JPH0667602B2 - Method and apparatus for manufacturing ultra high molecular weight polyethylene lining roll - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing an ultrahigh molecular weight polyethylene lining roll used for various rolls such as a compression roll, a transport roll, a table roll, a carrier roll, and the production thereof. The present invention relates to an apparatus, and more particularly to a method and an apparatus for continuously and rapidly producing the above ultrahigh molecular weight polyethylene lining roll.

(Prior Art) A roll whose outside is lined with resin has flanges at both ends of a metal rod-shaped body or a metal tubular body having strength,
The resin cylindrical body is press-fitted onto the metal roll base body provided with a shaft by this, or is fitted and fixed by a method such as shrink fitting,
Or it was manufactured by giving a grinding finish.

Further, as disclosed in JP-A-53-39362, a heated resin tubular body is arranged outside a metal base roll, and a liquid resin such as urethane is placed between the metal base and the resin tubular body. A method of injecting, curing and fixing is also proposed.

So-called general-purpose resins such as poiacetal, parcarbonate and nylon are used as the resin used for such a tubular body.

Furthermore, the present inventors have already extruded and once cooled the ultrahigh molecular weight polyethylene tubular body as a method for producing an ultrahigh molecular weight polyethylene lining roll to reheat it to a crystallization temperature or higher to thermally expand it, so that the inner diameter is a roll base. We proposed a method in which the roll is fitted in a state where it is larger than the outside diameter of the body, and then cooled and shrunk to fix it to the roll substrate.

(Problems to be Solved by the Invention) According to the conventional shrink fitting and press fitting methods, since the resins have their own elasticity and coefficient of thermal expansion, it is necessary to improve the surface smoothness and the dimensional accuracy of the metal substrate. On the other hand, in order to improve the finishing accuracy of the inner surface of the resin tubular body that is press-fitted or shrink-fitted, it takes time to process it. Besides, shrink fitting,
At the time of press fitting, it is impossible to fit the resin cylindrical body unless the shrinkage fitting margin and the press fitting margin of the resin cylindrical body are taken into consideration in consideration of the correlation between the roll diameter of the metal substrate and the resin outer cylinder wall thickness. ,
In addition, there is a defect that the resin is cracked or damaged after fitting.

Further, the method of placing a heated resin tubular body on the outside of the metal base roll, injecting a liquid resin such as urethane between the metal base and the resin tubular body, and curing and fixing the resin takes time and effort to manufacture. There was a flaw. Further, when a general-purpose resin is used as the resin for the tubular body, there is a defect in any of impact resistance, abrasion resistance and chemical resistance.

Further, it has been clarified that the method for producing an ultra-high molecular weight polyethylene lining roll proposed by the present inventors requires an excessive heating device when the roll is long, resulting in a very large heat loss.

The present invention is to improve such a point, and does not require processing for improving the smoothness and finish dimensional accuracy of the outer surface of the roll substrate, and has impact resistance, abrasion resistance, chemical resistance and durability. (EN) A method and an apparatus for continuously and rapidly producing a roll lined with ultra-high molecular weight polyethylene having an excellent outer surface and with a small heat loss.

(Means for Solving Problems) That is, the first aspect of the present invention provides an ultrahigh molecular weight polyethylene tubular body extruded by a ram extruder at a crystallization temperature or higher.
While keeping the temperature at ~ 200 ° C, directly and continuously fit the roll base fixed on the concentric line of this tubular body to cover the roll base, cut the tubular body, and then cool the tubular body. A method for producing an ultra-high molecular weight polyethylene lining roll, which is characterized in that it is then contracted.

A second aspect of the present invention is a tubular formable ram extruder in which a movable ram having a mandrel protruding from the inside of the extrusion cylinder is inserted, and a cover removable from the cylinder outlet of the ram extruder. A heat-insulating hood, which is connected through a member to keep a molded tubular body warm, and a movable roll-base fixing device having a roll-base installed in the heat-insulating hood fixed at one end. It is an apparatus for producing an ultrahigh molecular weight polyethylene lining roll, which is characterized in that

Hereinafter, specific embodiments of the manufacturing apparatus of the present invention will be described in detail.

FIG. 1 is an overall view of the manufacturing apparatus of the present invention, in which (1)
Is the ram extruder used in the present invention. This ram extruder (1) is of the commonly known flanger type. (2) is a cylindrical cylinder, a raw material supply part (3) is installed near the rear end of the cylinder, and a plurality of heating devices (4a) (4b) are mounted on the surface of this cylinder. A ram (6) that reciprocates by a predetermined movement width is inserted by a hydraulic device (5) installed from the rear end side of the cylindrical cylinder (2) to the rear end portion, and a rod-shaped mandrel (7) is inserted at the tip of the ram. Is attached.

The dimensions of the extruded tubular body (8) are regulated by the inner diameter of the cylinder (2) and the outer diameter of the rod-shaped mandrel (7). The extrusion speed during extrusion molding is the inner diameter of the cylinder (2) of the ram extrusion device and the rod-shaped mandrel (7).
It is necessary to properly adjust the outer diameter, length and temperature of the heating device (4a) (4b), and in the case of the present invention, the temperature of the heating device of the cylinder is 150 to 300 ° C, preferably 180 to 250 ° C.
Is set to. If the temperature is 300 ° C or higher, the ultrahigh molecular weight polyethylene deteriorates due to thermal decomposition, and if the temperature is 150 ° C or lower, the extrusion pressure becomes excessive, and in an extreme case, extrusion molding becomes impossible, which is not preferable.

Further, a portion (9) in the drawing is a cover member for cutting the molded tubular body, and is a connecting flange (1
The cover member (1) in which the cylinder (2) outlet of the ram extruder and the heat insulating hood (13) are made of cylindrical heat-resistant canvas
1) is fixed through.

The part (13) in the figure is a heat-insulating hood portion for fitting the molded tubular body (8) into the roll base (14), and the extruded tubular body (8) is heated to a predetermined temperature of 140 to 200 ° C. It is installed to keep warm, and an extruded cylindrical holder (16) is attached inside, and an outlet (17) consisting of an openable lid and the like is attached to the end.

Further, a portion (18) in the figure is a roll base fixing tool for fixing the roll base (14) which has entered the heat insulating hood (13). The projecting rod (19) of the roll base fixture is fitted with the roll base (14), and one end thereof is cantilevered and fixed to a movable fixed carriage (21) having a car (20). During the forming, the fixed carriage (21) is fixed to the floor surface by the fixing pin (22) which is easily removable, and the connecting flange (10) is removed when the tubular body (8) is formed to the full length of the roll base. The ultra-high-molecular-weight polyethylene tubular body is cut at (A), and the roll that has been molded while being fixed to the fixed carriage is taken out in the extrusion direction, that is, outside the heat retaining hood (13) and immediately inserted into the next. The roll base is replaced and returned to its original state, but it is possible to continuously form the roll base during replacement.

An ultra high molecular weight polyethylene lining roll is manufactured by using the above-mentioned apparatus, and the process is as follows.

(A) The temperature of the cylinder (2) of the ram extruder is set to be equal to or higher than the crystallization temperature of the ultrahigh molecular weight polyethylene, that is, 150 to 300 ° C., and the tubular body (8) of the ultrahigh molecular weight polyethylene is extruded.

(B) The tubular body (8) is introduced into the heat insulation hood (13) adjusted to 140 to 200 ° C. and directly and continuously to the roll base (14) fixed in advance in the heat insulation hood (13). Be inserted. In this case, the inner diameter of the cylindrical body (8) is 0.1 to 6% of the outer diameter of the roll base (14) in the temperature range of 140 to 200 ° C.
It is large. The roll base (14) is a cylinder (2).
It is fixed on the concentric line with.

(C) When the tubular body (8) covers the entire length of the roll base (14), the cover member (9) is opened, and the tubular body (8) is cut at this position.

(D) Immediately thereafter, the outlet of the heat retaining hood (13) is opened, the tubular body (8) is moved in the extrusion direction of the tubular body, and is taken out from the heat retaining hood (13) at 50 ° C. or lower for 3 hours. When it is cooled as described above, it firmly adheres to the roll base (14). Also,
The cooling condition is not limited to this, and water cooling is also possible.

When the tubular body (8) is taken out from the heat insulating hood, the roll base (14) is removed from the roll base fixing tool (18). The following roll base (14) is fixed to the roll base fixing tool (18) and is installed again in the heat insulating hood (13). The tubular body (8) is continuously extrusion-molded even during this roll base replacement operation, so that continuous molding is possible.

The ultra-high molecular weight polyethylene referred to here is a general-purpose polyethylene having a molecular weight of about 60 to 300,000 by the light scattering method and about 2 to 100,000 by the viscosity method, while 3 million or more by the light scattering method and 100 by the viscosity method
It is extremely suitable for use on the outer surface of rolls, as it shows a very large value of more than 10,000 and has superior impact resistance, abrasion resistance and crack resistance compared to general-purpose polyethylene and other plastics. is there.

In addition, the above-mentioned ultra-high molecular weight polyethylene has an extremely large molecular weight, and when heated at a crystallization temperature (crystallization melting temperature) of 135 to 138 ° C or higher and 200 ° C or lower, it has a property similar to that of a crosslinked resin. Since it does not flow and exhibits rubber-like elasticity, even if the tubular body extruded by a ram extruder is kept at a temperature above the crystallization temperature, its shape hardly changes.

Further, since ultra-high molecular weight polyethylene having a crystallization temperature or higher has a property of shrinking by 3 to 6% when cooled to room temperature, it can be easily fitted into the roll base without sufficiently improving the finish dimensional accuracy of the outer surface of the roll base. Is.

In addition, the ultra-high molecular weight polyethylene tubular body has a property of shrinking when cooled, so that it strongly adheres to the roll substrate. If the outer periphery of the finished roll lacks dimensional accuracy or smoothness, the outer peripheral surface may be cut.

The ultra-high-molecular-weight polyethylene tubular body referred to herein may be made of ultra-high-molecular-weight polyethylene that has been crosslinked with an organic peroxide or modified by adding a filler or the like.

Further, the roll base body referred to here is a rod-shaped or tubular body, and flanges are attached to both ends of a strong metallic tubular body,
It is a metal roll formed by forming a shaft on this.

Next, the production method of the present invention will be described in detail with reference to Examples.
It goes without saying that the present invention is not limited to this.

(Example) Inner diameter φ145m whose outer circumference was temperature-controlled to 200 ° C with an electric heater
A horizontal ram extruder (shown in FIG. 1) equipped with a cylinder with a heating section length of 1000 mm and a mandrel with an outer diameter of φ117 mm (shown in FIG. 1) was equipped with a roll base holder and the outer periphery was heated by an electric heater. A temperature-maintaining hood having an inner diameter of 300 mm and a length of 2000 mm in which the internal temperature was kept at 150 ± 10 ° C was connected by a tubular garam canvas. As a roll base, an iron cylinder with a length of 1800 mm and an outer diameter of φ115 mm with shafts attached to the inner diameter of both ends was used. The fixed carriage was fixed to the floor with a fixing pin that was easy to remove.

The cylindrical body of ultra-high molecular weight polyethylene powder (Hostalen GUR # 415 manufactured by Hoechst Co.) extruded by the above apparatus had a resin surface temperature of 160 ± 5 ° C. at an exit of the extruder and an outer diameter of φ142 mm ±.
The size was 1 mm and the inner diameter was 117 ± 1 mm, and there was almost no dimensional change in the thermal hood. When the extruded ultra-high molecular weight polyethylene tubular body is fit-molded to the entire length of the roll base,
The cover member was opened and the tubular body was cut. The roll, which had been molded in the state of being fixed to the fixed carriage, was taken out of the heat-insulating hood and immediately replaced with the roll substrate to be molded next. Extrusion molding continued during this roll substrate replacement work, and although the ultrahigh molecular weight polyethylene tubular body reached the inside of the heat retaining hood, the roll substrate could be replaced without any trouble.

The ultra-high-molecular-weight polyethylene tubular body on the outer periphery of the roll that has been molded is not fixed to the roll base after being taken out from the heat-insulating hood, so it is moved to a predetermined position on the roll base and then left to cool at room temperature for 3 hours or more. By doing so, it was contracted and fixed.

After the line-forming roll is finished, the outer diameter φ135mm is cut into both ends and the base length for finish processing, and the shafts are attached to the inner diameters of both ends through the shaft bearings to apply it to the steel plate conveying roll. Was strongly adhered to the substrate and did not move, and was about three times as durable as the nylon lining roll. In addition, in the above example, the extrusion molding speed of the ultra-high molecular weight polyethylene tubular body was 1.2 m /
It was hr, and the lining could be formed at a rate of one in about 95 minutes.

(Comparative Example) Using a ram extruder without a heat insulation hood, an ultrahigh molecular weight polyethylene tubular body was continuously extruded. This tubular body was once cooled to near room temperature and then cut into a length of 1820 mm. This ultra high molecular weight polyethylene cylinder has an outer diameter φ
The dimensions are 141 mm and inner diameter φ113 mm, and it was heated above the crystallization temperature to fit into the roll substrate.
It was necessary to reheat in a 0 ° C hot air oven for 30 minutes or longer. When the roll was long, an excessive hot air oven was required, which was inefficient in terms of energy.

(Effect) As described above, the manufacturing method of the present invention omits the step of cooling and reheating the extruded ultrahigh molecular weight polyethylene tubular body. Therefore, the time required from the molding of the ultra-high molecular weight polyethylene tubular body to the lining molding is shortened, there is no heat loss due to reheating, and further processing is required to improve the smoothness of the outer surface of the roll substrate and the finishing dimensional accuracy. And has excellent impact resistance, abrasion resistance, chemical resistance and durability, and the lining material on the outer circumference of the roll strongly adheres to the roll base and has an excellent outer surface that does not move. It has the effect of being able to produce molecular weight polyethylene lining rolls.

Further, in the manufacturing apparatus of the present invention, since the heat insulating hood is connected to the ram extruder through the removable cover member, and the roll base fixing tool for fixing the roll base is arranged in the heat insulating hood, It has an excellent effect that a high molecular weight polyethylene lining roll can be continuously manufactured.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of an apparatus for producing an ultrahigh molecular weight polyethylene lining roll according to the present invention. (1) …… ram extruder (2) …… cylindrical cylinder (8) …… ultra high molecular weight polyethylene tubular body (13) …… heat insulation hood (14) …… roll base (18) …… roll base fixing Ingredient

Claims (3)

[Claims] 1. An ultrahigh molecular weight polyethylene tubular body extruded at a crystallization temperature or higher by a ram extruder,
While keeping the temperature at 0 ° C., the roll base fixed on the concentric line with the tubular body was directly and continuously fitted to cover the roll base, and then the tubular body was cut, and then the tubular body was cooled. A method for producing an ultra-high molecular weight polyethylene lining roll, which comprises shrinking. 2. A patent characterized in that the inner diameter of the ultrahigh molecular weight polyethylene tubular body extruded by a ram extruder is 0.1 to 6% larger than the outer diameter of the roll substrate in the temperature range of 140 to 200 ° C. The method for producing an ultrahigh molecular weight polyethylene lining roll according to claim 1. 3. A ram extruder in which a movable ram having a mandrel projecting from the end is inserted into the extruding cylinder.
A heat retaining hood, which is connected to the cylinder outlet of the ram extruder via a removable cover member and retains heat of the molded cylindrical body, and a roll base installed in the heat retaining hood is fixed at one end. An apparatus for producing an ultra-high molecular weight polyethylene lining roll, characterized in that it comprises a movable roll base fixture.