B31C1/086

CONVOLUTE CARDBOARD TUBE, APPARATUS AND METHOD FOR MANUFACTURING THE SAME
20230119158 · 2023-04-20 ·

A plastic film roll includes: a convolute cardboard tube including a tubular body having a tubular body wall formed by a plurality of layers of a straight rolled cardboard sheet having a weight equal to or less than 300 gsm; a plastic film wound about the convolute cardboard tube to form a plurality of plastic film windings around the convolute cardboard tube, the plastic film windings creating a radial compression force equal to or greater than 10 bar on the tubular body wall, wherein the cardboard sheet includes a plurality of fibers, at least a majority of the fibers being substantially aligned in a tangential direction relative to the tubular body to allow the convolute cardboard tube to resist the radial compression force.

Convolute cardboard tube, apparatus and method for manufacturing the same
11370628 · 2022-06-28 · ·

A plastic film roll includes: a convolute cardboard tube including a tubular body having a tubular body wall formed by a plurality of layers of a straight rolled cardboard sheet having a weight equal to or less than 300 gsm; a plastic film wound about the convolute cardboard tube to form a plurality of plastic film windings around the convolute cardboard tube, the plastic film windings creating a radial compression force equal to or greater than 10 bar on the tubular body wall, wherein the cardboard sheet includes a plurality of fibers, at least a majority of the fibers being substantially aligned in a tangential direction relative to the tubular body to allow the convolute cardboard tube to resist the radial compression force.