Heat shrinkage for wires and its use as an insulating material

The heat shrinkage for the wires serves as an insulator in live areas. Its use allows you to secure the process of using electricity in buildings in the residential, industrial and commercial sectors. This article will help you figure out which version of the heat shrink tubing is best for insulating wires and how to install it correctly. The text contains information on characteristics, average prices, as well as recommendations for the selection of products.

Heat shrinkage for wires is an insulator and is able to secure the process of using electricity

What is heat shrinkage: its purpose, advantages and disadvantages

A heat shrinkable tube (heat shrink) is a plastic product with insulating properties. For manufacturing, raw materials with thermoplasticity are used. When heated, such materials become practically liquid. As they cool, they turn into a stretching mass and solidify.

The heat shrink tubing shrinks and takes on the shape of the object it is worn on

Thermoplastic types of plastics include:

• polyester;
• polyethylene;
• fluoroelastomer, etc.

Thanks to these properties, it is possible to give any shape to the heated product, which will retain it after cooling, which has greatly expanded the scope of application of heat shrinkage. The installation system is pretty simple. To do this, you need to put the product on a section of a wire or other piece of equipment that needs insulation, and then heat it up.

Under the influence of temperature, the size of the heat shrink tubing decreases, it shrinks and takes the shape of the object on which it is worn. All that remains is to wait until the product hardens. For heating, a building hair dryer or burner is usually used.

Note! An open flame may be used to heat the heat shrink tube, unless prohibited by safety regulations.

A heat-shrinkable tube is a plastic product that, when heated, turns into a stretching mass, and hardens as it cools

Scope and purpose of heat shrink tubing

Heat shrink properties such as elasticity, elongation, resistance to aggressive chemicals and high tensile strength have determined their field of application.

Heat shrinkage is mainly used in the power industry to perform the following tasks:

• insulating wires, as well as current-carrying parts of electrical equipment;
• protection of areas where cable lines are connected;
• installation of lugs and couplings on wires;
• cable marking.

The main purpose of heat shrinkage is to insulate wires and live parts of electrical equipment

In addition, heat shrinks have found useful industrial applications. They are actively used in the chemical, automotive and other industries.

With heat-resistant insulation for wires, you can:

• repair broken machine parts;
• protect various structural elements from aggressive environmental influences, for example, corrosion, as well as chemically active substances;
• protect parts from high temperatures;
• process locksmith tools, for example, wrenches or screwdrivers, to ensure their safety (creating an insulating coating);
• protect from abrasion areas that are constantly exposed to mechanical stress (areas where the mechanisms of the structure and its units are in contact).

Heat shrink tubing on automotive spring to protect it from corrosion

Comparative characteristics of heat shrinkable tape and tubing

Heat shrinkage, like any other type of insulating material, has advantages and disadvantages, which determine how convenient and useful it will be to use the product in a certain situation. To prevent short circuit and fire in a place where wires are connected, usually an electrical tape or a protective tube is used. It is possible to determine which version of the product is better only by comparing their pros and cons.

Useful advice! If heat shrink tubing is used as insulating tool, it is better to use products with a corrugated or ribbed surface for this purpose. They will not only improve the ergonomics of the handles, but also provide a more secure grip.

Comparative characteristics of electrical tape and heat-shrinkable tube:

Heat shrinkage for wires: product classification

The existing range of shrink sleeves can be divided into several categories.Products are classified according to the following criteria:

• material of manufacture;
• geometric parameters (wall thickness and diameter);
• installation method;
• shrinkage degree;
• form;
• accessibility, etc.

Heat shrinkage is classified according to the following characteristics: material of manufacture; wall thickness and diameter, installation method, degree of shrinkage and shape

The shape of the heat shrink tubing is oval, round and flattened. This parameter is selected taking into account the method of storage and transportation. Oval and flat products are tubes with a large diameter or thin walls. Round heat shrinks usually have thick walls. Small diameter tubes are sometimes found among them. Round shrink sleeves have an adhesive layer.

Note! The performance of the insulation is independent of its shape.

Classification of heat shrink tubes by material type

Industrial enterprises produce a large number of polymeric materials with thermoplastic properties:

• polyvinyl chloride;
• polyester;
• fluoroelastomer;
• polyethylene;
• polyvinylidene;
• polyethylene terephthalate;
• polymers containing polyolefin.

This raw material is used to varying degrees in production in the process of manufacturing heat shrinkage.

In the process of making heat shrinks, raw materials such as polyvinyl chloride, polyester, fluoroelastomer, polyethylene, polyvinylidene can be used.

Polyolefin heat shrink - insulation for wires, consisting of cross-linked polyethylene. Before use, the raw material is subjected to radiation and chemical treatment. In addition, manufacturers include flame retardants and pigment components in the material. This type of tube is considered to be the most common. The working temperature range of polyolefin insulation is from -50 ° C to +150 ° C. Heat shrinkage easily tolerates contact with oxidants and benzene, and fuels and lubricants destroy its structure with prolonged interaction.

Elastomer is a material based on artificial rubber. Such tubes are not afraid of the influence of fuels and lubricants, as well as high temperatures (the upper limit is +170 ° C). The cost of such products is quite high.

A material such as polyester is used to produce large diameter heat shrink tubes with thin and ultra thin walls. At the same time, the resulting products, despite their small thickness, withstand mechanical stress and exposure to chemicals well.

Products made on the basis of silicone are flexible, have a high safety factor and chemical inertness. The material contains no toxic components. Silicone insulation is degraded by organic solvents.

Silicone-based heat shrink tubing has high flexibility and a large margin of safety

Fluoroplastic insulation has unique performance characteristics. The manufacturing process of these products is rather complicated, so their cost is very high.

Insulating tubes made of thermoplastic polyvinyl chloride have a limited operating temperature range - from -20 ° C to +80 ° C.

Note! Thermoplastic polyvinyl chloride belongs to the category of combustible materials. During combustion, it releases harmful substances.

Types of products by installation method: heat shrinkage with and without an adhesive layer

According to the method of installation, glue and glueless products are distinguished. In heat shrinks, which are installed without glue, the tightness and strength of the connection completely depend on the tightness of the grip and pressure.

Heat-shrinkable tubes are divided into glue and glue-free products according to the installation method.

Heat-shrinkable wires with adhesive provide a stronger and more secure connection. In these products, the inner surface is treated with a thermosetting adhesive.After the tube is installed, this substance ensures the tightness of the connection, and the heat shrinkage itself decreases in diameter by about three times.

In addition, there are products with additional longitudinal sealing, for example, Deray Duomelt 105. They have the form of a two-layer melted tape coated with butyl rubber mastic. The tapes are used not only to seal cables, but also to reduce sound impact, as well as moisture protection.

How to use the tape shrink? You will need to do the following:

1. The fusible tape is used in conjunction with the tubes of the same company.
2. It is placed inside the wiring harness in the area where the heat shrink will be installed.
3. When the tube heats up, the tape melts and fills the voids inside the bundle between the wires.

Adhesive shrinkable wire shrinks provide a stronger, more air-tight connection

Thanks to the molten tape, the wiring is reliably protected from moisture, condensation, dust and even air.

Features of Glue and Solder Heat Shrink Tubing

The category of adhesive products includes heat shrinkage for soldered wires. These tubes have red rings. These pigmented areas are thickened heat shrinks with an adhesive layer. During the heating process, the red rings are compressed and securely fixed over the insulating sheath of the wire. This protects the connection from moisture penetration, and also reduces the likelihood of rupture.

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Solder with flux is located between the rings. To melt this material, a relatively small temperature effect is required - +120 ° C. The diameter of the heat shrink tubing may vary at different ends. Manufacturers color-coded products to make it easier for buyers to select the conductor sleeve.

Solder Wire Heat Shrink Size Chart:

Note! There are a few things to consider before heating the heat shrinkage for solder wires. If you use a lighter, the connection will be covered with soot, but the fixation will turn out to be very reliable. The hair dryer retains its aesthetics and holds the wires well. However, such a connection will not be able to withstand frequent bends.

Varieties of connectors for auto wires with heat shrink

The filling of modern cars includes many electronic and electrical components. To ensure reliable and stable operation of the equipment, all connections must be strong and of high quality. This can be achieved by using heat shrink wire insulation. Products have unique properties, therefore 50% of products manufactured by European manufacturers are used in the automotive industry.

Using insulation for wires with heat shrinkage, you can ensure reliable and stable operation of electrical equipment in the car

This category of connecting elements includes adhesive and glueless heat pipes for insulating wires, as well as heat shrinkable products:

• terminals;
• crimp sleeves;
• tips with glue tube;
• cable gloves;
• caps and end fittings;
• couplings.

All of them can be combined with thermo- and non-thermoplastic adhesives and sealants.

With the help of connectors for wires with heat shrinkage, it is possible to protect the connection points from mechanical stress, as well as provide good electrical insulation. In automobiles, such products are used to splice cables, leads and contacts, as well as some components of the electric motor, starter and generator. Heat shrinks have dielectric properties.A large range of sizes allows the buyer to choose a product to protect any harness or wire in the car.

Wire insulation tubes can be used to seal connectors and connections. Due to the fact that modern car manufacturers have increased the service life of the engine, as well as the operating temperature in its compartment, rubber fittings, as well as the technology of spraying plastic over the mold, cannot exclude the possibility of moisture getting to the joints. Heat shrinking for cables with high compression ratio successfully cope with this task. In such products, the amount of adhesive is usually increased.

Heat-shrinkable connectors for auto wires protect the joints from mechanical stress and provide excellent electrical insulation

There are also products on sale that are used to seal a whole bundle of wires. They are thermoplastic tubes combined with profiles and adhesives (sealants).

Note! If the tube will be placed in the engine compartment, it is advisable to use a product that is designed for operation in conditions of +135 ° C or more. For wires in the trunk and interior of the car, such characteristics are not required.

Wall thickness and dimensions of heat shrinkable wires

When choosing a heat shrinkage for sealing wires, it is imperative to take into account the diameter and other dimensional parameters of the tubes. All manufacturers label their products. Moreover, the bore (inner) diameter is usually indicated on the products, so there is no need to independently calculate the proportions during compression.

The markings on the tubes are as follows:

• the abbreviation "HERE" indicates that this product is heat-shrinkable;
• the fractional number reflects the diameter of the product before shrinkage (first value) and after it (second value);
• the numbers that follow the fraction correspond to the thickness of the shrink.

The diameter of the heat shrink tubing can vary between 0.2-20cm

Sometimes the product name contains additional notes. For example, ng means the tube is self-extinguishing.

Shrinks can have other properties:

• high voltage (some products can withstand high voltage - up to 1000 V);
• oil resistance;
• light stabilization (resistance to direct sunlight);
• resistance to chemical environment;
• heat resistance (there is no such quality as flammability).

The diameter of the heat shrinkage can be varied. It is selected taking into account the size of the cable where the product will be installed. The diameter of such tubes can vary from 0.2 to 20 cm.

Products are delivered to stores in slices or in coils (flat versions of products). Depending on the diameter of the tube, the length of the heat shrinkage in one coil can be 10-100 m. Cut products usually have a length of 1 m. As for the heat shrinkage with an adhesive layer, the size of such tubes is standard - 1.22 m.

Adhesive and thick-walled heat shrinks provide a waterproofing coating with a thickness of 1 to 4 mm

Note! Tubes with thick walls or with an adhesive layer should not be bent as they may break. Therefore, products of this type are sold not in coils, but in slices.

The dimensional parameters of products include such characteristics as the shrinkage coefficient. It varies between 200-600%. Under the influence of temperature, the tube shrinks and decreases in diameter. This nuance must be taken into account when choosing a product for installation.

For thin-walled tubes and glueless products, the shrinkage ratio is usually 4: 1. As a result, a 1 mm thick insulating joint is formed on the wire. Thick-walled and adhesive heat shrinks form a waterproofing coating on the surface with a thickness of 1 to 4 mm. The compression ratio in such products is 6: 1.

Buying heat shrink tubing: product prices

Heat shrink tubing is found in the assortment of any hardware store. They can be ordered on the Internet, purchased from specialized organizations that deal with low-current communications and solve power supply issues, in electrical and lighting stores.

Products are delivered to shops in slices or in bays of 10-100 m

The following firms are among the most demanded manufacturers:

• LG;
• Zeux;
• DAG-Canusa;
• Sumitomo;
• 3M;
• Raychem.

However, the cost of branded products is quite high, so not all buyers can afford it. Termoform, Metatron and TMARK are popular among Russian brands.

Different types of heat shrinkage prices:

Helpful advice! To insulate connections on harnesses, power cables and pipes, it is best to use heat shrinks with a compression ratio of 6: 1.

How to use heat shrink tubing: installation process

Before proceeding with the installation of the heat shrink, it is necessary to carry out a number of preparatory work.

Before proceeding with the installation of the heat shrink, it is necessary to choose the right tube and prepare the appropriate tool

At this stage, the following operations are required:

• choose a tube of the appropriate type and size;
• determine the amount of material required for work;
• prepare the tool.

In addition to a hot air gun for heat shrinking, you can use other tools, such as a gas soldering iron or a portable propane torch. An infrared burner is also suitable for this purpose.

How to use the heat shrink for wires? This requires:

• Clean the surface of the wires from dirt and debris.
• Cut a piece of tubing to the desired length.
• Apply heat shrink to the section of the wire where the connection is made.
• Using the selected tool, heat the tube along its entire length.

In addition to the construction hair dryer for heat shrinking, you can use a gas soldering iron, a propane torch and even a lighter

The process of installing heat shrinkage is simple, so any person can independently perform this procedure. If a long piece of large diameter is used for insulation, it should be heated in the direction from the middle to the edges, having previously carried out the upsetting of the tube around the circumference.

If the installation of heat shrinkage will be carried out on a metal base with a high thermal conductivity, such a surface must be preheated. If there are sharp edges in the connection zone, they need to get rid of them, otherwise, as a result of shrinkage, punctures will form on the insulation. You should not stretch the product if its length is not enough to cover the connection area, since this will negatively affect the dielectric properties and strength characteristics of the heat shrinkage.

Heat shrink tubing reliably protects electrical connections. Heat shrinkage as a method of insulation has many advantages, therefore it is very popular.