Papers by Keyword: TPU

Abstract: Architected metamaterials fabricated by additive manufacturing offer deterministic geometries and tunable mechanical properties that can outperform conventional foams in energy absorption and impact mitigation. In this work, origami honeycomb and plate-lattice metamaterial concepts are unified within a common, quantitatively characterised metamaterial. An optimization-based design approach is employed to maximise absorbed energy while keeping the peak stress below a predefined threshold, using metamaterial geometric parameters as design variables. The objective function is evaluated through post-processing of Abaqus compression simulations on automatically generated designs. Owing to the high computational cost, the optimisation is performed using an evolutionary algorithm with a limited number of evaluations, yielding a best-performing design rather than a global optimum. Despite this limitation, the results elucidate the critical roles of buckling in limiting initial peak stress and of contact in enhancing post-peak energy absorption, and they highlight the significant potential for further performance gains through expanded design space exploration.

Abstract: Nowadays, there is a spike in 3D printing and additive manufacturing technology all over the world. Starting from the prototype state to the final production process, a high demand is noticed due to the fact that this technology is rapid, economical and good-fit for finding out the mechanical behavior of the material and the structure. Thermoplastic polyurethane (TPU) is widely used in automotive industry, sport industry, medical industry, even in footwear industry. High abrasion resistance, shear strength, elasticity with low-temperature performance make TPU widely used and so important. In this study, we focused on the effect of infill pattern and density in mechanical behavior of 3D printed TPU part. We controlled the density and pattern both resulting in changing mechanical properties, helping us reduce the use of material, cost and production time accordingly. It is necessary to prepare a database on the test results, which can help us to understand the parameters related to internal structure or infill pattern of the material.

Abstract: Fruit skins are waste and natural fibers which are processed from it can be used as filler material in polymer composites. These natural fibers are surely inexpensive, non-toxic and environmentally friendly. In the other hand, natural fibers are chemically hydrophilic and absorb water. Their nature which are rich cellulose making it hydrophilic in nature. Besides their nature to water, the ability of natural fibers to absorb oil also interesting to be studied. In this paper, natural fibers from several types of fruit skin were used as filler in thermoplastic polyurethane (TPU) composites. The fibers from pineapple skin, coconut shell, coconut husk, corn cob, rambutan, mangoesteen and banana with the percentage of 15% and 20% were incorporated with TPU through melt mixing technique. Every type of natural fiber will absorb oil and water at different rate, as well as the effect of filler content in the composite. Overall, the absorption of water and oil increased its percentage when the filler content increases. Rambutan, pineapple and banana absorb more water than others at 20% filler content in the TPU. Pineapple and rambutan also tend to absorb more engine oil.

Abstract: The blends of ethylene vinyl acetate (EVA) and thermoplastic polyurethane (TPU) were prepared by means of blending. The mechanical properties of EVA/TPU blends and thermal stability of the extrudates were investigated. The results show that the toughness of EVA/TPU has been improved after adding TPU into EVA, and doesn’t affect the thermal stability of material.

Abstract: The manufacture of a rotational shaft seal (soft component) adhesively bonded to a polymeric housing (hard component) is not state of the art. The paper approaches the feasibility to shape such hard-soft composite employing assembly injection molding technique.

Abstract: Graphene nanoplatelets (GNP) and thermoplastic polyurethane (TPU) have been often used as filler and matrix, respectively, to produce composites. In this work, TPU/GNP composites were prepared via a melt blending method. The mechanical properties and frictional properties of TPU/GNP composites were investigated. Because the GNP is very expensive, we investigated to use graphite as the filler, to use PP-g-MAH as the compatibilizer and examined the characteristics of the prepared composites. Frictional properties and mechanical properties of GNP/TPU composites remarkably improve when adding PP-g-MAH as the compatibilizer. Tensile strength of composite containing 10wt % of GNP and 10wt% PP-g-MAH was measured as 25.5MPa. When the graphite was used to replace for GNP, the frictional properties of composites decreased, but the mechanical properties improved.

Abstract: Poly (lactic acid) (PLA) elastic fibers were prepared by melt spinning using Thermoplastic polyurethane (TPU) as a toughing agent and PLA-g-MA(Maleic anhydride) as a compatibilizer. Thermal properties and thermal stability of PLA/TPU composites, as well as the cross section morphology and mechanical properties of fibers were studied in the present investigation. DSC results showed that PLA was immiscible with TPU. In addition, the incorporation of TPU decreased the melting enthalpy of PLA/TPU composites. TG results indicated that the initial degradation temperatures of composites were also decreased by the appearance of TPU, and it decreased by 9°Cwhen TPU content was up to 20wt%. FESEM results confirmed that strong interactions were existed between PLA and TPU phases, which were benefit for the improvement of PLA/TPU fibers’ mechanical properties. Results of tensile testing demonstrated that TPU could improve the toughness of fibers effectively and the elongation-at-break of fibers increased from 2.2% of PLA to 203.9% of PLA/TPU.

Abstract: Thermoplastic polyurethane (TPU) has been used to toughen Poly (3-hydroxybutyrate-co-4-hydroxybutyrate) (P34HB) and increase its cold-resistance. The compatibility of P34HB/TPU blends was predicted by solubility parameter, then investigated by appearance and transparence, Dynamic Mechanical Analysis (DMA) and Scanning Electron Microscopy (SEM) analysis. The P34HB/TPU was found to be a partly compatible system. The appearance and transparence of P34HB/TPU blends were smooth and non-transparent. The DMA showed that the glass transition temperature of P34HB was decreased with the increase of TPU content. The SEM photos showed that the morphology of the P34HB/TPU blends were the sea island structure.

Abstract: In this paper, two kinds of adhesives were introduced into the treatment on polyester fabrics, and all achieved after calendered conjointly with TPU. Then the standing against of water was investigated too.

Abstract: In order to recycle the waste peanut hull and TPU(thermoplastic urethanes), the composite made from peanut hull powder which was used as reinforcing material and TPU which was used as matrix material by the method of blending and hot pressing was discussed. The parameters of molding process were designed by orthogonal experiment. The tensile property, bending property and impact property of composite materials were tested in this study. The molding process parameters were optimized with the methods of range analysis and single factor analysis. The results showed that the optimum conditions were given as followings: concentration of peanut hull powder was 60%, hot pressing temperature was 170°C, hot pressing pressure was 12Mpa, and hot pressing time was 5min. Under above conditions, excellent mechanic properties were achieved, which were that tensile strength was 19.63MPa, bending strength was 25.74MPa, impact energy absorption was 1.33 KJ/m2.