Abstract: A process and apparatus for the continuous solid state forming of semicrystalline polymers using roll-drawing is disclosed. The output of an extruded thick polymer profile is stabilized by a gear pump. The profile is passed through a die for the desired geometry and a cooling calibrator. The profile is heat conditioned in heating tunnels to a temperature below the melting point prior to deformation between sets of rolls. A plurality, e.g. four pairs of rolls apply both compression and tension to the polymer profile. The tension applied on the profile, the roll gap, the linear speed of the profile and its temperature are monitored and controlled for the amount of polymer deformation and relaxation allowed. High tensile modulus and strength, both in the longitudinal and transverse direction of the polymeric strip, can be achieved.

Abstract: A method and apparatus for determining surface molecular orientation and related properties of an opaque polymeric sheet relies on the detection of relative intensity of spectral reflectance in at least one polarized beam reflected from the surface of the sheet rather than transmitted therethrough. The relative intensity is affected by the preferential orientation of the polymeric chains. The method is fast and can be applied on-line at a speed of the running sheet as high as 1000 m/s.

Abstract: A process for controlling the relative viscosity of synthetic yarns during production thereof. At least three pressure measurements are taken at three spaced locations in a transfer line for carrying molten polymer to a spinneret. Temperature and throughput of polymer in said transfer line are measured. An estimated relative viscosity of yarn produced by employing a predetermined correlation between pressure drop, throughput, temperature and relative viscosity is then calculated. A meaningful operating condition in the melting zone is adjusted in response to deviations in the estimated relative viscosity of said yarn from a desired relative viscosity of said yarn.