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Machine may bo defined as a machine tool which removes metal by causing the work, securely held in a vice or fixture, to be fed against a revolving cutting tool, called the milling cutter, having one or more cutting edges—usually several.

This paper presents an offset‐based tool path generation method for STL format three‐dimensional (3D) models. The created tool‐paths can be effectively used to near‐net‐shaped parts, in particular those created using rapid prototyping.

The STL model is first offset by the distance of the selected cutter radius using a unique 3D offset method. The intersections between the top facing triangles of the offset model and tool‐path drive planes are calculated. The intersection line segments are sorted, trimmed and linked to generate continuous top envelope curves, which represent interference‐free tool paths.

The developed offset‐based algorithm can rapidly and successfully generate interference‐free tool paths as continuous lines, instead of a collection of discrete tool location points. The strategy of using adaptive step‐over distances based on local geometrical information can significantly increase machining efficiency.

The current tool path generation method only works for ball‐end mills. The entire surface of the STL model is treated as a single composite surface to be machined using raster milling. To improve machining efficiency, an automatic surface splitting algorithm could be developed to divide the model into several regions based on the characteristics of a group of triangular facets, and then machine these identified regions using different strategies and cutters.

The offset‐based tool‐path generation algorithm from STL models is a unique and novel development, which is useful in the rapid prototyping and computer‐aided machining areas.

The objective of CNC machining is to produce mechanical parts with designed quality most efficiently. To generate CNC tool paths for machining a sculptured part using a three‐axis CNC machine, surface geometry, cutter shape and size, as well as tool path interval and direction need to be considered. In this work, the relation between the direction of a tool motion and cutting efficiency is studied. A new measure of cutting efficiency in three‐axis CNC milling – the length of effective cutting edge (ECE) is introduced. The ECE length is mathematically proven to reach its maximum when the tool cuts a sculptured surface along its steepest tangent direction at the cutter contact point. The steepest tangent direction is thus proven to be the most efficient tool feed direction in three‐axis sculptured part machining. The study identifies tool feed direction as a new control parameter in CNC tool path planning, and forms the foundation for further research on three‐axis tool path generation of sculptured parts.

The purpose of this paper is to originate a statistical model for delamination factor, surface roughness, machining force and also to determine and compare the effects of machining parameters (spindle speed, fiber orientation angle, helix angle and feed rate) on the output responses during end-milling of glass fiber reinforced polymers (GFRP) by using desirability functional analysis (DFA) and grey relational analysis (GRA).

Based on Taguchi’s L27 orthogonal array, milling experiments were carried on GFRP composite plates employing solid carbide end mills with different helix angles. The machining parameters were optimized by an approach based on DFA and GRA, which were useful tools for optimizing multi-response considerations, namely, machining force, surface roughness and delamination factor. A composite desirability index was obtained for multi-responses using individual desirability values from DFA. Based on this index and grey relational grade the optimum levels of parameters were identified and significant contribution of parameters was ascertained by analysis of variance.

Fiber orientation angle (66.75 percent) was the significant parameter preceded by feed rate (15.05 percent), helix angle (7.76 percent) and spindle speed (0.30 percent) for GFRP composite plates.

Multi-objective optimization in end-milling of GFRP composites using DFA and GRA has not been performed yet.

Compared with the high stiffness of traditional CNC machine tools, the structural stiffness of industrial robots is usually less than 1 N/µm. Chatter not only affects the quality of robotic milling but also reduces the accuracy of the milling process. The purpose of this paper is to reduce chatter in the robotic machining process.

First, the mode coupling chatter mechanism is analyzed. Then the milling force model and the principal stiffness model are established. Finally, the robot milling stability optimization method is proposed. The method considered functional redundancies, and a new robot milling stability index is proposed to improve the quality of milling operations.

The experimental results prove a significant reduction in force fluctuations and surface roughness after using the proposed robotic milling stability optimization method.

In this paper, a new robot milling stability index and a new robot milling stability optimization method are proposed. This method can significantly increase the milling stability and improve the milling quality, which can be widely used in the industry.

The purpose of this paper is to analyze the literature that is currently available and take a glance at minimum quantity lubrication (MQL) with nanofluids (NFs) as viable candidates to improve the efficiency of various milling operations on challenging materials.

The extensive literature review is carried through the existing literature, which shows the effect of various process parameters in the milling operation of challenging materials under NF-MQL conditions. The manuscript also deals with identifying the inferences and research gaps from the literature review. The role and potential of NF-MQL in milling challenging materials are identified in this work.

The conclusion has also derived some recommendations for future study from the prior research, which will be helpful for any further research in this area.

This research work is limited to milling operations in challenging materials.

NF-MQL applications in milling operations are comparatively underexplored and merit considerable research. The amount of effort industry practitioners put into sustainable manufacturing will surely be greatly reduced by thorough research on the milling of challenging materials under NF-MQL settings.

MQL system has a great potential to perform well in the experimental endeavor. Despite that fact, majority of the small and medium scale manufacturing industries are still using the conventional flood system for the machining of the workpieces because of the unaffordable initial cost and requirement of expertise involved as compared to the flooded lubrication. This issue might be solved when more works will be accomplished in industries for small as well as medium scale production.

These are novel study approaches because there are so many variables that affect cutting efficiency; therefore, more research is required to assess and provide direction for the advancement of hard milling technology.

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2023-0010/

Accurate 3D experimental particle trajectory data, acquired from a laboratory tumbling mill using bi‐planar X‐ray filming, are used to validate the discrete element method (DEM). Novel numerical characterisation techniques are presented that provide a basis for comparing the experimental and simulated charge behaviour. These techniques are based on fundamental conservation principles, and provide robust, new interpretations of charge behaviour that are free of operator bias. Two‐ and three‐dimensional DEM simulations of the experimental tumbling mill are performed, and the relative merits of each discussed. The results indicate that in its current form DEM can simulate some of the salient features of the tumbling mill charge, however, comparison with the experiment indicate that the technique requires refinement to adequately simulate all aspects of the system.

This papers aims to provide a fixed cutter axis control (F-CAC) industrial robot (IR) milling for NURBS surfaces with large fluctuation, which can avoid over-cut and interference during IR milling in contrast to variable cutter axis control (V-CAC) IR milling.

After the design of a target surface, the IR reciprocating milling trajectory can be obtained using NURBS mapping projection method. A set of interpolation points of the reciprocating trajectory can be calculated using the equi-chord interpolation method. Combining with F-CAC method and curvature estimation, the IR reciprocating trajectory of the tool center point (TCP) without over-cut can be obtained. The programs corresponding to posture control using F-CAC can be generated by IR kinematics.

In contrast to the V-CAC milling method, the F-CAC method can machine successfully the NURBS surfaces with large fluctuation. The simulation and machining proves that F-CAC is feasible and effective to machine NURBS surface with large fluctuation without over-cut phenomenon. The F-CAC has wide application in carving and woodworking industry at present.

The F-CAC method is very practical and effective for IR milling of complex NURBS surfaces with large fluctuation without over-cut and interference phenomenon.

The objective of this paper is to develop geometric algorithms and planning strategies to enable the development of a novel hybrid manufacturing process, which combines rapidly re‐configurable mold tooling and multi‐axis machining.

The presented hybrid process combines advantages of both reconfigurable molding and machining processes. The mold's re‐configurability is based on the concept of using an array of discrete pins. By positioning the pins, the reconfigurable molding process allows forming the mold cavity directly from the object's 3D design model, without any human intervention. After a segment of the part is molded using the reconfigurable molding process, a multi‐axis machining operation is used to create accurate parts with better surface finish. Geometric algorithms are developed to decompose the design model into segments based on the part's moldability and machinability. The decomposed features are used for planning the reconfigurable molding and the multi‐axis machining operations.

Computer implementation and illustrative examples are also presented in this paper. The results showed that the developed algorithms enable the proposed hybrid re‐configurable molding and multi‐axis machining process. The developed decomposition and planning algorithms are used for planning the reconfigurable molding and the multi‐axis machining operations. Owing to the decomposition strategy, more geometrically complex parts can be fabricated using the developed hybrid process.

This paper presents geometric analysis and planning to enable the development of a novel hybrid manufacturing process, which combines rapidly re‐configurable mold tooling and multi‐axis machining. It is expected that the proposed hybrid manufacturing process can produce highly customized parts with better surface finish, and part accuracy, with shorter build times, and reduced setup and tooling costs.

Owing to the consolidation and globalization of the paper industry, manufacturing units have keen interest to focus on particular product groups. While this specialization will create opportunities for scale economics in production, management of supply chains becomes increasingly challenging, as one particular manufacturing unit serves a number of different sales locations. The aim of this paper is to identify improvement areas in the new supply chain context of paper production, and possibly give further support for the general discipline development.

Research work is based on two different case studies completed for one major North‐European paper manufacturer, which is mostly serving its customers in Europe and the USA. The first case study (a preliminary one) started when supply chain challenges were recognized at the end of the 1990s, and a manufacturing unit was seeking managerial remedies – this investigation only concerned one manufacturing unit, while not singling cut any particular supply chain in the analysis. During the most recent years a more detailed case‐study was conducted with this paper manufacturer, which concerned lead time performance of four different strategically important supply chains. These supply chains were championed by two different large manufacturing units (the preliminary analysis concerned one of these two paper mills). The objective of this research work is to identify whether general lead time and response studies, mostly completed in the automotive industry, are applicable to paper production.

According to the analysis North‐European paper manufacturers hold approximately 45 days of distribution inventory. Interestingly, in the case study it was found that in distribution this does not result in high efficiency–on the contrary different parties involved (railway, port operations and vessels) need to have a considerable amount of free and unused capacity in their operations to ensure the smooth flow of materials.

The case studies were conducted in the factories of one large North‐European multinational. Therefore, the observations are limited to this company. However, in order to generalize the results further, the authors have analysed North‐European paper producers through macro data and financial reports in any research environment. To cover a mismatch between company level quantitative analysis and macro data, the authors consulted several key persons in the case company concerning the research results. Therefore, triangulation in the empirical data was achieved.

It is argued that four reasons, namely: scale emphasis in production, IT systems to support supply chains, sea shipment, and outsourced distribution, play a vital role in the forthcoming performance improvement initiatives. At the moment this results in long supply chain lead times, whatever the distance to the actual market. Decision makers in practice need to find solutions for these in order to improve performance further.

Supply chains are rarely analyzed in research works through more than one supply chain – here analysis of four different supply chains concerning lead time is provided. The analysis is based on the enterprise resource‐planning database, and findings are verified with interviews with the managers and directors of the case company.