GB2059013A

GB2059013A - Covered rollers

Info

Publication number: GB2059013A
Application number: GB8030198A
Authority: GB
Original assignee: KATSURA ROLLERS Manufacturing CO Ltd; Dainippon Screen Manufacturing Co Ltd
Current assignee: KATSURA ROLLERS Manufacturing CO Ltd; Dainippon Screen Manufacturing Co Ltd
Priority date: 1979-09-18
Filing date: 1980-09-18
Publication date: 1981-04-15
Also published as: FR2465663B1; GB2059013B; FR2465663A1; JPS605133Y2; NL8005177A; DE3035117A1; JPS5645618U

Abstract

A covered roller comprises a core 1 molded from a mixture of synthetic resin, graphite, and glass fiber and/or carbon fiber. Such a roller is light in weight and has good heat and chemical resistance. The synthetic resin for the core 1 may be nylon, polyester, epoxy, diallylphthalate or phenol and may be formed as a solid or as a tube. The cover 2 may be made of rubber, soft acrylonitrile rubber or soft vinyl chloride resin. <IMAGE>

Description

SPECIFICATION Improvements in rollers This invention relates to rollers or rolls and more particularly to rolls which are much lighter in weight than the conventional ones and have better heat and chemical resistances.

Conventional rolls have a roll core of metal, wood or synthetic resin and a covering of an elastic member such as rubber mounted on the roll core. Such conventional rolls had shortcomings in weight and/or heat and chemical resistances. The ones having a roll core of metal such as iron or stainless steel are very heavy. The ones having a roll core of light metal such as aluminum or magnesium are lightweight but have poor chemical resistance to acids, bases or salts. Light metal such as titanium has a good corrosion resistance but makes the roll expensive. With a roll core made of synthetic resin only, heat resistance is incompatible with chemical resistance. Also, wooden roll cores are difficult to maintain dimensional accuracy and have poor heat and chemical resistances.

An object of the present invention is to provide rolls which alleviate the above-mentioned shortcomings and which are lighter in weight and have satisfactory heat and chemical resistances.

In accordance with the present invention, the roll core is made of a mixture comprising at least one kind of synthetic resin, graphite, and glass fiber and/or carbon fiber, said mixture withstanding a temperature of 200"C or higher without deforming.

Other objects and features of the present invention will become apparent from the following description taken with reference to the accompanying drawings in which: Figure l is a vertical sectional view of a first embodiment of this invention; Figure 2 is a similar view of a second embodiment; and Figure 3 is a similar view of a third embodiment.

Referring to Fig. 1, the roll in accordance with the present invention has a roll core 1 and a tubular covering 2 of rubber or other elastic material covering a major part of the roll core.

In accordance with the present invention, the roll core should be made of at least one kind of synthetic resin, graphite as a packing agent, and glass fiber and/or carbon fiber as a reinforcing agent. The mixture should have such a heat resistance that it can withstand a temperature of 200"C or higher without deforming.

Synthetic resin may be either thermoplastic resin such as nylon resin and polyester resin or thermosetting resin such as epoxy resin, unsaturated polyester resin, diallylphthalate resin and phenol resin. These resins may be used singly or in combination.

The content of graphite should preferably be 30-40 parts by weight and that of glass fiber and/or carbon fiber be 60-70 parts by weight with respect to 100 parts by weight of synthetic resin.

The;mixture of synthetic resin, graphite and glass fiber and/or carbon fiber may be formed either into a cylindrical shape as in Fig. 1 by compression molding or into a tubular shape as in Figs. 2 and 3 by compression or extrusion molding. Or alternatively, the roll core may be formed into a tubular shape by spirally or helically winding a glass fiber filament or carbon fiber filament while impregnating it with a mixture of a thermosetting resin and graphite.

The covering 2 can be made of an elastic material such as rubber or soft vinyl chloride resin, depending upon the application. After having been mounted on the roll core, the covering 2 is press vulcanized against the roll core 1 by heating.

In case the roll core is formed in a tubular shape as shown in Figs. 2 and 3, a metal stub shaft 3 or 3' having a sufficient mechanical strength and good heat and chemical resistances should preferably be mounted on each end of the roll core 1 as by adhesion to improve the durability.

In accordance with the present invention, a roll core is provided which is lighter in weight and has good heat and chemical resistances. Since the mixture used can withstand a temperature of 200"C or higher, the vulcanization temperature can be high enough to assure secure adhesion of the covering to the roll core and to assure high chemical resistance. Also, vulcanization at high temperatures means shorter time required for vulcanization and higher productivity.

To further illustrate this invention, and not by way of limitation, the following examples are given. Unless otherwise stated, quantities are expressed as parts by weight.

Example 1 100 parts of diallylphthalate resin was mixed with 65 parts of glass fiber and 35 parts of graphite. The mixture was compression molded to form a roll core of a cylindrical shape. As shown in Fig. 1, a greater part of the outer periphery of the roll core 1 was covered by a covering 2 which comprises acrylonitrile rubber reinforced with carbon black, and the covering was press vulcanized against the roll core at 1 70 C for 20 minutes. The sizes of the roll thus produced were as follows: Roll core: 404 mm long, 20 mm dia.

Covering: 374 mm long, 25 mm dia.

The weight of the roll is shown in Table 1 in comparison with a control roll which is of the same size as the embodiment of this Example but comprises a roll core of stainless steel covered with a covering of acrylonitrile rubber.

Table 1 Roll of this Control roll invention Core weight 990 g 250 g Covering weight 80 g 80 g Total weight 1,070 g 330 g Weight index 100 30.8 The rolls of this Example were used for 3 months as film feed rolls at the development, fixing and washing units of an automatic film developing machine. As a result, no corrosion or other troubles were observed.

Example 2 100 parts of phenol resin was mixed with 65 parts of glass fiver and 35 parts of graphite. A tubular roll core 1' was formed by extrusion molding the mixture. A stepped shaft 3 of stainless steel was bonded to each end of the roll core, as shown in Fig. 2. The roll core with the stepped shafts was then covered with an elastic covering of acrylonitrile rubber reinforced with carbon black. The covering was press vulcanized against the roll core under the same conditions as in Example 1. The sizes of the rubber roll thus made were as follows: Roll core: 394 mm long, 20 mm dia.

Covering: 374 mm long, 25 mm dia.

Stepped shaft: large-diameter portion 1 5 mm long, 20 mm dia.

small-diameter portion 1 5 mm long, 12 mm dia.

The weight of the rubber roll made in this Example is shown in Table 2 in comparison with a control roll which is a rubber roll of the same structure as the embodiment of Example 1 and of the same size as the embodiment of Example 2.

Table 2 Roll of this Control roll invention Core weight 355 g 170 g Covering weight 80 g 80 g Total weight 435 g 250 g Weight index 100 57.5 The roll of Example 2 was used for 3 months as film feed rolls at the development, fixing and washing units of an automatic developing machine. After the 3-month use, no corrosion, damage or other trouble was observed.

Example 3 100 parts of epoxy resin was mixed with 65 parts of glass fiber and 35 parts of graphite. The mixture was compression molded to form a tubular roll core 1'. A stepped shaft of stainless steel was bonded to each end of the roll core as shown in Fig. 2. The roll core with the stepped shaft was covered by an elastic covering of soft acrylonitrile rubber having a JIS rubber hardness of 20 degrees (JIS is the abbreviation of Japanese Industrial Standard). The covering was press vulcanized under the same conditions as in Example 1.

The sizes of the roll thus made were as follows: Roll core: 510 mm long, 25 mm dia.

Covering: 450 mm long, 50 mm dia.

Stepped shaft: large-diameter portion 40 mm long, 19 mm dia.

small-diameter portion 40 mm long, 12 mm dia.

The weight of the rubber roll is shown in Table 3 in comparison with a control roll which has a roll core of soft steel (SS40) covered by an elastic covering of soft acrylonitrile rubber.

Table 3 Roll of this Control roll invention Core weight 1,219 g 514 g Covering weight 729 g 729 g Total weight 1,948 g 1,243 9 Weight index 100 63.8 The embodiment of Example 3 and the control roll were kept immersed in water having a pH of 4 to 6 for 3 months. Rust appeared on the surface of the control roll whereas no rust or corrosion was observed on the embodiment of this Example.

Example 4 Instead of diallylphthalate resin used in Example 1, nylon resin, polyester resin and unsaturated polyester resin were used to make three rolls similar to the embodiment of Example 1 under the same conditions. The weight of the rolls thus made is shown in Table 4 in comparison with a control roll which is the same as the control roll in the Example 1.

Table 4 Control Roll Roll Roll roll (1) (2) (3) Synthetic Nylon Polyester Unsaturated resin used resin resin polyester resin Core weight 990 g 240 9 250 9 265 g Covering weight 80 g 80 g 80 g 80 g Total weight 1,070 g 320 g 330 g 345 g Weight index 100 29.9 30.8 32.2 These rubber rolls were used for 3 months as film feed rolls in an automatic film developing machine. No undue changes such as corrosion were observed.

Example 5 One of epoxy resin, unsaturated polyester resin and diallylphthalate resin was mixed with graphite. While impregnating with the mixture, glass fiber filament or carbon fiber filament was wound into a tubular shape by filament winding. An elastic covering of rubber was then formed on the tubular roll core thus made and vulcanized by steam at 150"C for six hours. The roll thus made showed excellent quality with no appreciable deflection.

Claims

1. A roll having a roll core covered with a covering of an elastic material, characterized in that said roll core is made from a mixture comprising at least one kind of synthetic resin, graphite, and glass fiber and/or carbon fiber, said mixture withstanding a temperature of 200"C or higher without deforming.

2. A roll as claimed in claim 1 wherein said roll core is of a cylindrical shape.

3. A roll as claimed in claim 1 wherein said roll core is of a tubular shape and is provided with a metal shaft at each end thereof, said metal shaft having good heat and chemical resistances.

4. A roll having a roll core covered with a covering of an elastic material, characterized in that said roll core is made by winding glass fiber filament or carbon fiber filament while impregnating with a mixture of at least one kind of thermosetting resin and graphite.

5. A roll as claimed in claim 4 wherein said roll core is a tubular shape and is provided with a metal shaft at each end thereof, said metal shaft having good heat and chemical resistances.

6. A roll constructed substantially as hereinbefore described with reference to Fig. 1, 2 or 3 of the accompanying drawings.

7. A method of manufacturing a roll having a core covered with a covering of elastic material, substantially as hereinbefore described.