Draw ratios have been measured for samples of polyethylene and trons‐polyisoprene, crystallized at various temperatures and at various degrees of orientation. The values obtained range from unity, i. e., no drawing is observed, up to values of about 15X for materials crystallized in the oriented state and then drawn in a perpendicular direction. The results are in rough accord with a simple molecular network model in which network strands are incorporated into crystallites with a number of reversals of direction (folds), and the remainder of a strand between network junctions is randomly arranged. The reduction in draw ratio with increasing temperature of crystallization and with increasing orientation at the time of crystallization is then accounted for in terms of a reduction in the number of reversals (folds) per molecular strand. Differences in natural draw ratio for different polymers are attributed to variations in characteristic sequence length within a crystallite and in the number of folds per network strand.

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Sheets of medium density polyethylene (MDPE) were extruded through a slit die containing an internal separator. Thus, the melt stream was momentarily split before emerging from the die. A line of separation was evident in the extruded sheets. It is attributed to incomplete welding or healing. Measurements of tear energy G, revealed that the extruded sheets were anisotropic and that the weld line was extremely weak after extrusion start-up, only about V5 of the strength elsewhere. As extrusion continued, the strength of the weld line increased to reach that of the bulk material after about 10 min. This is attributed to an increasing temperature of the melt in the die region, aiding interdiffusion. A sample containing 30% by weight of short glass fibers showed less initial weld-line weakness but the weld line remained weak in this case, even after long extrusion times.

We report the electrical and optical properties of structurally simple refractive-index-matched indium tin oxide (IM-ITO) films prepared on high-refractive index hard-coated polyethylene terephthalate (KM-V2) substrates by using a pilot scale roll to roll magnetron sputtering system for implementation in touch screen panels. We found that the ITO thin films are polycrystalline with a preferred (222) orientation. We determined the appropriate conditions for the deposition of simplestructure IM-ITO films on KM-V2 substrates for touch screen panels with an invisible electrode pattern. Moreover, the outgassing of the polymer substrate is very important in the roll-to-roll sputtering fabrication of high-quality IM-ITO films with the required electrical and optical properties.

Front Cover: Structurally simple refractive‐index‐matched indium tin oxide (IM‐ITO) film is succesfully fabricated by using a pilot scale roll to roll magnetron sputtering system. This IM‐ITO film is made up of only three layers including high refractive hard coating layer, SiO2 and ITO thin film. And we could have good quality IM‐ITO films with electric resistance of ∼ 150 Ω□‐1 and high transmittance of ∼ 90% after outgassing process. Further details can be found in the article by Cheol Hwan Kim et al. http://doi.wiley.com/10.1002/ppap.201500057.