Trends in the Development of Machinery and Associated Technology ” TMT 2008 , Istanbul , Turkey , 26-30 August , 2008 PERFORMANCE CHARACTERISTICS OF POLYURETHANE FOAM GASKETS
In this study, the performance characteristics of polyurethane foam gaskets have been investigated experimentally in a flanged joint system. Accordingly, it is possible to be compared the test results of polyurethane foam gaskets which have different properties by using this designed testing apparatus. Samples are prepared as foam in place method by using polyurethane material. Whilst samples have been prepared, mixing ratio of 2 different materials, weight in grams value of foamed gasket in 1 second (g/s) and temperature of foamed surface are taken variable parameters; ambient temperature, same type material and polyurethane foam gasket machine foaming velocity are taken constant parameters. The results obtained from the experiment are targeted to use by selecting the optimum gasket according the operating conditions.
A New Concept of Static Rubber Gasket for Sealing Rough Surface
This paper reports on a new concept for static seal designs taking into consideration the surface roughness of sealing surfaces. The concept focuses on fluid penetration from the interstices between the seal and counterface caused by surface roughness. In the study, we investigated the relation between the leakage and surface roughness of the sealing surface of the elastomer seal. At the same time, we also analyzed the contact state of the elastomer seal based on the equations of Ishiwata et al. on deformation of elastomer surface into rough surfaces [1]. The micro-leakage testing machine (SMLA) developed by the authors was used to measure micro-leakage at high precision and in a short time [2]. The results showed that the sealing phenomena were related to the ratio of seal surface contact pressure P s / elastic modulus of seal E, determined by the compression ratio of seals, and does not depend on the chemical structure and hardness of the elastomer used. Furthermore, we reviewed the equations for predicting leakage based on the shape and elastic modulus of the elastomer seal, surface roughness of the seals and counterfaces, and using conditions, and found that these can be simulated.
A New Vacuum Pressure Infiltration CFRP Method and Preparation Experimental Study of Composite
In order to prepare a carbon-fiber-reinforced polymer composite (CFRP) with ideal microstructure and properties, a new vacuum pressure infiltration CFRP method is proposed based on an analysis of existing CFRP preparation process methods. Research on composite material preparation systems was carried out by using this new method principle. The system mainly includes a fiber pre-forming module, a vacuum heating infiltration module, a hot-press curing molding module, and a data acquisition control module. Under the conditions of natural curing at 0 MPa + 6 h + 25 °C, vacuum heating curing at –0.05 MPa + 30 min + 80 °C, and hot-press curing at 0.7 MPa + 5 min + 50 °C, a two-dimensional (2D) CFRP with excellent microstructure and properties was successfully prepared. Observing the microstructure of the prepared composite material, it can be found that the inside of the composite material was sufficiently and uniformly infiltrated, and common preparation defects such as holes and delamination were effectively controlled. Through the performance test, the bending strength of the material reached 790 MPa.