RU209892U1 - 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 makes it possible to visualize the increase in the temperature of the product to critical temperatures by changing its color. The claimed cable product includes a multilayer sheath made in the form of a sheath, a layer with a reversible thermochromic applied to the entire surface of the sheath by co-extrusion, and a layer with an irreversible thermochromic applied to a part of the surface of the reversible thermochromic layer. EFFECT: dual temperature control of the cable product by indicating reversible and irreversible changes while maintaining high performance characteristics of the cable product sheath.

Description

This utility model relates to an electrical wire, cable and other electrical components designed to transmit electrical energy and changing color depending on temperature. Such cable products make it possible to visualize the rise in temperature of wire, cable and electrical components to critical temperatures by changing the color of the cable.

The jacket 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.

If 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 discovered 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 cable overheating, it is practiced to measure the temperature of the cable 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

Due to overheating of the cable, premature aging of the insulation can occur, which will lead to a decrease in insulating properties and possible premature failure. It is impossible to determine the place where the insulation has reduced properties without the use of additional equipment.

Known heat-sensitive conductive cable (CN 200941319 Y, G01K 11/12, publ. 29.08.2007), the surface of which is coated with a thermochromic layer that 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.

Below this critical temperature, the thermochromic layer has an opaque color; at or above the critical temperature, the thermochromic layer is in a transparent state. A reversible heat-sensitive pigment is used to make the thermochromic layer.

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 analogue is the lack of information due to the use of only one type of thermochromic pigment - reversible. The coating changes color and signals about overheating of the cable product only during the operation of the product; after disconnection, it is impossible to determine the place of overheating and possible damage.

Known heat-sensitive, color-changing cable (patent JP 2006294625 A, B65D 85/804, 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 thermochrome, the color of which changes with temperature.

The above thermochrome is a mixture of two or more types of thermochromes having different temperature sensitivity ranges.

Thermochrome, which 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 analogue is also the lack of information about the nature and place of overheating of the cable product due to the use of only one type of thermochromic pigment - reversible. Since a thermochromic dye (pigment or masterbatch) is added to the entire thickness of the protective outer sheath of the cable, the physical and mechanical characteristics of the sheath material deteriorate. 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 is a color-changing cable (Patent CN 102589728 A, G01K 1/02, publ. 03/19/2014), which is an analogue of the previously mentioned 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 thermochrome to the entire thickness of the shell. Thermochrome, which changes color when overheated, is reversible.

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

Known electrical wire or cable (Patent JPH 10241470 A, H01B 7/32, publ. 08/11/1998), changing color depending on temperature, in which the entire outer sheath or part of it is painted with a reversible thermochromic pigment to indicate temperature.

During extrusion molding of the shell, a reversible thermochromic temperature indicating pigment is usually blended into the entire outer shell or part of the shell as a strip within the shell, using a special extruder.

The amount of reversible thermochromic pigment having different color change as described above is preferably added at most 2 parts by weight. in relation to 100 wt.h. base polymer, such as polyvinyl chloride resin (PVC). The reason is that when the amount of 2 wt.h. the physical properties of the base resin, such as frost resistance, deteriorate.

The disadvantage of this analogue is the lack of information about the nature and place of overheating of the cable product due to the use of only one type of thermochromic pigment - reversible. In this case, it is possible to track the overheating of the cable product only during the operation of the product.

The disadvantage of this analogue is also a decrease in performance with insufficient introduction of thermochromic pigment, 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, results in a pale gray color instead of the expected black.

Known wire with enameled insulation (Patent CN 206331826 U, H01B 7/02, publ. 14.07.2007), which is a prototype. This wire includes a round copper wire 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 temperature indication is applied on the outside of the polypropylene layer, and a polyamide insulating varnish is applied on the thermochromic layer with temperature indication. . 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 only one type of thermochromic pigment - irreversible, 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 analogues do not provide sufficient information about the place and nature of overheating of the cable product. These analogues have only one type of thermochromic indication of overheating: either reversible or irreversible, while the formation of thermochromic layers reduces the performance of the cable sheath

Thus, the technical problem solved by the present utility model is to eliminate the shortcomings inherent in known analogues, namely: insufficient information about the place and nature of overheating of the cable product.

The technical result achieved in this case is a double control of the temperature of the cable product by indicating reversible and irreversible changes.

To solve this technical problem and achieve the claimed technical result, a cable product is proposed that changes color depending on temperature, including a multilayer sheath made in the form of a sheath, a layer with a reversible thermochrome applied to the entire surface of the sheath by co-extrusion, and a layer with an irreversible thermochromium, which deposited on part of the surface of the layer with a reversible thermochromic.

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

The irreversible thermochromic layer contains an irreversible thermochromic dye.

For the purposes of this application, the term "cable product" means a cable, wire, cord, etc., intended for the transmission of electrical energy, electrical and optical signals, or for the manufacture of windings of electrical devices.

"Sheath" - a protective coating applied to a cable product over other structural elements, designed to protect the cable product from damage and impart operational characteristics such as: combustibility, fire safety, cold resistance, etc. It is mainly made from polymeric materials such as PVC, PE, EVA, PU, TPE, rubber, etc.

"Insulation" is one or more layers of a special dielectric material that covers cable cores. It is mainly made from polymeric materials such as PVC, PE, EVA, PU, TPE, rubber, etc.

"Critical temperature 1" - the maximum allowable temperature of the cable product.

"Critical temperature 2" - the temperature at which the cable product loses its functionality, for example, due to damage to the insulation.

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

“Reversible thermochrome” is a thermochrome that changes its color upon reaching a predetermined temperature; during the reverse process, the color is restored to its original color.

“Irreversible thermochrome” is a thermochrome that changes its color when a given temperature is reached, and the color is not restored during the reverse process.

“Reversible changes” are those changes that are visible when the cable reaches critical temperature 1.

"Irreversible changes" are those changes that are visible when the cable reaches critical temperature 2.

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

"Layer with reversible thermochrome" - a layer for indicating changes containing a reversible thermochrome.

"Layer with irreversible thermochrome" - a layer for indicating changes containing an irreversible thermochrome.

"Multilayer sheath" - the sheath of a cable product, covered over the entire surface with a layer made of a polymeric material with the addition of reversible thermochromic. A layer with an irreversible thermochromic is deposited on a part of the surface of the layer with a reversible thermochromic.

"Basic polymer" or "base resin" - the basis of the polymeric material (compound) from which the insulation or sheath of a cable product is made.

"Extrusion" is a method of applying polymeric layers, such as sheath or insulation, to a cable product using an extrusion line.

"Co-extrusion" or "co-extrusion" - 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 figure 2, which shows a general view of the device, where

1 - multilayer shell,

2 - shell,

3 - layer with reversible thermochrome,

4 - layer with irreversible thermochrome,

5 - isolation,

6 - lived.

The cable product, which changes color depending on temperature, has a multilayer sheath (1), presented in the form of a sheath (2), a layer with a reversible thermochromic (3) and a layer with an irreversible thermochromic (4). The multilayer sheath (1) is applied to the conductive wires (6), which can be covered with insulation (5). The number and type of cores (6) 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 multilayer 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, and the like 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 reversible thermochromic layer (3) are made of a material containing the same base polymer, while the reversible thermochromic layer (3) is made with the addition of a reversible thermochromic pigment.

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

On top of the layer with reversible thermochromic, a layer with irreversible thermochromic (4) is deposited on a part of its surface. The irreversible thermochromic layer is a dye (paint, ink, etc.) with the addition of an irreversible thermochromic. The irreversible thermochromic layer is applied by dyeing or printing. The irreversible thermochromic layer can be applied in the form of one or more longitudinal stripes, as well as in the form of text.

A cable product with a multilayer sheath (1), including layers to indicate reversible and irreversible changes, 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 added to the reversible thermochromic layer (3) can be any of the pigments on the market presented by manufacturers, 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 1, the maximum allowable operating temperature of the cable, the reversible thermochromic layer (3) changes its color, for example from black to colorless, thereby signaling that the allowable 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 reversible thermochromic layer (3) returns to its original color.

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

During the overheating of the cable product above the critical temperature 2, at which premature aging and reduction in the insulating properties of the insulation (5) or failure of other structural elements occur, the layer with irreversible thermochrome (4) changes its color, for example, from black to red. After disconnecting the cable product, the temperature decreases, but in the place where the critical temperature 2 is exceeded, on the sheath, information about the temperature excess remains in the form of a changed color of the layer with a reversible thermochrome (4). Thus, by changing the color of the multilayer sheath, it is possible to detect the location of damage to the cable product.

The application of two types of thermochromic pigment on the cable jacket allows you to control the temperature changes of the cable product during operation and in case of damage. The layer with reversible thermochrome (3) shows the excess of the critical operating temperature 1 of the cable product during its operation and helps to prevent an accident. The layer with irreversible thermochrome (4) makes it possible to detect the place where the critical temperature 2 has been exceeded, and to detect the place of damage to the cable product, if it was not detected during operation.

The execution of the shell and layer with a reversible thermochromic polymer material containing the same base polymer by co-extrusion makes it possible to produce a shell that is a single whole and does not have the ability to exfoliate during operation. The production of a layer with a reversible thermochromic pigment from a polymeric material with the same characteristics as the main shell, with the addition of a reversible thermochromic pigment, makes it possible to preserve all the specified properties of the shell in the multilayer shell, for example, reduced flammability, cold resistance, etc.

Due to the reversible thermochrome, it becomes possible to detect overheating of the cable product during its operation. When the maximum operating temperature (critical temperature 1) is reached, the color changes on the surface of the cable product in places of overheating, so overheating can be visually detected without using additional measuring tools. When the temperature drops, for example, when disconnected, for example from the mains, the cable product, the color of its surface returns to its original color.

Due to the irreversible thermochrome, it becomes possible to detect the place of damage to the cable product due to overheating. When the cable product reaches the critical temperature 2, at which the insulation is destroyed, the color of the sheath changes at the place of overheating, while the color change occurs at the place where the irreversible thermochromic pigment is applied.

Claims (4)

1. A cable product that changes color depending on temperature, including a multilayer sheath made in the form of a sheath, a reversible thermochromic layer and an irreversible thermochromic layer, which is deposited on a part of the surface of the reversible thermochromic layer. 2. A cable product according to claim 1, characterized in that a layer with a reversible thermochrome is deposited on the entire surface of the sheath by co-extrusion. 3. Cable product according to claim 1, characterized in that the sheath and the reversible thermochromic layer are made of a polymeric material containing the same base polymer. 4. Cable product according to claim 1, characterized in that the layer with irreversible thermochromic contains a dye with the addition of irreversible thermochromic.

Images