Plastic lotion pumps, one of the most popular dispensing methods for viscous (thick liquid) products in the personal care and beauty industry, come in all shapes and sizes. Many of these parts are Plastic Injection Molded! When used as designed, pumps dispense the right amount of product time after time. But have you ever wondered what goes in a lotion pump to makes it work? While there are hundreds of different designs in the market today, the basic principle is the same. Here is an overview of these components, and how they contribute to the overall functionality of pumping the product from the bottle to your hand.
Generally speaking, a lotion pump consists of the following components :
Actuator: An actuator, or the pump head, is what the consumer presses down to pump the product out of the container. The actuator is often made of Polypropylene plastic and can have many different designs – and often come with a up-lock or down-lock features to prevent accidental output,. This is one of the component designs that can set one pump apart from another when it comes to the exterior design, it is also the part where ergonomics play a role in consumer satisfaction.
Closure: The component that screws the entire assembly onto the neck finish of the bottle. It is identified with the common neck finish destination such as 28-410, 33-400. Often made of Polypropylene plastic, it is often designed with a rib side or smooth side surface. In certain cases a shiny metal over-shell can be installed to give the lotion pump a high-end, elegant look.
Outer Gasket: The gasket is often friction fitted to the inside of the closure and it acts as a gasket barrier on the bottle land area to prevent product leakage. This outer gasket can be made from a wide variety of materials depending on the manufacturer’s design : Rubber, LDPE are just two of the many possible options.
Housing: Sometimes referred to the pump assembly housing, this component holds all the pump components in place as well as acting as a transfer chamber that sends the product from the dip tube to the actuator, and ultimately to the user’s hand. This component is often made of Polypropylene plastic. Depending on the lotion pump output and design, the size of this housing can differ greatly.
Stem / Piston / Spring / Ball (Interior components inside the housing): These are the parts that can vary based on the design of the lotion pump. Some may even have additional components that aid the product flow, and some designs may even have additional housing components that isolate the metal spring from the product pathway, these pumps are generally referred to have a “metal free pathway” feature, where the product will not come in contact with the metal spring – eliminating the potential compatibility problems with the metal spring.
Dip Tube: A long plastic tube made of Polypropylene plastic that extends the reach of the lotion pump to the bottom of the bottle. Depending on the bottle the pump is paired with, the dip tube length will differ. A properly cut dip tube will maximize product usage and prevent clogging.
How Does it Actually Work?
A lotion pump acts much like a air suction device that draws the product from the bottle to the consumer’s hand despite the law of gravity telling it do the opposite. When the consumer presses down on the actuator, the piston moves to compress the spring and the upward air pressure draws the ball upwards, along with the product inside, into the dip tube and subsequently the chamber.
As the user releases the actuator, the spring returns the piston and actuator into it’s up position, and the ball is returned to it’s resting position, sealing the chamber and preventing the liquid product from flowing back down into the bottle. This initial cycle is called “priming”. When the user presses down on the actuator again, the product that is already in the chamber will be drawn from the chamber, through the stem and actuator, and dispense out of the pump and onto the consumer’s hand. If the pump has a bigger chamber (common for high output pumps), it may require additional priming before the product will be dispensed through the actuator.
Lotion Pump Output
The output of a plastic lotion pump is often measured in cc (or ml). Commonly in the range of 0.5 to 4cc, with some larger pumps with bigger chambers and longer piston / spring components having output up to 8cc. Many manufacturers have multiple output options for each of their lotion pump offerings, giving the product marketer full control of dosage.
Original Post/Credit to http://www.oberk.com/packaging-crash-course/whats-inside-a-lotion-pump