A lotion pump is an accessory used with cosmetic containers to dispense contents. It functions as a liquid dispenser that utilizes the principle of atmospheric equilibrium: pressing the pump forces the product out of the bottle while simultaneously allowing external air to enter and replace the displaced volume.
1. Working Principle
When the actuator is manually pressed downward, the volume of the spring chamber decreases and the pressure rises. Liquid flows through the valve core opening into the nozzle chamber and is then expelled through the nozzle. Upon releasing the actuator, the volume of the spring chamber increases, creating negative pressure; this causes the ball valve to open, allowing liquid from the bottle to flow into the spring chamber. At this stage, a certain amount of liquid is already held within the valve body. When the actuator is pressed again, the stored liquid is forced upward and expelled through the nozzle.
2. Performance Indicators
Key performance indicators for the pump include the number of strokes to prime (empty-press count), output volume, actuation force, actuator opening torque, rebound speed, and water intake metrics.
3. Difference Between Internal and External Springs
With an external spring design, the spring does not come into contact with the product contents, thereby eliminating the risk of contamination caused by spring rust.
Pump heads are widely used in the cosmetics industry across skincare, personal care, and fragrance sectors. Applications include products such as shampoos, body washes, body lotions, serums, sunscreens, BB creams, liquid foundations, facial cleansers, and hand soaps.