The question of lack of roll method of preparation of flax stems– coupling of stems in an apex and root part of layer is considered. Possibility of diminishing of forces of coupling is experimentally well-proven due to the use of operation of combing.
Key words: fiber flax, flax stem, coupling, combing.
Raising of the problem. During fiber flax harvesting and flax stems preparation by modern technologies there is the considerable worsening of high-quality descriptions of raw material which reduces efficiency of processes of the subsequent processing substantially. Yes, in the layer of stems of flax stems there is such negative phenomenon as coupling of stems — forces co-operations between stems, which are conditioned the morphological structure of plants. Coupling of stems in an apex and root parts of layer has a direct influence on the process of thinning of layer and, accordingly, influences on the subsequent processes of crumpling and scutching. In particular, coupling of stems hinders the satisfactory separation of stems during thinning in a layer-forming machine, as a result — defect, bend, breaking of stems, accumulation, and breaks in a layer.
It results in diminishing of width of layer and increases authenticity of not hit of stems in the transporting conveyer of ribboner which draws a decline the percent of long fibre output. Therefore decline of influence of coupling of stems on the processes of preparation and tooling of layer of stems are important tasks which needs theoretical and experimental study.
Analysis of the last researches and publications. During preparation of layer of fiber flax stems there is the gradual thinning of raw material in a layer-forming machine, by separation of stems by toothed disks with the purpose of diminishing of thickness and mass of layer on unit of length .
For stems separation, it is necessary to attach force of P, which will overcome forces of friction between stems and forces of coupling between them, which are conditioned by their confusing and incurving . Because of that we get, that separation of layer of stems will take place for terms:
where: а — width of a layer;
f — a coefficient of friction of sliding of a stem on a stem;
– an acceleration of the free falling;
l– a length of an area of co-operation of stems;
y — a thickness of layer;
i — anumber of area of co-operation of stems;
– a force of coupling between stems.
The necessity of appendix of force for overcoming of coupling between stems is explained yet that stems in a layer are not only out bowed but also twisted, case bound, contain a bulge and bulges. The values of li in inequality depend on length of stems and their mutual location, which is casual. Thus, the value of li has casual sizes, and as a result forces of coupling between stems also have casual sizes. Consequently, inequality from one side characterizes conformity to law of division of stems in the layer of raw material, and from the second — represents the casual phenomena in this process .
Character of co-operation of stems in the layer dills with the phenomenon of casual location and interlacing of stems at forming of ribbon in a field, rotation of it in the process of aging and forming from a ribbon roll a bale.
Coming from foregoing an important purpose in the process of forming of layer of stems before tooling is diminishing of forces of coupling between stems. To attain this purpose possibly due to a grant a layer of stems, that acts on treatment, additional mechanical actions — combing of apex and root parts of stems [3–4]. Contact of working organ of combing mechanism with the layer of stems will allow to reduce trusts forces of co-operation between stems, and also to give the stems of additional parallelness between them, that also is an important condition during treatment of raw material for the receipt of long fibre.
Aim of investigation. Aquantitative estimation of influence of operation of combing of apex and root parts of stems layer on forces of coupling between stems.
Results of investigation.
Researches of the influence of operation of flax stems layer combing on forces of coupling between stems conducted thinning coming from the features of process. It is known that thinning of layer is made by toothed disks at successive increasing of their speeds and diminished proper teeth and cavities between them, which are accepted to name degrees of thinning. Thus the process of thinning is built so that thinning takes place gradually on each of degrees.
Coming from these reasons an experiment was built as follows (figure1). Handful of flax stems, by mass of two hundred gramme, is approximately divided a conditional line by two equal parts. One of parts was fixed in a clamping device, and the second part, for the lines of conditional division, by the appendix of force, drawn off, issuing thus feet of thinning. Thus, force which was put in order that the division of stems took place, was fixed by a dynamometer.
Fig. 1. The scheme of the experiment
Determinations of force which must be attached for stems selection were conducted in two variants: without combing of flax stems and with the use of combing of apex and root parts of layer. Combing was carried out gradually from the ends of stems to the center by a slat on which the fastened needles were on. A calculation amount of combing is 6 times for each parts of layer. Results are presented on figure 2.
Fig. 2. Force, necessary for separation of stems in a flax stems layer
Information, presented on figure 2, shows that the operation of combing of layer of flax stems violates the coupling of stems and diminishes force which must be attached for stems separation. So for separation of stems in a layer of stems without the use of combing, it is necessary to attach force an average of which is 9,04±0,22 N. At divorcing of stems after combing of apex and root parts of layer, force which is needed for separation of stems diminishes more than in 3 times and evened 2,88±0,17 N.
It is also necessary to note that the operation of combing is very important for the subsequent process of thinning of layer in a layer-forming machine. It is confirmed by data, which are presented in figure 3.
Fig. 3. Quality of stems separation: а — without combing; б — with combing
As we can see at the variant of the research without the use of combing (figure 3-a), valuable division of stems was not made. Coupling between stems in an apex and root parts of layer hinders the stretch of layer, and as a result stems are broken up and bend, forming a ring. Thus there is diminishing of width of the layer.
At the variant of research with the use of combing (figure 3-b), though there is a small bend of separate stems, however layer is divided satisfactorily, and the width of layer remains unchanging. This result proved the meaningfulness of flax stems combing operation during layer forming.
Conclusions. Although forces of coupling between stems are casual sizes, however it is possible to decrease their influence on the process of thinning of layer. By reserve herein the operation of combing can serve exactly. Use of combing is violated coupling between stems, diminishes force, necessary for the division of stems in a layer, that allows to prepare much better and form a layer for tooling.
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