JPH028010A - Manufacture of cement-based covered tube - Google Patents

Abstract

PURPOSE:To eliminate thread shifting (stich shifting) and the like and consequently realize favorable external appearance of a tube and, at the same time, improve its yield and productivity by a method wherein thermowelded flat yarn cloth is used as olefin-based cloth, onto which matter mainly consisting of cement-based inorganic material kneaded with water is applied, and the width between fibers of cloth and its opening ratio are set within the predetermined range. CONSTITUTION:The surface of flat yarn cloth is coated with hydraulic cement mortar. The coated surface is wound round the surface of a core spingle (winding spindle) in two or three plys. As the flat yarn cloth, crystalline polymer such as polyethylene, polypropylene or the like, which is extruded in film, stretched, divided in the width of 5mm or less, preferably in the width of 0.5 to 1.5mm, so as to be combined crosswise or diagonally, when necessary, and thermowelded at the points of intersection in order not to develop stich shifting in cloth, is used. Further, the opening ratio (the ratio of space not occupied by flat yarn to the space of cloth) is 25 to 80%, preferably 40 to 60%.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a fire-resistant drainage pipe in which a synthetic resin pipe such as a hard vinyl chloride pipe is coated with a cement-based cladding pipe to provide soundproofing and earthquake resistance, etc. This product relates to fire-resistant ventilation pipes, etc., and manufactures cement-based clad pipes that prevent the spread of fire and smoke from upper and lower floors and adjacent rooms when used in fire-resistant buildings such as apartments, hotels, and offices. It is about the method.

[Prior Art and Problems to be Solved by the Invention] Conventionally, asbestos-cement coated vinyl pipes (asbestos pipes) have been used in this field, and have been mainly manufactured by a paper-forming method. In recent years, asbestos has caused lung cancer such as mesothelioma.
Its use is being regulated both overseas and domestically. Fibers such as ARG (alkali-resistant glass fiber), vinylon, and polypropylene are being researched as substitutes for asbestos, but they are insufficient in terms of strength (especially impact resistance), fire resistance, and cost, and fire-resistant cladding Many problems remain in terms of performance and economy in its application.

In addition, instead of the conventional paper-making method, a method has been proposed in which a mixture of hydraulic inorganic materials and water is coated on cheesecloth such as vinylon and wrapped in two or three layers to produce a pipe body. Although it is effective in increasing the strength of combustible organic fibers, it reduces the commercial value of the appearance and other aspects, and the process is complicated. Furthermore, Japanese Patent Publication No. 5,998,840 proposes a method of treating cheesecloth with an aqueous synthetic resin solution, but this method makes the process even more complicated and requires a considerable increase in the amount added in order to be effective. This will result in higher costs.

[Means to solve the problem]

In order to solve the above problems, the present inventor used a flat yarn cloth heat-sealed to an olefin cloth,
The inventors have discovered that if the width between the fibers of the cloth and the opening ratio are set within a predetermined range, there will be no thread misalignment (stitch misalignment) and the appearance will be good, and the yield will be good and productivity will be significantly improved. It was completed.

In other words, the gist of the present invention is to provide a method for manufacturing a coated tube body by coating a polyolefin cloth with a water kneaded material containing a cement-based inorganic material as a main component or wrapping it around the outer periphery of a tubular body after coating the polyolefin cloth. A cement-based heat-sealed flat yarn cloth with a width of 5 m1 or less of fibers intersecting vertically, horizontally, and/or diagonally, the cloth having an open area ratio of 25 to 80%. A method for manufacturing a coated tube body.

The present invention will be explained in detail below.

When using conventional plain-weave or rough-weave cheesecloth, as shown in Figure 2, the fibers themselves have unevenness, and the load during roll-forming has the disadvantage that the threads of the cheesecloth shift or the ends of the rolls shift, which impairs the appearance. .

On the other hand, the present invention has a thickness of 50 to 3 mm as shown in FIG.
A polyolefin flat yarn cloth made of polyethylene, polypropylene, etc. is used, in which flat yarns of 0.00 μm are heat-sealed to each other in the vertical and horizontal directions. Heat fusion can be easily achieved using a pressure roller or the like. However, since polyolefin flat yarns have almost no hydrophilicity and are hardly compatible with cement, it is necessary to use yarns with specific dimensions as described below.

In the present invention, the surface of the flat yarn cloth is coated with a water kneaded material mainly composed of a cementitious inorganic material. It is made by adding fluidizing agents, shape preservatives, reinforcing inorganic or organic fibers, etc., and kneading it with an appropriate amount of water. It can be anything that has been conventionally used in this field, and there are no particular restrictions. do not have.

The method for making a cladding body using this water kneaded material may also be a normal method. For example, first, hydraulic cement mortar is applied to the surface of the flat yarn cloth according to the present invention, and the coated surface is used as a core shaft (winding shaft). Roll up 2 to 3 layers on the surface.

However, in the present invention, the flat yarn cloth is made by extruding a crystalline polymer such as polyethylene or polypropylene into a film, and then stretching it and dividing it into pieces of 5 mm or less in width, preferably 0.5 to 1.5 mm lengthwise.

They are combined in the horizontal direction, and in some cases in the diagonal direction, and the crossing points are heat-sealed to form a cross with no misalignment. Also, this aperture ratio (ratio of space without flat yarn) is 25
-80%, preferably 40-60%.

The reason for using this method is as follows. There is almost no affinity between polyolefin fibers and cement cured products. In extreme terms, even if a film with almost no openings is made into a glue roll with hydraulic cement mortar, it lacks stable adhesion, and even a slight impact will cause the hardened mortar to fall apart. However, as in the present invention, when selecting fibers having a width of 51 or less and an aperture ratio of 25 to 80%, a cement composite with excellent reinforcing effect can be obtained. Although the principle behind this is not clear, it is thought that it is simply due to the entanglement of the flat fibers (thin film) and the matrix of the hydraulic cement mortar and the distribution density of the fibers.

From a practical point of view, if the open area ratio is less than 25%, the mortar is likely to peel off and collapse; if it exceeds 80%, the reinforcing effect by the fibers is insufficient.

Also, when manufacturing a coated tube body by wrapping it around the outer circumference of a tube body, the interval between flat yarn cloths is usually 0.5 to 5 mm.
, and more preferably 1.5 to 3 degrees, since there is no oil separation between the cloth and the hydraulic cement mortar. The number of heat-sealed intersection points on the cross surface is preferably 200 to 5,000 per 100 c.

For this reason, the reinforcing effect of this flat yarn cloth is not only due to the dispersed concentration of fibers, but also due to the fact that these intersection points are firmly heat-sealed. This is because internal "slippage" can be kept to a minimum, and slippage of the fiber itself can be almost completely eliminated. In other words, the effect of the present invention is nothing but a synergistic effect due to the combination of the flat yarn cloth and the hydraulic cement mortar matrix.

In addition, because of the manufacturing method and the structure shown in Figure 1, flat yarn cloth has a smooth cross-section with fewer irregularities than other plain weave and rough weave fibers, and when rolled into a tubular shape with hydraulic cement mortar, yarn slippage ( It can be wrapped smoothly without any misalignment. Further, the cement-based coated tube body obtained by the method of the present invention has a good appearance due to the roll-forming manufacturing method, and since no special process is required, the yield is improved and productivity is significantly improved. The coated pipe body manufactured by this method has water resistance and weather resistance of 1 and 1 compared to conventional asbestos pipes, and has much better impact resistance, making it possible to provide pipes that are less likely to crack.

〔Example〕

1m wide], 150μ thick stretched polyethylene fibers intersect and the intersection points are heat-sealed (flat yarn cloth)
Approximately 20% of the hydraulic cement mortar with the following composition was placed in the roll forming test machine shown in Figure 3 with an opening ratio of 45% and an opening width of 2m11).
It was coated to a thickness of mm and rolled three times around a winding shaft to form a roll.

Portland cement 60 parts Silica sand and lightweight aggregate (perlite) 40 parts Methyl cellulose
0.1 part water
30 copies This winding shaft was cured with steam at 60°C for 5 hours, and after curing, the cement mortar tube extracted had no thread deviation or mesh deviation, and the end of the winding was smooth.
The exterior was beautiful. A 1 kg drop impact test was performed on this cement mortar pipe, but no damage was observed.

〔Effect of the invention〕

The cement-based coated tube produced by the method according to the present invention maintains the simplicity of the process, has good performance such as impact resistance, has a beautiful appearance, and improves productivity.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a flat yarn cloth used in the present invention, in which (a) is a cross-sectional view and (b) is a plan view. Second
The figure is a cross-sectional view of a conventional plain-woven or rough-woven cloth. FIG. 3 is a schematic diagram illustrating the method of the embodiment. Figure 1 (Q,) Figure 2

Claims (1)

[Claims] 1. In the method of manufacturing a coated tube body by coating a polyolefin cloth with a water kneaded material mainly composed of a cement-based inorganic material or after applying it and wrapping it around the outer periphery of a tube body, the vertical, horizontal, and (or) the production of a cement-based cladding tube body, which is a heat-sealed flat yarn cloth in which the width of diagonally intersecting fibers is 5 mm or less, and the opening ratio of the cloth is 25 to 80%. Method.