Introduction
This article provides comprehensive information about

paper tubes, paper core and

composite cans. You will learn how these paper and paperboard products are made and

their materials of construction as well as paper tube applications, advantages and

drawbacks.
Read further to answer questions like:
What‘s the difference between paper tubes, paper tubes and composite cans?
Why should you select paper tube containers instead of plastic, glass, or metal

packaging?
What types and sizes of paper tubes are available from leading manufacturers?
How do I specify paper tubes when ordering or submitting an RFQ?
How is the quality of paper tube products I am buying tested and assured?
How easily can I dispose of or recycle used paper tubes and paper cores?
And much more...
Paper Tubes
Paper Tubes from Ace Paper Tube
I. What is a Paper Tube?
Paper tubes consist of paper or paperboard sheet layers wound together to form

strong, hollow, and usually cylindrical shapes. The paper layers are laminated or

bonded together using adhesives. The wall thickness of the tube can vary depending on

the number of layers wrapped during manufacturing.
Paper tubes are also known as paper cores, paperboard tubes, paper cans, fiber

drums with paper drum machine, fiber tubes, paper tubing,

wound tubes, composite cans, coreboard tubes, and cardboard tubes. While widely used

everywhere, the term "cardboard tube" is a misnomer. Cardboard consists of

three kraft layers with the central layer corrugated.
II. Paper Tube Types and Shapes
Paper Tube and Core Types
While paper tubes, paper cores and related products are all made from wound plies

of paper or paperboard. Paper tubes with paper tube cutting

machine or cores can be constructed from one, two or many plies of brown kraft

paper or paperboard.
The innermost layer or ply, the liner, and the outermost layer, the wrap, can

consist of different materials (foil, film, etc.) or specialized paper. The

specialized paper and materials can provide water resistance, graphics or labeling,

or a specific color.
The two main types of paper tubes and cores include spiral wound and convolute or

parallel wound paper tubes. Convolute wound tubes are used in applications requiring

high bend strength, crush resistance and dynamic strength.
A spiral wound tube has the paper ply or plies wrapped around at an angle to the

tube's axis. In convolute tubes, the outer two edges of the paper strip are

wrapped parallel or at a 90-degree angle to the tube‘s axis.
Paper tubes have thinner walls and are widely used as containers or packaging for

products with

paper packaging machine.
A paper core is essentially a heavy-walled paper tube. The much thicker wall of

paper cores enables their use in winding webs or sheets of flexible material into

rolls in converting operations.
Paper machines produce extremely large rolls (also known as machine, jumbo,

tambour or mother rolls), which are rotary slit or converted into many narrower

smaller rolls on a winder with a paperboard core. Similar jumbo rolls are converted

in plastic film, foil, textile and coated abrasive plants.
You will be surprised that not all paper tubes are geared toward packaging

applications. Paper cores can be machine elements. Paper cores used for winding large

rolls in a paper mill or plastic film production plant are machine elements and

require extremely high strength paper cores, which are often convoluted.
Paper cores for retail or small diameter width rolls of adhesive tape, label,

foil, paper, tissue or plastic film are a packaging and dispensing product, which can

consist of a thinner, spiral wound core.
The paper tube material is rotary or saw cut into paper cans or composite cans,

shipping tubes, push tubes, pyrotechnic tubes, display poles, converting cores,

concrete piling forms, and other paper tube products.
Large fiber or composite drums and even paper straws are manufactured in a

similar winding process. Convolute winders are typically used to make composite

drums, which are a more eco-friendly alternative to steel drums. Paper straws are

spiral wound at very high speeds.
Paper Tube Shapes
You will find that most paper tubes have a cylindrical shape or round cross-

section, but paper tubes can be made with square, oval, hexagonal, triangular, and

other custom shapes by using a square, oval and custom shaped winding mandrel. Custom

shapes are useful for fitting the tube specifically to a part or product shape while

eliminating wasted space and additional spacers or packing material.
Tapered paper tubes or paper cones are wound with a cone-shaped mandrel. Paper

cones are used as yarn carriers in the textile industry.
For certain applications, you may want your paper tubes slit or cut along their

length to make half-shells such as facilitates covering large rolls for protection.

They can be reconnected with tape or h-profiles. You will find covering a paper roll

or coiled steel roll easier with half-shells compared to sliding a roll into a large

protective paper tube.
III. How Are Paper Tubes Made?
Paper Tube and Core Manufacturing
Paper tube and core manufacturing is a paper converting process combining web

slitting, web winding and lamination or adhesive bonding steps. Through multiple

wraps or revolutions of one or more paper webs or ribbons around a steel mandrel,

several layers or plies of paper or paperboard are laminated together around a steel

mandrel to form rigid, high strength tubes or fiber cores with

paper core making machine.
In my experience, plies are usually around 2 to 10 inches (50 to 250 mm) wide,

but in some plies are as wide as 20 inches (500 mm). Ply thicknesses are typically

around 0.008 to 0.050 (0.2 to 1.3 mm). The number of plies ranges from 1 to 50 or

more, but paper cores with 3 to 30 plies are more common.
We find that the strength of paper core is a function of the paperboard ply bond

strength, ply thickness, bond area or overlap and adhesive bond strength. What I find

interesting is that paperboards are made in a single thicker papermaking process or

by bonding or laminating several plies together, so some paper tubes can consist of

laminations or laminated plies!
To me, a review of related patents and technology definitions in the USPTO

website can help provide a greater understanding and in-depth details on the paper

tube making process. Subclass B31C provides the United States Patent and Trademark

Office (USPTO) cooperative patent classification (CPC) and technology definitions for

paper or wound tube manufacturing processes. B31C 9/00 is defined as

"Simultaneous forming of cylindrical and conical shapes by winding separate

webs, e.g. forming bottles".
The paper tube making process can include winding, folding and bending depending

on the specific shape (round, square, conical, etc.) desired in the finished end

product.
Spiral Paper Tube or Core Manufacturing
In the spiral paper tube or core manufacturing process with

paper core machine

, jumbo rolls of paper, paperboard, and lining materials are converted in a

rotary slitting operation with paper slitting machine into narrower width ribbons. The paper

ribbons are rewound into narrow rolls on rewinding stands.
The narrow paper ribbon rolls are stacked in what looks to me like giant stacks

of "poker chips". The "poker chip" stacks or rolls of paper

ribbon are transported and loaded into the tube manufacturing machine.
Narrow paper webs or ribbons from several different rolls are passed through

guides and attached, adhered or taped to a steel mandrel in an overlapping fashion or

with spacing between leading edges of the paper ribbons. The festooning or spacing

allows the ribbons to feed without interference between ribbons.
You will see that by attaching the leading edge or end of the ribbon obliquely or

at an angle less than 90 degrees to the axis of the mandrel, the result is the

formation of spiral during winding.
The outer diameter of the steel mandrel determines the inner diameter of the

finished paper tube. The wall thickness of the tube is a function of the thickness of

the paper or paperboard ribbons, the adhesive thickness and the number of ribbons

used in the process.
Adhesive or glue is applied to each paper ribbon or ply before being wound onto

the steel mandrel. In my experience coating webs of paper, cloth, vulcanized fibre

and plastic film, a variety of web coaters can apply the adhesive to the plies such

as:
Roll coaters
Reverse roll coaters
Slot die coaters
Extrusion coaters
Curtain coaters
Brush coaters
Spray coaters
Blade coaters
Metering bar coaters
Dip coaters
What‘s fascinating is how the paper tube belt twists around in a helical shape

to continuously form and bond the paper tube plies together. The flexible belt wraps

around and applies pressure to the paper layers, which assures the proper formation

of adhesive bonds between the paper ribbons. The fabric reinforced rubber belt also

advances the tube forward along the mandrel.
I have to imagine that the stresses and performance requirements on the paper

tube forming belt are enormous. These belts are endless or seamless and prevent

marking. They have high tensile strength and high friction to grab and move the tube

along and easy to clean. Nitta, Passaic, Rainbow are some of the suppliers of tube

forming belts.
Next, we see that as additional paper plies are added at one end of the paper

tube forming mandrel, the formed or laminated paper tube slides off the other end of

the mandrel and is cut to length using rotary blade slicing or offline sawing

operations. Additional deburring of the tube end edge may be performed depending on

the end-use.
Another interesting aspect of the paper tube manufacturing process to me is the

ability to make an enormous amount of highly customized paper tube product or

materials combinations by using different material plies.
Liner or lining layers are used on the inner diameter (first ribbon) or outer

diameter (last ribbon) of the tube to improve water resistance, moisture resistance

or grease resistance. Liners can consist of metal sheet, foil, coated paper (wax,

silicone, or plastic), plastic film and other protective materials.
If your current application is not satisfied with existing paper tubes, you can

well imagine a custom paper tube manufacturer can engineer a new combination of

liners, plies and wraps to meet the needs of your specialized application. As long as

the order volume is sufficient.
One great ability I find in paper tube manufacturing is the ability to provide

branding through labeling or print to enhance marketing inside and out. If printed or

decorative graphics are required on the inside or outside of the paper tube, then the

printed paper ribbons or ribbons made of printable material can be used on the first

and last ribbons. A white paper or paperboard could be used on the outer layer with

stronger brown kraft paper used on the inner layers.
Convolute Paper Tube or Core Manufacturing
In the parallel or convolute paper tube or core manufacturing process, jumbo

rolls of paper, paperboard, and lining materials are converted in a slitting

operation, but not into the very narrow width ribbons used in spiral tube

manufacturing. In the convolute paper tube or core manufacturing process, the leading

edge of the ribbon is parallel to the axis of the paper tube mandrel, so a single

seam or flap along the length of the paper tube results.
An external metal roll can apply pressure instead of a belt, which squeezes out

any voids or air pockets providing better contact of the adhesive and therefore a

stronger adhesive bond between paper plies. Since the paper web is wider, higher

pressures and tension can be applied in the convolute winding process. The higher

pressures and tensions in convolute paper tube manufacturing result in tubes with

higher strength compared to the spiral wound tubes.