Abstract:
A method of making a microporous sheet is provided which comprises the steps of melt blending crystallizable thermoplastic polymer with a compound which is miscible with the thermoplastic polymer at the polymer melting temperature but immiscible on cooling below the polymer melting temperature, forming a sheet of the melt blend, cooling the sheet to a temperature at which the compound becomes immiscible with the polymer to cause phase separation to occur between the thermoplastic polymer and the compound to provide a sheet comprising a first phase comprising particles of thermoplastic polymer in a second phase of said compound, orienting the film in at least one direction to provide a network of interconnected micropores throughout the sheet. The microporous sheet comprises about 30 to 80 parts by weight crystallizable thermoplastic polymer and correspondingly about 70 to 20 pans by weight of the compound. The oriented sheet has a microporous structure characterized by a multiplicity of spaced randomly dispersed, equiaxed, non-uniform shaped, non-porous particles of the thermoplastic polymer which are coated with the compound. Adjacent thermoplastic particles within the sheet are connected to each other by a plurality of fibrils consisting of the thermoplastic polymer. The fibrils radiate in three dimensions from each particle. The compound may be removed from the sheet. e.g., by solvent extraction.
Abstract:
Für die Regelung der Querschnittsgestaltung von frei schäumenden Polymeren, hauptsächlich Polyurethanen bei der Herstellung von Schaumblöcken wird mit Hilfe der zwischen der Oberfläche des Polymers und einem darüber angeordneten Regelschirm strömenden Gase ein Druckun terschied hergestellt, dessen Wert durch Grobregelung in die Nähe eines Arbeitspunktes in einem Bereich von max. 10 mm WS, zweckmäßig 2-6 mm WS, gebracht wird. Der Wert des Druckunterschiedes wird durch die Feinregelung, die die Menge der strömenden Luft durch die Einführung von falscher Luft ändert, in einem in der Nähe dieses Arbeit spunktes stabiliserten Zustand innerhalb einer Grenze von ± 0,1 mm WS gehalten. Für das Gerät zur Durchführung des obigen Verfahrens ist kennzeichnend, daß ein Regelschirm (1) eine verschiebba re oder kippbare Kiemenplatte (10) besitzt, deren Steueror gan mit dem auf den Regelschirm montierten Druckfühler des Feinregelkreises elektrisch verbunden ist, während das Steuerorgan des verschiebbar oder kippbar aufgehängten Regelschirmes elektrisch an den mit der Kiemenplatte ver bundenen Lagefühler des Grobregelungskreises angeschlos sen ist. Die erfindungsgemäße Lösung ermöglicht neben einer betriebssicheren Funktion eine Regelung mit außerordent lich hoher Genauigkeit und dadurch eine ideale Quer schnittsgestaltung, was den Materialverlust auf ein Mini mum senkt.
Abstract:
There is disclosed a system for controlling an extrusion line for foamed insulation cables. In this system, a foaming insulation compound composed of a polyolefin resin and a foaming agent is supplied to an extruder (17), and extruded and coated as a foamed insulation onto a continuously fed cable conductor (13) at a temperature higher than a decomposition temperature of the foaming agent to produce a cable that is subsequently passed through a cooler unit (27) for controlling the outside diameter and electrostatic capacity of the foamed insulation. The system is controlled so that a plurality of measured variables including a plurality of controlled variables such as the outside diameter and the electrostatic capacity and condition variables affecting the controlled variables, such as a cylinder temperature of the extruder, a crosshead temperature of the extruder, a resin temperature and a resin pressure in the crosshead, are variable in predetermined correlation with a plurality of manipulated variables as input parameters which vary the controlled variables, such as a line speed of the extrusion line, a voltage applied to a preheater disposed in front of the extruder, an RPM of a screw in the extruder, a voltage applied to a cylinder heater in the extruder, a voltage applied to a crosshead heater, and a distance which the cooler unit is movable. The controlled variables are controlled so as to be adjusted into target values therefor by manipulation variables which are produced by effecting an integrating action on variable factors which are derived from the differences between the target values and the controlled variables.
Abstract:
A process and system for the formation of a polymer foam sheet of comparatively uniform biaxially orientation and comparatively uniform dimensions prepared by extruding polymer foam so that it rides on a fluid bearing film between the point of extrusion and a point of diameter expansion of the extruding tube.
Abstract:
Es wird ein flexibler, geschlossenzellig geschäumter Dämmstoff, bestehend aus einem thermoplastischen vemetzten Polyolefin vorgeschlagen, der ohne Beeinträchtigung seiner Wirksamkeit bei Temperaturen oberhalb 130°C bis zu etwa 160°C verwendet werden kann. Der Dämmstoff ist mindestens teilweise aus einem Pfropfpolymer bestehend aus einem Polyolefin oder Polyolefin-Copolymer und einem Vinylsilan sowie einem Katalysator für Feuchtigkeitsvemetzung geschäumt und feuchtigke i tsvemetzt. Eine hohe Wärmebes- tändigke i t wird auch erreicht, wenn der Dämmstoff das Pfropfpolymer nur in einem bestimmten Anteilsbereich enthält, wobei der Rest aus einem peroxidisch vemetzten Polyolefin oder Polyolefin-Copolymer besteht.
Abstract:
The invention relates to reaction injection molded elastomers containing a minor amount of polyurea linkages derived from high molecular weight amine terminated polyethers, a hydroxyl terminated chain extender and a polyisocyanate. The reaction injection molded (RIM) elastomers of this invention are useful, for example, as automobile body parts.
Abstract:
The present invention is directed to an improved apparatus and method for manufacturing completed foam plastic containers. An endless mandrel chain carries cup forming mandrels along a manufacturing path. After each mandrel is preheated, a bottom blank is placed on the mandrel bottom and held there by a vacuum. A cylindrical blank formed from longitudinally stretch-oriented foam sheet material is then placed onto the mandrel. This cylindrical blank is tightly tamped onto the mandrel and is clamped in place. Radiant heat is then used to shrink form a finished container. The bottom is then sealed to the cylindrical blank and the mandrel is transferred to a curling assembly where the top edge portion of each finished container is lubricated and then curled to form a finished rim. The apparatus of the present invention may form containers having a dual tapered configuration which allows the containers to be more tightly stacked.
Abstract:
Schaumstoffbahn aus einem geschlossenzellig geschä umten, vernetzten Polyolefinkörper, der eine Ober- und eine Unterseite auweist und wobei die Ober- und/oder die Unterseite durch in den Schaumstoffkörper eindringende, musterartig über die Fläche verteilte Kanäle unterbrochen ist, in denen fest Teilchen (7) eingelagert sind.
Abstract:
A process for producing a shaped article of a non-cellular or microcellular polyurethane elastomer by reaction injection molding by using at least two components of (A) a polyol component comprising a high molecular weight polyol and a chain extender as essential ingredients and (B) an isocyanate component comprising a polyisocyanate compound as essential ingredient, characterized in that substantially all or at least 80% by weight of said high molecular weght polyol is composed of a polyoxyalkylene polyol, and the polyoxyalkylene polyol is a single or mixed polyoxyalkylene polyol which has an average hydroxyl number of from 2.0 to 3.5 and an average hydroxyl value of from 15 to 60 and contains at least 5% by weight, in an average, of oxyethylene groups at the terminal portions of the oxyalkylene chain and in which the total oxyethylene group content is, in an average, less than 21 % by weight and the average unsaturated monool content is at most 0.085 meq/g.