Pin Sonotrode Ultrasonic Welding for Plastic Surface Protection
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Solution Overview
Problem
Conventional ultrasound welding processes for plastic components, such as bumpers with integrated sensors, face issues with energy input causing melting and impairment of the optical appearance, leading to suboptimal results.
Innovation Solution
A step-by-step ultrasound welding process using a sonotrode with at least two pins, where each welding step occurs in an area already stressed and relaxed by the previous step, with controlled energy input and spatially close steps along a defined welding path, allowing material relaxation time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ultrasonic welding processes are used with smooth contact surfaces to maximize contact area, then welding reliability is improved, but the optical appearance of the component is impaired due to melting and energy input on the visible side
Solution Approach 1:
The sonotrode is designed with pins that concentrate ultrasonic energy at specific localized contact points rather than distributing it across the entire contact surface. This allows the welding area to have high energy input for reliable bonding while the surrounding visible areas remain unaffected and maintain their original optical appearance.
Solution Approach 2:
The continuous contact surface is segmented into discrete pin contact points. Instead of using a smooth continuous contact surface that distributes energy broadly, the sonotrode uses multiple pins that create discrete welding zones, isolating the energy input to specific locations that do not affect the overall visual appearance.
2Strength
If high energy input is used during ultrasonic welding to ensure strong bonding, then welding strength is improved, but unwanted welding and melting occur in edge areas and surrounding regions
Solution Approach 1:
The pin design concentrates ultrasonic energy precisely at the pin contact points where welding is desired. The energy distribution is highly localized, creating strong bonds at the pin locations while preventing energy spread to edge areas and surrounding regions that would cause unwanted welding or melting.
Solution Approach 2:
The pins act as intermediary elements between the sonotrode and the component surface. They mediate the energy transfer by concentrating it at specific points, allowing strong welding at the contact points while preventing direct energy transmission to surrounding areas that would cause harmful effects.
3Manufacturing precision
If step-by-step welding is performed with multiple pins along a welding path, then control over energy distribution is improved and optical appearance is preserved, but welding time increases
Solution Approach 1:
The welding process is segmented into multiple discrete steps, with each pin creating a weld at a specific location along the welding path. While this provides precise control over energy distribution, the sequential nature of the process increases the total welding time compared to simultaneous multi-point welding.
Solution Approach 2:
The sonotrode moves along the welding path in periodic steps, with each step corresponding to a welding operation at a specific pin location. This periodic action allows for controlled energy distribution but inherently increases process time due to the repeated stop-and-weld cycle.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables a strong connection with minimal energy input, reducing the risk of unwanted welding and preserving the optical appearance of the components.
Implementation Method 1
a method for ultrasonically welding two plastic components using a sonotrode, wherein the energy for welding is introduced into the plastic components via at least two pins of the sonotrode
Implementation Method 2
the energy for welding is introduced into the plastic components via one or more pins of the sonotrode
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
The invention relates to a method for ultrasonic welding of two plastic components (1, 2) using a sonotrode (6), wherein the energy for welding is introduced into the plastic components via at least one or more pins (7) of the sonotrode (6), wherein the two plastic components (1, 2) are welded together step by step, wherein each subsequent welding step takes place in an area (9) that is already stressed and relaxed by the preceding welding step.