These tips can help maximize the performance of your gluing equipment.
1. End seal leakage: Leakage sometimes results from over tightening, which can deform the backing plate. Also check to see that the roll ends clean and flush and if the sealing surface is flat.
2. Determining the glue spread rate: To determine the spread rate, cut a sample of stock exactly 1 square foot, then weigh it on a gram scale. Next, pass it through the machine and weigh again. Subtract the first weight from the second.
If the stock is coated on both sides, multiply the difference in weight by 1.1 for spread in pounds per thousand square feet. If only one side of the sample is coated, multiply by 2.2. (A wet film thickness gauge may be used to determine the spread rate on smooth coating applications, or as a comparison to above method.)
3. Changing the coating thickness: Increase the “doctor roll to coating roll” pressure for a thinner coating and decrease for a thicker coating. Also, roll groove patterns are designed to apply coats within certain thickness ranges, so consider changing to a different pattern.
4. Uneven coating: The rolls may not be parallel, or the substrate could be uneven. Prolonged running of smaller pieces also can cause uneven roll wear.
5. Glue pushed off the tail end of the board: There may be too much coating on the rollers, or the feed gap is too tight. Try raising the upper roll slightly (0.005).
Source: Black Bros. Co. For more information visit BlackBros.com, or call (800) 252-2568
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