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The paper describes the influence of the drum system construction of two modern carding machines on the porous structure of spunlace non-wovens composed of polyester and viscose. The non-woven fabric structure, including the number and size of the pores, determines the tensile strength of the composites obtained. The spunlace non-wovens were subjected to tensile strength tests in the machine, and cross-directions and microscopic observations of their structure were made. The results of the experiments were used to determine the relationship between the strength of the material and the porosity of its structure. This knowledge was used to prepare recommendations for the manufacturer of wet wipes in order to enable the selection of a carding machine for the mass production of final products with strength properties that meet market requirements and satisfy the end customer. [ABSTRACT FROM AUTHOR]

This paper presents a new approach for searching the most favourable mechanical assembly sequence. The proposed method is described and its basic modules are presented. The concept is based on the assumption that the method should help the engineer in specifying the best assembly sequence with the short possible time calculation, taking into account the principles of design for assembly at an early stage of development of the product design. The algorithm for generating an accurate assembly sequence was described in detail and its application on real-life example was presented. [ABSTRACT FROM AUTHOR]

This article presents the issue of recycling and maintaining the processing properties of materials made of plastics. For this purpose, samples from recycled, low-density, polyethylene were tested. The impact of the use of dyes and surface printing on the lifecycles of material and its quality was examined. For this purpose, an analysis was carried out using differential scanning calorimetry and thermos-gravimetry. It was found that the use of dyes may affect the quality of the material and increase the disposal costs of pre-used materials. [ABSTRACT FROM AUTHOR]

This article presents an analysis of the images of the fibres produced in Spunlace technology, using two different types of modern cards, i.e. using a single card, then using the other card, singly, and finally, using the two cards in parallel. The fibre images were analysed for the presence and orientation of free spaces between carded and water-spiked fibres of viscose and polyester. The longitudinal and transverse strength of the fibres produced, was tested. On this basis, the correlations between the construction of the cards, the method of mixing the fibres and the strength of the non-woven fabric were determined. The research presented in the article could prove to be a useful source of information for carding machine manufacturers; moreover, it could be used by carder users, in order to improve the textile production process. [ABSTRACT FROM AUTHOR]

This article describes the studies of the mechanical properties of the martensitic structure of C45 steel, obtained as a result of heat treatment. This steel was subjected to high tempering, within the temperature range of 500÷700°C (every 50°C) and for various exposure times, from 15 minutes to 23 hours. Moreover, martensitic steel was subjected to tests by quenching at a temperature of 850°C for 20 minutes and then tempering it for 1 hour, within the temperature range of 50÷800°C (every 50°C). The resulting steel samples were subjected to strength tests, that is, to tensile and hardness tests and also to tests on the micro-structure. The results of these studies are presented and discussed, in detail, in terms of their practical application. [ABSTRACT FROM AUTHOR]

The production of high-quality nonwovens, composed of polyester and viscose, depends to a large extent on the carding process of both components. Due to the complexity of the operations carried out, in the mixing, unifying and stretching of the raw materials, this process is one of the most important and is carried out on machines called carding machines. Today, carding machines are manufactured by many manufacturers and their complexity is increasing. In this article, two modern carding machines, consisting of two main drums coupled to five carding-doffer assemblies, but differing in the transmission of the fibre deck between the main drums and the mechanical performance of the operation, were submitted for comparative analysis. To this end, mathematical models of the carding process were developed and the stabilisation and delay times of the fibres in the carding process were determined; the absorption coefficients between each pair of co-working drum pairs in the carding analyses were also determined. On this basis, numerical simulations were conducted and are presented and discussed here. [ABSTRACT FROM AUTHOR]

The production of Spunlace nonwoven fabric is a complex process and includes, among other things, several important stages, such as carding, needling and drying. One of the most important stages is the carding process, which has a significant impact on the shaping of the physico-mechanical and qualitative characteristics of the nonwoven fabric. The article presents the modelling of the carding process in a two-drum system. A mathematical model, determining the expected number of drum and carding card cycles was proposed. Based on this model, delays were determined, due to longitudinal shifts of fibre in the carding process. Numerical simulations have been made and discussed in relation to fibre collection factors, at different production speeds and the number of carding rollers in the worker-stripper system. [ABSTRACT FROM AUTHOR]

The production of nonwoven fabric dedicated to the hygiene sector of industry is a dynamically developing market segment. Competition among manufacturers forces high performance in the economic production of nonwoven fabric with appropriate physical–mechanical parameters. One of the most important processes which guarantees that such characteristics may be obtained in the production of nonwoven fabrics, is the carding process. The article presents the modelling of the carding process on a modern, double-drum carder. The dynamics of the formation of nonwoven slivers was analysed, taking into account the homogeneity of the density of the fleece formed. In the description of carding dynamics, the mass balance of fibres was taken into account. Numerical simulations concerning the gradual increase in fibre accumulation, over time – and in relation to the fibre collection factor and the number of rollers in the worker–stripper systems – are presented. [ABSTRACT FROM AUTHOR]

The issue of rubber waste management, among others, due to the intensively developing branch of road transport, and hence a large number of manufactured car tyres, is particularly important for the sustainable development paradigm. Tyres are used not only in internal combustion cars, but also in electric cars, which are considered more ecological. Worn car tyres are not the only type of rubber waste; however, due to the scale of production, they occur most often. The article discusses laws related to this group of waste and methods of its recovery and recycling. All discussed methods of disposal of rubber waste have been characterised in terms of their advantages and disadvantages. An innovative, newly designed pyrolytic installation has also been discussed. [ABSTRACT FROM AUTHOR]

This paper presents the assumptions of a thermodynamic equation of state for polymers according to the Renner model. The experiments involved extruding a biocomposite based on poly(butylene succinate) that was filled with ground wheat bran with its size not exceeding 200 μm. The biocomposite was produced in pellet form with three different contents by weight of wheat bran, i.e., 10%, 30% and 50%. All specimens were examined for their thermodynamic p-v-T characteristics. Taking advantage of the SimFit module of Cadmould 3D-F, experimental results were used to determine the coefficients of thermodynamic equation of state for the tested biocomposite according to the Renner model. The coefficients were then used to calculate transition temperature and to create diagrams illustrating the relationship between pressure, temperature and specific volume for the tested biocomposite. The obtained results can serve as a basis for assessing the suitability of the biocomposite for injection molding, selecting technological parameters of this process, as well as for analyzing shrinkage and defects of injection-molded parts. [ABSTRACT FROM AUTHOR]