How to solve the problem of air residue in the syringe

It is not possible to produce plastic syringes without air bubbles, and some air molecules will remain in the syringe even at the lowest vacuum. If the best process conditions are used, the bubbles may be so small that they are not visible to the naked eye. The size of the remaining air bubbles mainly depends on the vacuum and filling level in the syringe during operation. The amount of dissolved gas is negligible, such as using a traditional vacuum.

veterinary syringe

Plugging method: Fill a 1ml (long) syringe with 0.75ml of water-based product and press the plug at a pressure of 100mbar, which will produce bubbles with a diameter of 2mm (based on the pressure of 1000mbar).

Because the gas is dissolved in the product, the volume of the bubbles can be reduced by about 10%. Generally, the pressure in the syringe must be significantly higher than the vapor pressure of the product. Low vacuum, small friction, high filling level, high gas solubility, and the use of a push rod all reduce the residual gas space in the syringe.