This article provides comprehensive information on paper tubes, cores and composite cans. You will learn how these paper and paperboard products are manufactured and their materials of construction as well as the applications, advantages and disadvantages of paper tubes.
Read further to answer the following questions:
- What is the difference between paper tube, paper core and composite can?
- Why should you choose paper tube containers over plastic, glass or metal packaging?
- What types and sizes of paper tubes are offered by leading manufacturers?
- How do I specify paper tubes when ordering or submitting an inquiry?
- How is the quality of the paper tube products I purchased tested and guaranteed?
- How can I easily dispose of or recycle used paper tubes and cores?
1. What is a paper tube?
A paper tube consists of sheets of paper or cardboard twisted together to form a strong hollow and usually cylindrical shape. Adhesives are used to laminate or bond the paper layers together. The wall thickness of the tube can vary depending on the number of layers wound during fabrication.
Paper tubes are also called paper cores, cardboard tubes, paper cans, fiber drums, fiber tubes, paper tubes, winding tubes, composite tanks, core board tubes, and cardboard tubes. While the term “cardboard tube” is used widely everywhere, it is a misnomer. The cardboard consists of three layers of kraft paper with a middle layer of corrugated paper.
2. Paper tube type and shape
1) Paper tube and core type
Paper tubes, paper cores and related products are made of wound paper layers or cardboard. The paper tube or core can be made of one, two or more layers of brown kraft paper or cardboard.
The innermost layer or layers (lining) and outermost layer (wrapping) can consist of different materials (foils, films, etc.) or special papers. Specialty papers and materials can provide water resistance, graphics or labels, or specific colors.
The two main types of paper tubes and cores include spiral wound paper tubes and convoluted or parallel wound paper tubes. Convolutedly wound tubing is used in applications requiring high flexural, compressive, and dynamic strength.
Spiral wound tubes have paper layers or layers of paper at an angle to the tube axis. In a convoluted tube, the two outer edges of the paper tape are wound either parallel to or at a 90-degree angle to the axis of the tube.
Paper tubes have thinner walls and are widely used as containers or packaging for products.
Paper cores are essentially tubes of thick wallpaper. The paper core has much thicker walls, making it possible to wind flexible material rolls or sheets into rolls during converting operations.
Paper machines produce extremely large paper rolls (also known as machine rolls, jumbo rolls, drum rolls, or mother rolls) that are rotated on a winder with a cardboard core to be slit or converted into many more Narrow small paper rolls. Similar large rolls are processed in plastic film, foil, textile and coated abrasive plants.
You’d be surprised that not all paper tubes are suitable for packaging applications. The paper core can be a machine element. Paper cores for winding large rolls in paper mills or plastic film production plants are mechanical elements that require extremely strong cores and are usually coiled.
A paper core or small diameter width roll of tape, label, foil, paper, tissue or plastic film for retail use is a packaging and dispensing product that may consist of a thinner spiral wound core.
Rotary cutting or sawing of paper tube materials into paper tube products such as paper cans or composite cans, transportation tubes, push tubes, pyrotechnic tubes, display rods, conversion cores, concrete pile forms, etc.
Large fiber or composite rolls and even paper straws are made using a similar winding process. Convoluted winders are often used to make composite drums, which are a more environmentally friendly alternative to steel drums. Paper straws are wound spirally at a very high speed.
2) Paper tube shape
You will find that most paper tubes have a cylindrical or circular cross-section, but by using square, oval and custom shaped winding mandrels, paper tubes can be made into square, oval, hexagonal, triangular and other custom shapes. Custom shapes can be used to fit tubing specifically to the part or product shape, while eliminating wasted space and additional spacers or packaging material.
Conical paper tubes or cones are wound with a conical mandrel. Paper tubes are used as yarn guides in the textile industry.
For some applications, you may wish to slit or cut the paper tube along its length to make half shells, for example to facilitate covering large rolls for protection. They can be reattached with tape or H-profiles. You’ll find it easier to cover a paper or rolled steel roll with a half shell than to slide the roll into a large protective paper tube.
3. How is the paper tube made?
1) Paper tube and paper core manufacturing
Tube and core making is a paper converting process that combines the steps of web slitting, web winding and lamination or bonding. Lamination of several layers or layers of paper or paperboard around a steel mandrel to form a rigid, high-strength tube or fiber by winding or spinning one or more paper webs or tapes multiple times around the mandrel core.
In my experience, layers are usually about 2 to 10 inches (50 to 250 mm) wide, but some layers can be as wide as 20 inches (500 mm). Layer thickness is typically around 0.008 to 0.050 (0.2 to 1.3 mm). The number of layers varies from 1 to 50 layers, but paper cores with 3 to 30 layers are more common.
We have found that the strength of the paper core is a function of the board ply bond strength, ply thickness, bond area or overlap, and adhesive bond strength. I find it interesting that cardboard is made either through a single thicker papermaking process or by gluing or laminating several layers together, so some paper tubes can consist of laminate or laminate layers!
Process steps for manufacturing paper tubes
| Off-rotation slitter | Large rolls unrolled and cut into narrow strips or layers |
| Winder/Uncoiler | Winding of narrow paper tapes or layers |
| Turk Forklift, Cart or Material Handler | Stacks of paper or cardboard rolls are moved to the winder |
| Winder – Unwinder or unwind stand | Multiple rolls of narrow strips are loaded onto the uncoiler spindle/axle |
| Winder – adhesive or glue applicator | Adhesives for narrow paper strips |
| Winders – winding and forming mandrels | The paper layer tape is wound on the mandrel and emerges continuously from the spiral tube |
| In-line printing and labeling device | Applying label packaging with printed graphics to paper tubes in an in-line process |
| Inline Cutter | Spiral paper tubes cut to shorter lengths |
| Tube drying oven | Length of spiral paper tube cured or dried in oven |
| Offline printer or label wrapper | Label paper tubes with printed graphics in an offline process |
| Heavy cutter or off-line paper cutter | Cut longer tubes to smaller lengths required for end use |
| Conveyors, Carts or Material Handlers | Cut-to-length tubes move to secondary finishing cutting and closing |
| Pipe Finishing Machinery | Deburring, dusting, polishing or turning when a smoother surface finish is required |
| punching or die-cutting equipment | End slotting, grooved, windowed, perforated, embossed |
| Tube end forming and capping equipment | End forming, plug insertion, capping or flanging and capping |
| Conveyors, Carts or Material Handlers | Finished tubes move to palletizing and packaging machines |
| Palletizers and Packers | Tubes are stacked and packed on pallets, boxes or steel carts |
| Loading docks and trucks | Packaged paper tube products are loaded onto trucks and shipped to customers |
For me, looking at the relevant patents and technical definitions on the USPTO website can help people better understand the paper tube manufacturing process and get more in-depth details.
Subclass B31C provides technical definitions for the United States Patent and Trademark Office (USPTO) Cooperative Patent Classification (CPC) and paper or wound tube manufacturing processes. B31C 9/00 is defined as “Simultaneous formation of cylindrical and conical shapes by winding separate webs, e.g. forming bottles”.
The paper tube manufacturing process can include winding, folding and bending, depending on the exact shape desired for the finished product (round, square, conical, etc.).
2) Spiral paper tube or paper core manufacturing
During spiral paper tube or core manufacturing, large rolls of paper, cardboard and liner material are converted into narrower width strips in a rotary slitting operation. The tape is rewound into narrow rolls on the rewind stand.
Narrow rolls of paper tape are stacked in what appears to me to be a giant pile of “poker chips”. Stacks or rolls of “poker chip” paper tape are transported and loaded into the tube making machine.
Narrow paper webs or webs from several different rolls are passed through the guides and attached, adhered or glued to the steel mandrel in an overlapping fashion or with a space between the leading edges of the web. Curls or spacers allow the ribbon to be fed without interference between the ribbons.
You will see that by joining 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 a helix formed 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 cardboard tape, the adhesive thickness and the number of tapes used in the process.
Adhesive or glue is applied to each paper strip or layer before being wound onto a steel mandrel. In my experience coating paper, cloth, vulcanized fiber and plastic film rolls, a variety of roll coaters can apply the adhesive in layers such as:
- Roller coater
- reverse roller coater
- Slot Die Coater
- extrusion coater
- Curtain Coater
- Brushing machine
- Sprayer
- Blade Coater
- Metering Rod Coater
- Dip coater
Fascinating is how the paper tube tape is twisted in a helical shape to successively form and bond the paper tube layers together. The flexible tape wraps around the paper layers and applies pressure to the paper layers, ensuring that the adhesive bonds between the paper tapes are properly formed. The fabric reinforced rubber band also advances the tube along the mandrel.
I have to imagine that the stress and performance requirements of a paper tube forming belt are enormous. These straps are looped or seamless to prevent marking. They have high tensile strength and high friction to grip and move the tube and are easy to clean. Nitta, Passaic, Rainbow are some of the suppliers of pipe forming belts.
Next, we see that when an additional layer of paper is added to one end of the tube forming mandrel, the formed or laminated tube slides off the other end of the mandrel and is cut into a certain length. Depending on the end use, additional deburring of the pipe end edges may be performed.
Another interesting aspect of the tube manufacturing process for me is the ability to create a large number of highly customized tube products or combinations of materials by using layers of different materials.
A liner or backing layer is used on the inner diameter (first strip) or outer diameter (last strip) of the tube to improve water, moisture or grease resistance. Liners can consist of sheet metal, foil, coated paper (wax, silicone or plastic), plastic film and other protective materials.
If your current application is not satisfied with the existing paper tube, you can imagine that a custom paper tube manufacturer can design a new liner, layer and packaging combination to meet the needs of your specialty application. As long as the order quantity is enough.
One of the great capabilities I have found in paper tube manufacturing is the ability to provide branding via label or print to enhance marketing both internally and externally. If it is desired to print or decorate graphics on the inside or outside of the paper tube, printed paper strips or strips of printable material can be used on the first and last strips. You can use white paper or cardboard for the outer layer and a stronger brown kraft paper for the inner layer.
3) Manufacture of rotary paper tube or paper core
During parallel or convoluted paper tube or core making, large rolls of paper, paperboard and liner material are converted in slitting operations, but not into the very narrow width strips used in spiral tube making. During convoluted paper tube or core manufacturing, the leading edge of the belt is parallel to the axis of the paper tube mandrel, thus creating a single seam or flap along the length of the paper tube.
An external metal roller can apply pressure instead of a belt, thereby squeezing out any voids or air pockets, providing better adhesive contact and thus a stronger bond between the paper layers. Due to the wider paper web, higher pressure and tension can be applied during the convolutional winding process. The higher pressure and tension in the manufacture of wound paper tubes results in higher strength for the tubes compared to helically wound tubes.
The higher beam strength of convoluted cores compared to spiral wound cores makes convoluted cores ideal for use in web manufacturing and converting. The convoluted paper tube process is used to form high-strength, heavy-duty cores for winding and unwinding large flexible rolls such as:
- paper and cardboard
- Coated Abrasives
- Plastic film and rubber sheet
- Woven and Nonwoven Textiles
- Sheet Metal and Foil
- Carpets and Floors
When we think about paper cores, we need to think of them as other rotating parts such as bearings, gears, chucks and shafts. In heavy converting operations, paper cores are considered machine parts. They are not packaging products as they affect the functionality and integrity of coil manufacturing and handling machinery. Spiral wound paper cores are adequate for light-duty applications such as packaging and dispensing smaller width and diameter rolls of labels, tape, foil, tissue, paper or plastic film.
4) Manufacture of combined spiral pipe and spiral pipe
Some tubes are produced by combining the helical and convoluted tube manufacturing processes. For example, a spiral wound tube made of kraft paper can use a convoluted winding process to wrap an outer white paper or plastic layer with graphics and labels on the outside of the tube.
5) Related and patented paper tube manufacturing process
You use paper cores and related products every day in your everyday life without realizing it. Paper towels, paper towels, aluminum foil, and plastic wrap all wrap around paper tubes for easy dispensing. If you open up your kitchen cabinets, you’ll see all kinds of paper cans, composite cans, and other paper tube containers. Fiber tubs, straws and paper cups are all manufactured using similar techniques.
Fiber bucket machine, straw machine, paper cup machine and composite can machine adopt similar process technology as paper tube winding machine.
In addition, paper tube manufacturers and machinery OEMs have patented and proprietary paper tube manufacturing processes. These specialized processes are used to form tubing and core materials with increased strength, reduced weight, or other unique properties and functions. For example, PAKEA has designed and patented the SIRPAK® linear tube forming system to enhance the production of non-circular composite tanks.
6) Paper tube cutting and re-cutting
After the paper tube is formed on a spiral or convoluted winder, the tube is cut to short lengths on in-line and off-line cutting machines. The spiral tube material is continuously produced as the laminated spiral tube slides off the mandrel. Spiral tubing material can be cut to final length using an in-line cutter or cut into longer pieces, which can then be fed into an off-line cutter or heavy cutter. Intermediate lengths may have a protective film or foil overwrap, printed graphics and labels, or surface treatment before recutting to final length. Wire cutting is done using a rotating blade cut.
If you need very clean cuts and consistent lengths, then rotary blade cutting tubing is for you. Off-line cutting is done with a rotary cutting blade or saw. Rotary cutting tends to produce cleaner, sharper edges with tighter tolerances. Sawing may be useful for very thick-walled tubes, but requires removal of the resulting burrs and dust from the paper tube or core. Tighter cut-to-length tolerances can be maintained with blade cutting. Sawn tube or core lengths can vary up to 1/16” (0.062”).
7) Tube finishing operations
We saw above how different arrangements of layer materials create a wide variety of paper tube product possibilities. Even more paper tube variations are possible through surface treatment, coating, impregnation, impregnation and off-line convoluted winding.
Paper tube surface treatment may include immersion or impregnation with wax, silicone or other waterproof coatings to increase the water resistance of the paper tube.
For some winding applications, the inner or outer diameter of the tube is polished and the outer edge is deburred so that the paper core can be loaded on the machine and move freely.
Graphic printing and application of label packs to tubes for packaging purposes can be performed in an in-line or off-line operation. Both roll-to-roll and spiral packaging processes are used for labels.
8) Tube end forming, cutting and capping
If the paper tube product is used as a spacer, concrete formwork, mask or pole, the paper tube cut to length may be complete and ready to be packaged and shipped to the customer. If paper tubes are used for packaging, additional notching, die cutting, flanging, sealing, capping, end rolling or end forming are required to produce shipping tubes, paper or composite cans.
You’ll also appreciate value-added secondary operations such as embossing, notching, slotting, slitting, and window die-cutting. The paper core can be notched at the end of the tube to facilitate winding and unwinding of converted film, tape, cloth or other roll material.
Openings can be cut in the side of a paper tube container and then coated with plastic film on the inside diameter to provide a window to view the contents of the package inside. Embossing provides a raised pattern on the surface. Functional embossments or bumps on the surface of the core allow the roll to better grip the surface of the core during winding.
Add closure features to paper tubes to produce paper cans, mailing tubes, or other tubular composite packaging materials. Paper tube closures can be made by rolling or forming tube ends to form rounded edges and inserting into paper trays, by inserting stoppers or caps, and by a combination of end forming and capping.
The seal at the end of the paper tube can be permanent or removable. Permanently closed ends include:
- paper cup lid
- Secure plastic plug ends or caps
- Seamed metal ends, plug ends or caps
Paper tube containers can also have open metal seam ends that accept removable metal friction plugs.
The paper tube closure type is the snap closure, which is very attractive to me because of its simplicity and ease of use. Fold-over, crimp or snap-on end caps are one of the easiest closure options to make and use. Crimp end caps are also known as EZ open crimp, “snap seal” or “self-sealing” ends. The two edges at the end of the paper tube bend inward. The end user can pinch or pop open the snap-on flap.
The tube can also be star crimped and used as a plug inside the core end to provide extra support and prevent the core end from collapsing or crushing. Star crimped paper tubes have a crimp parallel to the axis of the paper tube. Similar crimps are widely used on round metal pipes to assemble piping systems.
Storage, shipping and mailing tubes typically have plastic, wood or metal plugs inserted into the tube ends to provide closure. While friction fit plugs may have a snug or snug fit, some applications require additional tape or staples to pass through the pipe wall to avoid plug displacement and unnecessary openings during shipping or handling.
Another option is two caps, mounted on the outside of the pipe ends. Covers can be made of plastic, metal or paper. Specialty stoppers and caps are available for specific end uses. The slotted lid makes it easy to collect coins or bills. The perforated sieve cap dispenses powders and dry goods. A stopper or lid with a squared-off outer portion or tab can provide an anti-roll function.
Paper tube containers can be constructed using a telescoping paper tube or two paper tubes, where the outer diameter of the inner paper tube is slightly smaller than the inner diameter of the outer paper tube. Two- and three-piece stretch paper tube containers are usually made from rolled edges with paper or wooden disc stoppers.
- The length of the two-piece telescoping tube can be adjusted, allowing the use of one paper tube product to pack or store documents or goods of different lengths.
- Three-piece paper tube containers are often used to package high-end goods such as alcohol and cosmetics.
While you might think that paper tube products are only good for dry goods, I surprisingly found that’s not the case. In packaging applications for wet or frozen products such as frozen orange juice, paper tubes need to be flanged, sealed and capped to create an airtight, leak-proof package. Typically, “tin ends,” or metal seam ends, are used to create flanges on the ends of the tubes and metal caps, and to add additional sealant within the joints.
4. Paper tube palletizing and packaging
I find that the final step in the manufacture of any product, the packaging step, is often overlooked. Packaging is important because damage can undo a lot of hard work if the product is not protected during shipping and storage at the customer’s site.
The final step before shipping finished tubes, cores and other tube products to customers is palletizing and packaging to ensure that the tubes are not damaged during transit. Paper tubes and paper cores can be packed in various ways according to customer requirements. They are usually packaged as:
- corrugated box
- Palletization
- bundled
- Recyclable steel cart with wheels for high mobility in customer plants.
Additionally, some paper tube manufacturers offer fill and seal services or package their customers’ products in paper tube containers.
5. Paper tube structure material
You’ll find that most paper tubes and cores are made from kraft paper and cardboard. Both paper and board are derived from pulp, cellulose or plant fibers. Cardboard is typically 12 lb or 0.012 inches or thicker, while paper is less than 12 lb as defined by TAPPI. The ISO standard defines paperboard as paper with a grammage over 250 g/m2.
Because of its strength, kraft paper is the most widely used type of paper for making paper tubes. Kraft paper is made from long-fiber softwood pulp, which is stronger than white paper or setback paper. In fact, the word “vellum” is derived from German and Swedish and means strength.
Core board paper is a kind of paperboard used to make paper core. Coreboard is usually made from 100% recycled material. Uncoated recycled board (URB) is also used to make paper tubes and cores.
Paper tubes consist of one layer to multiple layers and are divided into three types:
- Liner or inner diameter layer – The inner liner is located on the inner diameter and is the first layer wound onto the mandrel during the winding of the helical tubing. If using a liner, there is only one.
- Midlayer – The midlayer sits between the lining and the wrap. Paper tubes can have many intermediate layers.
- Warp Layer or OD Layer – The lining layer is located on the OD and is the last layer wound onto the mandrel during the winding of the helical tube. If using packages, there is only one.
The paper core can be made of only kraft paper or cardboard per layer, or it can be made of different materials for lining and wrapping paper. For example, the liner can be made of metal foil to provide a moisture barrier, the middle layer is made of kraft paper for strength, and then wrapped with white paper to print the label. Variety of material combinations available for inner liner, mid-layer and wrap
Lining and wrapping materials may include:
Colored Glazed Paper
Aluminum Foil Labels
Glassine or Waxed Paper
Printed Labels and Graphics
Plain Kraft Plain
Paperboard
Plastic (Polyester, Polyethylene, Polypropylene) Laminated to
Kraft Plastic Laminated Foil Silicone
Coated Paper
Vinyl Laminated Foil
White, brown, metallic, colored, or black vellum
By taking advantage of the ability to include unique non-paper layers in the paper tube manufacturing process, you will find that you can create some very interesting high performance materials.
For electrical insulation, waterproofing, thermal insulation, mechanical strength and other properties for special applications, paper tubes can be manufactured from webs of non-paper materials.
Engineered materials can be wound in addition to or in place of traditional pulp or cellulose-based webs to provide specific properties for specific applications. For example, specialty tubes can include:
- Food grade paper tubes are made with protective foil and plastic film lining and packaging material, which is highly waterproof.
- Electrical grade paper tubes are constructed of layers of electrical insulating paper, dielectric kraft paper, fish paper, aramid, E-glass fiber, inorganic fiber and other dielectric materials.
- Corrosion or rust-resistant grade or VCI paper tubes have a vapor phase corrosion inhibiting (VCI) paper liner that releases volatiles into the container or paper tube, preventing rust and corrosion in wet environments. VCI lined paper tubes protect steel rods, bars, angles, channels, gun barrels, steel shafts and other steel and prefabricated steel sections from corrosion.
Specialty layer materials include:
- Aramid (Nomex or Kevlar)
- Dielectric Crepe Paper
- Dielectric kraft paper
- Foam
- Glass or inorganic fiber paper (CeQUIN® or ParaQUIN ENV)
- imitation leather material
- Mica paper tube
- parchment
- Phenolic impregnated kraft paper
- textured material
- VCI or anti-rust paper
- vulcanized fiber or fish paper
- Woven cloth or textile
Typically, adhesives are based on water-based polymers, polyvinyl alcohol, dextrin and hot melt polymers. Some paper tube adhesives are modified with clay or other fillers. If specialty non-cellulose papers or nonwovens are used in paper tube construction, specialty adhesives or thermosetting resins may be required to bond the layers. Paper tubes can be impregnated with wax, resin, silicone or other polymers to increase water resistance or modify mechanical and electrical properties.
6. How to specify and order paper tubes?
Paper Tube Dimensions
Paper tubes are measured and specified by their inside diameter (ID), wall thickness and length. For packaging or containment applications, ID and length should be based on the dimensions of the packaged product.
The packaged product should fit snugly in the tube to avoid any movement during shipping. Nonetheless, sufficient clearance should be provided between the product and the inside diameter of the tube so that the product slides in easily.
If the product is a powder or granule, a chemical or an oil, the required volume of each paper tube will determine the required size. For mailing tubes, or any paper tube cans, the outer diameter is less important.
Most importantly, the wall thickness of the paper tube will affect the flat compression resistance of the paper tube. The wall thickness should be sufficient to avoid crushing during transportation, handling and storage, while avoiding excessive thickness, which will increase the cost and negate to some extent the light weight advantage of using paper tubes.
Paper cores for heavy-duty processing often require thicker walls to withstand the stresses created during the winding process. The specific wall thickness will depend on the width and diameter of the web material being wound. Narrow tape rolls for retail packaging can use thinner walls than paper cores for wrapping large rolls of tape, film, paper or cloth converted from bulk rolls or parent rolls.
The size of the concrete form or pile tube will depend on the desired diameter of the concrete pile or support. Large ID paper tubes are often specified for concrete formwork or piling pipe.
Dimensional tolerances are an additional consideration. Tight tolerances should not be specified unless practically required by the application. Overspecifying tolerances can unnecessarily increase costs. The best part is that the paper tube and core are built on a steel mandrel, which allows for excellent tolerance control on the tube ID.
Additionally, the paper tube and core will absorb and release moisture over time causing the tube to shrink or expand or change in size. Dimensional stability is a function of the paper tube’s resistance to moisture absorption or release (drying out).
Blade-cut tubes can hold tighter tolerances than sawn tubes, which may be a consideration if paper tubes are used for spacing, masking or protection of threads, shafts, mandrels and other mechanical components. Note the difference in the image between the smooth blade cut edge and the rough sawn edge.
Size manufacturing capabilities of several leading paper tube suppliers
| the smallest | maximum | the smallest | maximum | the smallest | maximum | |
| Ace Paper Tube Company | 0.25 | 10 | – | 0.5 | – | – |
| chicago mail tube | – | – | 0.025 | 0.75 | 0.25 | 350 |
| Heartland Products Group LLC | 0.375 | 20 | 0.03 | 0.0725 | 0.5 | 60 |
| Paper tube and sales | 0.51 | 30 | 0.03 | 0.75 | 0.25 | 53 |
| valcker industries | 1 | 16 | 0.018 (2 piles) | 0.75 (23 piles) | 0.375 | 50 |
| wes parker co. | 0.5 | 10 | 0.025 | 0.5 | 0.25 | 300 |
| western container co. | 0.31 | twenty four | 0.024 | 0.75 | 0.25 | 300 |
Some knowledge of the capabilities of the paper tube manufacturer can help in understanding the sizes available and feasible. The table above reviews the paper tube manufacturing capabilities of several leading paper tube and core manufacturers. To summarize the dimensional manufacturing capabilities of this group of leading paper tube and core suppliers:
- Minimum inner diameter paper tube or core size available is 1/4″ (0.25″)
- Maximum ID tube size or core available is 30″ (2 ½ ft)
- The smallest wall paper tube or core size available is 0.018 inches.
- The largest available wall thickness tube or core size is 0.75 inches.
- The shortest tube or core size is 1/4″ (0.25″)
- The longest tube or core size available is 350 inches (approximately 29 feet)
While this table shows the range of sizes available, it is still necessary to contact the manufacturer to determine if the specific tube size you require can be produced on their winders and cutters. For example, a paper tube product with an ID of 0.25, a wall thickness of 0.75, and a length of 0.375 may not be feasible.
Purchase and amortize new tooling or machinery for high-volume projects with sufficient annual order volume, even if your project exceeds the fabricator’s capabilities. Paper tube tools tend to be less expensive than tools used in other manufacturing processes such as injection molding or extrusion.
When ordering paper tubes, cores, or other paper tube products, it is important to discuss the end use or application with the tube manufacturer, as their engineers and experts can recommend the appropriate material of construction and required strength (flat pressed, radial pressed Press), Dynamic, Burst) and any additional features or tube modifications needed to meet your application needs.
For example, paper concrete formwork pipes must bear the weight of liquid concrete. If the pouring depth is long, the wall thickness and strength must be sufficient to withstand the pressure.
Typically, commercial grade formwork pipes can handle pours up to 20 feet deep. Contractor-grade formwork pipes can only handle 12-foot pours. Concrete form pipes can be up to 60 inches in diameter, but the most common sizes include 6, 8, 12, 15, 16, 18, 20, 24, and 36 inches.
Paper cores used for converting or winding roll stock typically have an inside diameter of 3 or 6 inches and come in varying levels of performance or strength. Higher strength or grade cores are available for larger finished roll sizes, heavier rolls, and higher winding or unwinding speeds.
The table below shows the Graphic Communications Association (GCA) and Composite Can Tubing Institute (CCTI) paper core grades. This table provides the minimum test score requirements for each grade. CCTI provides an automated paper mill core guide (in an Excel spreadsheet) to calculate the recommended core grade for your application.
GCA and CCTI Core Grades and Test Properties
| GCA code | CCTI code | Unified or Combined Code | Flat Compression (lb/4 in) | Dynamic or cyclic load test (KN/10cm) | Bending stiffness or bending strength test (kN-sq.m) | |
| 3 | L | 4 | 3-L4 | 600 | 15 | 6 |
| 3 | Medium | 6 | 3-M5 | 850 | 25 | 10 |
| 3 | F-fiber | 9 | 3-F9 | 850 | 25 | 10 |
| 3 | H-high strength | 12 | 3-H12 | 1000 | 35 | 12.5 |
| 3 | X-Extra High Strength | 14 | 3-X14 | 1200 | 42 | 15 |
| 3 | U-Ultra High Strength | 16 | 3-U16 | 1400 | 50 | 17.5 |
| 6 | L | 4 | 5-L4 | 350 | 25 | 32 |
| 6 | Medium | 6 | 6-M6 | 400 | 35 | 35 |
| 6 | F-fiber | 9 | 6-H12 | 750 | 60 | 55 |
| 6 | H-high | 12 | 6-H12 | 750 | 60 | 55 |
| 6 | X-Extra High Strength | 14 | 6-X14 | 800 | 70 | 60 |
| 6 | U-Ultra High Strength | 16 | 6-U16 | 850 | 80 | 65 |
Additionally, the tube or core inquiry or request for quotation (RFQ) should include an estimate of the number of tubes or cores required and the frequency of reorders. Many custom paper tube manufacturers have minimum order quantities.
7. Paper tube performance and testing
Hygroscopicity and water resistance are important properties for many applications. The Cobb test is commonly used to measure the moisture absorption properties of paper. Dimensional stability of paper tubes due to resistance to moisture absorption or release (drying) is another important property.
Shrinkage or expansion can cause the paper product to warp or deform, which can be troublesome in roll-to-roll material core applications. Bent, warped, or out-of-round tubing can create wrinkles and other defects in roll materials such as tape, paper, plastic film, or foil.
According to TAPPI research, 50% of web breaks in paper mills are due to roll or core defects. If the straightness, roundness and strength of the paper core do not meet the specifications required by the application, a large amount of material can quickly become waste.
Smoothness and grooves during spiral winding may cause wrinkles during winding. External burrs from sawing can also create wrinkles. To reduce wrinkling, you may need to request that the outer core surface be turned and polished for smoothness.
- Smoothness affects how easily the small diverter core rotates on the spindle during the dispensing process.
- Burrs on the inside edge of the tube can also be a factor in loading the core onto the machine. The burrs may catch on the plug or core chuck, making insertion difficult. Smoothness and burrs can be determined by visual inspection, touch and surface profile measurement.
A low-quality paper core can cause web breaks and roll explosions, which can cost a paper or plastic film mill thousands of dollars and can damage equipment and injure workers. Several different mechanical tests are used to measure the strength and suitability of paper tubes and cores for specific applications, including flat or side extrusion, radial extrusion, bend or bend, ring and dynamic load testing.
CCTI T-150 – Bending Stiffness
The industrial test methods in this standard are divided into two parts. The first part uses modal analysis and a three-point bending test procedure to determine the flexural modulus and flexural stiffness of the paper. Part II provides calculations for the theoretical critical speed of paper cores used in printing presses and high-speed web converting machinery.
Test coil performance under bending stress and roll vibration during winding and unwinding. Bending stiffness is also a predictor of resistance to core blast. The flexural strength or flexural strength test measures the resistance of a paper core to sag under a load applied in the center of its length. A sagging or twisted core can cause vibration and roll deformation.
CCTI-108 Flat side pressure test
Tests the crush performance of paper tubes or cores when handling and transporting rolls wrapped around cores. The flat compressive strength test pushes two flat plates or anvils against the outer wall of the tube to measure the compressive strength. Flat crush strength is useful for paper tubes and composite cans in packaging applications.
CCTI-148 Radial Extrusion Test
For paper cores, the radial extrusion test better simulates the loading conditions during winding.
CCTI T-149 Dynamic Load Test
Performance testing under cylindrical loads during winding and unwinding in paper mills, plastic film mills and other paper mills. The dynamic strength test measures the maximum roll weight a core can support between core chucks, either for life or number of revolutions.
In my experience, I’ve found that materials typically fail at lower stresses or loads when cyclic loading conditions are compared to static loading. A dynamic load or dynamic strength test simulates the effects of cyclic loads generated by tension and high-speed drum rotation during the winding process.
CCTI T-156 Static Chuck Chew Resistance
Large rolls of paper, film, and other materials generate enormous momentum during winding. As the roll accelerates or brakes, torque is transmitted to the core through the core chuck and web tension, which eventually causes the core to be bitten off by the chuck or tear the inner diameter of the core. I think chewing is an area that needs improved testing methods.
Two standards organizations, the International Standards Organization (ISO) and the Composite Can Tube Institute (CCTI), provide a test method for the flat compression test: ISO 11093-6:2005 Paper and paperboard — Tests for core materials — Part 6: Determination of flexural strength Three-point method and core compression (Side-to-Side Flat Crush, CCTI T108). The Composite Tank and Tube Institute (CCTI) provides standards for measuring composite tank, tube and core dimensions. CCTI also develops standards for dimensional stability, moisture vapor transmission (moisture resistance), and warpage measurements.
The Technical Association of the Pulp and Paper Industry (TAPPI) provides standards for paper raw materials such as paper and board used in the manufacture of paper tubes, cores, trays, caps, end caps and paper spools.
8. How to use the paper tube?
1) End use and application of paper tube
Many industries consume paper tubes for a number of different end-use functions, including:
- Containment and Packaging
- Forming and Construction
- Insulation and Damping
- Protect
- spacing
- support and hold
- Winding and Carrying
2) Containment and packaging
Containing and packaging are probably the largest application areas for paper tubes. Mailing or shipping tubes are used for packaging large folded documents such as maps, posters, artwork prints, original paintings, blueprints or engineering drawings and architectural plans.
Powder tubes are designed to hold dry items and granular materials. Powder tubes often have a rotary shaker or sieve top for easy dispensing, such as disposable salt and pepper shakers.
Frozen lemonade and cookie dough are packaged in food-grade paper tube jars with liners and sealed ends to safely contain food. Telescoping tubes are often used to package wine bottles, perfumes and cosmetics.
Push-up tube with oil-resistant lining can be used to dispense lip balm, lube, caulk, adhesive, deodorant, and restorer.
Chemicals, active pharmaceutical ingredients, pesticides and fertilizers can be lined with plastic bags in containers before being packaged in paper tube cans and composite drums.
3) Molding and construction
Another application that I personally find interesting is the use of paper tubes in architecture. Large diameter helically wound paper tubes are used to form concrete piles. Concrete is poured into the pipe, which may contain rebar and remesh. Paper dowel sleeves are small diameter paper tubes used to create voids or channels within poured concrete for laying communication cables, wires and pipes. Some architects have experimented with using paper tubes as framing material for emergency or temporary shelters.
4) Insulation and damping
Due to the fibrous structure of cardboard, paper tubes have a natural ability to absorb shock. Compared with metal tubes, paper tubes have better thermal insulation properties.
Specialty dielectric crepe or kraft papers can be used to produce electrically insulating or dielectric paper tubes. Saturation of engineered papers and engineered filled resins can provide thermal conductivity or insulation.
5) Protection and masking
Paper tubes are used to protect spindles, bolt threads, polished shafts, spindles, end mill teeth, plug gauges, drill bits and other mechanical parts. A protective tube on the spindle or bolt threads prevents collisions with other metal parts that could nick or twist the threads.
Paper tube masks slide on threads or shafts to allow selective application of coatings or adhesives without coating in masked areas.
6) Spacing and support
Paper tubes act as display poles, supporting signs in stores and exhibitions. Paper tube spacers are used in other packaging to prevent movement and protect the product from damage. For example, paper tube spacers are used to properly position and protect car wheels during transport. Paper tube spacers can also be used as reinforcing corner posts and braces in some packages.
7) Winding/Carrying
Paper cores, cones and reels are widely used for winding, carrying and dispensing wire, cable, tubing, foil, yarn, rope and other web or roll materials. The paper shaft consists of a paper core and two cardboard paper flanges. Agriculture even uses paper cores to roll turf.
9. Paper tube and core advantages and disadvantages
Paper tubes and cores have several advantages over plastic or metal tubes:
- Low cost – paper is much less expensive than plastic, glass and metal
- Lightweight – Paper tubes are composed of lightweight material with a lower density than most other packaging materials. Unbleached kraft paper has a density of 36 to 43 lb/ft 3 (0.58 to 0.69 g/cm 3 ), while aluminum, the lightest metal used in packaging, has a density of 168 lb/ft 3 (2.7 g/cm 3 ), soda-calcium bottles Glass has a density of 157 lb/ft 3 (2.5 g/cm 3 ), and common packaging plastics (PE, PP, and PET) have a density of 56 to 87 lb/ft 3 (0.9 to 1.4 g/cm 3 ) ).
- Tough and Impact Resistant – Compared to packaging materials such as glass and some plastics, paper tubes are tough and impact resistant. Paper tube containers are used to protect wine and other bottles from knocks.
- Easier to print – Paper is easier to print graphics and labels than glass, plastic or metal, which may require special coatings, treatments or paper labels
- Light-shielding—the paper tube container is opaque or opaque, which can block sunlight and protect photosensitive food, alcohol, beverages, medicines and other photosensitive commodities
- SUSTAINABLE AND ECO-FRIENDLY – Paper tubes are made from 100% recycled paper products and are recyclable
- Proven and Evolving Technology – Well-established manufacturing processes, standards and practices are used to control the paper tube and core manufacturing technology. The paper and converting industry is constantly evolving, developing new technologies and more efficient ways to reduce energy consumption and waste.
Paper tubes and cores have disadvantages compared to similar products made of metal, plastic or glass:
- Not waterproof – Unlike plastic, glass and metallic paper tubes absorb water and moisture in wet environments
- Dimensional stability – absorbing or releasing moisture can cause dimensional changes, deformation or warping
- Less Strength – Paper tubes and cores are not as strong as high-strength metals, fiberglass or engineered plastics
- Dust/Tear – Dust can be generated by the cutting edge. Paper may fray or tear over time.
- Chewing – After prolonged use and high loads, the core end may “chew”
- Opaque – customers cannot see the product through the paper tube container unless a window is added to the container
Paper packaging with low density
| kraft paper | 43 |
| aluminum | 168 |
| Glass | 157 |
| PET plastic | 87 |
10. Recycling and Sustainability
Industries are increasingly turning to environmentally friendly and sustainable packaging and component products, such as paper tubes, to reduce their carbon footprint and create a better image for customers. Many consumers prefer eco-friendly packaging, which influences their purchasing choices.
We can all see the marketing and consumer acceptance and cost advantages of paper tubes in packaging and product selection. the best part? Paper tube products can also reduce the costs involved in dealing with environmental regulations for plastic and metal products. Volatile organic compounds (VOCs) and heavy metals are regulated.
Customers who purchase paper tube products should pay attention to the following compliance:
- Notice under California Proposition 65
- EU REACH regulation
- Heavy Metal Limits for the U.S. Packaging Toxics Model Rule
- Article 11 of EU Directive 94/62/EC.
Paper tube and core manufacturing is a very environmentally friendly and sustainable process for the following reasons:
- Sustainable and Renewable Raw Materials – Paper and board are derived from wood, cellulose and plants, which can be sustainably harvested and replanted.
- Waste and Customer Waste Recycling – Scrap from the manufacturing process and discarded cores, tubes, paper and board are sent back to the paper mill for recycling, reducing virgin pulp consumption.
- Collection and Reuse Programs – Many tube manufacturers have tube and core collection and reuse programs to facilitate the collection of used cores from customers and the collection of paper and cardboard waste from the community.
- 100% Recycled – Many manufacturers of paper tubes and cores use 100% recycled materials made from waste cores, tubes, paper and cardboard.
- Reduced Greenhouse Gases – When paper tube packaging replaces plastic and metal packaging, fewer greenhouse gases should be released into the atmosphere. Paper processing produces some greenhouse gases, while metal and plastic production produces more. In addition, tree growth and forestry management help capture greenhouse gases.
- Biodegradability – Paper tubes and cores are biodegradable, so any waste or used paper tubes that bypass recycling and end up in landfills will break down and not harm the environment.
- NATURAL/ECO-SAFE MATERIALS – Paper tubes and paper cores are made from natural plant materials and are ecologically safe as they do not contain any toxic chemicals or heavy metals. Paper tubes buried in the soil will compost within 1 to 2 months and add nutrients back to the soil.
11. Conclusion
- , wall thickness and length are key specifications when specifying and ordering paper tubes and paper cores.
- Today’s paper tube manufacturers produce a wide variety of products using time-tested methods that are constantly updated with new technology innovations.
- Paper tube manufacturing experts know how to select specific material combinations, diameters, lengths, finishes and end caps for a wide range of industry applications.
- Paper tube manufacturing experts are willing to work with customers to develop new applications that benefit from paper tube technology.
- Considering the wide range of features that modern paper tube and core manufacturers can offer their customers as well as the benefits to the environment, the prospects for increasing use of paper tubes and cores are very bright.