Lateral Sonotrode Welding for Adhesive-Free Container Bottom Joining
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Solution Overview
Problem
The existing methods for producing containers with bottoms, particularly in the food and pharmaceutical sectors, face challenges such as low cycle times, high adhesive usage costs, and inadequate accessibility for the main body.
Innovation Solution
A sonotrode for friction welding is used to create a reliable connection between the main body and the bottom of containers, eliminating the need for adhesives by introducing joining energy laterally into the joining zone between the two parts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If adhesive is used to connect the main body with the bottom, then the connection is achieved, but the cycle time increases and production costs increase
Solution Approach 1:
The patent replaces the chemical bonding mechanism (adhesive) with a mechanical-thermal bonding mechanism (friction welding). The sonotrode introduces joining energy laterally into the joining zone, creating friction heat that melts and fuses the thermoplastic materials directly, eliminating the need for adhesive application and drying time.
Solution Approach 2:
The sonotrode utilizes ultrasonic vibration to generate friction heat in the joining zone. The lateral introduction of joining energy through the vibrating sonotrode creates intense localized friction between the main body and bottom, rapidly heating and melting the thermoplastic materials to form a strong weld joint.
2Reliability
If adhesive is used to connect the main body with the bottom, then the connection is achieved, but the production costs increase
Solution Approach 1:
The patent replaces the chemical bonding mechanism (adhesive) with a mechanical-thermal bonding mechanism (friction welding). This eliminates the need for purchasing, storing, and applying adhesive materials, as well as reducing waste disposal costs, while maintaining strong connection reliability through direct material fusion.
Solution Approach 2:
The invention extracts and eliminates the adhesive from the production system entirely. By using friction welding, the process removes the adhesive application step, the drying/ curing step, and all associated material costs, simplifying the manufacturing process and reducing overall production costs.
3Reliability
If adhesive is used to connect the main body with the bottom, then the connection is achieved, but the accessibility to the main body is not sufficient
Solution Approach 1:
The sonotrode's ultrasonic vibration generates friction heat directly at the joining interface through lateral energy introduction. This method requires minimal accessibility space compared to adhesive application equipment, as the sonotrode can be positioned laterally and deliver energy directly to the joining zone without requiring extensive tooling access.
Solution Approach 2:
The patent introduces joining energy laterally into the joining zone rather than requiring axial or end-access application. The sonotrode approaches the joining zone from the side, delivering ultrasonic vibration energy laterally to the interface between main body and bottom, thereby improving accessibility for containers with restricted end access.
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 method significantly reduces production costs, increases cycle efficiency, and ensures a strong, adhesive-free connection, while also simplifying maintenance and reducing the required space for the welding device.
Implementation Method 1
A sonotrode (10; 110) for friction welding of at least two joining parts (1; 3), which are at least partly made of a weldable material
Implementation Method 2
a basic body (12; 112) with a first axial end (14; 114) and an opposite second axial end (16; 116), with the basic body having a central longitudinal axis (18) extending through the first and the second axial end and along which the sonotrode is movable in operation or along which an excursion of the sonotrode can take place in operation
Data Source
AI summary
A sonotrode for friction welding of at least two joining parts, which are at least partly made of weldable material, in particular plastic material. The sonotrode comprises a basic body with a first axial end and an opposite second axial end, with the basic body having a central longitudinal axis extending through the first and the second axial end and along which the sonotrode is movable in operation. Furthermore, adjacent to the second axial end, a work surface is provided at the basic body laterally with respect to the central longitudinal axis, which in operation is contactable to one of the joining parts, so that joining energy is laterally introducible into a joining zone between the joining parts. The work surface encompasses the basic body circumferentially, preferably without interruption, and comprises a structure that is adapted to a shape of at least one of the joining parts.