Single Use Syringe Testing
Plastic single use manual syringes require the evaluation of the force profile associated with expelling fluid from the syringe barrel. The most common tests are breakaway and glide force testing. Breakaway force measures the initial peak force required to begin plunger movement. Glide force is the average force required to continue depressing the plunger.
Syringe testing can be performed to the ISO 7886-1 standard. While there are several annexes in ISO 7886-1, Annex D and Annex E are most common for mechanical testing. Annex E specifies a test method for quantifying the forces needed to activate the syringe plunger. Annex D describes a test method for liquid leakage at the syringe piston under compression to ensure the closure system can withstand inadvertent over-pressurization. This test requires that the syringe be pre-filled, capped, and then tested axially under compression while a side load is applied to the plunger. After a 30 second force hold, the syringe must be checked for leaks.
The Instron® syringe test fixture allows users to determine both the breakaway and glide forces for syringes with a wide range of diameters. The fixture can also be used to perform needle cap pull-off tests.
ISO 7886-1 Annex G specifies a specific syringe fixture that includes a plunger holder, barrel holder, and reservoir table for holding a beaker. The Instron ISO 7886-1 compliant fixture is fully adjustable to accommodate multiple syringe sizes. To perform testing to Annex D, a side load is applied to the fixture by adding a simple, near friction-less sled fixture that includes a range of calibrated low force weights.