The oxygen bomb aging tester is used to simulate the oxygen high-pressure environment, assess the anti-aging performance of rubber, plastic and other materials, and verify the life and stability of materials under the high-temperature and high-pressure oxygen atmosphere. The following is the standard use method:
Environment and equipment inspection: The test environment temperature is controlled between 15 ℃~35 ℃, and the relative humidity is ≤ 75%. Check the sealing of the equipment (oxygen bomb chamber, pipeline interface) to ensure no air leakage; Confirm that the temperature control system, pressure sensor, and safety valve are functioning properly.
Sample preparation: Cut 3-5 standard size samples (usually dumbbell shaped or sheet shaped, with dimensions specified according to material standards), with no scratches or impurities on the surface of the samples. After drying to a constant weight, record the initial state (appearance, size, hardness, etc.).
Instrument calibration: Calibrate pressure sensors (error ≤± 0.1MPa) and temperature controllers (error ≤± 1 ℃) to ensure accurate test parameters.
Auxiliary preparation: Prepare oxygen with a purity of ≥ 99.5% and check that the oxygen cylinder pressure is sufficient; Prepare tweezers, sample fixtures, record forms, and other tools.
Clamp the sample: Fix the sample evenly on the sample holder inside the oxygen bomb chamber, without contact between the samples, to avoid mutual influence.
Sealed oxygen bomb: Close the oxygen bomb chamber, ensure that the sealing gasket is installed in place, and tighten it evenly with bolts to prevent high-pressure air leakage.
Oxygenation and warming up:
Slowly inject oxygen into the oxygen bomb, adjust the pressure to the test set value (conventional 0.5-3MPa, adjusted according to material requirements), hold the pressure for 5 minutes, and check for air leakage.
Set the test temperature (conventional 70 ℃~150 ℃) and insulation time (24~1000h), start the equipment heating program, and ensure that the temperature rises uniformly to the target value.
Constant temperature aging: Timing starts after the temperature reaches the set value, during which the oxygen bomb pressure and temperature are monitored in real time. If the pressure drops by more than 0.05 MPa, it needs to be pressurized to the set value and recorded.
Cooling and pressure relief: After reaching the set aging time, turn off the heating system and let it cool naturally to room temperature. Slowly open the pressure relief valve and reduce the pressure inside the oxygen bomb to atmospheric pressure (pressure relief rate ≤ 0.1MPa/min, to avoid impacting the sample).
Remove the sample: Open the oxygen bomb chamber, use tweezers to remove the sample, and place it in the testing environment for 24 hours.
Performance testing: Compare the appearance (cracking, discoloration, and sticking), size change rate, tensile strength retention rate, hardness change, and other indicators of the sample before and after aging.
Result judgment: If all performance indicators meet the material technical requirements (such as tensile strength retention rate ≥ 70%, no obvious cracking, etc.), it is judged as qualified; If the performance degradation exceeds the standard, it is necessary to analyze the material formula or adaptability to the usage environment.
High pressure operation requires wearing protective gloves and goggles. It is strictly prohibited to open the chamber before the oxygen bomb is depressurized to prevent oxygen shock or sample splashing from injuring people.
Oxygen is the combustion supporting gas, and open flames, flammable and explosive materials are prohibited around the equipment. Regularly check whether the pipeline is aging and leaking.
After the experiment is completed, clean the oxygen bomb chamber and sample holder, and store them dry; Regularly verify safety valves and pressure sensors to ensure equipment safety and reliability.