This article provides comprehensive information about paper tubes. You will learn how these paper and board products are manufactured, their materials of construction as well as paper tube applications, advantages, and disadvantages.
1. What is a paper tube?
Paper tubes consist of layers 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 wrapped during fabrication.
Paper tubes are also called paper cores, cardboard tubes, paper cans, fiber drums, fiber tubes, paper tubes, winding tubes, composite tanks, cardboard tubes, and cardboard tubes. While widely used everywhere, the term “cardboard tube” is a misnomer. The cardboard consists of three layers of kraft paper, and the middle layer is corrugated.
2. The advantages of paper tube
Paper tubes and wicks have several advantages over plastic or metal tubes:
1) Low cost
Paper is much less expensive than plastic, glass, and metal.
2) Lightweight
Paper tubes are made from a lightweight material that is less dense than most other packaging materials. Unbleached kraft paper has a density of 36 to 43 lb/ft3 (0.58 to 0.69 g/cm3), while aluminum, the lightest metal used for packaging, has a density of 168 lb/ft3 (2.7 g/cm3), soda lime glass Bottled at a density of 157 lb/ft3 (2.5 g/cm3), common packaging plastics (PE, PP, and PET) range in density from 56 to 87 lb/ft3 (0.9 to 1.4 g/cm3).
3) Tough and impact resistant
Compared to packaging materials such as glass and some plastics, paper tubes are tough and impact-resistant. Wine and other bottles are protected from knocks with paper tube containers. I have a client who is a smart lock supplier. He told me that in order to protect the lock core from damage during transportation, paper tube packaging is a good way.
4) Easier to print
Paper is easier to print graphics and labels on than glass, plastic, or metal which may require special coatings, treatments, or paper labels.
5) Shading
Paper tube containers are opaque or opaque, which can block sunlight and protect photosensitive food, wine, beverages, medicines, and other photosensitive items.
6) Sustainable environmental protection
The paper tubes are made from up to 100% recycled paper products and can be recycled.
7) Mature and evolving technology
Well-established manufacturing processes, standards, and practices are used to control paper tubes and core manufacturing techniques. The paper and converting industry is constantly evolving, developing new technologies and more efficient ways to reduce energy consumption and waste.
3. Disadvantages of paper tubes
Compared to similar products made of metal, plastic, or glass, paper tubes, and cores have the following disadvantages:
1) Not waterproof
Unlike plastic, glass, and metal paper tubes can absorb water and moisture in wet environments.
2) Dimensional stability
Moisture absorption or release can lead to dimensional changes and warping.
3) lower strength
Paper tubes and cores are not as strong as high-strength metals, fiberglass, or engineering plastics.
4) Dust/Tear
Cutting edges generate dust. Paper can wear or tear over time.
5) Chewing
After prolonged use and high loads, there may be “chewing” on the core end.
6) Opaque
Unless a window is added to the container, customers cannot see the product through the paper tube container.
4. Types of paper tubes
Paper tubes and related products are wound from paper or cardboard. The paper tube or core can consist of one, two, or more layers of brown kraft paper or cardboard.
The innermost layer or layer, lining and outermost layer, and wrapper can consist of different materials (foils, films, etc.) or special papers. Specialized papers and materials can provide water resistance, graphics or labels, or specific colors.
The two main types of paper tubes include spiral-wound paper tubes and convoluted or parallel-wound paper tubes.
- Convolutedly wound tubing is used in applications requiring high flexural strength, compressive resistance, and dynamic strength.
- The paper layers or plies of the helically wound tube are wound at an angle to the tube axis. In a convoluted tube, the outside two edges of the tape are either parallel or at a 90-degree angle to the axis of the tube.
Tubes with thinner walls are widely used as containers or packaging.
Paper cores are essentially tubes of thick wallpaper. Thicker core walls make it possible to wind rolls or sheets of flexible material into rolls during converting operations.
Paper machines produce very large paper rolls (also known as machine rolls, jumbo rolls, reels, or parent rolls) that are rotary cut or converted into many more paper rolls on a winder with a cardboard core. Narrow smaller rolls. Similar large rolls are converted into plastic film, foil, textile, and coated abrasive plants.
You’d be surprised to know that not all paper tubes are suitable for packaging applications. The paper core can be a machine element. Paper cores used in paper mills or plastic film production plants for winding large rolls are mechanical elements that require extremely strong cores that often curl up.
Paper core or small diameter width rolls of tape, labels, foil, paper, tissue, or plastic film for retail packaging and dispensing of products which may consist of thinner spiral wound cores.
The paper tube material is rotated or sawn into paper or composite cans, shipping tubes, push tubes, pyrotechnic tubes, display poles, conversion cores, concrete pile forms, and other paper tube products.
Large fiber or composite tubs and even paper straws are made in a similar winding process. Convoluted winders are often used to make composite drums, a more environmentally friendly alternative to steel drums. Paper straws are wound spirally at a very high speed.
5. Shapes of paper tube
You will find that most paper tubes are cylindrical or round in 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 specifically fit tubes to part or product shapes while eliminating wasted space and additional spacers or packaging material.
With a conical mandrel, paper tubes or cones are wound. Paper tubes are used as yarn guides in the textile industry.
For some applications, you may wish to have your paper tube slit or cut 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 may find it easier to cover a paper or steel roll with a half shell than to slide the roll into a large protective paper tube.
6. How are different paper tubes made?
A paper tube consists of layers of paper or cardboard wound together to form a strong hollow shape, usually cylindrical. These paper layers are laminated or glued together with an adhesive. Tube wall thickness can vary depending on the number of layers wrapped during fabrication. Let me take a look at how different types of paper tubes are made.
1) Paper tube manufacturing
Tube making is a paper-converting process that combines the steps of web slitting, web winding, and lamination or adhesive bonding. A rigid, high-strength tube or fiber core is formed by laminating several layers or layers of paper or paperboard together around a steel mandrel by winding or spinning one or more paper webs or tapes multiple times around a steel mandrel.
In general, layers are usually about 2 to 10 inches (50 to 250 mm) wide, but in some layers, they can be as wide as 20 inches (500 mm). Laminate thickness is typically about 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.
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 in a single thicker papermaking process, or by gluing or laminating several layers of paper together, so some paper tubes can be made from the laminate or laminate composition.
Depending on the specific shape desired for the finished product (round, square, conical, etc.), the paper tube manufacturing process can include winding, folding, and bending.
2) Manufacture of spiral paper tube
During spiral paper tube manufacturing, large rolls of paper, cardboard, and liner material are converted into narrower-width ribbons in a rotary slitting operation. The paper tape is rewound into narrow rolls on the rewind frame.
Rolls of narrow paper tape are piled up in what appear to be huge piles of “poker chips”. “Poker chips” stacks or rolls of paper tape are transported and loaded into the tube-making machine.
Narrow paper webs or webs from several different rolls pass through guide rails and are attached, glued, or taped to a steel mandrel in an overlapping fashion or with spaces between the leading edges of the web. Festoons or spacing allow the ribbon to be fed without interference between ribbons.
By connecting the leading edge or end of the ribbon to the axis of the mandrel obliquely or at an angle of fewer than 90 degrees, the result is the formation of a helix 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 paper or cardboard strip thickness, the adhesive thickness, and the number of strips 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 webs, cloth, vulcanized fibers, and plastic films, various web coaters can apply adhesives to 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
It is fascinating how the paper tube tape is wound in a helical shape to continuously form the paper tube layers and glue them together. The flexible tape wraps around and applies pressure to the paper layers, ensuring proper bond formation between the paper tapes. The fabric-reinforced rubber band also advances the tube along the mandrel.
The stress and performance requirements placed on paper tube forming belts are enormous. These belts are looped or seamless to prevent marking. Their high tensile strength, high friction, and ease of cleaning make them ideal for gripping and moving tubes.
Next, as additional layers of paper are 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 to length using a rotary blade slicing or off-line sawing operation. Depending on the end use, additional deburring of the pipe end edges may be performed.
Another interesting aspect of the tube manufacturing process is the ability to manufacture a large number of highly customized tube products or combinations of materials by using different material layers.
Use a lining or backing layer on the inner diameter (first band) or outer diameter (last band) of the pipe to improve water, moisture, or grease resistance. Linings can consist of sheet metal, foil, coated paper (wax, silicone, or plastic), plastic film, and other protective materials.
3) Manufacture of rotary paper tube
During parallel or convoluted paper tube or core manufacturing, large rolls of paper, cardboard, and liner material are converted in a slitting operation into the very narrow-width ribbons used in spiral tube manufacturing. 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.
External metal rollers can apply pressure in place of the belt, squeezing out any voids or air pockets, providing better adhesive contact and thus enhancing the bond between the paper layers. Due to the wider paper web, higher pressure and tension can be applied during convoluted winding. The higher pressure and tension in the manufacture of convoluted paper tubes results in higher strength for the tubes compared to helically wound tubes.
The higher beam strength of wound paper cores compared to spiral wound cores makes wound paper cores ideal for use in web manufacturing and conversion. The convoluted tube process is used to form high-strength, heavy-duty cores for winding and unwinding large jumbo flexible rolls such as:
- paper and cardboard
- Coated Abrasives
- Plastic film and rubber sheet
- Woven and Nonwoven
- Sheet Metal and Foil
- Carpets and Floors
When thinking about a paper core, we need to think of it 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 lighter applications such as packaging and dispensing smaller width and diameter rolls of labels, tape, foil, tissue, paper, or plastic film.
4) Convoluted and spiral tube joint manufacturing
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 patented paper tube manufacturing process
You use paper cores and related products every day in your everyday life without ever realizing it. Paper towels, facial tissues, aluminum foil, and plastic wrap are wrapped around paper tubes for easy access. If you open up your kitchen cabinets, you’ll see a variety of paper cans, composite cans, and other paper tube containers. Fiber buckets, straw making, and paper cups are all made using similar techniques.
Fiber barrel machines, straw machines, paper cup machines, and composite can machines use similar technology to paper tube winding machines.
Furthermore, paper tube manufacturers and machinery OEMs have proprietary and patented processes for making paper tubes. These specialized processes are used to form tubes and cores with increased strength, reduced weight, or other unique properties and functions.
7. How is the paper tube measured?
Inside diameter is often abbreviated as “ID”. It can be measured with a ruler, but for more accurate measurements, tools called calipers or micrometers should be used. A tube’s ID is measured from the inside of one side to the inside of the other side. Remember to only measure the inside of the hole.
8. Application of paper tube
A variety of industries use paper tubes for several different end uses, including:
1) Containers and packaging
Containers and packaging are probably the largest application areas for paper tubes. Mailing or shipping tubes are used for packaging large documents with folds such as maps, posters, artwork prints, original paintings, blueprints or engineering drawings, and architectural plans.
The powder hose is designed to hold dry and granular materials. Powder tubes often have rotary shakers or sieve tops for easy dispensing, such as disposable salt and pepper shakers.
Frozen lemonade and cookie dough are packaged in food-grade paper tube jars that have liners and airtight ends to hold food safely. Telescopic tubes are often used to package wine bottles, perfumes, cosmetics, etc.
The push-up tube with oil-resistant lining can be used to dispense lipstick, grease, caulk, adhesives, deodorants, and repair compounds.
Chemicals, raw materials, pesticides, fertilizers, etc. can be lined with plastic bags first and packed in paper tube cans and composite drums.
2) Molding and construction
Another interesting application is the use of paper tubes in architecture. Large-diameter helically wound paper tubes are used to form concrete piles. Pour concrete into pipes that may contain rebar. Paper spacer 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.
3) 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.
Specialized dielectric crepe or kraft papers are available for the production of electrically insulating or dielectric paper tubes. Engineered papers and engineered-filled resins are saturated to provide thermal conductivity or insulation.
4) Protection and masking
Spindles, bolt threads, polished shafts, spindles, end mill teeth, plug gauges, drill bits, and other mechanical parts are protected with paper tubes. A protective tube on the spindle or bolt threads prevents impact with other metal parts from chipping or deforming the threads. Paper tube masks slide on threads or shafts to allow selective application of coatings or adhesives where masked areas are left uncoated.
5) Spacing and support
Stores and exhibits use paper tubes as display poles. Paper tube spacers are used inside 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 are also used as reinforcement for corner posts and support within some packages.
6) Winding/Carrying
Paper cores, paper cones, and paper reels are widely used in winding, carrying, and dispensing coils or rolls of wires, cables, pipes, foils, yarns, ropes, etc. Paper spools consist of a paper core and two chipboard paper flanges. Agriculture even uses paper cores to roll turf.
9. Recycling and sustainability of paper tube
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.
Paper tube and core manufacturing is a very environmentally friendly and sustainable process for the following reasons:
1) Sustainable and renewable raw materials
Paper and cardboard are derived from wood, cellulose, and plant-based materials that can be sustainably harvested and replanted.
2) Recycling of waste and customer waste
Manufacturing waste and discarded cores, tubes, paper, and board are sent back to the mill and recycled, reducing the consumption of virgin pulp.
3) Collection and reuse plan
Many paper tube manufacturers have tube and core collection and recycling programs to facilitate the collection of used cores from their customers and waste paper and cardboard from their communities.
4) 100% recycled
Many manufacturers of paper tubes and cores use 100% recycled materials made from discarded cores, tubes, paper, and cardboard.
5) Reduce greenhouse gases
When paper tube packaging replaces plastic and metal packaging, fewer greenhouse gases should be emitted into the atmosphere. While paper processing produces some greenhouse gases, metal and plastic production produces far more. In addition, tree growth and forestry management help capture greenhouse gases.
6) Biodegradability
The paper tubes and cores are biodegradable, so any waste or used tubes that bypass recycling and end up in landfills will break down without harming the environment.
7) Natural/ecologically safe materials
The paper tubes and cores are made from natural plant material and are ecologically safe as they do not contain any toxic chemicals or heavy metals. Paper tubes buried in the ground will compost within 1 to 2 months and add nutrients back to the soil.
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