RU209916U1 - CABLE PRODUCT THAT CHANGES COLOR DEPENDING ON TEMPERATURE - Google Patents

Abstract

This utility model relates to a cable product designed for the transmission of electrical energy and changing color depending on temperature. Such a cable product allows you to visualize the temperature rise of the product to critical temperatures by changing its color. The claimed cable product includes a two-layer sheath made in the form of a sheath and a thermochromic layer deposited on the entire surface of the sheath by co-extrusion. The technical result is the preservation of the declared physical and mechanical characteristics of the sheath of the cable product, including the reliability of attachment to the sheath of the thermochromic layer.

Description

The present utility model relates to an electrical wire, cable or cord intended for the transmission of electrical energy and changing color with temperature. Such cable products allow you to visualize the temperature rise of a wire, cable or cord to critical temperatures by changing the color of the cable.

The sheath of cable products, such as wire and cable, is usually made of a polymeric material, such as polyvinyl chloride, and such products, for various reasons, can generate heat themselves, heat up due to heat generated by internal elements, or heat up due to external influences.

In cases where the components of the cable product are exposed to excessive heat in excess of their maximum allowable operating temperatures, the cable product may be damaged. It is not possible to track visually, without the use of additional measuring instruments, the effect of excess heat on the cable product. In many cases, the problem is detected too late, when the polymer components of the cable product begin to melt, warp, smoke, or ignite. In addition, if there are flammable substances or combustible materials in the immediate vicinity of such an abnormally heat-producing object, it may cause a serious accident such as a fire or explosion.

To prevent accidents associated with overheating of the cable product, it is practiced to measure the temperature of the cable product during its operation. Temperature measurement is usually carried out according to a set schedule by a non-contact method, such as a pyrometer, and may not provide a reliable result, since overheating of the cable may occur between measurements or in an inaccessible place for measurement.

Known wire with enameled insulation /Patent CN 206331826 U, H01B7/02, publ. 07/14/2007/, which includes a copper wire of circular cross section, coated on the outside with a layer of polyimide varnish, which is an insulating layer, the insulating layer is coated on the outside with a layer of polypropylene, a thermochromic layer with a temperature indication is applied on the outside of the polypropylene layer, a thermochromic layer with a temperature indication on the outside applied polyamide insulating varnish. This utility model can detect an increase in the operating temperature of the enameled wire, thereby preventing fire or accidents. The thermochromic pigment used in the thermochromic layer is irreversible, that is, it registers a temperature increase once.

The disadvantage of this analogue is the use of irreversible thermosensitive pigment in the specified thermosensitive wire, which allows you to register the critical temperature once. In the event of repeated overheating, the information will no longer be correct, because. on the wire with enameled insulation there will be a record from previous overheating.

Known heat-sensitive conductive cable /CN200941319Y, G01K11/12, publ. 08/29/2007/, on the surface of which a thermochromic layer is applied, which changes color with temperature. As a thermochromic layer, a special paint is used, which changes color with a critical temperature change, thereby creating a warning effect. In this case, the cable, which changes color at a critical temperature increase, may have several sections of the sheath on which a thermochromic layer is applied; each of the aforementioned areas responds to a certain level of temperature rise and changes color according to the critical temperature value.

Methods for applying a thermochromic layer on the outer surface of the specified conductive cable, which changes color at a critical temperature increase, can be as follows: printing, spreading over the surface, spraying and dipping.

The disadvantage of this analog is the unreliability of applying a thermochromic layer on the surface of the cable. The thermochromic layer applied by the above methods often rubs off, peels off or fades during the laying or operation of the cable.

The disadvantage is also that the paint applied to the surface of the cable (up to 3 layers) will worsen the non-combustible properties of the sheath in the case of the production of cables of reduced fire hazard, because. it does not contain flame retardants.

Known heat-sensitive, color-changing cable /patent JP2006294625A, B65D85/804, publ. 26.10.2006 /. Said cable, as shown in figure 1, consists of several sheathed conductors. The shell is made of a polymer material with the addition of a thermochromic dye, the color of which changes with temperature.

The above thermochromic dye is a mixture of two or more kinds of dyes having different temperature sensitivity ranges.

A thermochromic dye that changes color as a result of temperature changes is reversible.

The figure 1 shows: 1 - core, 2 - metal core, 3 - tape layer (for fastening the cores), 4 - sheath.

The disadvantage of this analog is that the thermochromic dye (pigment or masterbatch) is added to the entire thickness of the protective outer sheath of the cable, which worsens the physical and mechanical characteristics of the sheath material. In particular, the indicators of cold resistance are reduced in the case of the production of cables of the HL category.

As a result of adding a thermochromic dye to the sheath, the fire safety indicators of the cable may decrease, in the case of the production of cables of reduced fire hazard, by reducing the percentage of functional additives in the sheath, such as flame retardants, in the sheath material.

Also known color-changing cable /Patent CN102589728A, G01K1/02, publ. 03/19/2014/, which is an analogue of the previously indicated cable. It is a cable with a sheath that is sensitive to temperature and changes color when overheated, to indicate cable overheating without the use of a thermocouple or pyrometer. If you paint the cable with thermochromic paint on the outside, then when it is bent, the paint layer will crack, the paint will peel off and there will be no temperature indication. The problem is solved by adding paint to the entire thickness of the shell.

Such a cable has all the same disadvantages that were mentioned earlier.

Known electrical wire or cable /Patent JPH10241470A, H01B7/32, publ. 08/11/1998/, changing color depending on temperature, in which the entire outer shell or part of it is colored with a thermochromic pigment to indicate temperature.

During the extrusion molding of the shell, the temperature indicating pigment is usually mixed into the entire outer shell or part of the shell as a strip in the thickness of the shell, using a special extruder.

The amount of thermochromic pigment having different color change as described above is preferably added at most 2 parts by mass with respect to 100 parts by mass of a base polymer such as polyvinyl chloride resin (PVC). The reason is that when the amount exceeds 2 parts by mass, the physical properties of the base resin, such as frost resistance, deteriorate.

The disadvantage of this analogue is the reduction in performance, such as the visualization of the claimed color change effect.

Experiments have shown that 2% thermochromic pigment in the material gives a pale color, especially in non-combustible cable sheath materials, where the high content of flame retardants drowns out the color of the pigment. For example, 2% black thermochromic pigment in PVC grade PPO 20-30 used for low flammability casings produces a pale gray color instead of the expected black.

In the case of painting a part of the sheath, when laying the cable, the painted part may be hidden from view, thereby not fulfilling its function.

Thus, the technical problem solved by the present utility model is to achieve high performance characteristics of the sheath of a cable product when making a thermochromic pigment for temperature indication.

The technical result achieved in this case is the preservation of the declared physical and mechanical characteristics of the cable product sheath, including the reliability of attaching the thermochromic layer to the sheath.

To solve this technical problem and achieve the claimed technical result, a cable product is proposed that changes color depending on temperature, including a two-layer sheath made in the form of a sheath and a thermochromic layer applied to the entire surface of the sheath by co-extrusion.

The shell and the thermochromic layer are made of a polymeric material containing the same base polymer.

PVC, PE, EVA, PU, TPE, rubber and others can be used as the base polymer.

For the purposes of this application, the term "cable product" means a cable, wire, cord intended for the transmission of electrical energy, electrical signals

“Sheath” is a protective coating applied to a cable product over other structural elements, designed to protect the cable product from damage and impart performance characteristics such as reduced flammability, fire safety, cold resistance, etc. It is mainly made on the basis of polymeric materials.

"Insulation" is one or more layers of special dielectric material that covers cable cores. It is mainly made on the basis of base polymers.

"Critical temperature" - the maximum allowable operating temperature of the cable product.

"Thermochrome", "thermochromic pigment" or "thermosensitive pigment" is a microencapsulated substance introduced into the sheath of a cable product, which changes its color when a predetermined temperature is reached.

“Reversible thermochrome” is a thermochrome that changes its color when a given temperature is reached; during the reverse process, the color is restored to its original color.

"Reversible changes" are those changes that are visible when the cable reaches a critical temperature.

"Thermochromic layer" - a layer for indicating changes, containing thermochromic.

"Two-layer sheath" - a sheath of a cable product, covered over the entire surface with a layer made of a polymeric material with the addition of a thermochromic pigment. It is a combination shell.

"Basic polymer" or "base resin" - the basis of the polymer material from which the insulation or sheath of the cable product is made; For cable products, base polymers such as PVC, PE, EVA, PU, TPE, rubber, etc. are mainly used.

"Extrusion" - a method of applying polymer layers, such as sheath or insulation, to a cable product using an extruder;

"Co-extrusion" or "co-extrusion" is a method of applying an additional layer to the sheath of a cable product using an additional extruder, simultaneously with applying the sheath.

Further, the claimed cable product is illustrated by a figure, which shows a general view of the device, where:

1 - two-layer shell

2 - shell

3 - thermochromic layer

4 - isolation

5 - lived.

A cable product that changes color depending on temperature has a two-layer sheath (1) presented as a sheath (2) and a thermochromic layer (3). Sheath (2) and thermochromic layer (3) are applied to conductive wires (5), which can be covered with insulation (4). The number and type of cores (5) in a cable product may vary depending on the brand and size of the cable product. The cable product may contain such structural elements (not indicated in figure 2) as: threads, fastening tapes, copper screens, polymer filling and other elements necessary to give the cable product the desired performance properties. As mentioned above, on top of all structural elements, the cable product is covered with a two-layer sheath (1), the first layer of which is represented by sheath (2). The shell (2) is made of a polymeric material, which is based on the base polymer. As the base polymer, for example, PVC, PE, EVA, PU, TPE, rubber, etc. can be used. In this case, the choice of polymeric material from which the sheath (2) is made is determined depending on the purpose of the cable product, for example, to impart frost-resistant or refractory qualities, etc.

The shell (2) and the thermochromic layer (3) are made of a material containing the same base polymer, while the thermochromic layer (3) is made with the addition of a reversible thermochromic pigment.

The thermochromic layer (3) is deposited on the surface of the shell (2) by co-extrusion. Thus, the thermochromic layer (3) forms a single whole with the shell (2), a two-layer shell (1), without violating the physico-mechanical characteristics of the shell (2).

A cable product with a two-layer sheath (1), which is a combined sheath, is able to change its color with temperature changes, for example, when heated above critical temperatures.

The temperature at which the cable product changes color is selected from the range from +15°C to +70°C, depending on the type and design of the cable product.

The color of the thermochromic pigment introduced into the thermochromic layer (3) can be any of the pigments presented by the manufacturers on the market, including those with a direct thermochromic effect, reverse and with a transition from one color to another.

The claimed cable product works as follows.

During overheating of the cable product above the critical temperature, the thermochromic layer (3) changes its color, for example from black to colorless, thereby signaling that the permissible operating temperature has been exceeded. Thus, the maintenance personnel sees deviations in the operation of the cable product and takes measures to prevent an emergency. After lowering the temperature of the cable product, the thermochromic layer (3) returns to its original color.

Those. such temperature changes are reversible, the cable product is suitable for further operation

The execution of the shell and the thermochromic layer from a polymeric material containing the same base polymer by co-extrusion makes it possible to produce a two-layer shell, which is a single whole and does not have the ability to exfoliate during operation.

The formation of a two-layer sheath by applying a thermochromic layer over the entire surface of the sheath by co-extrusion, in such a way that it is a single unit with the sheath, avoids the deterioration of the physicomechanical and chemical properties of the cable sheath itself, since the thermochromic pigment is not added directly to the sheath, respectively it does not adversely affect the specified characteristics of the cable sheath. The manufacture of the shell and the thermochromic layer simultaneously by co-extrusion guarantees their reliable bonding over the entire surface and the impossibility of peeling off the thermochromic layer, because shell and thermochromic layer are one.

In turn, the thermochromic layer is made from a polymer material with the same characteristics as the main shell, with the addition of a thermochromic pigment, which makes it possible to preserve all the specified properties of the shell in a two-layer shell, for example: reduced flammability, cold resistance, chemical composition of smoke during combustion, etc. .

Claims (1)

A cable product that changes color depending on temperature, including a two-layer sheath made in the form of a sheath and a thermochromic layer applied to the entire surface of the sheath by co-extrusion, while the sheath and thermochromic layer are made of a polymer material containing the same base polymer.

Images