ICAR-CIAE- Tobacco Leaves Stringing Machine-trey type

Background:
Tobacco is a commercial crop in India, China, Brazil and other countries because of its high economic value. The primary unit operation of the Flue-Cured Virginia (FCV) tobacco process requires more labour in the stringing leaves. This was observed in significant tobacco growing areas such as A.P and Karnataka for the need of stringing machines on FCV tobacco. Studies indicate that the existing tobacco leaves Stringing mechanism involves one stick consisting of 18-20 bunches, one bunch 2-3 leaves, one leaf weighing 40 requires 15-man days.

Curing the drying process for FCV tobacco leaves, involves crucial transformations such as starch hydrolysis, chlorophyll degradation, achieving a desirable yellow hue, and preserving the flavour, aroma, and overall quality of the tobacco leaves. Traditional curing methods involve stringing of leaves before curing. This process is labour-intensive, painstaking and time-consuming. Thereafter the barn is loaded with these stringed tobacco leaves sticks in different layers on the wooden poles and the flue curing process is done under constant supervision for six consecutive days.

Technology Details:
FCV tobacco leaves stringing machine has been designed. It is a power-operated unit consisting of a sewing and conveyor assembly with a 0.5 HP electric motor, chain, drive, and ratchet mechanism chain stitches to hold the leaves properly and prevent the dropping of even dried leaves. Evaluation of the machine was conducted with two independent variables of different stringing yarn materials (nylon, cotton, specialized yarn, jute yarns- three, two, one ply) and the number of leaves (80, 120, 160, 200-weight of leaves 3-5 kg). The dependent variables were mean stitching time and mean leaf loss/damage after stitching. The chain stitches hold the leaves properly and prevent the dropping of dried leaves in the curing process. Stringing operations take 20 s per stick (4 kg of fresh leaf weight per stick). The stringing capacity is 240 ± 20 kg/h (60 ± 5 no. sticks per hour with leaves loading time 40 ± 5 Seconds) using specialized yarn (viscose material, 34 counts) with an oval-shaped 3 mm needle. It has three loading trays for fast and continuous operations. To make the operation faster and more continuous, it has been provided with three sets of loading trays. 0.5 hp motor was used for both the conveyor and sewing head operation.