Chemical glass frosting processes are widely used to create visual attractive glass surfaces. A commonly used frosting bath mainly contains ammonium bifluoride (NH₄HF₂) mixed with hydrochloric acid (HCl). The frosting process consists of several baths. Firstly, the preliminary bath to clean the object. Secondly, the frosting bath which etches the rough light scattering structure into the glass surface. Finally, the washing baths to clean the frosted object. This is where the constituents of the preceding steps accumulate and have to be filtered from the sewage. In the present contribution, phosphoric acid (H₃PO₄) was used as a substitute for HCl to reduce the amount of ammonium (NH₄⁺) and chloride (Cl⁻) dissolved in the waste water. In combination with magnesium carbonate (MgCO₃), it allows the precipitation of ammonium within the sewage as ammonium magnesium phosphate (MgNH₄PO₄). However, a trivial replacement of HCl by H₃PO₄ within the frosting process causes extensive frosting errors, such as inhomogeneous size distributions of the structures or domains that are not fully covered by these structures. By modifying the preliminary bath composition, it was possible to improve the frosting result considerably. To determine the optimal composition of the preliminary bath, a semi-automatic evaluation method has been developed. This method renders the objective comparison of the resulting surface quality possible.

中文翻译：

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磷酸钠钙硅酸盐玻璃磨砂工艺优化及半自动评价

化学玻璃磨砂工艺广泛用于制造具有视觉吸引力的玻璃表面。常用的结霜浴主要含有与盐酸（HCl）混合的氟化氢铵（NH ₄ HF _{2 ）。}结霜过程包括几个浴。首先，对物体进行初步清洗。其次，磨砂浴将粗糙的光散射结构蚀刻到玻璃表面。最后，用洗涤槽清洗磨砂物体。这是前面步骤的成分积累的地方，必须从污水中过滤掉。在目前的贡献中，磷酸 (H ₃ PO ₄ ) 被用作 HCl 的替代品，以减少铵 (NH ₄ ⁺) 和氯化物 (Cl ^- ) 溶解在废水中。与碳酸镁 (MgCO ₃ ) 结合使用时，它允许铵在污水中沉淀为磷酸铵镁 (MgNH ₄ PO ₄ )。然而，用 H ₃ PO _{4简单地替代 HCl}在结霜过程中会导致广泛的结霜误差，例如结构的不均匀尺寸分布或未被这些结构完全覆盖的区域。通过修改初步浴成分，可以显着改善结霜效果。为了确定初步浴的最佳成分，开发了一种半自动评估方法。这种方法使得对最终表面质量的客观比较成为可能。