MATRIX SET FOR PRODUCING FLUID-FILLED PELLETS.

Abstract

A die assembly (5) comprising: (i) a die plate (10) having an inlet surface (15) and an opposing discharge surface (35); (ii) an inlet (30) in the inlet surface (15) and a first axis of symmetry (A) extending through the inlet (30) and perpendicular to the inlet surface (15); (iii) a discharge port (45) in the discharge surface (35) and a second axis of symmetry (B) extending through the discharge port (45) and perpendicular to the discharge surface (35). The first and second axes are spaced apart and parallel to each other. The die assembly (5) includes (iv) an extrusion step (42) seamlessly connecting the inlet (30) and the discharge port (45). A third axis of symmetry (C) extends through the extrusion step (42).The die assembly (5) includes (v) a nozzle (100) mounted on the die plate (10), the nozzle (100) having an injection tip (110) in the extrusion step (42) at the discharge port (45); and (vi) the third axis of symmetry (C) intersects the first axis of symmetry (A) to form an acute angle.

Description

MATRIX ASSEMBLY FOR PRODUCING FLUID-FILLED PELLETS BACKGROUND OF THE INVENTION It is common practice to soak polymer resin pellets in liquid additives to infuse, or otherwise combine, the additive with the polymer pellets before further processing. In the production of plastic coatings for power cables, for example, olefin-based polymer pellets are often soaked in liquid peroxide before molten blending or molten extrusion with other ingredients. Unfortunately, additive soaking of olefin-based polymer pellets has several drawbacks. Many olefin-based polymer pellets require extended soaking times (10 hours or more) to incorporate a sufficient amount of additive into the pellet. These extended soaking times result in additional capital costs for the soaking equipment and decrease production yield rates. The use of porous pellets is known as a way to reduce soaking time for olefin-based polymer pellets. However, porous olefin-based polymer pellets are expensive to produce, which limits their practical use in industry. Porous olefin-based polymer pellets also present problems of lack of Ref. 325913 homogeneity when mixed in the molten state or extruded. Consequently, the technique recognizes the need for polymer resin pellets with an increased surface area to decrease the soaking time of the additive without negatively impacting downstream production stages. The technique also recognizes the need for equipment that can produce polymer resin pellets with an increased surface area for industrial applications that require an additive soaking stage for polymer resin pellets, such as the coating of electrical cables, for example. BRIEF DESCRIPTION OF THE INVENTION The present description provides a die assembly. In one embodiment, the die assembly includes: (i) a die plate having an inlet surface and an opposing discharge surface; (ii) an inlet on the inlet surface and a first axis of symmetry extending through the inlet and perpendicular to the inlet surface; (iii) a discharge port on the discharge surface and a second axis of symmetry extending through the discharge port and perpendicular to the discharge surface. The second axis of symmetry is spaced and parallel to the first axis of symmetry. The die assembly includes (iv) an extrusion step seamlessly connecting the inlet and the discharge port. A third axis of symmetry extends through the extrusion step.The die assembly includes (v) a nozzle mounted on the die plate, the nozzle having an injection tip in the extrusion step at the discharge port; and (vi) the third axis of symmetry intersects the first axis of symmetry at the inlet to form an acute angle. BRIEF DESCRIPTION OF THE FIGURES Figure 1A is a perspective view of an upstream face of a matrix plate according to one modality of the present description. Figure IB is a perspective view of a downstream face of the matrix plate according to one modality of the present description. Figure 2 is an exploded view of a matrix assembly according to one modality of the present description. Figure 3 is a cross-sectional view of the matrix assembly taken along line 3-3 of Figure 2. Figure 4A is an enlarged view of Area 4A from Figure 3. Figure 4B is an enlarged view of Area 4B from Figure 4A. Figure 4C is an enlarged cross-sectional view of a matrix assembly including an output plate according to one modality of the present description. Figure 5 is the cross-sectional view of Figure 4A showing the flow of extrudate through the die assembly and the production of fluid-filled pellets according to one modality of the present description. Figure 6 is a perspective view of a hollow pellet, according to one modality of the present description. Figure 7A is a cross-sectional view of the pellet as seen along line 7A-7A of Figure 6. Figure 7B is a cross-sectional view of the pellet as seen along line 7B-7B of Figure 6. Figure 8 is an exploded view of the pellet in Figure 6. Figure 9 is a perspective view of a closed pellet, according to one modality of the present description. Figure 10 is a cross-sectional view of the closed pellet as seen along line 10-10 of Figure 9. DETAILED DESCRIPTION OF THE INVENTION DEFINITIONS For the purposes of United States patent practice, the contents of any patent, patent application, or publication referenced herein are incorporated by reference in their entirety (or their equivalent U.S. version is so incorporated by reference), especially with respect to the description of definitions (to the extent they are not inconsistent with any of the definitions specifically provided in this description) and general knowledge of the art. The numerical intervals described herein include all values ​​from the lowest to the highest inclusive. With respect to intervals containing explicit values ​​(e.g., 1 or 2, or 3 to 5, or 6, or 7), any subinterval between any two explicit values ​​is included (e.g., 1 to 2; 2 to 6; 5 to 7; 3 to 7; 5 to 6; etc.). The terms "comprising," "including," "having," and their derivatives are not intended to exclude the presence of any additional component, step, or process, whether specifically described or not. For the avoidance of doubt, all compositions claimed using the term "comprising" may include any additive, adjuvant, or additional compound (whether polymerized or not) unless otherwise stated. Conversely, the term "consisting essentially of" excludes from the scope of any further enumeration any other component, step, or process, except those not essential to performance. The term "consisting of" excludes any component, step, or process not specifically defined or enumerated. The term "or," unless otherwise stated, refers to the members listed individually as well as in any combination.The use of the singular includes the use of the plural and vice versa. Unless otherwise stated, implied from the context, or customary in the art, all parts and percentages are based on weight, and all testing methods are current as of the date of submission of this description. Blend, polymer blend, and similar terms refer to a combination of two or more polymers. The blend may be miscible or immiscible. The combination may or may not have phase separation. Such a combination may or may not contain one or more domain configurations, as determined by transmission electron spectroscopy, light scattering, X-ray scattering, and any other method known in the art. An ethylene-based polymer is a polymer containing more than 50 percent by weight of polymerized ethylene monomer (based on the total amount of polymerizable monomers) and may optionally contain at least one comonomer. Ethylene-based polymers include ethylene homopolymers and ethylene copolymers (i.e., units derived from ethylene and one or more comonomers). The terms ethylene-based polymer and polyethylene can be used interchangeably. Non-limiting examples of ethylene-based polymers (polyethylene) include low-density polyethylene (LDPE) and linear polyethylene.Non-limiting examples of linear polyethylene include linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (ULDPE), very low-density polyethylene (VLDPE), multi-component ethylene-based copolymer (EPE), ethylene / α-olefin multiblock copolymers (also called olefin block copolymers (OBC)), single-site catalyzed linear low-density polyethylene (m-LLDPE), substantially linear or linear plastomers / elastomers, medium-density polyethylene (MDPE), and high-density polyethylene (HDPE).Polyethylene can generally be produced in gas-phase fluidized bed reactors, liquid-phase suspension process reactors, or liquid-phase solution process reactors using a heterogeneous catalytic system, such as the Ziegler-Natta catalyst, or a homogeneous catalytic system comprising Group 4 transition metals and ligand structures, such as metallocene, metal-centered non-metallocene heteroaryl, heterovalent aryloxy ether, phosphinimine, and others. Combinations of heterogeneous and / or homogeneous catalysts can also be used in both single-reactor and dual-reactor configurations. In one embodiment, the ethylene-based polymer does not contain a polymerized aromatic comonomer itself. Ethylene plastomers / elastomers are substantially linear, or linear, ethylene / α-olefin copolymers containing a heterogeneous short-chain branching distribution comprising ethylene-derived units and units derived from at least one C3-C10 α-olefin comonomer, at least one C4-C8 α-olefin comonomer, or at least one Ce-Cs α-olefin comonomer. Ethylene plastomers / elastomers have a density of 0.870 g / cc, 0.880 g / cc, or 0.890 g / cc to 0.900 g / cc, 0.902 g / cc, 0.904 g / cc, 0.909 g / cc, 0.910 g / cc, or 0.917 g / cc. Non-limiting examples of ethylene plastomers / elastomers include AFFINITY™ plastomers and elastomers (available through The Dow Chemical Company), EXACT™ plastomers (available through ExxonMobil Chemical), Tafmer™ (available through Mitsui), Nexlene™ (available through SK Chemicals Co.) and Lucene™ (available through LG Chem Ltd.). High-density polyethylene (or HDPE) is an ethylene homopolymer or an ethylene / α-olefin copolymer that has at least one C4-C10 α-olefin comonomer, or one C4-C8 α-olefin comonomer, and a density greater than 0.94 g / cc, or 0.945 g / cc, or 0.95 g / cc, or 0.955 g / cc to 0.96 g / cc, or 0.97 g / cc, or 0.98 g / cc. HDPE can be a monomodal copolymer or a multimodal copolymer. A monomodal ethylene copolymer is an ethylene / C4-C10 α-olefin copolymer that has a distinct peak on gel permeation chromatography (GPC) that shows the molecular weight distribution. A multimodal ethylene copolymer is an ethylene / Ci-Ci α-olefin copolymer that has at least two distinct peaks on a GPC showing the molecular weight distribution. Multimodal includes copolymers with two peaks (bimodal) as well as copolymers with more than two peaks.Non-limiting examples of HDPE include DOW™ High Density Polyethylene (HDPE) resins, ELITE™ Enhanced Polyethylene resins, and CONTINUUM™ Bimodal Polyethylene resins, each available from The Dow Chemical Company; LUPOLEN™, available from LyondellBasell; as well as HDPE products from Borealis, Ineos, and ExxonMobil. An interpolymer (or copolymer) is a polymer prepared by the polymerization of at least two different monomers. This generic term includes copolymers, generally used to refer to polymers prepared from two different monomers, and polymers prepared from more than two different monomers, for example, terpolymers, tetrapolymers, etc. Low-density polyethylene (or LDPE) consists of an ethylene homopolymer, or an ethylene / α-olefin copolymer comprising at least one C3-C10 α-olefin, preferably C3-C4, having a density of 0.915 g / cc to 0.940 g / cc and containing long-chain branching with a wide molecular weight distribution (MWD). LDPE is typically produced by high-pressure free-radical polymerization (tubular reactor or autoclave with a free-radical initiator). Non-limiting examples of LDPE include MarFlex™ (Chevron Phillips), LUPOLEN™ (LyondellBasell), as well as LDPE products from Borealis, Ineos, ExxonMobil, and others. Linear low-density polyethylene (or LLDPE) is a linear ethylene / α-olefin copolymer containing a heterogeneous short-chain branching distribution comprising ethylene-derived units and units derived from at least one C3-C10 α-olefin comonomer, at least one C4-C8 α-olefin comonomer, or at least one CgCs α-olefin comonomer. LLDPE is characterized by little, if any, long-chain branching, in contrast to conventional LDPE. LLDPE has a density ranging from 0.910 g / cc, 0.915 g / cc, 0.920 g / cc, or 0.925 g / cc to 0.930 g / cc, 0.935 g / cc, or 0.940 g / cc. Non-limiting examples of LLDPE include TUFLIN™ linear low-density polyethylene resins and DOWLEX™ polyethylene resins, each available through The Dow Chemical Company; and MARLEX™ polyethylene (available through Chevron Phillips). The multicomponent ethylene-based copolymer (or EPE) comprises units derived from ethylene and units derived from at least one Ca-Cic aolefin comonomer, at least one C4-C8 α-olefin comonomer, or at least one Ce-Cs α-olefin comonomer, as described in patent references USP 6,111,023; USP 5,677,383; and USP 6,984,695. EPE resins have a density of 0.905 g / cc, or 0.908 g / cc, or 0.912 g / cc, or 0.920 g / cc to 0.926 g / cc, or 0.929 g / cc, or 0.940 g / cc or 0.962 g / cc. Non-limiting examples of EPE resins include ELITE™ enhanced polyethylene and ELITE AT™ advanced technology resins, each available from The Dow Chemical Company; SURPASS™ polyethylene (PE) resins, available from Nova Chemicals; and SMART™ available from SK Chemicals Co. An olefin-based polymer, or polyolefin, is a polymer containing more than 50 percent by weight of polymerized olefin monomer (based on the total amount of polymerizable monomers) and may optionally contain at least one comonomer. Non-limiting examples of olefin-based polymers include ethylene-based polymers and propylene-based polymers. An olefin and similar terms refer to hydrocarbons consisting of hydrogen and carbon, whose molecules contain a pair of carbon atoms linked by a double bond. A polymer is a compound prepared by the polymerization of monomers, whether of the same or different types, which in their polymerized form provide the multiple and / or repeating units, or mer units, that constitute a polymer. Therefore, the generic term polymer encompasses the term homopolymer, usually used to refer to polymers prepared from a single type of monomer, and the term copolymer, usually used to refer to polymers prepared from at least two types of monomers. It also encompasses all forms of copolymer, for example, random, block, etc. The expressions ethylene / α-olefin polymer and propylene / α-olefin polymer indicate a copolymer, as described above, prepared from the polymerization of ethylene or propylene, respectively, and one or more additional polymerizable α-olefin monomers.It is noted that, while a polymer is often referred to as being made from one or more specified monomers, based on a specified monomer or monomer type, containing a specified monomer content, or similar, in this context the term monomer is understood to refer to the polymerized remnant of the specified monomer and not to the unpolymerized species. Generally, polymers herein are referred to as being based on units that are the polymerized form of a corresponding monomer. Single-site catalyzed linear low-density polyethylenes (or m-LLDPE) are linear ethylene / α-olefin copolymers containing a homogeneous short-chain branching distribution comprising ethylene-derived units and units derived from at least one C3-C10 α-olefin comonomer, at least one C4-C8 α-olefin comonomer, or at least one C5-C8 α-olefin comonomer. m-LLDPE has a density of 0.913 g / cc, 0.918 g / cc, or 0.920 g / cc to 0.925 g / cc or 0.940 g / cc. Non-limiting examples of m-LLDPE include EXCEED™ metallocene PE (available from ExxonMobil Chemical), LUFLEXEN™ m-LLDPE (available from LyondellBasell), and ELTEX™ PF m-LLDPE (available from Ineos Olefins & Polymers). Each of ultra-low-density polyethylene (or ULDPE) and very-low-density polyethylene (or VLDPE) is a linear ethylene / α-olefin copolymer containing a heterogeneous short-chain branching distribution comprising ethylene-derived units and units derived from at least one C3-C10 α-olefin comonomer, or at least one C4-C8 α-olefin comonomer, or at least one CeCs α-olefin comonomer. ULDPE and VLDPE each have a density of 0.885 g / cc, or 0.90 g / cc to 0.915 g / cc. Non-limiting examples of ULDPE and VLDPE include ALTANE™ ULDPE resins and FLEXOMER™ VLDPE resins, each available through The Dow Chemical Company. Melt blending is a process in which at least two components are combined or otherwise mixed together, and at least one of the components is in a molten state. Melt blending can be carried out by one or more of various known processes, such as batch blending, extrusion blending, extrusion molding, and the like. Melt-blended compositions are compositions formed by the melt blending process. Thermoplastic polymer and similar terms refer to a linear or branched polymer that can be softened and made fluid repeatedly when heated and can return to a solid state when cooled to room temperature. A thermoplastic polymer typically has an elastic modulus greater than 68.95 MPa (10,000 psi) measured according to ASTM D638-72. Furthermore, a thermoplastic polymer can be molded or extruded into an article of any predetermined shape when heated to its softened state. Thermoset polymer, thermoset polymer, and similar terms indicate that, once cured, the polymer cannot be further softened or molded by heat. Thermoset polymers, once cured, are space-network polymers and are highly cross-linked to form rigid, three-dimensional molecular structures. This description provides a die assembly. The die assembly includes a die plate having an inlet surface and a discharge surface. The discharge surface and the inlet surface are on opposite sides of the die plate. The inlet surface includes an inlet. A first axis of symmetry, perpendicular to the inlet surface, extends through the inlet. The discharge surface includes a discharge port. A second axis of symmetry, perpendicular to the discharge surface, extends through the discharge port. The first and second axes of symmetry are spaced apart and parallel to each other. The die plate includes an extrusion step extending from the inlet to the discharge port (i.e., the extrusion step seamlessly connects the inlet and the discharge port). The die plate includes a third axis of symmetry extending through the extrusion step.The die assembly includes a nozzle mounted on the die plate. The nozzle has an injection tip. The injection tip of the nozzle is located in the extrusion pass at the discharge port. The third axis of symmetry intersects the first axis of symmetry at the inlet to form an acute angle. Matrix plate With reference to the figures, and initially to Figure 1A, the die assembly 5 includes a die plate 10. Figure 1A shows the die plate 10, which has an inlet surface 15 and a circular inlet 30. Inlet 30 is located in the center of the die plate 10 and opens into it. An inlet plate 25 has an upstream face that is circular. Inlet 30 and inlet plate 25 form concentric circles. The inlet plate 25 includes an inlet port 27, which is conical in shape. The inlet port 27 has a downstream end that is circular and aligned with inlet 30. The die assembly 5 can be used, for example, with an extruder (not shown) to form fluid-filled pellets, as described herein. Inlet port 27 and inlet 30 are adapted to receive an extrudate (not shown) from the extruder.The term "adapted to receive," as used herein, indicates that the shape and dimensions of the inlet port 27 and inlet 30 allow the extrudate to flow from the extruder through inlet 30 and into the die assembly 5 without leakage. The extruder is operatively connected to the die assembly 5 on an upstream face 20 of the die plate 10, as shown in Figure 1A. The terms upstream and downstream refer to the spatial location of two objects (or components) relative to each other. Upstream indicates a position closer to the source of the extrudate (e.g., the extruder), while downstream refers to a position farther from the source. In other words, with respect to two objects, the first object being upstream of the second object means the first object is closer to the source of the extrudate than the second object is downstream. In one embodiment, the die plate 10 is made of one or more metals. Non-limiting examples of suitable metals include steel, stainless steel, metal composites, and combinations thereof. In one embodiment, the die plate 10 is made of P-20 steel. In another embodiment, the die plate 10 is made of one or more metal composites. Figure IB shows the discharge surface 35 and discharge port 45 of the matrix plate 10. The discharge surface 35 is located on a downstream face 40 of the matrix plate 10 as shown in Figure IB. Figure 2 shows a fluid source 60, an adapter screw 80, and a nozzle 100. The fluid source 60 houses a fluid 50 and includes an insertion end 62. The fluid 50 is understood to be distinct from the extrudate entering the inlet 30 from the extruder. The adapter screw 80 is attached to a downstream side of the inlet plate 25. The nozzle 100 is attached to the adapter screw 80. The nozzle 100 is mounted on the die plate 10 by means of the adapter screw 80 and the inlet plate 25. Figure 4A shows the array assembly 5 with the nozzle 100 mounted on the array plate 10. A first axis of symmetry A is shown. The first axis of symmetry A extends through the inlet 30 and is perpendicular to a surface of the plate 32. The surface of the plate 32 occupies a plane (not shown) defined by an interface between the inlet plate 25 and the array plate 10. In one mode, the first axis of symmetry A bisects the inlet 30. Figure 4A shows a second axis of symmetry B, the second axis of symmetry B extends through the discharge port 45. The second axis of symmetry B is perpendicular to the discharge surface 35. The second axis of symmetry B is spaced and parallel to the first axis of symmetry A, as shown in Figure 4A. Figure 4A shows an extrusion step 42, which seamlessly connects the inlet 30 and the discharge port 45. A downstream end of the extrusion step 42 surrounds a downstream section of the nozzle 100. A third axis of symmetry C extends through the inlet 30, the extrusion step 42, and the discharge port 45. An upstream portion of the third axis of symmetry C is arranged parallel to an upstream portion of the extrusion step 42. The third axis of symmetry C intersects the first axis of symmetry A to form a vertex point F and an acute angle D at the inlet 30. The acute angle D is distinguished from the obtuse angle G where the value of the acute angle D is less than 90°, the value of the obtuse angle G is greater than 90°, and the sum of the values ​​of the acute angle D and the obtuse angle G is exactly 180°.The third axis of symmetry C also intersects the second axis of symmetry B to form a vertex point H and an acute angle E at the discharge port 45. The acute angle E is distinguished from the obtuse angle I where the value of the acute angle E is less than 90°, the value of the obtuse angle I is greater than 90°, and the sum of the value of the acute angle E and the value of the obtuse angle I is exactly 180°. In one modality, the value of acute angle D is the same as the value of acute angle E. Figure 4A shows an extrusion angle J. The extrusion angle J is the angle between the slope of the extrusion channel 42 and a horizontal line defined by the surface of plate 32 (i.e., the interface of the inlet plate 25 and the die plate 10, as described herein). The value of acute angle D is 90 degrees minus the value of extrusion angle J. In other words, the value of acute angle D is the value of extrusion angle J subtracted from 90 degrees. The value of acute angle E is 90 degrees minus the value of extrusion angle J. In other words, the value of acute angle E is the value of extrusion angle J subtracted from 90 degrees. Figure 4A shows a near end of nozzle 104 located at the upstream end of nozzle 100. The near end of nozzle 104 is in fluid communication with fluid source 60. A distal end of nozzle 108 is located at the downstream end of nozzle 100. The near end of nozzle 104 and the distal end of nozzle 108 are at opposite ends of nozzle 100. The distal end of nozzle 108 includes an injection tip 110, which has an opening in its center. The injection tip 110 is located in the extrusion passage 42 at the discharge port 45. The nozzle 100 includes an annular channel 70. The annular channel 70 extends from the near end of the nozzle 104 through the nozzle body 100 to the opening of the injection tip 110. The annular channel 70 is fluidly connected to the fluid source 60 through the fluid channel 64. In one embodiment, nozzle 100 is a stepped nozzle. The term stepped nozzle, as used herein, refers to a nozzle having two or more distinct inside diameters. In one embodiment, nozzle 100 is a stepped nozzle having three distinct inside diameters. In another embodiment, Figure 4B shows a near inside diameter K, a mean inside diameter L, and a tip inside diameter M, where the near inside diameter K is larger than the mean inside diameter L, and the mean inside diameter L is larger than the tip inside diameter M. The near end of nozzle 104 includes a near inside diameter K (or interchangeably referred to as PID) as shown in Figure 4B. The injection tip 110 includes a tip inside diameter M (or interchangeably referred to as TID). The PID is larger than the tip inside diameter H. In one mode, the PID is 2.2 millimeters (mm), 2.4 mm, 2.6 mm, 2.8 mm, 3.0 mm to 3.4 mm, 3.6 mm, 3.8 mm, or 4.1 mm. In an additional mode, the PID is 2.2 to 4.1 mm, 2.6 to 3.6 mm, or 3.0 to 3.4 mm. In one mode, the TID is 0.22 mm, 0.25 mm, 0.28 mm, 0.30 mm to 0.40 mm, 0.42 mm, 0.45 mm, or 0.48 mm. In an additional mode, the TID is 0.22 to 0.48 mm, 0.24 to 0.40 mm, or 0.25 to 0.35 mm. A mean inside diameter L is located in a central part of the nozzle. In one embodiment, the mean inside diameter L is 1.0 mm, 1.2 mm, 1.4 mm, 1.6 mm to 1.8 mm, 2.0 mm, 2.2 mm, or 2.4 mm. In an additional embodiment, the mean inside diameter L is 1.0 to 2.4 mm, 1.2 to 2.2 mm, or 1.6 to 1.8 mm. An outer diameter of the N tip is found on the 110 injection tip. In one embodiment, the outer diameter of the N tip is 0.45 mm, 0.50 mm, 0.55 mm, 0.60 mm to 0.90 mm, 0.95 mm, 1.0 mm, or 1.1 mm. In an additional embodiment, the outer diameter of the N tip is 0.45 to 1.1 mm, 0.50 to 1.0 mm, or 0.60 to 0.90 mm. Figures 4A-4B show that the injection tip 110 is located at the distal end of the nozzle 108. The injection tip 110 is located in the extrusion passage 42 at the discharge port 45. In other words, the injection tip 110 is completely surrounded by the extrusion passage 42. As best shown in Figure 4B, at the discharge port 45, the injection tip 110 is located in a recoil position O that is upstream of the discharge face 35, so that the injection tip 110 is not coplanar with the discharge face 35. The extrusion passage 42 completely surrounds the injection tip 110 at the recoil position O. Figure 4B shows the recoil position O for the injection tip 110. In one embodiment, the recoil position O is 0.02 mm or 0.03 mm or 0.05 mm to 0.15 mm or 0.18 mm or 0.22 mm upstream of the discharge face 35. In another embodiment, the recoil position O is 0.02 mm to 0.22 mm or 0.03 mm to 0.18 mm or 0.05 mm to 0.15 mm upstream of the discharge face 35. Figure 5 shows an extrudate 210 in extrusion pass 42. The extrudate is shown flowing from the extruder (not shown) and passing through inlet 30 at arrow 5.1. The extrudate enters extrusion pass 42 and is evenly distributed throughout the entire extrusion pass 42. As indicated by arrows 5.1 and 5.2, the extrudate flows through extrusion pass 42 and around the distal end of nozzle 108 and injection tip 110. Figure 5 shows fluid 50. Fluid 50 is depicted passing from fluid source 60 through fluid channel 64 at arrow 5.3. Fluid 50 enters the annular channel 70 within nozzle 100 as indicated by arrow 5.4. The passage of extrudate 210 and the passage of fluid 50 occur simultaneously or substantially simultaneously. Downstream of arrow 5.5, fluid 50 enters the injection tip and is then injected into the extrudate as it exits discharge port 45 to form a fluid-filled extrudate 225. Figure 5 shows a rotary blade apparatus 200. The rotary blade apparatus 200 is in operational communication with the discharge port 45 of the discharge surface 35. The rotary blade apparatus 200 repeatedly cuts the fluid-filled extrudate 225 emerging from the discharge port 45, while it is still in a plastic state, transversely to the flow direction of the fluid-filled extrudate 225 to form fluid-filled pellets 230 as indicated by arrow 5.6. The spacing between cuts and the cutting frequency provide control over the size of the resulting fluid-filled pellets 230. Without adhering to any particular theory, the extrudate viscosity, the pullback distance, and the cutting frequency are adjusted to produce fluid-filled pellets 230 that have two open ends, one open end, or no open ends, the latter being pellets with two closed ends. Figure 4C shows an embodiment of the present description that includes an outlet plate 300 attached to the discharge face 45 of the die plate 10. In one embodiment, the outlet plate 300 is made of a metal having a higher hardness value compared to the hardness value for the die plate material 10. The hardness of the steel is conveyed using the Rockwell hardness scale (e.g., HRA, HRB, HRC, etc.). In one configuration, the 300 output plate is made of 01 tempered steel. The 300 outlet plate includes an outlet face 310 and an outlet port 320 located on the outlet face 310. The 300 outlet plate also includes an outlet channel 330, which seamlessly connects the discharge port 45 to the outlet port 320. The injection tip 110 extends into the outlet channel 330, and the outlet channel 330 surrounds the injection tip 110. The injection tip 110 is located at a retraction position P that is upstream of the outlet face 310, such that the injection tip 110 is not coplanar with the outlet face 310. The extrudate passes from the extrusion pass 42 to the outlet channel 330 and surrounds the injection tip 110 at the retraction position P. In one embodiment, the retraction position P is either 0.02 mm or 0.03 mm. 0.05 mm to 0.15 mm, or 0.18 mm or 0.22 mm upstream of the outlet face 310. In another embodiment, the backset position P is 0.02 mm to 0.22 mm or 0.03 mm to 0.18 mm or 0.05 mm to 0.15 mm upstream of the outlet face 310. The injection tip injects fluid 50 into the extrudate as the extrudate exits the outlet port 320 to form a fluid-filled extrudate 225. The rotary blade apparatus 200 cuts the fluid-filled extrudate 225 emerging from the outlet port 320 to form fluid-filled pellets 230. In one mode, the 200 rotary blade apparatus is selected from an oscillating blade, a reciprocating blade, a rotary blade, a rotary circular blade, a wet-cut underwater strand pelletizer, and a die cutter. In one embodiment, the downstream face of the die assembly 5 and the rotary blade apparatus 200 are fully immersed in a process fluid. The process fluid is selected from water, an oil, a heat transfer fluid, a lubricant, or a combination thereof. F1 uido Nozzle 100 injects fluid 50 into the extrudate to form the fluid-filled extrudate 225 as shown in Figure 5. Non-limiting examples of a suitable fluid for use as fluid 50 include a gas, a liquid, a fluid thermoplastic polymer, or a combination thereof. In one embodiment, the gas used as fluid 50 is air, an inert gas (nitrogen or argon, for example), or a combination of these. In a further embodiment, the gas used as fluid 50 is air. In a further embodiment, the gas used as fluid 50 is nitrogen. In one configuration, fluid 50 is nitrogen gas. The nitrogen gas pressure is 5 psig, 10 psig, 20 psig to 30 psig, 50 psig, or 200 psig. In an additional configuration, the nitrogen gas pressure is 5 to 200 psig, 10 to 50 psig, or 20 to 30 psig. In one mode, the nitrogen gas has a flow rate of 2 milliliters per minute (mL / min) or 5 mL / min or 10 psig or 20 mL / min or 30 mL / min to 40 mL / min or 50 mL / min or 100 mL / min or 200 mL / min. In an additional mode, the nitrogen flow rate is 2 to 200 mL / min or 5 to 100 mL / min or 10 to 50 mL / min. In one embodiment, Fluid 50 is a liquid. Non-limiting examples of suitable liquids include a peroxide, a curing co-agent, a silane, an antioxidant, a UV stabilizer, a processing aid, a coupling agent, and combinations thereof. In another embodiment, the liquid used as Fluid 50 is blended into a polymer carrier. In a further embodiment, other components are added to Fluid 50, these other components accelerating the solidification of Fluid 50. Non-limiting examples of other suitable components include oligomers, nucleating agents, and combinations thereof. Fluid 50 may comprise two or more modalities described in this document. Pellets Figure 6 shows a pellet produced by die assembly 5. Not wishing to be bound by any particular theory, the viscosity of the extrudate determines the arrangement of the ends of the fluid-filled pellet. In the absence of interactions with a second object, higher-viscosity extrudates exhibit less flow after the rotating blade apparatus 200 cuts the fluid-filled extrudate 225. Therefore, the ends of higher-viscosity extrudates have a greater tendency to remain open compared to the ends of lower-viscosity extrudates. However, higher-viscosity extrudates exhibit a greater tendency to be dragged along with the blade (i.e., shearing behavior) compared to lower-viscosity extrudates.Shearing behavior gives higher viscosity extrudates a greater tendency to close around the blade and form a closed end compared to lower viscosity extrudates. The phenomenon of the extrudate being sheared and pulled along with the blade to form a closed end is called rounding, and a higher incidence of closed ends is referred to as major rounding. In one mode, the recoil distance of the 110 injection tip influences the amount of rounding. In one embodiment, the retreat distance and extrusion viscosity are selected so that the die assembly 5 produces a fluid-filled pellet 610 having open ends as shown in Figure 6. The pellet 610 includes a body 620. The body 620 includes a first open end 615 and a second open end 625. The pellet 610 includes a channel 630. The channel 630 extends through the body 620 from the first open end 615 to the second open end 625. The pellet 610 with the body 620 and the channel 630 extending through it is hereafter referred to interchangeably as a hollow pellet. In one embodiment, the body 620 is cylindrical. The body 620 includes the first open end 615 and the second open end 625, both of which are circular. The first open end 615 and the second open end 625 are located on opposite sides of the body 620. An axis of symmetry Q is located at the center of circles formed by the ends 615 and 625, as shown in Figure 6. The pellet 610 includes a channel 630 that is parallel or substantially parallel to the axis of symmetry Q. The channel 630 is cylindrical or generally cylindrical and is located at the center of the body 620. The channel 630 extends the entire length of the body 620. The channel 630 extends from the first open end 615 to the second open end 625. Body 620 has a circular or generally circular cross-sectional shape. Body 620 also has a cylindrical or generally cylindrical shape. It is understood that the circular and cross-sectional shape of Body 620 may be altered (i.e., squeezed, pressed, or packed) due to forces imparted on pellet 610 during industrial-scale production and / or handling of the pellet while it is still in a molten state. Consequently, the cross-sectional shape of Body 620 may be more elliptical than circular, hence the definition of generally circular cross-sectional shape. Body 620 and channel 630 each have a respective diameter: body diameter 640 and channel diameter 645. The term diameter, as used herein, is the greatest length between two points on the surface of the body / channel that extends through the center, via the axis of symmetry Q, of the body / channel. In other words, when pellet 610 has an elliptical shape (as opposed to a circular shape), the diameter is the major axis of the ellipse. In one modality, the shape of body 620 resembles a hockey puck. Figure 7A shows a body diameter 640 and a channel diameter 645 for pellet 610. In one embodiment, the body diameter 640 is 0.7 millimeters (mm), 0.8 mm, 0.9 mm, 1.0 mm, 1.5 mm, 3.7 mm, 4.0 mm, 4.2 mm, 4.6 mm, or 5.0 mm. In an additional embodiment, the body diameter 640 is 0.7 to 5.0 mm, 0.8 to 4.2 mm, or 1.0 to 4.0 mm. In one embodiment, the diameter of channel 645 is 0.10 mm, 0.13 mm, 0.15 mm, or 0.18 mm to 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.6 mm, or 1.8 mm. In an additional embodiment, the diameter of channel 645 is 0.10 to 1.8 mm, 0.15 to 1.6 mm, 0.18 to 1 mm, 0.18 to 0.8 mm, or 0.18 to 0.6 mm. The pellet has a channel diameter-to-body diameter (CBD) ratio. The term channel diameter-to-body diameter ratio (or CBD), as used herein, refers to the result obtained by dividing the channel diameter by the body diameter (i.e., the CBD is the quotient of the channel diameter and the body diameter). For example, when the channel diameter is 2.0 mm and the body diameter is 7.0 mm, the CBD ratio is 0.29. In one modality, the CBD ratio is 0.03, 0.05, 0.07, 0.11, 0.13, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, or 0.5. In another additional modality, the CBD ratio is 0.03 to 0.5 or 0.05 to 0.45 or 0.05 to 0.25 or 0.05 to 0.15 or 0.11 to 0.15. Figure 7B shows a length 635 for body 620. In one embodiment, length 635 is 0.4 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm to 1.9 mm, 2 mm, 2.2 mm, 2.5 mm, 3 mm, 3.3 mm, 3.5 mm, or 4 mm. In an additional embodiment, length 635 is 0.4 to 4 mm, 0.8 to 3.5 mm, 1 to 3.5 mm, 1.4 to 2.5 mm, or 1.5 to 1.9 mm. In one embodiment: (i) the length 635 is from 0.4 mm or 0.8 mm or 1 mm or 1.2 mm or 1.4 mm or 1.5 mm or 1.6 mm or 1.7 mm to 1.9 mm or 2 mm or 2.2 mm or 2.5 mm or 3 mm or 3.3 mm or 3.5 mm or 4 mm; (ii) the body diameter 640 is from 0.7 millimeters (mm) or 0.8 mm or 0.9 mm or 1.0 mm or 1.5 mm to 3.7 mm or 4.0 mm or 4.2 mm or 4.6 mm or 5.0 mm; and (iii) the diameter of channel 645 is from 0.10 mm or 0.13 mm or 0.15 mm or 0.18 mm to 0.3 mm or 0.4 mm or 0.5 mm or 0.6 mm or 0.8 mm or 1 mm or 1.6 mm or 1.8 mm. In a further embodiment: (i) the length 635 is from 0.4 to 4 mm or from 0.8 to 3.5 mm or from 1 to 3.5 mm or from 1.4 to 2.5 mm or from 1.5 to 1.9 mm; (ii) the diameter of body 640 is from 0.7 to 5.0 mm or from 0.8 to 4.2 mm or from 1.0 to 4.0 mm; and (iii) the diameter of channel 645 is from 0.10 to 1.8 mm or from 0.15 to 1.6 mm or from 0.18 to 1 mm or from 0.18 to 0.8 mm or from 0.18 to 0.6 mm. Returning to Figure 6, a first face 655 of the pellet 610 is shown. The first face 655 is located at the first open end 615. A first hole 650 is located in the center of the first face 655. The first hole 650 is circular, or generally circular in shape, and opens into the channel 630. The first hole 650 has an area that is a function of the diameter of the channel 645. It is understood that the area of ​​the first hole 650 is empty space and the first hole 650 has no surface. The first face 655 and the first hole 650 form concentric circles that are bisected by the axis of symmetry Q. The first face 655 has a surface that does not include the first hole 650. In other words, the first face 655 has the shape of a flat ring. A second hole 660 is located at the center of a second face 665. The second hole 660 is circular, or generally circular in shape, and opens into the channel 630. The area of ​​the second hole 660 is a function of the diameter of the channel 645. The area of ​​the second hole 660 is understood to be empty space, and the first hole 660 has no surface area. The second face 665 and the second hole 660 form concentric circles bisected by the axis of symmetry Q. The second face 665 has a surface area that does not include the second hole 660. In other words, the second face 665 is shaped like a flat ring. The first face 655 has a first surface area that is the product of the expression (0.25 x π x [ (the diameter of body 640)2- (the diameter of body 645)2]). The second face 665 has a second surface area that is the product of the expression (0.25 xnx [ (the diameter of body 640)2- (the diameter of body 645)2] ). The surface area of ​​the first face 655 is equal to the surface area of ​​the second face 665. Body 620 has a body surface that includes a face surface. The face surface includes the first face 655 and the second face 665. The face surface has a face surface area that is the sum of the surface area of ​​the first face 655 and the surface area of ​​the second face 665. The face surface area is the product of the expression 2 x (0.25 x π x [ (the diameter of body 640)2- (the diameter of body 645)2] ). Figure 8 shows a housing 670. The housing 670 is the outer surface of the body 620 that is parallel to the axis of symmetry Q. The housing 670 has a cylindrical or generally cylindrical shape. The housing 670 includes a housing surface and a housing surface area, the latter of which is the product of the expression (n x the diameter of the body 640 x the length 635). The body 620 has a body surface that includes the housing surface and the face surface. The body surface has a body surface area that is the sum of the housing surface area and the face surface area. In one modality, the body surface area is 25 square millimeters (mm²) or 30 mm² or 32 mm² or 34 mm² or 35 mm² or 40 mm² or 45 mm² or 50 mm². In an additional modality, the body surface area is 25 to 50 mm2 or 30 to 45 mm2 or 35 to 40 mm2. Channel 630 has a channel surface area 675, which includes a channel surface area. The channel surface area is the product of the expression (n x channel diameter 645 x length 635). In one configuration, the channel surface area is 0.5 mm², 1 mm², 2 mm², 3 mm², 6 mm², 7 mm², 8 mm², 9 mm², 10 mm², or 11 mm². In another configuration, the channel surface area is 0.5 to 11 mm², 1 to 9 mm², 1 to 8 mm², or 2 to 8 mm². The 610 pellet has a surface area that is the sum of the body surface area and the channel surface area. In one form, the pellet's surface area is 4 mm², 15 mm², 25 mm², 30 mm², 35 mm² to 40 mm², or 4.5 mm², or 5.0 mm², or 60 mm², or 7.0 mm², or 8.0 mm². In another form, the pellet's surface area is 15 to 80 mm², or 30 to 60 mm², or 35 to 5.0 mm². In one embodiment, (i) the length 635 is from 0.4 mm or 0.8 mm or 1 mm or 1.2 mm or 1.4 mm or 1.5 mm or 1.6 mm or 1.7 mm to 1.9 mm or 2 mm or 2.2 mm or 2.5 mm or 3 mm or 3.3 mm or 3.5 mm or 4 mm; (ii) the body diameter 640 is from 0.7 mm or 0.8 mm or 0.9 mm or 1.0 mm or 1.5 mm to 3.7 mm or 4.0 mm or 4.2 mm or 4.6 mm or 5.0 mm; (iii) the surface area of ​​the pellet is 4 mm2o 15 mm2o 2 5 mm2o 30 mm2o 35 mm2a 4 0 mm2o 4 5 mm2o 50 mm2o 60 mm2o 70 mm2o 80 mm2y (iv) the CBD ratio is 0.03 or 0.05 or 0.07 or 0.11 to 0.13 or 0.15 or 0.2 or 0.25 or 0.3 or 0.35 or 0.4 or 0.45 or 0.5. In a further embodiment, (i) the length 635 is from 0.4 to 4 mm or from 0.8 to 3.5 mm or from 1 to 3.5 mm or from 1.4 to 2.5 mm or from 1.5 to 1.9 mm; (ii) the body diameter 640 is from 0.7 to 5.0 mm or from 0.8 to 4.2 mm or from 1.0 to 4.0 mm; (iii) the surface area of ​​the pellet is 15 to 80 mm2 or 30 to 60 mm2 or 35 to 50 mm2 and (iv) the CBD ratio is 0.03 to 0.5 or 0.05 to 0.45 or 0.05 to 0.25 or 0.05 to 0.15 or 0.11 to 0.15. The 610 pellet has a carcass surface area to body surface area (CSBS) ratio. The term carcass surface area to body surface area (or CSBS) ratio, as used herein, refers to the result obtained by dividing the carcass surface area by the body surface area (i.e., the CSBS is the quotient of carcass surface area by body surface area). For example, when the carcass surface area is 2.0 mm² and the body surface area is 7.0 mm², the CSBS ratio is 0.29. In one modality, the CSBS ratio is 0.02, 0.03, 0.06, 0.10, 0.13, 0.15, 0.18, 0.21, 0.23, 0.25, or 0.3. In another additional modality, the CSBS ratio is 0.02 to 0.3 or 0.03 to 0.25 or 0.03 to 0.23 or 0.03 to 0.21 or 0.03 to 0.18. In one embodiment, (i) the length 635 is 0.4 mm or 0.8 mm or 1 mm or 1.2 mm or 1.4 mm or 1.5 mm or 1.6 mm or 1.7 mm to 1 . 9mm or 2mm or 2.2mm or 2.5mm or 3mm or 3.3mm or 3.5mm or 4mm; (ii) the diameter of the body 640 is 0.7 mm or 0.8 mm or 0.9 mm or 1.0 mm or 1.5 mm to 3.7 mm or 4.0 mm or 4.2 mm or 4.6 mm or 5.0 mm; (iii) the surface area of ​​the pellet is 4 mm2 or 15 mm2 or 2.5 mm2 or 3.0 mm2 or 35 mm2 or 4.0 mm2 or 4.5 mm2 or 50 mm2 or 60 mm2 or 70 mm2 or 80 mm2 and (iv) the CSBS ratio is 0.02 or 0.03 or 0.06 or 0.10 or 0.13 to 0.15 or 0.18 or 0.21 or 0.23 or 0.25 or 0.3. In a further embodiment, (i) the length 635 is from 0.4 to 4 mm or from 0.8 to 3.5 mm or from 1 to 3.5 mm or from 1.4 to 2.5 mm or from 1.5 to 1.9 mm; (ii) the diameter of the 640 body is from 0.7 to 5.0 mm or from 0.8 to 4.2 mm or from 1.0 to 4.0 mm; (iii) the surface area of ​​the pellet is from 15 to 80 mm2 or from 30 to 60 mm2 or from 35 to 50 mm2 and (iv) the CSBS ratio is from 0.02 to 0.3 or from 0.03 to 0.25 or from 0.03 to 0.23 or from 0.03 to 0.21 or from 0.03 to 0.18. The 610 pellet (i.e., hollow pellet) may comprise two or more modalities described in this document. In one embodiment, the retreat distance and extrusion viscosity are selected so that the die assembly 5 produces a fluid-filled pellet 910 having closed ends as shown in Figures 9 and 10. The pellet 910 includes a first closed end 920, a second closed end 930, and a closed channel X. The remaining features of the pellet 910 are identical to the features of the pellet 610, as described herein. The pellet 910 with the first closed end 920 and the second closed end 930 is hereafter referred to interchangeably as the closed pellet. The 910 pellet (i.e., closed pellet) may comprise two or more modalities described in this document. Liquid-filled pellets may comprise two or more modalities described in this document. Extruded Non-limiting examples of a material suitable for use as the extruder include an ethylene-based polymer, a diffin-based polymer (i.e., a polyolefin), an organic polymer, a propylene-based polymer, a thermoplastic polymer, a thermosetting polymer, a molten polymer blend, blends of these polymers, and combinations thereof. Non-limiting examples of suitable ethylene-based polymers include ethylene / alphaolefin interpolymers and ethylene / alphaolefin copolymers. In one embodiment, alphaolefins include, among others, C3-C20 alphaolefins. In a further embodiment, alphaolefins include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene. In one embodiment, the extrudate is an aromatic polyester, a phenol-formaldehyde resin, a polyamide, a polyacrylonitrile, a polyethylene terephthalate, a polyimide, a polystyrene, a polytetrafluoroethylene, a polyvinyl chloride, a thermoplastic polyurethane, a silicone polymer, and combinations thereof. The extrusion may comprise two or more of the modalities described herein. Process This description provides a process for manufacturing fluid-filled pellets 230 (e.g., pellet 610). The process includes providing the die assembly 5, including the die plate 10, which has the inlet surface 15, the discharge surface 35, the discharge port 45, the extrusion step 42, and the third axis of symmetry C. The inlet surface includes the inlet 30 and the first axis of symmetry A, as described herein. The discharge surface 35 includes the discharge port 45 and the second axis of symmetry B, as described herein. The die assembly 5 includes the nozzle 100, which has an injection tip 110, as described herein. The process also includes providing the inlet plate 25 which has the conical inlet port 27 which is aligned with the inlet 30 shown in Figure 1A. The process further includes providing the fluid source 60, the adapter screw 80, and the nozzle 100, wherein the nozzle 100 is mounted on the die plate 10 through the combination of the adapter screw 80, the inlet plate 25, the second locking mechanism, and the third locking mechanism shown in Figure 2. The process further includes providing: (1) an extruder (not shown) that is operatively connected to the die assembly 5; (2) an extrudate; and (3) passing the extrudate through inlet 30 to the extrudate pass 42, as indicated by arrow 5.1 in Figure 5, to provide a uniform distribution of the extrudate along the extrudate pass 42. The process further includes passing the extrudate through the extrudate pass 42 and surrounding the distal end of nozzle 108 and injection tip 110 with the extrudate. The process further includes passing fluid 50 from fluid source 60 through fluid channel 64 and annular channel 70 as indicated by arrows 5.3, 5.4, 5.5, and 5.6 in Figure 5. The extrudate pass and the fluid 50 pass occur simultaneously. The process also includes injecting, with the injection tip 110, the fluid 50 into the extrudate as it exits the discharge port 45 and forming the fluid-filled extrudate 225.In one embodiment, the process includes injecting, with the injection tip 110 in a retracted position O, fluid 50 into the extrudate as it exits the discharge port 45 and forming the fluid-filled extrudate 225. In one embodiment, fluid 50 is injected into the extrudate 210 while the fluid is at a pressure of 100,000 Pa to 520,000 Pa (15 psi to 75 psi). The process further comprises cutting, with the rotary blade apparatus 200, the fluid-filled extrudate 225 emerging from the discharge port 45 and forming fluid-filled pellets 230 (e.g., pellet 610). Figure 4C shows an embodiment in which the process further includes providing the exit plate 300, which includes the exit face 310, the exit port 320, and the exit channel 330. The process further includes passing the extrudate from the extrudate pass 42 to the exit channel 330 and surrounding the injection tip 110 in the retraction position P with the extrudate. The injection tip injects fluid 50 into the extrudate as the extrudate exits the exit port 320 to form a fluid-filled extrudate 225. The process further includes cutting, with the rotary knife apparatus 200, the fluid-filled extrudate 225 emerging from the exit port 320 and forming fluid-filled pellets 230 (e.g., pellet 610). In one modality, the process includes forming fluid-filled pellets that have two open ends, one open end, no open ends (i.e., two closed ends), and combinations of these. In one embodiment, the process includes forming hollow pellets 610, as shown in Figure 6, when the fluid 50 is air and the liquid-filled pellets have two open ends. In one modality, the process involves forming liquid-filled pellets 910, as shown in Figures 9-10, which have two closed ends. The following examples illustrate this description in more detail. Unless otherwise stated, all parts and percentages are by weight. EXAMPLES The raw materials used in the Examples of the invention (IE) are provided in Table 1 below. Table 1 Trade Name Chemical Class and Description Supplier XUS 38658.00 Ethylene / Octene Copolymer Density: 0.904 g / cm3 MI: 30 g / 10 min at 190 °C / 2.16 kg The Dow Chemical Company XUS 38660.00 Ethylene / Octene Copolymer Density: 0.874 g / cm3 MI: 4.8 g / 10 min at 190 °C / 2.16 kg The Dow Chemical Company DXM-447 Low-Density Polyethylene Density: 0.922 g / cm3 MI: 2.4 g / 10 min at 190 °C / 2.16 kg The Dow Chemical Company Comparative Sample 1 (CS-1) and Examples of the Invention 1-8 (IE-1 to IE-8) are produced using XUS 38658.00 as the extrudate and the process conditions listed in Table 2. The extrusion process uses a twin-screw extruder. The extruder is equipped with a Coperion ZSK-26 extruder and a loss-in-weight feeder (model K-Tron KCLQX3). Fluid 50 (e.g., air or N2) is injected into the extrudate using the die assembly 5 described herein, and a Gala underwater rotating blade apparatus forms pellets. The extruder is equipped with twin 26-millimeter (mm) diameter screws and 11 barrel segments, 10 of which are independently controlled with electric heating and water cooling. The length-to-diameter ratio of the extruder is 44:1. A light-intensity screw design is used to minimize shear heating of the molten polymer. Injection tip 110 and nozzle 100 are not used in CS-1 production because nitrogen flow is not applied. In the absence of nitrogen flow and without the use of injection tip 110 and nozzle 100, both ends of the pellets are sealed. Fluid-filled pellets (IE-1 to IE-8) are produced using injection tip 100 and nozzle 110 of die assembly 5 to inject nitrogen gas into the extrudate. IE-1 to IE-6 are produced using a nitrogen flow rate of 10 ml / min and a nitrogen pressure between 34 kPa (5 psig) and 410 kPa (60 psig). IE-7 and IE-8 are produced using a nitrogen flow rate of 50 ml / min and a nitrogen pressure of 69 kPa (10 psig). Table 2 Sample Identification CS-1 IE-1 IE-2 IE-3 IE-4 IE-5 IE-6 IE-7 IE-8 Pellet Feed Rate (kg / h) 11.3 11.3 11.3 11.3 11.3 11.3 11.3 9.07 9.07 N2 Flow Rate (mL / min) 0.0 10.0 10.0 10.0 10.0 10.0 10.0 50.0 50.0 N2 Pressure (kPag) 0.0 34 34 205 205 410 410 69 69 Spindle RPM 200 200 200 200 200 200 200 150 150 Zone #1 (°C) 99 99 99 99 99 99 99 75 75 Zone #2 (°C) 164 164 164 164 164 164 164 147 147 Zone #3 (°C) 179 179 179 179 179 179 179 160 160 Zone #4 (°C) 180 180 180 180 180 180 180 160 160 Zone #5 (°C) 179 179 179 179 179 179 179 160 160 Zone #6 (°C) 179 179 179 179 179 179 179 160 160 Zone #7 (°C) 179 179 179 179 179 179 179 160 160 Zone #8 (°C) 179 179 179 179 179 179 179 160 160 Zone #9 (°C) 179 179 179 179 179 179 179 160 160 Zone #10 (°C) 180 180 180 180 180 180 180 167 167 Torque (%) 40 40 40 40 40 40 40 49 49 Die Pressure (kPag) 4902 4902 4902 4902 4902 4902 4902 6900 6900 Diverter Valve (°C) 180 180 180 180 180 180 180 160 160 Die Temperature (°C) 220 220 220 220 220 220 220 150 150 Water Temperature (°C) 16 16 16 16 16 16 16 4.4 4.4 Pellet End Type Closed Open Open Open Open Open Open Open Open. The dimensions of the pellets formed from the IE-1 to IE-8 process conditions in Table 2 were obtained using optical microscopy. The optical microscopy results for the IE-1 to IE-8 pellets are listed in Table 3. Table 3 Sample ID Channel Diameter (mm) Body Diameter (mm) Pellet Length (mm) Body SA (mm2) Channel SA (mm2) Pellet SA (mm2) CBD CSBS Ratio IE-1 Ratio 0.18 3.33 1.8 36.2 1.02 37.2 0.054 0.03 IE-2 0.37 3.22 1.8 34.3 2.09 36.4 0.11 0.06 IE-3 0.82 3.34 1.8 35.3 4.63 40.0 0.25 0.13 IE-4 0.39 3.51 1.8 38.9 2.20 41.2 0.11 0.06 IE-5 0.63 3.35 1.8 35.9 3.56 39.5 0.19 0.10 IE-6 0.55 3.57 1.8 39.7 3.11 42.8 0.15 0.08 IE-7 0.99 3.56 1.8 38.5 5.60 44.0 0.28 0.15 IE-8 1.52 3.79 1.8 40.4 8.59 48.9 0.40 0.21 CBD is the ratio between the channel diameter and the body diameter. CSBS is the ratio between the channel surface area and the body surface area. SA is surface area. Examples of the invention 9 and 10 (IE-9 and IE-10) listed in Table 4 are produced using the experimental conditions summarized in Table 2, except where otherwise indicated. The extrusion temperature is 200 °C. The pellet channel diameter of IE-9 is approximately 0.90 mm. The pellet formed in IE-10 has an oval shape with a short axis of 0.64 mm and a long axis of 1.27 mm. Table 4 Sample Identification IE-9 IE-10 Polymer Resin XUS38660.00 DXM-447 Pellet Feed Rate (kg / h) 9.07 9.07 N2 Flow Rate (mL / min) 50.0 50.0 N2 Pressure (kPag) 69 69 Screw RPM 200 200 Zone #1 (°C) 99 100 Zone #2 (°C) 159 159 Zone #3 (°C) 200 200 Zone #4 (°C) 199 200 Zone #5 (°C) 199 200 Zone #6 (°C) 199 200 Zone #7 (°C) 199 200 Zone #8 (°C) 199 200 Zone #9 (°C) 200 200 Zone #10 (°C) 202 200 Torque (%) 48 45 Die pressure (kPag) 7577 7729 Diverter valve (°C) 200 200 Die temperature (°C) 210 210 RPM 1400 1200 Water temperature (°C) 8 8 It is specifically intended that the present description not be limited to the forms and illustrations contained herein, but include modified forms of those forms that include parts of the forms and combinations of elements of different forms that are within the scope of the following claims. It is hereby stated that, as of this date, the best method known to the applicant for putting the aforementioned invention into practice is the one that is clear from the present description of the invention.

Claims

Having described the invention as above, the following claims are claimed as property: 1.A die assembly characterized in that it comprises: (i) a die plate having an inlet surface and an opposing discharge surface; (ii) an inlet in the inlet surface and a first axis of symmetry extending through the inlet and perpendicular to the inlet surface; (iii) a discharge port in the discharge surface and a second axis of symmetry extending through the discharge port and perpendicular to the discharge surface, the second axis of symmetry being separate from and parallel to the first axis of symmetry; (iv) an extrusion step seamlessly connecting the inlet and the discharge port, and a third axis of symmetry extending through the extrusion step; (v) a nozzle mounted on the die plate, the nozzle having an injection tip in the extrusion step at the discharge port; and (vi) the third axis of symmetry intersects the first axis of symmetry at the inlet to form an acute angle.

2. The array assembly according to claim 1, characterized in that the third axis of symmetry intersects the second axis of symmetry at the discharge port to form an acute angle.

3. The matrix assembly according to claim 1, characterized in that the nozzle is a stepped nozzle.

4. The matrix assembly according to claim 3, characterized in that the nozzle has a distal end including the injection tip; and a proximal end opposite the injection tip, the proximal end of the nozzle being in fluid communication with a fluid source.

5. The matrix assembly according to claim 4, characterized in that the distal end of the nozzle has a tip inner diameter (TID) and the proximal end of the nozzle has a proximal inner diameter (PID) wherein the PID is greater than the TID.

6. The die assembly according to claim 1, characterized in that the injection tip is located in a recoil position that is 0.05 mm to 0.15 mm upstream of the discharge face.

7. The die assembly according to claim 6, characterized in that the extrusion step surrounds the injection tip in the recoil position.

8. The matrix assembly according to claim 7, characterized in that the TID is from 0.25 mm to 0.35 mm.

9. The die assembly according to claim 8, characterized in that the injection tip has an outer diameter of 0.60 mm to 0.90 mm.

10. The matrix assembly according to claim 1, characterized in that it further comprises an inlet plate attached to an upstream face of the matrix plate, the inlet plate having a conical inlet port, the inlet port being adjacent to the inlet.

11. The matrix assembly of any of claims 1 to 10, characterized in that it comprises a rotating blade apparatus in operational communication with the discharge port of the discharge face.

12. The die assembly according to claim 11, characterized in that it comprises: an extrudate in the extrusion step, the extrudate surrounding the injection tip of the nozzle; the injection tip of the nozzle injecting a fluid into the extrudate as the extrudate exits the discharge port to form a fluid-filled extrudate; and the rotating blade apparatus cuts the fluid-filled extrudate to form fluid-filled pellets.

13. The matrix assembly according to claim 12, characterized in that the fluid-filled pellets have open ends.

14. The matrix assembly according to claim 12, characterized in that the fluid-filled pellets have closed ends.

15. The die assembly according to claim 1, characterized in that it comprises an outlet plate attached to the discharge face of the die plate, the outlet plate having an outlet face and an outlet port located on the outlet face; a channel in the outlet plate, the channel seamlessly connecting the discharge port to the outlet port; and the injection tip of the nozzle extending into the channel, the channel surrounding the injection tip.