Ultrasonics in lens cleaning - Part 1: Cleaning equipment and systems

摘要

Cleaning in some form or other plays an important part in the manufacturing of complete spectacles, lenses, frames and contact lenses and also of lens moulds and other equipment. This need to clean the products has become even more important with the introduction of organic lens materials, the majority of which will also require hard and anti-reflection coatings. This prerequisite of cleanliness is no more important than within the coating laboratory. All lens surfaces must be absolutely clean, otherwise the finished coating will not be mechanically stable. Although part of this cleaning process is completed during the coating cycle, by electrostatic discharge, the surface must still be pre-cleaned, to remove all but the most stubborn particles. Manual cleaning can achieve a reasonably acceptable result, but there is always the risk of mechanical damage to the surface and the process will be labour intensive and time consuming. The introduction of ultrasonic cleaners has led to much shorter cleaning times and a cleaner surface. This article is split into two sections. Part 1 deals with ultrasonic cleaning equipment and systems and Part 2 with water filtration and the various chemical compounds that are often used in the ultrasonic baths.