Jeffrey R. Alcock

A review of micro-powder injection moulding as a microfabrication technique

Micro-powder injection moulding (µPIM) is a fast-developing micro-manufacturing technique for the production of metal and ceramic components. Shape complexity, dimensional accuracy, replication fidelity, material variety combined with high-volume capabilities are some of the key advantages of the technology. This review assesses the capabilities and limitations of µPIM as a micro-manufacturing technique by reviewing the latest developments in the area and by considering potential improvements. The basic elements of the process chain, variant processes and simulation attempts are discussed and evaluated. Challenges and research gaps are highlighted, and potential areas for improvement are presented.

Aqueous colloidal processing and green sheet properties of lead zirconate titanate (PZT) ceramics made by tape casting

An aqueous system for tape casting PZT ceramics was developed using poly (vinyl alcohol) binder, poly (propylene glycol) plasticizer, D3021 dispersant and Surfynol SE-F wetting agent. Screening experiments were performed to assess the stability of the suspension in the presence of the dispersant by performing pH, conductivity and Zeta potential measurements. Viscosity measurements were used to find the optimum level of dispersant needed to produce a stable slip at pH 10.2. Subsequently, the rheological and mechanical characteristics were also investigated.

Modelling collaboration using complex networks

Collaboration means working together to achieve a common goal or to solve a problem, and in modern businesses, it is an important factor for information sharing and quality. This is due to the ability of collaborations to shape the structure and behaviour of organisations through the pooling of expertise and standardising of work patterns. Grounded on complex network theory and collaborative design research, a mathematical model of information flow for analysing collaboration in organisations is proposed in this article. The model defines concepts for characterising organisational structures for collaboration and proposes indicators for assessing organisational behaviour in terms of collaboration within organisations. The article concludes by discussing the applications and limitations of the proposed model.

Modelling information flow for organisations: A review of approaches and future challenges

Abstract Modelling is a classic approach to understanding complex problems that can be achieved diagrammatically to visualise concepts, and mathematically to analyse attributes of concepts. An organisation as a communicating entity is a made up of constructs in which people can have access to information and speak to each other. Modelling information flow for organisations is a challenging task that enables analysts and managers to better understand how to: organise and coordinate processes, eliminate redundant information flows and processes, minimise the duplication of information and manage the sharing of intra- and inter-organisational information. The purpose of this article is to review literature for diagrammatically and mathematically modelling information flow for organisations and to identify problems facing information flow modelling research. The article will focus on research articles to identify: (1) approaches for diagrammatically modelling information flow, (2) approaches for mathematically modelling information flow, and (3) the current state of information flow modelling research. The article concludes by identifying and discussing possible future challenges for information flow modelling research.

Review of Factors that Affect Shrinkage of Molded Part in Injection Molding

Purpose: This paper reviews the factors affecting shrinkage of molded parts in injection molding. Methods: A selective screening of the papers published in the last 10 years was adopted. The review was organized according to molding scale (macro or micro) and by considering four branches of influence: material behaviors, processing parameters, mold, and specimen design. Results: Within the interval of confidence, at the macroscale, critical processing parameters were the temperatures, the packing parameters, cooling time, and injection speed; temperatures and packing parameters resulted critical factors at the microscale as well. Concerning the design aspects, the runner size and the ribs affect shrinkage at the macro and microscale, respectively. The analysis of the literature review has shown an absence of statistical approach for determining the material influences, a lack of information on shrinkage occur in powder-molded parts and the absence of data in specimen with dimensions below 10 µ. Conclusions: The review collected the factors that affect shrinkage in injection molding, and identified three possible areas for further works.

Data uncertainty assessment and information flow analysis for product-service systems in a library case study

The provision of service is increasingly becoming a key driver for delivering customer value. This emphasis on service provision is promoted by approaches such as Product-Service Systems (PSSs) that deliver value in use based on integrated products and services. However, to achieve effective delivery of services, it is important to manage information flow and data uncertainty associated with information requirement. The paper proposes a methodology that consists of: (a) the assessment of data uncertainty through the numeral, unit, spread, assessment and pedigree approach and a pedigree matrix consisting of data uncertainties to be scored based on their influence on the system; and (b) the analysis of information flow by means of data flow diagrams that depict information exchanges and an info-dynamic engine that measures the efficiency and recommends improvements for information flows in PSSs. A library case study was undertaken to show how such a methodology can be applied.

Co-injection promises further growth for MIM

Abstract The Cranfield team has shown that PCM is a viable process for the manufacture of surface-engineered components, and that PCM can lead to cost savings over the standard MIM process. By ensuring optimized mould filling conditions and compatible sintering characteristics between skin and core materials, high quality components of complex geometry can be produced. The team believes that the ability to surface engineer as part of the MIM cycle provides a further incentive for the additional exploitation of this gast growing technology.

Flatness optimization of micro-injection moulded parts: the case of a PMMA microfluidic component

Micro-injection moulding (µ-IM) has attracted a lot of interest because of its potential for the production of low-cost, miniaturized parts in high-volume. Applications of this technology are, amongst others, microfluidic components for lab-on-a-chip devices and micro-optical components. In both cases, the control of the part flatness is a key aspect to maintaining the components functionality. The objective of this work is to determine the factors affecting the flatness of a polymer part manufactured by µ-IM and to control the manufacturing process with the aim of minimizing the in-process part deformation. As a case study, a PMMA microfluidic substrate with overall dimensions of 10 mm diameter and 1 mm thickness was investigated by designing a µ-IM experiment having flatness as the experimental response. The part flatness was measured using a micro-coordinate measuring machine. Finite elements analysis was also carried out to study the optimal ejection pin configuration. The results of this work show that the control of the µ-IM process conditions can improve the flatness of the polymer part up to about 15 µm. Part flatness as low as 4 µm can be achieved by modifying the design of the ejection system according to suggested guidelines.

Information channel diagrams: an approach for modelling information flows

In this article, the ‘information channel diagram’ (ICD) approach is introduced as a diagrammatical tool for modelling information flow during the delivery phase of organisations in which goods are deployed or delivered to customers. An initial review and evaluation of current tools for modelling information flow will be conducted based on the characteristics of information flow during the delivery phases in organisations. Diagrammatic primitives and a prescribed modelling methodology for developing an ICD will be presented, and a case scenario of the delivery phase of an organisation within the health care sector will be applied to demonstrate the use of the ICD. The article concludes by discussing some applications, generalisation potential and limitations of the ICD approach.

Managing integrated information flow for delivery reliability

Purpose – The purpose of this paper is to explore the management of information flow for delivery reliability. It analyses how the integration strategies of traceability, transaction costs and vertical integration that shape integrated information flow are managed during delivery processes of firms. While delivery reliability contributes to firm competitiveness, information flow is central to firms interaction internally and externally to facilitate delivery. Design/methodology/approach – The paper applies an exploratory multiple-case study involving 21 delivery team members in three industrial technology-based firms. Informed by a multidisciplinary framework from literature, the study captures “what” and “how” existing firms manage information flow during delivery. Individual cases from the company were compared analysed to determine themes that drive delivery-related integrated information flow management. Findings – The paper finds that case firms prioritised understanding interaction logics, maintaini...