Abstract:
A method of treating fibers to improve resistance to high temperatures and relative humidity includes providing poly(p-phenylene~2,6-benzobisoxazole) (PBO) fibers, exposing the PBO fibers to an atmosphere of supercritical CO2 saturated with an epoxy silane, i.e. 3-glycidoxypropyl methyldimethoxysilane. The PBO fibers are subjected to a first pressurizing and heating stage at a first temperature (50°C) for a first period of time. The PBO fibers are then subjected to a second pressurizing and heating stage including increasing the temperature to a second temperature (110°C) and holding at the second temperature for an additional period of time. The PBO fibers include 2-5 wt% of 3-glycidoxypropyl methyldimethoxysilane after diffusing the CO2 out of the PBO fibers. The fibers are particularly useful in making lightweight body armor system components.
Abstract:
A method of treating fibers to improve resistance to high temperatures and relative humidity includes providing poly(p-phenylene~2,6-benzobisoxazole) (PBO) fibers, exposing the PBO fibers to an atmosphere of supercritical CO2 saturated with an epoxy silane, i.e. 3-glycidoxypropyl methyldimethoxysilane. The PBO fibers are subjected to a first pressurizing and heating stage at a first temperature (50°C) for a first period of time. The PBO fibers are then subjected to a second pressurizing and heating stage including increasing the temperature to a second temperature (110°C) and holding at the second temperature for an additional period of time. The PBO fibers include 2-5 wt% of 3-glycidoxypropyl methyldimethoxysilane after diffusing the CO2 out of the PBO fibers. The fibers are particularly useful in making lightweight body armor system components.
Abstract:
In exemplary implementations of this invention, a network of nodes controls and senses the cure of a thermosetting plastic in a component that is made of fiber composite material. The network comprises multiple nodes, which are separated spatially from each other. Each of the nodes, respectively, comprises a heat transfer device for actively transferring thermal energy, a temperature sensor for taking local temperature measurements, and a processor. In each of the nodes, respectively: (a) the processor locally performs closed loop control over the temperature of the heat transfer device, and (b) the closed loop control is based at least in part on the local temperature measurements and on estimated or measured input current to the heat transfer device.
Abstract:
Uma etapa de vulcanização de pneus em autoclave com sistema de aquecimento for indução aplicada em processo de vulcanização/recauchutagem de pneus representa uma solução inventiva baseada no principío que materiais condutivos, metal e borracha, podem ser aquecidos através da tecnologia de indução de calor nas lonas de aço, ou na borracha dependendo das características construtivas e estruturais do tipo de pneu a ser vulcanizado e ainda dependendo do nível de condutividade e materiais empregados em sua fabricação, onde dentro deste novo processo tem-se que para uma peça na forma de pneu, o aquecimento indutivo é limitado às camadas superficiais deste e seu núcleo deve permanecer inalterado, onde esta condição apresenta vantagens na conservação de energia e na distorção reduzida à que fica exposta a peça "pneu", onde a penetração de calor nas áreas a serem vulcanizadas será efetuada por condução exigindo assim apenas tempo necessário para o calor atingir tal área. Em derradeiro uma vez carregado o equipamento autoclave com pneus preparados (Pp) a vulcanização do pneu pode ser obtida por indução externa (Ie), indução interna (Ii) e indução central (Ic), onde a escolha do tipo de indução aplicada é definida por parâmetros previamente conhecidos para o pneu preparado (Pp), tal como condutividade dos materiais aplicados e montados para auxiliar o processo de vulcanização; condutividade dos componentes estruturais do pneu; sistemas de indução adequados e posicionamento dos dispositivos de indução.
Abstract:
A method for curing a rubber article including maintaining a measured curing temperature between a high temperature limit (TH) and a low temperature limit (TL). The TH TL are derived from high and low temperature curing curves respectively. Other steps may include obtaining a curing target Al or A2, wherein Al and A2 are areas between the high temperature curing curve and a base temperature (TB) and the low temperature curing curve respectively wherein TB is selected to make Al and A2 within at least 10 % of each other and determining an area under a measured curing curve, the area under the measured curing curve being between the measured curing curve and the TB, wherein the measured curing curve is defined as a plot of the measured curing temperature over time.
Abstract:
Techniques and apparatus for providing a flexible shape low volume (102) autoclave are disclosed. In one embodiment, an autoclave includes an elongated pressure vessel that is sealed on both ends and has a circumferential joint (110) between a first portion (104) and a second portion (106). The autoclave further includes the portions defining an interior configured for accepting an elongated part, the joint (110) being configured to create an angle between the portions and further creating an opening with a seal, the opening facilitating an insertion of the part into the interior, and the seal enabling pressurization of the interior.
Abstract:
The present invention relates to a method for producing profile parts (31, 32), each having an L-shaped cross-section (33, 34), or an assembled profile part (43) having, in particular, a T-shaped cross-section. For this purpose a lay-up (1) made of composite fibre material is initially placed on a forming tool (3). In a further step, the lay-up is deformed by the forming tool (3) to form a profile (16) having a preferably U-shaped cross-section (21), the profile (16) thus exhibiting the book effect at each opposite end (24, 25). In a further step, the profile (16) is preferably cut in the longitudinal direction (26) in order to produce two profile parts (31, 32). The idea on which the invention is based is to allow the layers (2a, 2b, 2c) in the lay-up (1) to shift during the deformation process and subsequently to produce a substantially right-angled chamfered end (24 or 25) on the profile parts (31 or 32) by means of a cutting process. The disadvantageous formation of corrugations and complex clamping of the lay-up (1) are thus avoided.
Abstract:
A method and article of manufacture of joining a stringer to a wing or tail panel and curing a wing or tail panel is disclosed. A sheet of titanium is placed between a cured stringer and an uncured wing or tail panel. The stringer, wing or tail panel and sheet are then placed within a vacuum bag, and gas is pumped out of the bag. The bag is then placed in an auto-clave to cure the wing or tail panel.
Abstract:
An autoclave is provided for heat treatment of a load whose position relative to the autoclave , whose cross-section and/or whose thermal characteristics may vary along the load, e.g. large panels for an airliner. The autoclave comprises a chamber for receiving the load, a wall of said chamber providing one end thereof and a door providing the other end of the chamber and giving access for insertion and removal of the load. Means (110, 112) is provided for heating gas in the chamber, and a plurality of gas circulation means (114-130) are provided spaced along the length of the autoclave and each producing a zone for circulation of heating gas. Means (74-92; 114-130; 144-148; 150-154) is provided for independent control of the rate of heat transfer between the heating gas and the load in said zones and said gas circulation means is arranged to produce a pattern of circulation in which heating gas impinges non-axially onto the load.
Abstract:
A method of manufacturing light guide by filling a polymer tube with a monomeric mixture then pressurising and heating the full length of the polymer tube to initiate and maintain polymerisation in the tube. An apparatus for performing the method is also described in which the polymer tube is placed in a reaction vessel and a temperature controlled fluid is circulated to regulate the temperature in the vessel.