Abstract: Method and apparatus for thermally processing polyester pellets, e.g., polyethylene terephthalate pellets, in order to achieve a partial crystallization, whereby the polyester melt is fed to an underwater pelletizer and pelletized, the pellets obtained are fed to a water/solids separating device and the dried pellets are fed at a pellet temperature of greater than 100°C. to an agitation device that the pellets leave at a pellet temperature of over 100°C.

Abstract: The invention relates to a method for thermally treating polyester pellets to obtain partial crystallization, whereby the polyester melt is supplied to an underwater granulating system and granulated; the thus obtained granulate are fed from the underwater granulating system into a water-solids separator. The dried granulate is then fed into a treatment device at a granulate temperature higher than 100 degrees C., without external energy or heat being supplied. The intrinsic heat of the granulate is used as the heat treatment leading to partial crystallization. The crystallization device is embodied as an at least lightly inclined reactor, into which granulate is fed at a temperature higher than 100 degrees C. The granulate passes through the reactor from the loading point to the discharge point under its own weight and exits the reactor with a temperature higher than 130 degrees C.

Abstract: The invention relates to a method for thermally treating polyester pellets to obtain partial crystallization, whereby the polyester melt is supplied to an underwater granulating system and granulated; the thus obtained granulate are fed from the underwater granulating system into a water-solids separator. The dried granulate is then fed into a treatment device at a granulate temperature higher than 100 degrees C., without external energy or heat being supplied. The intrinsic heat of the granulate is used as the heat treatment leading to partial crystallization. The crystallization device is embodied as an at least lightly inclined reactor, into which granulate is fed at a temperature higher than 100 degrees C. The granulate passes through the reactor from the loading point to the discharge point under its own weight and exits the reactor with a temperature higher than 130 degrees C.

Abstract: The invention relates to a process for pelletizing polymer melts, at above ambient pressure, in a pelletizing chamber into which a cutting apparatus has been inserted. In a first step, the pelletizing chamber is flooded with a gas which is inert toward the polymer melt and whose pressure is that at which the pelletizing process is carried out. The polymer melt is then injected into the pelletizing chamber. Finally, the gas is displaced from the pelletizing chamber via a liquid as soon as the polymer melt begins to flow through the cutting apparatus, this melt being cut into pellets.

Abstract: The invention relates to a process for pelletizing polymer melts, at above ambient pressure, in a pelletizing chamber into which a cutting apparatus has been inserted. In a first step, the pelletizing chamber is flooded with a gas which is inert toward the polymer melt and whose pressure is that at which the pelletizing process is carried out. The polymer melt is then injected into the pelletizing chamber. Finally, the gas is displaced from the pelletizing chamber via a liquid as soon as the polymer melt begins to flow through the cutting apparatus, this melt being cut into pellets.

Abstract: The invention relates to a method for thermally treating polyester pellets to obtain a partial crystallization, whereby the polyester melt is delivered to an underwater granulating system and granulated; the thus obtained granulates are carried from the underwater granulating system through a water-solids separator over a short conveying distance; the dried granulates are then delivered to a treatment device at a granulate temperature higher than 100 degrees C. without external energy or heat being supplied. The heat treatment leading to partial crystallization results from the intrinsic heat of the granulates, whereby the treatment device is embodied as an at least lightly inclined reactor, into which the granulates are delivered at a temperature higher than 100 degrees C., the granulates passing through said reactor from the loading point to the discharge point under their own weight and leaving the same at a temperature higher than 130 degrees C.

Abstract: Method and apparatus for thermally processing polyester pellets, e.g., polyethylene terephthalate pellets, in order to achieve a partial crystallization, whereby the polyester melt is fed to an underwater pelletizer and pelletized, the pellets obtained are fed to a water/solids separating device and the dried pellets are fed at a pellet temperature of greater than 100° C. to an agitation device that the pellets leave at a pellet temperature of over 100° C.

Abstract: The invention relates to the assembly of a drive shaft with the cutting head hub of a submersible granulator. Said assembly comprises a connector hood which can be fixed to the drive shaft in such a way that it remains free to move. The connector hood is provided with threading for screwing the cutting head hub onto the drive shaft, said drive shaft being supported on a spherical extremity situated on the inside of the connector hood, and a cogged crown with inner-sided cogs is placed on the cutting head side of the drive shaft. The connector hood has inner-sided cogs which interlace with the cogs on the outer side of the cogged crown. The outer surface of each cog on the cogged crown is convex.

Abstract: Method and apparatus for thermally processing polyester pellets, e.g., polyethylene terephthalate pellets, in order to achieve a partial crystallization, whereby the polyester melt is fed to an underwater pelletizer and pelletized, the pellets obtained are fed to a water/solids separating device and the dried pellets are fed at a pellet temperature of greater than 100° C. to an agitation device that the pellets leave at a pellet temperature of over 100° C.

Abstract: The invention relates to the assembly of a drive shaft with the cutting head hub of a submersible granulator. Said assembly comprises a connector hood which can be fixed to the drive shaft in such a way that it remains free to move. The connector hood is provided with threading for screwing the cutting head hub onto the drive shaft, said drive shaft being supported on a spherical extremity situated on the inside of the connector hood, and a cogged crown with inner-sided cogs is placed on the cutting head side of the drive shaft. The connector hood has inner-sided cogs which interlace with the cogs on the outer side of the cogged crown. The outer surface of each cog on the cogged crown is convex.

Abstract: In a filter changing device with a flow path for the plastic in which one two or more filters can be inserted into the flow path as desired, the invention proposes to fit the filter support in such a way that it can assume a working back rinse and filter change position, in which, in the back rinse position, the plastic is caused to reverse its direction of flow through two interconnected flow channels without permitting air to penetrate into the filter changing device and in which there is free access to one of the filters in the filter changing positions. As the back rinse position can succeed a filter changing position, it is possible to clear the whole filter changing device of occluded air before a plastic processing plant starts production.

Abstract: A tapered insert die plate providing a surface-to-surface contact between the insert and die plate to facilitate removal of and insertion of the insert and substantially improve heat transfer from the outside ring of the die plate to the die insert. The tapered insert is retained in place by hold down bolts which serve as jack bolts to force the insert out of the outer ring of the die plate by insertion into screw threaded holes in the insert to abuttingly engage a flange surface on the outer ring of the die plate to facilitate extraction of the insert when required. The die plate insert includes a plurality of orifices extending therethrough through which molten polymers are extruded in a conventional manner with the tapered surface-to-surface contact between the insert and the die plate providing improved heat transfer from the outside ring of the die plate to the die plate insert as compared with other known techniques of mounting an insert in a die plate.

Abstract: An underwater pelletizer driven from a standard foot mounted electric motor having a standard C-flange attachment in which a pelletizer shaft having a hub is keyed to the motor shaft and held in place by a set screw with the key being welded in a slot in the pelletizer shaft hub to facilitate its manufacture. The pelletizer shaft includes a spring loaded cutter hub enabling automatic blade attachment and compensating for misalignment with the spring loaded cutter hub being keyed to the pelletizer shaft by a key that is welded in a slot in the spring loaded cutter hub to simplify its manufacture and provide a positive and dependable drive connection to enable movement of the portion of the spring loaded cutter hub connected with the blade assembly. The die plate is provided with carbide tiles and the blade assembly includes tungsten carbide blades to provide extended die ware and extended blade ware.