Helaste

Helaste is a term that refers to a specific type of glass processing technique. It is a Finnish word that translates loosely to "frosting" or "etching" of glass. This process involves creating a matte or frosted surface on glass by chemically or mechanically altering its smoothness.

Chemically, helaste is often achieved using hydrofluoric acid. The acid reacts with the silica in the glass, creating a cloudy, opaque layer on the surface. Mechanically, sandblasting or abrasive grit can be used to create a similar frosted effect. The degree of frosting can be controlled by the duration and intensity of the treatment.

Helaste is employed for a variety of purposes in glass manufacturing. It can be used for decorative applications, such as creating patterns or textures on windows, mirrors, or glassware. It also serves functional purposes, such as reducing glare on screens or providing grip on handles. In some instances, helaste can also be used to obscure vision while still allowing light to pass through, making it useful for privacy applications. The technique is versatile and can be applied to various types of glass, including float glass and tempered glass.