False Part Thermal Sensor for Plastic Welding Quality
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for evaluating the welding quality of plastic parts, such as polyethylene, during electrofusion or butt welding are inadequate as they are either invasive, time-consuming, or provide limited reproducibility and reusability, and fail to accurately measure the temperature field evolution at the interface between the parts.
Innovation Solution
A device comprising a false part with thermal sensors that mimics the first part to be welded, made of a non-weldable material with thermal characteristics close to the actual part, allowing for the measurement of temperature evolution during welding without being welded, enabling reusable and reproducible evaluation of welding quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If thermal sensors are integrated into the surface of parts to be welded by drilling and blocking, then measurement precision is improved, but device complexity and time consumption increase significantly
Solution Approach 1:
The patent uses a false part that replicates the geometric and thermal characteristics of the actual part to be welded. This copy is instrumented with thermal sensors and placed in the welding position instead of the real part, allowing temperature field measurement without modifying the actual part. The false part serves as a faithful reproduction that maintains all relevant thermal properties while enabling non-invasive measurement.
Solution Approach 2:
The false part acts as an intermediary between the welding process and the thermal sensors. Instead of directly attaching sensors to the actual part (which would require drilling and blocking), the sensors are mounted on the false part that mediates the measurement process. This intermediary approach allows temperature field measurement during welding without the complexity of direct sensor integration into the actual part.
2Measurement precision
If thermal sensors are attached to the welding interface, then measurement precision is improved, but reproducibility and reusability deteriorate due to trapped sensors during welding
Solution Approach 1:
The false part is a reusable copy that can be removed after welding without being consumed or damaged. Multiple false parts can be prepared in advance, each instrumented with thermal sensors, allowing repeated welding operations with consistent measurement conditions. The copy approach ensures that the actual part remains untouched and that measurement setups can be reproduced across different welding operations.
Solution Approach 2:
The measurement system is segmented into a separate false part that can be independently prepared, used, and replaced. This segmentation allows the thermal sensors to be mounted on the false part without concern for being trapped during welding, as the false part itself is designed to be removable or replaceable after the welding process completes.
3Ease of operation
If glues are used to maintain the film between parts to be welded, then ease of operation is improved, but reliability deteriorates due to glue incompatibility with temperature range
Solution Approach 1:
The false part approach eliminates the need for adhesives entirely. The false part is mechanically positioned and fixed in place during welding, and can be removed afterward without residue or damage. This copy-based method avoids the fundamental incompatibility between organic adhesives and high-temperature welding environments, providing both ease of positioning and temperature range compatibility.
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 solution provides a non-invasive, reusable, and reproducible method for evaluating the temperature field evolution during welding, allowing for the assessment of welding quality and ensuring the integrity of the weld, which is essential for maintaining the network's integrity and preventing manufacturing deviations.
Implementation Method 1
the false part being made of a material that cannot be welded during the operation and has thermal characteristics close to those of the first part
Implementation Method 2
a heating insert or a heating sheet, constituted like a knit or winding of resistive wires, is placed between the two plastic parts to be welded by fusion, the sheet being electrically powered by a controller adjustable in voltage or intensity current
Data Source
Figure 1~2
AI summary
The present invention relates to the field of inspection devices and methods for assessing and diagnosing the weld between a first component and a second component (2) both made of plastic used for the distribution of fluids and relates more specifically to a device (1) for measuring the evolution in a range of temperatures during an operation of welding together the first component and the second component (2), the device (1) comprising a dummy component (10) indicative of the first component and a set of heat sensors (12) fixed and distributed on at least part of a contact surface (3) via which the dummy component makes contact with the second component (2), said dummy component being made of a material that cannot be welded under the conditions of the welding operation exhibiting thermal characteristics similar to those of the first component. The present invention also relates to an associated method for checking the quality of the weld between the first component and the second component.