Process method for improving fixing effect of ceramic heating bar

Abstract

To provide a process method for improving the fixing effect of ceramic heating bar relates to a field of ceramic heating bar.SOLUTION: A method includes the steps of: (1) printing electrode material on both ends of an upper surface of an alumina ceramic substrate, drying, and sintering to form electrodes; (2) printing heating paste on the alumina ceramic substrate so that the heating paste connects the electrodes at both ends, and drying and sintering the heating paste to form a heating wire; (3) printing glass paste on an undersurface of the alumina ceramic substrate, and drying and sintering the glass paste to form a rear glass layer; and (4) printing the glass paste on the heating paste, and drying and sintering the glass paste to form a front glass layer.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention belongs to the technical field of ceramic heating bars, and specifically relates to a process method for improving the fixing effect of ceramic heating bars.

Background Art

[0002] Current fixing devices for laser printers have two important heating members: a tungsten filament heating tube and a ceramic heating bar.

[0003] The heating device used in the fixing device of a conventional laser printer is a lamp heater that provides a heat source by utilizing the principle of passing an electric current through a tungsten wire to dissipate heat. The ceramic heating bar has advantages such as a faster heating rate, uniform heat, shortening of the first print time, and a long service life compared with tungsten wire heating, and thus has become the first choice material for the heating member of a laser printer.

[0004] The ceramic heating bar is mainly composed of a ceramic substrate, electrodes, heating wires, and glass glaze. It also provides a heat source by utilizing the principle of passing an electric current through the heating wires to dissipate heat, and releases heat from the glass layer. The toner adsorbed on the printing medium is melted and embedded in the surface of the printing medium by pressure heat fusion to form a fixed printed file. Compared with the lamp tube, the ceramic substrate has characteristics such as good thermal conductivity, high thermal conductivity, and high temperature resistance, and can dissipate the heat of the entire heating device faster.

[0005] The ceramic heating bar has many excellent properties, but there are problems with safety and reliability during use. The ceramic heating bar is based on an alumina ceramic substrate. The thermal conductivity of the alumina ceramic substrate is ≧21 W / (m*K), and the thermal conductivity of the upper glass glaze is only 2 - 5 W / (m*K). Since the thermal conductivity of the alumina ceramic substrate is 4 - 10 times that of the glass glaze, the heat generated after energizing the heating wire is easily dissipated from the ceramic substrate. Therefore, the glass glaze layer in contact with the paper has low heat and low fixing strength. Due to the large difference in thermal conductivity between the ceramic substrate and the glass glaze, most of the heat is dissipated from the alumina ceramic substrate and wasted. In order to achieve the desired fixing effect, it is necessary to search for a glass glaze with high thermal conductivity, which increases the cost.

Summary of the Invention

[0006] In view of the above circumstances, in order to overcome the defects of the prior art, the present invention provides a process method for improving the fixing effect of a ceramic heating bar, thereby effectively solving the problem of the poor fixing effect of the conventional ceramic heating bar.

[0007] To achieve the above object, the technical means of the present invention are as follows.

[0008] A process method for improving the fixing effect of a ceramic heating bar, comprising: (1) Printing electrode material on both ends of the upper surface of the alumina ceramic substrate, drying, and sintering to form electrodes; (2) Printing a heating paste on the alumina ceramic substrate so that the heating paste connects the electrodes at both ends, drying, and sintering to form a heating wire; (3) Printing a glass paste on the lower surface of the alumina ceramic substrate, drying, and sintering to form a back glass layer; (4) Printing a glass paste on the heating paste, drying, and sintering to form a front glass layer. A process method including the above steps.

[0009] Furthermore, in the step (1), the main component of the electrode material is AgPt.

[0010] Furthermore, in the step (1), the drying temperature is 100 - 150°C, and the sintering temperature is 830 - 880°C.

[0011] Furthermore, in the step (2), the main component of the heating paste is AgPt, and the temperature coefficient of resistance (TCR) is 200 - 600 ppm / °C.

[0012] Furthermore, in the step (2), the drying temperature is 100 - 150°C, and the sintering temperature is 830 - 880°C.

[0013] Furthermore, in the steps (3) and (4), the solids in the glass paste are Al2O3 with a content > 40%, SiO2 with a content of 18%, B2O3 with a content of 15%, ZnO with a content of 5%, and BaO with a content of 15%, and the solid content of the glass paste is 70%.

[0014] Furthermore, in the steps (3) and (4), the drying temperature is 100 - 150°C, and the sintering temperature is 800 - 860°C.

[0015] Furthermore, in the step (3), one layer of glass paste is printed using a 325 - mesh 40 - μm screen, and the thickness of the sintered film is 8 - 10 μm.

[0016] Furthermore, in the step (4), 5 - 7 layers of glass paste are printed using a 200 - mesh 40 - μm screen, and the thickness of the sintered film is 60 - 80 μm.

[0017] Furthermore, in order to avoid the back - side glass layer directly contacting the rollers of the sintering furnace and affecting the surface quality, when sintering the front - side glass layer in step (4), the back - side glass layer is placed on a holder.

[0018] Furthermore, the holder includes a pad plate and at least two beams, and the two beams are provided on the upper surfaces at both ends of the pad plate in parallel with each other.

[0019] Furthermore, the beam is fixedly connected to the upper surface of the pad plate.

[0020] Compared with the prior art, the present invention has the following beneficial effects.

[0021] According to the present invention, a ceramic heating bar with improved fixing effect and its process method are provided. During use, a layer of back glass layer is printed on the back surface of the alumina ceramic substrate. Thereby, heat dissipation from the alumina ceramic substrate is reduced, and heat release from the front glass layer is ensured. Therefore, the heating effect is improved, the fixing effect is improved, and the cost is significantly lower than when using a high thermal conductivity glass layer on the front surface. In the present invention, after printing and sintering the back glass layer, the front glass layer is printed and sintered. By this, in the sintering process, the front glass layer is sintered again, so that the front glass layer extends and the size becomes larger, and it is avoided that the edge is not neat.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

[0023] Description of Reference Signs 1. Back glass layer, 2. Alumina ceramic substrate, 3. Electrode, 4. Heating wire, 5. Front glass layer, 6. Holder, 7. Pad plate, 8. Beam.

Embodiments for Carrying Out the Invention

[0024] A process method for improving the fixing effect of a ceramic heating bar includes the following steps as shown in FIG. 1.

[0025] (1) Print the electrode material at both ends of the upper surface of the alumina ceramic substrate 2. The main component of the electrode material is AgPt. The electrode material is a paste-like substance with a uniform color and has good weldability. After printing, place the product in a drying box at 100 - 150 °C for drying, and then put it into a sintering furnace at a temperature of 830 - 880 °C for sintering to form the electrode 3. After sintering, the electrode layer is silver-colored and shiny.

[0026] (2) Print the heating paste on the alumina ceramic substrate 2. The heating paste connects the electrodes 3 at both ends and generates heat when energized. The main component of the heating paste is AgPt, it is a paste-like substance with a uniform color, and the resistance temperature coefficient (TCR) is 200 - 600 ppm / °C. After printing, place the product in a drying box at 100 - 150 °C for drying, and then put it into a sintering furnace at a temperature of 830 - 880 °C for sintering to form the heating wire 4. After sintering, inspect the surface of the heating wire 4 to ensure that there are no short-circuit or open-circuit phenomena. Detect the resistance with a resistance tester.

[0027] (3) To delay the heat dissipation from the back of the ceramic, print a layer of glass paste on the lower surface of the alumina ceramic substrate. The solids in the glass paste are Al2O3 with a content > 40%, SiO2 with a content of 18%, B2O3 with a content of 15%, ZnO with a content of 5%, and BaO with a content of 15%. The solid content of the glass paste is 70%. Use a 325-mesh 40-μm screen to print a layer of glass paste. The thickness of the sintered film is 8 - 10 μm. After printing, place the product in a drying box at 100 - 150 °C for drying, and then put it into a sintering furnace for sintering. The temperature of the sintering furnace is 800 - 860 °C. After sintering, the glass layer is uniformly transparent, and the back glass layer 1 is formed. Specifically, for the printing of the back glass layer 1, a 4-mm-wide protective edge where no glass paste is printed is provided at the edge of the alumina ceramic substrate 2. That is, it is not printed so as to cover the entire back surface of the alumina ceramic substrate 2.

[0028] (4) Mainly for insulation and heat conduction, 5 - 7 layers of glass paste are printed on the heating paste. The main components of the glass paste are the same as in step (3). A 200 - mesh 40μm screen is used to print 5 - 7 layers. The thickness of the sintered film is 60 - 80μm. After printing, the product is placed in a drying box at 100 - 150°C for drying, and then put into a sintering furnace at a temperature of 800 - 860°C for sintering to form the front glass layer 5.

[0029] In this embodiment, in order to avoid the back glass layer 1 directly contacting the rollers of the sintering furnace and affecting the surface quality, in step (4), when sintering the front glass layer 5, the back glass layer 1 is placed on the holder 6. The holder 6 includes a pad plate 7 and at least two beams 8. The two beams 8 are provided on the upper surfaces at both ends of the pad plate 7 in parallel to each other. On the edges at both ends of the alumina ceramic substrate 2, there are provided protective edges with a width of 4mm where no glass paste is printed. The distance between the beams 8 is longer than the length of the back glass layer 1. Specifically, when sintering, the bottom surface of the pad plate 7 is placed on the rollers of the sintering kiln, and the protective edges where no glass paste is printed on the alumina ceramic substrate 2 are placed on the upper surfaces of the beams 8, thereby avoiding the back glass layer 1 contacting the holder 6 and affecting the surface quality of the back glass layer 1 during the sintering process. In another embodiment, the two beams 8 are provided on the upper surfaces on both sides of the pad plate 7 in parallel to each other. On the edges on both sides of the alumina ceramic substrate 2, there are provided protective edges with a width of 4mm where no glass paste is printed. The distance between the beams 8 is longer than the width of the back glass layer 1. In another embodiment, the two beams 8 are provided on the upper surfaces on both sides or both ends of the pad plate 7 in parallel to each other. On the peripheral edges of the alumina ceramic substrate 2, there are provided protective edges with a width of 4mm where no glass paste is printed.

Claims

1. A process method for improving the fixing effect of a ceramic heating bar, comprising: (1) printing an electrode material at both ends of the upper surface of an alumina ceramic substrate, drying, and sintering to form electrodes; (2) printing a heating paste on the alumina ceramic substrate so that the heating paste connects the electrodes at both ends, drying, and sintering to form a heating wire; (3) printing a glass paste on the lower surface of the alumina ceramic substrate, drying, and sintering to form a back glass layer; (4) printing a glass paste on the heating paste, drying, and sintering to form a front glass layer. The process method is characterized by including the above steps.

2. The process method according to claim 1, wherein in the step (1), the main component of the electrode material is AgPt.

3. The process method according to claim 2, wherein in the step (1), the drying temperature is 100 - 150°C and the sintering temperature is 830 - 880°C.

4. The process method according to claim 1, wherein in the step (2), the main component of the heating paste is AgPt and the temperature coefficient of resistance (TCR) is 200 - 600 ppm / °C.

5. The process method according to claim 4, wherein in the step (2), the drying temperature is 100 - 150°C and the sintering temperature is 830 - 880°C.

6. In the steps (3) and (4) above, the solids in the glass paste are Al with a content > 40%, ２ O ３ , SiO with a content of 18%, ２ , B with a content of 15%, ２ O ３ , ZnO with a content of 5%, and BaO with a content of 15%, and the solid content of the glass paste is 70%, and the process method according to claim 1 is characterized by this.

7. The process method according to claim 6, wherein in the steps (3) and (4), the drying temperature is 100 - 150°C and the sintering temperature is 800 - 860°C.

8. The process method according to claim 7, wherein in the step (3), one layer of glass paste is printed using a 325-mesh 40-μm screen, and the thickness of the sintered film is 8 - 10 μm.

9. The process method according to claim 7, wherein in the step (4), 5 - 7 layers of glass paste are printed using a 200-mesh 40-μm screen, and the thickness of the sintered film is 60 - 80 μm.

10. The process method according to claim 1, wherein in the step (4), when sintering the front glass layer, the back glass layer is placed on a holder.

11. The holder according to claim 10, characterized in that it includes a pad plate and at least two beams, and the two beams are provided on the upper surfaces at both ends of the pad plate in parallel with each other.

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