Hiding Power and paint Opacity characteristics are also affected by both film thickness and application method. Hiding Power is generally determined by the more expensive pigments such as anatase or rutile TiO 2, and CaCO 3 with high refractive indexes that scatter or bend light. Opacity(Y)=( Y black backing / Y white backing) x100 For paper, films, and other translucent solids, it is the ability of the sample itself to block the transmission of light.

Thus how well can a coating cover or obscure the preceding layer or substrate. For coatings, opacity is the hiding power, or ability to reduce the transmission of radiant energy or light, and/or increase the scattering of light, particularly in white. Opacity is defined as the ratio of light reflected when a sample is placed over a true white compared to a true black as a percentage. There is absolutely no need to use a much more expensive spectrophotometer to accomplish this easy task. The Novo-Shade-DUO+ was developed as a precise yet low cost inexpensive method to easily and accurately measure Opacity. Obviously this led to huge variations in observations. Traditionally opacity testing was performed using human vision by ASTM D344-11. Part Number - N008-026A Laboratory Drawdown Jr.Novo-Shade DUO+ Opacity Meter, Instantly Measure your ProductÃ¢¬¢s Opacity or your CoatingÃ¢¬¢s Hiding Power Part Number - N008-005 DRAWDOWN :BAR# SELECT ROD DIA either 1/4 inch, 1/2 inch or 3/8 inch >62: Standard Lab Rods with a Rod diameter of 1/4' is not recommended above 62 For example the number 3 rod would be 3 x 2.54 = 7.62 Microns.Ĩ2-90: Standard Lab Rods Only (Accu-Lab Jr. The number 20 rod would be 20 x 0.10 = 2.0 Mils.įor Microns, multiply rod number by 2.54. For example, the number 3 rod would be 3 x 0.10 = 0.30 Mils. To determine approximate wet film thickness in Mils for a specific rod number from the table below, multiply the rod number by 0.10. Standard Lab Rods (N008-056, N008-057 & N008-058) are less expensive due to a different manufacturing process and all of these are 16' long with a centred wound length of 12'. Part Number - N008-026A Laboratory Drawdown Jr. Part Number - N008-026 Laboratory Drawdown Jr. They are still called 'Mayer Bars' by many coaters. Wire-wound rods were first used in coating machines built by Charles Mayer in the 1900's to manufacture waxed paper and carbon paper. Although the technology goes back almost a century, today's high quality materials, multi-wire designs and special wire surfaces have made this system more popular than ever before. The market for wire-wound rods has grown rapidly during the past few decades, because they provide predictable, accurate coatings time after time, at a minimal cost. Rod selection tables allow coaters to consider coat weight and percent of solids in choosing the proper rod size for each production run.īottom-line profits have encouraged many coaters to modify existing machines, in order to take advantage of the flexibility, the ease of use and the dollar savings associated with rod coating. Wet coating thickness can be accurately predicted within one tenth of a mil (.0001'). These stainless steel rods are 4' shorter than conventional lab rods and offer an additional savings. Laboratory Drawdown Rods (N008-026, N008-026A) are designed for users producing test samples up to 8½' wide. With an overall length of 16', these rods are longer than the Jr. Drawdown Rods, Drawdown Bars, (also known as Mayer Bars)ĭrawdown rods give users the ability to fine-tune coating thickness quickly and easily, without altering the chemistry of their coating material, and without time-consuming and expensive changeovers.įor users that require a coating path of up to 12', use the standard Laboratory Drawdown Rods (N008-005 choose 1/4', 3/8', or 1/2').

Paint drawdown cards