| 摘要 |
Soiled hot end coated glassware having a substantially colorless and transparent thin protective coating thereon including an organic coating material is washed in an inhibited aqueous caustic soda cleaning solution to inhibit the deleterious effects of repeated washings and thereby increase the effective life of the protective coating. The cleaning solution comprises on a weight basis from 0.3 percent to 6 percent of caustic soda, from 0.01 percent to 0.3 percent of at least one soluble zinc containing compound when calculated as zinc oxide, and the remainder water. Other ingredients which may be present include from 0.002 percent to 0.05 percent of a synthetic organic phosphate ester anionic surfactant having hydrotrophic properties, from 0.001 percent to 0.03 percent of a low foaming synthetic alkoxylated nonionic surfactant, and from 0.008 percent to 0.2 percent of a hard water conditioning sequesterant. The protective coating preferably comprises polyethylene, and for best results a metal oxide layer is applied to the surface of the glassware while hot and a layer of the organic coating material is applied thereover and bonded thereto. A novel inhibited caustic soda cleaning solution having the above composition is provided, and also a liquid additive composition which is useful in preparing the cleaning solution and maintaining the ingredients thereof at proper concentrations. The desirable properties of the hot end coated glassware such as improved lubricity and increased strength are preserved and unsightly discoloration is prevented. |
