The determination of ash content in plastic rubber is mainly used to evaluate the quality, composition, and performance of materials by burning samples at high temperatures to determine the content of residual inorganic substances. The determination of ash content in plastics and rubber is a key testing item for evaluating the content of inorganic impurities (such as fillers, catalyst residues, inorganic salts, etc.) in materials, which directly affects the purity, processing performance, and application scenarios of materials (such as food contact, electronic insulation, etc.).
The working principle of the plastic rubber ash analyzer is mainly based on thermogravimetric analysis and combustion decomposition technology. Here are the specific principles:
Principle of thermogravimetric analysis: By burning the sample at high temperatures, organic components are decomposed (such as carbon, hydrogen, oxygen and other elements are converted into gases such as carbon dioxide and nitrogen oxides), and the remaining inorganic substances (such as minerals and metal oxides) are formed into ash. Calculate the ash content by measuring the changes in sample quality before and after combustion.
Combustion decomposition technology
Direct calcination method: Place the sample in a high-temperature furnace, set the temperature (usually 550-950 ℃), and residual inorganic substances after the combustion of organic matter.
Sulfuric acid treatment method: After combustion, the residue is treated with sulfuric acid to convert inorganic substances into sulfates, and then calcined at high temperature to constant weight.
Secondary calcination method: After high-temperature combustion and cooling, calcine again for 30 minutes to ensure the decomposition of inorganic substances, and then weigh the residue at a constant weight.
Quality Control and Precautions
Instrument calibration: The thermogravimetric analyzer needs to undergo drift calibration every month, and the weighing balance needs to be verified daily with standard weights.
Environmental control: The laboratory temperature is maintained at 23 ± 2 ℃, and the relative humidity is 50 ± 5%.
Safe operation: Avoid direct contact with high-temperature equipment during the burning process, use heat-resistant gloves and goggles. The sulfuric acid treatment method needs to be operated in a fume hood to prevent the inhalation of acid mist.
This technology is widely used for quality control of polymer materials such as plastics and rubber, and evaluates the proportion of fillers and material properties through ash content assessment.