- Created: 07-12-21
- Last Login: 07-12-21
User Profile
viterrcu102
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.