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What was the challenge or problem to be solved?
In industrial environments where electrical systems are critical, cable reliability has a direct impact on operational continuity and final product quality. Seemingly minor failures, such as insulation breakage, can lead to rejections, production downtime, and increased costs associated with poor quality.
In this context, an industrial company identified recurring incidents during assembly, linked to insulating material failure in certain cables. The primary need was to understand the root cause of the problem and establish objective criteria to improve quality control of electrical cables and supplier validation. Defect detection in electrical cables thus became a strategic priority, driving the need for a more rigorous and systematic approach to material analysis.
Quality control problems with electrical cables in production
The problem originated in the area of electrical cable quality control, where certain batches, despite meeting initial technical specifications, exhibited unexpected behavior when subjected to real assembly conditions. This discrepancy between specification and performance revealed a clear limitation in the traditional quality control methods applied up to that point.
Visual, dimensional, or even basic electrical inspections were unable to detect this type of defect, since the failure was linked to the mechanical behavior of the material under stress. This meant that potentially defective materials passed initial checks and only failed in advanced stages of the production process, generating rejections and rework.
The absence of visible defects does not guarantee correct material behavior, as many failures only manifest under real mechanical stress during assembly or in service.
The lack of adequate analytical tools made early identification of the problem difficult, forcing the company to accept a high level of uncertainty in the validation of its supplies. This situation directly impacted operational efficiency and production process stability.
In this context, it became necessary to evolve toward a more robust approach, based on advanced material characterization and comparative analysis, to detect non-obvious differences and establish objective acceptance criteria.
Defect detection in electrical cables through OK/NOK comparative analysis
The objective was defined in terms of defect detection in electrical cables, using a methodology based on direct comparison between conforming (OK) and non-conforming (NOK) samples. This approach allows real differences to be identified between materials that, on the surface, meet the same technical specifications.
The OK/NOK comparison makes it easier to isolate critical variables, eliminating the noise associated with absolute analyses and focusing the study on relevant differences. This approach is particularly useful when defects are not obvious or when multiple possible causes exist.
OK/NOK comparative analysis turns a diffuse problem into measurable differences, enabling more objective, evidence-based decision-making.
Furthermore, this approach provides a solid experimental foundation, since each detected difference can be assessed in terms of its real impact on material behavior. This reduces reliance on subjective interpretations or incomplete information provided by the supplier.
The ultimate goal was to build a robust technical criterion capable of distinguishing between valid and invalid materials, facilitating decision-making in procurement processes, supplier validation, and incoming quality control.
Cable insulation breakage as a material problem
Insulation breakage in cables was the core technical problem identified. This type of failure is typically related to variations in polymer formulation, differences in additive proportions, or deviations in the material’s manufacturing process.
One of the main challenges was that the failure did not manifest immediately or under standard test conditions, but rather during cable handling or installation. This indicated that the problem was associated with specific mechanical properties, such as ductility or resistance to deformation.
The polymer materials used as insulators are particularly sensitive to small variations in composition, which can translate into significant changes in mechanical behavior. This sensitivity adds complexity to the analysis, as subtle differences can have relevant consequences.
From INFINITIA’s perspective, the problem was approached as a case of failure analysis in electrical cables, where the key was to correlate material characteristics with behavior under real-world conditions, validating hypotheses through experimental evidence.
How was it addressed or what was the solution?
To address the problem, a strategy was defined based on a combination of analytical techniques and functional testing, with the aim of correlating material composition with mechanical behavior. This approach makes it possible to understand not only what changes, but how those changes impact performance.
The project was structured as an iterative process of analysis and validation, where each result allowed the initial hypotheses to be refined. This methodology supports evidence-based technical decision-making and improves quality control of electrical cables.
Characterization of insulating materials using TGA and DSC in polymers
The first step involved the characterization of insulating materials, using techniques such as TGA and DSC in polymers to analyze their thermal behavior and detect possible differences in composition.
These techniques allow parameters such as thermal stability, material transitions, or the presence of fillers to be evaluated, providing indirect information about polymer formulation. This type of analysis is especially useful when detailed supplier information is not available.
Thermal analysis makes it possible to identify deviations that are not visible through more conventional techniques, acting as an initial diagnostic tool for detecting potential causes of failure. It also facilitates direct comparison between samples.
This approach was selected for its ability to provide relevant information at a moderate level of complexity, enabling a first analytical baseline to be established before moving on to more specific testing.
Failure analysis in electrical cables using tensile testing
Once potential differences in material composition had been identified, they were validated through tensile testing of insulation, as part of the failure analysis approach for electrical cables.
These tests allow key mechanical properties to be quantified, such as tensile strength, elongation at break, and material behavior under load, parameters that are fundamental to understanding insulation performance under real-world conditions.
The mechanical properties of the insulation determine its behavior during assembly, where small variations in ductility can lead to critical failures under real conditions of use.
The results obtained showed significant differences between OK and NOK samples, particularly in terms of ductility. The defective samples exhibited a lower capacity for deformation before breaking, which explained their brittle behavior during assembly.
The correlation between thermal and mechanical results validated the initial hypothesis, establishing a clear relationship between differences in material formulation and the failure observed in production.
Supplier validation and quality control improvement for electrical cables
As a result of the study, objective criteria were obtained for industrial supplier validation and improved quality control of electrical cables.
The OK/NOK material comparison enabled a solid technical basis for material acceptance or rejection, reducing uncertainty in decision-making and improving the robustness of the procurement process.
In addition, the possibility of failure reproduction in the laboratory provides a key tool for validating hypotheses and anticipating problems before they arise in production, enabling a preventive rather than reactive approach.
The work carried out improved the reliability of the final product and reduced operational incidents. However, depending on the level of depth required, this type of analysis can be complemented with additional studies aimed at fully determining the root cause.
Contact us to learn more about how we can help you improve the quality and reliability of your electrical cables.
