Method for compressing structured tissues
A method and apparatus are disclosed for processing structured tissue material to form a compressed bundle of folded tissues. A web of at least one ply of structured tissue is subjected to a destructuring operation before folding with itself or with another similar web to form a stack. The stack can then be compressed to form the compressed bundle at a pressure that is less than would have been the case, had the structured tissue not first been destructured.
1. A method of processing structured tissue material to form a compressed bundle of folded tissues, the method comprising:
providing a web comprising at least one ply of structured tissue;
at least partially destructuring the at least one ply of structured tissue;
folding the web with itself or with another similar web to form a stack;
compressing the stack at a compression of greater than 120 kN/m 2 to form a compressed bundle of folded tissues having a density of greater than 0.2 g/cm 3 ; and
wherein destructuring takes place by embossing and calendering the at least one ply of structured tissue, and wherein calendering takes place subsequent to embossing.
2. The method according to claim 1 , wherein embossing takes place at a pressure of from 15,000 N/mm 2 to 25,000 N/mm 2 .
3. The method according to claim 1 , wherein calendering takes place by setting a nip between calender rollers, wherein the nip is from 0.1 to 0.02 mm.
4. The method according to claim 1 , further comprising spreading the web subsequent to destructuring to remove wrinkles.
5. The method according to claim 1 , wherein the web has a weight of between 10 gsm and 65 gsm.
6. The method according to claim 1 , wherein the web comprises further plies of tissue material.
7. The method according to claim 1 , wherein the web is partially cut or perforated into sheets prior to being folded.
8. The method according to claim 1 , wherein the web is folded in an interleaved fold configuration.
9. The method according to claim 1 , wherein the stack has a width of between 70 mm and 100 mm.
10. The method according to claim 1 , wherein the stack has a length of between 1.5 m and 2.5 m.
11. The method according to claim 1 , wherein destructuring and folding take place in a tissue conversion machine in a continuous process and the stack is subsequently delivered to a compression station for compression of the stack.
12. The method according to claim 1 , further comprising delivering the compressed bundle to a bander station and wrapping the bundle in a wrapping web to form a wrapped bundle.
13. The method according to claim 12 , wherein the wrapped bundle is in the form of an elongated log and the method further comprises sawing the log into a plurality of individual tissue packages.
14. The method according to claim 1 , wherein the structured tissue is a three-dimensionally structured tissue paper web.
15. The method according to claim 1 , wherein the structured tissue material is a Through-Air-Dried material, an Uncreped-Through-Air-Dried material, an Advanced-Tissue-Molding-System material, a New Tissue Technology material, or a combination of any of these materials.