This data was collected from a wide-ribbon float glass manufacturing facility with an excellent layout for internal handling of raw materials and glass. This facility features a well-designed, state-of-the-art production line with a furnace pull of 800 tons per day and a good energy consumption for the melting furnace (1530 Kcal/Kg glass melt).
Data collected over a course of year while the plant was only three years in operations; just to paint the full picture the production line—and particularly the furnace—were in optimum conduction; also, operators were skilled enough to optimize parameters. The glass handling processes, both inside and outside the factory, were specifically tailored for flat glass. Raw water was sourced from drilled wells at a depth of 125 meters, with high salinity. It was treated using the reverse osmosis (RO) process, which produced 48% soft water for the closed-loop circulating water system, 37% partially treated soft water for the open circulating water loop and batching, and 15% highly saline waste, the disposal of which posed a significant challenge.
Table 1 outlines the losses that occur at each stage of the float glass production, encompassing the entire journey from the introduction of raw materials into the furnace to the final stage of framing the glass in a window for the end user. The main contributing factors for these losses have been identified and quantified at each stage of the process.
Table 1 – Losses and Contributing Factors at Each Stage of the Float Glass Production Loop
| Stage | Total Loss, % | Factors Contributing to Loss at Each Stage | |||||||
| Production Line Loss (%) | 22.7 | Edge Loss | Melt Defects | Thickness Issue | Poor Annealing | Cutting & Stacking | Thickness Change | Warehouse Handling | Loading Breakage |
| 9.6 | 5.3 | 2.4 | 1.2 | 1.9 | 0.4 | 1.6 | 0.3 | ||
| Transportation Loss (%) | 4.1 | Glass Quality | packing | Driving | Road & vehicle | Unloading, Loading | |||
| 2.1 | 1.4 | 0.3 | 0.2 | 0.1 | |||||
| Processing Loss (%) | 19.4 | Cutting | Edging & Drilling | Printing & Decorating | Tempering & Soaking | Laminating | IGU Making | Handling | |
| 9.6 | 0.6 | 1.4 | 2.7 | 1.8 | 2.9 | 0.4 | |||
| Glazing Loss (%) | 3.4 | Cutting | Handling | ||||||
| 2.6 | 0.8 | ||||||||
| Total Loss (%) | 49.6 | ||||||||
As presented in Table 1, the majority of losses occur during the production of float glass and processed glass, accounting for approximately 42.1% of the total 49.6% loss percentage. This means that almost 85% of the losses during production are related to these stages, with the remainder primarily due to handling issues.
The takeaway here is clear: even in facilities operating under ideal conditions, waste is a persistent challenge. However, focusing on process optimization and eliminating avoidable waste offers a substantial opportunity for improvement. By minimizing production inefficiencies, optimizing material handling with the help of solutions such as LeanTechnique, and addressing preventable losses, manufacturers can significantly enhance yield and reduce waste. While some losses will always be part of the manufacturing process, the goal should be to make every effort to streamline operations and minimize those losses that can be controlled.