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US 10,093,034 B2Granted
Device and method for the homogenisation of plastics material melts
AssigneeCoperion GmbH
InventorMichael Ahlgrimm
Life of this patent
Estimating the term…
Abstract
A device, to homogenise plastics material melts, has a homogenising element with a plurality of flow channels, which differ with respect to at least one feature from the group length, cross sectional area and cross sectional shape. When flowing through the homogenising element, the plastics material melt is divided into a plurality of part streams, which, in each case, flow through an associated flow channel. When leaving the respective flow channel the part streams have different flow speeds so the plastics material melt is expanded and sheared on transition to a uniform flow. As a result, a homogenisation of the plastics material melt takes place in a simple, efficient and effective manner.
Claims22
A device for the homogenization of plastics material melts, the device comprising:
- a housing;
- at least one housing channel for a plastics material melt to be homogenized, the at least one housing channel being formed in the housing, the at least one housing channel extending from a feed opening to a discharge opening;
- at least one homogenizing element comprising a plurality of flow channels for the plastics material melt to be homogenized, the flow channels extending parallel to one another and the flow channels extending parallel to a conveying direction of the plastics material melt, the flow channels ending offset at a side that is upstream in relation to the conveying direction of the plastics material melt, wherein the flow channels end flush at a side downstream in relation to the conveying direction of the plastics material melt, wherein each of the flow channels has a length defined in a channel longitudinal direction and a cross sectional area defined transverse to the channel longitudinal direction and a cross sectional shape, wherein at least some of the flow channels differ with respect to at least one of length, cross sectional area and cross sectional shape, wherein the at least one homogenizing element is arranged between the feed opening and the discharge opening, the device being configured as a screw machine, wherein at least one treatment element shaft is arranged in the at least one housing channel, the at least one treatment element shaft being rotatably drivable about an associated rotational axis, the at least one treatment element shaft comprising at least one shaft on which treatment elements are non-rotatably arranged consecutively, wherein the at least one homogenizing element extends in the at least one housing channel and the at least one treatment element shaft extends through the least one homogenizing element, wherein a mixing space is formed in a mixing zone downstream of the at least one homogenizing element, wherein no treatment elements are arranged on the at least one shaft, wherein the mixing space has a length LF in the conveying direction and there applies to the length LF in relation to a maximum dimension D of the flow channels perpendicular to the conveying direction:
- LF≥2·D, so that the plastics material melt on transition to a uniform flow is subjected to an expansion and shearing.
1 more element
A method for the homogenization of plastics material melts, the method comprising the following steps:
- providing a device and a plastics material melt, the device comprising a housing, at least one housing channel for the plastics material to be homogenized and at least one homogenizing element, the at least one housing channel being formed in the housing, the at least one housing channel extending from a feed opening to a discharge opening, the at least one homogenizing element comprising a plurality of flow channels for the plastics material melt to be homogenized, the flow channels extending parallel to one another and the flow channels extending parallel to a conveying direction of the plastics material melt, the flow channels ending offset at a side that is upstream in relation to the conveying direction of the plastics material melt, wherein the flow channels end flush at a side downstream in relation to the conveying direction of the plastics material melt, wherein each of the flow channels has a length defined in a channel longitudinal direction and a cross sectional area defined transverse to the channel longitudinal direction and a cross sectional shape, wherein at least some of the flow channels differ with respect to at least one of length, cross sectional area and cross sectional shape, the at least one homogenizing element being arranged between the feed opening and the discharge opening, the device being configured as a screw machine, wherein at least one treatment element shaft is arranged in the at least one housing channel, the treatment element shaft being rotatably drivable about an associated rotational axis, the at least one treatment element shaft comprising at least one shaft on which treatment elements are non-rotatably arranged consecutively, the at least one homogenizing element extending in the at least one housing channel and the at least one treatment element shaft extending through the least one homogenizing element, wherein a mixing space is formed in a mixing zone downstream of the at least one homogenizing element, wherein no treatment elements are arranged on the at least one shaft, the mixing space having a length in the conveying direction, the length of the mixing space being greater than or equal to two times a maximum dimension of the flow channels such that the plastics material melt on transition to a uniform flow is subject to an expansion and shearing, the maximum dimension of the flow channels being perpendicular to the conveying direction;
- conveying the plastics material melt in a conveying direction to at least one homogenizing element;
- passing the plastics material melt through the at least one homogenizing element, the plastics material melt being divided into a plurality of part streams and the part streams flow through a respective associated flow channel and on leaving the respective flow channel have different flow speeds;
- establishing a uniform flow of the plastics material melt in the mixing space downstream of the at least one homogenizing element such that an expansion and shearing of the part streams takes place.
1 more element
A device for the homogenization of plastics material melts, the device comprising:
- a housing;
- a housing channel for a plastics material melt to be homogenized, the housing channel being formed in the housing and the housing channel extending from a feed opening to a discharge opening,
- a homogenizing element comprising a plurality of flow channels for the plastics material melt to be homogenized, wherein each of the flow channels has a length defined in a channel longitudinal direction and a cross sectional area defined transverse to the channel longitudinal direction and a cross sectional shape, wherein at least some of the flow channels differ with respect to at least one of length, cross sectional area and cross sectional shape, wherein the at least one homogenizing element is arranged between the feed opening and the discharge opening, the device being configured as a screw machine, at least one treatment element shaft being arranged in the at least one housing channel, the treatment element shaft being rotatably drivable about an associated rotational axis, the at least one treatment element shaft comprising at least one shaft on which treatment elements are non-rotatably arranged consecutively, wherein the at least one homogenizing element extends in the at least one housing channel and is passed through by the at least one treatment element shaft, wherein a mixing space is formed in a mixing zone downstream of the at least one homogenizing element, wherein no treatment elements are arranged on the at least one shaft in the mixing space, wherein a length of the mixing space in the conveying direction is greater than or equal to two times a maximum dimension of the flow channels such that the plastics material melt is subjected to an expansion and shearing when the plastics material melt transitions to a uniform flow, the maximum dimension of the flow channels being perpendicular to the conveying direction.
Dependencies are inferred from the claim text.