Hoechst Aktiengesellschaft

Hostaglas, Ltd.

Wolfgang Gawrisch

Ursula Murschall

Hermann Dallmann

Hartmut Hensel

Werner Schaefer

Rainer Brunow

Walter Valentin

Thomas Trzebiatowski

Helmut Czepl

The invention relates to an amorphous, transparently colored sheet having a thickness in the range from 1 to 20 mm, which comprises, as the main constituent, at least one crystallizable the thermoplastic and a dyestuff which is soluble in the thermoplastic, to a process for its production and to its use.

Amorphous, transparently dyed plate of a crystallisable thermoplastic, process for its production and its use

The invention relates to a transparent, amorphous sheet having a thickness in the range from 1 to 20 mm which contains, as principal constituent, a crystallizable thermoplastic, where the surface gloss, measured in accordance with DIN 67530 (measurement angle 20&deg;), is greater than 130, the light transmission, measured in accordance with ASTM D 1003, is greater than 84%, and the haze of the sheet, measured in accordance with ASTM D 1003, is less than 15%, to a process for the production of the sheet, and to the use of the sheet.

Amorphous transparent plate made of crystallizable thermoplastic materials

The invention concerns a polyester film with improved abrasion resistance, dimensional stability, drawability and slip properties. The film is characterized by the fact that it contains 0.005 to 5.0% by weight of organic, preferably hardened or crosslinked, particles with narrow particle size distribution in a range between 0.01 and 5 microns, as well as a nucleating agent in an amount from 0.01 to 10% by weight, both values related to the weight of the polymers which form the film.

Polyester film

An interference image of a biaxially stretched film strip 4 is generated optically. Streaks in the film strip are areas of different orientation and/or thickness d which are distinguished from the streakfree areas in the interference image by clearly different intensities. In order to generate the interference image, a light-source 1, a diffuser screen 2 and a polarizer 3 are arranged on one side of the film strip 4, and an analyzer 5 and a filter 6 are arranged on the other side of the film strip 4. The light beam of the light source 1 is polarized by the polarized 3 and, within the film (whose main refractive indices n.sub.1 and n.sub.2 have an angle of 45.degree. or 135.degree. respectively to the polarization plane) is split into two beams, oscillating perpendicularly to one another, which have a path difference .GAMMA.=(n.sub.1 -n.sub.2)d after emerging from the film. Of the light behind the film, in general elliptically polarized, only that portion of the light which oscillates parallel to the analyzer plane, which is perpendicular to the polarization plane, passes through the analyzer 5. In general, a colored interference image is obtained if the light source emits polychromatic light. A detector 7 as light-sensitive element, e.g. a video camera, comprising a light-sensitive diode matrix, which is connected to an image analysis and computing unit 8 for evaluation of the interference image, is arranged behind the filter, which serves to increase the contrast of the image.

Method and device for determining the change in thickness and/or

Polyester film having improved abrasion resistance manufactured from

The orientation state of a film material is determined from the double refraction during the manufacturing process. A light source irradiates the film material to measure the path difference corresponding to the anisotropy of the film material. Interference patterns, created by one or more compensating wedges, are recorded by a photosensitive diode matrix. The individual electrical signals generated by the diode matrix are subjected to level discrimination by a discriminator and generated as binary images, each of which has a single interference stripe, which is evaluated. Interference patterns from different irradiation directions are simultaneously imaged next to each other and/or above one another. If an interference stripe cannot be found in a diode line, the system switches to the diode lines of the diode matrix which are above or below it. The thickness of the film material is measured and the double refraction calculated from it along with the path difference. The correlation of double refraction with different material properties such as strength, thermal conductivity, and compressibility provides information about material properties even during manufacture. All the data obtained are storable on data storage media and are used to control the system.

Process and apparatus for continuous determination of the states of

Disclosed is a method for optically generating a scatter pattern of a biaxially stretched foil web at at least two positions of the foil web in the longitudinal and/or transverse direction. The scatter pattern is, in particular, rotated by transverse stretching in relation to a principal orientation direction. This rotation causes a change of the optical anisotropy condition of the foil web. The magnitude of the rotation is measured and utilized for the regulation of the temperature of a temperature field for the thermal fixing of the foil web, the orientation condition of the molecule chains in the foil web being made uniform as a result of the regulation of the temperature field. In order to generate the scatter pattern, a light source and at least one polarizer are disposed on one side of the foil web and an analyzer is disposed on the other side of the foil web. The light beam from the light source is polarized by the polarizer and oscillates in a specific plane of oscillation. The scatter pattern is produced by scattering at the molecule chains of the foil web. Behind the analyzer is situated a light-sensitive element, for example, a photocell or a video camera, which is connected to a computer for the evaluation of the contrast values of the scatter pattern.

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Gau-Bischofsheim, Germany

Wolfgang Gawrisch