Hot - Melt Brass Threaded Inserts For Improve Plastic Connection Strength

Hot - Melt Brass Threaded Inserts For Improve Plastic Connection Strength

Description

1. Improve the connection strength between plastic parts.

In general, the screw connection between plastic parts is usually connected by self-tapping screws. The inner hole of the plastic screw column can be formed by injection molding at one time, and the subsequent self-cutting of the self-tapping screw is used to generate the threaded connection, which is convenient and fast; however; When the connection strength between plastic parts needs to be improved, the screw must be tightened with sufficient torque to generate sufficient axial tension between the main part and the screw thread to prevent loosening. However, the inner hole of the plastic screw column If the thread cannot withstand a large enough load, slippage or looseness will occur, which naturally cannot meet the required connection strength.

The metal thread can prevent the thread from deforming under the entire load, so the copper nut can significantly improve the connection strength in the plastic part.

2. The plastic parts need to be disassembled many times.

Some products require maintenance or require frequent disassembly and assembly of certain parts. The use of copper nuts embedded in the plastic parts can achieve repeated disassembly and assembly without losing the integrity of the thread. This is also self-tapping. The screw column is incomparable.

3. Replace metal parts with plastic parts.

Although metal parts are easy to obtain high-strength threaded connections, their processing and material costs are high, and their specificity is high. They are not suitable for cost-required and lightweight products. Therefore, copper nuts can be embedded in the plastic parts. Meet this demand.

Specification

Several ways of implanting plastic inserts

Hot melt implantation is also called hot pressure implantation. That is, the insert (usually a copper insert) is heated by an electric soldering iron (to 200-250 degrees), the reserved hole wall of the plastic part is heated and becomes soft, and then the insert is pressed at a uniform speed.

Mold implantation is to fix the metal insert on the thimble (PIN needle) in the mold before the injection molded part is molded, and then the injection molding machine closes the mold and injects the glue. After the mold is opened, the insert and the cooled plastic part are integrated.

Directly press in, the insert does not need to be heated, through the unique form of insert, the punch directly presses the insert into the plastic reserved hole, which is generally suitable for thermosetting plastic. The outer circle of the directly pressed insert has a chamfered edge to prevent it from falling out.

Slotting and pressing do not require heating, and it is divided into two types. One is chamfered. The preset plastic hole is pressed by a punch. Due to the open groove at the bottom of the insert, external force acts on the bottom of the hole, and the thread hole diameter becomes smaller. , Form a certain clamping force on the screwed bolt to prevent the insert from falling out. The second is threaded screwing. The shape of the insert has a sharp self-tapping thread. The insert is screwed into the plastic hole by screwing, similar to a threaded bushing.

Which method is better?
Generally speaking, different implantation methods are selected according to different application conditions. Plastic parts with a simple and neat appearance and only one or no more than two inserts are embedded. From the perspective of efficiency, molds are used for implantation. One plastic part is embedded with multiple inserts. Obviously, hot melt implantation is more efficient. Thermosetting plastics cannot be heated, and cold pressing is better. Harder engineering plastics can be pressed in by slotting.

Option

1. The crystalline plastic is relatively insensitive to stress, so all kinds of nuts can be applied

2. Amorphous plastic is very sensitive to stress. When choosing the nut type, avoid sharp knurling. Special care should be taken for those plastic parts that need to be electroplated for the screen. Pickling of the plastic parts with embedded nuts will cause serious cracking. It is best to first electroplating and embed the nuts.

3. Thermosetting plastics are not suitable for hot-melt and ultrasonic implantation of nuts. If necessary, you can choose precise and sharp knurled nuts to press in.