Search results

For additive manufacturing (AM) through laser-based powder bed fusion of polymers (PBF-LB/P), accurate characterization of powder flowability is vital for achieving high-quality parts. However, accurately characterizing feedstock flowability presents challenges because of a lack of consensus on which tests to perform and the diverse forces and mechanisms involved. This study aims to undertake a thorough investigation into the flowability of eight feedstock materials for PBF-LB/P at different temperatures using various techniques.

For ambient temperature assessments, established metrics such as avalanche angle and Hausner ratio, along with the approximated flow function coefficient (FFC_app), are used. The study then focuses on the influence of elevated temperatures representative of in-process conditions. FFC_app and differential scanning calorimetry (DSC) are performed and analyzed, followed by a correlation analysis as a holistic approach to identify key aspects for flowability. Furthermore, two feedstock materials are compared with a previous study to connect the present findings to PBF-LB/P processing.

The study revealed intrinsic material properties such as mechanical softening near the melting point to become significant. This partially explains why certain powders with poor ambient temperature flowability are consistently demonstrated to produce high-quality parts. FFC_app and thermal characterization through DSC are identified as critical metrics for optimizing feedstock material characteristics across temperature ranges.

Previous studies emphasized specific characterizations of feedstock material at ambient temperature, presented a limited materials selection or focused on metrics such as shape factors. In contrast, this study addresses a partially understood aspect by examining the critical role of temperature in governing feedstock material flowability. It advocates for the inclusion of temperature variables in flowability analyses to closely resemble the PBF-LB/P process, which can be applied to material design, selection and process optimization.

Powder bed-based additive manufacturing (AM) is a promising family of technologies for industrial applications. The purpose of this study is to provide a new metrics based on the analysis of the compaction behavior for the evaluation of flowability of AM powders.

In this work, a novel qualification methodology based on a camera mounted onto a commercially available tap density meter allowed to assess the compaction behavior of a selection of AM materials, both polymers and metals. This methodology automatizes the reading of the powder height and obtains more information compared to ASTM B527. A novel property is introduced, the “tapping modulus,” which describes the packing speed of a powdered material and is related to a compression/vibration powder flow.

The compaction behavior was successfully correlated with the dynamic angle of repose for polymers, but interestingly not for metals, shedding more light to the different flow behavior of these materials.

Because of the chosen materials, the results may lack generalizability. For example, the application of this methodology outside of AM would be interesting.

This paper suggests a new methodology for assessing the flowing behavior of AM materials when subjected to compression. The device is inexpensive and easy to implement in a quality assurance environment, being thus interesting for industrial applications.

Consumers seem to be increasingly concerned about the environmental and social consequences of their purchases. For this reason, companies are involved in corporate social responsibility (CSR) strategies for their supply chain to responsibly manage the consumption of the environmental resources and to support sustainability. The purpose of this paper is to contribute to a better understanding of the Italian organic apparel consumer by investigating the importance of consumers’ attitudes towards CSR in agricultural products processing industries and their willingness to pay (WTP) for organic cotton clothing.

Questionnaire data were gathered in Italy on a Likert scale. Questions focussed on WTP for organic cotton, with the aim to test consumer responsiveness to a CSR initiative in Italy. A structural equation model is proposed to shed some light into this relatively unexplored area.

One of the direct implications of the authors’ study is that companies in apparel industry should try to improve their social and environmental performance to elicit the desired consumer responses.

This implies important managerial implications for new marketing strategies. If consumers’ perception of CSR practices drives their behavioural intention, firms will be motivated to be involved and to invest in socially responsible practices.

Alternative food networks (AFNs) have recently emerged in the food landscape as new ways of food production, distribution and consumption which are alternatives to the traditional food system. Drawing on the tragedy of the commons, this paper aims to test the role played by social capital and transparency in reducing customer's lethargy and thus enhancing AFN performance in terms of frequency and quantity of purchases made by customers.

An ordered probit model was used to analyse data from a strong database of 2,115 Italian AFN customers. Given the novelty of the topic, the quantitative survey was anticipated by a preliminary qualitative study based on in-depth interviews, focus groups and participant observation.

Customers play an active role in AFN communities, co-creating value together with the other actors of the network. The two independent variables tested in this model, social capital and transparency, positively and significantly affect customers' quantity and frequency of purchases within AFNs, reducing the occurrence of the tragedy of commons.

To the authors' knowledge, this study represents one of the first attempts to measure, through a quantitative method, the effect of performance drivers (i.e. social capital and transparency) on AFN performance. Theoretical, managerial and policy implications will be thoroughly presented and discussed along the paper.