JPH0568330B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a method of lining the surface of a roll core metal, the inner or outer surface, or both inner and outer surfaces of a metal tube, etc. with ultra-high molecular weight polyethylene by compression molding. [Prior Art] The development of various industrial equipment has been remarkable in recent years, and resin linings for equipment parts play an extremely important role. Resin linings take advantage of the abrasion resistance, chemical resistance, corrosion resistance, etc. of resin, and are widely used in the steel industry, paper industry, textile industry, chemical industry, etc. Various resin linings, such as polyethylene, polyurethane, fluorine resin, nylon, and various rubbers, are used for applications that take advantage of their distinctive characteristics. On the other hand, with the recent development of the polymer industry, various functional synthetic resins have been developed, and among these, ultra-high molecular weight polyethylene has been developed to take advantage of its excellent properties such as abrasion resistance, impact resistance, and chemical resistance. Although its uses are expanding, this ultra-high molecular weight polyethylene has poor melt flowability, making it difficult to mold using normal extrusion or injection molding methods, so it is now molded using compression molding. . [Problems to be Solved by the Invention] Conventionally, when attempting to line ultra-high molecular weight polyethylene, for example, when attempting to apply resin lining to a roll core metal, the above-mentioned compression molding method was used to form a cylinder. We had no choice but to create a shaped resin molding, cut out its center by machining, and fit it onto the roll core metal, but this method involved many steps, resulting in poor productivity. Since the resin is not chemically bonded to the core metal, there are drawbacks such as poor durability. Furthermore, when lining a flat plate or the like in the form of a plate, a method was used in which a sheet formed in advance by compression molding was attached using screws or the like, which caused problems in productivity. [Means for Solving the Problems] In view of the problems of the prior art as described above, the present invention improves production by molding ultra-high molecular weight polyethylene directly onto the surface of the object to be lined using a compression molding method. This method was developed with the aim of providing a resin lining method with good properties and durability.When lining a metal body with ultra-high molecular weight polyethylene resin, if the metal body is not tubular, Insert into the outer mold corresponding to the outer shape,
When the metal body is tubular, a mold corresponding to its inner shape or outer shape or inner shape and outer shape is placed on the inside or outside or on both the inside and outside sides, and the resin powder or pellets are supplied into the gap between the mold and the metal body. The resin is compressed while being pressurized and heated from the inner or outer surface or both the inner and outer surfaces of the mold, and the heating temperature is maintained for a time necessary to melt the resin, thereby completely melting the resin and forming the metal body. It is characterized by being brought into close contact with. [Function] That is, in the method of the present invention, a mold corresponding to the outer shape or inner shape or the outer shape and inner shape of the metal body to which the ultra-high molecular weight polyethylene resin is to be applied is placed on the outside or inside of the metal body or on both the inside and outside sides of the metal body, The resin powder or pellets are supplied into the gap formed between the metal body and the mold, and the mold is heated from its outer surface, inner surface, or both inside and outside surfaces while pressurizing the resin, and the resin is melted to form the surface of the metal body. After adhering to the resin, the resin is cooled and the outer mold is removed to obtain a metal body lined with the resin. [Example] Next, as an example of implementing the method of the present invention, an example of manufacturing a resin lining roll will be described with reference to the drawings. In the figure, 1 is a roll core metal, 2 and 2a are shaft cores protruding from both sides thereof, and 3 is a medium size mounted on the shaft core 2, and its outer diameter is the same as the outer diameter of the roll core metal 1. Reference numeral 4 denotes an outer mold attached to the pedestal A, into which the roll core metal 1 is inserted with its shaft core 2a protruding from the bottom. Reference numeral 5 denotes a pressing member fixed to the tip of a piston rod 7 of a hydraulic cylinder 6. This pressing member 5 has a cylindrical shape, and is moved up and down in the gap between the roll core metal 1 and the outer mold 4 by driving the hydraulic cylinder 6. Then, the powder or pellets of ultra-high molecular weight polyethylene resin P supplied into the gap is pressurized. H is a heating device consisting of a high frequency inductor, and the outer mold 4
This is for heating and melting the resin P from the outside, and is movable up and down. An example of the present invention is implemented by the above device,
The process will be explained as follows. First, the medium size 3 is attached and fixed to the shaft core 2 of the roll core metal 1. Next, this is inserted into the outer mold 4, and the shaft core 2a
When it protrudes from the hole provided in the center of the bottom plate of the outer mold 4, an annular gap with a circular cross section is created between the middle mold 3 and the outer mold 4, so resin P is poured into this gap and the hydraulic cylinder 6 is driven. The resin P is pressurized by the pressing member 5, while the resin P is heated and melted from the outside of the outer mold 4 by the heating device H, and the heating temperature is maintained for a time necessary to melt the resin P, and the coil core metal When the resin P is melted and adhered to the entire length except for the shaft cores 2 and 2a of 1, stop heating and cool it down, and then
By removing the resin, a lining roll is obtained, and in order to complete the roll product with high precision, the outer surface of the lining resin may be subjected to appropriate machining such as lathe processing. Therefore, the medium mold 3 in the above device is necessary to compensate for the decrease in capacity due to the increase in density when the powder resin is turned into a molded body, and also serves as a guide for the pressing member 5. . For this purpose, it is necessary to determine the length according to the length and shape of the roll. Furthermore, it is not necessary to fill the resin in one go; if the amount of resin is insufficient in one filling, the supply and pressurization may be repeated several times. If ultrasonic vibration is used, the packing density will be high and efficiency will be high. In addition, in order to improve workability, the powder resin to be filled is made into a small intermediate molded body that has been compression molded in advance.
It may be manufactured by filling this intermediate molded body and compression molding it. In this case, the intermediate molded body does not need to be one in which the powder is completely melted and molded, but may be one in which the powder is simply compressed and solidified. In any case, since the density of the resin to be filled is high even before compression, the amount of push of the mold during molding is shortened.
This has a great advantage because the mold size can be short. On the other hand, heating does not need to be performed after the supply of resin and filling by pressurization is completed; in some cases, heating may be performed before filling the resin;
Heating may be performed while repeatedly applying pressure. In either case, a good molded product can be obtained if the temperature is maintained at an appropriate level. In addition, in order to improve productivity, the roll core metal 1 may be preheated, or if the roll core metal 1 is also heated by a method such as electrical heating, the resin melts faster and productivity is further improved. do. Furthermore, if the outer mold 4 is made of a non-magnetic material such as SUS, aluminum, PBC, or Cu, and an induction heating coil is placed on the outside of the outer mold 4 and heated by selecting an appropriate frequency, the roll core 1 and the outer mold can be heated. It is also possible to raise the temperature of 4 at the same time. In the method in the above embodiment, the apparatus is of a vertical type, in order to facilitate the removal of air bubbles during molding of the resin, but the apparatus can of course be implemented even if the apparatus is of a horizontal type. Further, an example of the manufacturing conditions for the lining roll in the above example is as follows. Resin (Hisex Million 340M, manufactured by Mitsui Petrochemical Industries, Ltd.) Pressure: 20Kg/cm2 or ^more Heating temperature: 180-220℃ Heating holding time
30 minutes or more (when the lining thickness is 10 to 20 mm) It is possible to manufacture resin-lined rolls as described above, but not only rolls that are relatively long, but also gears, cams, etc. It can be manufactured by lining it and then machining it. Furthermore, lining can be applied not only to the outside of the object to be lined, but also to the inner surface of a tubular object, for example. In this case, insert a suitable mold inside the body to be lined,
Lining may be performed in the same manner as above. Of course,
It is also possible to line the inner and outer surfaces of the tubular object at the same time, and it is also possible to line the entire outside of the object to be lined. Furthermore, if a primer is applied to the lined surface of the object to be lined in advance such as blasting, and then a primer is applied to provide adhesion between the resin and the object to be lined, the resin and the object to be lined will bond after lining. This is extremely convenient because the two adhere well and there is no risk of them becoming misaligned. In this case, the primer is preferably a modified polyethylene, an epoxy resin, a rubber adhesive, etc., and it is a great advantage of the present invention that it can be directly compression molded onto the lined object coated with the primer.
Further, in order to mechanically eliminate displacement of the lining resin, the lining surface of the object to be lined may be machined to create irregularities or the like. Incidentally, the roll core bar shown in the embodiments does not necessarily have to be cylindrical, and may have any shape such as a conical shape or a drum shape. In this case, if a mold is manufactured according to the shape of the metal core, construction can be carried out using the same steps as those described in the embodiments. The ultra-high molecular weight polyethylene used in the present invention is obtained by polymerizing ethylene into a linear chain.

〔Effect of the invention〕

The present invention is as described above, and according to the method of the present invention, it is possible to directly line the object to be lined with ultra-high molecular weight polyethylene, which has been considered difficult in the past, thereby simplifying the work process and saving labor. , productivity is improved and processing costs are significantly reduced compared to conventional methods.

[Brief explanation of the drawing]

The figure is a sectional view of an example of an apparatus for carrying out the method of the present invention. 1... Roll core metal, 3... Medium size, 4... Outer type,
5...Press member, H...Heating device, P...Ultra high molecular weight polyethylene resin.

Claims (1)

[Claims] 1. When lining a metal body with ultra-high molecular weight polyethylene resin, if the metal body is not tubular,
When the metal body is tubular, a mold corresponding to its inner shape or outer shape or inner shape and outer shape is placed on the inside or outside or both inside and outside, and the mold and the metal body are inserted into an outer mold corresponding to the outer shape. By supplying powder or pellets of the resin into the gap and compressing the resin while applying pressure, heating from the inner or outer surface or both the inner and outer surfaces of the mold and maintaining the heating temperature for a time necessary to melt the resin. A method for lining a metal body with an ultra-high molecular weight polyethylene resin, the method comprising completely melting the resin and bringing it into close contact with the metal body. 2. The method according to claim 1, wherein the resin supplied to the gap between the mold and the metal body is an intermediate molded body obtained by compression molding powdered resin in advance.