A molecular sieve
A molecular sieve is a combination of silicon and aluminum oxides. Simply put, these are balls ranging in size from 0.5 to 2 mm with many pores that adsorb water vapor penetrating through the side seams of the double-glazed unit into the period of its operation.
The value of them is that these pores have a certain diameter. Water vapor molecules pass through them, but gas molecules do not pass through. Due to this ability to selectively absorb molecules, they were called the “molecular sieve”: they “screen out” water vapor from, say, argon, which is filled with the chambers of double-glazed windows for better thermal insulation.
The most important function of the molecular sieve is to reliably and as long as possible prevent moisture condensation in the space between the glasses caused by the penetration of water vapor into the package.
The absence of a molecular sieve will cause moisture to condense at a low temperature on the inner surface of the glass.
Therefore, we conclude that the molecular sieve is a very important part of a serviceable plastic window without defects!