Investigation of the influence of the properties of the pressed material on the energy consumption and design parameters of the oil press

The article presents ways to obtain alternative sources of protein and fat from perennial crops and insects. The main properties of the material influencing the process of extracting fat from insects are considered. According to the results of the studies, the optimal technological parameters of the dried Hermetia illucens larva were revealed when pressing the fat. The optimum mass fraction of moisture is 15%. At a moisture content of insect biomass of 15%, fat filtration occurs at a pressure of 2.5 MPa. Microwave treatment of the material before pressing reduces the pressure at which the fat is squeezed out – 1.9 MPa at a material heating power of 1000 W. The intensity of heating does not significantly affect the acid number of the fat. Therefore, the most optimal heating power is 1000 W. The granulometric composition of the insect biomass also influences the fat squeezing process. Before pressing the fat, it is necessary to grind the larva to the size of particles passing through a 1 mm sieve in an amount of at least 60% of the total mass. The preparation of the material for the squeezing process has a significant effect on the energy consumption of the process. With a granulometric composition of particles of 1 mm, a moisture content of 15% and heating with a microwave power of 1000 W to 60° C, it provides a process that is 2 times less energy-intensive compared to pressing fat from an unprepared material.

Alloys with Shape Memory and Their Physical and Mechanical Properties

The article contains the list of alloys with shape memory and given their structural formulations. As an example, an alloy of nickel and titanium, named Nitinol ({Ni}_3Ti), characterized by the highest shape storage index. Here in the work, the analysis of changes in crystal structure of this alloy is made, at ground temperatures of material heating and cooling.

Printing Parameter Requirements for 3D Printable Geopolymer Materials Prepared from Industrial Side Streams

The objective of this investigation is to study the printing parameter requirements for sustainable 3D printable geopolymer materials. Side streams of the paper, mining, and construction industries were applied as geopolymer raw materials. The effect of printing parameters in terms of buildability, mixability, extrudability, curing, Al-to-Si ratio, and waste materials utilisation on the fresh and hardened state of the materials was studied. The material performance of a fresh geopolymer was measured using setting time and shape stability tests. Standardised test techniques were applied in the testing of the hardened material properties of compressive and flexural strength. The majority of developed suitable 3D printable geopolymers comprised 56–58% recycled material. Heating was used to improve the buildability and setting of the material significantly. A reactive recyclable material content of greater than 20% caused the strength and material workability to decrease. A curing time of 7–28 days increased the compressive strength but decreased the flexural strength. The layers in the test samples exhibited decreased and increased strength, respectively, in compressive and flexural strength tests. Geopolymer development was found to be a compromise between different strength values and recyclable material contents. By focusing on specialised and complex-shape products, 3D printing of geopolymers can compete with traditional manufacturing in limited markets.

TEMPERATURE MEASUREMENT OF POLYMERS UNDER INTERMITTENT HEATING THROUGH USE OF THERMOCOUPLE AND ARDUINO® MICROCONTROLLER

The combination of relatively low production costs and a versatility makepolymers one of the most used classes of engineering materials. Thecomplexity of their chemical bounds, however, make the thermomechanicalprocessing of these materials a challenge since thermal flux frommanufacturing might significantly alter their properties. In this paper wasevaluated the use of thermocouple with Arduino® compatible hardware formeasurement and control of an intermittent heating system for processing ofNylon-6 and polycarbonate thermoplastics. A 2² factorial design was createdfor using K-type thermocouple for the two polymers at two different surfacefinishes obtained by sanding with mesh #80 and #600 abrasives. The resultsindicate that the Arduino interface has satisfactory processing capacity formonitoring heating cycles and temperature logging, making it possible toknow how temperature variated and at what level it stabilized for the heatingconditions presented. The difference in material specific heat capacity andthermal conductivity will affect the observed temperature profile. Roughnessmight present a considerable effect on the material heating since it is linkedto the heat exchange area of the process.

Analysis of Problems in the Heating Temperature Estimation Method by Discoloration of Fire-Damaged Concrete

In this study, a material heating test was carried out and the results were analyzed. Various variables were employed to identify the limitations of the concrete discoloration discrimination method, a method for estimating the heating temperature. The material heating specimens did not use admixture additives, and various design compressive strengths were employed. After the heating experiment, surface color analysis was performed on the cooled specimens to quantitatively analyze the discoloration state of the concrete according to the exposure temperature. As a result, it was judged that the currently used concrete discoloration discrimination method is inadequate for estimating the heating temperature. Moreover, it was confirmed that the development of a new heating temperature estimation method is necessary.

Chemical and morphological changes in fibre structure due to material heating during ultrasonic-assisted embossing of cardboard

Embossing is a commonly used design element on printed products and packaging. It enhances the product impression with optical and haptic effects. The material deformation during the embossing of cardboard is normally done using high mechanical pressure between two dies. The use of ultrasound in the embossing process leads to a noticeable reduction of the embossing pressure and a greater embossing precision. However, there is a noticeable heating of the cardboard during the ultrasonic-assisted embossing process. This work aimed to characterise the effects of heating and to understand the reasons for the greater precision with decreased force when ultrasound is used. Therefore, the effects of the thermal ultrasonic energy on the chemical composition and the morphological properties of the fibres were investigated. The findings showed that no noticeable changes occurred in the chemical composition or fibre geometry as a result of the embossing process with ultrasound.

Flame retardant and durable chloroprene rubber and styrene-butadiene rubber blends crosslinked with copper(I) oxide

The purpose of this work was to investigate the effect of application of copper(I) oxide (Cu2O) as an unconventional crosslinking agent of chloroprene (CR) and styrene-butadiene (SBR) rubber compositions. The use of Cu2O arises from the need to limit the application of ZnO as a CR crosslinking agent. The obtained results indicate that CR/SBR blends crosslinked with Cu2O are characterized by good mechanical properties and a high degree of crosslinking The results show that the proportion of both processing rubbers, as well as the amount of copper(I) oxide, influence the crosslinking of CR/SBR blends and the properties of the vulcanizates. Performing FTIR analysis has allowed the development of a crosslinking mechanism. Crosslinking presumably takes place according to the mechanism of Friedel–Crafts alkylation reaction. Silica, chalk, china clay and nanofiller (montmorillonite modified with quaternary ammonium salt containing hydroxyl groups) were applied as fillers. Among the fillers, silica had the greatest impact on improving the properties. It is arisen from silica activity, unlike other used fillers. The AFM analysis allowed us to determine the miscibility of the rubbers and dispersion of fillers. Thermal analysis was performed to determine the changes occurring as a result of material heating. The low intensity of the peaks corresponding to the crosslinking of the CR/SBR blends may indicate a small amount of bonds formed during heating, or possibility is the formation of connections between chains with a low binding energy. The use of chalk, china clay or silica increases the thermal stability of the vulcanizates. Obtained vulcanizates were characterized by increased incombustibility. The study of combustion time in the air showed that the prepared vulcanizates did not support the burning.

Study of the Processes of High Temperature Material Heating for Plasma Recycling

The processes of high temperature material heating for plasma recycling are investigated. The gas-dynamic parameters of the air-plasma flow in the plasma torch mixing chamber for ecology technologies are determined by methods of mathematical modeling. The characteristic temperatures, velocities and heating times of the utilized gas in different areas of the mixing chamber are determined. The directions of further research and development necessary to create a technology of plasma recycling with maximum efficiency are outlined. The issues of plasma recycling introduction at certain stages of high-temperature technologies are also considered.

Determination of Rational Technological Parameters of Co-Extrusion Processing of Secondary Polymeric Materials by the Method of Physical Modeling

The scientific article presents a physical model of the technical process of co-extrusion processing of secondary polymeric materials. A set of tools for automated control and monitoring of the model is considered, which allows to adjust smoothly the values of the rotational speeds of screws of extruders, the temperatures in the material heating zones and the pressure at the outlet of the co-extrusion head. The results of experiments to determine the temperature of the parison over a cooling time and the effect of screw speed and pressure in the head on the quality of mixing components are given. The results obtained by physical modeling confirm the correctness of the authors' calculations performed using the proposed mathematical models. Thus, it is possible to continue research in this direction, the result of which will be new designs of co-extrusion equipment, allowing to process efficiently polymeric waste into new high-quality products.