Carbon fibre rollers are very light and are, thus, a high performance alternative to steel and aluminium rollers
By: Anuj Bansal*
The brand ‘Carbon Light’ was created to provide to the engineering world products that are becoming necessary for industries to maximise their efficiency, improve quality and reduce power consumption.
‘Carbon Light,’ being a part of the North Street Cooling Towers Pvt. Ltd., has been developed with a set of 29-year old values of utilising the best in technology with the best available raw materials to deliver reliable products in order to establish and retain long-term business relationships with its customers.
Carbon fibre rollers are very light and serve as an optimum high performance alternative to the steel and aluminium rollers which are currently being used in printing, packaging, slitting-winding and other converting processes.
Benefits of carbon fibre rollers
- High specific stiffness.
- Quick response to line speeds.
- Line speed achieved almost instantly.
- Can reduce diameter to reduce air entrainment.
- Higher critical speeds at lower weight.
- Can run wider formats.
- Better precision in load cells: Dancing rollers or every roller installed on load cells, if made of carbon fibre, form a lower tare weight. This means that the actual film tension can be read with greater precision and quickness from smaller load cells.
- Lower starting time: Thanks to the lower inertia, the plant starting time can be overwhelmingly lower with a better efficiency in production.
- Many rollers don’t need to be powered: Often metallic rollers, due to the weight and lightness of the film they carry, need to be powered and controlled by complex electronic systems in order to avoid stretch or damages. The lightness of carbon is such that even a light film traction can move the roller, saving all cost derived by motors, electronic drivers, control systems and energy necessary to power it.
- Reduction of surface contact: Another advantage of smaller diameters comes by reducing, at same angles, the contact area between film and roller. This means there are fewer possibilities to damage the film and less interference during its course.
- Reduction in bearing size which affects friction significantly. Longer service life of bearings.
Carbon fibre rolling element
Carbon fibres are filaments about 5-10 microns in diameter and composed mostly of carbon atoms. Carbon fibres are highly stiff and have high tensile strength, low mass, high chemical resistance, high temperature tolerance, good electrical conductivity and low thermal expansion. After due impregnation with certain resins, they form, what should be called -carbon fibre composites.
Carbon fibre composites (CF composites) have very high strength to mass ratio and are better than steel alloys.
Combined with other properties of CF, this material is definitely a winner against metals used in engineering.
The manufacturing reel-fed machinery is used for converting flimsy plastic films; several rollers are used in the machine for conveying these films. Most of these rollers idle and rotate only due to the friction on their surface due to the wrap of the film. One or more rollers in the machine could be powered by a motor to rotate.
Traditionally, the construction of these rollers is done usingaluminium as they are light in mass, so that the energy required to accelerate (or decelerate) the rollers is low and also so that the tension imparted to the films for conveying them is well within their elastic limits.
One such example is Kalpvrux; being an entity manufacturing reel-fed machinery, Kalpvrux has mastered the technology of managing very low tensions in order to convey the flimsiest of plastic films and accelerating to high speeds in least possible time.
Recently, a ‘Carbon Light’ brand of CF composite rollers has been introduced in Kalpvrux machines.
This has reduced the mass of the roller to one-eighth of the traditional rollers. The effects seen are as follows:
- Dynamic balance: Being low in mass, the residual imbalance is a couple of grams at the most. The time devoted to balance a roller has reduced. This is a very big improvement against the metal roller.
- Energy saving: The CF composite rollers have a very low mass moment of inertia and, therefore, very little energy is required to ramp or brake it. Better acceleration/deceleration times have been clocked.
- Tension: The energy required to rotate a roller could, at times, be excessive for very flimsy films, wherein it could surpass the elastic threshold and therefore elongate the film. With the introduction of CF composite rollers, the profiling of the tension is now absolutely in hand and with good scope of further challenges.
Future of carbon fibre rollers
1. The global market for flexible packaging is forecast to grow at an annual average rate of 3.4 percent over the next 5 years, and is expected to reach $248 billion (€217 billion) by 2020.
2. Flexible packaging is the most economical method to package, preserve and distribute food, beverages, other consumables, pharmaceuticals and other products that need extended shelf life. Earlier, ketchup glass bottles were circulated in the market. Now, most households use the squeeze pack for easy handling.
Flexible packaging uses less resources and energy than other forms of packaging. It provides significant reductions in packaging costs, materials used and transport costs, as well as certain performance advantages over rigid packaging. Use of flexible packaging can minimise package transport costs between the converter, packer/filler, retailer and end user. It not only takes up less space when empty in comparison to rigid packaging, but can also be constructed on the spot from roll materials at the filling location, thereby minimising transportation of ready-formed empty packaging. A key trend for flexible plastic packaging is continued down gauging as the combination of environmental pressures and high polymer prices make customers demand even thinner films.
This down gauging of plastic films will continue even though many of the traditional films are reaching the limits of this trend. The flexible packaging industry will begin to promote more of the ‘pre-cycling’ benefits of these packages versus rigid packaging as the combination of environmental pressures and uncertain polymer prices persist. No declines for paper and aluminium foil are forecast as demand for them reached the bottom line in many regions.
*Technical Manager, Carbon Light