JPH04189927A - Method for manufacturing antifreeze belt and belt-shaped body for antifreeze belt - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to an anti-freeze belt and a method for manufacturing a belt-like body for an anti-freeze belt.

(Prior Art) As shown in FIGS. 3 and 4, a conventional anti-freeze belt is made of a heating element 14 made of soft vinyl chloride and a core material 10A made of glass fiber or polyester fiber, and a heating element 14 wound with a nichrome wire 12. It has a structure covered with an outer skin 16. heating element 14
are arranged parallel to each other, with thermosknots 18 at the - ends.
connected via. The outer skin 16 covering the two heating elements is connected by an intermediate thin part 20, and the whole has a flat band shape.

(The problem FIfi that the invention seeks to solve) The antifreeze band is wound spirally around the outer circumference of the water pipe at an appropriate pitch, etc.
The tap water is prevented from freezing by wrapping a heat insulating tape over it or covering it with a heat insulating tube made of Styrofoam, etc., to keep it warm, and by energizing it.

In this way, the antifreeze band is used by wrapping it around the outer periphery of the water pipe, but since the water pipe has a small diameter of about 3 cm, the diameter of the antifreeze band inevitably becomes small when the antifreeze band is wrapped around it. For this reason, the outer skin 16 that covers the heating element is wound in a stretched state, and if this outer part is damaged by some external force, the outer skin 16 will split around this damage, exposing the heating element. There is a problem that short-circuit failures are likely to occur.

In particular, this type of antifreeze belt is often used outdoors and remains wrapped around water pipes not only during the winter but all year round, so the outer skin is exposed to harsh outdoor conditions. Furthermore, since the heating element is constantly turned on and off, the outer skin 16 is easily damaged and has a short service life.

The present invention has been made to solve the above problems,
The object is to provide an effective method for producing an anti-freeze belt and a strip for an anti-freeze belt which have particularly excellent durability.

(Means for Solving the Problems) The anti-freezing band according to the present invention for the above-mentioned purpose has a heating element in which a nichrome wire is spirally wound around a core material having flexibility and heat resistance, and a flexible outer skin. In the antifreeze belt having a belt-like body portion formed to cover the heating element, the heating element is flexible;
It is characterized in that it is coated with a resin film having electrical insulation properties, and the outer skin is coated on the resin film.

Further, in the manufacturing method according to the present invention, a method for manufacturing a belt-shaped body for an antifreeze belt in which a heating element in which a nichrome wire is spirally wound on a core material having flexibility and heat resistance is covered with a flexible outer skin. In the first molding step, the heating element is fed into a first molding machine, and a molten resin is extruded from the mouthpiece of the first molding machine onto the heating element to form a resin film; The heating element coated with the resin film is sent to a second molding machine,
The method is characterized in that it includes a second molding step of extruding molten resin onto a heating element from a mouthpiece of a second molding machine to mold the outer skin.

(Function) In the anti-freeze belt according to the present invention, the heating element is further covered with a resin film, so even if a crack occurs in the outer skin for some reason, the heating element will not be directly exposed, resulting in short-circuits, etc. can be avoided and durability can be significantly improved.

In addition to the outer skin, the heating element is covered with a resin coating, which increases its strength, allows the use of thin heating wires, and facilitates the creation of low-capacity heating elements (power-saving type).

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described in detail based on the accompanying drawings.

FIG. 3 is a partially cutaway view showing a strip 220 portion of the antifreeze strip according to the present invention.

10 is a core material, which is made of twisted fibers that are flexible, strong, and heat resistant, such as glass fiber or polyester fiber.

A nichrome wire 12 is spirally wound on this core material 10 to constitute a heating element 14.

This embodiment is characterized in that the heating element 14 covered with a resin film 24 is further covered with an outer skin 16.

In terms of cost, the outer skin 16 is preferably made of soft vinyl chloride resin as in the past, but is not limited to this, and other flexible resins or rubber may be used. One end side of the two heating elements 14a, 14b is connected via a thermostand (not shown) at one end of the band-shaped body 22, and the other end side is connected to a plug (not shown) to form an antifreeze band. be done. Note that a thermostat is not necessary when a temperature sensor is separately provided and a control circuit is separately provided to turn on and off the power supply to the heating elements 14-, depending on the temperature detected by the temperature sensor. In this case, the two heating elements 14a and 14b are directly connected at one end of the strip 22.

Of course, this connection part and the thermostat are separately covered with a suitable insulating material.

According to this embodiment, the heating elements 14a and 14b are covered with the resin coating 2.
4, the heating elements 14a and 14b will not be exposed even if cracks occur in the outer skin 16 for some reason, making it possible to avoid short-circuits and the like, thereby significantly improving durability. did it. Furthermore, the presence of the resin film 24 increased insulation properties and tensile strength. Furthermore, by using a heat-resistant material for the resin film 24, heat resistance can be further improved.

FIG. 2 shows a schematic diagram of the manufacturing process.

26 is a first molding machine for resin coating, 28 is a water tank, and 30 is a second molding machine for outer skin.

a heating element 14a in which a nichrome wire 12 is wound around a core material 10;
14b is fed into the first molding machine 26.

In the first molding machine 26, the molten resin is extruded from the extrusion hole of the mouthpiece 26a onto the heating elements 14a and 14b, and the resin film 2
4 is formed on the heating elements 14a and 14b (first molding step). Since the heating element 14 has unevenness on its surface with the nichrome wire 12 wound thereon, the adhesion between the resin film 24 and the heating element 14 is good.

The heating elements 14a and 14b coated with the resin film 24 pass through a water tank 28, where the resin film 24 is cooled down, and then fed into the second molding machine 30, where it is melted through the extrusion hole of the nozzle 30a. Extruding the resin onto the resin film 24,
The outer skin 16 and the connecting portion 20 are integrally molded (second molding step). Thereafter, it is cooled in a water bath to obtain a strip 22.

This strip 22 is cut to an appropriate length, one end of the cut and cut heating element is connected via a thermostat or directly, and the other end of the heating element is covered with an appropriate insulating material. is connected to a plug to complete the antifreeze strip.

In the above embodiment, an example in which two heating elements are arranged side by side has been described, but it is also possible to use one heating element with terminal portions formed on both ends.

Although various preferred embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that many modifications can be made without departing from the spirit of the invention. be.

(Effects of the Invention) As described above, according to the present invention, it is possible to significantly improve the durability of an antifreeze belt used under severe conditions such as outdoors. Furthermore, the method of the present invention has the remarkable effect of enabling continuous production of antifreeze belts.

[Brief explanation of the drawing]

Fig. 1 is a cutaway view of the belt-like body of the antifreeze band, Fig. 2 is a schematic diagram showing the manufacturing process, Fig. 3 is a plan view showing a conventional antifreeze band, and Fig. 4 is a cutaway view thereof. shows. 10... Core material, 12... Nichrome wire, 14.14
a, 14b...-Heating element, 16... Outer skin, 20... Connecting portion, 22... Band-shaped body, 24... Resin film, 2G... First molding machine, 30... Second molding machine. Figure 1

Claims (1)

[Claims] 1. An antifreeze belt having a band-like body portion formed by covering a heating element in which nichrome wire is spirally wound on a core material having flexibility and heat resistance with a flexible outer skin. An anti-freezing belt characterized in that the heating element is coated with a flexible and electrically insulating resin film, and the resin film is coated with the outer skin. 2. A method for producing a belt-like body for an anti-freeze belt, in which a heating element in which a nichrome wire is spirally wound around a core material having flexibility and heat resistance is covered with a flexible outer skin, in which the heating element is a first molding process in which the molten resin is fed into a first molding machine and extruded from the mouthpiece of the first molding machine onto a heating element to form a resin film; and the heat generated by the resin film coated in the first molding process A belt-shaped article for an anti-freeze belt, characterized in that it includes a second molding step of feeding the body into a second molding machine and extruding molten resin onto a heating element from a mouthpiece of the second molding machine to mold the outer skin. manufacturing method.