurethane foam raw material is small, corresponding to the recent downsizing. A good tube roll can also be produced when using a mold having a small injection clearance.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a tube roll according to a preferred embodiment of the present invention with a part cut away.
FIG. 2 is a process diagram showing a method for manufacturing a tube roll according to an embodiment.
FIG. 3 is a schematic perspective view showing an open state (a) and a closed state (b) of a roll forming die for forming a tube roll according to an embodiment.
FIG. 4 is a schematic view showing a production mechanism for producing a tube roll according to an embodiment.
FIG. 5 is a schematic view showing a production method for producing a tube roll according to an example for each step.
FIG. 6 is a schematic view showing a state (a) before installing the external tube and the shaft in the roll forming die according to the modified example, and a state (b) after installing.
FIG. 7 is a schematic view showing a state (a) before installing an external tube and a shaft in a fixed mold according to another modification, and a state (b) after installing.
FIG. 8 is a schematic view showing a manufacturing method for manufacturing a tube roll according to the prior art for each step.
[Explanation of symbols]
12 External tube
14 Polyurethane foam
16 Annular space
18 shaft
30 Roll mold
32 roll forming mold
34 Inner surface
40 roll mold
42a inner peripheral surface
50 Fixed type
M Polyurethane foam raw material

Claims (7)

Prepare the outer tube (12) with both ends open at the outer diameter matched to the outer diameter of the tube roll, install the fixed mold (50, 50) so as to close both ends of the outer tube (12), The shaft (18) is inserted and arranged with the central axis aligned with the outer tube (12),
In the annular space (16) defined by the fixed mold (50) and defined between the outer tube (12) and the shaft (18), one fixed mold faces the annular space (16). The polyurethane foam raw material (M) that has been air-loaded in advance is injected through the raw material injection hole (56) provided in (50), and the other fixed mold (50) is exposed to the annular space (16). The air in the annular space (16) is discharged through the discharge hole (58) provided by
By foaming and curing the polyurethane foam raw material (M), the annular space (16) is filled with polyurethane foam (14),
Then, the external tube (12) and the shaft tube, respectively (18) are joined before Symbol foam-cured polyurethane foam (14) roll (10), to detach from the fixed mold (50, 50) A method of manufacturing a tube roll, characterized in that An outer tube (12) having both ends opened is installed on the inner peripheral surface (34, 42a) of the roll forming die (30, 40) having an inner contour shape that matches the outer contour shape of the tube roll. Align the central axis with (12) and insert the shaft (18) through it,
The annular space (16) defined between the said shaft (18) in the interior of said outer tube both end surfaces in the roll mold (30, 40) is blocked (12), said outer tube ( to face the one end face 12) while injecting a roll mold (30, 40) advance air loading through the material injection hole (36, 46) provided in the the implementation polyurethane foam raw material (M) The air in the annular space (16) is discharged through the discharge holes (38, 48) provided in the roll mold (30, 40) so as to face the other end surface of the outer tube (12),
By foaming and curing the polyurethane foam raw material (M), the annular space (16) is filled with polyurethane foam (14),
Then, the external tube (12) and the shaft tube, respectively (18) are joined before Symbol foam-cured polyurethane foam (14) roll (10), removed from the roll mold (30, 40) A method of manufacturing a tube roll, characterized in that it is configured as described above. The method for producing a tube roll according to claim 1 or 2, wherein a normal temperature reaction type catalyst is added to the polyurethane foam raw material (M) . The manufacturing method of the tube roll as described in any one of Claims 1-3 with which the width | variety in the radial direction of the tube roll (10) which the said annular space (16) should obtain is set to the range of 1-10 mm. The manufacturing method of the tube roll as described in any one of Claims 1-4 with which the injection | pouring flow volume with respect to the said annular space (16) of the said polyurethane foam raw material (M) is set to the range of 0.3-10 g / min. . The addition amount of various gases mixed by the air loading is set in a range of 10 to 20 parts by volume with respect to a polyol component which is one of main raw materials of the polyurethane foam raw material (M). The manufacturing method of the tube roll as described in any one of 1-5 . The method of manufacturing a tube roll according to claim 2, wherein a mold comprising a plurality of split molds (32) is used as the roll mold (30).

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