FI59217C - FOER FARING FOR FRAMSTAELLNING AV EN MED ETT POLYURETANGUMMISKIKT BELAGD VALS - Google Patents

Description

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Yamauchi Rubber Industry Co., Ltd., No. Patents och raglataratyralaan '' AnsBIcu uthgd och utUkrlfMn puMIcarad 31.03.81 (32) (33) (31) Yamauchi Rubber Industry Co., Ltd., no. 7 »Shodaitajika 2-chome, Hirakata-shi, Osaka, Japan-Japan (JP) (72) Yasuo Fukuyama, Hirakata-shi, Osaka, Yosuke Okada, Hirakata-shi,

Osaka, Japan-Japan (JP) (7I +) Oy Kolster Ab (5U) Method for the production of a roll coated with a layer of polyurethane rubber - Förfarande för framställning av en med ett polyuretangummi-skikt belagd or

The invention relates to a method of manufacturing a roll coated with a polyurethane rubber layer, wherein a rigid metal core with grooves is rotated to wrap an impregnated thread around the core into a uniform fiber layer, after which a polyurethane rubber layer is cast on the fiber layer and finally ground.

Polyurethane rubber coated rolls are used in the paper, textile, iron and steel industries, etc. Known roll cores, especially large roll cores made almost exclusively of cast iron for cost reasons, are known to have certain disadvantages, such as brittleness in the material and small holes in the surface. thereby reducing the bond strength between the roll and the polyurethane rubber layer.

Non-cast iron cores are also used, such as stainless steel or bronze or aluminum roller cores. These roll cores have a higher strength and are otherwise better than cast iron cores and do not have small holes in the surface. However, due to their high chemical resistance, they show poor adhesion to the polyurethane rubber layer. Polyurethane rubber has high strength as well as wear and tear resistance. The strength is usually higher than the strength of the bond between the roll core made of cast iron, stainless steel, bronze, aluminum, etc., and the polyurethane rubber, and when such a roll coated with a polyurethane rubber layer operates under high load and high speed,

In order to eliminate the causes of these disadvantages, e.g. the following attempts: (1) A roll core with a rough surface is used.

(2) A hard rubber surface is formed on the roll core.

The above method (1) ended in failure because the rough surface tended to increase the formation of foam in the binder layer and caused the layer to tear.

Method (2) also ended in failure because, when casting polyurethane rubber on a hard rubber layer, it was found to be extremely difficult to use mold casting to form a polyurethane layer having a strength corresponding to the hard rubber layer. In addition, the large difference between the strengths of the two layers makes it impossible to bond the hard rubber layer to the polyurethane rubber layer so that the polyurethane rubber layer does not tear off under high load and high rotational speed.

As stated above, both of the above methods (1) and (2) have been found to be invalid in an attempt to achieve successful results.

It is an object of the present invention to provide a method of making an improved polyurethane rubber coated roll that is free of peeling of the cover layer from the roll core under high load and high rotational speed.

It is a further object to provide a method by which a polyurethane rubber roll can be produced at a lower cost by saving the thickness of the polyurethane rubber, since the cost increases with the thickness of the fiber layer.

It is a feature of the invention that preferably the filament of fiberglass is impregnated with a thermosetting resin, and that the 3,592,17 filament is made by rotating the core into circumferentially extending grooves to form a flat, strong substrate for attaching a rubber layer thereto. It is also advantageous to add a binder to the fiber layer before casting the rubber layer on. In addition, the thread is wound on the core under tension.

The invention is illustrated by the following drawing, in which Figure 1 is a cross-sectional view of how a strand is fastened by winding around a roll core, Figure 2 is a vertical section of a roll and mold, Figure 3 is a longitudinal section of a roll, and Figure H is a partial cross-section of a roll. made of metals such as cast iron, stainless steel, bronze, aluminum, etc. The roller core 1 rotates to receive in a winding a thread 4, e.g. fiberglass, nylon, polyester, etc., the fibers of which are completely impregnated with thermosetting resins such as epoxy, diallyl phthalate, etc. by dipping the filament in solution 5. A filament layer 2 of the desired thickness is thus formed around the core 1. The roll is then placed before or after the thermosetting resin has hardened and possibly finished, and possibly with a binder 6 applied to the surface, in place in the mold 7 according to Figure 2. The polyurethane resin is then poured into a mold so that a polyurethane layer 3 is formed around the roll.

The following examples further explain how the roll of the invention is made.

Example 1

The polyurethane rubber coated roll was made of the following materials:

Cast iron ball core: 2 meters long and 600 mm in diameter, (generally recommended length / diameter ratio less than 5).

_c Distortion test 1 x 10, maximum.

Groove cut around the circumference at 2.5 mm intervals.

Thread: A glass thread made of 9 μg of glass fiber, the glass fiber having been pre-treated by Volan impregnation.

* 5921 7

Thermosetting resin:

Epoxy resin (mixed solution with 100 parts of Shell Oil Co. "Epikote® 815" and 10 parts of triethylenetetramine).

As shown in Fig. 1, a thread 4 impregnated with epoxy resin is wound on the roll core 1, wherein the ratio of the weight of the thread to the weight of the resin was 2: 1. The winding is carried out under a pressure of 10 kp until the fiber layer 2 reaches a thickness of 4 mm. The roll with the filament layer was then placed in a casting mold designed to have a 25 mm thick layer of polyurethane rubber on top of the filament layer after casting. A polyurethane elastomer casting solution, an antifoam solution containing 100 parts of Dupont's "Adiprene® L-100" and 12 parts of methylene bis-O-chloroaniline is poured into the space between the mold and the roll, and after the casting has been cured by drying for 10 hours at 100 ° C, it was cooled to normal temperature and removed from the mold, and the surface was smoothed by tacking until the polyurethane rubber layer 3 of the finished roll was 20 mm thick.

The polyurethane rubber coated roll was found to withstand use at normal temperatures under a load of 240 kg / cm and a rotational speed of 100 rpm. A polyurethane rubber coated normal roll in which the polyurethane rubber layer adheres directly to the roll core with an isocyanate-type binder without a resin-impregnated filament layer showed peeling of the rubber layer when used at a load of 160 kg / cm under all other conditions the same as above.

Example 2

The polyurethane rubber coated roll was made of the following materials:

Cast iron roller core: 2 meters long, diameter 300 mm.

-6 -4

The maximum range of the bending test is 1 x 10 ... 1 x 10

Thread pitch of the circumferential screw groove 1 ... 6 mm.

Thread: Glass thread manufactured by Nitto Bo, Ltd., made of fiberglass "GYR-60-FWE".

Thermosetting resin:

Epoxy resin Cseos solution with 100 parts "Araldite GY

2 50 ", 80 parts of anhydrophthalic anhydride and 2 parts of a tertiary accelerator ..., 1 amine 1 BDKA, (Benzyldimethylamine).

5,59217

A casting 4 impregnated with resin 5 is wound on a cast iron core prepared as mentioned above, the weight ratios of the strand and the resin being 40:60 to 80:20, the winding direction being inclined at 50 °. The winding direction is changed alternately layer by layer, and the winding is performed under a pressure of 10 kp. Rewinding was continued until the filament layer reached a thickness of 2 ... 5 mm. The fiber layer of the roll was then cured by a heating process for 4 hours at 100 ° C, for 5 hours at 150 ° C, i.e. for a total of 9 hours, and then the fiber layer 2 was smoothed with lathes to obtain a smooth surface. The semi-finished roll was then set up and an isocyanate-based binder 6 was applied to the surface and placed in a mold. The space was filled with a polyurethane elastomer in the same manner as in Example 1 and cured by a heating process for 5 hours at 100 ° C. The surface was finished as described in Example 1. No cracks of any kind were observed in the polyurethane rubber roll, which tend to occur in the resin-saturated fiber layer due to the distortion of the roll core.

Example 3

The polyurethane rubber coated roll was made of the following materials:

Aluminum roller core: 2 meters long, 40 mm thick and 600 mm outside diameter.

Thread: Polyurethane terephthalate thread, 20 denier.

Thermosetting resin:

Epoxy resin, in the same manner as used in Example 1.

The filament impregnated with resin in a weight ratio of filament: resin = 1: 1 was wound on an aluminum core while applying a pressure of 10 kp to the circumference. Winding was continued until the filament layer reached a thickness of 3 mm, and the resin-impregnated filament layer was cured by leaving it at normal temperature for 2 hours. This was followed by the molding process described in Example 2. The polyurethane rubber coated roll was found to be free of any tearing of the rubber layer from the aluminum roll core.

Example 4

The polyurethane rubber coated roll was formed from the following materials; 6,59217

Stainless steel or bronze roll core: Suction roll for paper machine, 3.5 m long, 30 mm thick and 500 mm outside diameter, with 90 000 holes, each 3 mm in diameter, perforated throughout and 1 mm deep grooves cut 3 mm apart.

Thread: Fiberglass tape, "ECL-9230-65", made of non-alkali type fiberglass with a thickness of 0.23 mm and a width of 65 mm, made of Nitto Bo, and fiberglass "GYR-60-FWE", made of Nitto Bo formulation.

Thermosetting resin:

Epoxy resin (mixture solution with 100 parts "Araldite GY52" and 23 parts "Araldite HY974").

The above two types of filaments, namely fiberglass tape i + 'and fiberglass 4 ", previously impregnated with resin at a weight ratio of 40:60 to 80:20 of the filament and resin, are alternately wound in layers on the core 1 under a pressure of 10 kp until each layer reaches 11 mm thick The roll was left to cure at normal temperature for 6 hours.

Thereafter, the surface of the filament layer 2 was finished by rubbing and mold casting was performed as described in Example 2 to obtain a polyurethane rubber coated roll (Fig. 4).

With this example, it was found that a suction roll of a paper machine with numerous small holes can be used as a roll core in the manufacture of a polyurethane rubber roll, and that the need for a new roll core can be specifically disregarded for this purpose.