In glass industry, waste rate of glass after cutting is very high, from 15 up to 45%. You may say that your off-cut can be reused, why you say the high waste rate? Ok, let’s talk about why. (tgm.net.nz copyrights reserved)
First of all, a normal stock sheet maximum sizes, depending on glass thickness, are from 2mm thickness, 1220 x1840; 3mm thickness, 2440mm x 3660; 4mm, 3210mm x 4500mm, 5-12mm thickness, 3210 x 5100. The thicker, the larger in a single pane as a stock sheet. However, due to transportation and container size limit, 3210mm x 5100mm are practically and usually the biggest in factory. We can see the normal glass shock sheet sizes in the market place are 2440mm x 3660mm and smaller. (tgm.net.nz copyrights reserved)
Secondly, why stock sheet in cage is cheaper, in single pane is dearer, and after cut to size, the smaller in size, the dearer in unit price? Well, in an unopened cage, there are more than 20-50 stock sheets in the cage, this is for whole sales. When work has been done to open the cage, split and crane a single stock sheet into rack, a lot of costs in labour, machinery and power occur, and sometimes the damage of a glass sheet during glass racking or processing occurs, resulting in the waste rate higher from time to time. Similarly, cut to size into smaller glass pane/sheet will be more work to do, and result in higher and higher waste rate and more off cuts in the rubbish bins.
Thirdly, all glass companies have limited storage rooms, for work efficacy, they have to throw a lot of off cuts into bins although we think they can be re-used. But in real production line and storage space, we are not able to stock too much of off cuts. Hence, glass stock sheets or cut to size glass panes are dearer as comparing to the original stock sheets or previous glass sheets, due to more work has been done and higher waste rate generated.
Fourthly, you should know that Cut-to-size or cut glass sheet smaller in size generates a lot of off-cuts, and waste management fees Auckland wide increases a lot recent years, and off-cuts of glass collection causes glass companies a lot of money, there is nothing free in glass industry.
At last, in most of the cases, when we repair a broken glass window or door, the broken glass pieces are collected by glaziers and then these shattered glass wastes are poured into bins, and the bin collection fees are hundreds or thousands per months, depending on your company scale and how many jobs you have done for your customers.