Academic literature on the topic 'Orthogonal pressing process'

In this paper, the basalt fiber/polylactic acid composites were prepared by laying-up hot-pressing process, using PLA sheet as the matrix material and basalt fiber fabrics as the reinforced material, besides, the mechanical properties were studied and the parameters of hot-pressing were optimized. PLA mass fraction, heat pressing temperature, heat pressing pressure and heat pressing time were selected as the four main influence factors and tensile strength and bending strength were taken as the test indexes, the best processing conditions: PLA mass fraction 63%, Heat pressing temperature 195 °C, Heat pressing pressure 7MPa, Heat pressing time 10min were optimized through orthogonal experiment and range analysis. The significance of the study was providing theoretical guidance for the further development of high-performance basalt fiber composites.

In order to improve the quality of ADC12 alloy billets prepared by Chips Solid Pressing (CSP) process, the effects of pressing temperature, pressure and packing time on the density of ADC12 alloy billets were investigated by using the orthogonal array and multiple nonlinear regression analysis. The results indicated that the pressing temperature has the greatest effect on the density of the billets, and it is followed by pressing pressure and packing time. The optimized process parameters, including a pressing temperature of 250oC, pressing pressure of 640MPa and packing time of 45 seconds, can be used to obtain the most compact billets of ADC12 alloy prepared by CSP process.

Orthogonal experiment of four factor and three level has been adopted, through the process analysis of the various factors on mechanical properties, the best process conditions of soybean stalks particleboard are chosen as: density is 0.7g/cm3, glue content is 12%, and hot pressing time distribution is 3+4 minutes, hot pressing temperature is 175°C. The Ef (the dynamic elastic modulus of NDT) of soybean stalks particleboard has been examined by flexural vibration method of FFT(Fast Fourier Transform), the regression between Ef and MOE(modulus of elasticity), MOR(modulus of rupture) is significant and existing high relevance degree, so using FFT method for NDT of composite materials is feasible.

By analysis of manufacturing performance of corn stalk, and taking practical processing technics of particle board in consideration, this paper set strawboard density, adhesive consumption, hot-pressing temperature and hot-pressing pressure as variable factors, set prepressing pressure, prepressing time, shaving shape and moisture content of raw material as fixed factors, exploring the optimal combination of process parameters through orthogonal experiments.

Flax yarn and PP filament can be made into flax/ pp lapping yarn. Weaving with the lapping yarn, and finally can crank the fabric into PP/ flax composite by hot pressing. Research on the thickness of composite material and the peeling properties of the composite material, we analyzed the correlative factors about the producing technics of composite by orthogonal experimental method. The results showed that the material’s thickness and the technics are the main influencing factors of the wettability, and forecast the technics of composite molding process to get the best wettability properties.

A new way of severely deforming ductile metals in order to refine their microstructure is proposed. It is called incremental angular splitting and originates from the idea of orthogonal cutting. It is intended to intensify plastic deformation in the cutting zone and lead to faster refinement of the microstructure. A laboratory experiment carried out on Al 1070 has proved the technical feasibility of the process. As the first indication of process capability, micro hardness measurements have been used to compare incremental angular splitting and incremental equal channel angular pressing.

This paper proposes a gel-formed abrasive tool to address the problem of abrasive agglomeration in a traditional hot-pressing abrasive tool. The effect of Polyimide resin content on the mechanical properties of the gel abrasive tools were tested, and a comparison of the mechanical properties of the gel abrasive tool and the hot-pressing tool was conducted. An orthogonal experiment was conducted to explore the best combination of machining parameters. A polishing experiment of sapphire was conducted to compare the processing effect of the gel abrasive tool and hot-pressing tool. The results from testing the mechanical properties showed that the tensile, flexural, and impact strength of the gel abrasive tool was better than that of the hot-pressing abrasive tool. The results of the orthogonal experiment showed that the best process parameters of the gel abrasive tool were a spindle speed of 900 rpm, a feed rate of 8 μm/min, and a grinding depth of 16 μm. The polishing experiment showed that the gel abrasive tool had a better processing effect on sapphire. The sapphire surface processed by the gel abrasive tool had no deep scratches, and an ultrasmooth surface could be obtained after chemical mechanical polishing (CMP).

A new model of the material flow in rotary friction welding of tubes is proposed. The material flow proposed is based on 3D microcomputer tomography scans of welds performed with tungsten tracers. The tracers indicate a bifurcation of flow into two deformation paths. The material in Path 1 interacts with the weld interface and exhibits large azimuthal flow. The material in Path 2 transitions from axial to primarily radial flow with little or no azimuthal flow. The directional transition in this path is compared to orthogonal machining and equal channel angular pressing. The process to estimate the variables needed to calculate strain and strain rates using the equations from orthogonal machining and equal channel angular pressing is defined. Strain and strain rate in Path 2 are dependent upon feed rate and upset and decrease throughout the welding process. The strain rate is higher than previously reported for rotary friction welding as a result of the deformation model proposed.

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.

In this study corn husk used as raw material, and achieved corn husk fiber through degumming properly. Then degradable fiberboard can be obtained with husk fiber and polylactic acid particles through blending and hot pressing. Taking mass fraction and length of corn husk fiber, hot-pressing time and temperature as factors, and taking tensile, bending and impact strength as index, through the L9 (34) orthogonal testing and range analyzing and achieved the optimal process parameters is: corn husk fiber mass fraction is 50%, corn husk fiber length is 10 mm, hot pressing time is 6 min, hot pressing temperature is 180 °C. Under the optimal process condition, a optimal fiberboard is obtained, whose tensile strength is 69.32 MPa, bending strength is 90.26 MPa, impact strength is 18.5 KJ/m2. The conclusion of this paper provides the theoretical guidance for the reuse technology of corn husk fiber.

The scientific and clinical need to advance understanding of the processes related to Hispanic acculturation and its impacts is pressing. This chapter articulates how acculturation stress and related specific stressor events occur within distinct life domains or contexts. New research is juxtaposed to previous research that demonstrated how acculturation stressors cluster in unique, orthogonal, and independent life domains among both adult and adolescent Hispanics. This chapter refers to contexts of acculturation stress as spheres of life or domains that entail social and psychological interactions with the dominant, receiving culture. New research is presented on the relationship between acculturation stress context among adult Hispanics and mental health indicators. Understanding the contexts in which acculturation-related stress can impact Latinos is critical to health and behavioral health programming, where such information can assist in the development, adaptation, and tailoring of prevention and interventions that are more acceptable and relevant for this growing population.

During the last years, many research efforts in e-learning were focused on developing new content delivery algorithms able to improve the quality of the learning process from content distribution point of view. This is a pressing problem as an increasing number of users are accessing learning content from mobile devices via wireless networks. E-learning involves multiple activities (i.e. web browsing, video and audio streaming, interactive voice calls and ftp background traffic exchange) and various applications that are generating a rich traffic mix. Managing traffic flows is a difficult problem, especially when they are delivered over wireless networks. This is because wireless technologies have limited radio resources and are highly susceptible of being affected by environmental factors, traffic load, number of clients and their mobility patterns. Additionally delivering multimedia traffic with large bandwidth requirements and high sensitivity to loss and delay variations in these wireless environments at high quality levels constitutes significant challenge. Moreover if the end goal is learning and involves users with various profiles, there is an important pressure in developing excellent adaptive solutions to distribute the multimedia content. The paper will describe in detail a novel solution for adaptive multimedia content delivery over wireless networks, the Dynamic Quality-Oriented Adaptation Scheme (DQOAS) which focuses on mobile e-learning. The proposed algorithm concentrates on performing multimedia content management in accordance with end-user learning profile, including their preferences and network conditions. By using DQOAS the end-user quality of experience (QoE) during learning process is improved, as shown in previous papers that investigates the benefits of the algorithm when IEEE802.11 networks are used. The paper presents also the behavior of DQOAS for multimedia content delivery in next generation networks, and in particular over Long Term Evolution (LTE) networks. LTE is an all-IP network technology standardised by the 3rd Generation Partnership Project (3GPP) in Release 8 which uses new multiple access schemes on the air interface. Orthogonal Frequency Division Multiple Access (OFDMA) is used in the downlink and Single Carrier Frequency Division Multiple Access (SC-FDMA) is employed in the uplink to fulfil all the ambitious requirements for data rate, spectrum efficiency, latency, and capacity. Another important technique used is Multiple Input Multiple Output (MIMO) that involves using multiple transmitters and receivers to achieve higher bit rates and improved coverage. An important aspect in LTE is Quality of Service (QoS) support. The 3GPP QoS concept is based on traffic differentiation and prioritization of data flows, using network-initiated bearers in conjunction with simple QoS profiles based on QoS Class Identifiers (QCI). This paper proposes a new QoS delivery parameter mapping which complements LTE QoS class mapping, most beneficial for the case of e-learning traffic mix, in order to obtain higher end-user QoE levels when used in conjunction with DQOAS. The proposed solution improves the overall QoE for the end-user. The paper will be structured as follows. Section II will present the technical aspects and the studies performed by researchers regarding LTE QoS parameters and scheduling in case of traffic mix connections for both downlink and uplink. Section III will describe the DQOAS algorithm. Section IV will present the functioning of the algorithm followed by test results in section V. Conclusions will be drawn in section VI.