摘要 |
A low-cost and effective coating composition for cardboard allows use of thinner paper board with the same or higher strength relative to conventional water-resistant cardboard. The resulting cardboard can also be repulped and more easily recycled. The inventive coating composition, preferably applied to the fluted inner ply of the cardboard (as a waterproof barrier), is compatible with the utilization of low-cost starch-based adhesives for gluing the fluting to the liners. At least one side of the fluting cardboard is coated with a composition comprising: from about 10% to 70% by weight, and more preferably from about 40% to 60% by weight, of sodium silicate; from about 10% to 60% by weight, and more preferably from about 30% to about 50% by weight, of a synthetic resin emulsion; from about 10% to 50% of a paraffin-water emulsion; and from about 5% to about 25% by weight of added water.
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