Piston performance testing mainly covers three key indicator tests:
1. Slippage Test: Using a dedicated testing instrument to simulate the actual injection process, the starting force and continuous movement force of the piston are measured. Typical standards specify an starting force ≤ 5N and a continuous force fluctuation ≤ 1.5N. This test effectively avoids dosage deviations or air bubble problems caused by abnormal force values.
2. Thrust Test: Using a piston thrust tester, constant speed, peak force, or uniformity tests are performed to quantify the force required to push the piston. An appropriate thrust range ensures patient comfort and avoids damage to the syringe structure.
3. Sealing Test: The sealing performance between the piston and container is verified through the negative pressure holding method (maintaining no leakage for 30 seconds at a specified pressure) or the air pressure monitoring method (detecting the pressure drop change after insertion into the cylinder). This test is particularly crucial for ensuring the stability of the drug solution during storage.
