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The perforated paper honeycomb structure with double-hole in cell walls is one kind of innovative sandwich structure also to improve drying process of traditional honeycomb paperboard. Based on the analytical calculation, experiment inspection and finite element analysis, this paper is focus on the paper honeycomb core layer with double-hole in cell walls, and especially studies the bending and folding deformation and the compressive strength under out-of-plane quasi-static compression for different humidity. The structure first appears elastic buckling and folds near the circular holes in the cell wall, and goes on buckling, folding and crushing until to the densification with the continuously increase of compression set. Its quasi-static compressive stress and strain curve mainly shows four kinds of compression deformation processes, such as linear elastic stage, elastic yielding stage, plastic collapse stage, and densification stage. The critical stress and plateau stress of the structure slowly decrease with the increase of humidity and aperture, and the multiple linear regression analysis result illustrates that the relative humidity has much more influence on the critical stress and plateau stress. For different humidity and aperture, the analytical calculation result is close to the experiment result. However, the finite element simulation result greatly deviates from the above two results, especially for relative humidity 50% and 60% cases. [ABSTRACT FROM AUTHOR]

The pick up and place procedure is one of the essential tasks for handling and transporting the paper coils during diverse cycles of operation in paper industries. The metallic grippers are widely used in several industries for material handling and process automation. The aim of this research is to develop a new approach to handle the soft rolled coils without affecting the orientation of the material. Silicone grades 20, 40, 60 and 80 are selected and the blended polymers of silicone 20/80 and silicone 40/60 grades are synthesized through two roll millings followed by compression molding. The dumb bell samples are prepared as per ASTM D412 standard and uniaxial tensile testing is conducted in Inston machine. The strain-stress data at the strain rate of 250 mm/minute are recorded and the tensile strength of the blended polymers is measured. The results were reasonably good and suggested that the silicone soft gripper system with an acceptable accuracy can be recommended for handling paper coil without any deformations and unwanted marks during handling. [ABSTRACT FROM AUTHOR]

Cement stabilization is a widely applied technique in improving the workability and geotechnical properties of soft clay. This paper investigated the influence of cement stabilization on the soil–water characteristic curve (SWCC) and the deformation behavior of unsaturated cement–stabilized soft clay. The combined effect of cementation and partial saturation on the hydromechanical behavior of cement-stabilized soils was discussed. The SWCC of stabilized soil was measured in the full suction range under drying and wetting paths using the pressure plate method, the filter paper method, and the vapor equilibrium technique. The deformation behaviors of cement-stabilized soft soil were investigated by conducting suction-controlled oedometer tests. Furthermore, scanning electron microscope micrographs and mercury intrusion porosimetry tests were performed to investigate the effects of cement content on the evolution of soil pore structures. The test results showed that the water retention capacity of the stabilized soft clay increased with increasing cement content. The SWCC showed a significant hysteretic behavior in the boundary effect zone and transition zone, whereas the hysteretic effect was unapparent in the residual zone. The increased cement content had a more significant hysteretic effect on the SWCC. The deformation resistance capacity increased as the cement content and matric suction increased. However, the effect of matric suction on deformation resistance capacity decreased as the cement content increased. With the increase in cement content, the macropores were converted to small interaggregate pores, the pore spaces were distributed more uniformly, and the particle surface became rougher, resulting in higher water retention capacity and significant hysteresis of the SWCC. [ABSTRACT FROM AUTHOR]

The cost of specialized scientific equipment can be high and with limited funding resources, researchers and students are often unable to access or purchase the ideal equipment for their projects. In the fields of materials science and mechanical engineering, fundamental equipment such as tensile testing devices can cost tens to hundreds of thousands of dollars. While a research lab often has access to a large-scale testing machine suitable for conventional samples, loading devices for meso- and micro-scale samples for in-situ testing with the myriad of microscopy tools are often hard to source and cost prohibitive. Open-source software has allowed for great strides in the reduction of costs associated with software development and open-source hardware and additive manufacturing have the potential to similarly reduce the costs of scientific equipment and increase the accessibility of scientific research. To investigate the feasibility of open-source hardware, a micro-tensile tester was designed with a freely accessible computer-aided design package and manufactured with a desktop 3D-printer and off-the-shelf components. To our knowledge this is one of the first demonstrations of a tensile tester with additively manufactured components for scientific research. The capabilities of the tensile tester were demonstrated by investigating the mechanical properties of Graphene Oxide (GO) paper and thin films. A 3D printed tensile tester was successfully used in conjunction with an atomic force microscope to provide one of the first quantitative measurements of GO thin film buckling under compression. The tensile tester was also used in conjunction with an atomic force microscope to observe the change in surface topology of a GO paper in response to increasing tensile strain. No significant change in surface topology was observed in contrast to prior hypotheses from the literature. Based on this result obtained with the new open source tensile stage we propose an alternative hypothesis we term ‘superlamellae consolidation’ to explain the initial deformation of GO paper. The additively manufactured tensile tester tested represents cost savings of >99% compared to commercial solutions in its class and offers simple customization. However, continued development is needed for the tensile tester presented here to approach the technical specifications achievable with commercial solutions. [ABSTRACT FROM AUTHOR]

Fibre-based packaging materials are widely utilized all over the world. They have several important advantages in comparison with fossil-based packaging: biodegradability, recyclability, and renewability. However, fibre-based packaging cannot fully compete with plastic in its barrier properties. Also there are limitations regarding its shapes due to poorer formability. The deep-drawing forming process can be used for the production of advanced three-dimensional shapes from paper-based materials. Formability and related characteristics are essential for deep-drawing of paper-based materials. This paper aims to give an overview of the deep-drawing of paper-based materials with the emphasis on the experienced deformations, on the role of mechanical properties of materials in deep-drawing, and on the typical defects found in the shapes after the forming. Additionally, strategies are proposed to help mitigate common problems in deep-drawing.

Production of paper-based packaging is growing at the present moment and has great future prospects. However, the development of new packaging concepts is creating a demand for an improvement in the mechanical properties of paper. Extensibility is one of these properties. Highly extensible papers have the potential to replace certain kinds of plastics used in packaging. Extensibility is also important for the sack and bag paper grades and for runnability in any converting process. This paper reviews the factors that affect the extensibility of fibres and paper, and discusses opportunities for improving the straining potential of paper and paper-like fibre networks. It is possible to classify factors that affect extensibility into three main categories: fibre structure, interfibre bonding, and structure of the fibre network. Extensibility is also affected by the straining situation and the phase state of the polymers in the cell wall. By understanding the basic phenomena related to the elongation, and by combining different methods affecting the deformability of fibre network, extensibility of paper can be raised to a higher level. [ABSTRACT FROM AUTHOR]

Paper is mainly made up of cellulosic fibrous materials. On one hand, the nature of the fibres (softwood or hardwood) and on the other hand, their mechanical treatments severely affect the obtained porous structure. The porosity can vary from 1% to 95% according to the aimed end-use properties. Consequently, the mechanical behaviour strongly varies. Indeed, the mechanical resistance is related on the quality of fibres and the bonds between these fibres. Moreover, the mechanical behaviour of the final products is influenced by both the orientation of fibres and moisture. Consequently, it is important to better understand the moisture-induced changes of dimensions and mechanical properties of papers. Experiments were undertaken to this end. Moreover, in order to observe the fibrous microstructure of paper, experiments based on synchrotron microtomography were carried out with the help of the "European Synchrotron Radiation Facility" (ESRF). [ABSTRACT FROM AUTHOR]

Formable papers can be used as an alternative to rigid plastics for making 3D shapes for packaging applications. However, commercial use of formable paper is currently limited, due to its poor extensibility. Cellulosic fibres can be combined with polyurethanes to improve the deformability of resulting fibre-polymer composites. This work describes the effect of spray and wet-end addition of polyurethane dispersions to paper to enhance the extensibility and formability of paper. The increase in extensibility was directly proportional to the amount of polyurethane retained in the paper. Absolute improvements in extensibility were as high as 4 to 6 percentage points. Improved extensibility resulted in better formability of paper, which eventually could allow it to compete with plastic packaging in certain applications. [ABSTRACT FROM AUTHOR]

Paper honeycomb and EPE are widely used in the field of packaging protection and safety transportation. Given the cushioning and protective function of unilateral and bilateral composite layered structures (CLSs) including polyethylene foam (EPE) and paper honeycomb, this work focused on analyzing the energy absorption (EA) and compression deformation of honeycomb thickness (HT) CLS under diverse drop impact (DI) status. Experimental observation showed that the increase of HT can improve the impact resistance of EPE and its CLSs. For the CLS with the HTs of 10, 15, 20, and 25 mm, the increase of paper HT may reduce the EA at low impact energy, while enhancing the EA capability at high impact energy. However, the EA of CLSs with a large HT of 70 mm is relatively poor. For the same drop weight mass or impact energy, the stroke efficiency (SE) and specific energy absorption (SEA) of the unilateral CLS with the same HT are, respectively, increased by 39.1% and 16.2%, so the EA of the unilateral CLS is superior to the bilateral CLS. [ABSTRACT FROM AUTHOR]