Determining the initial state of a sample is a crucial prerequisite for ensuring data comparability and result validity in accelerated aging tests. The initial state serves as a performance baseline and directly affects the accuracy of assessing changes after aging.
1. Appearance and Sensory Status Recording
Before testing, conduct a systematic appearance inspection of the samples to establish a visual baseline.
Inspection Items:
Color, gloss, transparency
Scratches, bubbles, deformation, cracks, or contamination
Packaging integrity (e.g., sealing edges, label placement)
Recording Method: Text description + high-resolution photo archiving to ensure traceability
Standard Basis: GB/T 18244-2022 requires at least 3 sets of test specimens to be prepared, with the sampling point ≥20mm from the material edge.
2. Initial Value Determination of Physical Properties
Based on product type, test and record key physical parameters as a control baseline.
|
Product Type |
Initial Performance Test Items |
|
Plastics/Rubber |
Tensile strength, elongation at break, hardness |
|
Coatings/Coatings |
Adhesion, gloss, film thickness |
|
Medical Packaging |
Sealing strength, burst pressure, microbial barrier performance |
|
Electronic Components |
Insulation resistance, leakage current, functional power-on test |
|
Photovoltaic Modules |
Maximum output power, open-circuit voltage, short-circuit current |
|
Recommendation |
Test at least 3 parallel samples per batch and take the average to reduce error. |
3. Establishing Chemical and Molecular Structure Benchmarks
For polymer materials, pharmaceuticals, or cosmetics, initial chemical state needs to be obtained through instrumental analysis.
Common Methods:
FTIR Infrared Spectroscopy: Identifies characteristic functional groups (e.g., C=O, OH)
DSC/TGA Thermal Analysis: Records glass transition temperature (Tg) and thermal decomposition temperature
HPLC/GC-MS: Determines the content of active ingredients and impurity levels
Purpose: To provide a comparative basis for whether oxidation, hydrolysis, or degradation occurs after aging.
4. Environmental Pretreatment and Conditioning
To eliminate the influence of storage and transportation, environmental conditions need to be standardized before testing. Standard Conditioning Conditions: 23℃ ± 2℃, 50% ± 5%RH, for at least 24 hours.
Purpose: To allow samples to reach hygroscopic or thermal equilibrium, avoiding initial fluctuations that could interfere with test results.
Industry Practice: Conditioning is mandatory before testing medical device packaging.
5. Sample Grouping and Labeling Management: Scientific grouping and clear labeling are fundamental to ensuring traceability during the testing process.
Operational Points: Group samples by test time point (e.g., day 0, day 7, day 14, etc.). Each sample should be uniquely numbered, and the batch number, production date, and sampling location should be recorded. Store samples in a clean, light-protected environment to prevent pre-aging.
6. Data Archiving and Report Generation: All initial data should be formally recorded as part of the test report.
Archived Contents: Original test data sheet; Image data (photos, spectra); Testing equipment model and calibration information; Operator signature confirmation.
Compliance Requirements: YY/T 0681.1-2010 explicitly requires recording sample initial state information.
Summary: Determining the initial state is not only the "starting point of testing" but also the anchor point of the entire accelerated aging data chain. Only by establishing accurate benchmarks across multiple dimensions-appearance, physical, and chemical-can aging trends be scientifically assessed, supporting lifetime prediction and quality improvement decisions.
