PRODUCTION OF PARALLEL PAPER TUBES

Paperboard tubes are ubiquitous and are found in every aspect of modern-day life. In the industry, the terms paperboard “tube” and paperboard “core” are used interchange-ably. They are produced for a myriad of industrial applications and consumer products and are sometimes considered to be commodity products, but most are actually highly engineered. On a global basis, the majority of paper tubes are used in industrial winding operations. In these applications, immediately after being manufactured, either paper, film, or textile yarn is wound directly onto paper tubes. The paper tube helps the wound material develop a stable roll structure and enables transportation of the manufactured material to a converting operation. These tubes range from small (10- to 25-mm diameter with 0.5- to 1.5-mm wall thickness) to wind paper, plastic, aluminum, cloth, and yarn consumer products, to large industrial cores (70- to 200-mm diameter having10- to 25-mm wall thickness) to wind rolls of printing paper, plastic film, textiles, and specialty metals. Such tubes are designed to be used in interior environments for winding, transportation, and finishing operations; not exterior environments where they are exposed to rain or high humidity. Most tubes for industrial markets are structurally optimized and engineered products. This is achieved by selecting proper paper-board strength and stiffness, tube thickness, ply positioning in the wall, and adhesive type in the design process. For example, certain paper mill cores are designed both for fatigue strength to support a heavy cyclic load from winding a large roll of paper and for sufficient axial modulus to prevent core vibrations when unwinding the paper roll on high-speed rotogravure presses. Such cores generally require thick walls (10e16 mm) and fabrication from high strength paperboards.

Paper tubes are defined as cylindrical containers made from cardboard that vary in thickness and size. These containers are used by a multitude of industries for countless applications because of their versatility and cost-effectiveness. For items that can either be rolled into a cylindrical shape or folded up to fit into a cylindrical container, paper tubes are useful containers for distributing, manufacturing, and shipping. Industries that use paper and cardboard for their applications include food, electronics, and automotive. They can be used in any department from distribution, insulation, parts protection, or storage.

The paper tubes are broadly classified into a spiral type and a flatwise type. The spiral paper tube is formed by spirally winding a thin paper web around the outer circumference of a mandrel to a predetermined thickness. In contrast, the flatwise paper tube is formed by winding a paper web around the outer circumference of a mandrel in a direction perpendicular to the axis of the mandrel.

The flatwise paper tubes are further classified into a multi-layer type with a paper web wound in several layers to a predetermined thickness, and a single-layer type with a paper web wound in a single layer. The single-layer flatwise paper tube has a lapped portion where both side edges of the paper web are lapped and bonded with each other.

The spiral paper tube and the multi-layered flatwise paper tube have a rigidity which allows them to serve as the pipe member of the flavor inhaler. However, since such paper tubes are manufactured with an adhesive applied to the entire surface of the paper web, they contain a large amount of the adhesive which sorbs flavor components, and are therefore unsuitable as the pipe member of the flavor inhaler.

On the other hand, the single-layered flatwise paper tube contains an adhesive only in the lapped portion, and is suitable as the pipe member of the flavor inhaler in terms of sorption of flavor components. However, due to its lower rigidity compared with that of the spiral paper tube or the multi-layered flatwise paper tube, the single-layered flatwise paper tube is not suitable as the pipe member of the flavor inhaler. In this regard, using a thick paper web to manufacture the single-layered flatwise paper tube is likely to increase the rigidity of the flatwise paper tube.