Packaging roll films and preparation methods thereof are provided. A first transparent adhesive tape layer may be capable of covering a second high-adhesion layer such that the problem caused by the exposed second high-adhesion layer may be solved. The adhesive film and the non-adhesive film may not need to completely cover the second high-adhesion layer during the process. When the roll film is unrolled for packaging an item, the rolling drum may stop rotating at the end of a cycle of the previous packaging section; the item may continue to rotate due to inertia and thereby generate a tension force at the position where a previous packaging section and a latter packaging section are connected. A parting layer may be parted from the second high-adhesion layer, allowing the non-adhesive film on the latter packaging section to be unrolled, and enabling the adhesive film of the previous section to continue wrapping.

Packaging roll films and preparation methods thereof are provided. A first transparent adhesive tape layer may be capable of covering a second high-adhesion layer such that the problem caused by the exposed second high-adhesion layer may be solved. The adhesive film and the non-adhesive film may not need to completely cover the second high-adhesion layer during the process. When the roll film is unrolled for packaging an item, the rolling drum may stop rotating at the end of a cycle of the previous packaging section; the item may continue to rotate due to inertia and thereby generate a tension force at the position where a previous packaging section and a latter packaging section are connected. A parting layer may be parted from the second high-adhesion layer, allowing the non-adhesive film on the latter packaging section to be unrolled, and enabling the adhesive film of the previous section to continue wrapping.

Provided is a wound body formed by winding a long sheet. The wound body is supportable by a support shaft. The support shaft includes a cylindrical outer peripheral part that includes a first projection located at a proximal end and a second projection located at a distal end, and includes an inner peripheral part that includes a first recess part located at the one end and recessing outward in the radial direction and a second recess part located to extend from the one end to the other end and recessing outward in the radial direction. A recessing amount of the second recess part is smaller than that of the first recess part. The support shaft and the core body are integrally rotatable around the central axis by engagement of the first projection with the first recess part in a state where the core body is mounted on the outer periphery of the support shaft. The circumferential position of the first projection around the central axis is aligned with the circumferential position of the first recess part around the central axis by engagement of the second projection with the second recess part when the core body is mounted on the outer periphery of the support shaft.

Embodiments of a compressed and coreless roll of sheet product having a center indicator are disclosed. According to an embodiment of the present invention, a compressed coreless roll of sheet product is provided. The compressed coreless roll of sheet product includes a sheet product having a first end and a second end. The sheet product is wound about an axis beginning with the first end and ending with the second end to partially define an axial cavity along the axis. The first end includes an indicator that is visible when the sheet product roll is compressed such that the axial cavity is substantially collapsed.

Embodiments of a compressed and coreless roll of sheet product having a center indicator are disclosed. According to an embodiment of the present invention, a compressed coreless roll of sheet product is provided. The compressed coreless roll of sheet product includes a sheet product having a first end and a second end. The sheet product is wound about an axis beginning with the first end and ending with the second end to partially define an axial cavity along the axis. The first end includes an indicator that is visible when the sheet product roll is compressed such that the axial cavity is substantially collapsed.

To provide a biaxially oriented polyamide film, even as a product that is close to an end of a mill roll, having favorable mechanical characteristics, thermal characteristics, and few S-shape curling due to moisture absorption after being made into a bag. A biaxially oriented polyamide film formed of a polyamide resin containing not lower than 60% by mass of polyamide 6, wherein a molecular orientation angle of the film is not smaller than 20°, a strain at moisture absorption of the film is not higher than 1.3%, an impact strength of the film is not lower than 0.8 J/15 μm, and a heat shrinkage rate, after heating for ten minutes at 160° C., of the film is 0.6 to 3.0% in both an MD direction and a TD direction.

To provide a biaxially oriented polyamide film, even as a product that is close to an end of a mill roll, having favorable mechanical characteristics, thermal characteristics, and few S-shape curling due to moisture absorption after being made into a bag. A biaxially oriented polyamide film formed of a polyamide resin containing not lower than 60% by mass of polyamide 6, wherein a molecular orientation angle of the film is not smaller than 20°, a strain at moisture absorption of the film is not higher than 1.3%, an impact strength of the film is not lower than 0.8 J/15 μm, and a heat shrinkage rate, after heating for ten minutes at 160° C., of the film is 0.6 to 3.0% in both an MD direction and a TD direction.

The invention provides a heat-shrinkable polyester-based film roll obtained by winding a heat-shrinkable polyester-based film with a shrinkage ratio of 30% or more in a film main shrinkage direction in hot water at 90° C. for 10 seconds. The film roll has a winding length of 2000-25000 m and a width of 400-2500 mm. The film has a thickness of 5-40 μm. In thickness unevenness in a width direction of the film on a surface layer of the film roll, there are positions having concave thickness patterns, and in a concave portion that has a maximum thickness difference (maximum concave portion), thickness unevenness in the maximum concave portion, which is obtained from the maximum thickness difference in the maximum concave portion and an average thickness of the film is 10% or less. The winding hardness of the surface layer of the film roll is 400-800.

The invention provides a heat-shrinkable polyester-based film roll obtained by winding a heat-shrinkable polyester-based film with a shrinkage ratio of 30% or more in a film main shrinkage direction in hot water at 90° C. for 10 seconds. The film roll has a winding length of 2000-25000 m and a width of 400-2500 mm. The film has a thickness of 5-40 μm. In thickness unevenness in a width direction of the film on a surface layer of the film roll, there are positions having concave thickness patterns, and in a concave portion that has a maximum thickness difference (maximum concave portion), thickness unevenness in the maximum concave portion, which is obtained from the maximum thickness difference in the maximum concave portion and an average thickness of the film is 10% or less. The winding hardness of the surface layer of the film roll is 400-800.

An assembly is disclosed. The assembly has an adhesive layer, a protective film layer that is fused to a first side of the adhesive layer along a first length, and a cover layer that is fused to a second side of the adhesive layer along a second length. The first length is longer than the second length. The adhesive layer is wound in a roll. The second side of the adhesive layer faces outwardly from a center of the roll.