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Analysis of the Pressure Distribution for Press Shoe considering Partially Changed Curvature of Bearing Surface

  • Park, Sang-Shin;Park, Young-Ha;Lee, Young-Ze;Han, Man-Cheol
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.123-124
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    • 2002
  • A press shoe is an element of a machine for squeezing water from wood pulp in the field of manufacturing paper. This is used to compress the pulp enveloped by felt sheet with a large roller. The squeezing force is made by hydraulic pressure. The press shoe has a mechanism similar to a partial hydrostatic bearing. The pressure profile between press shoe and roller affects their squeezing ability, and partial peak pressure can tear the wet pulp. The curvature of the surface of press shoe varies to reduce the peak pressure and increase the mean pressure simultaneously. Therefore, the prediction of pressure distribution considering partially changed curvature of hydrostatic bearing is very important for designing the press shoe. In this study, the difference formulation of Reynolds' equation for partial hydrostatic bearing is by direct numerical method and a computer program to calculate the pressure distribution is developed. We investigate the effect of partially changed curvature of bearing surface on the pressure distribution. Other design parameter for hydrostatic bearing such as depth of pocket and relative velocity are also studied.

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Analysis of the Pressure Distribution for Press Shoe considering Partially Changed Curvature of Bearing Surface

  • Park, Sang-Shin;Park, Young-Ha;Lee, Young-Ze;Han, Man-Cheol
    • KSTLE International Journal
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    • v.3 no.2
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    • pp.90-94
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    • 2002
  • A press shoe is an element of a machine for squeezing water from wood pulp in the field of manufacturing paper. This is used to compress the pulp enveloped by felt sheet with a large roller. The squeezing farce is made by hydraulic pressure. The press shoe has a mechanism similar to a partial hydrostatic bearing. The pressure profile between press shoe and roller affects their squeezing ability, and partial peak pressure can tear the wet pulp. The curvature of the surface of press shoe varies to reduce the peak pressure and increase the mean pressure simultaneously, Therefore, the prediction of pressure distribution considering partially changed curvature of hydrostatic bearing is very important far designing the press shoe. In this study, the difference formulation of Reynolds equation far partial hydrostatic bearing is derived by direct numerical method and a computer program to calculate the pressure distribution is developed. We investigate the effect of partially changed curvature of bearing surface on the pressure distribution. Other design parameter far hydrostatic bearing such as depth of pocket and relative velocity are also studied.

Physical Properties of Hybrid Poplar Flakeboard Bonded with Alkaline Phenolic Soy Adhesives

  • Yang, In;Kuo, Monlin;Myers, Deland J.
    • Journal of the Korean Wood Science and Technology
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    • v.33 no.5 s.133
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    • pp.66-75
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    • 2005
  • Soybean-based adhesives have recently been reconsidered as alternatives to petroleum-based adhesives due to the uncertainty of availability of petrochemical products and the increased demand for wood adhesives. This study was conducted to investigate the adhesive properties of alkaline phenolic soy (APS) resin for hybrid poplar flakeboard. The APS resin was formulated by crosslinking an alkaline soy flour hydrolyzate with lab-prepared PF resin in the soy hydrolyzate to PF resin weight ratios of 70/30, 60/40, and 50/50. The APS resins were used to fabricate homogeneous hybrid poplar flakeboards with different resin solid levels (5%, 7%, and 9%), press temperatures (175 and $200^{\circ}C$), and press times of 8 and 10 minutes. The IB, wet MOR, and dimensional stability properties of board improved with increasing press time, press temperature, and PF level in APS resins. Increasing press time can be used to offset poor IB strength associated with a 9% resin solid level and the excessive moisture content in the mat. The following conditions were concluded to meet the requirements of the CSA standard for exterior-grade flakeboard: a 50% PF level, a 5% resin content, a $200^{\circ}C$ press temperature, and an 8 minute press time.

A Study on the Design and Measurement of Pin Press-Fit Device for Fastening Differential Gear Case and Pinion Shaft (Differential gear case와 피니언 샤프트 체결을 위한 핀 압입 장치설계 및 측정에 관한 연구)

  • Jang, T.H.;Gwon, J.U.;Eum, J.H.;Kim, J.A.;Kim, T.G.
    • Journal of the Korean Society for Heat Treatment
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    • v.34 no.1
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    • pp.25-30
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    • 2021
  • The differential gear system is a device designed to distribute the driving force of both vehicle wheels and control the rotational speed when the vehicle turns on a curve. The differential device consists of a differential gear case, a ring gear, and a pressure ring. A differential pinion gear and side gear are mounted on the differential pinion shaft inside the differential gear case. In this study, a pin press-fitting device that mounts the pinier gear and side gear to the differential pinion shaft in the differential gear case was designed, and a jig device for pin press-fitting using servo press was developed. In addition, by precisely measuring the pin press-in load and press-in distance according to the pin hole diameter of the differential gear shaft, the optimization of the pin pressin process was established.

T1 Measurement in PRESS

  • Kang, Sei-Kwon;Choe, Bo-Young;Suh, Tae-Suk;Lee, Hyoung-Koo
    • Proceedings of the KSMRM Conference
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    • 2001.11a
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    • pp.116-116
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    • 2001
  • Purpose: PRESS is one of the representative sequences in MRS, but still, we do not have the formul describing the steady state magnetization of it. So, we derive the equation of th magnetization as a function of the echo time and the repetition time, and compare it wit phantom experiments. Method: PRESS consists of three 180 pulses and the additional crusher gradients whic destroy the unwanted coherences of the magnetization. Using the simple vector model, w derive a formula which describes the behaviour of the magnetization In PRESS and compa the results with the phantom experiment. Also, we explore the results of the T1 from STEAM, PRESS and the simple exponential.

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A Case Study of an Optimum Lot Size of Press Line (프레스 라인 적정 로트 크기의 결정에 관한 사례 연구)

  • Kim, Yearn-Min
    • IE interfaces
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    • v.24 no.3
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    • pp.241-247
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    • 2011
  • This paper develops a mathematical model which searches an optimum lot size of a press line, and applies this model to the scheduling of the press line. This mathematical model is not a widely studied cost model but a model which considers the utilization of the press line under a lean production system. In this paper, the optimum lot size is a minimum lot size which does not exceed the total work time of the press line. A production volume and the priority of the production in the press line are adjusted using this optimum lot size. A mathematical model developed in this paper will allow determining the optimum lot size easily in case of variable production environments such as an introduction of a new product and a fluctuation of production volume of each item. Therefore, our model will make a better scheduling of the press line and will enhance the utilization of it.

Fatigue Strength Evaluation of Adhesive Bonded and Mechanical Pressed Joints of Cold Rolled Steel Sheet (냉간압연강판 접착 및 기계적 프레스 접합부의 피로강도 평가)

  • Kim, Ho-Kyung
    • Journal of the Korean Society of Safety
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    • v.25 no.1
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    • pp.1-8
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    • 2010
  • The tensile and fatigue experiments were conducted with tensile-shear specimens for investigating the strength of adhesive bonded and mechanical press joints of SPCC steel sheet used in the field of the automobile industry. The optimal punch press force was evaluated 50kN for combining epoxy adhesive bonding and mechanical press joining with a diameter of 8.3mm using SPCC sheet with a thickness of 0.8mm. The combining epoxy adhesive bonding and mechanical press joining exhibits the maximum tensile force of 750N. The fatigue strengths of the combination of adhesive bond and mechanical press joint and pure adhesive joint were evaluated 370N and 320N at 106cycles, respectively. These values correspond to 22% and 20% of their maximum tensile forces, respectively. However, the fatigue strength of the combination of adhesive bond and mechanical press joining was much lower than that of pure mechanical press joining.

In vitro Fermentation, Digestion Kinetics and Methane Production of Oilseed Press Cakes from Biodiesel Production

  • Olivares-Palma, S.M.;Meale, S.J.;Pereira, L.G.R.;Machado, F.S.;Carneiro, H.;Lopes, F.C.F.;Mauricio, R.M.;Chaves, Alex V.
    • Asian-Australasian Journal of Animal Sciences
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    • v.26 no.8
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    • pp.1102-1110
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    • 2013
  • Following the extraction of oil for biodiesel production, oilseed press cakes are high in fat. As the dietary supplementation of fat is currently considered the most promising strategy of consistently depressing methanogenesis, it follows that oilseed press cakes may have a similar potential for $CH_4$ abatement. As such, this study aimed to characterise the nutritive value of several oilseed press cakes, glycerine and soybean meal (SBM) and to examine their effects on in vitro ruminal fermentation, digestion kinetics and $CH_4$ production. Moringa press oil seeds exhibited the greatest in sacco effective degradability (ED) of DM and CP (p<0.05). In vitro gas production (ml/g digested DM) was not affected (p = 0.70) by supplement at 48 h of incubation. In vitro DMD was increased with the supplementation of glycerine and SBM at all levels of inclusion. Moringa oilseed press cakes produced the lowest $CH_4$ (mg/g digested DM) at 6 and 12 h of incubation (p<0.05). The findings suggest that moringa oilseed press cake at 400 g/kg DM has the greatest potential of the oilseed press cakes examined in this study, to reduce $CH_4$ production, without adversely affecting nutrient degradability.

A Study on the Dynamic Stability of Heavy Press Considering Rotational Speed (회전 속도를 고려한 대형 프레스의 동적 안정성에 관한 연구)

  • Shin, Min Jae;Kim, Chae Sil;Keum, Chang Min;Kim, Jae Min
    • Journal of the Korean Society for Precision Engineering
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    • v.33 no.8
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    • pp.623-628
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    • 2016
  • This article describes the determination of the dynamic stability for a heavy press, particularly considering rotational speed. A finite element model of the driving parts for the heavy press was generated. We also applied boundary conditions and dynamic loads considering the driving conditions. Modal analysis was conducted using the finite element construction model. Therefore, no resonance was identified with the comparison between the results of the modal analysis and vibration excitation frequency by the gear tooth. In addition, the stress distribution of the driving parts for press was determined using transient analysis. As compared to the yield strength of the material, the dynamic stability the heavy press was confirmed.

Virtual Manufacturing for an Automotive Company(VII) : Construction and Application of a Virtual Press Shop (자동차 가상생산 기술 적용(VII) : 프레스 디지털 가상공장의 구축과 활용)

  • Kuk, Seung-Ho;Lee, Sang-Seok;So, Soon-Il;Noh, Sang-Do;Kim, H.S.;Shim, K.B.;Kim, J.Y.
    • IE interfaces
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    • v.21 no.3
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    • pp.322-332
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    • 2008
  • Digital Virtual Manufacturing is a technology to facilitate effective product developments and agile productions by digital model representing the physical and logical schema and the behavior of real manufacturing system, and it includes product, resources, processes and plant. For successful applications of this technology, a digital virtual factory as a well-designed and integrated environment is essential. In this research, we constructed a sophisticated digital virtual factory of a Korean automotive company's press shop. For efficient constructions of a digital virtual factory useful to kinematic simulations and visualizations, we analyzed entire business process and detailed activities of press engineering. Also, we evaluated geometries, structures, characteristics and motions of a plant and machines in press shop. The geometric model and related data of a virtual press shop are built and managed by a modeling standard defined in this paper. The virtual manufacturing simulation of press machines is conducted to evaluate kinematic motions, cycle time and locations of components using geometric models and related data. It's for interference checks and productivity improvements. We expect that this virtual press shop helps us to achieve great savings in time and cost in many manufacturing preparation activities in the new car development process of automotive companies.