Cutting the tobacco (8) is the main technological process in the preparation of tobacco blends for the manufacture of tobacco products. The purpose of this process is to cut tobacco leaves into bulk pulp with minimal losses in the form of dust particles. The key characteristics of the quality of the bulk pulp are the cut cleanliness and the size of the tobacco fiber, which largely depend on the settings and the quality of the cutting machine. The consistency and stability of the tobacco cutting machine is guaranteed by important elements of the production line: a conveyor belt with a metal detector (6) and a storage device (7).
To minimize dust losses, the optimal moisture content of raw materials is about 20%. The total loss of tobacco throughout the entire technological process of preparing tobacco blends is approximately 6%. Cutting tobacco on a cutting machine allows you to get tobacco fibers with a width of 0.1-0.9 mm. It is at the cutting stage that the settings of the tobacco cutting machine determine the future purpose of blends in terms cigarette formats: king size, queen size, slim size, super slim size or Roll your Own (RYO).
Tobacco drying (9) is an operation necessary to lower the moisture content of tobacco from 20% required for cutting to 13.5% required for the finished product. During the drying process, the tobacco pulp warps under the influence of temperature, the resinous film softens and the adhesion of the fibers decreases. After drying, the volume of tobacco increases, as a result of uneven heating, the fibers that were straight after the machine cutting become twisted. Increasing the temperature for a short time has a positive effect on the smoking properties of the cut tobacco. There is a decrease in nicotine in the tobacco blend and, as a result, the strength goes down to 10%. After the heat treatment, the consumption of tobacco during the manufacture of tobacco products is reduced by 1.2-1.5%. This is due to the improvement of the volumetric-elastic properties thanks to the decrease in fiber bonding and the increase of the filling capacity of the tobacco as a result of twisting during heating. Designs of all kinds of drying devices using different drying methods and, as a result, with different economic costs, are created for the purpose of lowering the moisture content in the tobacco while increasing its volume. So, the percentage of the increase in the volume of the tobacco blend and, as a result, the economic effect on the production depends on the design of the drying device. Also, the cost of blend is influenced by the percentage of cut rolled stems (CRS) or cut rolled expanded stems (CRES) introduced into the recipe through the storage bin (10).
Cooling the tobacco blend in the silo (11) to 25C after the drying step is necessary to prevent the formation of moisture condensation before placing the dried tobacco in the accumulators (tobacco silo) for the cigarette production process. As a result of cooling the cut tobacco, the moisture level is evened out throughout the entire volume of the tobacco mixture.
Aromatization of the tobacco blend (12) takes place in the aromatization drum after adding the expanded stem (CRES) and reconstituted tobacco (Recon). To give the final blend an improved aroma, a low dosage flavoring solution, 0.1 - 0.2% by weight of the tobacco, is evenly applied to the cut tobacco.
The pre-final process of the technological production of a blend is the air separation of the cut raw tobacco (13). Air separation removes fine pieces and tobacco dust. For practical purposes, in production, to assess the quality characteristics of bulk pulp, three types of fractions are distinguished
— coarse fiber, fine particles, dust. The increased percentage of fine particles and dust in the cut fibrous mass of tobacco raw materials indicates its unsatisfactory level of quality. Thanks to a well-established practice of determining the composition of fractions by particle size using the sieving method, we can talk about the heterogeneity of the three main types of fractions and their different physical properties. Coarse fiber - the fraction remaining on a sieve with holes of a 3 mm diameter. Fine particles
— cut tobacco fiber, which passed through a sieve with holes of a 3 mm diameter and remains on a sieve with holes of a 0.5 mm diameter. Dust is a type of fraction that has passed through a sieve with a hole diameter of 0.5 mm.
Long fibers are characterized by poor elasticity, excellent deformation, and a good specific volume. The fine particles are known for excellent flowability, good elasticity, and a low specific volume. The dust has a minimum volume and an almost complete absence of characteristics inherent in bulk fiber mass, as a result of this it adversely affects the taste properties of the tobacco product and technological process. As a result of separation, the tobacco blend for the production of cigarettes takes on its final shape.
The finished product is sent by a conveyor belt to the packing and weighing station (14), where it is packed according to industry standards (C-48 boxes with a polyethylene liner) and prepared for further shipment to the client.
Fourteen production stages give a very general outline of the complex process of producing tobacco blends from tobacco leaves called "Primary processing". The final part of the journey of tobacco to becoming a finished tobacco product packaged in consumer packaging is called "Secondary processing".