High-Density Recording Characteristics of Obliquely Oriented Particulate Magnetic Tapes by Removal of Disoriented Surface Layer
In order to achieve high recording densities, wide bandwidth and high output, a magnetic tape should have a high Bs, perpendicular orientation, a smooth surface, good head contact, and a small longitudinal component. By using a "LIPS" orienting process which produces media with a longitudinally oriented inside layer and a perpendicular oriented surface layer, we have fabricated obliquely oriented magnetic films based on acicular metal particles; of these, tape oriented at 45° had the widest-bandwidth characteristics. But a significant improvement in output was not obtained because of the existence of disoriented particles in the surface layer, resulting from calendering treatment. We tried to remove this surface layer using polishing sheets. An obliquely oriented (45°) tape exhibited an improvement in short-wavelength output (by 10 dB at 0.3 ¿m) after the thickness of the disoriented layer was reduced by 0.12 ¿m.
A Particulate Medium Oriented Longitudinally Inside and Perpendicularly at Surface
This report takes another look at the VAST (Vertical magnetic orientation-AC demagnetization-Smoothing period-sequential Train) technique used to fabricate double-layer particulate media oriented longitudinally inside and perpendicularly at the surface from CrO2 particles and nitrocellulose with a urethane binder. Infrared irradiation was performed to evaporate the solvent instead of natural evaporation to improve the viscosity of the surface perpendicular oriented layer, and to ensure a controlled thin, uniform thickness surface layer.
Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 ? 1 Rib Cotton Knitted Fabrics
This study investigates the impact of yarn count and stitch length of 100% cotton knitted fabrics. 1 × 1 ribs structured fabrics were used in this research work. The stitch length 2.50 mm, 2.52 mm, 2.60 mm, 2.70 mm, 2.80 mm and 2.96 mm were used of the yarn count of 26Ne, 28Ne and 36Ne. The areal densities of the grey fabrics were in various amounts. The impacts of yarn count and stitch length were measured concerning pilling resistance, abrasion resistance, and shrinkage and tightness factor. The result showed that the fabric pilling grade decreased while number of cycle increased. Abrasion resistance decreased but length wise shrinkage increased despite the fact that the stitch length increased. The results also exposed that the tightness factor of the fabric increased with the increase of the stitch length in both dyeing and washing state and finished state compared to grey state for the yarn count 26Ne and homogeneous result not found for yarn count 28Ne and 36 Ne. Evaluation of Impact of Yarn Count and Stitch Length on Pilling, Abrasion, Shrinkage and Tightness Factor of 1 × 1 Rib Cotton Knitted Fabrics