A soap dispenser (in Europe mostly known as a soap squirter) is a device that, when manipulated or triggered appropriately, dispenses

soap Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are use ...

(usually in small, single-use quantities). It can be manually operated using a

handle A handle is a part of, or attachment to, an object that allows it to be grasped and manipulated by hand. The design of each type of handle involves substantial ergonomic issues, even where these are dealt with intuitively or by following tra ...

or can be automatic. Soap dispensers are often found in

public toilet A public toilet, restroom, public bathroom or washroom is a room or small building with toilets (or urinals) and sinks for use by the general public. The facilities are available to customers, travelers, employees of a business, school pupils ...

Design

Manual soap dispensers

The design of a manual soap dispenser is generally determined by whether the soap comes in liquid, powder, or foam form.

Liquid soap

When soap is dispensed in liquid form, it is generally in a

squeeze bottle A squeeze bottle is a type of container such as a plastic bottle for dispensing a fluid, that is powered by squeezing the container by exerting pressure with the user's hand. Its fundamental characteristic is that manual pressure applied to a r ...

pump A pump is a device that moves fluids (liquids or gases), or sometimes slurries, by mechanical action, typically converted from electrical energy into hydraulic energy. Pumps can be classified into three major groups according to the method they u ...

. The most popular soap dispensers of this type are plastic pump bottles, many of which are

disposable A disposable (also called disposable product) is a product designed for a single use after which it is recycled or is disposed as solid waste. The term is also sometimes used for products that may last several months (e.g. disposable air filter ...

. William Quick patented

liquid soap Soap is a salt of a fatty acid used in a variety of cleansing and lubricating products. In a domestic setting, soaps are surfactants usually used for washing, bathing, and other types of housekeeping. In industrial settings, soaps are used a ...

on August 22, 1865. Minnetonka Corporation introduced the first modern liquid soap and cornered the market by buying up the entire supply of the plastic pumps needed for the liquid soap dispensers.

= Parts of the liquid soap dispenser

= •Actuator- This is the top of the pump from which is pressed down to get the liquid out •Closure- Closure is the bottle that is fastened to the bottle's neck. it has a smooth or ribbed surface •Outer gasket- Made up of plastic or rubber, it is fit inside the closure and prevents leakage •Housing- The main pump that keeps the other components in the right place and sends liquid to the actuator from the dip tube •Dip tube- This is the visible tube that carries liquid from the bottom of the bottle up to the housing •Interior components- There is a variety of components including a spring, ball,

piston A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tig ...

, and/or stem that help moves the liquid to the actuator

= How does the liquid soap dispenser work?

= The handwash bottle acts much like an air suction device that draws liquid upwards to the user’s hands against the force of

gravity In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...

. When the user presses down the actuator, the piston compresses the spring and upward air pressure pulls the ball upward, along with the liquid product into the dip tube and then reaches the housing. When the user releases the actuator, the spring returns the piston and actuator to the normal position and the ball returns to its earlier position to stop the backflow of the liquid back to the bottle. This process is called ‘priming' and is only used when the handwash is put in the bottle. When the user presses the bottle again, the liquid in the housing is drawn from there and is released out of the actuator. During this process, the housing is again filled up with the handwash from the bottle, and the process goes on.

Dry soap

Some soap dispensers take solid bars of soap, and grate, plane, or grind them to flakes or powder as they are dispensed. About fresh weight of soap is equivalent to of liquid soap, providing soap for up to 400 handwashings. Soap mills are common in public washrooms in Germany. Soap graters made specifically for home use also exist; they can be wall-mounted, or free-standing (like a pepper grinder) and waterproof for use in a shower. Some graters take specially-dimensioned soap bars, others will take a range of ordinary soap bar sizes. Dispensers of pre-powdered soaps, such as

borax Borax is a salt (ionic compound), a hydrated borate of sodium, with chemical formula often written . It is a colorless crystalline solid, that dissolves in water to make a basic solution. It is commonly available in powder or granular form, ...

, often take the form of a metal box with a weighted lever; when the lever is pressed, a handful of soap is released. Ground soap is also used to wash laundry.

Foam soap

Foam soap dispensers have dual

foam pump A foam pump, or squeeze foamer and dispensing device is a non- aerosol way of dispensing liquid materials. The foam pump outputs the liquid in the form of foam and it is operated by squeezing. The parts of the foam pump, mostly made from polypro ...

s that when used, move both air and soap, injecting both together through small openings to create a lather. They can be found in both manual and automatic varieties. Manual dispensers of foam soap often consist of a large

button A button is a fastener that joins two pieces of fabric together by slipping through a loop or by sliding through a buttonhole. In modern clothing and fashion design, buttons are commonly made of plastic but also may be made of metal, wood, ...

that squeezes the foam out of a tube. Many liquid soap dispensers operate in this way as well. A few dispensers operate with a lever that pulls forward and squeezes the soap out. The majority of manual foam soap dispensers have the soap in a bladder in the dispenser in liquid form, as the pump is pressed the liquid soap is pushed through a small foaming nozzle which foams the soap.

Automatic soap dispensers

An automatic soap dispenser is specifically a hands-free dispenser of

(both liquid soap and foaming soap), but generally can be used for other liquids such as

hand sanitizer Hand sanitizer (also known as hand antiseptic, hand disinfectant, hand rub, or handrub) is a liquid, gel or foam generally used to kill many viruses/bacteria/microorganisms on the hands. In most settings, hand washing with soap and water is ge ...

shampoo Shampoo () is a hair care product, typically in the form of a viscous liquid, that is used for cleaning hair. Less commonly, shampoo is available in solid bar format. Shampoo is used by applying it to wet hair, massaging the product into the ...

s, or hand lotions. Automatic dispensers are often

battery-powered An electric battery is a source of electric power consisting of one or more electrochemical cells with external connections for powering electrical devices. When a battery is supplying power, its positive terminal is the cathode and its negat ...

-powered. Hands-free dispensers for water and soap/hand sanitizer have particular virtues for operating theatres and treatment rooms.

Mechanism

The touch-free design dispenses the liquid when a sensor detects motion under the nozzle. The electronic components of an automatic soap dispenser allow for a timing device or signal (sound, lights, etc.) which can indicate to the user whether they have washed their hands for the correct amount of time or not.

References

{{commonscat, Soap dispensers Kitchenware Bathroom equipment Toilets Soaps Dispensers