I don’t have a frostruder myself, but have learned a few things from those who do. Aparently, one problem is that the frosting continues to extrude after there is no longer force being exerted on the plunger syringe. One idea is that there were air bubbles in the syringe from loading the frosting and the solution is to be better at packing.
I wanted to give it a try, so I removed the plunger from a syringe loaded it by vacuuming through the nozzle with a pump. The loading process went perfectly and there were no bubbles to speak of. I gave the plunger a push and out came some frosting. Success! Well, not really. After I stopped pressing the frosting continued to extrude. Why?
The frosting itself must be compressable! This makes sense since the frosting is a bunch of ingredients whipped and mixed together.
I then set up an experiment to observe the effects of air within the frosting in which one glob of frosting would be placed in an evacuated chamber while another would remain at 1 atmosphere of pressure (first image).
After the chamber was evacuated I could see that the test glob had expanded (second image), presumably from air within the frosting. The test glob collapsed as it was brought back to 1 atmosphere of pressure (third image).
I feel this supports the idea that air within frosting causes continued extrusion.
. A valve at the end on the frostruder to regulate frosting extrusion.
. Find an incompressable frosting-like material.
. Don’t use a plunger. Pump air behind the frosting and return it to 1 atmosphere when the frosting should stop extruding.
. Pull the plunger back to bring the pressure withing the syringe to 1 atmosphere.