JPS6026020B2 - Heat resistant lagging sheet - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a running sheet used for heat insulation or heat insulation protection of heating piping and the like.

Conventionally, inorganic fibers such as asbestos and glass fibers have been widely used as covering materials, or lagging materials, to protect high-temperature piping such as boiler piping. Occupational diseases such as allergies associated with skin irritation and problems related to the working environment have become more important, and new materials have been sought to replace these.
In addition, in order to avoid loosening and peeling when the tape-like lunging cloth is wound and coated on the pipe body, the cloth is impregnated or coated with a substance that develops adhesiveness by constant humidification, and then dried. In the past, a cloth was prepared, moistened with water and applied immediately before the coating work. However, with such known lagging cloths, it is necessary to prepare a moisture supply means each time the covering operation is performed, which is not only time-consuming, but also makes handling of the sticky tape itself inconvenient and unpleasant, resulting in poor workability. The current situation is that we are not necessarily satisfied with this aspect.

In view of the above-mentioned problems, the present inventors have created a material that is completely harmless to health, is easy to handle, has good workability, has excellent heat retention and insulation cushioning properties, and can form a more reliable coating layer. The present invention was completed for the purpose of providing a heat-resistant lagging sheet. That is, the present invention is characterized by integrating a nonwoven fabric made of heat-resistant organic fibers and a hot-melt portable porous thin layer made of a polymeric material having a melting point approximately 5000 or more lower than that of the woven fibers. It is a heat resistant lagging sheet.

The heat-resistant organic fibers applied to the present invention have different required properties depending on the conditions of use, but include, for example, fluorine fibers represented by polytetrafluoroethylene; polymetaphenylene isophthalamide, and polyparaphenylene terephthalamide. Fibers made of aromatic polyamides such as polytetramethylene adipamide, polyhexamethylene adipamide, polyoctamethylene adipamide, polytetramethylene adipamide, polydocapramide, etc. Fiber; made of aromatic polyester such as polyethylene terephthalate, polyethylene-p:p'-diphenylcarboxylate, polyhexamethylene-p:p'-diphenylcarboxylate, polyethylene-2:6-naphthalene dicarboxylate, etc. Fiber; Polyacrylonitrile fiber: Novolac fiber, etc., which have a high melting point,
It is preferably used because it has a high decomposition temperature and good heat resistance.

Of course, other than these, about 150 oo or more, preferably about 1
It goes without saying that any organic fiber that can withstand use for a relatively long period of time at a high temperature of 80 qo or more can be used as long as it satisfies the relationship with the melting point of the low melting point fiber described below.

Such heat-resistant organic fibers are formed into a nonwoven fabric in the form of short fibers.

The weave and fiber length of the short fibers can be selected as appropriate within the range that allows the sheet to be made into a non-woven fabric and the resulting sheet has sufficient heat-insulating and heat-insulating properties, but usually a single fiber with a total weave of 1 ~200
It is used with a denier and a fiber length of about 30 to 12 mm. Nonwoven fabrics can be made bulky with a lower basis weight than other fabrics such as woven or knitted fabrics, have excellent heat retention and insulation cushioning effects, and maintain appropriate elongation, so they can be used for pipes, etc. It is easy to wrap during wrapping work, and is particularly effective for processing complex shapes such as corner parts.

Such a nonwoven fabric can be obtained by any conventionally known or commonly used method such as so-called resin bond, needle felt, stitch bond, suction bond, bond, etc. However, methods using needling or stitching are It is particularly recommended because the resulting nonwoven fabric has sufficient bulk and has the advantage that it can be integrated with the hot-melt thin layer described later on-line.

The above-described nonwoven fabric is laminated and integrated with a hot-melt flexible porous thin layer to form the lagging sheet of the present invention.

The material constituting the flexible porous thin layer can be used sufficiently if it has a melting point difference of 50q0 or more with respect to the melting point of the heat-resistant fiber, but preferably has a difference of 150qo or less, particularly 12 pi○ or less, and more preferably 100q0 or less. It is a thermoplastic polymeric material that has a melting point, ie, a point where it begins to flow. Such materials include, for example, high-pressure polyethylene, polyvinyl chloride, polyvinyl alcohol, -chlorinated polyethylene, modified products thereof mixed with a small amount of microcrystalline petroleum wax, ethylene/vinyl acetate copolymer, etc. Vinyl polymers such as English polymers:
PolyJamides such as aliphatic polyamide copolymers, N-alkylated modified products, or C-alkylated modified products: polyethylene terephthalate/polyethylene adibate, polyethylene terephthalate/polyethylene sebacate, polybentamethylene/diphenoxyethylene -p: p' dicarboxylate, polydecamethylene/diphenoxyethylene, p: p' dicarpoxylate, and other polyesters; polyurethane in which both the aliphatic diisocyanate component and the diol component have 7 or more carbon atoms in the main chain. You can select from among the following types. However, the present invention is not particularly limited to these examples, and any thermoplastic polymer material that has the above-mentioned melting point range and has the ability to form fibers or films can be applied.

The sacrificial porous thin layer used in the present invention is made of the above-mentioned thermoplastic polymer material, has a thickness of 1 or less, preferably 0.5 or less, and covers the entire surface to allow gas permeation. It is formed in a porous manner so as to have pores.

Such a porous thin layer can be formed by forming a fibrous material made of the thermoplastic polymer material into a spiderweb-like web by a known spunbond method, a sprayed fiber method, etc., or by forming a film made of the polymer material by suitable means. or drill holes with
It can be easily obtained by layering split yarn or slit yarn obtained from a film alternately in warp and warp directions, and is made of thermoplastic polymer material and has a sufficiently thin porous shape, so it is flexible and maneuverable. rich in

Methods for laminating and integrating such a porous thin layer with the above-mentioned nonwoven fabric include forming a thin layer by directly spun-bonding or spraying low melting point polymer fibers onto the nonwoven fabric, and forming a thin layer separately. A method of adhering both layers adjusted to a neck layer and using an appropriate adhesive, or a method of adhering them by heating above the melting point of the polymer material while applying pressure as necessary, or Stitching with a stitching machine or integrating with needle punching, etc.
Various methods can be employed. In the above explanation,
Although we have mainly described the case where a flexible and porous lagging layer is laminated and integrated on only one side of the nonwoven fabric, the mutual adhesion of the lagging sheets is ensured by laminating the thin layer on both sides of the nonwoven fabric to create a three-layer foundation structure. It is also possible to easily make the heat insulation/insulation layer formed by multiple windings more solid, and to improve workability.

In addition, even if the heat-resistant organic fibers constituting the nonwoven fabric and the polymeric material J material of the flexible porous thin layer to be laminated to the nonwoven fabric are completely different, an appropriate adhesive may be used. Alternatively, they can be integrated by mechanical means such as needle punching or stitching, but it is preferable to select and use polymers of the same chemical type in consideration of the compatibility of both materials. That is, for example, when polyamide is used as a heat-resistant organic fiber, it is better to select a polyamide copolymer, modified polyamide, or polyurethane for the hot-melt polymer material, and for polyester, a copolymer Most preferably, a coalescing polyester is used.

By doing so, not only is the integration of both layers better, but when used as a lagging sheet, the hot-melt type layer, which can be softened and melted, has an excellent adhesive effect due to its affinity with the heat-resistant nonwoven fabric. Workability can be improved by ensuring reliable and firm bushing action on piping or between lagging sheets.

The heat-resistant lagging sheet thus obtained usually has a thickness of about 50 to 1
It is cut into a tape shape with a width of 0.5 cm and wrapped around a heated pipe to coat it. However, if the hot melt type porous thin layer is rolled inside, the porous thin layer will soften and melt due to the high temperature of the pipe. It develops adhesive properties and easily adheres to the pipe body, and the lagging sheets that are polymerized and wound together are also bonded to each other, so loosening due to tension reduction during winding is completely prevented, making it firm and reliable. A covering layer is formed.

In addition, the layer that is supposed to perform heat retention and insulation buffering effects is made of bulky nonwoven fabric with a low basis weight, so it has high heat retention and insulation efficiency.
Since it is made of heat-resistant organic fiber, its bulkiness is not affected by the high heat of the tube, and it can withstand long-term use.

That is, the product of the present invention has an excellent advantage that has not been seen in the past, in that although it can be easily thermally bonded to a heating tube etc., the heat retention/insulation effect is not impaired at all. Furthermore, since it is highly flexible as a whole and also has a suitable elongation, it is easy to wrap, and it is especially easy to handle corners and untreated areas, making it very convenient to handle. This guarantees high workability not found in conventional products.

Furthermore, since the hot-melt thin layer has a porous shape,
It has good compatibility with the nonwoven fabric layer, and has the feature that the entire coating layer is kept porous without forming a new heat generating surface in terms of heat insulation behavior, and has good heat retention.

Moreover, since the product of the present invention is made of materials that are completely harmless to health, it is also useful for workplace health and pollution prevention.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

Example 1 A web using staples made of polymetaphenylene isophthalamide (trade name: Nomex, manufactured by DuPont), which is a heat-resistant aromatic polyamide, with a single fiber weave of 2 denier and an average fiber length of 7.6 denier was fabricated with an average basis weight. The fiber aggregate obtained by laminating at a ratio of 120 pieces/piece was needle punched at 200 pieces/piece to obtain a nonwoven fabric with a thickness of 2.

On one side of this nonwoven fabric, N-ethylated polyhexane methylene adipamide with a melting point of 12,000 (N-ethylation rate of about 5
A spider web-like hot-melt web with a fabric weight of 20 mm/m was prepared by the spunbond method from 0%) and heated to a temperature of 14%.
Heat and pressure bonding was carried out for 5 seconds at 0° C. and a press pressure of 250 mm/base to obtain a lagging sheet with a basis weight of 140 mm/base and a thickness of 1. Its cross-sectional shape is shown in FIG. In the figure, 1 is a thin layer made of N-ethylated polyhexamethylene adipamide, and 2 is a non-woven fabric made of polymetaphenylene isophthalamide.

This material was cut into a tape shape with 50 ribs, and as shown in FIG. 2, it was wrapped twice over piping 3 heated to a temperature of 17,000 so that the hot melt thin layer 1 of the lagging sheet was on the inside. Since the thin layer 1 easily adhered to the tube body at the beginning of winding, the subsequent winding operation was extremely easy.

In addition, at the end of winding, the tape can be easily cut by pulling it by hand without using any cutter or other cutter, and by simply pressing the unturned end of the tape with your hand, it will be adhered to the tube body, and the tape will not loosen. I couldn't see it at all. As described above, the workability of the product of the present invention was significantly improved compared to the conventional product, and at the same time, the heat insulating effect was equal to or better than that of the conventional product.

Example 2 A porous film 4 having a basis weight of 35 mm was prepared using a polyurethane containing dodecamethylene diisocyanate and dodecamethylene glycol and having a melting point of 128 mm.

This material was laminated on a feed lattice with the same nonwoven fabric 5 with a fabric weight of 120 denier made of the same polymetapherenysophthalamide fiber as in Example 1, and then laminated with a 120 denier Nomex fiber thread using an Arachne machine for 38 courses. Chain stitching was applied to create a 40-wall product. The final finished product had a fabric weight of 160 tack, a thickness of 2.5 ribs, and was a stitch-bonded fabric with a hot melt thin film bonded to one side. When this product was cut into a tape shape with a width of 75 and used in the same manner as in Example 1, work efficiency was significantly improved compared to the subordinate product, and the work environment was also improved. Example 3 Polyethylene terephthalate with a melting point of 26,500 was spun to a single fiber weave of 3 denier, and the fabric weight was 3 using the spunbond method.
00 Evening/I made that non-woven fabric 7.

On one side of the polyester cocondensate (polyethylene terephthalate 48
A spider web 6 (with a basis weight of 30 ta') of a co-condensate of 58 hol% of polyethylene adipate and 58 hol% of polyethylene adipate was laminated to obtain a nonwoven fabric with a total basis weight of 330 ta and a thickness of 5 ribs. The nonwoven fabric thus obtained was made into the same machine as in Example 1,
When the thin film of the polyester cocondensate was wound on the inside of a pipe heated to 100 qC, workability was significantly improved compared to conventional products, a stable coating layer was formed, and the work environment was improved. has also been improved.

As is clear from the above examples, the present invention has no problem in terms of environmental hygiene because it integrates a nonwoven fabric made of heat-resistant organic fibers and a low-melting-point hot-melt flexible porous thin layer. This makes it possible to significantly improve the traditional work environment, and also to keep warm. To provide a lagging sheet that has excellent heat insulation effect, is simple and easy to handle, and has excellent practicality.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing one example of the lagging sheet of the present invention, Fig. 2 is an explanatory view showing the usage situation of the product of the present invention, and Figs. 3 and 4 show other examples of the lagging sheet according to the present invention. FIG. 1... Hot-melt sacrificial porous thin layer, 2...
...Nonwoven fabric, 3...Heating piping. Tanozu Takayukizuzutazuzuzuzuzuzuzuzuzu

Claims (1)

[Scope of Claims] 1. It is characterized by being formed by laminating and integrating a nonwoven fabric made of heat-resistant organic fibers and a hotmel type flexible porous thin layer made of a polymeric material whose melting point is 50° C. or more lower than that of the fibers. Heat resistant lagging sheet. 2 The heat-resistant organic fiber is polytetrafluoroethylene,
The heat-resistant lagging according to claim 1, which is one or more selected from polymetaphenylene isophthalamide, polyparaphenylene terephthalamide, polyhexamethylene adipamide, polyethylene terephthalate, polyacrylonitrile, or nopolac. sheet. 3. The heat-resistant lagging sheet according to claim 1, wherein the low melting point polymer material has a melting point of 150° C. or lower. 4. The heat-resistant lagging sheet according to claim 3, wherein the low melting point polymer material has a melting point of 100°C or less. 5. The heat-resistant lagging sheet according to claim 1, wherein the heat-resistant organic fiber and the polymeric material are chemically similar polymers.