The cheapest and most controversial option is matches. They are used when there is no other tool at hand, and the heat shrinkage is of very small sizes and cross-sections. For larger sizes this is not the best option.
The result is a less than neat form of compression of the tube, and the entire process can take a long time for larger items. How many matches will be needed if you need to isolate not just one connection, but several dozen?
A lighter is not always an assistant in this matter either.
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, it is not capable of creating the required temperature for high-quality compression of heat shrink.
The optimal shrinkage temperature is from 90 to 140 degrees, depending on the brand of the product.
A household hair dryer has a low flow temperature at the outlet, just a few centimeters from the nozzle; it can produce about 70C. Narrowly targeted nozzles can help with heating small diameters, but the use of non-standard ones leads to failure of the hair dryer itself. But there are thermotubes with shrinkage of 350 degrees!
As a result, you may end up with a joint that is not pressed or not fully insulated, where water can easily penetrate and moisture can be absorbed. Therefore, instead of using improvised means, try to always use a professional tool.
What is heat shrink tubing and its purpose?
This term refers to a tube made of a special heat-shrinkable material (usually thermopolymers). Such a product can change its size under the influence of a certain temperature, the source of which can be hot water, air, or an open flame.
A characteristic feature of such tubes is a high transverse compression ratio relative to the longitudinal one. That is, the tube can reduce its diameter several times (usually from 2 to 6), while its length will decrease by no more than 20% (for high-quality products 7-10%). This effect is clearly demonstrated below.
An example of changing the diameter of a heat-shrinkable tube (hereinafter HERE) under the influence of temperature
The figure shows a cambric, one part of which was subjected to heat treatment (B), the second, which was not subjected to heating, retained its original diameter (A).
Note that as the diameter decreases, the thickness of the walls of the product increases, which increases its electrical insulation characteristics.
Having dealt with the definition, let’s move on to the purpose, that is, the scope of use of heat-shrinkable materials. The main directions are as follows:
- Insulating material for electrical installation work. At the current time, it can be stated that electrical tape has almost been replaced by heat shrinkage. It is more convenient, more practical and meets the standards of GOST 19034-82.
- Thermal tubes have proven to be excellent protection against corrosion.
- Thanks to this coating, additional mechanical stability is provided for moving mechanisms; an example is the heat-shrink coating of rollers and conveyor rollers.
- Thermal tube casings are widely used in cable marking; for example, you can take any SCS.
Example of digital (A) and color (B) marking using heat shrink for wires - Application in various areas of production where it is necessary to provide protection from an aggressive environment, including the destructive effects of the atmosphere.
Main characteristics
Heat-shrinkable tubing is a special insulating element that, when heated, changes its diameter, indicated in millimeters (mm), reliably protects and insulates the base placed inside from damage.
Heat-shrinkable tubes are made from heat-polymer materials with high heat-resistant properties.
There are certain requirements that apply to heat shrink elements:
- elasticity;
- resistance to high temperatures;
- lack of flammability;
- resistance to aggressive environments;
- rapid deformation;
- tensile strength – 15 MPa and above;
- elasticity - the ability to increase by 300% of the original size.
The most popular insulator are tubes that can deform at temperatures from 55 to 120 degrees Celsius, but there are products that can withstand heating up to +300 C.
The properties of this thermal insulation allow, when heated, to completely follow the contours of the object that should be insulated.
Basically, thermal insulating elements are used for electrical insulation of contacts, wires, terminals, but in some cases this material is used to protect metal products from corrosion.
Application area:
- electricity;
- cable production;
- protection of equipment used in electrical installation work;
- installation, repair of couplings;
- marking of wiring during insulation through the use of elements of different colors;
- in nuclear energy as a supplement during installation work.
In addition, it is used to protect wires from destruction and insulate objects in all areas of production.
Kinds
Products in this group are classified according to the manufacturing method and the materials used for this. Depending on this, the following types are distinguished HERE:
- Polyolefin . They are made on the basis of chemically or radiation-crosslinked polyethylene, to which the addition of plasticizers, dyes, materials that help suppress combustion, etc. is added. Most heat shrink materials are produced using this technology. Operating temperature range from -50°C to 125°C. With special additives it can be expanded to 150°C. Good resistance to benzene and strong oxidizing agents, but with prolonged contact with fuels and lubricants the material is destroyed.
- Elastomers (base - synthetic rubber) . A distinctive feature is resistance to high temperatures (up to 175°C) and the harmful effects of fuels and lubricants. Unfortunately, the high cost of such products negatively affects demand.
- PVC (PVC) tubes made from thermoplastic polyvinyl chloride . This material has excellent insulating properties, but the small operating temperature range (from – 20°C to 80°C) and toxic emissions during fire significantly reduce its demand. It should be noted that rigid PVC is practically non-toxic, but the advent of PET technology (see below) has led to a reduction in the production of PVC materials.
- Heat-shrinkable polyester (PET) , this material has good chemical resistance and physical strength. It is ideal for the production of thin-walled and ultra-thin-walled TUT, replacing PVC materials.
- Fluoropolymer tubes. Due to complex technological processing, these products are used to solve specific problems when it is necessary to obtain unique physical and chemical properties.
Transparent PTFE Heat Shrink Tubing - Silicone based products. It is flexible and non-toxic. In addition, such products are chemically inert and have high electrical strength. Unfortunately, this material is not resistant to organic solvents, which makes it impossible to use silicone tubes for fuels and lubricants.
HERE it is also customary to classify according to the principle of installation; depending on this, the following types of heat shrinkage are distinguished:
- With an adhesive layer applied to the inside of the tube. This ensures the required level of sealing, preventing moisture from penetrating. As a rule, such tubes “shrink” threefold.
Medium-wall adhesive HERE - Without adhesive layer.
In addition, HERE they are distinguished by wall thickness, they can be:
- thin-walled;
- mid-wall;
- thick-walled.
Manufacturers also produce special types of TUT that have certain additional properties. Examples include products with increased electrical density (up to 1000 V), fluorescent additives, corrugated surfaces, etc.
Large Diameter Fluorescent Heat Shrink Tubing Set
Heat Shrink Tools
In fact, there are only five heating construction tools. Let's look at them:
- construction high-temperature hair dryer for heat-shrinkable tube;
- special butane-based burners;
- gas soldering irons;
- propane burners;
- infrared device.
The best option for heating heat-shrinkable, thin-walled elements is a construction hair dryer . Its temperature conditions can be adjusted; in addition, you can purchase special nozzles for uniform heating.
Its disadvantage is that the heating of thick-walled material will take a long time, and the quality of compression will be unsatisfactory.
Before you start heating with a hairdryer, you need to hold the heating area with your hand so that the strong air flow from the nozzle does not cause the element to move from its place.
A burner with infrared radiation does not have these disadvantages, since heating is carried out in a matter of minutes, without a strong air flow.
Important! When using infrared radiation, you should know that elements of black or dark shades absorb heat faster, so there is a high probability of burning through the thermal insulation when heated.
Gas burners are good to use because the flame has several functions. It is worth understanding that shrinkage should be done on the softest flame. How can you tell if the flame is soft? Adjust the burner so that all flames are yellow; the same indicators should be used when using a gas soldering iron.
Interesting to know! Since this thermal insulation is used everywhere, including in mechanical engineering, the question arises: how to heat the heat-shrinkable tube for a gas pipeline. There is one most important limitation: open fire in any form cannot be used for heating. It is better to use a hair dryer or an infrared emitter to insulate the gas pipeline.
A propane torch is the most suitable tool for compressing thick-walled thermal insulation elements.
The correct choice of devices for heat shrink work depends on the following nuances:
- Thermal insulator size;
- Wall thickness;
- Material of manufacture.
Before choosing one heating method or another, study the characteristics of the material you plan to use.
Watch the video - how to use heat shrink, how to heat it, etc.
HOW TO USE HEAT SHRINK TUBE [Radio AmateurTV 86]
How is heat shrink better than electrical tape?
There are two main indicators for which thermal tubes are preferable to insulating tape:
- When using a thermal insulator, you don’t have to worry that it will lose its desired properties over time;
- the electrical tape sticks to the insulated surface and leaves a dirty mark on it. As for thermal tubes, with the correct selection of shade, you can get an aesthetic appearance of any product. Removing the material is not difficult: you just need to cut the heat-shrinkable tube lengthwise;
- a very convenient material, if the contacts are very close to each other and wrapping with electrical tape is problematic - there is not enough space.
Thanks to their positive qualities, thermal tubes have become so popular and are used in many fields of activity.
Heat shrink tubing or electrical tape
Types of tubes, how to choose according to characteristics
There are several types of heat-shrinkable tubes, differing in design and nature of operation:
- Adhesive heat-shrinkable tube – has an adhesive layer on the inside. This is a very popular material for insulation, since when heated, the joints are completely sealed. Thanks to this, the connection is reliable. The shrinkage coefficient of this tube is 300%, which allows you to isolate objects whose diameter is much smaller than the tube itself. The adhesive heat-shrink tube can be cut, if it is not possible to put it on the element entirely, and then heat it up; thanks to the inner layer, the seam is hermetically sealed.
- Thick-walled thermo-shrinkable tube - made from polyolefin. This is a very affordable insulator, it is easy to use, and such a tube costs much less than an adhesive tube. This thermal insulator has a very wide range of colors and can be divided into:
- without fire suppression;
- thermotubes with combustion suppression.
The second option is used as heat shrinkage in electrical engineering production, military industry, and explosive enterprises. These heat pipes are capable of self-extinguishing if they are not exposed to constant open fire, since non-flammable substances are used in production.
- Special thermotubes are used in specialized enterprises for additional insulation. There are several subtypes of material:
- fluorescent - used in dimly lit rooms, these tubes absorb light energy during the day and begin to release it at night;
- high-voltage elements - used for insulation work, when installing high-voltage networks;
- Teflon - used in the chemical industry;
- corrugated - used for insulating tool handles and electrical appliances.
- Fabric Heat Shrink Tubing - Flame Retardant, Halogen Free, Braided Fiber. Used to prevent abrasion and mechanical damage to wires and plastic pipes. When heated, fabric insulation decreases in size by half, which allows you to insulate products of non-standard shape.
These are the most common types of heat-shrink insulation, which are used in all areas of production.
Watch the video - recommendations on heat shrinking, what to heat with, etc.
Heat Shrink Recommendations
Which products are best to use and why?
Experts advise using polyolefin tubes. Why, out of the total number of heat-shrinkable tubes, is this one preferred?
The fact is that, thanks to the manufacturing material, these tubes received the following characteristics:
- resistance to chemical influences;
- incombustibility and fire resistance;
- tensile strength;
- good shrinkage.
This is a reliable product that is produced using the latest technology and according to the requirements of the production process. They are produced in any configuration and for various types of thermal insulation.
Installation
Before installing heat-shrinkable insulation, the surface must be prepared - cleaned and degreased. The tube must be cut so that the edges are smooth and free of jagged edges.
Heating is carried out without exceeding the temperature recommended by the manufacturer. Otherwise, the handset will not sit straight. The heat-shrinkable insulation is heated from the middle, gradually moving towards the edges.
Correct shrinkage is:
- No bumps or waves;
- Perfectly smooth surface;
- No bloating.
We looked in detail at how to heat a heat-shrinkable tube at home - there are many options and everyone can find something suitable for themselves.
Properties and technical specifications
The main characteristic of HERE is the shrinkage coefficient, it can be from 200% to 600%. Accordingly, an important parameter is the diameter of the product before and after heat treatment. The technical specifications also indicate resistance to a particular operating environment. Depending on this, the product may be:
- oil resistant;
- chemically inert;
- high-voltage (insulation can withstand voltages up to 1000 V);
- petrol resistant;
- light-stabilized, not exposed to solar radiation, in particular UV;
- heat-resistant (non-flammable).
Also important characteristics include the temperature of shrinkage and operating range.
As for the shape HERE, it can be flattened, oval and round. This does not affect the installation in any way, but is made for convenient transportation. As a rule, thin-walled products are supplied in coils, and for this it is more convenient to give them a flattened and oval shape.
High temperature HERE in bays
Adhesive and thick-walled products are transported in cut form to prevent kinks.
Advantages of use and installation rules
In addition to insulating electrical cables, heat-shrinkable tubes are used when laying sewer and water supply pipes. However, their design differs from that described above. Most often, they consist of several components, the installation of which occurs in stages.
If the installation technology is followed, the TF provides the following insulation qualities:
- Mechanical strength. Due to the relatively high rigidity, breakage of the wire at the installation site is practically eliminated.
- Reliable protection against moisture. This reduces the likelihood of corrosion on the conductors, and also contributes to a lower rate of oxidation of the contacts.
- Electrical insulation.
Installation of heat shrink tubing is simple. To carry it out, you must first prepare the connecting wires. After stripping the ends of the insulating layer, the total length of the wiring is measured where it is necessary to install the TF. For stranded wires, it is best to use a complete set, which contains tubes of various thicknesses. It is selected according to the diameter of each cable. After compression, the diameter of the TF should be less than the cross-section of the rein. For example, for a core with a thickness of 2.5 mm, a coupling with a diameter of 3 mm with a coefficient of at least 2 is needed.
Each cable component must be insulated separately. Using the step-by-step instructions as an example, you can see the procedure for insulating a 3-core wire.
After completing the work, each section is checked for leaks and tight fit of the coupling to the cable.
The cost of TF directly depends on their type, size and configuration. The price of 1 set with products of various diameters will range from 600 to 1300 rubles. This is the cost of a professional set made in Europe. Piece sales are rare. On average 1 m.p. will cost from 30 (2.5 mm) to 90 (35 mm) rubles.
When choosing, you should pay attention to the geometric dimensions of the product, wall thickness and color marking. The shrinkage factor should also be taken into account. Good insulation of two contacts is the key to long-term operation of electrical wiring, plus high safety
Therefore, insulating tape is one of those materials that an electrician always has on hand. But it is gradually losing its position to heat-shrinkable tubes, which are superior to the former in many technical characteristics. So, let's figure out what heat shrink for wires is (dimensions, what materials it is made of, and how it is installed)
Good insulation of two contacts is the key to long-term operation of electrical wiring, plus high safety. Therefore, insulating tape is one of those materials that an electrician always has on hand. But it is gradually losing its position to heat-shrinkable tubes, which are superior to the former in many technical characteristics. So, let's figure out what heat shrink for wires is (dimensions, what materials it is made of, and how it is installed).
Let's start with the fact that the main property of heat shrink tube (HEET) is to shrink in size under the influence of high temperatures. That is, you put it on the contact of two wires and expose it to temperature, the tube immediately decreases in size and fits tightly around the electrical contact. What can cause fever? The best option is a special hair dryer, which is used specifically for this operation. If there is none, then you can use a lit candle, lighter, matches, and so on. That is, the flame of an open fire is suitable for this. But keep in mind the fact that contact with fire is contraindicated, and overheating the tube will not lead to anything good. The material will become covered with bubbles, become rigid, and will quickly crack.
Marking of heat shrink tubes
In most cases, the markings indicate the main parameters HERE, namely: diameters before and after shrinkage.
Example of heat shrink tube designation
As a rule, these parameters are indicated through a fraction, for example: “4.80/2.40 mm”. It happens that diameters are indicated in inches, most of them on products manufactured in the USA and Europe. But you shouldn’t trust this too much; counterfeit products may also have similar markings.
Some manufacturers indicate the original diameter and shrinkage ratio on the tubes, for example: “20 mm 3:1”. https://www.youtube.com/watch?v=1DTd9rVJN9Y
How to use heat shrink for wires
It is necessary to select the right tube for heat shrinking and prepare the appropriate tool.
First of all, it is necessary to analyze the features of the cable to which this switching method will be applied. Installation of heat shrinkage is carried out in a matter of minutes, without requiring special skills or tools.
Preparatory stage
The preparation process involves selecting the right material and processing it for use. Before placing the heat shrink tube over the insulation, you need to make a careful cut. The segment should be 10% larger than the area that needs to be insulated.
DIY installation of heat shrink tube
During installation, a piece of tube is placed on one side of the wire, after which a connection is made to the other. Then the product is moved to the desired place and heated evenly with a hairdryer or open fire (using a lighter) on all sides.
It is important not to overdo it, otherwise the heat shrink from overheating may become deformed and slip out of place. After processing, it is necessary for the insulation to cool down, after which it can be packed into distribution boxes.
An important condition when working with heat-shrinkable material is compliance with safety precautions. All manipulations must be performed with the electricity turned off.
Size range of heat shrink tubes
The product range (in our case, size range) depends on manufacturers and suppliers. You can get complete information on this issue on the official websites of manufacturers or their dealers. As an example, we provide information on the size range HERE®.
Table: available sizes from the manufacturer HERE®
Where can I buy
Now you can find several hundred stores that offer to buy it. However, whether the heat shrink tube will be of high quality is a big question. Quite often on our territory you can find Chinese goods, buying which every person will have many questions about their quality. For example, it will be difficult to heat it or it will not fit normally to the conductor.
When buying cheap Chinese copies, you risk getting a lot of problems. Therefore, it is better to purchase them from trusted stores that provide real guarantees. One of these now is https://thermolink.ru, here you will discover a large assortment, low prices and high quality. The store occupies a leading position in this market segment and offers its customers only favorable conditions.
Selecting Heat Shrink Tube
First of all, you need to decide on the operating conditions, then select HERE with the appropriate characteristics. For example, if contact with fuels and lubricants is possible, then the product must be oil and gasoline resistant. If it is necessary to ensure reliable insulation of the wires of a high-voltage cable, a tube is selected with protection at the connection point up to 1000 V.
Next comes an important point - selection of diameter HERE. In this case, the “-10+20” principle should be used. It is as follows: the minimum shrinkage should be no less than 10% of the original diameter and no more than 20% of the specified shrinkage parameter. A clear example of how this principle works is presented below.
An example of how to choose optimal shrinkage
When choosing the length, it should be taken into account that HERE gives longitudinal shrinkage. In low-quality products from the Land of the Rising Sun, it can be up to 20%. In branded kits, as a rule, longitudinal compression does not exceed 5-7%.
Areas of application
What is heat shrink tubing for? Heat shrinking is necessary for high-quality insulation of junctions of 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 inside of the heat shrink, allowing it to be attached to metal or wood.
The wide color range allows heat shrink tubing to be used not only for protection or insulation, but also as a mark 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.
The ground pin is usually indicated by a yellow-green color.
Ease of use and durability make heat shrink tubing an excellent and reliable alternative to outdated duct tape.
How to use?
It is advisable to have specialized equipment for this process - a hot air gun or a heat gun. You can set the required shrinkage temperature on them, which greatly simplifies the process. If it is not possible to use special equipment, you can heat the tube with an open flame (a lighter or a match) or place it in boiling water.
Let us describe in detail the algorithm of actions:
- Thick or large cross-sections are recommended to be heated before the process to half the nominal temperature required for shrinkage. The same applies to wide elastic bands. Thin-walled products or small-diameter tubes do not need to be heated in advance.
- Carefully cut off the required length HERE. This can be done with ordinary scissors. Make sure there are no tears or burrs, as tearing may occur during the shrinking process.
- Next, the tube needs to be slightly stretched, and then pulled onto the selected location. You also need to put it on HERE carefully so as not to damage the integrity of the surface.
- Heating is carried out in accordance with the specified temperature. Exceeding it can lead to surface deformation. The hot air flow must be directed from one edge to the other or from the center to the edges.
- Once heating is complete, allow the tube to cool. After this, the procedure is considered completed.
As you can see, using HERE is quite simple, the main thing is to produce uniform heating and not exceed the permissible temperature. If during installation the heat shrink tube bursts or becomes deformed, it must be removed and replaced.
Open flame shrinkage - pros and cons
An open flame is a lighter, candle, match or other source of fire. If we consider an open flame for heating, then it is worth knowing some nuances:
- Thermal insulation may undergo severe deformation when exposed to strong heating;
- If the flame is not removed in time, the heat shrink may simply burn out;
- White, colored heat-shrinkable element may smoke when heated.
The main problem with open fire shrinkage is that the source of heat is always at the bottom, and in order to heat the insulator evenly, the connection must be constantly rotated. This is the only way it will heat up evenly.
In addition, you must strictly maintain the distance from the structure to the open fire. It should not be less than 3-4 cm; it is at this distance from the flame that the temperature is highest. Do not use gas burners or turbo lighters for heat shrink tube for heating - it will immediately become unusable.
Advantages and disadvantages
The advantages of HERE are that it is not subject to mechanical stress due to its compact enclosure of the insulated parts. This is also a simple and effective way to protect yourself.
When exposed to high temperatures, heat shrink becomes more rigid and durable. In addition, this method gives good results for many years. This method is widely used for other purposes.
The disadvantages of heat shrinkage are the inability to reuse, and the price of this product is quite high compared to electrical tape.
Terms of use
The first step is to select the right size. So, if the goal is to isolate the contacts, you need to cut off a piece of the tube that should cover this area. It should be taken into account that when heated, the heat-shrinkable tube will shrink. Often this longitudinal shrinkage occurs by 10%. It is better to cut such a piece with a margin.
It is necessary to pay attention to ensure that the edges of the segment are smooth, without damage to the surface, as this can lead to rapid disintegration of the material.
It is advisable to choose the diameter of the tube so that the tube can easily fit onto the damaged area, but does not significantly exceed it. If the diameter is too large, the compression will not be tight enough.
Next, a tube is pulled onto the wire, then you need to securely connect the contacts and put it on top of it HERE. The next stage is warming up. During this process, the edges are heated from one to the other so that large longitudinal shrinkage does not occur. You can also start heating the tube from the middle to avoid the formation of an internal bubble.
Wires with heat shrink tubes
For this procedure, you can use matches, a lighter, a hair dryer, or any available means. The main thing is not to overheat the tube; the exposure temperature should be between 100-130 degrees.
What to do if a person is electrocuted? Everyone should know this, everyone should read it!
In addition, you should avoid wrinkles that can form when heated. This process is done slowly, carefully and evenly so that the tube does not rupture. If the procedure is carried out quickly, exposure to high temperatures can damage the heat shrink.
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.
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.
