Waste glass as an eco-friendly secondary raw material is of central importance in glass production. For the glass factories the cullet must meet high quality requirements. A high level of purity is necessary for optimal recycling. Colour sorting is of equal importance as the removal of contaminants (ceramics, stones, porcelain, metal, etc.) and the separation by glass types (flat glass, hollow glass, special glass such as monitor glass or lead glass, etc.).

In flat glass recycling both product-related contaminants (e.g. heating wires and foils in car windows) and any other contaminant materials (ceramics, stones, porcelain, building rubble, metals, putty, plastics, heat-resistant glass, glass-ceramics, etc.) must be sorted out. Recycled flat glass primarily is processed into construction glass and car glass and must meet high quality requirements.

Hollow glass recycling saves considerable amounts of raw materials (quartz sand, soda, limestone, dolomite, etc.) and energy, and helps avoid CO2 emissions. Efficient recycling processes require the use of sorting (colour) and separating (contaminants) systems, because only these allow the production of new glass containers and bottles in perfect quality.

The sorting of special glass types (monitors, fluorescent lamps, etc.) is a decisive prerequisite for high-quality recycling and for the completion of material cycles. Sesotec sorting and separating systems, which for example separate lead-free front glass from leaded cone glass, allow a high-quality, environmentally compatible, and economically efficient recycling of special glass.