DUBIEL VITRUM SP. Z O.O.

Thermally strengthened glass, also known as semi-tempered glass, is commonly used in construction. Similar to tempered ESG glass, it offers greater mechanical and thermal resistance compared to annealed float glass, albeit with lower strength than fully tempered ESG glass. A distinguishing feature is its characteristic crack pattern upon breakage: the glass breaks into larger pieces that radiate toward the edges, preventing the pane from falling out of the frame. In contrast, tempered glass shatters into small, blunt fragments. Thermally strengthened glass is denoted by the abbreviation TVG (from the German *Teilvorgespanntes Glas*). Thermal strengthening is a process similar to tempering but involves a slower cooling intensity. Air cooling induces compressive stresses, enhancing the glass's strength. The internal stresses generated during this process are relatively lower than those in tempered glass. Thermally strengthened glass ("semi-tempered") produced by Dubiel Vitrum is marked with a permanent CE symbol, confirming compliance with the PN-EN 1863 standard.

Toughened glass is safety glass. It is denoted by the acronym ESG (from German, Einscheiben Sicherheitsglas). It features higher elasticity, mechanical, and thermal strength compared to annealed float glass; it is safer because when broken, it shatters into small, non-sharp fragments. Tempering glass involves heating it to a high temperature (620-680°C) and rapidly cooling it in a stream of compressed air. This process creates compressive stress in the surface layer, significantly increasing the glass's strength. At Dubiel Vitrum, the tempering process produces: Flat toughened ESG glass Bent glass with cylindrical shapes (safe ESG glass) Thermally strengthened TVG glass (so-called semi-toughened) Flat toughened ESG glass painted with cured ceramic paints (enamel paints applied to the entire surface or via screen printing).