Dry Ice is the term for carbon dioxide in a solid state. It is so-called because it does not melt into a liquid. Instead, it gradually reverts to its original gas form. This solid-to-gas transition is known as sublimation.
Dry Ice is extremely cold at -78.5oC. It is a non-toxic, colorless, odorless, and tasteless gas. Dry Ice is a readily available, economical, and versatile product to use. This makes it a valuable solution for a wide variety of industries.
How is dry ice made?
Dry ice is made by pressurising and cooling high purity carbon dioxide gas into a liquid form. The liquid CO2 is injected into a hydraulic press chamber where the atmospheric pressure converts it to a snow-like consistency. The CO2 snow is then compressed into solid blocks or pellets.
Any CO2 liquid that does not transform into snow is recovered in a CO2 gas form and recycled into the production process. The density of the compressed CO2 snow depends on the applied pressure and the pressure time. The density of a compressed block can reach 1.56g/cm3 as a maximum at a temperature of -78.64°C.
After being compressed into a solid state, Dry Ice will slowly revert to its original gas form. This gives the appearance of a steam or a fog emanating from it. CO2 gas has a greater density than air meaning it will concentrate on the ground. Caution should be exercised when storing Dry Ice in small enclosed spaces. The level of CO2 in the air can gradually build up and exceed safe levels.
How long does dry ice last?
10kgs stored in the small Polar Ice storage carton will last for up to 72 hours from the time you receive it. However, for best results, you should use the dry ice within 48 hours of receiving it. The more that you have stored in the container, the longer it will last. This means it’s important to have a delivery as close as possible to the time that you will use it.
Refrain from opening and closing the insulated container as much as possible. When you remove product from the container fill the empty space with wadded newspaper or styrofoam sheets. Any “dead-air-space” will increase the rate of sublimation.