JPS5835573A - Fixing device - Google Patents

Abstract

PURPOSE:To absorb the ruggedness of a recording paper to fix a image with a comparatively low pressure, by providing a surface coating layer, where the elongation percentage and the tension elastic constant are within specific ranges, on a base material, where the surface roughenss is within a specific range, to constitute a pressure roll. CONSTITUTION:In a fixing device which carries a supporting material 5 such as a recording paper, where an unfixed image 6 is supported, while holding the supporting material 5 between rotary materials (for example, a pressure roller 4 and a pressure roller 1 to fix the image in the supporting material 5, the pressure roller 1 is constituted by providing a surface coating layer 12, where the elongation percentage is >=50% and the tension elastic constant is 10- 1,000kg/mm.<2>, on a base material 11 where the surface roughness is 0.5-100S. For example, the surface of the carbon steel roller after the finishing work is worked into said surface roughness by the shot blast, and a super molecular weight polyethylene is blown to the surface to form the polyethylene layer 12 having a thickness of 30mum, and the pressure roller 1 produced in this manner is used.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fixing device used in an image forming apparatus, etc. Conventionally, methods for supporting a toner image and fixing a support material include a pressure fixing method, a pressure heat fixing method, and a heat fixing method. A fixing method is used. Among these, in an apparatus that performs fixing mainly or in combination with m pressure, it is a preferable condition to apply uniform pressure to the toner particles of the support material.

However, in the conventional apparatus mentioned above, when the supporting material is paper or the like, toner particles get stuck between the fibers, making it impossible to apply uniform pressure. .

This appears to be a significant factor in the deterioration of fixing performance.

Therefore, in pressure fixing devices, devices have been proposed that apply pressure that greatly exceeds the pressure that is originally used for fixing KLItPIF to improve fixing performance, but this may cause the support material to curl, resulting in the support material and image becoming glossy. However, the support material partially became transparent.

SUMMARY OF THE INVENTION An object of the present invention is to provide a fixing device that eliminates the conventional drawbacks, absorbs the unevenness of a support material, has a μ rotary body sufficient for the unevenness, and enables fixing with relatively light pressure. It is.

Incidentally, the unevenness of the supporting material refers to the density unevenness of the fibers of the No. 1 K paper, which is large with a pitch of about 0.1 to 3.0, and secondly, the unevenness of the paper fibers themselves. It shows irregularities, and the size includes both those with a pitch of about 5 to 30 μm.

Hereinafter, the present invention will be explained in more detail with reference to the drawings. FIG. 1 is a sectional view of a main part of an embodiment of the present invention. 1 is a pressure roller, the details of which will be described later. 4 is a pressure roller that comes into pressure contact with this pressure roller, and its base surface is superfinished and the front and rear surfaces are further plated with hard chrome. A support material 5 having a toner layer 6 between the rollers
Excellent pressure fixing is achieved by allowing the film to pass through.

Although not shown in FIG. 1, a pair of pressure rows 2
The pressure roller 1 has a rounding drive mechanism for driving the roller and a mechanism for cleaning the off-pressure roller 4. Next, the pressure roller 1 will be described in detail with reference to FIG. 2.3. FIG. 2 shows the surface 20 of the base body 11 of the pressure roller.
This is an explanatory diagram showing the degree of unevenness, and FIG. 3 is an enlarged view of the main part of FIG.

First, the base 1 with a constant pressure. The base body 11 of the 0-pressure car 21 to be described is made of carbon steel and its surface is buffed to a sufficient finish for both cylindricity and roundness. It is processed into.

011311 Pressure after processing - Fine and random irregularities such as No. 2E are formed on the surface of the substrate 11. Regarding such a surface, in the present invention, the following surface I
Figure 2 shows the data from a micro surface roughness meter sold by Tirasepurin Co., Ltd., Kosaka Institute, etc. Here, the surface roughness is the JISIO point average roughness.
Rz) (JIS B 0601).

In other words, as shown in Fig. 3, the average INK of the section extracted by the reference length t from the cross-sectional curve is a straight line parallel to the one that passes through the third peak from the highest one and the one that passes through the third valley bottom from the deepest one. The distance between two straight lines is measured using a micrometer (μ information)
It is represented by a round piece, and the standard length L-0,25-stitch 9. In addition, the pitch is counted as one mountain if the height of the convex part is 0.1μ or more with respect to the concave parts on both sides, and the standard length is 0.2
It was calculated as follows based on the number of mountains in 5-.

250 (J4/ Number of peaks included in 250 (b)) The value obtained by the above formula is the surface roughness of the base 11, and the surface roughness value in the range of 0.5 to 1008 that is compatible with the present invention. Can be measured.

For rough surfaces such as ζO, it is not necessary to use only the sheet-plast method, but rather to use etching, metal spraying, etc., which are well-known metal surface processing methods, to achieve a surface roughness of 0.5 to 1008.
Even if the surface is processed, it will not be too stormy, and it will be difficult to use carburizing, nitriding, heat treatment hard plating, etc. to harden the surface.

Next, the base 1. A coating layer 1°, which is to be soldered onto the substrate 1. The elastic modulus is smaller than that of the rough surface.

In this example, ultra-high molecular weight polyethylene is sprayed in the blasting direction with a roughness of 108 to form a polyethylene layer with a thickness of 30#IIl, which is made of a material that has sufficient strength even during plastic deformation.

Using the above device, pressure roller 1 and pressure roller 4 were applied so as to apply a linear pressure of 10- to the support material, and the microcapsule toner, which had not been fixed even when 4 was applied to the linear pressure of 15, was completely removed. It is now possible to fix more uniformly with light pressure than conventional methods. The improvement in fixing performance during the fixing action in the pressure contact portion 3 will be explained. The nip portion 3 formed by this roller 1.4 (if the rollers 1.4 are arranged at intervals, this indicates the pressure contact area during the pressure fixing action)
In the case of the substrate 1., the thin layer 11 has a relatively small thickness and is relatively **L. Since the nip portion 3 is provided so as to fit into the recessed portion of the rough surface of the nip portion 3, the area of the nip portion does not increase and pressure can be effectively applied to the nip portion 3.

In addition, in this nip portion 3, the rough surface of the AB body 1 is slightly deformed along with the coating layer 1 due to pressure and the presence of the support material, toner image, etc., so the coating layer 18 is made to conform to the irregularities of the support material. Partial deformation occurs as if it were being pulled out of a recess in the rough surface. This partial deformation can penetrate even minute irregularities formed between paper fibers among the irregularities of the support material, making it possible to achieve excellent pressure fixing. Furthermore, the pressure applied at this time is applied to the coating layer 1.
Even if partial deformation occurs due to plastic deformation of the snow covering layer 1, a portion of the stress exceeds the yield stress of the paper and is sufficient to even out the irregularities between the paper fibers.

Therefore, the coating layer 1. is thus formed on the substrate 11. By providing this, it is possible to compensate for even small uneven pitches of 5 to 30 microns on the support material, enabling excellent pressure fixing, and even with light pressure, the efficiency can be improved to almost 100 - evenly rounded and fixed. It is possible to obtain a toner image with a lighter pressure than before.

Therefore, it is possible to provide an extremely excellent fixing device that has the advantage of being lightweight and compact. Next, the coating layer 1 in the base 11 can be provided. The properties and materials suitable for this will be explained using FIG.

The above substrate 1. When it comes to binding, the main focus is on the material of both the front and the front parts, as well as the overall material, but as mentioned above, the surface roughness is 0.5. It is preferable if the surface roughness is processed to a surface roughness of 1 to 1008 and has a roughness of 94 or that. ), and exhibits more stable adhesion and excellent fixing properties without deterioration of durability due to deformation.&J) is a more preferred embodiment. Furthermore, the ceramic surface may be etched annealed and hardened by impurity hardening and precipitation hardening. Even in such a case, the surface of the upper two honeycombs 2 should be roughened to about 0.5 to 1 oos.

Also, a so-called porous heavy rank may be used.If such a rough surface is soft, it may be damaged by hard magnetic powder such as magnetite in the toner. Ninth, it is preferable that the rough surface has a Vickers hardness of 200 (Hv) or more according to JISs2244.

Regarding the above-mentioned covering layer t, it is necessary that the elastic constant of the material thereof is not so large. This is because, if we take ordinary rubber and plastics as an example, rubber has a small elastic constant and is difficult to deform plastically, whereas plastics cannot be called an elastic body, but they have elasticity and deform plastically. It still has considerable strength.

FIG. 4 shows a stress elongation diagram of this type of material. 7 is an elongation diagram of plastics, and 8 is an expansion diagram of rubber.

As is clear from Figure 4, rubber, etc., has a small elastic constant and is difficult to plastically deform.Rather than deforming into the paper fibers, the elastic material protrudes out to both ends of the nip, directly contacting the hard rough surface of the base. It ends up looking like paper.

Further, if the coating layer is made thicker to prevent such a phenomenon, the nip portion increases and pressure is not effectively applied to the member to be fixed, resulting in a significant decrease in fixing efficiency and fixing effect. On the other hand, plastics have only slight partial deformation.
Furthermore, since its plastic deformation is moderate under high pressure, it can even compensate for the unevenness of paper fibers with a pitch of 5 to 30μ. Furthermore, the fixing effect is improved.

From the above comparative experiments, the coating layer 11 should firstly be deformed to follow the irregularities of the supporting material such as paper during the fixing action, and secondly be sufficiently durable against fatigue caused by this deformation. Thirdly, it is desirable that the stress range for the plastic deformation region is relatively wide.In general, elastic constants include tensile elastic constant, compressive elastic constant, bending elastic constant , rigidity, etc. are defined, but these values are not all independent constants.

Here, we take the tensile elastic constant, which is the most common elastic constant among these, and when we apply tensile deformation to plastics, which represents the elastic constant of the material, the stress and elongation become 5 as shown in Figure 4. When the stress is increased, the elongation increases and this slope becomes the tensile elastic constant. When the stress is further increased, it yields at Y, and the elongation at this time is expressed as a value called elongation percentage. Generally, a linear pressure of 10 to 40 kG/cm is applied during fixing. This is a surface pressure of 80 to 500 kQ/am. With such pressure, the contouring effect is 10 to 100 PEEI.
Sha10~1 (100IQ/'III
It is sufficient to have a compressive elastic constant of m. Although the compressive elastic constant and the tensile elastic constant have different values, the tensile elastic constant also has a value of 10 to 1000 k4ij/-, and as a result of experiments, it has been determined that a good tracing effect can be obtained. Also elongation rate 5
The one with zero drops had poor durability and was not suitable for long-term use. Similarly, the tensile elastic constant is less than 9/m, 100
0 kl;J/wa Yo! If I is large (1), it may actually reduce the fixing effect, which is undesirable.Even other than 0 ultra-high molecular weight polyethylene, those classified as elongation of 50- or more and tensile elastic constant of 10 to 1000 Et/- are All had good effects in compensating for the unevenness of the paper sheet. For example, for several types of polyethylene, fluororesin, nylon, vinyl chloride, urethane, vinylidene chloride, polyester, polycarbonate, polypropylene, butadiene, flexible silicone, and epoxy resin, use a toner that fixes at a linear pressure of 15 (-).・It was confirmed that those within the specified range showed partial surface deformation, had exceptional effects, and had improved fixability compared to conventional products.Furthermore, the elongation rate was 5016. The above materials had sufficient durability against plastic deformation. Normally, rubber has an elastic constant of 10-2- or less and is easily deformed elastically, but difficult to deform plastically and easily breaks when plastically deformed.Elasticity Those with a constant of 10h/IIJ to 100047- have a relatively low yield point and are suitable for the present invention.〇〇9 In the present invention, the roller surface layer is deformed according to the unevenness of the paper, so the elongation rate is 50 inches or more. It is preferable to use a material with high strength. Also, dipping is the method of applying these plastic layers on a rough surface.

Coating techniques such as spraying, vapor deposition, and sherin couple tubes can be used.

Further, the thickness of this coating layer has a profiling effect from 0.5 to 5 times the roughness of the rough surface, but is preferably in the range of 1 to 3 times, as this further improves the profiling effect. Also, if the thickness is 5 times or more, the surface material will be more susceptible to scratches, etc., and after long-term use, each crack in the surface layer will result in only a surface layer 4 to 5 times the thickness remaining on the reeler. It happens.

As described above, the present invention provides a coating layer on a substrate having surface roughness and has the elongation rate and tensile elastic constant as described above, so that the surface coating layer has durability due to plastic deformation. This solves the conventional drawbacks of the rotor being deteriorated and peeling off from the substrate.Furthermore, the present invention can provide a rotary body that is highly durable and has an excellent tracing effect on the support material, and a fixing device having the same. The fixable pressure state of the toner particles can be reduced to a light pressure, and unevenness formed by the support material or the like can be absorbed by the rotating body, and uniform pressure can be applied to the toner particles to achieve good fixing. In addition, it is possible to provide a fixing device that performs fixing with a relatively light linear pressure of 20 It/- or less, which eliminates the conventional pressure that causes paper to curl or paper with a glossy surface to become transparent as described above. It is now possible to provide a fixing device that eliminates the drawbacks of the fixing device.

The present invention can also be applied to a heat fixing device, and in this case, it has the same effect as pressure fixing and the effect of reducing the amount of heat.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a main part of an embodiment of the present invention, Fig. 2 is an explanatory drawing showing the surface roughness of a pressure roller, and Fig. 3 is an enlarged view of a part of Fig. 2. In the explanatory drawings, FIG. 4 is a stress elongation diagram of rubber and plastic. 1 is a pressure roller; is the base, 1. 3 is the nip part (pressing area), 4 pressure rollers, 5 is the support material, 6
Roaring Toner statue.

Claims (1)

Scope of Claims: (1) In a fixing device that transports a supporting material supporting an unfixed image between rotating bodies and fixes the unfixed image onto the supporting material, a rotation having a surface roughness of 0.5 is provided. A fixing device characterized by having a body. (2) The fixing device according to claim 1, wherein the surface-laminated layer has a thickness corresponding to 0.5 to 5 times the surface roughness of the base. (8) The fixing device according to claims 1 and 2, wherein the base has a surface hardness of 200 Hv or more.