Uniform Pressing Mechanism in Large-Area Roll-to-Roll Nanoimprint Lithography Process

We aimed to increase the processing area of the roll-to-roll (R2R) nanoimprint lithography (NIL) process for high productivity, using a long roller. It is common for a long roller to have bending deformation, geometric errors and misalignment. This causes the non-uniformity of contact pressure between the rollers, which leads to defects such as non-uniform patterning. The non-uniformity of the contact pressure of the conventional R2R NIL system was investigated through finite element (FE) analysis and experiments in the conventional system. To solve the problem, a new large-area R2R NIL uniform pressing system with five multi-backup rollers was proposed and manufactured instead of the conventional system. As a preliminary experiment, the possibility of uniform contact pressure was confirmed by using only the pressure at both ends and one backup roller in the center. A more even contact pressure was achieved by using all five backup rollers and applying an appropriate pushing force to each backup roller. Machine learning techniques were applied to find the optimal combination of the pushing forces. In the conventional pressing process, it was confirmed that pressure deviation of the contact area occurred at a level of 44%; when the improved system was applied, pressure deviation dropped to 5%.

Bending of sheets and profiles on a four-roll machine for rocket bodies, pipe and frame products. Part 7

The theory and calculation of the parameters of the strain-stress state at the stages of pre-bending, calibration, straightening, bending of a straightened section and bending of the subsequent sections, taking into account the hardening of the billet on a roller machine, is developed. Deformations, stresses and forces acting on the billet from the rolls were investigated by CAD/CAE-modeling. Criteria for the formation of cracks, low accuracy and excessive springback of the part after these stages of processing are determined. Recommendations for the elimination of these defects are given. Keywords: sheet stamping, billet, bending, roller machine, pre-bending, calibration, straightening, CAD/CAE modeling. [email protected]

DETERMINISTIC MODEL OF THE DYNAMICS STRAIGHTENING OF FIBRES DURING CARDING ON A ROLLER MACHINE

The article proposes a simple nonlinear deterministic model of the dynamics of fibre straightening in the working areas “drum – drum”, “drum – roller”, “roller – roller”. The model allows you to predict the value of the average straightness of the fibers in the mass that repeatedly passes through the working area of the machine. The model includes only one parameter that determines the efficiency of fibre straightening during carding. The dependence of the average straightness of the fibres on the number of repeated passes of the fibre through the working area at different values of the carding efficiency is obtained.

Bending of sheets and profiles on a four-roll machine for rocket bodies, tubular and frame products. Part 6

The theory and calculation of the parameters of the strain-stress state at the stages of pre-bending, calibration, straightening, bending of a straightened section and bending of the next section, taking into account the hardening of the workpiece on a roller machine, is developed. Deformations, stresses and forces acting on the workpiece from the rolls were investigated by CAD/CAE-modeling. Criteria for the formation of cracks, low accuracy and excessive springback of the workpiece after these stages of processing are determined. Recommendations for eliminating these defects are given. Keywords: sheet stamping, billet, bending, roller machine, pre-bending, calibration, straightening, CAD/CAEmodeling. [email protected]

STATISTICAL SIMULATION OF FIBRE STRAIGHTENING DYNAMICS IN CARDING ON ROLLER MACHINE

The article analyses the straightening of fibres in the working areas of roller carding machines. The initial assumptions and parameters are given, which were used to develop a computer model for statistical simulation of the process, taking into account the elastic-viscous properties of fibres and their interaction with neighbouring fibres, based on the methods of statistical dynamics. The dynamics of changes in the straightening of the fibres depending on their initial straightening and the number of passes of the fibres through the working zones are studied. It is established that the partial restoration of the tortuosity of the fibres due to their elasticity does not allow for their complete straightening, regardless of the number of repeated passes of the working areas of the machine.

MODERNIZATION OF THE ROLLED GIN REGENATION SECTION

Methods for improving the area of regeneration of roller gin in the process of processing long-staple cotton have been studied. At present, in the process of processing long-staple cotton of the selection variety Surkhan-9 in the regeneration section of the DV-1M roller machine, the choice of cell sizes for removing exfoliated seeds from the fiber is being studied and substantiated by experimental methods.Keywords: long fiber, roll gin, regeneration, variety, pile drum, mesh, fixed blade, forging drum, grill

STUDY OF THE EFFICIENCY OF SQUEEZING MOISTURE-SATURATED PRODUCTS

The leather industry includes many technological machines; a squeezing roller machine is used in many operations, for example, in squeezing, degreasing, and after drum dyeing of a semi-finished leather product. The paper presents the results of experimental studies obtained by determining the influence of multilayer wet leather semi-finished products with monshons under squeezing on the amount of the moisture extracted. Mathematical dependences of the amount of the moisture extracted, for each layer of a five-layer wet leather semi-finished product on the feed rate between the squeeze rollers and the roller pressure were obtained. Experimental research is of scientific and practical importance for the development of a technological process for extracting moisture from wet leather semi-finished products used in the tannery, since the quality of the extraction affects the quality of subsequent technological operations, such as leather shaping and splitting. An experimental study was performed using the method of mathematical statistics, namely, the method of mathematical planning of the experiment. Mathematical models were obtained for the amount of extracted moisture from five wet leather semi-finished products depending on the rate of their simultaneous feed and the pressure of the squeezing rollers. The results of the experiment showed that in squeezing a five-layer product, the productivity of the technological process of extracting moisture from wet leather semi-finished products increases by five times in comparison with existing squeezing roller machines. The use of the results of the experimental study will contribute to a significant reduction in the energy consumption of the squeezing roller machine by simultaneous multi-layer processing of wet leather semi-finished products

Synthesis of a ten-link tooth-lever differential roller transmission mechanism

This article deals with the synthesis of a ten-link tooth-lever differential transmission mechanism. The article contains an analytical review of modern scientific research on the synthesis of tooth-lever differential transmission mechanisms of roller machines with a variable center distance of the working shafts; a method for the synthesis of toothlever differential transmission mechanisms of roller machines with a variable center distance of the working shafts described on the example of a ten-link tooth-lever differential transmission mechanism; the conditions for the synthesis of the mechanism given and substantiated when this mechanism is used in a roller machine; one of its working shafts has the ability to rotate about its own axis, and the second working shaft, in addition to rotation about its own axis, has the ability to move relative to the first working shaft along a line passing through the center the axes of rotation of both working shafts; the geometric synthesis of the tooth and lever contours of the mechanism, the dynamic synthesis of the mechanism, taking into account the angles of pressure between the lever link of the lever contour of the mechanism, which allows us to determine the optimal working position of the mechanism where the angles of pressure are within acceptable limits; the graphs of changes in the angles of pressure between the links of the lever contour of the mechanism, plotted depending on its position.

Development and Testing of a Low-Cost Belt-and-Roller Machine for Spheroid Fruit Sorting

Sorting is one of the most critical factors in the marketing development of fruit and vegetable and should be performed without any damage to the product. This article reports results of the development and testing of a prototype of a low-cost mechanical spherical fruit sorter based on a belt-and-roller device built at the State University of Tabriz, Iran. The efficiency and damage effect of the prototype of the machine was tested at different sorting rates on apples (Red Delicious and Golden Delicious) and oranges. Performance tests indicated that the speed of the feeding belt and transporting belt as well as the spherical coefficient significantly affect the machine’s sizing performance and damages. The results of the test showed a 95.28% and 92.48% accuracy in sorting for Red Delicious and Golden Delicious, respectively, and 94.28% for orange. Furthermore, the machine sorts fruits without any significant damage.