The consumption of cigarettes amounts to a staggering 5.5 trillion annually. Approximately 7.5 million metric tons of tobacco crops harvest to suffice this global demand. Tobacco leaf processing is highly complex. The tobacco leaf undergoes several stages at manufacturing plants to give products like cigarettes, pipes, cigars, and many others. In some parts of the world, people chew tobacco as it is to soak into the unfiltered flavor.
Tobacco processing machines cater to over $1.5billion in annual trade. Germany, Italy, and Hungary rank among the top exporters, while the UAE, Indonesia, and China register as the top importers of tobacco processing machines. Here are some useful tips for tobacco leaf processing.
The role of moisture in tobacco leaf processing
The most critical requirement for effective tobacco leaf processing is maintaining the optimum moisture content. The first step to ensure that is to separate the central stem called midrib from the leaf called the lamina. This is done mechanically at the primary processing plant. An optimum moisture level is important for different steps including threshing, preparing the final products, and giving a quality smoke experience.
Tips for the different stages of tobacco leaf processing
Conditioning the green leaf and stem
When the harvested tobacco arrives at the manufacturing plant, it undergoes a mechanical threshing process. A rotating drum called the conditioning cylinder makes the tobacco leaves pliable using pressurized hot air and steam. Self-controlled steam-jet nozzles force moisture into tobacco as per the requirement. An ideal moisture content lies between 17 to 22%. It is important to measure the moisture content accurately. A mistake here could mean inappropriate moisture content in the leaves, rendering a poor-quality tobacco experience.
The stem of the leaf separated in the earlier stage must have a moisture level of around 40%. This makes the stem more flexible for the cutting process.
How to record accurate moisture reading for effective tobacco leaf processing?
Moisture maintenance requires accurate real-time moisture readings. You can achieve this by installing equipment such as the tobacco moisture sensor either at the entrance or exit of the conditioning cylinder. Moisture sensors having digital output allow optimal moisture maintenance in a closed loop process, giving a desired operational efficiency. The ideal place to position the sensor is about 8 to 10 inches above and away from the conveyor belt. It is to ensure accurate monitoring as the water vapor from the tobacco might temper the readings.
The Threshing Process
Next, the leaves pass through the threshing process. This involves numerous mechanical threshers and pneumatic filters. The cutters in the threshers tear off the lamina from the stem. You get a mixture of the lamina, stems, and unthreshed leaves from the thresher drums. A filter separates the lamina from the unthreshed leaves and the stem from this mixture. Lamina proceeds for further processing. The unthreshed leaves and stems go into the next thresher for separation. This process continues till all the stems and leaves are separated.
The stem proceeds for conditioning to achieve the optimum moisture level which is greater than that of a green leaf. All the stems undergo a process whereby they get a uniform cut, through a stem cutter.
The Drying Process
The drying process helps preserve the shelf life of tobacco products so that they can stay fresh for a long. A moisture level between 11 to 12% of the lamina and stem is ideal for a quality tobacco product. Passing through different threshers and classifiers makes the lamina contain different moisture levels The drying process makes the lamina achieve uniform moisture throughout. This process brings the moisture level down to 6 to 8%. Then, the lamina is set to cool down.
Next, the product moves for humidification. The tobacco absorbs moisture in this chamber to reach the expected balance. This step brings the moisture content up to the desired level of 11 to 12%. The lamina moves to the packaging unit from here. It is stored safely for further use. The stem undergoes a similar drying process.
The final product achieves a shelf life of about six months at least through such a rigorous process. The tobacco, stored in cases, transports around the world.
How to maintain optimum temperature levels at the different processing stages?
Thanks to technological innovations, quality control has become relatively easier. However, it means even the slightest deviation from the standard operational methods cannot go unnoticed by the final consumer. This could mean a loss of reputation for the manufacturer.
Just as moisture sensor installments allow for accurate moisture recording, an integrated temperature sensor can help monitor and regulate the optimum temperature level. A temperature sensor at the drying and conditioning stages can help monitor the processes.