摘要:
An underwater cutting pelletizer is disclosed wherein a water chamber is circular in plan, an inlet portion is formed on one side in a diametrical direction of the water chamber to introduce cooling water into the water chamber, and an outlet portion is formed on the other side in the diametrical direction of the water chamber to discharge the cooling water from the interior of the water chamber to the exterior, the inlet portion being in a divergent shape in an inflow direction of cooling water. The retention time of pellets in the interior of the water chamber can be made as short as possible.
摘要:
A pelletizing machine for forming pellets from extruded material includes an extruder having at least one exit port and a body defining a cutting chamber through which high-temperature liquid flows, flooding the cutting chamber. The exit port of the extruder opens into the cutting chamber, which includes a cutting section defining a flow path for liquid through the cutting section. A cutter in the cutting section of the cutting chamber is mounted for rotation about an axis generally perpendicular to the first direction and disposed for cutting the extruded material exiting the exit port into the pellets. The axis of rotation of the cutter is parallel to or coincident with the flow path of the cutting section. A method for forming pellets of thermoplastic material with a foaming agent is also disclosed.
摘要:
A method and system for processing a polymer includes providing a molten polymer and processing the polymer into malleable components for delivery to a spirally wound conveying surface. Vibratory forces may be utilized to urge the components along the length of the conveying surface as they undergo crystallizing or drying or crystallizing and drying. Additional supplemental temperature control may be employed to affect crystallization and/or drying of the components along the conveying surface.
摘要:
A center heated die plate for an underwater pelletizer radiates heat outwardly to the extrusion orifices and die faces of the die plate thereby maintaining the die plate and extrusion orifices at an elevated temperature to obtain optimum flow of molten polymer through the extrusion orifices. In one embodiment, a cylindrical heating coil is placed in a hollow central core of the die plate and a plurality of peripheral heating elements are inserted in radial recesses distributed around an outer perimeter of the die plate to create an inner heat zone and an outer heat zone which are separately controllable.
摘要:
A device for granulating plastic melts comprises a granulating head (2) to which a perforated plate (3) provided with melt-discharge openings (10) is attached, which openings are swept by rotating knives (4). The perforated plate (3) is enclosed by a granulating housing (1) which is provided with at least one housing inlet (7) through which a cooling and transport medium (C), preferably water or air, can be supplied to the interior of the granulating housing (1), the cooling and transport medium (C) flowing with a motion component along the inner wall of the granulating housing (1) from the granulating head (2) toward a housing outlet (8) which is arranged in the end region of the granulating housing (1) opposite to the granulating head (2) and through which the cooling and transport medium (C) can be discharged along with the granules (G) produced. The rotating knives (4) are arranged in a knife holding device (6) mounted in a rotatable manner and coupled to the drive shaft (18, 18′) of a motor (9) via a magnetic clutch (15), hence being driven in a contactless manner.
摘要:
A method for starting up or stopping and restarting an underwater pelletizer is described. The method involves inducing partial freeze-off of the polymer melt in the holes of an internally insulated die plate to prevent polymer drool by passing full water flow across the face of the die plate. The method advantageously does not require using hot oil to heat the die plate or decreasing and/or increasing the heating provided to the die plate.
摘要:
Underwater melt pelletizer dies which have a highly thermally conductive pathway from their heating source to the vicinity of the polymer exit end of their die holes and have a thermally insulating material at that end of their die holes have improved operability and can pelletize thermoplastics which are otherwise difficult or impossible to pelletize with such an apparatus.
摘要:
An underwater cutting pelletizer is disclosed wherein a water chamber is circular in plan, an inlet portion is formed on one side in a diametrical direction of the water chamber to introduce cooling water into the water chamber, and an outlet portion is formed on the other side in the diametrical direction of the water chamber to discharge the cooling water from the interior of the water chamber to the exterior, the inlet portion being in a divergent shape in an inflow direction of cooling water. The retention time of pellets in the interior of the water chamber can be made as short as possible.
摘要:
The invention relates to a method for producing a granulate with a low acetaldehyde content and improved processing properties from a high-viscosity polyester melt, wherein the polyester melt strand is fragmented under water at the highest possible temperature, the accompanying water is separated from the granulate with the least possible cooling of the granulate, the low-water granulate obtained in this way is passed after removal of the water directly into a dealdehydisation container and the granulate in the dealdehydisation container is treated with a flow of rinsing air, plus a device for carrying out this method.
摘要:
Expandable plastic granulate can be manufactured continuously with a plastic melt being impregnated using a fluid expanding agent and the impregnated melt being granulated. The plant which includes at least one pressure producing feed apparatus for the melt, a metering apparatus for the expanding agent, contacting and homogenising apparatus for the impregnation of the melt, at least one cooler for the impregnated melt, an underwater granulator and a plant control. An elevated pressure is exerted by the liquid used during granulation to suppress the expanding action of the expanding agent in the not yet solidified granulate. A regulation of the temperature and pressure of the impregnated melt is effected at the inlet of the granulator to influence a heat take-up from the impregnated melt by the cooler or coolers.