Table of Contents
Thermoshrinkage for wires serves as the insulator on current carrying sites. Its application allows to secure process of operation of electricity in buildings of inhabited, industrial and commercial sectors. This article will help to understand what option of a thermoshrinkable tube it is better to use for isolation of wires and as it is correct to establish it. The text contains information on characteristics, average quotations and also recommendations about the choice of products.
What is thermoshrinkage: its assignment, advantages and shortcomings
The thermoseated tube (thermoshrinkage) is a plastic product with the isolating properties. For production the raw materials having thermoplasticity are used. When heating such materials pass practically into a liquid form. In process of cooling they turn into the lasting weight and harden.
Carry to thermoplastic types of plastic:
- fluoroelastomer, etc.
Thanks to these properties it is possible to give any form to a heated product which will keep it after cooling that has substantially expanded scope of thermoshrinkages. The system of mounting is quite simple. For this purpose it is necessary to put on a product the site of a wire or other component of the equipment which needs isolation, and then to heat it.
Under the influence of temperature the size of a thermoshrinkable tube decreases, it contracts and takes the form of an object which it is put on. It will be necessary only to wait until the product hardens. For heating the construction hair dryer or a torch is usually used.
Pay attention! For heating of a thermoshrinkable tube application of an open flame is allowed if it is not forbidden by safety instructions.
Scope of application and purpose of thermoshrinkable tubes
Such properties of thermoshrinkages as elasticity, ability to lengthening, resistance to aggressive influence of chemicals and high rate of tensile strength, have defined the field of their application.
Thermoshrinkages are mainly used in power for performance of such tasks:
- isolations of wires and also current carrying parts of electric equipment;
- protection of sites where cable lines connect;
- installations of tips and connection sleeves on wires;
- markings of cables.
Besides, thermoshrinkages have found useful application in the industry. They are actively used in chemical, automobile building and other industries.
By means of heat-resistant isolation for wires it is possible:
- repair the failed machine components;
- protect various constructional elements from aggressive influence of the external environment, for example, of corrosion and also chemically active agents;
- protect parts from influence of high temperatures;
- process the bench tool, for example, fork spanners or screw-drivers to secure their operation (creation of an insulating cover);
- protect from abrasion of a zone which constantly are exposed to mechanical loadings (sites where mechanisms of a design and its knots adjoin).
Comparative characteristic of a thermoshrinkable insulating tape and tube
Thermoshrinkage, as well as any other type of the isolating material, has advantages and shortcomings on which depends how convenient and useful will be use of a product in a certain situation. To prevent short circuit and ignition in the place where wires connect, the insulating tape or a protective tube is usually applied. Define what option of a product is better, it is possible only when comparing their pluses and minuses.
Helpful advice! If the thermoshrinkable tube is used as isolation of the tool, it is better for these purposes to use products with a corrugated or ridge surface. They not only will improve ergonomics of handles, but also will provide more reliable capture.
Thermoshrinkage for wires: classification of products
The existing range of thermoshrinkages can be separated into several categories.
Products are classified by such signs:
- to production material;
- to critical bucklings (thickness of a wall and diameter);
- to mounting mode;
- extents of shrinkage;
- to form;
- to special opportunities, etc.
In a form thermoshrinkable tubes are oval, round and flattened. This parameter is selected taking into account a way of warehousing and transportation. Oval and flat articles represent the tubes having the large diameter or thin walls. At round thermoshrinkages usually thick walls. Among them tubes sometimes meet small diameter. Round thermoshrinkages have a glue layer.
Pay attention! A performance of isolation does not depend on its form.
Classification of tubes thermoshrinkages as material
The industrial enterprises release a large amount of the materials of polymeric origin having thermoplastic properties:
- polymers incorporating polyolefin.
These raw materials are in a varying degree applied on production in the course of production of thermoshrinkages.
Polyolefin thermoshrinkage – the isolation for wires consisting of the sewed polyethylene. Before use raw materials are exposed to radiation and chemical treatment. Besides, producers include burning inhibitors and also pigmental components in composition of material. This type of tubes is considered the most widespread. Operating range of temperatures of polyolefin isolation – from -50 °C to +150 °C. Thermoshrinkage quietly transfers contact with oxidizers and benzene, and fuels and lubricants in long interaction destroy its structure.
Elastomer – material on the basis of the rubber received in the artificial way. Such tubes are not afraid of influence of fuels and lubricants and also high temperatures (the upper bound makes +170 °C). The cost of similar products is quite high.
From such material as polyester, thermoshrinkable tubes of large diameter with thin and superthin walls are made. At the same time the received products, despite small thickness, well maintain mechanical loadings and influence of chemicals.
The products made on the basis of silicone have flexibility, high margin of safety and chemical inertness. As a part of material there are no toxic components. Silicone isolation decays under the influence of solvents of organic origin.
Ftoroplastovy isolation has a unique performance. Process of production of these products is quite difficult therefore their cost is very high.
Insulating tubes from thermoplastic polyvinylchloride have limited operating temperature range – from -20 °C to +80 °C.
Pay attention! Thermoplastic polyvinylchloride belongs to the category of combustible materials. In the course of burning it emits harmful substances.
Types of products on a mounting mode: thermoshrinkages with a glue layer and without it
On a mounting mode distinguish glue and glueless products. In thermoshrinkages which are established by a glueless way the tightness and durability of connection completely depend on density of a grasp and pressure.
Thermoshrinkages for wires with glue provide stronger and reliable fixing of connections. In these products the inner surface is processed by thermosetting glue structure. After the tube is established, this substance provides tightness of connection, and thermoshrinkage decreases in the diameter approximate three times.
Besides, there are products with additional longitudinal sealing, for example, of Deray Duomelt 105. They have an appearance of the two-layer fusible tape covered with butylrubber mastic. Tapes are applied not only to sealing of cables, but also to reduction of sound influence and also moisture protection.
How to use thermoshrinkage in the form of a tape?
It will be required to perform the following operations:
- The fusible tape is applied together with tubes of the same firm.
- It is located in a wiring plait in that zone where thermoshrinkage will be established.
- When heating a tube the tape melts and fills emptiness in a plait between wires.
Thanks to the melted tape wiring is reliably protected from hit of moisture, condensate, dust and even air.
Features of thermoshrinkable tubes with a glue layer and solder
Thermoshrinkages for wires with solder belong to the category of glue products. On such tubes there are red rings. These pigmented sites are reinforced thermoshrinkages with a glue layer. In the course of heating red rings contract and are reliably fixed over an insulating cover of a wire. At the expense of it protection of connection against moisture penetration is provided and also gap probability decreases.
Between rings solder with gumboil is located. Melting of this material requires rather small temperature influence – +120 °C. Diameter of a thermoshrinkable tube on the different ends can differ. Producers mark products with color marking to facilitate to buyers selection of a sleeve for the conductor.
The size table of thermoshrinkages for wires with solder:
Mm cable cross-sectional area ², Colour of marking, diameter of a sleeve
- Through passage of mm
- 0.3-0.5 White 1,5
- 0.5-1 Red 3
- 1-2.5 Blue 5
- 4 Yellow 6
Pay attention! Before heating thermoshrinkage for wires with solder, it is necessary to consider several moments. If to use the lighter, the junction will become covered by a soot, however fixing will turn out very reliable. The construction hair dryer keeps esthetics and well fixes wires. Nevertheless such connection will not be able to sustain frequent bends.
Kinds of connectors for car wires with thermoshrinkage
The stuffing of modern cars includes a set of electronic and electric components. To ensure reliable and steady functioning of the equipment, all connections should be strong and qualitative. Such result can be achieved, having used isolation for wires with thermoshrinkage. Products have unique properties therefore 50% of the products which are turned out by the European producers are involved in automotive industry.
This category of feature connectors has included glue and glueless thermotubes for isolation of wires and also thermoshrinkable products:
- blooming sleeves;
- tips with a glue tube;
- multiple cable joints;
- caps and end fitting;
All of them can be combined with thermoplastic and not thermoplastic glue structures, but sealants.
By means of connectors for wires with thermoshrinkage it is possible to protect places of connections from mechanical influence and also to provide good electrical insulation. In cars such products are used for merging of cables, conclusions and contacts and also some components of the electric motor, the starter and the generator. Thermoshrinkages have dielectric properties. The big dimensional ruler allows the buyer to pick up a product for protection of any plait or a wire in the car.
By means of tubes for isolation of wires it is possible to pressurize connectors and connections. Because producers of modern cars have increased engine service life and also working temperature in its compartment, rubber shaped parts, as well as technology of sputtering of plastic over a compression mold, cannot exclude the probability of hit of moisture to places of joints. With this task thermoshrinkages for cables successfully cope with high coefficient of compression. In such products the number of glue structure is usually increased.
On sale the products applied to sealing of the whole wire bundle also meet. They represent the thermoplastic tubes combined with profiles and glue structures (sealants).
Pay attention! If the tube is placed in engine compartment, it is desirable to use a product which is designed for operation in the conditions of +135 °C and more. For wires in a luggage carrier and salon of a car such characteristics are not required.
Wall thickness and the amount of thermoshrinkages for wires
Selecting thermoshrinkage for sealing of wires, it is necessary to consider diameter and other dimensional parameters of tubes. All producers mark the products. And on products (internal) diameter through passage therefore there is no need independently to calculate proportions at compression is usually specified.
Marking on tubes looks as follows:
- fraction reflects diameter of a product before shrinkage (the first value) and after it (the second value);
- digits which follow fraction correspond to thermoshrinkage thickness.
Sometimes the name of a product contains additional marks. For example, that the tube does not sustain combustion.
Thermoshrinkages can have also other properties:
- high voltage (some products are capable to sustain influence of high tension – to 1000 V);
- oil resistance;
- light stabilization (resistance to influence of direct sunshine);
- resistance to the chemical environment;
- thermal stability (there is no such quality as combustibility).
Diameter of thermoshrinkages can be various. It is selected taking into account the cable size where the product will be established. Diameter of such tubes can vary within 0.2-20 cm.
The products come to shops in cutting or in bays (flat options of products). Depending on diameter of a tube, thermoshrinkage length in one bay can be 10-100 m. Products in cutting usually have length of 1 m. As for thermoshrinkages with a glue layer, the size of such tubes standard – 1.22 m.
Pay attention! Tubes with thick walls and also with a glue layer it is impossible to bend as on them breaks can appear. Therefore products of this kind are on sale not in bays, and in cutting.
It is possible to refer to dimensional parameters of products also such characteristic as shrinkage factor. It varies within 200-600%. Under the influence of temperature the tube takes seat and decreases in the diameter. This nuance should be considered, selecting a product for installation.
At thin-walled tubes and also glueless products the shrinkage factor is usually equal to 4:1. As a result on a wire insulating connection 1 mm thick is formed. Thick-walled and glue thermoshrinkages form a waterproofing covering from 1 to 4 mm thick on a surface. Compression coefficient in such products – 6:1.
Purchase of a thermoshrinkable tube: prices of products
Thermoshrinkable tubes are present at the assortment of any hardware store. They can be ordered on the Internet, to get in the specialized organizations which are engaged in low-current communications and power supply, in shops of electrical equipment and lighting engineering resolves issues.
The following firms are among the most popular producers:
However the cost of branded products is quite high therefore not all buyers can afford it.
Helpful advice! For isolation of connections on plaits, power cables and pipes it is better to use thermoshrinkages with coefficient of compression 6:1.
How to use a thermoshrinkable tube: installation process
Before starting thermoshrinkage mounting, it is necessary to perform a number of preparatory work.
At this stage it is required to execute the following operations:
- pick up a tube of the corresponding type and the size;
- define amount of material, necessary for work;
- prepare the tool.
Except the construction hair dryer for thermoshrinkages, it is possible to use also other tool, for example, the gas-heated soldering iron or a propane torch of the portable size. The infrared radiant burner will also be suitable for these purposes.
How to use thermoshrinkage for wires? For this purpose it is necessary:
- Clean a surface of wires from dirt and garbage.
- Cut off a fragment of a tube of the necessary length.
- Put on thermoshrinkage the site of a wire where connection is executed.
- By means of the chosen tool to heat a tube on all length.
Process of mounting of thermoshrinkage is simple therefore any person can independently perform this procedure. If for isolation the long product of large diameter is used, it is necessary to heat it in the direction from the middle to edges, previously having executed tube draft on a circle.
If mounting of thermoshrinkage is carried out on a metal base with a high rate of thermal conductivity, such surface needs to be warmed up previously. If in a zone of connection there are sharp edges, it is necessary to get rid of them, otherwise as a result of shrinkage on isolation punctures are formed. You should not stretch a product if its length is not enough to cover the site of connection as it negatively will affect dielectric properties and strength characteristics of thermoshrinkage.
Thermoshrinkable tubes reliably protect electrical connections. Thermoshrinkage as a way of isolation has many advantages therefore enjoys wide popularity.