historia szkła
The first glass centers were created probably in
Babylonia and Egypt around 3000 B.C. In ancient times, a glass production boom
was related with the setting up of glass factories in Italy and on Murano
island which consists of five islands in the Venetian Lagoon. It was there that
mirror production first began. In Poland, the first glass products were
invented around the turn of X/ XI century.
The glass industry all over the world started to
develop very quickly in the XX century. In those days, the first machine for
the automatic production of glass packaging was created.
In Poland those product were produced mainly in
the glass factories of Sandomierz,
Piotrkowo Trybunalskie, Krosno, Wałbrzych, and Szklarska Poręba.
Glass formation
Glass is created though a fusion of quartz sand with soda, limestone, sometimes also with potassium and borax, fining agents, and bleaching substances or colorants. After melting from mixture, the formed product is left to cool down.
The natural glass has a green colour caused by the iron oxide (contamination of the sand, FeO). To obtain a colorless glass, you should add some oxidants to the sand (for example arsenic or sodium nitrate) and connections which have completive (dopełniający) colour. To obtain a glass which has special properties, you should use suitable additives, for example to obtain so-called “crystal” glass you should add lead compounds to normal glass (związek ołowiu), to obtain heat resistant glass you should use aluminium compounds (związki glinu).
Production
of the flat glass
- Loading sand, limestone,
and anhydrous soda
(a) to the stove
(b) The layer of melted glass congeals
(zastygać ) on the melted tin (cyna) surface
(c) after refrigeration
(d) Further
refrigeration on rollers
(e) cutting the glass by a chisel
(f)