What is cambric? Heat shrink for wires: dimensions, characteristics, application. Heat-shrink tubing. Heat shrink tube prices

In electricity, the main thing is good contact and reliable insulation. Often the former depends on the latter. For insulation, you can use insulating tape, but over time the properties of the sticky coating are lost and it can unwind and come off the cable under mechanical stress. A cambric is a PVC or rubber tube with good dielectric properties, most often white, beige or cream in color. From the article you will learn what cambrics are needed for and what they are, as well as how their types differ.

What is cambric used for in electrics?

The main task is to insulate electrical cables, but people have come up with a lot of other uses, from the role of covers for screwdrivers and awls, to use in fishing gear. (already prohibited by the PUE), soldering, welding, bolts, sleeves, as well as wires terminated with terminal lugs must be insulated. Most of these connections can be fitted with a cambric. For additional fixation and protection from moisture, the edges are fixed with electrical tape, and if one of the edges is free, it is heated with a lighter and squeezed with pliers.

In addition to insulating the connections, you can restore the insulating layer of the wire using cambric, securing its edges with electrical tape so that it does not move. This type of insulation is suitable for DC and AC circuits up to 1000 V.

An additional function is marking. A black felt-tip pen or marker is clearly visible on light cambric. In any circuits, both power and signal and communication lines, a casing with the designation is placed at the ends of the cable near the terminal.

Cambrides come in different sizes; select products that are a couple of millimeters larger than the diameter of the cable, otherwise it will constantly fall off or not fit. If you try to stretch it to the required diameter, it may burst, because... There is almost no size reserve for this product. They do not have this drawback. In addition, PVC pipes dry out and crack when heated, and become very hard in cold weather.

Heat-shrinkable tubes - shrink when heated

Although a heat-shrinkable tube or cambric performs the same tasks, it differs from the usual one both in the method of application and in the material from which it is made. Typically these are polyethylene and other polymers.

Heat shrinkage when heated can decrease by half. This advantage allows the same tube size to be used for a much larger range of wire sizes. This gives a definite advantage when used as insulation for various kinds of terminals and connections, because the shape of the terminal strip does not affect the quality of the covering. The heat shrink will shrink and follow any contours.

Heat shrinkage stretches well, up to 1.5-2 times its original value, but this must be done carefully, ensuring the integrity of the surface. This way you can stretch heat shrink onto wires and terminals if you don't have the size you need.

The next difference from heat-shrinkable PVC tubes is their appearance - they are sold in any color, including completely transparent or with color. This opens up even more conveniences for marking, for example, the wires of one group are divided by color and labeled by contact. Like regular cambrics, these products are inexpensive, but they can be found in every electrical or household goods store.

How to use cambric

Ideally, shrinking should be done with a stream of hot air. Any hair dryer is suitable for this. But more often it happens that it is not at hand or there is nothing to connect it to.

The second option is a soldering iron. Walk the heating element casing over the surface of the tube and it will shrink. The stinger does not need to do this for three reasons:

1. Too high a temperature can melt the cambric.
2. The sting leaves traces of soot.
3. So as not to spoil the sting.

The third option is to use fire sources. This could be matches or a lighter. Keep the flame a couple of centimeters from the heat shrink, so as not to damage it, walk with quick and short movements on all sides to achieve uniform contraction of the insulating layer. For a quick effect, you can do this directly with the flame, then the movements should be even faster, and you should be more attentive. The disadvantage of this method is that traces of burning may remain on the cambric. Turbo lighters do not have this drawback, but the flame temperature is very high and it is easy to burn the pipe, so keep the flame stream away so that only streams of hot air hit it.

The video example clearly shows how to use casings for wires:

Heat-resistant insulation - what is it?

Fiberglass tubes are a type of cambric that is resistant to high temperatures and can withstand temperatures from -60 to 510 degrees without problems. Fiberglass is impregnated with varnishes to improve electrical insulating properties. Such designs are often found in electric kettles, heaters, electric stoves and similar equipment. They are put on the supply wires and wires of internal connections near heating elements and spirals. Heat-resistant wire casings protect the contacts from temperature, thereby reducing the likelihood of corrosion and weakening, as well as melting of the insulation. They cost more than others, so their use everywhere does not make sense.

Alternative uses. Do-it-yourselfers and radio amateurs use heat-resistant fiberglass tubes for insulation, burners and similar devices. For example, they are put on the tip under the spiral to prevent inter-turn short circuits. During operation, the varnish burns, after which it continues to perform its tasks and does not burn out.

Wire casings are, in some cases, better suited for insulating conductors and joints than insulating tape. Their price and ease of use make it possible to increase the quality, safety and durability of electrical devices and circuits. Of course, this is an essential consumable for an electrician, it looks more aesthetically pleasing than electrical tape, and is more reliable in some cases, but it is better to use both in pairs.

Proper insulation of electrical wiring is a guarantee of safe living in the living space and the use of household appliances in everyday life. For this purpose, special twisting, soldering and crimping were developed. These consumables allow you to create contact between electrical conductors. Thanks to such measures, it is possible to avoid electric shock and short circuit.

A popular insulation is a plastic tube made of polyvinyl chloride. The scientific name of this material is cambric. According to physical law, a rubber surface does not conduct electric current.

What is cambric?

In simple terms, a cambric is a short piece of plastic tube that is made from components with a high degree of resistance. More than ten years ago, only hard models of the material were available for sale. They were selected according to the size and diameter of the electrical wire.

Today, heat-shrinkable casings are in particular demand. As the rubber surface heats up, they decrease in size several times. In addition, the insulating material changes its structure and reliably fixes the connections of the conductor circuit.

The diameter of the cambrics is selected in accordance with the number of cores in the wire. The greater their number, the wider the connecting hole should be.

Modern products help prevent corrosion of metal elements. Tubes made of durable rubber are affordable.

Types of consumables

There are several types of cambrics. They differ in their composition and scope of application. Insulating materials are divided into:

• ordinary (heat-resistant);
• thermodependent.

The usual ones are pieces of plastic tubes that consist of polyvinyl chloride. Available in several colors and diameters. They are also called PVC cambrics. They are designed for insulating multi-core wires.

Heat shrink products are made from special cotton paper and fiberglass. Their surface is covered with a special resin. Fiberglass cambrics require heat exposure.

Under the influence of high temperature, they begin to melt. As a result of this, a dense plastic shell is formed at the junction. In the future, it prevents the semiconductors from coming into contact with each other.

Most often they are used for electrical networks where the voltage does not reach a direct current level of more than 1000 W. In addition, this insulation is used for electronic boards. They help make adhesions at joints. The cambric acts as additional protection. It prevents bending, corrosion and mechanical damage to wires.

Heat-resistant cambrics are a tube of one size and a fixed diameter. To ensure strong insulation, it is recommended to carefully select the wire parameters. For example, if the thickness of the conductor is significantly less than the size of the cambric, then the insulator will not fit tightly to the solder surface. This increases the risk of short circuits and premature failure of the device.

The main disadvantage of heat-resistant insulation is that it practically does not stretch, unlike heat-shrinkable insulation. If used incorrectly, the rubber casing may burst, thereby increasing the risk of a sudden surge in electricity.

Which type of cambric is better?

When going to a specialized electrical goods department, many consumers often ask the question: “Which wire casings are best to use?” The right choice largely depends on what type of insulation you plan to perform. For example, in order to prevent short circuits on electrical boards, it is necessary to choose heat-shrinkable material. It tightly fixes the area of ​​interaction of parts.

When exposed to high temperatures, it begins to melt, thereby creating resistance in the area of ​​open sections of the conductor circuit. The diameter of the heat shrink tube should be 2 mm larger than the thickness of the wire.

For electrical appliances with high temperature conditions, it is necessary to choose heat-resistant insulators. They have thermal protection and high-quality insulation.

The advantages of consumable thermal material include:

• wide temperature range. These products can be used at different levels of an electrical circuit;
• safe composition. During the heating process of the plastic surface, no toxic substances are released that negatively affect human health;
• long service life;
• does not come into contact with chemical components. As a result, the risk of premature equipment failure is reduced;
• Excellent resistance to corrosion of parts and oxidation of metal surfaces.

Modern models of heat shrink material have an additional substance in the inside of the tube. When heated, it increases the adhesive ability of the plastic. Thanks to this, the connection point has a good seal. The heating temperature of the insulator surface is 60°C.

Ordinary cambric also has good electrical insulating ability. To do this, you need to choose the right size and diameter of the rubber tube. The main advantage of this product is its repeated use. If a crack appears on the surface of the product, its further use is prohibited. In addition, it has a low cost.

Heat-resistant insulators are often used in the design of an induction furnace, oven or drying chamber. It protects the place where semiconductors are fixed in the electrical circuit and reduces the impact of high temperature on device parts. You can mark adhesions on its surface.

Technical characteristics of heat-resistant material include:

• electrical impermeability. This type of insulator practically does not conduct electric current;
• The wall thickness of the product reaches from 2 to 2.5 mm. This makes it possible to create a strong barrier on the electrical circuit;
• fire resistance;
• large selection of tube diameters;
• high level of temperature exposure. It is used in areas of the electrical circuit with temperatures from -55 to 600 °C. The photo of cambrics shows models of insulating material.

Photos of cambrics

Heat-shrinkable tubing (abbreviated HERE) was invented back in the 50s of the last century. It was obtained by changing the molecular structure of polymers.

It is called differently: heat-shrinkable, heat-shrinkable, thermal cambric or simply thermotube. This does not change the essence, since these are all the same products.

Its main task is to isolate contacts, but besides this, there are additional ways to use such devices:

• shrinkage onto the butt of a wooden or metal pole of a power transmission line to protect against corrosion and rotting of wood in the ground

• insulation of metal and water pipes from aggressive environments

The use of heat shrinkage is based on the shape memory effect. This is achieved through radiation exposure.

If, for example, a polymer is placed in a powerful flow of electrons, then at the molecular level, neighboring macromolecules are connected to each other. This technology is called cross-linking technology.

After this operation, the polymer itself becomes more elastic, and the product, when heated, acquires its original shape and original dimensions.

Theoretically, the same tube can be seated an infinite number of times. If you had a device for heating and inflating it, it would turn into a reusable product. Moreover, its shelf life in its original state is tens of years. All characteristics and quality of the product, subject to certain requirements, do not depend significantly on the date of manufacture.

Today, heat shrink tubing has gained enormous commercial and technical importance throughout the world. However, the main area of ​​application remains in the fields of electronics and electrical engineering.

Thermal tubes are much more efficient than conventional tubes, which are brand TV-40. In addition to technical resistance, they also have chemical resistance. And this allows you to reliably protect insulation and contacts in places with aggressive environments - underground, in wells, cable ducts.

Types of heat shrinkage

Here are the main types of heat-shrinkable tubes widely used in everyday life and industry (from the KVT company), their sizes and characteristics:

Heat shrink tube TUTng 2k1Transparent tube KST 2k1Colored tubes HERE 2k1Yellow-green TUTng z-z

Yellow-green heat-shrinkable tubes TUTng z-z

Thick-walled and high-voltage heat shrink grades:

Thick-walled TST 3k1Anti-tracking TST-A 3k1Thick-walled non-flammable TT-S ngHeat-shrinkable tape TLK-10Tube for tires 10kv TTSH-10Tube for tires 35kv TTSH-35

Thick-walled TST 3k1

Heat shrinks of special design:

Repair cuffsReinforced cuffs Cable caps Heat shrink 6k1 Casings With TTK adhesive layerMedium-wall STTK

Characteristics and differences

What types of heat shrinks are there and how do they differ from each other?

Diameter before and after

The heat-shrinkable tube changes diameter when heated. Therefore, the name should always include the size BEFORE and AFTER shrinkage.

For example, tube HERE NG 40/20

• internal diameter 40mm - BEFORE
• full shrinkage diameter 20mm - AFTER

Shrinkage coefficient

The next criterion is the shrinkage coefficient. What it is? This is the ratio of the original diameter to the diameter after the shrinkage process. That is, depending on the coefficient, the tube is reduced several times. There are odds:

• 2 to 1
• 3 to 1
• 4 to 1
• 6 to 1

The larger it is, the more difficult the product is to manufacture. Accordingly, their prices differ significantly. However, 4 to 1 tubes are considered more versatile than 2 to 1.
If you connect two wires of different sections and different thicknesses, without heat shrinkage with large coefficients. you can't get by.

Wall thickness

Thermal tubes can have different wall thicknesses. According to this criterion they are divided into:

• thin-walled
• mid-range
• thick-walled

In addition, the thermotube can be adhesive - brand TTk. This is the one that has a layer of hot-melt adhesive applied to the inner surface. When heated, the glue melts and fills all microvoids, thereby ensuring complete sealing.

The walls stick to almost any surface. Excess glue should protrude around the edges.

It will not be possible to replace such hot-melt adhesive by first coating the inner walls of a simple tube. It is applied precisely during its manufacture. In addition, the adhesive coefficient of heat shrinkage is greater than that of a regular one - 3 * 1 or 4 * 1 versus 2 to 1. It can also be designed for greater stress due to the thickness of the walls.

Non-flammable

The material from which the product is made is of great importance. It is thanks to the composition of this material that the necessary properties are set in advance. If, for example, fire retardants are added to the composition, the tube acquires self-extinguishing properties and is designated by the NG index.

This does not mean that it does not burn at all. But in the absence of an external source of flame, it will quickly go out. This is achieved by preventing the flow of oxygen to the fire site with fire retardants.

Please note that if you use VVGng cable indoors, then you need to insulate the contacts and connection points with heat shrink only with the NG brand.

In this case, you can no longer use the usual cheaper option.

Color

Heat shrink tubing comes in a variety of colors, including clear ones. They are mainly used for marking.

They are very convenient for marking the ends of the cable, if you adhere to the old rules of color designation of phases. It is enough to place individual pieces on the end of the core.

For phases A-B-C, buy J (yellow) - G (green) - K (red).

But according to the new GOST, fA-fV-fS correspond to the colors K (brown) - CH (black) - S- (gray). Here you will have to use transparent tubes, or buy them to order.

There is also an original solution using multi-colored tape, on top of which a transparent thermal tube is applied. So the phases will be marked according to the new rules.

If you do not need color designation of phases, then take black ones. They are cheaper, and the quality of insulation is the same.

This is due to the specifics of the technological process. After each run of the same color, the auger is cleaned of old material. And this is precisely what affects the cost.

There are also two-tone yellow-green products. They are intended for grounding wires.

When you want to see and control the contacts after installation, a transparent tube will help you in this matter. Just be careful. Transparent ones will no longer be non-flammable products. Since the addition of fire retardants always leads to a change in color.

Therefore, self-extinguishing properties and transparency are not compatible here.

To apply inscriptions and mark wires, a piece of paper with numbers and symbols is often inserted under the transparent tubes. Once it shrinks, it produces an excellent permanent marking. This way you can indicate the brand of cable, its cross-section, what it powers, and much more.

True, in this case it is better to heat the transparent heat shrink with a hairdryer rather than with a torch. Otherwise, you may accidentally damage the inscription itself.

There are also semiconducting heat shrinks and equalizing electric field strengths.

But still, the usual electrical insulating ones are most often used. They use a material with high electrical insulating properties and have high electrical strength. Moreover, the higher this electrical strength, the higher the voltage class they are designed for: up to 1 kV-10 kV-35 kV.

Despite the fact that heat-shrinkable tubing was invented in the last century, it still remains an innovative product in the electrical market. You can select and order sets of thermal tubes for yourself.

Electrical wiring must be safe. This is one of the main conditions for its operation.

At the connection points, contact failure, overheating or even fire most often occur. Therefore, it is at these points that reliable insulation is especially important. Reliability can be ensured by insulating wires with heat shrink. This type of protection has many more advantages compared to other types of connection insulation.

What is Heat Shrink Tubing

(HERE) is a thin-walled tube made of polymer materials that can be compressed under the influence of high temperatures without collapsing. It is this type of tube that has found wide application in everyday life and is often used by home craftsmen.

Heat shrink for wires, the dimensions of which can change significantly when heated, is good because it fits tightly, without voids, at the junction of electrical wiring elements, and does not create unnecessary thickening, like, for example, ordinary electrical tape. However, this is not the only advantage of tubes made of polymer materials.

Benefits of Heat Shrinking

Heat-shrinkable tubing, compared to other methods of insulating conductive wires, has several more advantages.

Firstly, since it fits tightly, it does not move under various mechanical influences. Secondly, it is installed quite simply. Thirdly, after shrinking, the tube material becomes stronger, giving additional mechanical stability and rigidity to the place. In addition, it retains its properties for a long time, much longer than the same electrical tape.

Disadvantages of Heat Shrinking

The only drawback of heat shrink for wires, the dimensions of which change irreversibly when heated, is the impossibility of reuse after dismantling, since it is impossible to remove it without damage.

The price of heat-shrinkable tubing is higher than the price of regular insulating tape, but not so much as to become a decisive factor when choosing an insulating material.

Other possible shortcomings are, rather, shortcomings of a particular manufacturer.

Properties of Heat Shrink Tube

The main property of the tube, which determines its use, is the ability, by changing the diameter and thickness, to compress under the influence of high temperatures in the range of 80-120°C. Tubes whose initial heating temperature is not higher than 70°C are used in radio electronics.

It features a heat-shrinkable tube and a wide range of operating temperatures ranging from -45°C to +125°C. There are materials with even higher operating temperatures, up to 135°C. They are used in the automotive industry to insulate connections in the immediate vicinity of the engine.

The standard color is black, non-standard - red, green, blue, yellow, white. Transparent heat shrink tube is used in places where it is necessary to monitor the condition of the connection.

Main characteristics

Depending on the properties of the polymer, the ability to shrink, which characterizes heat shrink for wires, also changes. The dimensions of the tube can be reduced by half or even six times. The shrinkage ratio usually varies from 2:1 to 6:1.

Another characteristic is the presence of an adhesive layer. Heat-shrinkable adhesive tube is used in cases where contact connections need to be reliably sealed and protected from moisture and corrosion. In addition, hot melt adhesive on the inner surface of the tube gives additional strength to the connection.

Characterizes heat shrink tubing and resistance to light and aggressive environments. The material can be chemically or oil- and petrol-resistant, light-stabilized (resistant to ultraviolet radiation) or with a photoluminescence effect.

Heat-shrinkable tubes differ in polymer composition. They are made from PVC, polyolefins, elastomers and other materials, on which resistance to ultraviolet rays or fire, mechanical properties and color solutions depend.

For different connection requirements, tubes with similar characteristics can be produced, either in black or in transparent polyolefin. The color scheme is also a characteristic of heat shrink for wires.

Application area

Heat shrink tube (HERE) can serve not only to insulate the wires of an electrical circuit, although this is its main purpose.

It seals and protects against moisture, chemical corrosion, dirt and mechanical stress. The tube protects the wires from deformation and protects kinks.

It can be used to restore damaged insulation and sheathing of cables and wires, and to tie together bundles.

Heat-shrinkable tube, the dimensions of which allow you to put a small ring cut from it on wires of any thickness, comes in a large number of colors, so it is very convenient for marking. For example, a piece of red tube is placed on the end of the wire over the insulating layer, and this means “plus” in a DC electrical circuit. A black ring is installed on the minus, a yellow-green ring is installed on the ground, and red, yellow and green for the corresponding phases.

A thin heat-shrinkable tube that can withstand fairly high operating temperatures is convenient for repairing the on-board electrical network of a car, installing alarm systems, car radios and speaker systems.

Multi-colored tubes made of polymer materials are used for decorative purposes and for repairing household appliances and electrical wiring.

Heat shrink tubing sizes

All manufacturers label their products. The main parameter that distinguishes any heat-shrinkable tube is the diameters before and after shrinkage.

Usually the internal diameter before shrinkage is indicated first, and after the fraction - either the diameter or the coefficient by which it can be calculated. The most common is the standard 2:1 ratio.

Asian and Russian manufacturers produce tubes with a diameter that is a multiple of 0.5 mm or 1 mm. European manufacturers indicate diameters in inches, so when converted, the diameter is, for example, 1.6 mm or 4.8 mm.

If two tubes of similar diameters are suitable, you need to choose the larger one.

Heat-shrinkable tubing can be sold in one-meter pieces or, which is inconvenient for home use, in coils of 25, 50, 100 or more meters.

Types of Heat Shrink Tubing

Diameter before and after shrinkage and length are not all the geometric parameters that characterize a heat-shrinkable tube. Its dimensions also include thickness before and after heating.

The thickness of the tube can be divided into two types:

Thin-walled, the wall thickness of which after shrinkage does not exceed 1 mm. They are the most popular, including for household use. Colored, black and transparent tubes without an adhesive layer (shrinkage ratio from 2:1 to 4:1) are used not only for insulating wires, but also for marking. As a rule, they have heat resistance, a relatively low shrinkage temperature, increased resistance to sunlight and suppress combustion.

Thick-walled and medium-walled adhesive, the wall thickness of which after shrinkage is from 1.5 to 4.5 mm (shrinkage ratio from 2:1 to 6:1) are used for insulation and moisture protection of objects with a large difference in diameters, high-voltage cables, corrosion protection not only electrical contacts, but also steel pipes, sealing contact couplings.

Mechanical characteristics

Since the main task that a heat-shrinkable tube must perform is electrical insulation, the main characteristic is its dielectric strength, which must be at least 20 kV/mm. The strength characteristics of the material are also important. Tensile strength should not be less than 1.0 kgf/sq.m. mm (9.81 MPa), and the relative elongation is not less than 200%. The most durable is heat shrink for wires, the dimensions of which decrease six times when heated, its tensile strength is already more than 14.5 MPa.

In many cases, heat shrink tubing must ensure tight connections, so another characteristic is important - equilibrium water absorption. It should not exceed 0.2%.

Preparation for installation

The process does not require any special tools. You need a sharp knife or scissors to cut off the required pieces of tube without burrs and some kind of device for heating the tube. used by professional electricians who install a large number of connections. A home craftsman can easily make do with a gas torch or a regular lighter, the flame of which is quite enough to heat up the heat shrink for the wires.

Dimensions are more difficult to find. The initial diameter is important in order to fit the tube onto the wire connection without interference. The shrinkage factor or final diameter, which must be less than the diameter of the connection, must be known to ensure tightness and reliable protection.

And the greater the shrinkage, that is, the higher the coefficient, the greater the thickness of the tube, and therefore its strength after heating.

Heat shrink installation

So, a suitable thin-walled heat-shrinkable tube was selected based on its properties and dimensions. How to use it to insulate wires? First, you need to cut a piece from it so that it covers the length of the area that needs to be insulated, taking into account longitudinal shrinkage when heated. It is 5-10% and is also indicated by the manufacturer. There should be no burrs or deep damage on the cuts and surface of the cut tube so that the material does not collapse under the influence of high temperature.

First, the tube is put on the wire, then the connection is made on which it should be put on. After this, it is heated from one edge to the other, so that there is no large longitudinal shrinkage, or from the middle to the edges, if the section is long enough.

You cannot heat the tube at both ends at the same time - air bubbles may remain under it, which is undesirable, and wrinkles may form on the surface.

The tube must be heated evenly, making sure that there is no overheating, charring, ruptures or bubbles on its surface.

The temperature and heating rate are determined experimentally. There is no need to rush, especially if you have no experience in such work. Too high a temperature or heating rate may cause defects.

The work takes a little longer if the operating conditions require an adhesive heat-shrinkable tube. How to use it to seal a joint? First you need to prepare the wires or products to be joined: clean the sharp edges, clean and degrease the surfaces, as with normal gluing. The tube must be heated from the middle to the edges.

Heat shrink tube prices

It is impossible to name a specific price range. The cheapest heat shrink tube, the price of which is a little more than three rubles, is usually a black thin tube with a diameter of 2 mm, the shrinkage ratio of which is 2:1 and the wall thickness is 0.6 mm, made in Russia or China.

Prices depend on the manufacturer, size, presence of an adhesive layer, color, and other additional properties.

Thick-walled heat shrink for wires, dimensions 230x4.8 mm, with an adhesive layer, with a shrinkage ratio of 6:1, black from the world-famous German manufacturer ACS already costs more than 160 euros per meter.

It is not difficult to learn how to install heat shrink tubing at home. It can reliably protect wire connections, terminal installation locations and other elements. But this material can be used for a wide variety of purposes, as much as your imagination can handle. For example, for decorative finishing of metal products, rubberizing rollers or sealing holes during repairs.

Connecting conductors by twisting, soldering or crimping is an essential part of any electrical network. The quality of the connection determines the operation of electrical appliances connected to the network, as well as lighting. Modern manufacturers of electrical products are ready to present a large number of consumables, with the help of which the procedure for creating contact between wires can be carried out quickly and reliably.

All such methods involve applying a layer of insulation to prevent electric shock or short circuit. The most reliable method is still a cambric - a tube made of rubber or polyvinyl chloride, which is a reliable insulating material.

Details about cambric

To make it more clear, a cambric is a piece of tube made of materials with high resistance. Previously, such an insulator was produced only in solid form; now they use heat-shrinkable casings, which, under the influence of temperature, change their structure and decrease in size. In this case, the material reliably covers the junction of the conductors.

It is very convenient to use such tubes on wires with a large cross-section of conductors, especially when soldering or crimping with sleeves is used for connection. After finishing the work, it is enough to simply fix the cambric on the cable and, for greater reliability, grab it around the edges with a piece of electrical tape. In addition to its basic properties, cambric also prevents corrosion and prevents joints from oxidizing.

These tubes made of rubber and polyvinyl chloride have an affordable price; in addition to electrical engineering, they are used in many industries (for example, fishing). But it should be remembered that when working with cables or wires, you should purchase casings of the required diameter, otherwise the contact of the conductors will remain open, which will be a serious violation of electrical safety regulations.

What to choose: heat-shrinkable tube or PVC cambric

This choice must be made based on the situation in which electrical insulating materials will be used. For example, to prevent short circuits of several adjacent parts, heat shrink tubing is well suited. At high temperatures, it compresses the exposed parts of conductors and connections and has high resistance. The ability to shrink allows you to not choose the diameter of the heat shrink too precisely; it is enough to choose a few millimeters larger than the wire or cable itself.

The advantages of heat shrinkage include the following:

• a wide range of operating temperatures, which allows the use of heat-shrinkable tubing in various electrical networks;
• when burning or melting, heat shrinkage spreads fewer harmful toxic substances;
• has a long service life, much longer than ordinary insulating tape;
• does not interact with aggressive chemicals;
• is immune to oxidation and corrosion.

Modern heat shrinks are produced with a special substance applied to the inner surface. When heated, it exhibits high adhesive properties, as well as good tightness.

But ordinary cambric also has good electrical insulating properties. It is enough to select it correctly and put it on the joint. Can be used several times. Another significant fact is the low cost of this consumable.

The main advantages of using cambric

Cambric is a universal material that is suitable for all types of connections, as well as for open parts of cables and wires. What are the advantages of this type of insulation:

• Low cost, which makes it quite popular. But gradually more modern consumables are pushing these products out of the market.
• Versatility. It is enough to choose the correct diameter, and you can mount the cambric on any open current-carrying part.
• Long service life. If the connection of the wires (for example, by crimping with sleeves) is made correctly and there is no excessive heating of the conductors, then the cambric will last quite a long time.
• Reusable. For example, when dismantling an old shield, you can remove the cambrics and use them for their intended purpose in another place.
• Strength. The cambrics are quite durable, this allows you to put them on joints without worrying about the safety of the material.
• Can be used as a basis for marking conductors. To do this, you need to choose a light cambric, put it on the wire or cable, and sign it. Helps restore markings that have faded over time or been damaged during work.

Cambrides are a multifunctional consumable material for wires; due to the difference in diameters, they can be used not only for connecting conductors, but also for laying telephone lines and signal networks, where currents and voltages are small.

Heat-resistant fiberglass cambric

Another type of cambric is a heat-resistant material, which is more expensive and is not used as often as an ordinary PVC pipe. The increased cost of such consumables is due to the use of fiberglass in manufacturing. After creating the base layer, silicone varnish is applied to its surface. This increases the resistance of the product and improves its electrical properties.

Heat-resistant insulator is rarely used when installing electrical networks, more often when assembling automatic cabinets, induction ovens or drying chambers, as well as when connecting other heating devices. In addition to protecting the surrounding conductors, the heat-resistant cambric protects the connection from high temperatures.

Main performance characteristics of heat-resistant cambric:

• High electrical impermeability. This insulating material does not conduct electric current at all.
• The walls of the product are made with a thickness of 2.5 to 3 mm. This complicates the work a little, but becomes a serious obstacle to the path of electrical current.
• Does not burn. Able to withstand high temperatures.
• Wide selection of internal diameters of products (from 10 to 150 mm).
• Operating temperature limits: from –60 to +530 degrees. When exposed to cold, the structure of the cambric does not change.

Results

It is most convenient to use heat-shrinkable cambric for any type of wire connections.

The use of cambric, as well as heat-shrinkable tubing, is relevant for modern installation of electrical circuits. The low cost of such consumables makes the demand for it quite high, and the ease of use helps even people who have never dealt with electrical products to use the cambric. High resistance and immunity to fire make the cambric a reliable protective device for various types of connections and conductors.

Video on the topic