E.i. Dupont De Nemours and Company

Douglas Ray Stilwell

Robert Vincent Canning, Jr

Barry Rubin

Robert William Johnson

Thomas W Simpson, Iii

Robert V Canning

Scott Richard Mehr

Richard Walker Browne

Michael H Evans

Thomas William Iii Simpson

An automated computer-controlled method and apparatus for measuring the quality or fineness of a pigment dispersion sample, comprising placing the pigment dispersion at the deep end of the tapered path of a Hegman gage block, placing the Hegman gage block in a holder in a motorized drawdown device that draws the scraper along the length of the tapered path at an angle and to at a contact pressure and at a controlled rate, thereby creating a tapered film sample of paint whose thickness tapers from a maximum thickness of 100 micrometers to a minimum thickness of zero. An illuminator assembly illuminates the sample with a substantially collimated light source at an intensity level and the light reflected from the sample is collected by a lens onto a photodetector array in a digital camera. After a time interval the camera acquires an image of the sample. The image is digitized and stored in a memory in the computer and then a portion of the image within a region of interest corresponding to the sample in the tapered path is analyzed to detect and count pigment agglomerates that protrude above the surface of the sample.

Method and apparatus for quantifying pigment dispersion quality by paint drawdown

An image analysis method to quantify visual showthrough of printed images on the reverse face of planar objects, such as paper. An illumination level is set using a white reference object. A white reference image is stored in a computer memory. An image of a planar object having a printed image on the reverse face is stored in a computer memory. A pixel by pixel ratio of the two images is calculated and a mean value of the ratios is calculated to characterize the visual showthrough. The measurements are substantially independent of both the illumination level and image shading.

Method and apparatus for quantifying visual showthrough of printed images on the reverse of planar objects

Growing community of inventors

Wilmington, DE, United States of America

Douglas Ray Stilwell