Abstract: A rear-projection screen that has at least one light-scattering polymethyl methacrylate layer in which is embedded spherical plastic particles; the previously described rear-project screen that has an additional plastic sheet that does not have embedded scattering beads; and a method of making a rear-projection screen.

Abstract: The invention relates to a process for the production of a plastics article with a microstructured surface via production of a composite composed of a backing layer composed of a thermoplastic or thermoelastic with one or more structure layers, characterized in that the structure layer(s) is/are composed of from 1 to 100% by weight of a polymethacrylate moulding composition which comprises from 80 to 100% by weight of free-radical-polymerized methyl methacrylate units and from 0 to 20% by weight of other comonomers capable of free-radical polymerization, and which has an average (weight-average) molar mass Mw of from 30 000 g/mol to 70 000 g/mol and, where appropriate, is present in a.

Abstract: The invention relates to a solid body of plastic, glass, ceramic or metal which has at least partially a microstructured surface with rows oriented in a preferential direction of cross-sectionally trapezoidal or wedge-shaped ridges, wherein the ridges have minima and maxima in height (H) which lie in the range from 0 mm to 2 mm, and the minima and maxima follow one another periodically with amplitudes in the range from 0.005 to 20 mm, and the spacing of the rows of neighboring ridges in relation to one another is 0.002 mm to 5 mm, it being possible for the valleys between the rows to be planar, curved or tapered, and the cross-sectionally trapezoidal or wedge-shaped ridges have a wedge angle (?) in the range from 15 to 75°.

Abstract: Abstract of the Disclosure The present invention relates to rear-projection screens encompassing at least one light-scattering polymethyl methacrylate layer of thickness in the range from 0.05 to 4 mm comprising spherical particles whose size is in the range from 5 to 35 µm, at a concentration in the range from 2 to 60% by weight, based on the total weight of the light-scattering polymethyl methacrylate layer, the refractive index of the spherical plastics particles differing from that of the polymethyl methacrylate matrix by a value in the range from 0.02 to 0.2, wherein the concentration of the spherical plastics particles cP, the thickness of the light-scattering polymethyl methacrylate layer dS, and the size of the spherical plastics particles DP is selected in such a way that the ratio cP*dS/DP3 is in the range from 0.0015 to 0.015% by weight*mm/µm3 and the ratio of average surface roughness of the polymethyl methacrylate layer Ra to the size of the spherical plastics particles Dp is in the range from 0.

Abstract: The invention relates to a method for the production of films in the thickness range of 20 ?m 1,000 ?m from thermoplastic plastics by extrusion of the plastic through a broad slot nozzle (4) and polishing of the melt film (5), escaping from the broad slot nozzle in a polishing unit, comprising at least three or four rollers (1, 2, 3), whereby a first roller pair (1, 2) forms a polishing gap for holding the melt film and the melt film is then run behind said polishing unit gap through a subsequent polishing gap or a subsequent pressing gap. The above is characterised in that the ratio of the width of the nozzle gap and the film thickness lies on the range 1:1 to 6:1 and the quotient of the film web speed in the subsequent polishing gap or the subsequent pressing gap divided by the film web speed in the polishing gap formed by the roller pair (1, 2) lies in the range 0.8 to 1.05.

Abstract: The invention relates to an extrusion nozzle for shaping extruded melts produced from thermoplastics to webs of film or slabs. Said nozzle substantially comprises a nozzle body (1), at least one opening for feeding the melt (2) to a distributing channel (3) with at least one retaining island (4) and a slit die-type nozzle emergence zone (5). The melt (2) is fed to the distributing channel (3) laterally relative the extrusion direction (E) predetermined by the nozzle emergence zone (5). The invention further relates to a corresponding production method and to films and slabs produced according to the inventive method.

Abstract: The present invention relates to rear-projection screens encompassing at least one light-scattering polymethyl methacrylate layer of thickness in the range from 0.05 to 4 mm comprising spherical particles whose size is in the range from 5 to 35 &mgr;m, at a concentration in the range from 2 to 60% by weight, based on the total weight of the light-scattering polymethyl methacrylate layer, the refractive index of the spherical plastics particles differing from that of the polymethyl methacrylate matrix by a value in the range from 0.02 to 0.2, wherein the concentration of the spherical plastics particles cp, the thickness of the light-scattering polymethyl methacrylate layer ds, and the size of the spherical plastics particles Dp is selected in such a way that the ratio cp*ds/Dp3 is in the range from 0.0015 to 0.015% by weight*mm/&mgr;m3 and the ratio of average surface roughness of the polymethyl methacrylate layer Ra to the size of the spherical plastics particles Dp is in the range from 0.05 to 0.4.

Abstract: A plastic body including a base molded body produced from a transparent, thermoplastic base material, and that includes at least two opposing flat layers interconnected by vertical or diagonal connecting elements. One of the flat layers is provided with an additional layer of a plastic matrix in a transparent, plastic base material. The additional layer is an IR-absorbent layer containing at least one IR-absorber that does not impair transparency of the plastic body and has an average transmission of less than 80% in the region of the near-infrared radiation (780 nm to 1100 nm). The plastic body has a light transmission of between 15% and 86%, a maximum heat transition coefficient of 4 W/m2K and a minimum Sk value of 1.15. The plastic body can be used, e.g., as a glazing element, a roofing element, a heat insulating element.

Abstract: The invention relates to a solid body of plastic, glass, ceramic or metal which has at least partially a microstructured surface with rows oriented in a preferential direction of cross-sectionally trapezoidal or wedge-shaped denticles, characterized in that the denticles have minima and maxima in height (H) which lie in the range from 0 mm to 2 mm, and the minima and maxima follow one another periodically with amplitudes in the range from 0.005 to 20 mm, and the spacing of the rows of neighboring denticles in relation to one another is 0.002 mm to 5 mm, it being possible for the valleys between the rows to be planar, curved or tapered, and the cross-sectionally trapezoidal or wedge-shaped denticles have a wedge angle (&agr;) in the range from 15 to 75°.

Abstract: Multilayer plastic composites containing at least two incompatible plastics, A and B, in which the layering sequence alternates between A and B, the layers of plastic B are discontinued at regular intervals, and the resulting gaps in the layers are filled in with plastic A, exhibit good adhesion between the layers. In preferred embodiments of the invention, the amorphous, crystalline, or semi-crystalline plastic B has a higher coefficient of thermal expansion than the amorphous plastic A. The plastic composite is preferably produced via coextrusion.

Abstract: The invention relates to optical diffuser plates (1) made of transparent plastics such as polycarbonate or polymethacrylate. Several thin strips (2) made of plastic B inserted into plates made of transparent plastic A with the proviso that A and B are incompatible and the strips (2) made of plastic B are subsequently withdrawn. The hollows that are formed in the plate (1) made of plastic A are used to deflect light.

Abstract: Multilayer plastic composites containing at least two incompatible plastics, A and B, in which the layering sequence alternates between A and B, the layers of plastic B are discontinued at regular intervals, and the resulting gaps in the layers are filled in with plastic A, exhibit good adhesion between the layers. In preferred embodiments of the invention, the amorphous, crystalline, or semi-crystalline plastic B has a higher coefficient of thermal expansion than the amorphous plastic A. The plastic composite is preferably produced via coextrusion.

Abstract: Multilayer plastic composites containing at least two incompatible plastics, A and B, in which the layering sequence alternates between A and B, the layers of plastic B are discontinued at regular intervals, and the resulting gaps in the layers are filled in with plastic A, exhibit good adhesion between the layers. In preferred embodiments of the invention, the amorphous, crystalline, or semi-crystalline plastic B has a higher coefficient of thermal expansion than the amorphous plastic A. The plastic composite is preferably produced via coextrusion.

Abstract: A process for the extrusion of plastic plates with very finely structured surface using an extrusion system which is equipped with an extruder and a three roll polishing stack containing a roller with the structuring surface. The system is designed for coextrusion and the plastic plates are produced via two extruders as a coextrudate CX from a highly viscous basic molding compound BF and a low viscosity molding compound NF which is extruded on BF. The surface of said plates is structured via the three roll polishing stack. Fresnel lenses produced by the process may be used in solar collectors.

Abstract: A process for the extrusion of plastic plates with very finely structured surface using an extrusion system which is equipped with an extruder and a three roll polishing stack containing a roller with the structuring surface. The system is designed for coextrusion and the plastic plates are produced via two extruders as a coextrudate CX from a highly viscous basic molding compound BF and a low viscosity molding compound NF which is extruded on BF. The surface of said plates is structured via the three roll polishing stack. Fresnel lenses produced by the process may be used in solar collectors.

Abstract: The invention relates to transparent composite plate systems of a) at least two acrylic glass exterior plates S, S' with a thickness of at least 2 mm and parallel surfaces, and b) an intermediate layer Z containing a thermoplastically processable elastomer E, whereby the elastomer E contains from 60-100% by weight of a comb polymer KP, which itself contains from 50 to 5% by weight of at least one polymethyl methacrylate macromonomer of Formula I ##STR1## and from 95 to 50% by weight of alkyl acrylates of Formula II ##STR2## wherein R and R.sub.4 are defined in the claims.

Abstract: A flat web of sizable thickness made of thermoplastic can be extruded from an extrusion die without a restrictor bar if a thickness D of a restricting passage is made smaller than a shaping distance A of die lips (4, 5), and if at least one wall of the restricting passage (6) is adjustably designed as an elastic lip (7) by adjusting elements (8), so that thickness D and distance A can be changed at the same time by actuating the adjusting elements.

Abstract: Thermoplastically re-formable plastic sheets with flameproofing means, characterized by a core layer 1-10 mm thick comprised of polyether sulfone or a similar thermoplastic, which core material has a content of at least 0.5 wt. %, preferably at least 2 wt. %, of a flame-protective additive, such as boron trioxide; and said sheet or plate further characterized by outer layers, firmly adhering to and covering the two faces of the core layer, at least 0.05 mm thick and comprised of a thermoplastic having a lower proportional content of the flame-protective additives than the core layer; are particularly useful for interior structures in passenger conveyances, such as airplanes.

Abstract: For producing a multi-extrudate of thermoplastically processable plastic, a coextrusion adapter block has a multi-part slide having a plurality of side-by-side slide sections mutually spaced in a direction transverse to the flow direction and slidably fitted in the adapter block for movement to adjustably protrude into a secondary runner for adjusting the thickness of a molten extrudate therein. A multi-layer extrudate emerging from the adapter block is further extruded in an extrusion die, and the thickness of at least one layer thereof is measured at a plurality of positions along the width thereof. The width measurements are used to control the positions of corresponding slide sections so that the layer thicknesses can be accurately controlled during an extruding operation.

Abstract: An extrusion die slot for extruding flat thermoplastic webs has a plurality of plates mounted to the flexible lip of the die body. A regulating force from a control element is applied to the plates, and so to the flexible lip, via the flexible strip pressed between the control element and the plates.