WAX APPLIED DURING CURTAIN COATING OPERATION: D3708
EXPLANATION
Wax coatings are applied to corrugated board to provide a barrier against moisture or other penetrates or to provide improved appearance or abrasion resistance. These functional properties are influenced by the amount of wax present on the surface. During curtain coating operations, major portions of the wax will congeal on the surface, while a minor portion will penetrate and become embedded in the fibers of the facing. This method measures the total weight of wax applied to the board. The amount actually remaining on the surface of the corrugated board can be determined by Test Method D3521. The uniformity of wax application across the width of the curtain coater may also be determined using this technique by passing test combinations (blanks) under the curtain at various locations, that is, left side, right side. Related method for determining the weight of wax coating include Test Method D3521, D3522, and D3344.
TEST SUMMARY
A folded sheet of paper is attached to production corrugated board, the combination is run through the curtain coater, and subsequently the applied weight of the wax on the sheet of paper is determined.
TEST PRECISION
Repeatability is 10 % of the mean. No reproducibility data are available. This procedure has no bias because the value of weight of wax applied can be defined only in terms of this test method.
