Grades 3–5 · Machines
How does a trigger bottle turn liquid into a spray?
A spray bottle can turn one squeeze into many little drops. Inside its head, the trigger moves a piston in a small pump chamber. A long dip tube connects that chamber to liquid near the bottom of the bottle.
In the diagramThe nozzle turns a push into a sprayA primed trigger sprayer · enlarged flow-path cutawayDip tubePump chamberInlet shutOutlet openSqueeze: volume fallsDropletsLiquid breaks into drops at the nozzle; no gas is made.
Once the pump is full of liquid, squeezing makes its chamber smaller. The inlet valve closes against backward flow into the bottle. Pressure opens the outlet path and sends liquid toward the nozzle. The narrow, shaped passage makes the liquid emerge as a jet or sheet that breaks into droplets. Different nozzles give different spray patterns.
Releasing the trigger lets the spring return the piston. The chamber grows, its pressure falls, and liquid rises through the dip tube and inlet valve. The outlet valve stops reverse flow. A vent admits replacement air to the bottle. The next squeeze has another small dose ready. Your hand supplies the pumping energy; the spray is divided liquid, not a new gas.
About this explanation
Starting knowledge: Recognize liquid flow, bending and moving parts.
Sources
- Yuyao Rainbow Packaging — Trigger Spray Bottles: How They Work and Why They Fail