The cardboard is cut into ribbons which are combined with adhesives to increase the durability of the material. The ribbons are then wound around mandrels into a hollow tube or cylinder according to the desired diameter and length.
Mailing tubes can be used for letters, documents, paintings, magazines and any type of article that can fit into a cylindrical shape. The spiral binding of the cardboard gives added structural strength and prevents the paper tube from collapsing during transit. This is a weak point of cylinders, especially those with longer lengths.
Most tubes offer superior protection from the denting, bumping and dropping that often occurs during shipping, since shipping tubes are more difficult to dent than cardboard boxes. Mailing tubes are usually denser, thicker and stronger than cardboard walls, and the cylindrical shape offers more strength than a square box. Items which are commonly shipped in mailing tubes are posters, blueprints, signs, banners, paintings, artwork, pencils and small fragile items.
Typically, tubes are manufactured to wide ranges of diameter, length and thickness according to the item being mailed but are defined by their interior measurements. It is important to consider this when determining which size of tube to obtain as some tube can have thicker walls than others. Often mailing tubes have multiple layers for added strength and protection, especially for valuable or secure items, and many manufacturers offer decorative coating, papering and printing options for the tube’s outer layer.
Typical tubes are cardboard brown, but their exteriors can be papered in almost any color, pattern, or print. Bright colors and prints on tubes are popular for mailing birthday, anniversary, wedding or Christmas presents although they will typically be slightly more expensive than the regular brown tubes.
Cardboard tubes intended to ship industry-specific items, such as medical specimens, hazardous chemicals or other sensitive materials, are often coated with aluminum interiors both for the protection of the contents and in order to comply with US Postal regulations. These specialty tubes will are not widely available however and may need to be custom ordered.
Depending on the item being mailed, mailing tubes may be closed at both ends with glued or removable metal plugs, plastic caps, wooden plugs or by simply crimping the ends of the paper tube. Industries often use paper mailing tubes for sending and receiving parts to and from manufacturers as well as for packaging and distribution.