There are several ways to embed copper nuts into plastic parts, several methods such as pre-embedded mold, hot pressing, ultrasonic pressing, cold pressing and self-tapping.
1. Injection nut
Before injection, the copper nut is placed in the mold for integral injection molding. Due to the different shrinkage coefficients of nuts and plastics, it is easy to produce residual stress: and the operating environment is harsh and the efficiency is low.
2. Hot pressing nut
The hot-melt process is to heat the copper nut to a certain temperature to soften the plastic and then press it in. The internal stress generated by this method is small, and the torsional force of the nut is also very good. Hot melt embedding is the most common and most common method of embedding. Generally, a hot melt machine or a manual electric soldering iron is used for operation.
3. Ultrasonic nut
Ultrasonic implantation is a method that uses ultrasonic vibration to make the friction between the nut and the surface of the workpiece increase the temperature transmitted to the interface. When the vibration stops, the workpiece cools and sets at a certain pressure at the same time.
Because the ultrasonic implantation will release energy instantly, the impact on the nut is large, and the structure of the nut, especially the threaded part, is easily damaged during the implantation process. It is recommended that nuts below MI. 6 should not use ultrasonic implantation.
4. Cold pressing
Instead of heating the nut, the nut is directly pressed into the rubber column using pressure. The torsion force and tensile force of the nut implanted in this way are low, which is suitable for occasions with little stress.
Use a wrench to screw in the nut, which is equivalent to tapping a thread on the plastic part.