How to choose insulating paper? What are the types?

Insulating paper is a general term for electrical insulating paper, which is used as insulating material for various electrical equipment such as cables and coils. This seemingly simple layer of paper is quite technical to choose.

First, the application environment must be determined

It is necessary to determine the environment in which the insulating paper is applied, including voltage, temperature, and humidity, and be careful to consider possible extreme conditions.

Second, clarifying the specifications is basic

The size of the insulating paper should be determined based on the design and manufacturing process of the equipment parts. If it is the first time to use it, it is recommended to get samples from the insulating material manufacturer for manufacturing and experiments. You can choose AUO Insulation Materials, which can be customized according to the drawings and the source manufacturer who takes samples for free, so as to improve efficiency and save costs.

Third, the three major parameters for judging the performance of insulating paper

In addition to the routine operations such as looking, pulling, and tearing to judge the toughness, uniformity, tensile strength, folding resistance and tear strength of the paper, there are three important parameters as follows:

Volume insulation resistance-Generally speaking, the larger the volume resistance, the greater its surface resistance.

Breakdown voltage-This parameter is an important indicator of the safety and stability of insulating paper.

Dielectric constant - it is a parameter to measure conductivity. The larger the dielectric constant of a material, the more current will pass through it under the same conditions, and the corresponding insulation performance will be worse. Therefore, it is important to maintain its dielectric constant to a certain extent.

Fourth, there are secrets in the price

Cost control is the key to optimizing the business environment, but this does not mean that in the selection of insulating materials such as insulating paper, we should blindly pursue cheapness. Some insulating papers use inferior raw materials to reduce costs, so the price will be lower than that of high-quality insulating paper. The use of this kind of paper is prone to breakage and deterioration at high temperatures.

It is worth noting that insulating paper is usually wrapped in the outermost layer of the cable to protect the cable from moisture and prevent the cable's own insulation layer from being damaged. That is to say, the performance of insulating paper not only determines whether it has high-quality insulation effect, but also directly affects the operation and service life of related equipment.

Common insulating paper products are as follows:

Cable paper

Nominal thickness (mm): 0.08, 0.13, 0.17. Applicable to power cables or other electrical insulation paper of 35KV and below.

Electrical insulation paperboard

Size: 0.1～0.6mm×1000mm Cyan/natural roll paper. 0.8, 1.0, 1.5, 2.0, 2.5, 3.0 Red/natural paperboard. Used to make laminated products and as insulating materials in motors, instruments, transformers, reactors, transformers and other equipment.

Insulating corrugated paper

Nominal width: 20-40mm. Made by machine processing cable paper.

Electrical corrugated paper

Nominal thickness: 1-2mm. Made by machine processing insulating paperboard.

Diamond-shaped glued insulating paper (dot glue paper)

Nominal thickness: 0.08mm. Used for interlayer insulation of electromagnetic wires in oil-immersed transformers, replacing the varnishing process.