Abstract: An extrusion die (16) including a plurality of pins (38) having side surfaces defining an intersecting array of slots (30) extending axially into the die (16) from a discharge face (34) of the die (16). A plurality of feedholes (28) extend axially from an inlet face (32) of the die (16) opposite to the discharge face (34). The feedholes (28) connect with the slots (30) at intersections (35) within the die (16) to create a flow path from the inlet face (32) to the discharge face (34). A first coating (42) is on at least a portion of the feedholes (28) in a first zone (46) extending over a first axial length of the flow path. A second coating (44) that is different than the first coating (42) is on at least a portion of the side surfaces (37) of the pins (38) in a second zone (48) extending over a second axial length of the flow path. Methods of fabricating an extrusion die (16) and manufacturing a ceramic article (100), such as a honeycomb body, are also disclosed.

Abstract: A honeycomb extrusion die body (401) including inlet (414) and exit (402) faces, and a plurality of pins (406) on the exit face (402) defining a matrix of intersecting wide slots (425) and narrow slots (427). The wide slots (425) have an exit width (W1) greater than an exit width (W2) of the narrow slots (427). The die body (401) further includes feedholes (422) at the inlet face (414) and intersecting with inlet portions (416) to the wide slots (425) and/or the narrow slots (427). Some of the pins (406) defining the wide slots (425) include a first surface indentation feature (430) that is (i) located between the inlet portion (416) and the wide slot exit and (ii) spaced away from the wide slot exit. Some of the pins (406) defining the narrow slots (427) include a second surface indentation feature (434) that is (i) located between the inlet portion and the narrow slot exit and (ii) spaced away from the narrow slot exit.

Abstract: A honeycomb extrusion die (120) includes a die body (342) including an inlet face (315) and an outlet face (341). A plurality of pins (330) extend from the die body (342), wherein the pins (330) are arranged to define primary (312P) and secondary slots (312S). Primary slots (312P) include primary slot inlets (320P) and primary slot outlets (3120) and the secondary slots (312S) include secondary slot inlets (312SI) and secondary slot outlets (312SO). Feedholes (317) extend within the die body (342), the feedholes (317) including feedhole outlets (319), wherein the feedhole outlets (319) intersect only with the primary slot inlets (320P). First surface indentation features (345) extend into side surfaces (332) of the plurality of pins (330) defining the primary slots (312P). The first surface indentation features (345) are spaced from the primary slot outlets (3120). The secondary slots (312S) are devoid of surface indentation features. Other die bodies, extruders, and methods are disclosed.

Abstract: A honeycomb extrusion die body (401) including inlet (414) and exit (402) faces, and a plurality of pins (406) on the exit face (402) defining a matrix of intersecting wide slots (425) and narrow slots (427). The wide slots (425) have an exit width (W1) greater than an exit width (W2) of the narrow slots (427). The die body (401) further includes feedholes (422) at the inlet face (414) and intersecting with inlet portions (416) to the wide slots (425) and/or the narrow slots (427). Some of the pins (406) defining the wide slots (425) include a first surface indentation feature (430) that is (i) located between the inlet portion (416) and the wide slot exit and (ii) spaced away from the wide slot exit. Some of the pins (406) defining the narrow slots (427) include a second surface indentation feature (434) that is (i) located between the inlet portion and the narrow slot exit and (ii) spaced away from the narrow slot exit.

Abstract: Ceramic honeycomb extrusion apparatus and a method of extruding a honeycomb body are disclosed. The honeycomb extrusion apparatus and method utilize a homogenizer plate comprising through holes and a screen support plate comprising screen support plate openings and aligned with the through holes.

Abstract: Extrusion systems and methods with temperature control are disclosed. The ceramic batch material is flowed through a front section wherein the temperature of the batch material is locally adjusted through its perimeter at multiple locations. The temperature-adjusted ceramic batch material is then extruded through the extrusion die to form the extrudate. Temperatures of the extrudate at multiple outer surface locations having different azimuthal positions are measured. The temperature adjustment of the ceramic batch material is then controlled in a first feedback loop to control the shape of the extrudate based on the measured outer surface temperatures. The front section can also be cooled using a second control loop.

Abstract: A control strategy for producing high quality extrudates, including the steps of monitoring the temperature of a ceramic precursor batch by measuring the temperature of the batch material either directly or indirectly by measuring the temperature of a component of the extruder proximate to the die and transmitting the temperature data to an extrusion control system which comprises a master controller (106), at least one slave controller (110) and an optional supervisory controller. The supervisory controller determines batch temperature setpoint (102) in order to achieve the desired temperatures for extruding a certain type of batch material based on real time temperature inputs and stored parameters such as batch composition, process throughput, extruder cooling capacity, and the like.

Abstract: A mixing segment for an extrusion apparatus comprises a shaft and a plurality of plow elements aligned along a helical path extending about a rotation axis of the shaft. Each plow element includes an outer peripheral arcuate ramp extending radially outwardly along the helical path from a root to an outer tip of the plow element. Methods of manufacturing a mixing segment and methods of manufacturing a honeycomb structure with an extrusion apparatus are also provided.

Abstract: A twin screw extruder includes a barrel having a chamber, a discharge port, an extrusion molding die coupled to the discharge port of the barrel, axially extending first and second screw shafts, and a screw shaft support. The screw shaft support includes first and second spacer bearings disposed on the first and second screw shafts, and a first cross member including first and second loops slidably coupled to the first and second spacer bearings. A second cross member is spaced apart from the first cross member by a connection member, and also includes first and second loops slidably coupled to the first and second spacer bearings. The connection member is situated between the first spacer bearing and the second spacer bearing, and connected to the first cross member and the second cross member.

Abstract: A mixing segment for an extrusion apparatus comprises a shaft and a plurality of plow elements aligned along a helical path extending about a rotation axis of the shaft. Each plow element includes an outer peripheral arcuate ramp extending radially outwardly along the helical path from a root to an outer tip of the plow element. Methods of manufacturing a mixing segment and methods of manufacturing a honeycomb structure with an extrusion apparatus are also provided.

Abstract: A twin screw extruder includes a barrel having a chamber, a discharge port, an extrusion molding die coupled to the discharge port of the barrel, axially extending first and second screw shafts, and a screw shaft support. The screw shaft support includes first and second spacer bearings disposed on the first and second screw shafts, and a first cross member including first and second loops slidably coupled to the first and second spacer bearings. A second cross member is spaced apart from the first cross member by a connection member, and also includes first and second loops slidably coupled to the first and second spacer bearings. The connection member is situated between the first spacer bearing and the second spacer bearing, and connected to the first cross member and the second cross member.

Abstract: Extrusion systems and methods with temperature control are disclosed. The ceramic batch material is flowed through a front section wherein the temperature of the batch material is locally adjusted through its perimeter at multiple locations. The temperature-adjusted ceramic batch material is then extruded through the extrusion die to form the extrudate. Temperatures of the extrudate at multiple outer surface locations having different azimuthal positions are measured. The temperature adjustment of the ceramic batch material is then controlled in a first feedback loop to control the shape of the extrudate based on the measured outer surface temperatures. The front section can also be cooled using a second control loop.

Abstract: Methods of extruding a honeycomb body with an extruder comprise the step of feeding batch material to the extruder, wherein the batch material comprises a ceramic or ceramic-forming material. The methods further include the step of rotating at least one mixing screw to cause the batch material to travel along a flow path defined by a barrel of the extruder. The methods further include the step of indexing a carriage to remove a first device from the flow path and introduce a second device into the flow path of the batch material. In one example, the pressure of the batch material changes less than about 25% as a result of indexing the carriage. In addition or alternatively, further methods include the step of reducing a decrease in temperature of the batch material resulting from the step of indexing. In further examples, the method includes the step of pre-filling a second honeycomb extrusion die held by the carriage with a plugging material.

Abstract: A honeycomb extrusion apparatus comprises a die body and a flow control device. The die body comprises an inlet end, an outlet end, a central axis, a first set of feedholes, a second set of feedholes, a set of central slots, and a set of outermost peripheral slots. The first set of feedholes extends from the inlet end to an interior interface portion of the die body. The second set of feedholes extends through the die body from the inlet end to the outlet end. The set of central slots extends from the outlet end to the interior interface portion of the die body. The set of outermost peripheral slots is disposed radially outwardly of the central slots. The interior interface portion of the die body is configured to allow flow of the batch material from the first set of feedholes to the central slots and to the outermost peripheral slots.

Abstract: A control strategy for producing high quality extrudates, including the steps of monitoring the temperature of a ceramic precursor batch by measuring the temperature of the batch material either directly or indirectly by measuring the temperature of a component of the extruder proximate to the die and transmitting the temperature data to an extrusion control system which comprises a master controller (106), at least one slave controller (110) and an optional supervisory controller. The supervisory controller determines batch temperature setpoint (102) in order to achieve the desired temperatures for extruding a certain type of batch material based on real time temperature inputs and stored parameters such as batch composition, process throughput, extruder cooling capacity, and the like.

Abstract: Methods of extruding a honeycomb body with an extruder comprise the step of feeding batch material to the extruder, wherein the batch material comprises a ceramic or ceramic-forming material. The methods further include the step of rotating at least one mixing screw to cause the batch material to travel along a flow path defined by a barrel of the extruder. The methods further include the step of indexing a carriage to remove a first device from the flow path and introduce a second device into the flow path of the batch material. In one example, the pressure of the batch material changes less than about 25% as a result of indexing the carriage. In addition or alternatively, further methods include the step of reducing a decrease in temperature of the batch material resulting from the step of indexing. In further examples, the method includes the step of pre-filling a second honeycomb extrusion die held by the carriage with a plugging material.

Abstract: A honeycomb extrusion apparatus comprises a die body and a flow control device. The die body comprises an inlet end, an outlet end, a central axis, a first set of feedholes, a second set of feedholes, a set of central slots, and a set of outermost peripheral slots. The first set of feedholes extends from the inlet end to an interior interface portion of the die body. The second set of feedholes extends through the die body from the inlet end to the outlet end. The set of central slots extends from the outlet end to the interior interface portion of the die body. The set of outermost peripheral slots is disposed radially outwardly of the central slots. The interior interface portion of the die body is configured to allow flow of the batch material from the first set of feedholes to the central slots and to the outermost peripheral slots.

Abstract: Disclosed is a method and apparatus for forming a circumferential skin surrounding a central cellular structure of an extruded honeycomb article. The method and apparatus may be used to produce defect-free skins and/or skins having large thickness and a high degree of particle alignment thereby preferably exhibiting CTE comparable to the extruded webs. These benefits are achieved by providing a die and method wherein a flow, Q, exiting any two active ones of a plurality of peripheral slots forming the skin is substantially equal. Also disclosed is a thick-skinned ceramic article having a thick extruded skin (ts?>5 tw?) with an I-value comparable to the webs.

Abstract: Honeycomb shapes are extruded from plasticized ceramic powder mixtures by methods that include reducing the core temperature of the charge of the plasticized mixture during transit through the extruder, such methods being carried out utilizing apparatus comprising twin-screw extruders incorporating actively cooled screw elements, whereby temperature-conditioned charges of plasticized material that exhibit reduced core-to-periphery temperature differentials are delivered for extrusion.

Abstract: A twin-screw extruder includes a barrel including a pair of chambers in communication with each other and a discharge port, and an extrusion molding die coupled with respect to the discharge port of the barrel. First and second screw sets are rotatably mounted at least partially within respective ones of the pair of chambers. The first and second screw sets each include a raker blade segment at the discharge port of the barrel that includes at least one flight element with a plurality of serrations extending therethrough. Each of the first and second screw sets also include a lobed kneading segment at the discharge port of the barrel that includes at least one flight element. One of the raker blade segment and the lobed kneading segment is located downstream from another of the raker blade segment and lobed kneading segment. A method of using the twin-screw extruder is also provided.