Stretch film and method for producing a stretch film
View Patent ↗A stretch film for the packing of goods, particularly for the packing of goods stacked on a pallet, comprises a prestretched main film ( 10 ). The main film ( 10 ) is reinforced by reinforcement strips ( 12 ) extending in the longitudinal direction. The reinforcement strips ( 12 ) are made from film strips of prestretched film which have been folded a plurality of times in the longitudinal direction. Between two adjacent reinforcement strips ( 12 ), the main film ( 10 ) can comprise two mutually staggered rows of holes ( 16,18 ). This stretch film with perforations ( 14 ) is particularly useful for the packing of food items.
1. A method of producing a stretch film for packing items, comprising:
supplying film strips from a first prestretched film,
folding the film strips at least once in a transverse direction thereof to obtain reinforcement strips,
supplying a prestretched main film, and
attaching the reinforcement strips to the main film in such a manner that the reinforcement strips extend in parallel to each other in a longitudinal direction of the main film,
wherein the main film and the reinforcement strips are adhered to each other while they have different temperatures; and
wherein, after the reinforcement strips are adhered to the main film, a plurality of mutually staggered rows of oval or elliptic holes are configured between two reinforcement strips to extend in the longitudinal direction of the main film so that the shorter semiaxis is oriented in parallel to the tension direction prevailing in the stretched film.
2. The method according to claim 1 , wherein the film strips are generated by cutting the first prestretched film.
3. The method according to claim 1 wherein at least one of the main film and the first prestretched film includes additives for intensifying a connection between the main film and the first prestretched film.
4. The method according to claim 1 wherein the main film and the reinforcement strips are attached by application of heat.
5. The method according to claim 1 wherein the film strips are folded two to four times.
6. The method according to claim 1 wherein at least three reinforcement strips are provided in parallel to each other.
7. A stretch film, comprising:
a prestretched main film;
reinforcement strips made from a prestretched film and extending in a longitudinal direction of the prestretched main film; and
a plurality of holes perforated in the main film only in regions between the reinforcement strips and having reinforced edges;
wherein the reinforcement strips are film strips made from the prestretched film which is folded in the transverse direction.
8. The stretch film according to claim 7 , wherein the holes are configured in mutually staggered rows.
9. The stretch film according to claim 7 , wherein the reinforcement strips comprise the film strips made from the prestretched film which is folded two to four times.
10. The stretch film according to claim 7 , wherein said reinforcement strips comprise at least three mutually parallel reinforcement strips.
11. A method of packing food items with the stretch film of claim 7 .
12. A method of wrapping a pallet load with the stretch film of claim 7 .
13. The stretch film according to claim 7 , wherein the holes are oval or elliptic holes each having a longer semiaxis oriented transversely to the longitudinal direction of the main film so that a shorter semiaxis of said hole is oriented in parallel to a tension direction prevailing in the stretch film.
14. A method of producing a stretch film for packing items, said method comprising:
supplying film strips from a first prestretched film,
folding the film strips at least once in a transverse direction thereof to obtain reinforcement strips,
supplying a prestretched main film other than the first prestretched film and the reinforcement strips,
adhering the reinforcement strips to the main film in such a manner that the reinforcement strips extend in parallel to each other in a longitudinal direction of the main film, and
perforating holes in the main film only in regions between the reinforcement strips.
15. The method according to claim 14 , wherein:
said perforating holes in the main film only in regions between the reinforcement strips is performed after the reinforcement strips are adhered to the main film.
16. The method according to claim 15 , wherein said perforating forms the holes in multiple rows elongated in the longitudinal direction of the main film, and the holes in adjacent said rows are mutually staggered.
17. The method according to claim 16 , wherein said holes are oval or elliptic holes each having a longer semiaxis oriented transversely to the longitudinal direction of the main film.
18. The method according to claim 17 , wherein the main film and the reinforcement strips are adhered to each other while they have different temperatures.
19. The method according to claim 14 , wherein said adhering comprises adhesively bonding or heat bonding.
20. The method according to claim 14 , wherein the film strips are generated by cutting the first prestretched film which is identical to the main film.
21. The method according to claim 14 , wherein the film strips are folded two to four times.
22. The method according to claim 14 , wherein at least three said reinforcement strips are adhered, in parallel to each other, to the main film.