COLD-END COATINGS IN GLASS CONTAINER MANUFACTURE

In most modern manufacturing, bottles have become increasingly lighter in weight and speeds have accelerated enormously, both in the glass plant and on the customer's filling line. Because of these changes, the need for surface treatment is vital. Basically, the reason glass is cold-end coated is to protect and lubricate the ware so that it can be moved smoothly, without damage, with high-speed handling equipment from a massed group of bottles on the lehr into single lines for inspection. Cold-end coatings are usually applied over a hot-end coating of metal oxide which is applied before annealing. This combination of materials creates a so-called 'permanent' coating which cannot readily be washed off in water or deteriorate in storage.