Tissue Technology

By Nick Mike, NGM Tissue Consulting, LLC

SUBJECT: A three point stickies control strategy

PROBLEM: Stickies on machine surfaces and components

DISCUSSION: Some stickie issues are from single source contamination such as asphalt or tape residue. This is best combated with a dispersant control program. However, most secondary fiber sources utilizing MOW or SOW encounter a variety of 5 or more types of stickies. The approach to controlling these multi contaminants differs from single source issues.

Most stickies will somehow come to the machine no matter how efficient the fiber treatment mill is. Stickies can be colloidal sized and pass through with the water loop. They can deform and pass through screens or grow to a troublesome size by cycling in the system. The best approach to controlling multisource stickies is to assume the stickies will be carried to the machine and attack these contaminants there. This is best accomplished utilizing a three point program.

1. DISPERSION utilizing mechanical, thermal or chemical energy is first. By getting the stickies small enough to pass through with the sheet, an exit for the stickies is available. Keeping stickies small also prevents mechanical entanglement with felts and wires.

2. PASSIFY the stickies using charge control. By surrounding the stickies with a charge that prevents them from re agglomerating or adhering to machine component surfaces, they will not enlarge and will pass through with the sheet in a size almost at the colloidal level.

3. PROTECT the machine components from stray stickies or collected break offs with a barrier protection on the wire. Felt and roll barriers are also effective if needed. Sometimes a problematic face side roll can be treated at the nip of a wire or felt by applying the passivation component into the nip. This protects both the roll and wire (or felt), and reduces pacifier cost. .

The result of this three point stickies control program results in removal of the stickies with the sheet and reduced stickie issues from whatever the deink plant sends to the machine.

Nick Mike of NGM Tissue Consulting, LLC can be reached by calling 603-616-8931, or by email at nmike03580@yahoo.com.