A suction cup is a device which has a shape like the half of a sphere, and it is used to adhere to surfaces without pores or holes (nonporous). The How Many Cups In 32 Oz is named so because of its ability to perform the process of suction. Often dubbed simply as a sucker, this device uses negative fluid pressure of water or air for adhering to nonporous surfaces. In addition, a rather fascinating aspect is that there are some animals like squid and octopus which utilize the same sucking principle.
When the center part of the cup is pressed against any surface which is devoid of pores, the volume of this space (between the flat surface and the suction cup) in the context is considerably reduced. And this causes the fluid to be expelled through the rim of the cup. Now when the user stops to apply any pressure further, the cup tends to get to its original shape.
The cup is made of elastic substances to assist the regaining of its original shape. The cavity now lacks pressure as the entire fluid has been forced out already. This makes a curious case, of low pressure cavity inside the cup and higher pressure on the outside of the cup and this pressure difference keeps the cup adhered to the nonporous surface in question.
On most occasions, suction cups aren’t used as a singular device but as attaching devices on other devices. These are used domestically to hold or hang small objects like signs, posters, calendars etc. on non-porous bigger objects like refrigerators, mats and even floors. Coming to the bigger commercial applications, the ‘fitting part’ of automobile windscreens (often for a temporary time frame) regularly utilizes suction cups.
Also, many toy darts and satellite devices use these cups. Still, one of the most common examples of suction cups is via the toilet plungers and shampoo holders. These are often called suction cup holders. If the suction cup is used to hang heavy objects or in places there is a lot of humidity (or even temperature variations) the grip will loosen and later it may deteriorate.
In many ways, the performance of a this cup depends on how clean is the surface of the cup. With due course of time, the performance hinders. The best way is to clean these cups thoroughly with warm water (even soapy water is fine) and be wiped with a dry cloth or left to dry. The performance would show an increase and if it doesn’t, then it’s time to invest in a new one.