scholarly journals IMPROVEMENT OF AUTOMATION SYSTEMS OF THE PROCESS BONDING LUMBER FOR THE LENGTH

Author(s):  
A. Gribanov

Resource conservation and reuse of wood processing waste in a modern market economy is of paramount importance. The technologies and technical equipment considered in the article are devoted to the process of splicing of short wood sections of lumber. The above stages of processing wood waste require optimally designed cutting cards for sawing raw materials in order to obtain the greatest yield of edged sawn timber. The studies of the method of manual cutting of wood defects considered in the article make it possible to determine the time spent on processing furniture blanks sent for subsequent splicing. Significant time is spent on inspection of lumber manually from four sides. The proposed optical method of wood flaw detection allows you to take into account the defects of the workpieces on four sides with the subsequent process of cutting them on the milling unit and automatic gluing along the length. It is proposed to use illuminated cameras, which are installed on four sides of the conveyor, as scanning elements. Photographs from the detectors are combined into a single three-dimensional map of the workpiece using special software and then transmitted in the form of control actions on the end face of the defect cutting line. Waste is automatically removed to the hopper by special pushing machines.

2019 ◽  
pp. 145-154
Author(s):  
Svitlana Ishchuk ◽  
Lyubomyr Sozanskyy

Sufficient supply of woodworking with raw materials while preserving the ecology and rational use of wood is a necessary condition for the functioning of the woodworking industry as one of the key segments of the national economy. The issue is of particular importance given the deepening of world integration processes and the introduction of a moratorium on timber exports from Ukraine. It actualizes the study of the state and dynamics of the formation of raw materials potential of domestic woodworks. The purpose of the article is a structural and dynamic assessment of the economic and environmental aspects of formation of the resource potential of Ukrainian woodworks in comparison with the countries of the European Union, as well as in the regional section by types of wood. In the structure of merchantable wood harvested in Ukraine, fuel wood share increased by 4.3 pp. during 2011-2016, whereas in 2017 it increased by 3.8 pp. compared to 2016 and amounted to 61.4%. Unlike in Ukraine, in the vast majority of EU countries business timber is the basis of the structure of harvested merchantable timber. Thus, in the neighboring countries with similar forest landscape – Poland and the Czech Republic – the share of fuel wood in 2017 was 11.6% and 12.3%, in Slovakia – only 6.3%, and in the EU as a whole – 23. 2%. Hence, the significant deterioration of the structure of the harvested merchantable timber in Ukraine can be interpreted as a threat to environmental, and therefore to national security. On the other hand, the results of the assessments revealed an increase in the volume of commercial timber harvesting in Ukraine (in 18 regions) in 2018, as well as in the level of forest reproduction in the leading regions from the harvesting of merchantable timber (Zhytomyr, Kyiv and Rivne regions) and a decrease in the death rate. The restoration of the logical patterns between the dynamics of the loss of stands and the harvesting of commercial and fuel wood are signs of the beginning of positive tendencies in ensuring the preservation and rationalization of raw potential of domestic woodworks and, at the same time, improving the conditions for deepening the level of wood processing. Further authors’ research in this area will be devoted to the search for effective forms of wood industry development in Ukraine, in particular in the Western region.


2018 ◽  
Vol 222 ◽  
pp. 01013 ◽  
Author(s):  
Katarzyna Pacewicz ◽  
Anna Sobotka ◽  
Łukasz Gołek

Three dimensional printing is a promising new technology to erect construction objects. Around the world in every moment a new prototypes constructions are made by using this method. Three dimensional printing is taken into account as technology which can be used to print constructions in automated way on the Moon or Mars. The raw materials, which can be used with three dimensional printing have to fulfil basic requirements for those which are used in construction. That means that components of printing mortars are made from ingredients easily accessible in area nearby construction site and can be reusable. The cost of printing building objects due to that requirements is comparable to costs of traditional building, which are currently available. However additive techniques of printing needs a dedicated mortars for printer supplying. Characteristic for such mortars is: setting time, compressive strength, followability in the printing system, shape stability of every printed layer, controlling the hydration rate to ensure bonding with the subsequent layer, reusable capabilities, easily accessible raw materials, cost of such mixtures shouldn’t be too high in order to keep 3D printing competitive for traditional ways of building, mortar components should be recyclable and printing process should not influence negatively on an environment and people. All properties of printing mortars are determined by the device for additive application method. In this paper review of available materials used for three dimensional printing technology at construction site is presented. Presented materials were analysed in terms of requirements for building materials technology. Due to the lack of detailed information’s in available literature, regarding to the properties of raw materials, the results of this analysis may be used in the designing of new concrete mixtures for the use in three-dimensional printing technology for construction.


Author(s):  
Irina A. Chetvertneva ◽  
Oleg Kh. Karimov ◽  
Galina A. Teptereva ◽  
Natalia S. Tivas ◽  
Eldar M. Movsumzade ◽  
...  

The paper considers the main components and products of wood processing, agricultural waste, pulp and paper industry waste and qualifies them as sources of pentose-containing resource-renewable domestic raw materials. The article describes in detail the structural components of wood as a natural polymer, which contains aromatic and carbohydrate parts. It is noted that these poly-mers are promising as raw materials for the production of useful chemical products. The role of lignin, cellolose and hemicellulose in the design of mechanical and structural properties of wood is considered. The article considers the features of the sulfonation reactions of the lignin monomer unit depending on the pH of the medium: acidic, neutral and alkaline. There are three main reac-tions that occur simultaneously with lignin in the process of wood delignification during sulfite cooking, such as the sulfonation reaction, the hydrolytic destruction reaction, and the condensation reaction. It is shown that the lignin-hemicellulose matrix contains three types of interconnected mesh structures: the lignin itself; a network of covalent bonds of lignin with hemicelluloses, and a network whose structure is obtained due to the hydrogen bond and the forces of the physical inter-action of lignin and hemicelluloses. The features of chemical transformations of the monomeric aromatic link of lignosulfonate – phenylpropane unit in the processes of wood delignification, the main chemical reactions of wood raw material delignification under the conditions of sulfite and neutral-sulfite brews are shown. The method of quantitative determination of monosaccharides in the composition of the carbohydrate part is proposed.


2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Dendi Prayoga ◽  
. Dirhamsyah ◽  
. Nurhaida

This research aimed to examine the physical and mechanical properties of particle boards based on the composition of raw materials and adhesive content and know the treatment of the composition of raw materials and the best adhesive content and meet the standard JIS A 5908-2003. The research was conducted at Wood Workshop Laboratory, Wood Processing Laboratory Faculty of Forestry,Tanjungpura University and Laboratory of PT. Duta Pertiwi Nusantara Pontianak. The adhesive used is Urea Formaldehyde with 52% Solid Content. Comparison of the composition of rice husks and sengon varies namely rice husk 50%: sengon 50%, rice husk 60%: sengon 40% and rice husk 70%: sengon 30%  and variations in the levels of UF adhesives, namely 14% and 16%, with target density 0,7 gr/cm3. The particleboard was 30 cm x 30 cm x 1 cm Pressing at temperature 140oC for 8 minutes, with  pressure of 25 kg/cm2. The research results of the study of density and moisture content meet the standards JIS A 5908-2003. The best particle values of rice husk and sengon  with composition a ratio of  rice husk 50%: sengon 50% , 16% adhesive content  16%, with density value of  0,7072 gr/cm3, moisture content 9,1949 %, thick development 12,3210 %, water absorption 68,8270 %, MOE 12110,7273 kg/cm2, MOR 161,0025 kg/cm2, firmness sticky 1,9320 kg/cm2, screw holding strength 62,3124 kg.Keywords : adhesive, composition, particle board, rice husk, sengon


2021 ◽  
Vol 87 (4) ◽  
pp. 26-31
Author(s):  
A. N. Fokanov ◽  
V. F. Podurazhnaya ◽  
A. V. Tebyakin

Beryllium products exhibiting a low level of absorption of the radiation energy are widely used in scientific instrumentation design (x-ray technology, radiation detectors, etc.). We present the results of studying the leak tightness of products (disks, plates) made of technical sintered beryllium of standard purity and foil obtained by «warm» rolling from high-purity beryllium. The relevant standards and requirements for testing are given. The leak tightness control was performed using mass spectrometric helium leak detectors with forevacuum backing pumps (oil and dry diaphragm pumps) and specialized vacuum equipment. The parameters of tightness of samples made of technical sintered beryllium were determined. The level of the helium signal during blowing was (0.6 – 7.4) × 10–11 Pa · m3/sec, which corresponds to the tightness standard of foreign analogues and matches the requirements of domestic manufacturers of x-ray equipment. The data spread tended to increase due to the growth of the background value. The obtained results can be used to improve high-tech equipment intended for flaw detection, medical devices, rapid analysis of ore raw materials, radiation safety equipment, etc.


2016 ◽  
Vol 721 ◽  
pp. 154-158
Author(s):  
Edmunds Lodins ◽  
Inga Pudze ◽  
Ineta Rozenstrauha ◽  
Linda Krage

This work focuses on pellets made by Latvian industrial waste (waste cullet glass, sewage sludge, metallurgical slag and alumina scrap metal processing waste and raw mineral materials (limeless clay) to gain high porosity and water sorptiom. Iron sorption using ceramic pellets is explored more detailed. Physical-chemical properties and microstructure were researched to obtain a deeper understanding of how these qualities affect water purification from iron compounds. Three pellets with different properties were made in this paper : B5, A5 and E1. Composition B5 indicates highest iron sorption rate at sintering temperature 1100 °C and shows considerable iron reduction in a solution after one week.


Carbon ◽  
2015 ◽  
Vol 85 ◽  
pp. 194-200 ◽  
Author(s):  
Moo Sung Kim ◽  
Dong Hun Lee ◽  
Chang Hyo Kim ◽  
Yang Jin Lee ◽  
Jun Yeon Hwang ◽  
...  

2020 ◽  
Vol 4 (3) ◽  
pp. 103 ◽  
Author(s):  
Ali Fazli ◽  
Denis Rodrigue

Recycling and recovery of waste tires is a serious environmental problem since vulcanized rubbers require several years to degrade naturally and remain for long periods of time in the environment. This is associated to a complex three dimensional (3D) crosslinked structure and the presence of a high number of different additives inside a tire formulation. Most end-of-life tires are discarded as waste in landfills taking space or incinerated for energy recovery, especially for highly degraded rubber wastes. All these options are no longer acceptable for the environment and circular economy. However, a great deal of progress has been made on the sustainability of waste tires via recycling as this material has high potential being a source of valuable raw materials. Extensive researches were performed on using these end-of-life tires as fillers in civil engineering applications (concrete and asphalt), as well as blending with polymeric matrices (thermoplastics, thermosets or virgin rubber). Several grinding technologies, such as ambient, wet or cryogenic processes, are widely used for downsizing waste tires and converting them into ground tire rubber (GTR) with a larger specific surface area. Here, a focus is made on the use of GTR as a partial replacement in virgin rubber compounds. The paper also presents a review of the possible physical and chemical surface treatments to improve the GTR adhesion and interaction with different matrices, including rubber regeneration processes such as thermomechanical, microwave, ultrasonic and thermochemical producing regenerated tire rubber (RTR). This review also includes a detailed discussion on the effect of GTR/RTR particle size, concentration and crosslinking level on the curing, rheological, mechanical, aging, thermal, dynamic mechanical and swelling properties of rubber compounds. Finally, a conclusion on the current situation is provided with openings for future works.


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