(I) significance of defective product maintenance

In the production of electric heating elements, it is inevitable to produce defective products. Due to the inconsistent technology and management level of each factory, the quantity of defective products varies greatly. In some enterprises with strong technical force and high management level, the secondary product rate can be controlled below 0.5%, while in some poor enterprises, the secondary product rate is 3-5%. If the defective products in production can be repaired and the percentage of defective products can be reduced to a certain extent, this is the goal pursued by every enterprise. Reducing defective products can not only reduce the losses of the enterprise, reduce costs and improve the economic benefits of the enterprise, but also save raw materials, auxiliary materials, labor force and meet the requirements of delivery time.

(II) possibility of repairing defective products in the production of electric heating elements

Generally speaking, it is difficult to repair defective electric heating elements after they are made. However, in practice, we have found that some of them can be repaired.

1. What kinds of defective electric heating elements can be repaired:

When some of the following problems occur in the filling material of electric heating elements - magnesium powder, making the elements defective, such electric heating elements have the possibility of maintenance.

A. the raw magnesium powder is of good quality. Due to uneven mixing or other reasons during modification, after the electric heating element is made, its moisture resistance is low, about 100m Ω. When the element is placed in the air, the resistance will continue to drop. Red ink is injected into the two ends, and the ink can be absorbed. The pipe mouth at the two ends is cut open, and the absorbed red ink is more than 2mm.

B. magnesium powder is slightly damaged during the processing of electric heating elements:

For example, the two end flange welding of the Youting pipe, the water dispenser pipe, the end welding of the water cooker pipe, and the pickling (hydrochloric acid, nitric acid) and electroplating solution immersion during the electroplating process.

C. other conditions: for example, the electric heating pipe has not been heated or has been heated after pipe making, but the temperature is too low or reached, but the heating time is too short, etc.

2. What causes defective electric heating elements that cannot be repaired

A reasons for magnesium powder: poor quality of raw magnesium powder, high content of ferromagnetic substances and other harmful impurities, low density or uneven density.

B pipe material defects: such as cracks, burrs in the pipe, bubbles, shrinkage cavities, slag inclusions, etc.

C. problems occurred during pipe manufacturing: such as broken electric heating wire, eccentric electric heating wire and lead out rod or hitting the wall.

Article source: heat pipe manufacturerhttp://www.gdtamman.com