I n the highly infomationalize~ society, information media are needed to be able to deal much bigger scale information. To cope with this demand, the magnetic tape industry seeks higher performance, smaller size and longer-play tapes materials. As the magnetic recording substrata, the new type of plastic film which has high performance properties, for example, high mechanical properties, high heat resistance and high dimensional stabilities are needed. Teijin PEN Film is the high modulus and high heat resistant film developed by Teij in Limited which is made from polyethylene-2, 6-naphthalate and is biaxially oriented so as to have uniform properties in both machine and transverse direction of film and named TEONEX@ Film. TEONEX@ Film has many superior properties in comparison with conventional polyester (PE T) film.
-. A roll coater of the Opposing Targets Sputtering and the TEONEX® (PEN) film substrate were used to prepare continuous webs for Co-Cr-Ta thin film media. And surface roughness, microstructure and magnetic properties of the continuous webs were studied in this paper. The webs obtained under the argon gas pressure in the range of 0.15 to 0.75 Pa and the roll temperature of approx. 150°C, showed the following properties which will make the development of thin film media prospective on reliability and manufacturability. Microstructures in the Co-Cr-Ta thin films of 150 nm thickness were observed to be Co-rich particles of some 20 nm in diameter being packed densely and homogeneously, segregated by 2 nm-thick Cr-rich boundary layers. Surface roughness (Rmax) and magnetic properties of the webs were almost constant and showed high quality (Rmax < 10 nm, Hc.l ~ 1000 oe, HCII::;; 260 oe and Hk -4.3 koe).
The authors have shown the possibility to introduce the Newtonian theory to the polymer flow in extruder.In this paper the behaviour of polymer in extruders was observed and dealt with some theoretical methods. The tranceparent acrylic barrel was deviced to observe the behaviour in extruder, (shown in Fig. 1, Fig. 2 in the previous report (1)).With the aim of observation of behaviour of polymer flow, small glass balls (diameter about 0.8 mm) were suspended as a fluid element, and the behaviour of the polymer was observed in the case of flat screw and the open out-let as shown in Fig. 3.
With regards to the extrusion theories about high polymer solution, the characteristics of high polymer solution in extruders has been generally treated as the non-Newtonian fluide.However, when the flow properties of polymer solution, viscosity and pressure distribution in extruder are known, it is possible to introduce the Newtonian theory to analyse the behavior of polymer flow. Then, in order to calculate the viscosities by the eq (5), the relation between the drag flow and pressure gradient in the extruder can be measured by means of closing the out-let (exit end) of extruder, and from the formula (7), the viscosity values of polymer solutions at thevarious screw rotations (various shear rates) may be calculated, whose results are as shown in Fig (9).These viscosity values and the pressure gradients measured by the experimental pressure gauge, shown in Fig (3), are introduced to the general metering screw, Fig (4 As the next step, in order to measure the structural viscosity index of high polymer, the rotary visco-meter was deviced and the structural viscosity index, (n=1.55) )was obtained.By using this structural viscosisy index (n=1.55), the extrusion out-put is calculated in the case of the general non-Newtonian theory (power law), and its results are shown in Fig (16
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