How to use shrink cambric. How to use a heat shrink tubing - the subtleties of the correct application HERE

There are several heating methods when working with heat shrink tubing HERE. Each of them can be applied with different kinds heat shrinkage, but some may not fit or even spoil the insulation.

The cheapest and most controversial option is matches. They are used when there is no other tool at hand, and heat shrinkage of very small sizes and sections. For large sizes, this is not the best option.

As a result, a not very neat shape of tube compression is obtained, and the whole process can take a long time if it comes about larger items. And how many matches are required if you need to isolate more than one connection, but several dozen?

A lighter in this matter is also not always an assistant.

In those rooms where it is impossible to use a flame or open fire, they try to adapt an ordinary hair dryer for drying hair. However, he is not able to create the required temperature for high-quality compression of heat shrinkage.

The optimum shrinkage temperature is from 90 to 140 degrees, depending on the brand of the product.

A household hair dryer has a low outlet temperature, just a few centimeters from the nozzle, it can give out about 70C. Narrow nozzles can help when heating small diameters, but the use of non-standard nozzles leads to the failure of the hair dryer itself. But there are thermotubes with a shrinkage of 350 degrees!

As a result, you may end up with an incompletely compressed or not completely insulated junction, where water will easily penetrate and moisture will be absorbed. Therefore, instead of using the tools at hand, try to always use a professional tool.

Tool for working with a tube HERE

In fact, there are 5 types of such a tool for heat shrinking in everyday life:

- high temperature building hair dryer (choice + order)
- portable butane gas-burners(you can buy)
- gas soldering irons(acquainted with current prices )
- propane burners
- infrared burners
  An industrial hair dryer is perfect tool for thin-walled tubes. He has in his assortment not only temperature control, but a variety of nozzles. You can choose the required set by following the link.
  
  Of course, if you are not the owner of a cordless tool, then you can work with a construction hairdryer only if you have a voltage of 220 volts nearby. Even the presence of a generator does not always guarantee normal work hair dryer due to its high power.
  Specifications
  
  This is its main disadvantage and inconvenience. In addition, it is not always possible to warm up thick-walled tubes even with a powerful hairdryer. The quality will clearly suffer here.
  
  Even before you start working with a hairdryer, you will have to hold the tube a little. Otherwise, a powerful jet of air can move it from its place. An infrared burner has an advantage in this case. It does not create air currents, and its rays warm up very quickly.
  
  Just be sure to keep in mind that dark tubes absorb heat much faster than light or multi-colored ones. Forgetting this can easily burn through the insulation.
  
  Gas burners have several flame functions. Heat pipes should be seated with a soft flame. How do you know if the flame is soft and suitable for shrinkage? It must contain languages yellow color... The same applies to gas-fired soldering irons.
  
  A propane burner is the only tool that is optimally suited for thick-walled pipes.
  
  When working with a burner or hairdryer, you must constantly make circular translational movements. Do not stop in one place, otherwise you can easily burn through the insulation.
  
  In general, the choice of shrinkage tool depends on the following parameters:
  - wall thickness
  - tube size
  - material from which they are made
  More details about these characteristics can be found in the article "10 types of heat shrink tubing."
  
  Heat Shrink Tubing Installation Guidelines
  
  There is no need to rush. First, the product warms up and shrinks around the entire circumference, and only then can you move forward gradually.
  - remember that the heat shrinkage is reduced not only in diameter, but also along the entire length
  The decrease, of course, does not occur by 2.3 times, but by several percent (maximum 15%). So do not be surprised if the tube HERE was originally 10 cm, and later became shorter by 1.5 cm. Therefore, when choosing the segments you need in size, always make a small margin.
  
  The reduction in length is especially noticeable when joining and insulating materials of different diameters.
  
  For some reason, everyone forgets to take into account the height difference in this case, and it also takes a decent margin.
  
  If you do not know for sure whether the selected size will be sufficient or not, then in this case it is better to ignore the above advice about starting the warm-up from the middle.
  
  Here, adhere to a different rule - heat the tube not from the middle, but from one end to the other. Thus, the longitudinal contraction of its length can be reduced.
  - when the heat shrinkage insulates any metal surface or a product with good thermal conductivity, you must first warm up this surface.
  In this way, the walls will stick together more tightly and so-called "cold scars" will be avoided. First of all, this concerns pipes of large diameters, without preliminary warming up, it is unlikely that it will be possible to avoid skewing.
  
  In addition, due to the temperature difference, condensation can form, which you "seal" directly onto the insulation. In general, any surface of the material must be cleaned and degreased before work. This is done with a cloth soaked in alcohol or solvent.
  
  If there are foreign sharp edges on the metal, then they must be removed and sanded.
  - when cutting and shortening the tube yourself, do it with a sharp knife, or better with scissors, so as not to leave burrs. After cutting, its edges should be smooth, only in this case the tube will be seated as tightly as possible.
  Of course, in this way you can increase its length by more than two times.
  However, at the same time, the thickness of the insulating wall also decreases by the same two times. And correspondingly dielectric strength will already be within smaller limits (for thin-walled it is usually 600V), and someday the phase will surely break through to the body or other vein.
  
  In addition, it decreases and mechanical strength... How long your connection will now last is a mystery. If, of course, you use this option for weak current, telephone cables or USB, then something may work. Plus, no one forbids putting on over the first layer in the same way, another stretched thermocambric.
  
  Likewise, some people manage to increase the width with round-nose pliers, expanding the tube while still cold.
  Thus, trying to make an analogue of expensive 4k1 out of cheap HERE 2k1.

Safety is one of the main requirements for electrical wiring... Overheating, fire, contact failure most often occur at the junction. Therefore, the insulation of the joints is important for a reliable and safe operation electrical networks. Ordinary insulating tape does not protect against prolonged exposure to moisture, the material of the fabric tape can deteriorate over time, the joint does not look very neat. Therefore, today an alternative to electrical tape is heat shrinkable tubing.

Heat Shrink Tubing Scope

Heat shrinkage before other insulation methods have several advantages:

tight fit eliminates displacement of insulation even with mechanical stress;
ease of installation;
additional mechanical strength;
durability.

The heat shrinkage is made from polymer material which shrinks when exposed to high temperature. After shrinkage, the tube tightly fits the junction, exactly repeating its relief, and forms a durable hermetic coating. Therefore, the main, but not its only purpose, is to ensure reliable insulation of the connections of current-carrying wires. In addition, heat shrink tubing serves for a few more purposes:

sealing and moisture protection;
protection against mechanical stress, dirt and chemical corrosion;
protection of places of bends and protection from deformation;
restoration of damaged insulation and sheaths of wires and cables;
tying harnesses;
color coding.

The use of colored tubing for marking is very convenient, a small ring of the corresponding color sits on top of the insulating layer at the end of the wire. For example, in the wires of the circuits direct current use red on the plus and black on the minus, in the ground wires - a yellow-green combined color, and in a three-phase circuit - red, yellow and green for the corresponding phases.

Large range of colors allows the use of heat shrinkage and as a decorative material.

In everyday life, heat shrinkage is used for repair home appliances, electrical wiring insulation. Due to its durability, a variety of sizes and the ability to work at high temperatures, it is very convenient when repairing an onboard electrical network and installation of alarms, radio tape recorders, car audio systems and on-board computers in the car. On foreign car brands, rigid heat shrink tubes are used for mechanical and corrosion protection of fuel lines and brake hoses.

Heat shrink tubing properties and characteristics

Shrink properties:

Main characteristics:

Shrinkage ratio from 2: 1 to 6: 1, that is, the ability to compress 2 - 6 times;
The presence of an adhesive layer, if reliable sealing, waterproofing and anti-corrosion protection of contact joints is required. A hot melt adhesive layer on the inner surface of the tube gives the joint additional strength and resistance to mechanical stress;
Resistant to aggressive environments. Heat shrinkage is chemically resistant, oil and petrol resistant, heat resistant, light stabilized, with the effect of photoluminescence;
The composition of the polymer. It can be polyolefins, PVC, elastomers and other materials on which the resistance to fire, ultraviolet rays, color solutions depends;
The color range in which the most common standard and combined options of two colors. Tubes with similar characteristics are often made of transparent polyolefin and in black with different connection requirements.

The process of installing heat shrinks is quite simple, and in everyday life you can do without special tool... You can heat the tube and regular lighter or a gas burner. Although, of course, industrial dryer allows shrinkage to be carried out neatly and evenly.

The whole difficulty lies in correct selection the size of the heat shrink tubing.

The initial internal diameter is always known, and the thickness of the tube and its shrinkage coefficient, that is, you can independently determine the diameter after shrinkage, although usually the geometric parameters before and after shrinkage are indicated by the manufacturer. You need to know the initial dimensions so that the tube fits on the wire or connector without tension. And in order to provide reliable sealed protection, the diameter of the heat shrinkage after heating must be less than the diameter of the connection of wires or the product that it protects. How more shrinkage tube, the greater its thickness after heating and the higher the strength.

By choosing a shrink of a suitable diameter, you need to cut a piece from it in such a way that it overlaps the length of the section that needs to be insulated with a margin for the longitudinal shrinkage of the tube. This indicator is also set by the manufacturer, and is usually 5-10%.

The cut must be smooth and the surface free of deep scratches so that the tube does not rupture due to high temperature in places where there are burrs and external damage.

When the tube is put on the section of the wire that is insulated, it is heated with a hot air gun or a lighter from the middle to the edges, if it is long or with an adhesive layer, or from one edge to the other, in the case when it is necessary to avoid large longitudinal shrinkage. If you start heating from both sides at once, air bubbles will remain at the junction and wrinkles will appear on the tube itself. You need to warm up the entire area evenly without overheating, so that there are no breaks, charring or bubbles on the heat shrinkage.

It is also important to be correct select heating temperature but this is already being determined empirically... The main thing is not to rush, the high temperature will not increase the shrinkage rate by much, but it will definitely lead to marriage, especially if the installer has no experience of such work.

If you need to insulate the joints with heat-shrink tubes with an adhesive layer, then the sharp edges on the product are cleaned, the surface is cleaned and degreased, then warmed up.

Heat Shrink Tubing Dimensions

Manufacturers always label the heat-shrinkable tubing. The main parameter is always the inner diameter before shrinkage. Sometimes the diameter after shrinkage is indicated through a fraction, and sometimes the coefficient by which the final diameter is calculated.

Standard and most the common ratio is 2: 1.

European manufacturers indicate the dimensions of the tubes in inches, and when converted to millimeters (1 inch = 2.54 mm), diameters of the type 1.6 mm, 12.7 mm are obtained.

Products of Asian and Russian manufacturers produced with diameters divisible by 0.5 or 1 mm.

As a rule, tubes are supplied in 1000 mm (one meter) threads. Although there are types of heat shrinks that are supplied in coils of 50, 100 or 200 meters.

You can almost always pick up two tubes of similar dimensions, in which case it is better to use a product with a larger diameter.

According to the thickness, heat shrinkage is divided into two types:

If you learn (and this is not difficult at all) to isolate connections in electrical circuits using heat shrink tubing, then you can quickly and reliably not only repair household appliances, but also to carry out more complex works on laying networks in a house or apartment.

A heat-shrinkable tube is a device that can change its diameter, shrink under the influence of high temperatures. In the process of shrinking, it will cover the object placed in it, and will provide protection: insulation and from mechanical damage. The scope of application of tubes is radio electronics, automotive, is used as an insulator of wires, for protection metal pipes from corrosion, as well as for antenna equipment.

Basic statements

If we speak in simple words, then heat shrink tubing (HERE) is a replacement for standard blue electrical tape. The only thing is that they cannot be used in areas with ornate bends and where there is different thickness in the course of "following".

Their main advantage is the ability to shrink when heated, it provides the necessary insulation and mechanical protection. The cost of the tubes is relatively low, the ease of use is ensured different colors, including the most common for cables - these are red, blue, green, yellow, striped. With the help of them, you can not only insulate, but also mark the wires to make it easier to further work with them.

I would like to dwell on the marking in more detail, since this is one of the important areas of use HERE. They are widely used when it is necessary to mark three-phase electrical circuits. They use red, yellow and green colors. By also marking the wires that correspond to a certain phase, you can facilitate the operation process. The standard option for grounding is yellow-green stripes.

Material characteristics

Before using HERE, you need to choose the right ones, and for this you need to know the main characteristics. These include:

Shrinkage - this ratio ranges from 1: 2 to 1: 6.
Adhesive layer.
The composition of the tube can be PVC, polyolefin, elastomer, fluoropolymer.
Color - one-color, combined.

And, also resistance to such influences - temperature, chemical exposure, light stabilization, resistance to petroleum products.

There is also a division according to the strength of the walls of the tube, according to this indicator, HEREs are thick-, medium- and thin-walled. The first two types are combined into one group and are characterized by a wall thickness of 1.5-4.5 mm, which it will become as a result of shrinkage. In this case, the indicators vary from 2: 1 to 6: 1. It is in them that there is an adhesive inner layer.

Thin-walled can be transparent or colored, with a wall thickness of up to 1 mm after shrinkage, the ratio of contraction is from 2: 1 to 4: 1. Used as insulators and markers. They often have special characteristics, among them:

Self-extinguishing.
No halogen emissions on fire.
Heat resistance.
Reduced heat shrink temperature.
Improved UV resistance.
Resistance to mechanical and chemical influences.

When denoting the size of the tube, manufacturers indicate two numbers through a fraction: one is the diameter before shrinkage, the second is after. Additional markings can indicate the color and length of the cut.
When you choose HERE, it is important to consider that its diameter must be larger than that of the product for which it will be used. For shrinkage to occur correctly, its diameter after shrinkage should be slightly less than the diameter of the product on which it is mounted.
Before using HERE, you need to inspect it for damage and burrs. If there are scratches or burrs, it is better to refuse to use such tubes.
If you plan to use HERE with an adhesive layer, then the surface on which they will be seated must first be cleaned and degreased. To avoid damage to the tube, there should be no places on the product that could be potentially dangerous for HERE. If there are sharp edges, they need to be sanded and smoothed.

First you need to prepare the tools. For this, any sources that will give the required heat flux are suitable. The minimum temperature should be +70 degrees. The required indicators are indicated when marking. It depends on the type of tube: for thick-walled, the temperature should be higher, for thin-walled - lower. If you plan to use a building hair dryer, then the requirements for it are identifying the required temperature. If you are using gas burners, it is important that they have a soft yellow flame. Options for use as a heat source can be matches, lighters.

Shrinkage technique:

Surface preparation, which includes degreasing, cleaning and heating. For this, sandpaper or a solvent-soaked rag can be used, depending on the material.
The choice of the tube in accordance with the requirements, its heating, which is especially important for thick-walled tubes. It must be warmed up without placing it on the place of "permanent residence" and not to the maximum temperature, but by half, that is, if the temperature of complete shrinkage is 120 degrees, then it must be warmed up to 60.
Next, the tube is pushed onto an insulated object, a surface. On heating device set the required temperature.
Shrinkage should be started from the middle. After even sitting down in the center, you should move to the right and left.
It must be heated evenly by moving the heat source along it, this will not allow local overheating, and therefore damage HERE.
If there is glue on the inner surface, it should leak out as a result of shrinkage. After shrinkage, the item must be left alone until it cools completely.

Application HERE is a modern and convenient solution... To experience the full benefits of this insulator, you need to use it correctly. We tried to explain in as much detail as possible everything you need to know for the successful application of HERE.

Video: how to use the heat shrink tubing

A heat-shrink tube (HERE) is a part that, under the influence of high temperatures, narrows and wraps around the part tightly. This property is provided by specifications polymers, which serve as the main material for the manufacture of shrink tubes.

Specifications

When choosing a heat shrink tube, you need to focus on the following indicators:

shrinkage capacity (from 1: 2 to 1: 6);
the presence of a layer of glue on the inner surface;
material from which HERE is made;
Colour.

If you plan to use the part after shrinkage in extreme conditions, you must take into account its susceptibility to high and low temperatures, impact chemical substances and direct sunlight.

Heat shrink tubing has the following advantages:

do not light up or immediately fade out on their own;
serve long enough;
do not require special skills to use;
well resist adverse influences.

Comparing insulating tape and heat shrinkage, it is worth noting that the tape can unwind over time and leave a layer of glue on the insulating material. The pipes look more aesthetically pleasing and are easier to remove by simply cutting them lengthwise.

Manufacturers make straws different shapes, with thick and thin walls, suitable for use in various conditions.

How to use heat shrink tubing

Heat-shrinkable tubes are indicated by two numbers separated by a fraction, it is important to know what they mean. The first is the diameter before shrinkage, the second is after. The dimensions of the tube itself and its color can be indicated next to it.

For the right choice you need to be guided by the following rule: the diameter of the purchased tube should be wider than that of the wire or part on which it will be put on, and the diameter after shrinkage should be narrower. This is the only way to ensure high-quality insulation.

If heat shrinkage is required with a layer of glue inside, it is important to thoroughly degrease the wire or part before use, otherwise the tube will not stick. The surface must be removed from sharp edges that will damage HERE. Do not use heat shrink tubing that has holes or burrs.

Before you ask yourself how to use heat shrinkage, you first need to prepare tools that will heat the polymer surface. The temperature should not be lower than +70, otherwise the heat-shrinkable tube will not shrink tightly and evenly. You can apply:

construction hair dryer;
gas-burners;
lighters, etc.

The temperature required for shrinkage is indicated on the label.

Experts, when telling how to work with a heat shrink tubing, recommend focusing on the following steps:

The tube is put on the wire and moved away from the place where the wires are connected. They must first be twisted together, then you can install the tube so that the joint of the wires is in the middle of its length.
Warming up and shrinkage. Once the heat shrink is installed, you can start heating it. Warming up starts from the middle, then you can gradually move to the edges. The temperature must not be exceeded in any areas, otherwise the tube will sit unevenly. If there was a layer of glue inside, then when heated, it will flow out from the edges.
Cooling down. As long as the heat shrink is warm, it should not be touched.

Applications

What is a heat shrink tubing for? Heat shrinkage is necessary for high-quality insulation of joints electrical wires and parts of conductors. In addition to wires, it is used for rust protection and waterproofing. For this purpose, a special layer of glue is applied to the inner part of the heat shrinkage, allowing it to be attached to metal or wood.

The wide color range allows the use of heat shrink tubing not only for protection or insulation, but also as a marking for electrical cables or wires. The following designation is adopted for the components of a three-phase network:

phase A is marked in yellow;
B - green;
C - red.

A ground contact is usually indicated in yellow-green.

Due to its ease of use and durability, heat shrink tubing has become an excellent and reliable alternative to outdated electrical tape.

Heat shrink tubing is used to seal, label and insulate cables, wires and other similar components. Heat shrinkable insulation it is distinguished by its compactness, aesthetic and professional appearance. When seated, the tube retains its shape and fits snugly to wires, terminal blocks and connectors. When overheated, the heat shrinkage is not destroyed, retains its properties and becomes soft.

Depending on the application, heat pipes have different characteristics:

shrinkage factor;
wall thickness;
adhesive composition.

Colored and thin-walled shrink tubes

Colored, transparent and black thermotubes with a wall thickness of less than 1 millimeter after shrinkage are used for marking and insulating wires. Their shrinkage ratio ranges from 2 to 1 to 4 to 1.

Special properties of the tubes:

heat resistance;
self-extinguishing;
UV resistance;
low shrinkage temperature;
zero emission of halogens during combustion;
resistance to mechanical and chemical stress.

Thin-walled tubes do not contain an adhesive layer.

Medium and thick wall heat pipes

Specifications:

wall thickness - 1.5-4.5 mm;
shrinkage factor - from 2 to 1 to 6 to 1;
hot glue is applied to the inner surface.

For isolation power cables with a medium voltage level, thermotubes with specified chemical and dielectric properties, for example, track resistance, are used. Tubes are mounted using sealing and insulating mastics.

The principle of working with thermotubes is quite simple, but there are certain nuances that a novice electrician needs to know:

1. The size of the shrinkage tubes is denoted by a fraction, where the numerator contains the initial diameter, and the denominator, respectively, the diameter after shrinkage. Additionally, the color and length of the segment are indicated.

2. The initial diameter of the heat pipe must be larger than the diameter of the product on which it will be put on. For a snug fit, after heat shrinking, its dimensions should be at least a little smaller sizes products.

3. The stronger the shrinkage, the thicker the tube walls will be.

4. Longitudinal shrinkage in length is 5-10 percent.

5. There should be no burrs at the ends of the tubes, and deep scratches and other damages on the surface.