JPS6340644B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a cladding tube with high roundness.

Recently, water supply and drainage pipes have been proposed in which the outer circumferential surface of a synthetic resin pipe such as a hard vinyl chloride pipe is coated with a fire-resistant inorganic material, or the outer circumferential surface of a metal pipe is coated with a similar coating to provide dew-proofing and soundproofing properties. The former is easy to cut, glue, and lathe, and not only has performance such as preventing condensation, but also has fire resistance that prevents the fire from penetrating and spreading to the upper floor or adjacent room in the event of a fire. In the latter case, it has the functions of preventing rust, preventing surface condensation, and preventing noise when water supply and drainage water is flowing, so it can be used to prevent bare water supply and drainage pipes such as conventional cast iron pipes and hard PVC pipes. It is starting to be used instead of.

One of the manufacturing methods for this coated tube body is to apply a mixture of hydraulic inorganic material, etc. and water to a certain thickness on a cloth made of organic fibers or mineral fibers, such as cloth or pine, to form various types of tubes. A method of wrapping it around the body has been proposed. (For example, patent application 1970-1970)
No.) The method according to the present invention requires large-scale equipment such as manufacturing asbestos pipes from sheets using the conventional papermaking method, and the selection range of the type and length of the fiber reinforcing material is narrowly limited. On the other hand, relatively simple manufacturing equipment is required, and reinforcing fibers are hardly required other than continuous fabrics such as cloth or matte.
Even if other substances such as thickeners, aggregates, etc. are used in combination, there is an advantage that the range of selection is wide.

Other possible methods for manufacturing the cladding include extrusion coating, casting, and injection coating, but the manufacturing cost of the mold is high, and in addition, inorganic materials such as hydraulic ones have a slow curing speed. Since it is slow, a large amount or long formwork is required, resulting in low formwork productivity as in the case of irregularly shaped pipe joints, and it is industrially impractical as a method for manufacturing straight pipes.

On the other hand, in the above-mentioned method of wrapping a cloth-like material made by adhering a water-kneaded material containing a hydraulic inorganic material to a certain thickness around the outer periphery of a synthetic resin pipe, a continuous cloth-like material such as cloth or mat is used. Therefore, if organic fibers are used, if the amount exceeds a certain level, the fire resistance of the cladding will decrease, and lightweight or coarse aggregate is often used to reduce weight or increase bulk. Therefore, the coating thickness has to be much thicker when compared with that of the papermaking method, and the total layer thickness will inevitably become too large unless the number of layers to be wound is reduced.

As a result, when the number of layers is small, it may be possible to complete the specified covering by just winding 2 to 3 layers, but in this case, the end of the winding will protrude, and if it is commercialized in this state, it will cause problems at the pipe joint part. In addition, the roundness of the cladding tube body becomes a problem because the appearance is not good. That is, poor roundness not only damages the aesthetic appearance of the product, but also impairs compatibility with support fittings and joint fittings during piping construction.

A finishing method that can be easily considered to eliminate the protrusion at the end of the winding is to evenly press the uncured cladding tube from the outside to smooth out the end of the winding and make it uniform. However, in reality, with this method, the uncured coating material extruded from the end of the winding may not be distributed smoothly on the surface of the cladding tube, may adhere to the surface of the pressure roller, or may fall onto the floor and make a mess. This results in a large amount of expensive covering material being disposed of as waste, and although the end portion of the winding has been improved to some extent, the overall roundness is not sufficient as described above, and there remains an economical problem.

An object of the present invention is to improve the problems of the above-mentioned method for manufacturing a cladding tube body, and to provide an economically advantageous method for manufacturing a cladding tube with high roundness.

More specifically, the object of the present invention is to wrap a cloth-like body such as cloth or mat coated with a water-kneaded material containing a hydraulic inorganic material as a main component around the outer peripheral surface of a tubular body, with the water-kneaded material inside. Even when the number of coating layers to be wrapped is relatively small, such as 2 to 3 layers, in the manufacturing method of the cladding pipe body, the roundness is still high and there is no problem with the inner diameter of the support fittings or joint fittings during piping. An object of the present invention is to provide a method for manufacturing a coated tube body.

Another object of the present invention is to ensure the minimum coating thickness necessary for fire resistance by making the coating thickness uniform over the entire circumference, and to eliminate excess coating to reduce and effectively utilize materials used and to improve the efficiency of the coating tube body. It is an object of the present invention to provide a method for manufacturing a cladding tube body that is lightweight.

Hereinafter, the contents of the present invention will be explained with reference to the accompanying drawings.

FIG. 1 shows a perspective view of a cladding body A produced in the first step in the method for manufacturing a cladding body of the present invention.

FIG. 1 shows a typical example of a cloth or mat made of organic fibers or mineral fibers, in which a cloth 2a made of organic fibers is used.

In the drawing, 1 is a hard vinyl chloride resin pipe,
2a is a cloth-like material made of vinylon, cotton, etc., and 2b is a water-kneaded material whose main component is a hydraulic inorganic material.The cloth-like material 2a coated with the water-kneaded material 2b is wound approximately two times, and then further coated. Cloth-like body 2a at the tip that is not
(e) continues. FIG. 2 is a cross-sectional view of this, and as can be seen from the drawing, at the end of the winding, a portion 2a(e) of mere cloth without the water kneaded material 2b is wound. At this point, the water-kneaded material 2b is lifted and protrudes at the winding start portion 2b(s) and winding end portion 2b(e), and is not a perfect circle as a whole.

It should be noted that the water-kneaded material applied above rarely adheres only to the surface of the fabric, and usually partially penetrates into the interior thereof. Examples of hydraulic inorganic materials used here include gypsum, Portland cement, slab cement, silica cement, flyash cement, alumina cement, and high sulfate cement (such as jet cement).
Various siliceous raw materials may be added to these cements as necessary. In addition, the above-mentioned hydraulic inorganic materials include asbestos, rock wool, glass fiber, wood wool, synthetic fiber, natural fiber, copper wire, steel fiber, mica, perlite, etc. for the purpose of reinforcement, improved fire resistance, weight reduction, and increase in weight. , calcined vermiculite, volcanic rock, aluminum hydroxide, calcium carbonate, calcium silicate, etc. can be added to further improve various performances. It is also possible to use various swelling admixtures, fluidity imparting agents, viscosity imparting agents, etc. in combination.

Examples of the organic fibers or mineral fibers constituting the cloth-like body used in the present invention include the following. Cotton, hemp, pulp, various protein fibers,
Various synthetic fibers, rock wool, slag wool, glass fibers, various ceramic fibers, carbon fibers, etc., and the cloth-like material such as cloth or mat in the present invention are aggregates of these fibers, such as paper, seeds, nonwoven fabrics, etc. It also includes reticular bodies and the like.

In the present invention, the length of the cloth or mat layer without the kneaded material applied at the end of the winding is preferably 1/30 or more and 1/3 or less of the outer circumference of the cladding tube. As will be described later, the effect of eliminating the protrusion at the end of the winding in the present invention is poor, and the
If the number is 3 or more, even if the water kneaded material is spread out in the next rolling and pressing step, a portion of only the cloth-like material remains, and peeling of this portion is likely to occur.

On the other hand, if a method is adopted to increase the fluidity of the water-kneaded material, there will be more falling loss of the water-kneaded material, and if the pressing force or pressing time is increased, the roundness will decrease and the manufacturing time will be increased. becomes long, which is not desirable.

In order to create a cloth or matte portion 2a(e) to which a water-kneaded material containing a hydraulic inorganic material as a main component does not adhere, a method is usually used in which the coating operation is carried out only on the required length of the cloth-like material. A method of gradually decreasing the amount of coating by adjusting the coating roller as it approaches the end of the area is also effective in the sense that protrusion can be more easily reduced.

The second step in the present invention is to eliminate the level difference in the beginning part 2b(s) of the winding, and to spread out the end part 2b(e) of the winding part 2b(e) while smoothing it into a part 2a(e) of only the cloth-like body at the end of the winding part. The protrusion height is continuously reduced through this process. FIG. 3 is a cross-sectional view of the cladding tube B obtained by subjecting the tube shown in FIG. 2 to the above-mentioned second step, and there are no protrusions at all. The method required for this leveling is not particularly limited as long as it is a method of uniformly pressing from the outside, but the most convenient method is to rotate the cladding tube that has undergone the first step around its axis and The above-mentioned treatment is carried out while pressing the uncured coated tube body against a rotating pressing roller or on two rotating rollers in the same direction, but the pressing force,
The rotation time is appropriately selected depending on the viscosity of the water-kneaded product and the length of the cloth-only portion 2a(e). It is most preferable that this second step is completed when the water-kneaded material has spread to the ends of the cloth-like body.

As the core tube for wrapping in the present invention, a synthetic resin tube or a metal tube can be used as it is, but a core tube for forming a tubular body is prepared separately, coated with a hydraulic inorganic material, and then coated with another desired material after curing. Of course, it is also possible to replace the core tube.

By carrying out the manufacturing method of the present invention as detailed above, the roundness of the cladding tube body is significantly improved, which not only eliminates troubles in combination with support fittings, joint fittings, etc. during piping, but also improves the appearance. improves.

The manufacturing method of the cladding tube according to the present invention enables the manufacture of a nearly perfect circle even with a small number of turns, such as 2 to 3 layers, so the use of cloth or mat can be kept to the minimum necessary, and the amount of hydraulic inorganic material per layer can be reduced. Since the coating thickness of the water kneaded material, which is the main component, can be increased, it has the advantage of being able to be used in combination with coarse aggregate for the purpose of increasing the volume.

Example Diameter 100 rotating inward with 2.8mm gap
2.1 m wide cheesecloth (material: cotton) and a mixture of water and a hydraulic inorganic material having the composition shown below are passed together through a parallel roller with a length of 2.5 m and 2.5 m long, and the mixture is uniformly spread on the cheesecloth to a thickness of 2.7 mm. The water kneaded product was applied.
The coating was applied to the entire surface, leaving about 100 mm of cheesecloth.

Composition Portland cement 100 (parts by weight) Silica sand 30 Light aggregate (perlite) 15 Asbestos 5 Thickening admixture (methylcellulose)
0.15 Water 47 Use this as a hard vinyl chloride pipe (outer diameter 114mm)
Wrap it in about two layers around the outer peripheral surface of the tube with the coated surface inside, continue to wrap the uncoated portion, and position the uncured coated tube body parallel to it while rotating it around its axis, In addition, a plated iron roller with an outer diameter of 200 mm rotating in the winding direction of the cloth material was pressed. The coated tube body having obtained roundness was cured by steam curing at 50° C. for one day and night, and then air-dried for two weeks. The thickness of the coating layer of this product fell within the range of variation of approximately 8.0 mm±0.5 mm, and the roundness was extremely good.

[Brief explanation of drawings]

Figure 1 is a perspective view of the cladding tube immediately after coating, Figure 2 is a cross-sectional view of the cladding tube shown in Figure 1, and Figure 3 is the cladding tube after pressing treatment. A cross-sectional view is shown. The symbols used in the drawings will be explained. 1... Hard vinyl chloride pipe, 2a... Cloth-like body, 2b... Water kneaded body, 2a(e)... Portion near the end of winding of the cloth-like body,
2b(s)...Water kneaded body at the beginning of rolling, 2b(e)...
...Water kneaded body at the end of winding, A... unpressed coated tube body, B... pressed coated tube body.

Claims (1)

[Scope of Claims] 1. While or after applying a water kneaded material containing a hydraulic inorganic material as a main component to a cloth-like body, the cloth-like body is wrapped around the outer peripheral surface of the tubular body with the coated side facing inside to produce a coated tube body. A method for producing a coated tube body, characterized in that the water kneaded material is applied to the cloth-like body, leaving only the vicinity of the end of the winding, wound around the outer peripheral surface of the tubular body, and pressed from the outer peripheral surface. 2. The method of manufacturing a cladding tube according to claim 1, wherein the length of the cloth-like body near the end of winding is 1/30 to 1/3 of the outer circumferential length of the cladding tube. 3. The method for producing a coated tube body according to claim 1 or 2, wherein the amount of the kneaded material is gradually reduced as it approaches the vicinity of the winding end of the cloth-like body. 4 Claims 1 and 2, in which the pressure treatment is carried out by rotating a tubular body around which a cloth-like body coated with a water kneaded material is wound around its axis and abutting a pressing rotating roller in parallel. A method for producing a coated tube body according to item 1 or 3.