The structural design of plastic parts must first consider the following points:
(1) The size of the weld (that is, to consider the required strength)
(2) Whether water tight, air tight
③ Whether perfect appearance is required
(4) Avoid plastic melting or synthetic overflow
Whether it is suitable for welding head processing requirements

Welding quality can be achieved through the following controls:
1) material
The structure of plastic parts
The position and design of welding line
④ The size of the welding surface
The position and tightness of the upper and lower surfaces
⑥ Contact surface of welding head and plastic parts
Smooth welding path
⑧ Bottom mold support

In order to achieve perfect, repeatable fusion welding, three main design directions must be followed:
(1) The initial contact between the two surfaces must be small in order to concentrate the required energy and minimize the total energy required (i.e. connection time) to complete the welding.
(2) Find suitable fixation and alignment methods, such as; Plastic parts of the socket, steps or tongue-and-groove and so on.

The welded surfaces surrounding the connection interface must be uniform and in close contact with each other. If possible, try to keep the contact surfaces on the same plane so that the energy transfer is consistent. Ultrasonic welding machine first to ensure that the injection mold is conducive to the welding of ultrasonic welding machine, only in this way to achieve high welding requirements, so the premise of ultrasonic welding machine welding is the design of injection mold. A good injection mold is a necessary condition for welding.