초록 ▼

Paper and paperboard which have been thoroughly dried but not calendered is provided with a smooth surface by rewetting a thin layer (5% to 10% of the thickness) along the surface and then pressing the resulting damp surface against a substantial portion of the surface of a heated dryer drum or othe

Paper and paperboard which have been thoroughly dried but not calendered is provided with a smooth surface by rewetting a thin layer (5% to 10% of the thickness) along the surface and then pressing the resulting damp surface against a substantial portion of the surface of a heated dryer drum or other smooth-surfaced cylinder. This technique provides the web with a surface comparable in smoothness with what can be obtained by calendering but without the degree of compaction which occurs in calendering, due to the fact that with the major portion of the web dried, it is highly resistant to such compaction. The same method steps can be applied subsequently to the reverse side of the web to provide it with two smooth surfaces. It is also possible to forego the rewetting step if the initial drying of the web is unsymmetrical so that one surface remains wetter than the remaining portion of the web.

대표청구항 ▼

The method of producing a smooth surface on a web of paper or paperboard while minimizing the compaction thereof which comprises the steps of: (a) providing an unfinished web of paper or paperboard having a solids content in the range of at least substantially 80% throughout the major portion of the

The method of producing a smooth surface on a web of paper or paperboard while minimizing the compaction thereof which comprises the steps of: (a) providing an unfinished web of paper or paperboard having a solids content in the range of at least substantially 80% throughout the major portion of the thickness thereof measured from one surface thereof but having a lower solids content in the range of substantially 50% to 70% in a layer including the other surface thereof and constituting not more than substantially 5% to 10% of the thickness thereof, (b) guiding said web into partially wrapping relation with a heated cylinder with said lower solids content surface in contact with said cylinder, and (c) pressing said web into intimately contacting relation with said cylinder over the entire wrapped portion thereof.