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The purpose of this paper is to present the findings on jet array instabilities of molten caprolactam. Initial investigations showed that although a suitable range of parameters was found for stable jetting, there were cases where instabilities occurred due to external sources such as contamination.

The inkjet system consisted of a melt supply unit, filtration unit and printhead with pneumatic and thermal control. A start‐up strategy was developed to initiate the jetting trials. A digital microscope camera monitored the printhead nozzle plate to record the jet array stability within the recommended range of parameters from earlier research. The trials with jet instabilities were studied to analyse the instability behaviour.

It was found that instabilities occurred in three forms which were jet trajectory error, single jet failure and jet array failure. Occasionally, the jet with incorrect trajectory remained stable. When a jet failed, bleeding of melt from the nozzle due to the actuations influenced the adjacent jets initiating an array of jets to fail similar to falling dominos.

The research concept is novel and investigating the jet array instability behaviours could give an understanding on jetting reliability issues.

This study aims to fabricate and study the effect of five cumulative graphite (G) and graphite nanoplatelets (GNP) filler loading composites by polymerising PA6 precursor; monomer epsilon caprolactam with the two carbons in situ while taking cognisance of the mixing effects (simultaneous stirring and sonication at varying amplitudes and duration). Different aspect ratios will be used to model the two streams of polymerisations.

High viscosity extrusion grade PA6 and synthetic G of less than 2 µm particle size were used as fillers. GNP and G are dried for 6 h in vacuum oven at 90°C. Prior to in situ polymerisation, probe sonication was applied to disperse fillers in molten ɛ-caprolactam, the PA6 monomer. Five carbon loadings were made, that is 5–25 Wt.% for G and 0.5–2.5 Wt.% for GNP composites. Two different sonification regimes were applied 20% sonication amplitude for 20 min (20/20) and 40% sonication amplitude for 10 min (40/10).

Better tensile properties were achieved using the 20/20 processing streams for both G and GNP. The G- and the GNP-based composites systems of the 20/20 processing stream had tensile modulus and yield strength retained or improved above the unfilled PA6 value. The highest modulus obtained in the 20/20 streams are 1,878 and 1,201 MPa, respectively, for GNP and G at the highest loading levels, while the 40/10 processing streams had 963 and 1,247 MPa, respectively, for the GNP and G.

To the best of the authors’ knowledge, nobody has ever used sonification amplitude to compare mechanical properties.

In industry today the majority of managers appear to be aware of the importance of the purchasing function in manufacturing organisations and of the need to secure supplies of materials at the best available prices. What is not well recognised, however, especially by the senior non‐purchasing managers in the majority of manufacturing organisations, is the need to consider purchasing as a risk‐taking function and the need for supply management to be involved in strategic planning processes. Furthermore, there is a growing body of evidence to suggest an alarming ignorance of the need for senior executives in procurement operations to make strategic evaluations of their supply markets, to evaluate the risks involved in particular supply channels and to be able to relate these to their company's marketing objectives. The strategic planning requirements of purchasing are not well understood at a fundamental level and this may, in part, explain the view held widely in manufacturing organisations that purchasing is essentially an administrative function, concerned mainly with administrative procedures and tactical decisions, and need not be involved in the forward corporate strategy and planning processes of the organisation.

Jetting‐based additive manufacturing processes are gaining attention due to their high speed of operation, accuracy and resolution. Support material plays an important role in the additive manufacturing of parts by using processes that utilise jetting (inkjet) technology. This research aims to present novel support material compositions consisting of methylcellulose (MC) and propylene glycol or butylene glycol. These compositions form gels which are easy to remove and provide the advantage of reusability.

MC was mixed in propylene glycol or butylene glycol in different concentrations and examined for gel formation on heating and subsequent cooling. The viscosity and surface tension of these compositions were measured at temperatures suitable for jetting. Gel strength was characterised using texture analysis.

The viscosity and surface tension values at elevated temperatures (i.e. 800°C) show the suitability of these compositions for jetting‐based additive manufacturing processes. Due to their softness, these gels can be removed easily and their low melting points (i.e. near 500°C) allow their reusability as support materials.

This paper provides a novel approach of using polymer gels as support materials for additive manufacturing processes. These gels are easy to prepare and enhance the sustainability due to their reusability.

Although, MC in water have shown to form gels and these aqueous gels have been used in many applications such as medicine and food industries, the compositions presented in this paper are unique. Such combinations of MC and non‐aqueous solvents (i.e. propylene glycol and butylene glycol) have not been discussed before and provide an early step towards a new application area (i.e. additive manufacturing) for these gels.

As technology becomes more complex, the need for coatings of specialised functions continues to increase. The electronics industry, for example, makes demands on the coating industry for both conductive and insulation coatings. Highly temperature‐resistant coatings played a key role in the aerospace industry. Fire retardants contribute to consumer safety and coatings for plastics serve a number of protective and decorative functions.

In recent years aluminium has become a very widely used material in the construction industry. Light weight, good corrosion resistance and ease of fabrication lends itself to a whole variety of end uses. Although the tendency for aluminium to oxidise in the atmosphere is itself a form of chemical “protection”, improvements in weather and chemical resistance can be gained from the use of a variety of surface coatings. These coating technologies are typically of the following types: polyvinylidine difluoride, water‐borne electro‐paint, conventional solvent‐based paints, powder coatings and anodising. The two most popular technologies in use today are: TGIC (Triglycidyl isocyanurate)/polyester powder coatings and polyvinylidine difluoride (PVDF) solvent‐based coatings. Coated aluminium has the added competition in the window frame and door frame market from uPVC. Only coated aluminium will be discussed in this paper.

The Torpedo Marine Division of Berger Chemicals have appointed Mr George Topping as South East regional manager.

The purpose of this paper is to examine sustainability with an emphasis on China.

The paper examines previous research on sustainability and polymer chemistry to provide a better understanding of the importance of sustainability and technology in China.

There are many different perspectives when it comes to sustainability and that multiple stakeholders need to be considered when examining sustainability.

As the longest serving member of the American Chemical Society (ACS) accreditation committee and a Fellow of the ACS, the perspective on which this paper is based comes from over 1,000 publications and over 45 years of active research in the sciences and technology.

This paper aims to measure exposures to airborne contaminants during three-dimensional (3-D) printing and post-processing tasks in an industrial workplace.

Contaminant concentrations were assessed using real-time particle number (0.007 to 1 µm) and total volatile organic compound (TVOC) monitors and thermal desorption tubes during various tasks at a manufacturing facility using fused deposition modeling (FDM^TM) 3-D printers. Personal exposures were measured for two workers using nanoparticle respiratory deposition samplers for metals and passive badges for specific VOCs.

Opening industrial-scale FDM^TM 3-D printer doors after printing, removing desktop FDM^TM 3-D printer covers during printing, acetone vapor polishing (AVP) and chloroform vapor polishing (CVP) tasks all resulted in transient increases in levels of submicrometer-scale particles and/or organic vapors, a portion of which enter the workers’ breathing zone, resulting in exposure. Personal exposure to quantifiable levels of metals in particles <300 nm were 0.02 mg/m³ for aluminum, chromium, copper, iron and titanium during FDM^TM printing. Personal exposures were 0.38 to 6.47 mg/m³ for acetone during AVP and 0.18 mg/m³ for chloroform during CVP.

Characterization of tasks provided insights on factors that influenced contaminant levels, and in turn exposures to various particles, metals < 300 nm and organic vapors. These concentration and exposure factors data are useful for identifying tasks and work processes to consider for implementation of new or improved control technologies to mitigate exposures in manufacturing facilities using FDM^TM 3-D printers.

Over the last few years, the share of powder coatings used for the protection of aluminium extrusions and claddings for architectural uses in competition with conventional liquid paints and as an alternative to anodising has sharply increased. In 1987, about 47 million m2 or 135 thousand tons of aluminium used in outdoor architecture have been powder coated in France, Germany, Italy and United Kingdom. This paper gives a thorough description of the latest developments of the polyester powder coating systems used for aluminium extrusions and claddings in Europe, underlining the criteria of the choice of the weathering resistant powders, the importance of metal pretreatment and of the coating process itself as well as of the quality control in this industry. A comparison with competitive coating technologies is also given.