Method of heat staking and ultrasonic threaded insert installation in plastics

The  Brass press handle is electrically heated to 80~90 degrees (due to different substrates, temperature control is also different, generally about 10 degrees lower than the melting point of the substrate), contact with the  Brass nut, and the temperature of the  Brass nut rises.

Heat staking/ultrasonic installation is the most common and most common embedding method, which is generally buried by hot melt machine and manual electric soldering iron

1, The Brass press handle is electrically heated to 80~90 degrees (due to different substrates, temperature control is also different, generally about 10 degrees lower than the melting point of the substrate), contact with the Brass nut, and the temperature of the Brass nut rises.

2, The Brass nut into the plastic parts

3, During heat staking and ultrasnoc process

Other installation methods of the nut

Injection nut

Injection Molding embedment generally has strict requirements for the hole diameter of the nut, and the hole diameter is controlled within 0.05mm, because the product is fixed by the Molding Pin and placed in the injection molding mold, the hole diameter of the nut is controlled by the size of the PIN of the injection molding machine.

Ultrasonic nut:

Ultrasonic embedding is a kind of ultrasonic vibration, so that the nut and the workpiece surface and the friction between the internal molecules and the temperature to the interface to increase, when the temperature reaches the softening temperature of the workpiece itself, the nut is embedded in the rubber, when the vibration stops, the workpiece at the same time under a certain pressure cooling and setting.

1. The d size is the nut base, also known as the guiding positioning part, which is matched with the plastic part C before embedding, so the d part at the bottom of the nut is smaller than the inner diameter C of the plastic to facilitate positioning

2, the D size is the outer diameter of the nut, which matches the size of the plastic inner aperture C, the general plastic inner aperture of the phone nut is about 0.25-0.3mm smaller than the outer diameter of the nut;

3, L size is the length of the nut, it is compatible with the depth of the plastic hole Y size, the general plastic hole depth is 0.5-1.0mm larger than the height (length) of the screw for storage;

4, W is the thickness of the plastic hole wall, the general plastic hole meat thickness is more than 0.8-1.0mm, the larger the nut size, the larger the meat thickness.

Due to the shallow depth of the plastic hole, such as the choice of double twill nuts, in the nut size ratio deployment, especially on the emboweling, the emboweling section difference is shorter, such nuts buried in the plastic, emboweling eat plastic surface too little plastic, will produce insufficient torsion tension phenomenon, so it is generally recommended that the plastic reservation hole depth is set at more than 2.5mm, The nut size length is generally recommended to be more than 2.0mm. Improvement plan: Similar to this situation, in the case that the customer is not convenient to change the mold, it is recommended to change the nut shape to monoclinic BS1, as shown in the right figure, which will increase the difference between the embossment section and the plastic surface of the embossment, thereby increasing the torsion tension.

In addition, if the plastic hole overflows, burst:

Due to the choice of the style nut on the left, after embedding the plastic, A1 and A2 expand, but B shrink sharply, resulting in plastic crowding difficulties, the upper and lower ends of the nut are prone to overflow phenomenon, which seriously affects the product view;

Improvement plan: With the "C" part as the guide positioning, so that the nut can be securely placed in the plastic hole, improve the efficiency and yield, due to the addition of the C-end guide part, A2 to squeeze out a certain amount of rubber, but also reserved enough rubber for the A1 part, because A1, A2 part is 90° intersection Angle of 45 ° twill, and can form a high-strength node at the intersection Angle. The torsional force on the impedance circumference greatly increases the torsional tension.