Fabrication of industrially valuable PLA based coated abrasive and packaging products are made using bio-polymeric blends of PLA-PEG without involving the use of hazardous halogen based solvents, such as, chloroform and dichloromethane. Accordingly, an attempt has been made in our study to substitute a relatively less harmful ethyl acetate (EA) solvent in place of the toxic halogenated solvents to dissolve both PLA and PEG polymer blends to produce an environmentally safe PLA-PEG coating and film formulation in EA. This attempt in turn eliminates and replaces the use of non-degradable polymer coatings, (such as, acrylates, PVC, and synthetic latex) on Kraft paper thereby contributing to sustainability and environmental safety besides reduction in waste disposal to realize a cleaner environment. PLA is a hard and brittle polymer, which restricts its unexplored industrial user applications. On the other hand, PEG toughens the brittle PLA due to its plasticizing action. Hence, PLA-PEG polymer blends were prepared using increasing percentage of PEG content systematically from 5% to 25% and the % of PEG in PLA was optimized to 10% to get the maximum toughening effect in PLA-PEG formulation, which is ascertained by differential scanning calorimetry analysis. FTIR analysis confirmed the possible interaction that occurred between PLA and PEG, due to which a shift in vibration frequency of the PLA carbonyl group is observed. The other important test results from mechanical properties, contact angle, surface roughness, Cobb values, WVTR, and SEM analysis support to reveal that PLA-PEG (10%) blend is the best coating and film forming material on Kraft paper for the fabrication of industrially valuable both coated abrasive and packaging products to demonstrate its dual purpose applications.

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Laminate composites are widely used in automotive, aerospace, and increasingly in consumer industries, due to their reduced weight and superior structural properties. However, structural analysis of complex laminate structures remains challenging. 2D finite element methods based on plate/shell theories may be accurate and efficient, but they generally do not apply to the whole structure and require identification and preprocessing of the regions where the underlying assumptions hold. Fully automated structural analysis using solid 3D elements with sufficiently high order basis functions is possible in principle, but is rarely practiced due to the significant increase in the cost of computational integration over a large number of laminate plies.We propose a procedure to replace the original laminate by much simpler new virtual material models. These virtual material models, under the usual assumptions made in lamination theory, have the same constitutive relationship as the corresponding 2D plate model of the original laminate, but require only a small fraction of computational integration costs in 3D FEA. We describe implementation of 3D FEA using these material models in a meshfree system using second order B-spline basis functions. Finally, we demonstrate their validity by showing agreement between computed and known results for standard problems. Figure 1: Figure shows a structure made of 3 laminates analyzed using different finite element methods (a) Plate/shell element (b) Element of 3D conforming mesh (c) Element of a 3D non-conforming mesh (d) Element of a non-conforming mesh with curved laminate inside.to fully automatic, are generally parallel and unidirectional and, therefore, result in plies which are anisotropic in nature. Material properties are customized by varying fiber angle within each ply, controlling the number of plies, and adding additional materials between plies such as cores and fillers. The presence of numerous plies, however, leads to complex geometry and material distribution in laminate structures, and, therefore, structural analysis of laminates by treating each ply layer individually is prohibitively expensive. The common practice is to assume that the layers are permanently fused together and ignore any fluctuation in stress-strain fields at the interfaces of layers [4,3,5,6]. These assumptions allow to approximate laminate's global behavior as that of a plate or a shell. Interlaminar stresses and strains may be significant in boundary regions and regions of discontinuities [7] where full three-dimensional and/or layered methods should be used, but the plate/shell assumptions give sufficiently accurate stress and strain estimates for regions away from those regions [8].In this paper, we will show that the same plate/shell assumptions, when applicable, may be used within a general 3D finite element analysis to dramatically speed up the analysis procedure.Structural analysis of laminates can be carried out using different finite element methods, and some of them are illustrated for ...

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Bonded multi-material assemblies arise frequently in design, manufacturing, architecture, and materials design. It is a common wisdom that finite element analysis of such assemblies usually requires all components to be represented by compatible finite element meshes; application of meshfree methods in such situations is often considered problematic due to the need to impose additional interface conditions. Neither approach scales to deal with realistically complex models arising in many applications. We propose a simple extension of meshfree analysis on a non-conforming mesh for linear structural analysis of such multimaterial assemblies. The method is simple, can be implemented within most FEA packages and does not require either compatible meshing or complex interface boundary conditions. Our numerical experiments demonstrate that computed results are in good agreement with known analytical and computational results for well studied multi-material bonded assemblies (lap and butt joints). We also demonstrate application of the proposed method to realistically complex assembly of a mounted sculpture that cannot be easily analysed by other methods.