JPH0548739B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for manufacturing a rubber roll, particularly a rubber roll having a two-layer structure in which an inner layer made of sponge rubber and an outer layer made of solid rubber are laminated.

(Prior Art) Conventionally, conveyance or pressure rolls used in high temperature conditions, such as pressure rolls for electronic copying machines, have a structure in which a sponge rubber layer made of silicone rubber and a solid rubber layer are laminated inside and outside. something is known.

When manufacturing this type of rubber roll, as in Utility Model Application No. 59-39315, an unfoamed rubber sheet compounded with sponge rubber is wound around the roll core shaft to a predetermined thickness, and then A method is known in which an unvulcanized rubber sheet compounded with solid rubber is similarly wound around the outer periphery of the sheet, and then these are vulcanized and integrated under heat and pressure.

In addition, a sponge roll coated with sponge rubber in a cylindrical shape around the outer periphery of the roll core shaft is inserted into the mold.
A manufacturing method is also known in which a non-foaming cold-curing liquid silicone rubber is press-fitted onto the outer periphery of the sponge roll, and after the liquid silicone rubber is cured, the rubber roll is removed from the mold.

(Problems to be Solved by the Invention) However, in the former method, when the rubber sheet is wound around the cylinder shaft to cover it, it is difficult to form the inner and outer layers to have a uniform thickness over the entire circumference. In addition to being difficult, there were other problems that required a great deal of time and effort.

Furthermore, the latter method has the problem that air bubbles tend to enter between the sponge rubber layer and the solid rubber layer, often resulting in defective products.

(Means for Solving the Problems) The present invention has been made to solve the above problems, and therefore, the thickness of the inner and outer layers is uniform, the adhesion between the inner and outer layers is perfect, and the bonding between the inner and outer layers is perfect. The technical challenge is to provide a rubber roll with a two-layer structure that does not contain air bubbles.

In order to solve this technical problem, in the present invention, a metal core shaft whose surface is coated with an adhesive is first
An inner layer made of unvulcanized, unfoamed rubber is formed around the outer periphery of the metal core shaft by passing it through a crosshead die of a second extruder, and then the metal core shaft with the inner layer formed thereon is passed through a crosshead die of a second extruder. After forming an outer layer made of unvulcanized non-foamed rubber around the outer periphery of the inner layer by passing it through a head die, the outer layer is charged into a mold and heated to vulcanize and foam the inner layer. The technical means is to simultaneously perform vulcanization of the metal core shaft and the inner layer, and to vulcanize and bond the inner layer and the outer layer.

(Example) FIG. 1 shows the manufacturing process of a rubber roll according to the present invention. After the surface of the metal core shaft 1 is degreased and cleaned A, and an adhesive for silicone rubber is applied B, this metal core shaft 1 is The unfoamed silicone rubber 2 containing a foaming agent is extruded and coated onto the metal core shaft 1 by inserting it into the crosshead die of an extruder to form an inner layer C. Next, this metal core shaft 1 is inserted into a crosshead die of a second extruder, and unvulcanized, non-foamed silicone rubber 3 is extruded and coated on the inner layer to form an outer layer D, and this is then coated as an inner and outer layer. is charged into a cylindrical mold with a diameter larger than the laminated metal core shaft 1 and heated with an appropriate external heat source such as hot air to vulcanize and foam the unfoamed rubber layer 2 and the unvulcanized non-foamed rubber layer 3. Vulcanization is performed at the same time to form a roll shaped along the inner peripheral surface of the mold. At this time, the foaming agent contained in the unfoamed rubber layer 2 decomposes, this rubber layer 2 expands, and the void in the mold formed in the sponge rubber layer is filled, and at the same time, this rubber Due to the foaming pressure of the layer 2, the unvulcanized non-foamed rubber layer 3 is pressed against the inner circumferential surface of the mold, and is vulcanized into a solid rubber layer by this pressure.

Thereafter, the roll is demolded from the mold F, and a rubber roll is obtained in which a silicone rubber sponge layer 2 and a silicone rubber solid layer 3 are formed in two layers around the outer periphery of the metal core shaft 1, as shown in FIG. .

In the above embodiment, the inner and outer layers are formed of silicone rubber, but they may be formed of other known rubbers.

(Operations and Effects of the Invention) As explained above, in the present invention, both the inner and outer layers formed on the outer periphery of the metal core shaft are formed by extrusion coating using an extruder, so the thickness of the inner and outer layers is uniform. Since it is easy to process, and there are no air bubbles between the inner and outer layers, a high-quality two-layer rubber roll can be obtained.

In addition, after forming the unvulcanized inner and outer layers on the metal core shaft, they are heated in the mold, making it possible to simultaneously perform foam molding of the inner layer and vulcanization molding of the outer layer in one process. In addition to being highly efficient in manufacturing, the inner layer, metal core shaft, and outer layer are vulcanized and bonded to each other, so there is no peeling between the metal core shaft and the inner layer, and there is no peeling between the inner and outer layers, resulting in excellent durability.

[Brief explanation of the drawing]

FIG. 1 is a manufacturing process diagram of a rubber roll according to the present invention, and FIG. 2 is a sectional view of a rubber roll manufactured according to the present invention. 1...Metal core shaft, 2...Sponge rubber, 3...
Solid rubber, A... Degreasing and cleaning, B... Adhesive application, C... Inner layer formation, D... Outer layer formation, E... Mold charging and heating, F... Mold removal.

Claims (1)

[Claims] 1 The metal core shaft with adhesive applied to its surface is
An inner layer made of unfoamed rubber is formed around the outer periphery of the metal core shaft by passing it through the crosshead die of a second extruder, and then the metal core shaft with the inner layer formed thereon is passed through the crosshead die of a second extruder. An outer layer made of unvulcanized non-foamed rubber is formed around the outer periphery of the inner layer by passing the rubber through the inner layer, and then this is charged into a mold and heated to vulcanize and foam the inner layer and vulcanize the outer layer. A method for manufacturing a rubber roll having a two-layer structure of a foamed rubber layer and a non-foamed rubber layer, characterized in that the metal core shaft, the inner layer, the outer layer, and the inner layer are vulcanized and bonded.