Justification of operating modes for pneumothermal mobile equipment for separation of Scots pine needles

The growing demand for natural textile materials is driving the search for fundamentally new raw materials for the production of textile fibres, in particular the use of pine needles for the production of textile fibres. The development of a technology for processing Scots pine needles at logging sites using a pneumothermal method with the help of a mobile equipment for separating pine needles requires research in order to substantiate its operating principles. In particular, it is necessary to substantiate the temperature and duration of drying and the amount of vacuum for the pine needle drying process. The use of pine needles, which represent up to 30% of the mass of the crown of a Scots pine, is an important factor in their processing and thus a more complete use of forest resources. Industrial processing of pine crowns requires the separation of needles from wood and bark, which are harmful impurities during the production of textile fibre. Experimental studies were carried out on branches with pine needles. The dimensions of the pine needles were determined and the minimum needle removal force that could be achieved in the drying chamber of the mobile equipment was determined. A two-factor experiment was used to determine the equation of the pine needle removal force on temperature and drying time. The minimum pull-off force was compared with the pull-off forces at different temperatures and drying times. As a result of the studies carried out to justify the operating modes of the mobile equipment for the pine needle separation, the parameters of the drying process have been established: drying temperature 80°C, drying time 90 minutes. Further research is required to establish the level of vacuum in the drying chamber of the mobile equipment, and to determine the dependence of the pine needle removal force on the temperature and drying time in other ranges of variation of these parameters.