Abstract:
A method of manufacturing a fibre reinforced thermoplastic product, the method comprising: (a) heating a thermoplastic and fibre composition to a first temperature T 1 under a first pressure p 1 for a first period of time t 1 ; (b) reducing the pressure applied from p 1 to a second pressure p 2 and heating the composition to a second temperature T2 under p 2 for a second period of time t 2 ; and (c) increasing the pressure from p 2 to a third pressure p 3 and applying p 3 for a third period of time t 3 ; wherein: the temperatures T 1 and T 2 are equal to or greater than the melt temperature T m of the thermoplastic; the temperature cools from T 2 to a temperature below the melt temperature T m of the thermoplastic in t 3 .
Abstract:
Methods for curing tires, and corresponding systems and tires formed thereby include providing a system for curing retreaded tires, the system including a series of chambers. Such methods also include providing an unbonded retreaded tire, placing the unbonded retreaded tire into an input chamber, sealing the input chamber, conveying the unbonded retreaded tire from the input chamber, sealing a curing chamber among the series of chambers, pressurizing the curing chamber to a target curing pressure, heating the curing chamber to a target curing temperature, curing the unbonded retreaded tire in the curing chamber to form a cured tire, unsealing the curing chamber to a removal chamber among the series of chambers, conveying the cured tire from the curing chamber to the removal chamber, depressurizing the removal chamber, unsealing the removal chamber; and removing the cured tire therefrom.
Abstract:
The present invention relates to an arrangement for treatment of articles by hot pressing and, in particular, by hot isostatic pressing. In particular, the present invention relates to a pressing arrangement for treatment of articles by hot pressing, and preferably hot isostatic pressing, capable of providing a controlled, rapid cooling rate. The pressing arrangement comprises a pressure vessel including a furnace chamber comprising a heat insulated casing and a furnace adapted to hold the articles. At least one cooling circuit is arranged on an outside of the pressure vessel, the cooling circuit comprising a coolant and being arranged to enable the coolant to flow along a central portion of an outer wall of the pressure vessel. The pressure vessel is arranged with a non-uniform wall thickness, where the vessel wall is thickest at upper and lower end portions of the pressure vessel.
Abstract:
Procedimiento para fabricar una pieza de un material compuesto hecho con una resina polimérica y un refuerzo fibroso a partir de, al menos, dos subcomponentes, que comprende las siguientes etapas: a) Proporcionar el primer subcomponente curado parcialmente en un ciclo de curado en autoclave a una temperatura máxima T1, comprendida entre la temperatura TG de gelificación de la resina y la temperatura TC de curado de la resina, aplicada durante un tiempo predeterminado TP1 de manera que se libere la componente exotérmica del primer subcomponente en un grado superior al 50%; b) Proporcionar el segundo subcomponente, en estado fresco o curado; c) Ensamblar los dos subcomponentes y proceder a su unión en un ciclo de curado en autoclave a una temperatura máxima T2 comprendida entre el 90% y el 100% de la temperatura TC de curado de la resina, aplicada durante un tiempo predeterminado TP2.
Abstract:
"PROCESS FOR MANUFACTURE OF SANITARY WARE ACRYLIC PLATES, OF SYNTHETIC GRANITE, USING CAST SYSTEM, WITH OR WITHOUT ABS REINFORCEMENT", presenting an inedited process for obtaining sanitary ware - synthetic granite type acrylic, providing for the execution of two polymerization stages, the stage called first polymerization (D), is defined by a step called first mould preparation (D1); a step called mould filling (D2), where the mould is filled with the first formulation; a step called polymerization (D3) where the moulds are placed inside an autoclave, this operation obeying a thermal curve where the initial temperature is 50°C, and after one hour this temperature is increased to 120°C and maintained constant until the end of the period with a total time of five hours, and after four hours begins the cooling step (D4) of the moulds and the plates polymerized inside it, passing to a mould cooling step (D4), plate demoulding step (D5); plate grinding step (D6) where the plates are grinded; a step called particle selection (D7). The stage called second polymerization (E) presents a first step called second mould preparation (El); a step called mould filling (E2); a step called degassing (E3); a step called polymerization (E4), where they are filled with the second formulation and placed inside the autoclave, whose thermal curve presents initial temperature of 50°C, increased to 80°C and maintained for one hour, after this period the temperature is increased to a level of 120°C and maintained until the end of the period of four hours, after which begins the step of second cooling of the moulds (E5), where the moulds return to the autoclave, with a new and final polymerization; a step of final demoulding of the plates (E6).
Abstract:
The invention relates to a process for the production of a polymer layer of a flexible unbonded offshore pipe. The process comprises the steps of shaping a polymer material by extrusion into or onto a supporting unit in an extrusion station and cross-linking said extruded polymer material, said polymer material comprising a polyethylene and a peroxide for providing a cross-linking of the polymer material. The peroxide has an activation temperature substantially above the temperature of the polymer material during the extrusion thereof. The crosslinking of the extruded polymer material is carried out by exposing the extruded polymer material to electromagnetic waves, selected from the group consisting of infrared radiation and microwave. The invention also relates to a flexible unbonded offshore pipe comprising such polymer layer.
Abstract:
A method for forming a vehicle headliner (112) comprises providing at least one layer of formable material (114) and a cover member (116); heating the layer (114) and the cover member (116); providing a mold (110, 210) having a pair of mold halves (120, 122) and a compressible seal (130) disposed between the mold halves (120, 122), at least one of the mold halves (122) having an aperture (133) and a channel (134) in communication with the aperture (133); positioning the layer (114) and the cover (116) member between the mold halves (120, 122); bringing the mold halves (120, 122) toward each other to effect a sealed relationship; and applying a vacuum pressure to the aperture (133) to sufficiently draw the mold halves (120, 122) together and compress the seal (130), thereby compressing the at least one layer (114) and the cover member (116) together to form the headliner (112). An apparatus for practicing the method is also disclosed.
Abstract:
An apparatus is presented for the rapid curing of resinous materials by application of energy from an external source to excite polymerization in a polymerizable system under controlled temperature and pressure. The apparatus comprises a chamber and at least one inert gas flash lamp light source arranged at a predetermined distance from the chamber to irradiate an object positioned on the sample holder. Preferably, the inert gas light source is at least one inert gas linear flash lamp positioned to effectively irradiate an object positioned in the chamber. In accordance with the present invention, the inert gas flash lamp emits pulse radiation of very high energy and power peaks. Preferably, the spectral output of the inert gas flash lamp is in the range between about 350 nm and about 550 nm. The radiant energy emitted by the present apparatus is diffused or flooded to produce an even distribution of light intensity over the entire base of a chamber. The apparatus of the present invention achieves very fast cure rates, high degrees of cure, greater depths of penetration, low heat buildup and instant on-off capability and is particularly suitable for the curing of dental materials comprising filled or unfilled resin(s) having at least one ethylenically unsaturated group, in particular acrylate, methacrylate or vinyl groups.
Abstract:
A process and device are disclosed for sealing several components, such as line output transformers, in an impregnating compound which does not set at room temperature but which sets in a short time, for example in less than 30 minutes, at a higher temperature (for example 60° to 80 °C). The process includes the steps of introducing a component-carrying pallet into an evacuable casting chamber (10), evacuating the casting chamber, sealing the components in the compound in a vacuum (48), venting the casting chamber (48), removing the components, preferably conveyed on a pallet (46), from the casting chamber and introducing them into a multiple-chamber oven (60), within which the components are exposed at over-pressure to a higher temperature at which the impregnating compound sets. In order to save heating and pressure energy, the oven has a preliminary air lock, a main chamber and a discharge air lock. The main chamber is constantly under pressure whereas the air locks may be alternately put under pressure and vented.