Online inspection of paint film continuity

At present, almost all winding wire insulating paints in the world are solvent paints, which not only use organic solvents needlessly, but also seriously pollute the environment during manufacture and use, causing harm to organisms (human beings, animals and plants). For a long time, people have devoted themselves to the efforts to eliminate this kind of harm, especially in recent years, the proposal of ISO14000 will greatly promote this kind of efforts. The following is a general summary of the experimental research and trial production in this area. As an industrial promotion, it will take some time. It is expected that in the next five to ten years, certain varieties may be introduced to the market.

7 step of manufacturing of magnet wire: Material preparation, Drawing, Wash with water, Annealing, Impregnation, dry, Take-up and Packing and storage

The purpose of collecting and arranging the wire is to continuously, tightly and evenly wind the enameled wire onto the spool. The wire take-up mechanism is required to drive smoothly, with low noise, proper tension and regular wire arrangement. In the quality problems of enameled wire, the proportion of returns due to poor wire collection and arranging is very large, which is mainly manifested in the large wire tension, the wire diameter is thinned or the wire reel burst; the wire tension is small, and the wire reel is broken. Loose lines cause chaotic lines, and uneven lines cause chaotic lines. Although most of these problems are caused by improper operation, it is necessary to take necessary measures in the process to bring convenience to the operators.

Enameled wire is a kind of cable. The specifications of the enameled wire are expressed in terms of the diameter of the bare copper wire (in mm). The measurement of the enameled wire specification is actually the measurement of the diameter of the bare copper wire. It is generally used for micrometer measurement. The accuracy of the micrometer can reach 0.01mm. There are direct measurement methods and indirect measurement methods for the measurement of enameled wire specifications (wire diameter).

The raw materials for winding wire mainly include copper, aluminum conductor, insulating paint, insulating paper, polyester mesh belt, polyester film, corona-resistant film, etc.

Domestic materials can basically meet the requirements of use. The imported materials selected according to product characteristics include aramid paper, Minschke insulating paper, Weidmann heat-resistant paper, DuPont 410 paper, DuPont corona-resistant film, etc. to meet the needs of customers. Different high temperature resistance, high mechanical strength, corona resistance and other requirements.

High-voltage motors need to use diimide, monoimide, single-thin double-wire and other wire-wrapped flat wires of various specifications according to the voltage level. The straight part is 25 cm, and the maximum coil straight part is 1.2 meters. The winding can be single flat winding, single vertical winding, double flat transposition winding, or double flat transposition vertical winding, which is determined according to specific requirements. Round enameled wire coils can also be wound using the universal adjustment in the disc. The winding machine has a built-in speed regulating motor and a turbo reducer, which drives the winding machine to achieve 0-120 rpm reversible and brakeable rotation, and can count forward and reverse, generally 1600KW can be wound All kinds of motor coils within the range are also equipped with a set of simple tensioners, which can control the tightness of the winding coils. General repair manufacturers can choose the above products. If they encounter special large-scale specifications, they can choose special type windings. equipment.

LP Industry is a professional magnet wire manufacturer in China, mainly poduce the round aluminum winding wire and flat aluminum enameled wire. Magnet Wires Manufacturing Process includes extruding wire in suitable size, cleaning wire, wire enamel insulating varnish and winding on spool.

Although the quality of enameled wire depends to a large extent on the quality of raw materials such as paint and wires and the objective conditions of machinery and equipment, if the operation does not take a series of problems such as baking, annealing, speed, etc. seriously and understand their interrelationships , Without mastering the operating technology, not doing the touring work and parking finishing work seriously, and not doing well in the process and hygiene, even if the objective conditions are good, it will not be able to produce high-quality enameled wire. Therefore, the decisive factor for a good enameled wire is people, and people’s sense of responsibility for work.

In terms of enameled production equipment, the wide application of low energy consumption, low emission and high-speed wire drawing enameling machines has made our country in the forefront of the world in this field.

The temperature distribution of the oven has a great relationship with the baking of the enameled wire. The distribution of oven temperature has two requirements: longitudinal temperature and transverse temperature. The longitudinal temperature requirements are curved, that is, from low to high, and then from high to low. The lateral temperature requires a linear shape. The uniformity of the lateral temperature depends on factors such as equipment heating, heat preservation, and hot air convection.

Enameling machine is an important equipment for the production of enameled wires in the magnet wire industry. Its function is to evenly wrap the processed copper wire (or aluminum wire) with a layer of insulating polyester paint. The enameled paint used in the production process of enameled wire contains a large amount of diluents and organic solvents, and the main components are benzene, xylene and cresol, which volatilize when the paint film is heated and cured, causing environmental pollution and energy waste. There are more and more manufacturers of enameled wires, and the energy saving and environmental protection of enameled machines have also become a problem that cannot be ignored.

1. Aluminum magnet wires are winding on the wooden wheels or plastic wheels.
2. The wheels are packed in poly bag separately, and put into the plastic-envelop machine, then the wheels are water and moisture proofed.
3. The Enameled wheels in plastic-envelop, then shall put into carbon box, and pile up well on wooden pallet, then covered by wooden case, so as to avoid any crash and impact from outside.
4. Some wooden wheels are packed as below on request, so as to avoid the different wire layers in split level.

Painting is the process of coating the enameled wire paint on the metal conductor to form a uniform paint layer with a certain thickness. The number of painting passes is affected by the solid content, viscosity, surface tension, contact angle, drying speed, painting method, and thickness of the paint layer. The general enameled wire paint needs to be coated and baked many times to make the solvent evaporate fully, the lacquer resin reacts completely, and a good paint film is formed.

In the course of the Company’s operation, certified management systems are applied such as the quality management standard ISO 9001:2008 and the environmental management standard ISO 14001:2004, staff healthy and safety management standard OHSAS 18001:2007, The Company issues certificates for the compliance of all aluminium products with the European Union standard.

Paint film continuity testing has used some offline testing methods, such as voltage mercury method, Japanese salt water method, low-pressure electrolyte method, etc., which are not suitable for online testing of enameled wire in the production process.

The key to pay off is to control the tension. When the tension is high, it will not only draw the conductor thin, make the surface of the wire lose its brightness, but also affect many properties of the enameled wire. From the appearance point of view, the enameled wire that is drawn thinner has poor gloss; from the performance point of view, the elongation, resilience, flexibility, and thermal shock of the enameled wire are all affected. If the pay-off tension is too small, the line will easily jump and cause the line to be merged and the line to touch the furnace mouth. When paying off, the most fear is that the half-turn tension is high and the half-turn tension is small. This will not only cause the wires to loosen, break, and be thinned one by one, but also cause large jumps of the wires in the oven, resulting in failures of merging and touching the wires. Pay-off tension should be even and appropriate.

¡ñConductor resistance. Measured with a conductor resistance tester, and then changed to the value at 20¡ãC for comparison.
¡ñ Dielectric breakdown voltage. Twist two enameled wires, apply voltage between their conductors, and judge by the breakdown voltage of the paint film. The performance is analyzed and judged by two tests of normal state and cold state breakdown voltage.
¡ñContinuity of paint film (pinhole). Check the paint film pores with a certain length of test material. This item is tested by the high pressure paint film continuity tester.
¡ñFlexibility (flexibility). When winding or elongating, judge whether the paint film is cracked or whether pinholes are generated.

As one of the main raw materials of winding wire, enameled wire enamel is a unique insulating material for enameled wire and an essential core material. The demand for enameled wire paint also indirectly reflects the demand for winding wire to a large extent, and most varieties of enameled wire paint are almost exclusively produced for enameled wire. In the past ten years, the production of global enameled wire enamel has gradually shifted to Asia. The fundamental reason is that the main demand is in Asia, and the most important one is China. China is currently the world’s largest producer and seller of enameled wire and enameled wire paint.
It is estimated that the total annual demand for enameled wire paint in the world is about 300,000 to 350,000 tons, and China is about 200,000 to 250,000 tons.