摘要:
The invention relates to systems and methods for creating a foamed part. An example method includes providing a polymer processing system, providing a mold having at least one expandable mold cavity in fluid communication with the polymer processing system, mixing polymeric material and blowing agent within the polymer processing system to produce a unfoamed mixture, injecting a volume of the mixture of polymeric material and blowing agent from the polymer processing system and into the expandable mold cavity, and expanding the mold cavity to expand the unfoamed mixture within the mold cavity and form the foamed part.
摘要:
A method of making a molded rigid polyurethane foam comprising injecting into a closed mold cavity a reaction mixture at a packing factor of 1.03 to 1.9, wherein the mold cavity is under a pressure of from 300 to 950 mbar, wherein the reaction mixture comprises an organic polyisocyanate,a polyol composition, a catalyst, optionally auxiliary substances and/or additives, and a chemical blowing agent component in an amount of from 1 to 5 weight percent based on the total weight of the components excluding polyisocyanate, the chemical blowing agent component comprising at least one chemical blowing agent, wherein the chemical blowing agent component is the sole blowing agent.
摘要:
Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung von Polyurethanschaumstoffformkörper mit einer Formteildichte von maximal 500 g/L bei dem man (a) organische Polyisocyanate mit (b) Polyesterole, (c) Treibmitteln, (d) Zellöffnende Additive, ausgewählt aus der Gruppe, bestehend aus Homo- oder Copolymeren auf Basis von Ethylhexylacrylat, Polybutadien, Polyisobuten und Diorganosilikonen oder Mischungen aus zwei oder mehreren dieser Entschäumer, (e) silikonbasierte Zellstabilisatoren und gegebenenfalls (f) Kettenverlängerungsmitteln und/oder Vernetzungsmitteln, (g) Katalysatoren und (h) sonstigen Hilfsmitteln und/oder Zusatzstoffen, zu einer Reaktionsmischung vermischt, in eine Form gibt und zu einem Polyurethanschaumstoffformkörper ausreagieren lässt. Weiter betrifft die vorliegende Erfindung Polyurethanformkörper, erhältlich nach einem solchen Verfahren und die Verwendung dieser Formkörper als Schuhsohle, Lenkrad, Sitz oder Armlehne.
摘要:
Methods for reducing the density of thermoplastic materials and the articles made therefrom having similar or improved mechanical properties to the solid or noncellular material. Also disclosed are improvements to foaming methods and the cellular structures of the foams made therefrom, and methods for altering the impact strength of solid or noncellular thermoplastic materials and the shaping of the materials into useful articles.
摘要:
Press system (10, 11, 12, 13, 14) for production of partially expanded polymer bodies, comprising a mould cavity (20) of variable volume, temperature control means (30), counter 5 pressure means (40) arranged to counteract expansion of the mould cavity during moulding, wherein the pressure applied by the counter pressure means is arranged to increase in response to expansion of the mould cavity. There is also provided a method of moulding a partially expanded polymer body.
摘要:
An earplug (12), includes a body (14), of soft elastomeric material such as a soft resilient foam for insertion in the ear canal, and a stiffener (16), of more rigid material than the body (14). The stiffener (16), is in the form of a tube rather than a solid rod, so while the stiffener is resistant to column-like collapse, it is easily radially compressed to facilitate compression of the body as it enters the ear canal. The stiffener tube can be filled with soft resilient foam material, to block the passage of sound through the tube. The tubular stiffener can have a slot extending parallel to the length of the stiffener, to allow soft foam material to flow into the tube to fill it, as the foam material that surrounds the tube is molded. Such molding can be accomplished by extruding foam material while the tubular stiffener passes with the extruded foam through the extrusion head.
摘要:
Three-dimensional foam mouldings made of a biodegradable thermoplastic polymer, in particular starch, and preferably a second biodegradable component can be manufactured in a discontinuous process by heating the polymer, in the form of an expandable bead or sheet or the like, in a mould having any desired shape under pressure in the presence of a blowing agent and subsequently depressurising. The second component can be used to enhance the water-resistance or the mould product and can be applied after, or preferably during or before the moulding step.
摘要:
Injection molding systems and methods useful for making microcellular foamed materials are provided as well as microcellular articles. Pressure drop rate and shear rate are important features in some embodiments, and the invention provides systems for controlling these parameters in an injection molding system. Another aspect involves an injection molding system including a nucleator that is upstream of a pressurized mold. Another aspect involves an extrusion system with the reciprocating screw for forming a single phase solution of non-nucleated blowing agent and polymeric material. Another aspect involves very thin walled microcellular material and very thin walled polymeric material. Another aspect provides a method for producing high weight reductions in very thin-walled parts with surfaces that have no noticeable differences from non-foamed parts.
摘要:
In an object, in particular a plate, which contains compressed granules of hard polyurethane foam and binders, the granules have a particle size not greater than 10 mm. The bulk material from which the object is manufactured contains 10 % to 90 % of polyurethane foam particles and is compressed in a first compression stage at a pressure not greater than 20 kp/cm2 and in a second compression stage at a pressure not greater than 40 kp/cm2 and a temperature less than 170°C. A plate having a thickness of approximately 8 to 11 mm manufactured by this process has a flexural strength of at least 22 N/mm2, a thickness swelling of less than 2 % and a moisture content of less than 3 %.