CTW

In many industrial applications, a modification of the surface geometry can enhance the tribological behavior of contacts to a favorable condition. In this paper, the effect of surface texturing on the film thickness in parallel sliding surfaces is investigated. It is shown that surface texturing can improve film formation and as a result the load carrying capacity. With the numerical model developed and by considering cavitation, the effect of shape, depth, size and textured area fraction on the film thickness is studied. Further, the optimum size for the most beneficial texturing pattern with respect to film thickness is discussed.

In many industrial applications, a modification of the surface geometry can enhance the tribological behaviour of lubricated sliding contacts. In this paper, the effect of surface texturing on the coefficient of friction in parallel sliding lubricated surfaces is investigated. It is shown that surface texturing can improve film formation and, as a result, the load-carrying capacity as well as a reduction in the coefficient of friction. With the numerical model developed, and by considering cavitation, the effects of shape, depth, size, and the textured area fraction on the frictional behaviour of parallel sliding lubricated contacts under conditions of mixed lubrication is studied. In this article it is shown that the surface texturing can have a beneficial effect, in order to decrease friction.

Considering the influence of wall slip on fluid flow is important for many engineering topics involving liquid-solid interfacial phenomena, such as flow through porous media, liquid coatings and lubrication. Boundary slip can act as a method to reduce friction in lubricated contacts. Furthermore, surface texturing can also play a positive role to enhance the film thickness. Therefore, combination of these two methods can be beneficial in order to improve the tribological performance of lubricated contacts. Although, in recent years the study of frictional behaviour of surface with boundary slip is getting more attention, the combination of these two methods of surfaces properties modification is interesting to investigate. For the no-slip boundary condition, the first layer of fluid molecules has the same velocity as the contacting solid surface and this condition has been widely applied in the field of fluid mechanics. In lubricated contacts with boundary slip, the first layer of the lubricant molecules move with a different velocity from that of the solid surface. In this article, the frictional behaviour of boundary slip in parallel sliding lubricated contacts for textured surfaces is investigated. This study shows that boundary slip has a significant influence on the film thickness in case of textured surfaces. Furthermore, it is possible to increase the film thickness, and enhance the frictional behaviour by modifying the boundary slip parameters.

In industrial applications, a starved lubrication condition may occur, leading to a reduction in film thickness; by modifying the surface geometry, the tribological performance of the contact is enhanced. In this paper, the influence of surface texturing as a method for reducing the friction on the film thickness in parallel sliding surfaces for starved lubricated contacts is investigated. The results in this study have shown that surface texturing can improve film formation for starved lubricated contacts and, respectively, the load carrying capacity. The effect of starvation on several texturing patterns with several texturing properties was investigated and the film thickness for these conditions was studied. With the numerical algorithm developed and taking cavitation into consideration, the effect of shape, depth, size, and texture pitch on the film thickness was studied.

Starvation occurs when the lubricated contact uses up the lubricant supply, and there is not enough lubricant in the contact to support the separation between solid surfaces. On the other hand, the use of textures on surfaces in lubricated contacts can result in a higher film thickness. In addition, a modification of the surface's geometrical parameters can benefit the tribological behaviour of the contacts. In this article, for parallel sliding surfaces in starved lubricated conditions, the effect of surface texturing upon the coefficient of friction is investigated. It is shown that surface texturing may improve film formation under the conditions of starvation, and as a result, the frictional behaviour of the parallel sliding contact. Furthermore, the effect of starved lubrication on textured surfaces with different patterns in the presence of a cavitation effect, and its influence on frictional behaviour, is investigated. It is shown that surface texturing can reduce the coefficient of friction, and that under certain conditions, the texturing parameter could have an influence on the frictional behaviour of parallel sliding contacts in the starved lubrication regime.

of contacts to a favourable condition. In this paper, the effect of surface texturing on the film thickness in parallel sliding surfaces is investigated. It is shown that surface texturing can improve film formation and, as a result, the load-carrying capacity. With the numerical model developed and by taking cavitation into account, the effect of shape, depth, size and textured area fraction on the film thickness is studied. Further, the optimum size for the most beneficial texturing pattern with respect to film thickness is discussed.

As an implicit subset of industrial design engineering, packaging development and management thereof has long been a changeling, because product and packaging development are usually regarded in a similar manner. At the same time, there is a clear difference between packaging design and product design. The packaging explicitly serves the content and, therefore, in most cases, packaging is of low economic value. For this reason, new packaging design is all too often subject to standard or existing packaging solutions. Besides this, packaging development has specific requirements, because it has to preserve and protect its content, which gives many technical requirements. Other important requirements are based on legislation, market acceptance, the environmental impact and usability. This implies that education in packaging development cannot be a carbon copy of the education in product development. Often, even more fields of expertise are involved, while having to meet all restrictions related to developing feasible and realistic packages in a shorter time-frame. This publication describes how project-led education is employed in an educational approach that allows students to adequately address the development of content-packaging combinations in a structured, effective and efficient manner. With this, the development efforts spent on product and packaging can become more in balance, not only doing justice to the separate life cycles of the two, but especially to the benefit of the combined life cycle of the content-packaging combination.

In order to integrate sustainability in the development of content-packaging combinations, the consequences of decisions for the entire life cycle need to be analyzed in early stages of the development process. To adequately underpin these decisions, several aspects, for example the economic and the environmental impact, need to be assessed. A so-called actor network is developed to support designers in decision making. This publication examines practical use situations of this actor network tool based on information from research partners. Scenarios are written in order to depict requirements for the actor network tool, considering different users and functionalities.

An auspicious approach to increase sustainability of a product/packaging cycle is to investigate the dependencies between the different life cycle phases and corresponding actors. For any actor, the perspective on the global cycle initiates from his own position; therefore, it is required to make the entire life cycle more transparent by showing and interpreting the dependencies as well as the correlations and sensitivities of the different phases in the life cycle. The emerging actor network can serve as a fundament for an approach that allows for the meaningful comparison of various aspects of sustainability during the development life cycles of product/packaging combinations.

Packaging designers often come up with splendid design proposals, without being aware of technical, marketing or economical restrictions. This leads to infeasible proposals, so many packaging design projects fail. To bridge the gap between design and marketing, a tool has been developed that shows several designs to an extensive community. Designers now have the possibility to get feedback of the target market on the design proposals. In a case study (redesigning a packaging), the tool clearly showed its advantage. This paper discusses the tool, its usage and its contribution to a more effective and efficient development cycle in packaging development. 1 INTRODUCTION A strong characterization of packaging design is the amount of aspects that have to be taken into concern during the design process [1]. This asks for adequate management of the development cycle, and especially of the design and engineering decisions taken. To depict the decision process, a decision model can be used. ...

A life cycle assessment (LCA) is a tool for determining impacts on the environment. LCA's cover the entire life cycle of an artefact, from raw materials to recycling or disposal. For assessments of packaging, the life cycles of both the packaging and the packaged content need to be taken into account, because these life cycles are strongly interrelated. A case study demonstrates these interrelations and their consequences. It also shows the ambiguity and non-decisiveness due to the subjectivity in the selection of data sources, impact assessment methods, system boundaries and software tools. To attain purposeful LCA's, the assessments must adhere to the expertise related to product/packaging combinations. This publication addresses the data sources, impact assessment methods, system boundaries and tools involved in LCA's for product/packaging combinations; it elaborates on how the outcomes of assessments vary with these aspects. The case study is used to illustrate the results.

The current Dutch recycling value chain for plastic packaging waste (PPW) has not reached its full circularity potential, as is apparent from two Circular Performance Indicators (CPIs): net packaging recycling rate and average polymer purity of the recycled plastics. The performance of the recycling value chain can be optimised at four stages: packaging design, collection, sorting, and recycling. This study explores the maximally achievable performance of a circular PPW recycling value chain, in case all stakeholders would implement the required radical improvement measures in a concerted action. The effects of the measures were modelled with material flow analysis. For such a utopic scenario, a net plastic packaging recycling rate of 72% can be attained and the produced recycled plastics will have an average polymeric purity of 97%. This is substantially more than the net packaging recycling rate of 37% for 2017 and will exceed the EU target of 50% for 2025. In such an ideal circul...

The response surface method (RMS) was used to optimize the color strength (K/S) of the wool fibers dyed with Isatis tinctoria. The eight independent variable terms, in which two of them are categorical and the other six numerical, were selected at two levels (low and high). The ANOVA test results of the linear model showed that the model terms, including reducing agent amount, dyeing temperature, dyeing time, and dyestuff percentage, have a significant effect on K/S. The actual values agreed with the predicted values and the suggested equation model was satisfactory and accurate.

Direct additive manufacturing (AM) of sensors has in recent years become possible, but still remains a largely unexplored area. This work proposes a novel resistive sensor design that utilizes the geometric freedom offered by AM, especially by material extrusion, to enable a customizable and amplified response to force and deformation. This is achieved by using a multi-material design made of an elastomer and an electrically conductive polymer that enables a physical shortening of the conductive path under compressive load through a specific definition of shape. A number of different variants of this novel sensor design are tested, measuring their mechanical and electrical behavior under compression. The results of these tests confirm a strong resistive response to mechanical loading. Furthermore, the results provide insight into the influencing factors of the design, i.e., the gap size between the conductive pathing and the stiffness of the sense element support structure are found...