JPS58203471A - Heat roll fixation device - Google Patents

Abstract

PURPOSE:To improve the heat conductivity and reduce the damage of the surface of a roll, by plating the surface of the metallic roll with chromium to form a roll. CONSTITUTION:The surface of a metallic roll 1 is plated with chromium 3 with a thickness of 3-15mu. In case that materials of the metallic roll are iron, it is necessary to plate not only the surface of the roll 1 but also an inside wall face 4 and all of the surface of a journal 5 with chromium for the purpose of preventing rust. When the coat thickness of chromium plating is 3-15mu, the time for chromium plating is shorter, and the surface precision of the metallic roll before chromium plating is not degraded and is held. Further, since the heat conductivity of chromium is higher than that of a polytetrafluoroethylene and a silicone rubber and the surface of the metallic roll can be coated thinly with chromium, heat from a heating source incorporated in the roll is transmitted to a toner image early.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is used in electronic copying machines, facsimile machines, printers, etc., to reduce toner images formed on a support such as paper between a pair of rolls, one of which has a heating mechanism, which are brought into mutual contact with each other. The present invention relates to a heat roll fixing device for fixing.

Conventionally, as a fixing roller and a pressure roller in a heat roll fixing device, for example, Japanese Patent Publication No. 54-1934
As described in Japanese Patent Publication No. 7, Japanese Patent Application Laid-Open No. 55-129370, etc., a roller coated with silicone rubber or tetrafluoroethylene pattern fat is used.

In other words, the conventional heat roll, as shown in Figure 1,
A coating layer 2 made of tetrafluoroethylene resin or silicone rubber is formed on the surface of a metal roll 1 to prevent heat-resistant toner images from adhering to the roll surface and to prevent rust. .

However, the coating material has poor thermal conductivity, and due to the manufacturing method,
Because it has to be coated as thick as 0 to 40 μm, '? M.K.
- Provides a barrier to conduct heat from a heating source contained within the roller to the toner image.

Furthermore, the above-mentioned coating material is an elastic body and is not satisfactory in terms of shore abrasion resistance, and the member for separating the support such as paper from the roller surface does not damage the coating layer on the roller surface. Therefore, it is not easy to select the material and shape.

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat roll fixing device that eliminates the above-mentioned drawbacks of the prior art and has good thermal conductivity and is resistant to scratches on the roll surface.

The details of the present invention will be explained below with reference to the drawings.

FIG. 2 is a sectional view of a heat roll used in the heat roll fixing device of the present invention. Pipe-shaped metal roll
Chromium plating 6 is applied to the surface with a thickness of 3 to 15 μm. In this case, the material of the metal roll is iron,
Applicable materials include stainless steel and aluminum. However, since chromium has a small coefficient of thermal expansion, iron and stainless steel have better adhesion than aluminum. In the case of iron, it is necessary to chrome plate not only the roll surface 1 but also the entire inner wall surface 4 and journal 5 for rust prevention. The thickness of chrome plating is 6
Between .mu. and 15 .mu., the time required for coating the chrome metal is short, and furthermore, it is possible to maintain precision without deteriorating the surface precision of the metal roll before chrome plating.

In addition, the thermal conductivity of chromium is better than that of tetrafluoroethylene resin and silicone rubber, and since it can be coated thinly on the surface of a metal roll, it can quickly absorb heat from a heating source (not shown) built into the roller. can be transferred to the toner image.

[Brief explanation of drawings]

Figure 1 is a sectional view showing an example of a conventional heat roll;
The figure is a sectional view showing a heat roll according to the present invention. 1: Metal roll, 2: Tetrafluoroethylene resin or silicone rubber, 3 Nichrome plating, 4: Roll inner wall surface, 5:
roll journal

Claims (1)

[Claims] 1. A heat roll fixing device comprising a pair of rollers that rotate in mutual contact with each other, at least one of which is in a heated state, and at least one of the rollers is formed by plating the surface of a metal roll with chrome.