Mechanical Properties and Reliability of Parametrically Designed Architected Materials Using Urethane Elastomers

Achieving multiple physical properties from a single material through three-dimensional (3D) printing is important for manufacturing applications. In addition, industrial-level durability and reliability is necessary for realizing individualized manufacturing of devices using 3D printers. We investigated the properties of architected materials composed of ultraviolet (UV)-cured urethane elastomers for use as insoles. The durability and reliability of microlattice and metafoam architected materials were compared with those composed of various foamed materials currently used in medical insoles. The hardness of the architected materials was able to be continuously adjusted by controlling the design parameters, and the combination of the two materials was effective in controlling rebound resilience. In particular, the features of the architected materials were helpful for customizing the insole properties, such as hardness, propulsive force, and shock absorption, according to the user’s needs. Further, using elastomer as a component led to better results in fatigue testing and UV resistance compared with the plastic foam currently used for medical purposes. Specifically, polyethylene and ethylene vinyl acetate were deformed in the fatigue test, and polyurethane was mechanically deteriorated by UV rays. Therefore, these architected materials are expected to be reliable for long-term use in insoles.

Experimental quantification of the impact of heterogeneous mix on thermonuclear burn

In inertial confinement fusion (ICF), deuterium-tritium (DT) fuel is brought to densities and temperatures where fusion ignition occurs. Mix of ablator material into the fuel may prevent ignition by diluting and cooling the fuel. MARBLE experiments at the National Ignition Facility (NIF) provide new insight into how mix affects thermonuclear burn. These experiments use laser-driven capsules containing deuterated plastic foam and tritium gas. Embedded within the foam are voids of known sizes and locations, which control the degree of heterogeneity of the fuel. Initially, the reactants are separated, with tritium concentrated in the voids and deuterium in the foam. During the implosion, mix occurs, leading to DT fusion reactions in the mixed region. Here we show that by measuring ratios of DT and deuterium-deuterium (DD) neutron yields for different macropore sizes and gas compositions, effects of mix heterogeneity on thermonuclear burn may be quantified and understood for the first time.

Research on Ink Absorption Effect of Adhesive on Foam Plastic Surface Coatings

The purpose of this paper is to study the influence of different adhesives and dosage on the performance of ink absorption coating and improve the quality of foam surface. In this experiment, silica was used as pigment, PVA1788, PVA1799, PVA235 and soluble starch were used as binders, and rigid polyurethane foam was used as coating object. In this experiment, a spraying method was used to coat the surface of plastic foam, UV printer was used for graphic output, and related equipment were used to test the performance of the coating. The results showed that when the ratio of adhesive (PVA1788) to pigment was 20%, the whiteness and wettability of the coating were the best. In this case, rich color range and gradation level could be obtained. With the increase of the alcoholysis of polyvinyl alcohol, the dissolution became difficult, water resistance increased, bonding force increased, film formation became better, and the contact angle of the coating prepared by the high alcoholysis of PVA as adhesive was lower. The coating with PVA235 as adhesive had the highest color density and the best comprehensive effect.

ANALISIS KONDUKTIVITAS PANAS PADA MATERIAL ALTERNATIF SEBAGAI INSULASI DINDING RUANG AKOMODASI KAPAL BERBASIS LIMBAH AMPAS TEBU DAN SERBUK KAYU

The accommodation room on the ship is used as a resting place for the crew and as a storage place for goods on the ship so insulation is needed in each room to withstand the heat propagation on the ship. One type of insulation material on a ship is mineral wool which is made from polyurethane. Polyurethane is a plastic foam that is a mixture of polyol and isocynate and one of the ingredients is polymer which can be obtained from natural materials that contain lots of cellulose such as bagasse and sawdust. the addition of sawdust and bagasse that can be done is 40% of the total volume of the mixture. Then it is carried out to get the thermal conductivity value of each mixture of sawdust, bagasse, and polyurethane with various dosing ratios on the sawdust, to further calculate the cooling load. The test results show the best conductivity value is the mixing of wood powder 0.2 gr which is 2.65 w / mk which can withstand the rate of heat up to 311.59 KW.

Numerical test on polystyrene tunnel seismic-isolation material

Stress-strain mechanical properties of polystyrene foam plastic material were tested under different loading conditions. An empirical constitutive model for describing metal materials was proposed for the polystyrene plastic foam. The static and dynamic tests results show that the ductility and watertightness of the polystyrene plastic foam are significantly improved. At the same time, in order to check its seismic-isolation property, the high-performance foam concrete as filling materials of Galongla tunnel in Tibet was simulated by FEM. The simulated results show that the polystyrene plastic foam can remarkably decrease the stress and the plastic zone in final lining, so it can effectively reduce the seismic damage of the tunnel. Considering the seismic-isolation property and low price of polystyrene plastic foam, it is a good reference for the anti-seismic design of tunnels in high intensity zones.