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Phos-Prep, the modern solution for Pretreatment. |
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An Acid Etch and Degreaser for Aluminium used usually at ambient temperatures. immersion process. |
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The PHOS-PREP PP932 sulphuric acid based cleaner/etch has been specially formulated to remove scales and tarnish from aluminium to produce a chemically clean surface. Although PHOS-PREP PP932 contains an inbuilt surfactant system, it may be advisable to clean heavily oiled work in PP934 (an alkali immersion cleaner), followed by a rinse, prior to acid etching. Alternatively, additions of PHOS-PREP PP975 & PHOS-PREP PP976, surfactant additive’s, that may be added to the PHOS-PREP PP932 working bath. The etch rate from the PHOS-PREP PP932 treatment can be varied by adjustments to the immersion time, the bath temperature and bath concentrations. Acid resistant materials such as polypropylene, UPVC or polyethylene are preferred. The PHOS-PREP PP932 bath is normally operated at ambient temperature, at a concentration of 2% to 10% v/v with a process time of 2 to 10 minutes. For faster process times, or a deeper etched finish, the bath can be operated at stronger concentrations, elevated temperatures or longer process times. The optimum bath strength should be maintained to produce consistent results. Additions to the bath can be made on the basis of an assessment of the finish of standard of work, or by analysis of bath concentrations. Following treatment in the PHOS-PREP PP932 bath, the work should be adequately rinsed prior to further processing. LABORATORY CONTROL To a 20 ml bath sample add approximately 50 mls de-ionised water and 20 mls of 20% KF solution. Titrate the sample against 1M sodium hydroxide solution using phenolphthalein indicator to a pink end point. Titre = % vol / vol PHOS-PREP PP932 |
