Abstract:
An extrusion die (10) includes a die body (30) having an upstream face (32) and a downstream face (34) with an extrusion profile (22) passing through the body (30) from the upstream face (32) to the downstream face (34). The walls of the extrusion profile (22) being the bearing (46) of the die (10). A pocket (40) having tapered sidewalls (70) is formed in the upstream face (32) of the die (10) and surrounds the extrusion profile (22). The configuration of the pocket (40) improves the material flow through the die (10). The configuration of the pocket (40) depends on the configuration of the extrusion profile (22). The width of the pocket (40) is small at the fast areas of the extrusion profile (22) while being large at the slow areas of the extrusion profile (22). The pocket (40) alters the entry angle of material as it enters the die (10) thus reducing friction in the die (10) and allowing increased extrusion speeds. In conjunction with the pocket (40), the die (10) has a continuous bearing (46) having a length depending on the configuration of the extrusion profile (22).
Abstract:
An extrusion die (10) includes a die body (30) having an upstream face (32) and a downstream face (34) with an extrusion profile (22) passing through the body (30) from the upstream face (32) to the downstream face (34). The walls of the extrusion profile (22) being the bearing (46) of the die (10). A pocket (40) having tapered sidewalls (70) is formed in the upstream face (32) of the die (10) and surrounds the extrusion profile (22). The configuration of the pocket (40) improves the material flow through the die (10). The configuration of the pocket (40) depends on the configuration of the extrusion profile (22). The width of the pocket (40) is small at the fast areas of the extrusion profile (22) while being large at the slow areas of the extrusion profile (22). The pocket (40) alters the entry angle of material as it enters the die (10) thus reducing friction in the die (10) and allowing increased extrusion speeds. In conjunction with the pocket (40), the die (10) has a continuous bearing (46) having the length depending on the configuration of the extrusion profile (22).
Abstract:
A method for designing an extrusion process and extrusion die includes the steps of first determining the optimal extrusion process parameters and then designing an extrusion die based on those optimal parameters. The optimal extrusion process parameters are determined by identifying the geometric characteristics of the selected extrusion profile, determining the physical characteristics of the material to be extruded, determining the physical characteristics for the extrusion processor, and detrmining the extrusion process limitation chart for the selected extrusion profile, selected extrusion material, and the selected extrusion processor. After the extrusion process limitation chart has been determined, a preferred extrusion process window is determined for the extrusion process limitation chart. A series of simulations are then run to determine if the selected temperatures and speeds result in an entire extrusion process falling within the extrusion process window. If the selected criteria result in a process that extends beyond the window, new selections are made and the simulation is repeated until the process falls entirely within the extrusion process window. The criteria are then used in a feed forward set up to run the extrusion process.
Abstract:
A method for designing an extrusion process and extrusion die includes the steps of first determining the optimal extrusion process parameters and then designing an extrusion die based on those optimal parameters.The optimal extrusion process parameters are determined by determining the geometric characteristics of the selected extrusion profile, determining the physical characteristics of the material to be extruded, determining the physical characteristics for the extrusion processor, and determining the extrusion process limitation chart for the selected extrusion profile, selected extrusion material, and the selected extrusion processor. After the extrusion process limitation chart has been determined, a preferred extrusion process window is determined for the extrusion process limitation chart. A series of simulations are then run to determine if selected temperatures and speeds result in an entire extrusion process falling within the extrusion process window. If the selected criteria result in a process that extends beyond the window, new selections are made and the simulation is repeated until the process falls entirely within the extrusion process window. The criteria are then used in a feed forward set up to run the extrusion process.
Abstract:
An extrusion die (10) includes a die body (30) having an upstream face (32) and a downstream face (34) with an extrusion profile (22) passing through the body (30) from the upstream face (32) to the downstream face (34). The walls of the extrusion profile (22) being the bearing (46) of the die (10). A pocket (40) having tapered sidewalls (70) is formed in the upstream face (32) of the die (10) and surrounds the extrusion profile (22). The configuration of the pocket (40) improves the material flow through the die (10). The configuration of the pocket (40) depends on the configuration of the extrusion profile (22). The width of the pocket (40) is small at the fast areas of the extrusion profile (22) while being large at the slow areas of the extrusion profile (22). The pocket (40) alters the entry angle of material as it enters the die (10) thus reducing friction in the die (10) and allowing increased extrusion speeds. In conjunction with the pocket (40), the die (10) has a continuous bearing (46) having a length depending on the configuration of the extrusion profile (22).
Abstract:
A Q-switched laser system is disclosed. The laser system employs a quasi-phase-matched electro-optic (QPM EO) crystal as the laser Q-switch. When applied with a certain modulating electric field, the QPM EO crystal can function as a polarization rotator to rotate the polarization direction of the resonant laser beam in a polarization-dependent laser resonator, thereby switching the laser resonator between high-loss and low-loss cavity states to achieve laser Q-switching. Compared with traditional electro-optic Q-switched laser system, the disclosed laser system is characterized by a low switching-voltage, reduced cost, and compactness. A quasi-phase-matched electro-optically Q-switched wavelength-conversion and wavelength-tunable laser system is also disclosed. The disclosed laser system integrates a QPM electro-optic Q-switch and a QPM nonlinear wavelength converter in a single crystal substrate to perform a high-efficiency intracavity wavelength conversion. The disclosed laser system is therefore simple and compact and has lower system requirements on wall-plug power and higher overall conversion efficiency.
Abstract:
A flashlight includes a main member having top, a bottom, a front and a rear. The main member has a base a head and battery pack, wherein the head is pivoted on the base via a pivot to be flexed to the front. A first light source and a second light source are mounted on the head, wherein the second light source projects light that is substantially to that of the first light source. A hook is provided in a tunnel in the base to be drawn out or pushed into. The first and second light sources and the flexion of the head provide a greater illumination range and a function of adjusting the illuminating direction when it is hung.
Abstract:
A laser-wavelength conversion system with a broad temperature acceptance bandwidth is provided. The laser system includes a broad-band pump laser driving one or several cascaded laser wavelength converters, wherein the pump laser spectrum is broader than the spectral acceptance bandwidth of at least one of the laser wavelength converters. The broad pump laser spectrum allows some temperature variation in the laser wavelength converters, resulting in a broad temperature acceptance for the whole laser system. The laser system provides stable multi-color laser radiation for applications such as the red-green-blue laser projection TV.
Abstract:
The configurations of an electro-optic Bragg deflector and the methods of using it as a laser Q-switch in a Q-switched laser and in a Q-switched wavelength-conversion laser are provided. As a first embodiment, the electro-optic Bragg deflector comprises an electrode-coated electro-optic material with one of a 1D and a 2D spatially modulated electro-optic coefficient. When a voltage is supplied to the electrodes, the electro-optic material behaves like a Bragg grating due to the electro-optically induced spatial modulation of the refractive index. The second embodiment relates to an actively Q-switched laser, wherein the electro-optic Bragg deflector functions as a laser Q-switch. The third embodiment of the present invention combines the Q-switched laser and a laser-wavelength converter to form a Q-switched wavelength-conversion laser, wherein the EO Bragg deflector can be monolithically integrated with a quasi-phase-matching wavelength converter in a fabrication process.