Today, Xiaobian for you to analyze the work of ultrasonic plastic welding machine, how to design solder joints and welding surface, only master this skill, in order to better use the ultrasonic plastic welding machine for production work.
1. Solder Joint Design
The design of welding joint is to design a reasonable joint for ultrasonic spot welding plastic material. It is required that the continuous strength of the weld joint structure should meet certain requirements. At the same time, the appearance should be as beautiful as possible. The structure of the welded joint is related to the thickness of the welded joint. Let the thickness of the welded joint be T, and the shape of the welded joint be a raised ring. The inner diameter of the ring is 1.5T and the depth of the blind hole is 1.5T. A ring-shaped melting connection zone is formed in the range of the diameter around the blind hole being 3T.
2. Design of Welding Surface
In order to concentrate energy, shorten welding time and improve welding quality, the design of welding surface is very important. Here is a brief introduction of the centralized design method.
(1) conductive triangular welded surface
On one side of the two plastic joints, along the welding surface, add a small triangular flange. The flange gathers the ultrasonic vibration at the sharp corner of the triangle, which reduces the contact area of welding and forms concentrated ultrasonic energy. Dissolved plastics flow evenly over the welded surface, producing strong afterforce, and greatly reducing the welding time, the wall thickness of the welded surface should be less than 2.5mm in order to achieve better results.
(2) Step Welding Surface
The step and triangle flange make the welding force stronger. When the flange material melts, it flows into the reserved void, which can produce larger shear force and tensile strength. This design can also avoid tangible welding on the surface.
(3) Peak and valley welded surfaces
A reinforced triangular flange welded surface. There should be clearance between the two sides of the peak and valley to allow easy assembly of plastic parts, while allowing melted materials to have flowing space.
(4) Shear welded surface
Whether rectangular or circular parts, this welding surface has a high sealing effect. Because a large number of materials need to flow, high-amplitude and high-energy ultrasonic wave is needed, concave holes should be reserved between the welded surfaces to accommodate a proper amount of molten plastic, so as not to spill out and produce hair. The result of vertical phase extrusion along the wall of two plastic parts completely eliminates the gap or gap. This kind of welding surface is especially suitable for materials with crystalline structure and instantaneous melting characteristics. When the welding depth is 1.25 times the wall thickness, the strength is higher.
In a word, the design of solder joint or solder surface is an important part of ultrasonic plastic welding. It should be designed according to the specific welding parts and requirements. The unreasonable design will lead to problems such as weld overflow and melt material, and the welding strength will also be affected.