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The usage of additive manufacturing (AM) technology in industries has reached up to 50 per cent as prototype or end-product. However, for AM products to be directly used as final products, AM product should be produced through advanced quality control process, which has a capability to be able to prove and reach their desire repeatability, reproducibility, reliability and preciseness. Therefore, there is a need to review quality-related research in terms of AM technology and guide AM industry in the future direction of AM development.

This paper overviews research progress regarding the QC in AM technology. The focus of the study is on manufacturing quality issues and needs that are to be developed and optimized, and further suggests ideas and directions toward the quality improvement for future AM technology. This paper is organized as follows. Section 2 starts by conducting a comprehensive review of the literature studies on progress of quality control, issues and challenges regarding quality improvement in seven different AM techniques. Next, Section 3 provides classification of the research findings, and lastly, Section 4 discusses the challenges and future trends.

This paper presents a review on quality control in seven different techniques in AM technology and provides detailed discussions in each quality process stage. Most of the AM techniques have a trend using in-situ sensors and cameras to acquire process data for real-time monitoring and quality analysis. Procedures such as extrusion-based processes (EBP) have further advanced in data analytics and predictive algorithms-based research regarding mechanical properties and optimal printing parameters. Moreover, compared to others, the material jetting progresses technique has advanced in a system integrated with closed-feedback loop, machine vision and image processing to minimize quality issues during printing process.

This paper is limited to reviewing of only seven techniques of AM technology, which includes photopolymer vat processes, material jetting processes, binder jetting processes, extrusion-based processes, powder bed fusion processes, directed energy deposition processes and sheet lamination processes. This paper would impact on the improvement of quality control in AM industries such as industrial, automotive, medical, aerospace and military production.

Additive manufacturing technology, in terms of quality control has yet to be reviewed.

This paper aims to study the effects of solid additives and compounding processes on the selective laser sintering (SLS) behavior of composite powders.

Composite powders were prepared from TrueForm™ acrylic‐styrene co‐polymer and SiO₂ powder. Dry mixing and melt extrusion were used as the blending processes to produce the composite powders. Some SiO₂ powder was ground and treated with silane coupling agent before blending to study the effects of particle size and surface treatment of the filler, respectively. The temperature of the powder bed was monitored using an infrared thermometer. The fusion behaviors of the powders were investigated in situ using an optical microscope and the sintered specimens were examined by scanning electron microscopy.

For a given volume fraction of the filler, reducing its particle size will hinder fusion between the polymer particles and weaken the sintered specimens. Surface treatment of the filler by silane coupling agent had little effect on the morphology of the sintered specimens; however, it slightly improved their strength. The blending method plays an important role in the sintering behavior of the composite powders. Although melt blending improved the polymer‐to‐polymer contact between the composite powder particles, the high‐resultant viscosity of the material adversely affected the densification of the powder bed, leading to a highly porous structure of the sintered specimens.

The sintering experiments were conducted in ambient conditions using a laser engraving machine instead of a commercial SLS machine with atmospheric control. The temperature gradient within the powder bed was expected to be higher than that in normal SLS processes.

The SLS behavior of a composite powder not only depends on its composition but also on the powder preparation method or powder morphology.

This paper provides some useful information for future development of composite powders for SLS applications.

The purpose of this paper is to present the results of interaction occurring during the exposition of some specific carbon textile materials obtained in laboratory conditions to beams of various laser types.

Carbon fabric materials – fiber, felt and cloth – obtained from different precursor materials and prepared at various process conditions (oxidized, partially carbonized, carbonized, graphitized), were exposed to pulses of various lasers (Nd3+: YAG, alexandrite, ruby).

Depending on the laser power, plasma and destructive phenomena occurred. In the case of an interaction between a Nd3+: YAG laser beam and specimens of thickness in millimeter range, the authors have estimated the threshold of the energy density for drilling and discussed the possible models of the interaction.

The results have implications in the estimations of quality as well as in the improvement of material processing, giving some new light to the changes of mechanical and optical constants of the material, as well as to the changes of carbon groups of the material, which would be useful for different types of modeling. Future research will be in the interaction of laser beams with various textile materials, where the investigation would cover the microstructure changes and the implications on cloth cutting and welding, concerning the damages as well as relief structures, specially renew for fs laser regimes.

The area of laser applications in the textile industry is supported by scientific and applicative exploration. However, fewer results are concerned with deep introspection into the microstructure of the damages considering the laser interaction with carbon fiber and other carbon-based textiles.

Behind every successful technology is a great body of scientific knowledge. The paint industry managed to get along pretty well from the time of the Egyptians until World War I, a span of approximately 5,000 years, without much scientific insight. Indeed, the empirical approach to paint formulation could hardly be criticised. When one visits museums of Egyptology today, one sees coatings formulated three to five thousand years ago which are bright coloured and which still have good adhesion and film integrity. But coating mummy cases in a very dry climate is considerably less demanding than coating missiles which find themselves in a hostile environment. Although paint for mummy cases, houses, and barns and even the first assembly‐line‐produced automobiles could be made without much scientific understanding, it is fair to say that coatings for the exacting demands of modern technology could never have evolved without an understanding of the scientific principles on which the modern coatings industry is based. The scientific basis for the modern coatings industry is found in an understanding of polymer chemistry, an understanding of the chemistry of solvents, a knowledge of the chemistry of pigments, and a large body of physical chemistry relating to solubility, rheology, adhesion, cohesion, and many other important phenomena.

Recently, the requirement of the printed wiring boards (PWBs) of environmental harmony type has risen rapidly. We have developed the core technologies of halogen‐free. They consist of resin system technology and high filler content technology. The point of the resin technology is the development of a new resin system (RO resin) which takes nitrogen into the molecule frame in a large quantity. The point of the high filler content technology is the development of a new filler interphase control system (FICS) which enables the high dispersion of fillers. A variety of halogen‐free substrates which can be applied to the diversified needs have been developed by combining these technologies. They are MCL‐RO‐67G, thin laminate for the multi‐layer PWBs, MCF‐4000G, build‐up material for high density interconnect (HDI) , and MCL‐E‐679F(G), high Tg laminate for the advanced plastic IC packages (PKGs) and PWBs. These materials have excellent heat‐resistance, and are suitable for lead‐free solder as well. The robustness towards temperature, humidity and frequency of those materials is better than that of current materials. The synthetic board design of the environmental harmony type is facilitated by combined use of these materials. We are also developing several multi‐layer and build‐up materials, HDI for high frequency, high speed and high reliability application to meet the requirement of PWBs and advanced PKGs for the near future.

Sizing functions are crucial inputs for unstructured mesh generation since they determine the element distributions of resulting meshes to a large extent. Meanwhile, automating the procedure of creating a sizing function is a prerequisite to set up a fully automatic mesh generation pipeline. In this paper, an automatic algorithm is proposed to create a high-quality sizing function for an unstructured surface and volume mesh generation by using a triangular mesh as the background mesh.

A practically efficient and effective solution is developed by using local operators carefully to re-mesh the tessellation of the input Computer Aided Design (CAD) models. A nonlinear programming (NLP) problem has been formulated to limit the gradient of the sizing function, while in this study, the object function of this NLP is replaced by an analytical equation that predicts the number of elements. For the query of the sizing value, an improved algorithm is developed by using the axis-aligned bounding box (AABB) tree structure.

The local operations of re-meshing could effectively and efficiently resolve the banding issue caused by using the default tessellation of the model to define a sizing function. Experiments show that the solution of the revised NLP, in most cases, could provide a better solution at the lower cost of computational time. With the help of the AABB tree, the sizing function defined at a surface background mesh can be also used as the input of volume mesh generation.

Theoretical analysis reveals that the construction of the initial sizing function could be reduced to the solution of an optimization problem. The definitions of the banding elements and surface proximity are also given. Under the guidance of this theoretical analysis, re-meshing and ray-casting technologies are well-designed to initial the sizing function. Smoothing with the revised NLP and querying by the AABB tree, the paper provides an automatic method to get a high-quality sizing function for both surface and volume mesh generation.

This study aims to provide control of liquids, especially against water-based ink on the paper and paperboard surface with natural substances, in also practical and greenway.

The paper surface was treated with natural rosin and its derivatives to obtain a hydrophobic effect and to improve printing properties. The oleoresin samples collected from Pinus nigra Arnold and Pinus pinaster Aiton trees in the controlled area and turpentine content removed was by hydrodistillation. The gum rosin (GR), fortified 10% with maleic anhydride (MGR) and esterified with 10% pentaerythritol (PMGR) samples solved in a simply alcohol and sprayed the base paper surface directly with a spray gun. Base paper samples were paperboard, bleached paper and test liner paper. Then, flexo printing was applied and printability properties were measured.

The treatment weights of these paper samples were 1.8 ± 0.5, 1.3 ± 0.5 and 0.7 ± 0.2 g/m², respectively, compared to the base paper. Greater Cobb60 results were obtained from modified rosin samples than unmodified gum rosin-sized paperboards and the PMGR surface treatment reduces Cobb60 values by 20% and MGR treatment reduces 15% comparing to the base sheet. Then, the printing procedure was applied to the surface of the treated materials using a flexo printing system. As a result of the treatment better print density, chroma and print lightness value consumed a less hydrophobic agent and controlling water-based flexo ink on the base paper surface.

The unique aspect of this work was improving the hydrophobicity of the paper surfaces was achieved by spraying with natural rosin and derivatives.

Examines the fourteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.

Examines the fifthteenth published year of the ITCRR. Runs the whole gamut of textile innovation, research and testing, some of which investigates hitherto untouched aspects. Subjects discussed include cotton fabric processing, asbestos substitutes, textile adjuncts to cardiovascular surgery, wet textile processes, hand evaluation, nanotechnology, thermoplastic composites, robotic ironing, protective clothing (agricultural and industrial), ecological aspects of fibre properties – to name but a few! There would appear to be no limit to the future potential for textile applications.