Paper Tube Winding Machine

Overview

A paper tube winding machine builds rigid paper tubes and cores by wrapping several narrow strips of paper, called plies, around a fixed steel rod at an angle. The plies are glued together as they wrap, so the finished wall is a solid laminate of many layers. Because the plies feed on at an angle and the tube both rotates and slides forward, the seams spiral down the tube rather than running straight, which is why the method is called spiral winding. The result is the cardboard core at the centre of a roll of tape, paper, or film, and the heavier tubes used for posters, textiles, and concrete forming.

Paper feeds from the Ply Reel Stands, is coated at the Glue Unit, and wraps around the Winding Mandrel driven by the Belt Winding Head head. The Flying Cutoff Saw saws the moving tube to length, the Runout and Conveyor carries it away, and the Drive and Control runs the whole cycle.

Feeding the plies

Each layer of the tube comes from its own reel on the Ply Reel Stands. A tube with eight plies needs eight strips arriving together. Each reel sits on a Ply Reel Shaft held back by a Ply Brake so the ply stays under tension, and a Ply Guide Roll aligns it to the angle at which it meets the mandrel. A Ply Slitter can cut wide parent reels into the narrow plies the winder needs. The ply width and the wrap angle together decide how the seams overlap and stagger through the wall, which sets the strength of the finished tube.

Gluing the layers

The tube holds together because every inner ply is glued to the one outside it. The Glue Unit coats them: each Glue Roll wipes adhesive from a Glue Trough onto one ply, with a Doctor Scraper doctor blade metering the film and a Glue Pump keeping the glue circulating. Sodium silicate gives a stiff, fast-grabbing bond for heavy industrial tubes, while PVA or dextrin suits lighter cores. The innermost and outermost plies are often left dry or printed, so glue is applied only to the layers that need to bond. Glue coverage and water content set both bond strength and how fast the wound tube dries.

The mandrel and winding head

The tube forms on the Winding Mandrel, a polished hardened Mandrel Bar whose diameter sets the tube bore. The mandrel is fixed and cantilevered from its Mandrel Mount, and an Air Lubrication bleed floats the tube slightly so it slides along with less friction. The Belt Winding Head does the work: a Winding Belt wraps around the mandrel in a crossed loop, and as it runs it both rotates the plies around the mandrel and pulls the forming tube along it. The Wind Angle Adjuster sets the belt crossing angle, which is the master setting, since it determines tube diameter, wall build, and feed speed together. A Belt Tensioner keeps the belt gripping the tube.

Cutting on the fly

Because the tube comes off the mandrel as a continuous length that never stops, it must be cut while moving. The Flying Cutoff Saw is a flying saw: a Cutoff Blade on a Saw Motor rides on a Flying Carriage that accelerates to match the tube speed, makes a square cut, and returns. A Length Encoder measures tube travel and triggers the cut at the set length, so every tube comes off the same length without stopping production. The carriage runs on a Linear Guide Rail pair driven by a Ball Screw for precise tracking.

Runout, drive, and control

Cut tubes drop into the Runout and Conveyor section. A Runout Trough off the mandrel end supports the tube, a Tube Kicker pushes it clear, and a Take-Away Conveyor carries it away to dry. Wound tubes hold water from the glue, so they are usually stacked to air-dry or pass through a drying tunnel before they reach full strength. The Drive and Control turns the belt head and saw, and the Machine PLC holds the recipe: wind speed, tube length, and the saw trigger. Length and bore are programmed so a change of product is a setting change rather than a rebuild.

Tube grades and use

By changing the mandrel diameter, the number of plies, and the glue, one machine makes a wide range of products. Thin two- or three-ply cores wind into the centres of adhesive tape, label, and film rolls. Thicker walls make the cores that carry heavy paper and textile rolls, and the heaviest tubes serve as mailing tubes, poster tubes, and single-use concrete column forms. Spiral winding suits long continuous tube made to a programmed length, while a related parallel-wound method makes short composite cans. Bore accuracy, wall strength, and cut squareness are the measures buyers check, since a core that is out of round or out of length jams the converting line it feeds.