Additive manufacturing (AM) technology refers to the process of producing 3D objects by adding material in successive layers. Fused deposition modeling (FDM) is one of the AM technologies where objects are built by adding layers of melted thermoplastic filament onto the printing surface. Mechanical properties of FDM printed part depend on many influencing factors such as material composition, extruding temperature, printing parameters and environment temperature. The aim of this study was to investigate consistency of mechanical properties of elements produced by FDM additive manufacturing technology. To do so, mechanical tensile and compression tests were conducted on ten samples using polylactic acid (PLA) and ten samples using acrylonitrile butadiene styrene (ABS) thermoplastic material. Tensile tests were conducted using Shimadzu Compact Tabletop Testing Machine EZ-LX and the compression tests were done using VEB ZDM 5/91 testing machine. The ultimate tensile strength, strain, Young modulus and compression yield strength values were analyzed. The ABS thermoplastic material showed greater consistency in mechanical properties during tensile tests. Tensile strength values for PLA material varied between samples thus showing greater inconsistency in repeatability of mechanical properties. Compression tests, on the other hand, showed that PLA samples had greater consistency in mechanical properties compared to ABS samples.

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Original scientific paper This paper presents experimental usage of updated control methods such as thermovision and spectrophotometric analysis in graphic industry. These methods were applied to research the influence of ink volume and material characteristics on colour and heat treated printed substrates. Samples used in these experiments were printed by digital ink jet printing technique using Mimaki JV22 printing machine and J-Eco Subly Nano inks. As printing substrates, three different types of materials were used. Materials were different in respect of fabric weight and thread count, while material composition was the same for all three materials. The appropriate test card consisting of fields of CMYK colours was printed, varying the number of ink layers applied. Samples were exposed to heat treatment after printing. The heat applied was measured by thermovision camera. Spectrophotometric measurements were conducted before and after heat treatment. Based on data gathered by spectrophotometric measurements colour difference ΔE76 was calculated. Results showed that increasing number of layers, as well as right choice of substrates, can improve behaviour of printed product during exploitation. Keywords: digital textile printing; heat treatment; ink layers; material characteristics Termovizijska i spektrofotometrijska analiza diferenciranog nanosa boja na specifične podloge izložene toplinskim opterećenjimaIzvorni znanstveni članak U radu su predstavljene primjene suvremenih metoda kontrole, kao što su termovizijska i spektrofotometrijska analiza, u grafičkoj industriji. Suvremene metode kontrole primijenjene su pri istraživanju parametara diferenciranog nanosa boje na specifične podloge izložene toplotnim opterećenjima. Uzorci koji su rabljeni za istraživanje odštampani su Ink jet postupkom na digitalnom tiskarskom stroju Mimaki JV 22 koja koristi J-Eco Subly nano boje. U procesu tiska, rabljene su tri vrste podloga, pri čemu je za sve njih sastav materijala bio isti, ali su se razlikovale prema parametrima površinske mase i gustoće pletenja. Odgovarajuća test karta koja se sastojala od polja CMYK otiskana je s pet različitih nanosa boje. Ti uzorci su izloženi toplinskom djelovanju, pri čemu je polje toplinskog djelovanja mjereno termovizijskom kamerom. Uzorci su analizirani spektrofotometrijskim mjerenjima prije i poslije toplinskog djelovanja te je na osnovu tih podataka određena vrijednost razlike boje (ΔE76). Dobiveni rezultati su pokazali da povećanje broja nanosa boje, kao i odabir odgovarajuće podloge za štampu, može povećati eksploatacijske karakteristike otisaka.

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Manufacturing of the embossing tools customary implies use of metals such as zinc, magnesium, copper, and brass. In the case of short run lengths, a conventional manufacturing process and the material itself represent a significant cost, not only in the terms of material costs and the need for using complex technological systems which are necessary for their production, but also in the terms of the production time. Alternatively, 3D printing can be used for manufacturing similar embossing tools with major savings in production time and costs. However, due to properties of materials used in the 3D printing technology, expected results of embossing by 3D printed tools cannot be identical to metal ones. This problem is emphasized in the case of long run lengths and high accuracy requirement for embossed elements. The objective of this paper is primarily focused on investigating the influence of the printing speed on reproduction quality of the embossing tools printed with FDM (Fused Deposition Modelling) technology. The obtained results confirmed that printing speed as a process parameter affects the reproduction quality of the embossing tools printed with FDM technology: in the case of deposition rate of 90 mm/s was noted the poorest dimensional accuracy in relation to the 3D model, which is more emphasised in case of circular and square elements. Elements printed with the highest printing speed have a greater dimensional accuracy, but with evident cracks on the surface.

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The color of textile products is mainly controlled during the material production process, e.g. dyeing or printing, using color management protocols. Little attention has been given to researching the color appearance of the textile material applied to final products, where textile material is applied to a shape. The results are reported of research into the color appearance of textile materials of varying material characteristics, color, and geometrical shape to which they are applied. The main focus was on determining color differences between real textile material color and the perceived one. Materials were characterized by their composition, fabric structure, fiber type, thread count, surface characteristics, and glossiness. Samples of red, blue, orange, violet, and green color were chosen as the most frequently used colors in real application. Textile materials were applied on three differently shaped objects (flat surface, cube, and cylinder). The object color was determined by objective instrumental measurements as well as subjective judgment. A specially constructed light chamber was used to ensure constant experimental conditions. Data were subjected to statistical analysis in order to determine differences of each CIE Lch color coordinate. Results indicate significant effects of objects shape on color appearance.

In today’s increasingly competitive market environment, new packaging must meet more requirements than before to meet customer expectations. The packaging must meet not only functional and aesthetic requirements but also ergonomic requirements to ensure satisfying user experience. An important issue in ergonomic design is the identification of factors that lead to user comfort and discomfort. The packaging is a product that undergoes manual manipulation and given the various forms of packaging and it's opening and closing systems, they require using different grip types and movements. Using packaging that is not well designed can cause intense physical exertion and frustration for users. The subject of this paper is a review of methodologies for assessing the ergonomics of packaging products. Methodologies for evaluating the ergonomic characteristics of packaging provide a proposal for structuring the investigation. Also, it gives a proposal for the proper prioritization of a packaging problem that should be identified as the most dangerous risks for physical injuries or for causing stressful situations to users. First, it is necessary to gain a clear insight into how the users handle the packaging in order to create knowledge and a clear idea of what is useful or harmful in the existing packaging design and to find the potential for its improvement. There are various methods for studying, analyzing and evaluating user experience while using a packaging. Combining such methods with knowledge of the anatomical structure of the body and how it reacts to the load enables the creation of efficient and ergonomically designed packaging. This paper will present methodologies and guidelines for assessing and improving the ergonomic qualities of packaging. The aim of this paper is to define the key factors and most relevant methodologies for conducting successful ergonomic research.