Dunnage conversion machine, helically-crumpled dunnage product and method
A machine for converting a sheet stock material into a relatively less dense dunnage product includes both (a) a helical pre-form assembly having a cylindrical mandrel with a longitudinal axis and a guide member for guiding the sheet stock material from a supply thereof into a helical path along and around the mandrel so as to form a helical pre-form that rotates around the longitudinal axis and advances parallel to the longitudinal axis; and (b) a restriction in the path of the pre-form that slows the advance and rotation of the pre-form past the restriction, the restriction causing the pre-form to retard longitudinal advancement, to twist upon itself, and to permanently deform as it moves past the restriction, thereby longitudinally and helically crumpling the pre-form.
1. A dunnage product, comprising a sheet material having a longitudinal dimension wound along a helical path into a helical configuration with adjacent edge portions joined together to form a helical seam, the sheet material being permanently deformed with randomly-disposed helical and circumferential folds in the sheet material;
wherein the adjacent edge portions are joined together by an adhesive to form the helical seam.
2. The dunnage product of claim 1 , where the sheet material is paper.
3. The dunnage product of claim 2 , where the sheet material is kraft paper.
4. The dunnage product of claim 2 , where the sheet material has a basis weight of approximately 120 gsm.
5. The dunnage product of claim 1 , where the helical seam has a width of approximately 10 mm to 15 mm.
6. The dunnage product of claim 1 having a tubular shape.
7. The dunnage product of claim 1 having a generally circular cross-section.
8. The dunnage product of claim 7 , having a diameter of approximately 80 mm to 100 mm.
9. The dunnage product of claim 1 , where the sheet material has a width of approximately 90 mm to 150 mm.
10. A dunnage product produced by the process of:
helically winding a strip of sheet material around a mandrel along a helical path to form a helical pre-form;
advancing the pre-form in a direction parallel to a longitudinal axis of the mandrel; and
longitudinally and helically crumpling the helical pre-form to form a dunnage product having a sheet material in a helical configuration with adjacent edge portions joined together to form a helical seam, the sheet material being permanently deformed with randomly-disposed helical and circumferential folds in the sheet material.
11. The dunnage product produced by the process of claim 10 , where the winding step includes advancing a strip of sheet material along a helical path using a drive belt that extends around the mandrel.
12. The dunnage product produced by the process of claim 11 , where the crumpling step includes restricting the rate of advancement of the helical pre-form to cause the sheet material to crumple.
13. The dunnage product produced by the process of claim 11 , comprising the step of separating discrete sections of the crumpled sheet material after the crumpling step.