Date of Award

12-1997

Degree Name

Bachelor of Science

Department

Paper Science and Engineering

Abstract

Fluorescent office lighting has been shown to fade ink jet colors. Fading of ink jet dyes is a problem when the shelf life of documents is important. For effective, low cost ink jet printing, the color quality of the printed paper must be maintained for a duration of time. Research in hot melt adhesives has shown a reduction of color loss associated with the use of antioxidants.

During this thesis, a coating formulation was tested with and without an antioxidant present. The antioxidants tested were alpha tocopherol I vitamin E, and sodium thiosulfate. The addition rate was varied at 2.65 % and 5.17 % to determine which addition rate was required to produce the best color fastness.

Coated paper samples were printed with a color test pattern utilizing the primary colors: red, yellow, blue and black .. The paper samples, printed with the test pattern, were analyzed with the brightimeter to determine their initial color values (L, a, b) and brightness.

The samples were aged using an accelerated aging device, the fade-ometer, to test the ability of the antioxidants to resist fading under fluorescence. It has been determined that the duration of 12 hours of 500 W/m2 is equivalent to one month of sunlight in Michigan in the month of June. The fade-ometer times were chosen to be 12, 24 and 36 hours of exposure representative of 1, 2 and 3 months of normal exposure. The L, a, b values of the samples were measured after each aging period. To determine the ability of the antioxidant to reduce color loss, all brightimeter values of each antioxidant coating were compared against all brightimeter values of the non-antioxidant coating.

Both the basesheet and the coated sheets, after aging, were tested for brightness, and color difference (L, a, and b ). The results were compared to determine the surface effects of the coating on the substrate during time. Also, the results were compared to determine which antioxidant level minimizes color loss.

The importance of this project was to determine the extent of color loss that is prevented by the use of antioxidants. Color ink jet printing must have the ability to resist color loss for a duration of time.

Color fastness of the paper is important and should be maintained for a duration of time. Improved color fastness was shown to exist in paper samples coated with a low level of antioxidant. Both antioxidants, vitamin E and sodium thiosulfate, decreased the color loss associated with accelerated aging conditions in the fade-ometer.

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