Effect of wall slip on blown film thickness distribution

2003 ◽  
Vol 43 (11) ◽  
pp. 1788-1797 ◽  
Author(s):  
Hiroyuki Higuchi ◽  
Mikio Sato ◽  
Kiyohito Koyama
Keyword(s):  
Film Thickness ◽  
Thickness Distribution ◽  
Wall Slip ◽  
Blown Film

scholarly journals Controlling Film Thickness Distribution by Magnetron Sputtering with Rotation and Revolution

Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 599
Author(s):  
Handan Huang ◽  
Li Jiang ◽  
Yiyun Yao ◽  
Zhong Zhang ◽  
Zhanshan Wang ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Film Thickness ◽  
Multilayer Film ◽  
Thickness Distribution ◽  
Parabolic Cylinder ◽  
Particle Model ◽  
Planetary Motion ◽  
X Rays ◽  
X Ray ◽  
Sputtering System

The laterally graded multilayer collimator is a vital part of a high-precision diffractometer. It is applied as condensing reflectors to convert divergent X-rays from laboratory X-ray sources into a parallel beam. The thickness of the multilayer film varies with the angle of incidence to guarantee every position on the mirror satisfies the Bragg reflection. In principle, the accuracy of the parameters of the sputtering conditions is essential for achieving a reliable result. In this paper, we proposed a precise method for the fabrication of the laterally graded multilayer based on a planetary motion magnetron sputtering system for film thickness control. This method uses the fast and slow particle model to obtain the particle transport process, and then combines it with the planetary motion magnetron sputtering system to establish the film thickness distribution model. Moreover, the parameters of the sputtering conditions in the model are derived from experimental inversion to improve accuracy. The revolution and rotation of the substrate holder during the final deposition process are achieved by the speed curve calculated according to the model. Measurement results from the X-ray reflection test (XRR) show that the thickness error of the laterally graded multilayer film, coated on a parabolic cylinder Si substrate, is less than 1%, demonstrating the effectiveness of the optimized method for obtaining accurate film thickness distribution.

scholarly journals Interferometric Instrument for Thickness Measurement on Blown Films

Photonics ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 245
Author(s):  
Michele Norgia ◽  
Alessandro Pesatori
Keyword(s):  
Film Thickness ◽  
Temperature Compensation ◽  
Close Contact ◽  
Thickness Measurement ◽  
The Novel ◽  
Blown Films ◽  
Low Coherence ◽  
Real Time Measurement ◽  
Blown Film ◽  
Standard Techniques

Real-time measurement of plastic film thickness during production is extremely important to guarantee planarity of the final film. Standard techniques are based on capacitive measurements, in close contact with the film. These techniques require continuous calibration and temperature compensation, while their contact can damage the film. Different optical contactless techniques are described in literature, but none has found application to real production, due to the strong vibration of the films. We propose a new structure of low-coherence fiber interferometer able to measure blown film thickness during productions. The novel fiber-optic setup is a cross between an autocorrelator and a white light interferometer, taking the advantages of both approaches.

An Accurate Solution of the Gas Lubricated, Flat Sector Thrust Bearing

1977 ◽  
Vol 99 (1) ◽  
pp. 82-88 ◽  
Author(s):  
I. Etsion ◽  
D. P. Fleming
Keyword(s):  
Film Thickness ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Thickness Distribution ◽  
Maximum Load ◽  
Accurate Solution ◽  
Operating Conditions ◽  
Thrust Bearings ◽  
Practical Design ◽  
Minimum Film Thickness

A flat sector shaped pad geometry for gas lubricated thrust bearings is analyzed considering both pitch and roll angles of the pad and the true film thickness distribution. Maximum load capacity is achieved when the pad is tilted so as to create a uniform minimum film thickness along the pad trailing edge. Performance characteristics for various geometries and operating conditions of gas thrust bearings are presented in the form of design curves. A comparison is made with the rectangular slider approximation. It is found that this approximation is unsafe for practical design, since it always overestimates load capacity.

scholarly journals The Effects of Artificially-Produced Defects on the Film Thickness Distribution in Sliding EHD Point Contacts

1982 ◽  
Vol 104 (3) ◽  
pp. 365-375 ◽  
Author(s):  
C. Cusano ◽  
L. D. Wedeven
Keyword(s):  
Film Thickness ◽  
Contact Region ◽  
Thickness Distribution ◽  
Point Contact ◽  
Optical Interferometry ◽  
Point Contacts ◽  
Thickness Profile ◽  
Inlet Region

The effects of artificially-produced dents and grooves on the elastohydrodynamic (EHD) film thickness profile in a sliding point contact are investigated by means of optical interferometry. The defects, formed on the surface of a highly polished ball, are held stationary at various locations within and in the vicinity of the contact region while the disk is rotating. It is shown that the defects, having a geometry similar to what can be expected in practice, can dramatically change the film thickness which exists when no defects are present in or near the contact. This change in film thickness is mainly a function of the position of the defects in the inlet region, the geometry of the defects, the orientation of the defects in the case of grooves, and the depth of the defect relative to the central film thickness.

Influence of substrate movement on the ITO film thickness distribution during magnetron sputtering

2017 ◽  
Vol 35 (6) ◽  
pp. 061301 ◽  
Author(s):  
Ivan A. Starkov ◽  
Ilya A. Nyapshaev ◽  
Alexander S. Starkov ◽  
Sergey N. Abolmasov ◽  
Alexey S. Abramov ◽  
...  
Keyword(s):  
Magnetron Sputtering ◽  
Film Thickness ◽  
Thickness Distribution ◽  
Ito Film ◽  
Influence Of Substrate

Measurement and calculation of oil film thickness in a ball bearing

2018 ◽  
Vol 70 (8) ◽  
pp. 1500-1508 ◽  
Author(s):  
Baogang Wen ◽  
Hongjun Ren ◽  
Pengfei Dang ◽  
Xu Hao ◽  
Qingkai Han
Keyword(s):  
Film Thickness ◽  
Ball Bearing ◽  
Performance Indicator ◽  
Thickness Distribution ◽  
Content Type ◽  
Oil Film ◽  
Capacitance Method ◽  
Lubrication Condition ◽  
Series Of Experiments ◽  
External Loads

PurposeThe oil film thickness provides a key performance indicator of a ball bearing lubrication condition. This paper aims to propose an approach to calculate and measure the oil film thickness of the bearing.Design/methodology/approachOn a specially designed test rig, measurement of the capacitance is used to monitor the oil film thickness of ball bearing. A corrected film thickness formula taking account of the influences of non-Newtonian shear thinning and thermal is introduced to predict the oil film thickness of ball bearing. And then the film thickness distribution and the corresponding capacitances are calculated.FindingsMeasurement and calculation of oil film thickness in a ball bearing are carried out under various rotating speeds and external loads. By comparing the calculated capacitances with measured results, it can be concluded that the calculated results obtained by the amended film thickness formula are much closer to the test findings than the classical computed values according to Hamrock–Dowson.Originality/valueA new corrected film thickness formula is introduced in predicting oil film thickness of ball bearing and verified by the series of experiments according to capacitance method.

The influence of 3-DOF film thickness disturbance on transient performance of typical spiral groove dry gas seals

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yuan Chen ◽  
Hao Shang ◽  
Xiaolu Li ◽  
Yuntang Li ◽  
Bingqing Wang ◽  
...  
Keyword(s):  
Film Thickness ◽  
Degrees Of Freedom ◽  
Thickness Distribution ◽  
Transient Performance ◽  
Spiral Groove ◽  
Double Row ◽  
Content Type ◽  
Dry Gas Seal ◽  
Sealing Performance ◽  
Gas Seals

Purpose The purpose of this paper is to investigate the influence rule and mechanism of three degrees of freedom film thickness disturbance on the transient performance of spiral groove, upstream pumping spiral groove dry gas seal (UP-SDGS) and double-row spiral groove dry gas seal (DR-SDGS). Design/methodology/approach The transient performance of spiral groove, UP-SDGS and DR-SDGS are obtained by solving the transient Reynolds equation under different axial and angular disturbance coefficients. The transient and steady performance of the above-mentioned DGSs are compared and analyzed. Findings The film thickness disturbance has a remarkable impact on the sealing performance of DGS with different structures and the calculation deviations of the leakage rate of the UP-DGS will increase significantly if the film thickness disturbance is ignored. The axial and angular disturbance jointly affect the film thickness distribution of DGS, but there is no significant interaction between them on the transient sealing performance. Originality/value The influence mechanism of axial disturbance and angular disturbance on the transient performance of typical SDGSs behavior has been explained by theory. Considering small and large disturbance, the interaction between axial disturbance and angular disturbance on the transient performance have been studied.

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