Ultrasonic Fastening of Thermoplastic Edge Structures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for attaching objects to lightweight construction elements, such as sandwich boards, are inefficient and require costly pre-treatment or specialized tools, and often compromise the structural integrity of the boards.
Innovation Solution
A method using an ultrasonic device with a sonotrode to couple vibrations into the object, causing liquefaction of thermoplastic material at the interface with the cover regions, allowing for secure fastening without pre-treatment and minimal depth penetration, using mechanical or thermal energy to achieve a stable connection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional fastening methods are used on lightweight construction elements, then secure attachment can be achieved, but costly pre-treatment and specialized tools are required
Solution Approach 1:
The patent applies ultrasonic vibration through a sonotrode to the thermoplastic material at the interface between the object and cover region. This mechanical vibration causes the thermoplastic material to liquefy locally, enabling it to flow into the cover region and form a secure mechanical interlock upon cooling, achieving reliable attachment without pre-treatment channels or grooves
Solution Approach 2:
The patent changes the physical state of the thermoplastic material from solid to liquid through ultrasonic vibration-induced heating, and then back to solid upon cooling. This parameter change enables the material to adapt to the cover region geometry and form a strong bond, eliminating the need for specialized pre-treatment tools
2Reliability
If conventional fastening methods are used on lightweight construction elements, then attachment can be achieved, but the structural integrity of the boards is compromised
Solution Approach 1:
The patent applies ultrasonic energy locally at the interface region between the object and cover region, causing liquefaction only in this specific area. The rest of the lightweight construction element remains unaffected, preserving its structural integrity while achieving secure attachment at the bonding interface
Solution Approach 2:
The thermoplastic material serves as an intermediary substance that is introduced into the cover region. Through ultrasonic-induced liquefaction, it flows into and bonds with the cover region, creating a strong mechanical interlock that secures the object without compromising the overall structural integrity of the lightweight construction element
3Reliability
If deep penetration fastening is used, then secure attachment is achieved, but significant material removal is required
Solution Approach 1:
The ultrasonic vibration concentrates energy at the interface region, causing localized liquefaction of the thermoplastic material without requiring deep penetration or significant material removal. The vibration energy is dissipated through internal friction and friction at the interface, melting the material in place to form a bond
Solution Approach 2:
The thermoplastic material itself serves as both the bonding agent and the medium for energy absorption. The material's internal friction and friction at the interface with the cover region generate the heat needed for liquefaction, eliminating the need for external heating or significant material removal
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
Enables efficient and cost-effective fastening of objects to lightweight construction elements with minimal material removal and no need for pre-treatment, maintaining structural integrity and allowing for flexible orientation of the construction elements.
Implementation Method 1
The supplying of energy may take place by a sonotrode, through which vibrations are coupled into the object. The vibrations can be coupled into the object in such a way that they are transmitted through the latter to an interface with the cover regions and the liquefaction takes place as a result of the friction between the cover region and the thermoplastic material and/or internal friction of the thermoplastic material
Implementation Method 2
the liquefaction takes place as a result of the friction between the cover region and the thermoplastic material and/or internal friction of the thermoplastic material
Implementation Method 3
The supplying of energy may alternatively also be brought about in some other way, mechanically, by heating or by radiation coupled in, for example, through the object, which is absorbed at the roughened or for some other reason absorbent interface between the object and the cover region
Data Source
AI summary
A method of fastening an edge structure to a construction element includes providing the construction element, being a planar structure with two cover regions and a middle region between the cover regions; providing the edge structure being continuously extended, the edge structure having contact surfaces with a thermoplastic material shaped to lie against the cover regions in an outer surface of the construction element, and, opposite the contact surfaces, a coupling-in surface for coupling energy into the edge structure; coupling energy into the edge structure and pressing the contact surfaces against the cover regions until at least a portion of the thermoplastic material is liquefied and pressed into the cover regions; and repeating or continuing the steps of coupling and pressing until the edge structure is attached to the building element at a plurality of discrete locations or over an extended region along an edge of the construction element.