A Guide to Electrical Engineering Materials for Everyone. Part 11 / Sudo Null IT News

Electrical tape is a consumable material, a type of adhesive tape designed to insulate electrical wires, preventing short circuits and direct contact with exposed areas of the electrical circuit. In addition, it is used to hermetically isolate objects and parts from direct exposure to environmental factors, which include sunlight, water and other liquids. Production has made great progress and insulating clamps are constantly improving their characteristics, which are useful to know not only for electricians, but also for ordinary people.

Electrical tape

When it comes to electrical tape, the first thought that comes to mind is blue PVC electrical tape from the times of the USSR.
It is blue electrical tape that is the basis for jokes and comments that carry no value in some communities. But electrical tapes are produced not only on the basis of PVC film; there are many other types of electrical tapes and below is a list of the most popular electrical tapes. The type of electrical tape is selected based on the tasks, operating conditions, and operating requirements. UPD: This is version 1.0, in version 1.4 this section was significantly expanded. Download links are in part 12.

Materials used for the production of electrical tape

Modern electrical insulating tapes are produced according to Russian GOST standards. To create, all kinds of materials are used in combined and pure form. Most often in modern conditions you can find tape that is made of polyvinyl chloride (that is, PVC), as well as cotton material (that is, cotton).

Both of these types of electrical tape are considered the most popular and are used for different fields of activity. Electrical insulating tapes made from woven natural or non-woven materials are incredibly popular.

The fact is that it is they that help ensure excellent conductivity of electricity, and they are often used for bundles. There are other types of insulating tape, and each of them has its own advantages and disadvantages.

Rubberized fabric tape

An artifact of the Soviet era is still produced and sold - fabric insulating tape (GOST 2162-97) - cotton fabric impregnated with rubber. One of the advantages is that when heated it does not melt, but chars. This is where its advantages end. Despite the impregnation, it is still partially hygroscopic and dries out over time, losing its adhesiveness. Enjoys special love among oldfags.

Fabric rubberized electrical tape of modern production.

Where and why is adhesive film used?

Adhesive tape is used:

when carrying out electrical work in any room;
during auto repair work for laying and insulating wiring;
when connecting and sealing pipes that are wrapped with electrical tape in order to prevent the penetration of groundwater and moisture, which provokes the development of fungus and corrosion;
when insulating glass packages, window tape is used;
when packaging goods with manual or machine sealing of boxes;
when repairing tourist boats or air mattresses as a temporary patch;
When installing the air conditioning system, PVC ventilation tape is used.

The thickness of such tape varies: from 0.11 to 0.20 mm. This expands the scope of its application. For example, to ensure that your home is always warm, you can seal the seams and slopes on the frame with PVC tape for windows.

Imagine what human life would be like without the presence of such building material as a banal roll of adhesive film.

Self-vulcanizing rubber tapes

They are a thick (0.5-1 mm) rubber band with a protective layer. When insulating the connection, the protective tape is removed, and the tape is tightly wound and overlapped. When exposed to air, the overlaps self-weld, forming a monolithic layer. Such a winding cannot then be unwound, only cut.

A roll of self-adhesive (self-vulcanizing) electrical tape. The protective thin layer is removed during winding, and the tape itself is stretched, tightly wrapping around the joint.

PVC insulating tape. Top 3 - The most famous and best brands in terms of quality and reliability.

EKF is an international company, one of the world's largest manufacturers of electrical products, the quality and reliability of which is recognized throughout the world.

Over many years of its own production practice, it has accumulated a wealth of successful experience, thanks to which it is possible to combine the highest possible technical characteristics of products, attractive design, ease of installation and maintenance.

Today, the company’s product range is huge and includes thousands of items: circuit breakers, measuring instruments, sockets, controllers, electricity meters, switches, extension cords, surge protectors, RCDs, sockets, bells, connectors and much more.

All news is available in our special section below.

Expanded color range of SafeFlex electrical tape – more installation options

The SafeFlex line of professional PVC electrical tape is replenished with brown tape. The product is produced in rolls 20 m long, the film width is 19 mm. The new product can be used for insulating and marking conductors, in particular, for marking phase...

PVC insulating tape EKF SafeFlex

Polyimide tape

Also known as “thermal tape”, “Kapton tape”. (Kapton, like Teflon, is a registered trademark that has become a household name in some places.) Yellow transparent heat-resistant tape, often seen in phones and laptops - it secures cables and wires.

A roll of self-adhesive heat-resistant insulating tape.
Heat-resistant (does not melt with a soldering iron), does not stretch, and does not tan in the cold like PVC. Rarely encountered outside electronic technology. It is used when repairing equipment; when soldering with a hairdryer, such tape can be used to seal elements that cannot be soldered, so as not to accidentally blow them off.

Scope of application of insulating tape

Electrical tape has found wide application in various industries - both industrial and household. Previously, it was even used in sports: they wrapped hockey sticks to absorb shock and extend the life of sports equipment.

Professional area of using electrical tape:

Electrical insulation of splices of cables and wires of various voltages.
Protective cover for high-voltage and low-voltage busbars.
Repair and insulation of high-voltage cables.
Harnessing cables and wires.
Color identification of supply wires, electrical phases, pipeline systems, fencing of various zones with varying degrees of danger.

The standard thickness of the insulating tape is 13-20 mm, and the larger it is, the better the electrical insulation properties of the material. The 3M ™ company produces tapes of increased thickness (22 mm or more) used for insulating high-voltage cables.

PVC electrical tape

The most common type of electrical tape. When we say “electrical tape,” blue PVC electrical tape immediately comes to mind. Plasticized PVC tape with an adhesive layer. It is not afraid of moisture; a connection insulated with such tape is not afraid of bending. The quality of electrical tapes varies from “does not stick” for poorly stored old domestic ones to “a pleasure to work with” for branded products from 3M or Tesa.

Different colors of electrical tape.

Buns

The only electrical tape with a wide palette of colors - black, green, red, brown, gray... for every color and taste, and there is even pink, purple and orange on order.
There is also a striped yellow-green one - everything for color marking of conductors according to the PUE. And only a clinical idiot would wrap all connections with yellow-green electrical tape for PE conductors.

It stretches well - it is possible to insulate complex joints without wrinkles or bubbles.

Flaws

Afraid of heat.
When overheated, it drains, although it follows the insulation of the wires. With prolonged low heating (80 - 100°C) it loses elasticity and crumbles.

Afraid of the sun.

In the sun it loses color and elasticity.

Crawling.

This is a drawback of all electrical tapes with a non-drying sticky layer. If the electrical tape is wound with great force, it gradually “creeps” along the adhesive layer.

Deformed rolls of electrical tape. The tape was wound onto the roll with force and the tape “crept” along the adhesive layer.

It gets dull in the cold.

The disadvantage inherent in PVC is that if you try to wrap a connection at an outside temperature of -5°C, you may encounter the fact that the electrical tape does not stick, and in the severe Ural frosts of -35°C, the electrical tape may fall out of your hand and break. Some manufacturers produce special frost-resistant electrical tapes that can be used at low temperatures.

Purpose and main characteristics

Typically, electrical tape takes the form of a film, which is cut into separate strips of different lengths. The material most often used is polyvinyl chloride. The inside of the electrical tape is coated with a special adhesive composition made of acrylic or rubber.

The materials used, and not only PVC, must be heat-resistant, resistant to aggressive environmental factors, and not sensitive to fire.

The purpose of electrical tape is extensive - it is used in a wide range of engineering and technical works and serves as an effective way to protect various objects.

But the main scope of application is, of course, a complex of electrical and installation work, when it is necessary to carry out:

strong connection of wires and cables;
insulate live and exposed sections of the wire.

Additionally, this material can be used for marking, fastening, and combining several wires into one set.

There is another use option - increasing the strength of cables, as well as protecting their sheaths from mechanical stress. This tape can also be used for insulating pipeline connections.

The main characteristics of electrical tape that need to be taken into account when choosing products are as follows:

degree of adhesion to the surface;
electrical strength;
elasticity;
resistance to moisture;
high degree of safety in case of fire;
absence of toxic components in the natural state and when heated.

Stationery adhesive tape "scotch tape"

Scotch is a trademark, but like a thermos, copier, scuba and other brands, it has become a household name for transparent adhesive tape.
Although such adhesive tape is not used in electrical engineering, it is worth mentioning. It is most often made from BOPP - Biaxially Oriented Polypropylene. Scotch tape is transparent, quite durable and a good dielectric. Unfortunately, such adhesive tape is prone to a “zipper effect” and the presence of cuts allows the tape to tear with minimal force.

One layer of adhesive tape can withstand a voltage of about 1000V AC, so if you need to insulate a connection, and there is nothing else at hand, then this can be done with adhesive tape, although the quality and reliability of such insulation will be low.

Advantages of the material

Electrical insulating tape has many advantages, including:
Excellent stickiness.
High temperature resistance.
High voltage current resistance.
High level of strength.
Non-toxic material.
High elasticity.
Excellent resistance to moisture.
Availability.
Fire protection.

Thanks to the excellent properties of the material, insulating tape has become ideal for domestic and professional use. Most people wonder whether it is possible to use the most ordinary packaging adhesive tape instead of electrical insulating tape when they want to save money and time, but here you should understand the fact that such material is not intended for work with electrical wiring and is only suitable for temporary use .

PVC pipe

It was widely used in the USSR for insulating connections of wires to terminals, connecting wires to each other, wherever heat-shrinkable materials are now used.

The places where the wire is soldered to the connector are covered with cambrics.

Still sold and used today. It has low elasticity, so measures must be taken to prevent the tube from jumping off and sliding along the wire.

In some cases, it is quite possible to use various PVC hoses as an insulating tube, incl. for compressors, aquariums, etc. All the advantages and disadvantages of polyvinyl chloride remain the same and are described in the section above on PVC.

Scope of direct application

Electrical tape is widely used due to its beneficial properties. Most often it is used in:

For the purposes of protecting electrical installations from short circuit currents both on a domestic and industrial scale;
During the marking process, when it is necessary to assemble wires into bundles;
For laying electrical wiring during car repairs;
To protect pipelines from aggressive humid environments, corrosion, and fungal (moss) growth;
Sealing of joints;
Connection of asbestos cords;
Protection of cable sheaths, their strengthening.

Fluoroplastic tube

Used as heat-resistant insulation, especially when paired with MGTF wire. Just like fluoroplastic, it does not like long-term mechanical stress, but it maintains a fairly high temperature. Slippery and not elastic.

PTFE insulating tube. In the center is a piece of pneumatic fluoroplastic tube.

In the plastic feeding mechanisms of 3D printers, a fluoroplastic tube for pneumatic systems is used as a thermal barrier (outer diameter 4 mm, inner diameter 2 mm). When feeding plastic filament through such a tube into the extruder, the slipperiness of the fluoroplastic plays an important role.

Wire insulation methods

Heat shrink tube (sleeve)

Externally, the tubes resemble ordinary wire insulation made of plastic. The principle of using the tube is simple: it is placed on the cable before the wires are joined, after which the edges of the coupling are located on the cable insulation. Then, using an industrial hair dryer or a gas burner, the temperature of the tube is increased, as a result of which its diameter narrows and the surface is reliably compressed at the junction of the wires.

The advantages of using couplings are:

high mechanical strength;
providing protection against moisture penetration;
reliable electrical insulation.

Heat-shrinkable sleeves provide reliable insulation of wires in any operating conditions

Expensive brand duct tape

Most cheap brands of electrical tape are only suitable for wrapping around a club or shovel handle, but not for connecting live wires. To ensure reliable insulation, you should purchase more expensive brands of electrical tape.

Working with any type of electrical tape is quite simple and does not require any specific skills or knowledge. It is recommended to start winding with the factory insulation of the wires at a slight angle so that the layers of insulating tape gradually move towards the twisting point. Winding continues until it goes beyond the boundaries of the twist and an empty tube is formed, the length of which corresponds to the width of the electrical tape.

Next, this section of twisted tape is bent and laid along the wire connection in the opposite direction. Winding the electrical tape continues at the same angle, only in the direction of the factory cable insulation. Excess material is cut off.

Silicone insulating coating

Silicone is considered an excellent insulator with high strength and low electrical conductivity. The material is able to reliably protect the inner surface of the wire from leaks and current breakdowns.

The temperature range of application of silicone insulation is quite wide; it is resistant to sudden temperature fluctuations. In terms of mechanical strength parameters, the material is close to liquid insulators. Also, the insulating coating made of silicone is non-flammable and lasts several times longer than ordinary electrical tape.

Using different terminals

The use of a PPE connecting type clamp ensures reliable insulation of twisted wires

This method of wire insulation involves the use of various types of terminal blocks with a dielectric housing, for example:

Vago universal self-clamping terminals;
screw clamps ZVI;
PPE insulating clamps-connectors.

When connecting cables in a distribution box using terminal blocks, no additional insulation is required, since the devices themselves are already sufficiently insulated.

The terminals have several designs. They are available in the form of blocks or caps that securely clamp the connected wires. But at the same time, a lot depends on the current load - at high values it is better to use soldering of wires, and put an insulating sleeve on top of it.

Temporary insulation with tape

According to the rules, adhesive tape is not a certified insulating agent, therefore its use to protect twisted wires is prohibited. But there are times when there is no insulating tape at hand, and the insulation of the wires needs to be done very urgently. In this case, you can use tape, but only as a temporary solution.

The problem is that electrical tape is a colored PVC or cotton film with an adhesive surface on one side. Scotch tape is a plastic film with an adhesive base. In terms of dielectric properties, PVC and polyethylene are almost the same. There is a significant difference in the thickness of the material - electrical tape is several times thicker than adhesive tape, so for high-quality insulation of adhesive tape you will need to wind much more.

As temporary measures, just as incorrect as using tape, you can use adhesive plaster, fabric, cardboard or thick paper. Also, for short-term insulation of twisted wires, dense winding with synthetic threads or rubber tape is suitable. When using such isolation methods, you must understand that the risk in such cases is not always justified and all responsibility will rest only with you.

Reinforced tubes

There are several types, depending on the reinforcement material.
(More details can be found in GOST 17675-87). A tube made of cotton stocking impregnated with varnish is called “linoxin tube” (type 110 according to GOST 17675-87), “TLV insulating tube”, “varnish insulating tube”, and has a characteristic yellow color with a visible weaving texture. Used to insulate joints between windings of electrical machines with multi-core wires.

Where there is constant heating - kettles, irons, fan heaters, thermopots, etc., a more heat-resistant option is used - “glass-reinforced insulating tube”. It is a silicone tube covered on the outside with a fiberglass stocking, or the stocking itself is impregnated with silicone. Silicone itself is heat resistant and sufficient for insulation, but fiberglass adds strength and prevents sticking. However, silicone tubes without reinforcement are sometimes found as insulating tubes.

Fiberglass-silicone heat-resistant insulating tubes. The fiberglass reinforcing layer can be either inside the tube or outside.

It is worth noting that when using such tubes, it is necessary to take into account their fixation in place; if the placement is unsuccessful, such a tube can “slide” along the wire and expose the connection.

A Question of Choice

Before purchasing a tool, it is always wise to check its specifications and other features. You should take into account the wide range of types of insulating tapes.

In this case, we start from width, length, material, grade and adhesion. And most importantly, we define our goals.

Heat-shrink tubing

It is widely used for insulating connections and has almost completely replaced PVC cambric from its position, as it is convenient to use.
It is a polymer (The specific type of polymer depends on the manufacturer; unfortunately, it is impossible to clearly indicate that this is only polyethylene, for example.) tube with shape memory - the tube after manufacturing stretches in the cold (In fact, the temperature conditions during manufacturing are somewhat more complicated, but for convenience we will assume that in a cold state) state, which creates internal stress. When heated to a softening temperature (but not melting), the polymer tends to restore its shape and the tube “shrinks,” decreasing in diameter quite significantly. The heat shrink tubing fits tightly around the connections, ensuring that the tubing will not slip or move. Available in a variety of colors, diameters, types.

Various lengths of heat shrink tubing.

Working with heat shrink is simple - cut, put on, heat.

Soldered joint, slide on a heat-shrinkable tube of suitable diameter and heat it. After shrinking, the tube is securely fixed.

To ensure a tight connection, heat-shrinkable tubes with an adhesive layer are produced - they are coated on the inside with a layer of glue, which, when heated and settled, firmly glues the tube to the surface of the wire. Such a connection may be needed, for example, when extending the wire of a submersible pump.

Sometimes the device body consists of only heat shrink.

If you have the skill, it’s quite possible to stretch heat shrink an additional millimeter in diameter when you don’t have a suitable one at hand, and the one you have doesn’t fit, just a little bit.

If you heat the heat-shrink tube strongly and “pinch” the end, it will stick together, thus sealing the ends of the cables from moisture.

A link to the full pdf version of the manual was planned in this place, and the part was intended as the final one. But thanks to your comments, a large list of improvements has been formed. Therefore, I’m taking a break to finalize the guide, and the last, 12th part will be devoted to improvements + a bonus chapter. Write in the comments what else would you like to know?

Links to parts of the manual:

: Conductors: Silver, Copper, Aluminum. : Conductors: Iron, Gold, Nickel, Tungsten, Mercury. : Conductors: Carbon, nichrome, heat-stable alloys, solders, transparent conductors. : Inorganic dielectrics: Porcelain, glass, mica, ceramics, asbestos, SF6 gas and water. : Organic semi-synthetic dielectrics: Paper, lye, paraffin, oil and wood. : Synthetic dielectrics based on phenol-formaldehyde resins: carbolite (bakelite), getinax, textolite. : Dielectrics: Fiberglass (FR-4), varnished fabric, rubber and ebonite. : Plastics: polyethylene, polypropylene and polystyrene. : Plastics: polytetrafluoroethylene, polyvinyl chloride, polyethylene terephthalate and silicones. : Plastics: polyamides, polyimides, polymethyl methacrylate and polycarbonate. History of the use of plastics. : Insulating tapes and tubes. : Final

How to choose the right insulating tape

To know which insulating tape to choose so that it is suitable for your purposes, it is worth studying its varieties and features. When choosing a tape, you should take into account the following parameters: thickness, width, adhesion, base material, grade. Moreover, you should clearly understand for what purpose you plan to use the insulating tape.

For example, in order to insulate the wiring, you will need to take into account the maximum possible voltage and room temperature in winter and summer. We also note the fact that any type of insulating tape will ensure reliable fastening and is suitable for domestic needs.

4.1. How to choose?

Stores sell tape in rolls with a diameter of 85 mm, a width of 11–20 mm and a thickness of more than 0.11 mm.
When purchasing, do not forget about pragmatism! To insulate thin wires, a narrow 11 mm tape will be sufficient, but for pipes you will need a wider one, at least 15-19 mm. The length of the tape determines how long it will last. For home use, 10 m of tape is enough, but for daily work you should take more, for example, 20 m. Also pay attention to the color. You can mark the wires with a tape of the color you need or mask the finished section. Now the variety is much greater than before, because previously only blue PVC electrical tape was sold. Remember that a good tape is smooth, has a lot of stretch and doesn't pull away from the sleeve. There should also be no unpleasant odor.

2.2. Production now.

Modern PVC electrical tape is made from plasticized polyvinyl chloride film with a layer of glue applied to it. There are two types of glue: rubber helps the tape improve its resistance to deformation and solvents and stickiness, and acrylic, although difficult to stick at first, increases the strength of the tape connection so that after a while it becomes almost impossible to break. In addition, the sun's rays cause much less damage to acrylic glue. The tape sleeve can be made of plastic or cardboard. The second is much more popular due to the fact that PVC tape becomes stickier due to two layers of glue with a primer between them. The best electrical tape is considered to be the highest grade tape with rubber adhesive: its elasticity, stickiness and safety do their job.

Purpose

Due to its versatility, this material is used in various areas of human activity. It is applicable both outdoors and indoors. In stores you can find ribbons of different colors, but the main thing is that they do not have any unpleasant odors - this indicates low quality.

You might be interested in what is resistivity

PVC tape is not recommended for insulating polymers or silicone surfaces that contain fluorine. If the surface to be treated has defects, pores or other damage, it must first be prepared by applying a primer material. PVC tape is applied only to a dry and clean surface.

Key function is insulating

Areas of use:

work with electrical engineering. Electrical cables are insulated with tape, wires are connected, and bundles are marked;
household work. PVC tape is useful if you need to repair various things, from tools to other household items;
car repair. For example, if necessary, insulate wires and other places;
package. Thanks to the adhesive coating, this tape makes it easy to pack small boxes. Packaging work is increasingly being automated;
boat repair. To do this, use a special reinforced tape;
pipeline protection. Pipes laid in the ground are constantly affected by the negative influences of the soil, so pipelines require reliable protection. PVC insulation helps protect the outside of pipes from rust. But here it is important to use it correctly, namely, wind it in a spiral to avoid distortions. The tape, resistant to moisture, waterproofs the highways.

This is not the entire list of areas where electrical tape is used. In addition to repair work, it is also widespread in creative activities.

It is also used in design

Storage Features

When storing PVC insulating tape in a warehouse, the temperature regime must be maintained from +50C to +350C, and the humidity level should not exceed 80%. Also, all products should be kept at a distance of at least 1 meter from heating devices. Storage of acids, solvents, chemicals or other aggressive media is not allowed near the storage area of electrical tape. Similar rules apply to many types of electrical insulating materials.

4.2. How to use and store?

When insulating electrical wiring, it is best to wind 2-3 layers. PVC electrical tape does not adhere well to wet, dusty and slippery surfaces. Before gluing, clean the surface and, preferably, wipe it with a 50% isopropyl alcohol solution or sand it. Solvents, flammable and simply aggressive substances (including silicone and polymer surfaces) can damage the tape. PVC electrical tape has a shelf life of 3 years, but if properly stored it can also be used effectively after 10 years. It should be kept in a room with humidity less than 80% and a temperature of 5-40°C away from batteries. If you constantly use electrical tape at work, it is recommended to buy several rolls at once. Nowadays it is easy to purchase both domestic and imported products of different parameters (length, width, color). Even if you don’t use it often, always keep at least one skein at home in case it comes in handy.