• Journal of Magnetics
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• v.22 no.1
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• pp.133-140
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• 2017

Split magnetic fluid sealing is a combination of magnetic fluid rotary and plane sealing. Using the theory of equivalent magnetic circuit design as basis, the author theorized the pressure resistance performance of magnetic fluid plane sealing. To determine the pressure resistance of magnetic fluid plane sealing, the author adopted the method of finite element analysis to calculate the magnetic field intensity in the gap between plane sealing structures. The author also analyzed the effect of different sealing gaps, as well as different ratios between the sealing gap and tooth and solt width, on the sealing performance of split magnetic fluid. Results showed that the wider the sealing gap, the lower the sealing performance. Tooth width strongly affects sealing performance; the sealing performance is best when the ratio between tooth width and sealing gap is 2, whereas the sealing performance is poor when the ratio is over 8. The sealing performance is best when the ratio between the solt width and sealing gap is 4, indicating a slight effect on sealing performance when the ratio between the solt width and sealing gap is higher. Theoretical analysis and simulation results provide reference for the performance evaluation of different sealing equipment and estimation of critical pressure at interface failure.

• Food Science and Preservation
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• v.4 no.1
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• pp.11-15
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• 1997

This experiment carried out to find the storage life according to the kinds of packaging material. Sheridan(Grape) which was fumigated SO2 were wrapped with polyethylenes(Bio-PE and PE) and stored at $0^{\circ}C$ under 90% RH modified condition. The resorts were summarized as follow. Natural weight loss was increased according to the storage time during the 135days storage that was only 1.0-1.7% in sealing section while 10% in non-sealing section. Abonrmal fruits were increased as the storage time was increased and it was 6.6-6.7% in sealing section while 100% in non-sealing during the 135days storage. Quality of appearance and taste are better in sealing section than non-sealing section and it was good in Bio-PE sealing section between packaging materials. Moistrue content was de creased as the storage range was increased and the decreasing rate of that during the storage was 4.9-5.2% in sealing section between treatments. During the storage range increased, the soluble solid degree was increased in non-sealing section but decreased in sealing section.

• KSTLE International Journal
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• v.3 no.2
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• pp.79-83
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• 2002

Sealing an oil-air mixture plays important roles to have an enhanced lubrication for high speed spindle. High speed spindle requires non-contact type of sealing mechanism. Current work emphases on the investigation of the air jet effect on the protective collar type labyrinth seal. To improve the sealing capability of conventional labyrinth seal, air jet was injected against through the leakage flow, It has a combined geometry of a protective collar type and an air jet type. Both of a numerical analysis by CFD (Computational Fluid Dynamics) and experimental measurements are carried out to verify sealing improvement The sealing effects of the leakage clearance and the air jet magnitude are studied in various parameters. The results of pressure drop in the experiment match reasonably to those of the simulation by introducing a flow coefficient Effect of sealing improvement is explained as decreasing of leakage clearance by air jetting. Thus, sealing effect is improved by amount of air jetting even though clearance becomes larger.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.6
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• pp.981-986
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• 2003

In order to investigate the possibility of processing of brittle material by ball impact, the effects of boundary conditions about impact damage of soda-lime glass by small spheres were evaluated experimentally. It was investigated that crack appearance developed in soda-lime glass with boundary conditions of without sealing, single-sealing and double-sealing by impact velocity. The double-sealing was most effective in the development of perfect cone than other boundary condition. In case of double-sealing condition, PVC and Polyurethane sealing were more effective in producing a perfect cone formation than other sealing materials. The impact velocity range over which perfect cones were formed was influenced by both the contact area and diameter of impact particle.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.18 no.11
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• pp.1019-1023
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• 2005

We have examined the electrical and optical characteristics of the plasma display panel produced by vacuum in-line sealing technology. In the MgO layer deposited at room temperature, after sealing at the panel temperature of $430^{\circ}C$, the luminous efficiency decreased compared with that of the panel before sealing. Moreover, firing and sustain voltage of the sealed panel increased compared with that of the panel before sealing. This was resulted from that the MgO protective layer was cracked by the softening of the dielectric layer during the sealing process. In order to avoid the MgO crack during the vacuum in-line sealing, thermally stable MgO layer or lower temperature sealing is required.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.5
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• pp.156-163
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• 2003

In order to investigate the possibility of punching process of brittle material by ball impact, the effects of sealing materials about impact damage of soda-lime glass by small spheres were evaluated experimentally. The using of sealing materials in the development of perfect cone crack was more effective than no using of sealing materials. At the sealing materials condition, in the case of 5mm-thick specimen, Copper and PMMA sealing were more effective in producing a perfect cone formation than the other sealing materials. And in the case of 8mm-thick specimen, Aluminum sealing was most effective in producing a perfect cone formation. The impact velocity range over which perfect cones were formed was influenced by both the thickness of specimen and sealing materials. By a proper selection of sealing materials, the application fur industrial technology for hole (or nozzle) punching process of brittle materials is expected.

• Restorative Dentistry and Endodontics
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• v.16 no.2
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• pp.33-42
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• 1991

The purpose of this study was to evaluate the sealing properties of the temporary filling materials used in endodontic treatment Access cavities were prepared in 135 extracted human molar teeth. Then, cotton pellets were placed in the pulp chamber until the depth of 5 mm for the temporary filling materials; Caviton, zine oxide-eugenol, double sealing (A) (stopping 15 mm + zinc oxide - eugenol, 3.5mm ) double sealing (B) (stopping 3.0 mm + zinc oxide - eugenol 2.0 mm) and gutta percha stopping. After filling the materials, the teeth were immersed in 1 % methylene blue solutions for 3 days, 1 week and 2 weeks. Then thermal cycling was performed at the temperature of $60^{\circ}C$ and $4^{\circ}C$, followed by longitudinal sections on the center of tooth. Finally, staining on the cotton pellet was evaluated. The following results were obtained. 1. Stopping showed lower marginal sealing quality than Caviton, zinc oxide - eugenol and double sealing. 2. In 1 week group, Caviton showed higher marginal sealing quality than zinc oxide-eugenol, double sealing and stopping. 3. Caviton and double sealing (B) showed a great decrease in marginal sealing quality with the increse of time. 4. Caviton had high marginal sealing quality in 3 day group and 1 week group, but in 2 week group, Caviton showed a great decrease. 5. Double sealing (B) showed fairly high marginal sealing quality in 3 day group, but decreased greatly after 1 week on.

• Tribology and Lubricants
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• v.22 no.3
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• pp.119-126
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• 2006

In this paper, the contact behavior characteristics of a primary sealing components such as a seal ring and a seal seat has been presented for a small hydro-power turbine. Using the non-linear FEM analysis, the maximum temperature, the axial displacement, radial differences between a seal ring and a seal seat, and maximum contact normal stress have been analyzed for three optimized sealing profiles in which are designed based on the FEM analysis and Taguchi's experimental method. The three primary sealing profiles between a seal ring and a seal seat are strongly related to a leakage of a water for a hydro-power turbine and wear of a primary sealing component. The computed results show that the contact rubbing area between a seal ring and a seal seat is very important for reducing a friction heating and wear in a sealing gap, and increasing a contact normal stress in primary sealing components. Based on the FEM computation, models II and III in which have a small rubbing surface of seal rings show low dilatation of primary sealing components, and high normal contact stress between a seal ring and a seal seat. Thus, the FEM computed results recommend a short contacting width of a primary sealing component for reducing a leakage and thermal distortions, and expanding a seal life. This means that a conventional primary sealing component may be switched to a reduced sealing face of seal rings.

• Structural Engineering and Mechanics
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• v.84 no.3
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• pp.337-344
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• 2022

Due to corrosion defects on the surface of the oil pipe, the sealing performance of the annular blowout preventer (BOP) decreases, and the leakage of toxic and harmful gases such as H₂S and SO₂ will threaten the safety of operators on the well. Therefore, this paper establishes the FE model for evaluating the sealing performance of BOP-oil pipe corrosion defects, which is based on the rubber large deformation theory and rubber core sealing mechanism, and designs the experiment of BOP sealing performance to verify the accuracy of the FE model. The sealing performance of BOP sealing oil pipe with corrosion defects is studied. The research results show that the sealing performance of BOP is more sensitive to the axial size of corrosion defects. With the increase of oil pipe outer diameter, the critical size of defects increases continuously. The sensitivity of radial and depth dimensions is low, When for 88.9 mm outer diameter oil pipe, the axial critical size of corrosion defect is 20 mm, the radial critical size is 16 mm and the critical depth is 2 mm. Fit the formula between the outer diameter of oil pipe and the piston increment. According to the formula, the operator can calculate the piston stroke increment required by the BOP to complete the sealing when the oil pipe is corroded.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.703-706
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• 2004

This paper deals with the various sealing conditions in a vacuum and the discharge characteristics. The MgO thin film is prepared by e-beam evaporation method. Sealing process was performed in a vacuum at panel temperature of 430 $^{\circ}C$. We find the cracks on the MgO film surface, which results in higher discharge voltage and lower luminous efficiency. The vacuum in-line sealing technology does not require additional annealing process but induces the MgO cracks because of the high temperature sealing cycle in a vacuum. Therefore we modify the vacuum in-line sealing cycle which the MgO cracks are not found and the good characteristics of plasma displays are found in higher sealing pressure at sealing temperature of 430 $^{\circ}C$.