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In order to test various properties of paint or other coatings it is necessary to create a consistent testable thickness. In order to achieve this goal the coating is spread evenly over a Drawdown card using a film applicator. This applicator can be operated by hand or automatically. When using an applicator manually small variations in speed and pressure applied are inevitable. These variations can affect the quality of the drawdown and thus the measurements of film properties such as abrasion resistance, hiding power and gloss. The use of an automatic film applicator guarantees consistent speed and pressure, providing repeatable and high quality results. Automatic film applicators vary in their construction. The most modern types of applicators use vacuum plates to hold the drawdown cards and allow a variety of application bars to be mounted. The speed and pressure of the bar can be adjusted to allow for customization of the final film thickness The drawdown process is governed by ASTM standard D823.〔http://www.astm.org/Standards/D823.htm〕 ==References== 〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Automatic film applicator」の詳細全文を読む スポンサード リンク
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