Kalamazoo, MI-based Western Michigan University's pilot paper-coating line now lets paper, paperboard and converting professionals industries have access to a new impregnator. The line can be used to study how the addition of water-based solutions can enhance the performance of paper and paperboard packaging.

In contrast to a size-press or calender-box, where only a 5-10 percent level of penetration can be obtained, the new impregnator allows materials to be forced into the sheet at penetration rates of up to 80 percent, on one side only. The impregnator will be of interest to papermakers, converters and suppliers looking to enhance strength and/or barrier properties in their products. Impregnators are typically used in converting operations where value-added specialized product performance properties are desired.

How it works: To impregnate the sheet, a water-based material is put under pressure—10-100 psi (0.7-7 bar)—which forces it into the sheet as the sheet passes through the treating shoe or nip. Depth of sheet penetration is controlled by liquid pressure and operating speed. WMU's impregnator is web-fed from a maximum 15-in. wide and 30-in. diameter roll.