Patent Application
20220193956
It is known to soak pellets of polymer resin in liquid additives in order to infuse, or otherwise combine, the additive to the polymeric pellets prior to further processing. In the production plastic coatings for power cables for example, olefin-based polymer pellets are oftentimes soaked in liquid peroxide prior to melt-blending or melt extrusion with other ingredients.
Unfortunately, additive soaking of olefin-based polymer pellets suffers from several drawbacks. Many olefin-based polymer pellets require long soaking times—10 or more hours—in order to incorporate sufficient amount of additive into the pellet. Such long soaking times impart added capital costs for soaking equipment and decrease production throughput rates.
The use of porous pellets is known as a way to reduce the soak time for olefin-based polymer pellets. However, porous olefin-based polymer pellets are expensive to produce, limiting their practical use in industry. Porous olefin-based polymer pellets also exhibit inhomogeneity issues when melt blended or extruded. Consequently, the art recognizes the need for polymeric resin pellets with increased surface area in order to decrease additive soak time without deleteriously impacting downstream production steps.
The art further recognizes the need for equipment that can produce polymeric resin pellets with increased surface area for industrial applications that require an additive soak step for polymeric resin pellets—such as the coating of power cables, for example.
The present disclosure provides a die assembly. In an 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 apart from, and is parallel to, the first axis of symmetry. The die assembly includes (iv) an extrudate passage fluidly connecting the inlet and the discharge port. A third axis of symmetry extends through the extrudate passage. The die assembly includes (v) a nozzle mounted in the die plate, the nozzle having an injection tip in the extrudate passage 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.
For purposes of United States patent practice, the contents of any referenced patent, patent application or publication are incorporated by reference in their entirety (or its equivalent U.S. version is so incorporated by reference), especially with respect to the disclosure of definitions (to the extent not inconsistent with any definitions specifically provided in this disclosure) and general knowledge in the art.
The numerical ranges disclosed herein include all values from, and including, the lower value and the upper value. For ranges containing explicit values (e.g., 1, or 2, or 3 to 5, or 6, or 7) any subrange 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 procedure, whether or not the same is specifically disclosed. In order to avoid any doubt, all compositions claimed through use of the term “comprising” may include any additional additive, adjuvant, or compound, (whether polymerized or otherwise), unless stated to the contrary. In contrast, the term, “consisting essentially of” excludes from the scope of any succeeding recitation any other component, step, or procedure, excepting those that are not essential to operability. The term “consisting of” excludes any component, step, or procedure not specifically delineated or listed. The term “or,” unless stated otherwise, refers to the listed members individually as well as in any combination. Use of the singular includes use of the plural and vice versa.
Unless stated to the contrary, implicit from the context, or customary in the art, all parts and percentages are based on weight and all test methods are current as of the filing date of this disclosure.
“Blend,” “polymer blend” and like terms refer to a combination of two or more polymers. Such a blend may or may not be miscible. Such a combination may or may not be phase separated. Such a combination may or may not contain one or more domain configurations, as determined from transmission electron spectroscopy, light scattering, x-ray scattering, and any other method known in the art.
“Ethylene-based polymer” is a polymer that contains more than 50 weight percent polymerized ethylene monomer (based on the total amount of polymerizable monomers) and, optionally, may contain at least one comonomer. Ethylene-based polymer includes ethylene homopolymer, and ethylene copolymer (meaning units derived from ethylene and one or more comonomers). The terms “ethylene-based polymer” and “polyethylene” may be used interchangeably. Nonlimiting examples of ethylene-based polymer (polyethylene) include low density polyethylene (LDPE) and linear polyethylene. Nonlimiting 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 multi-block copolymers (also known as olefin block copolymer (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). Generally, polyethylene may be produced in gas-phase, fluidized bed reactors, liquid phase slurry process reactors, or liquid phase solution process reactors, using a heterogeneous catalyst system, such as Ziegler-Natta catalyst, a homogeneous catalyst system, comprising Group 4 transition metals and ligand structures such as metallocene, non-metallocene metal-centered, heteroaryl, heterovalent aryloxyether, phosphinimine, and others. Combinations of heterogeneous and/or homogeneous catalysts also may be used in either single reactor or dual reactor configurations. In an embodiment, the ethylene-based polymer does not contain an aromatic comonomer polymerized therein.
“Ethylene plastomers/elastomers” are substantially linear, or linear, ethylene/α-olefin copolymers containing homogeneous short-chain branching distribution comprising units derived from ethylene and units derived from at least one C3-C10α-olefin comonomer, or at least one C4-C8 α-olefin comonomer, or at least one C6-C8 α-olefin comonomer. Ethylene plastomers/elastomers have a density from 0.870 g/cc, or 0.880 g/cc, or 0.890 g/cc to 0.900 g/cc, or 0.902 g/cc, or 0.904 g/cc, or 0.909 g/cc, or 0.910 g/cc, or 0.917 g/cc. Nonlimiting examples of ethylene plastomers/elastomers include AFFINITY™ plastomers and elastomers (available from The Dow Chemical Company), EXACT™ Plastomers (available from ExxonMobil Chemical), Tafmer™ (available from Mitsui), Nexlene™ (available from SK Chemicals Co.), and Lucene™ (available LG Chem Ltd.).
“High density polyethylene” (or “HDPE”) is an ethylene homopolymer or an ethylene/α-olefin copolymer with at least one C4-C10 α-olefin comonomer, or C4-C8 α-olefin comonomer and a density from 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. The HDPE can be a monomodal copolymer or a multimodal copolymer. A “monomodal ethylene copolymer” is an ethylene/C4-C10 α-olefin copolymer that has one distinct peak in a gel permeation chromatography (GPC) showing the molecular weight distribution. A “multimodal ethylene copolymer” is an ethylene/C4-C10 α-olefin copolymer that has at least two distinct peaks in a GPC showing the molecular weight distribution. Multimodal includes copolymer having two peaks (bimodal) as well as copolymer having more than two peaks. Nonlimiting 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; and 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, usually employed to refer to polymers prepared from two different monomers, and polymers prepared from more than two different monomers, e.g., terpolymers, tetrapolymers, etc.
“Low density polyethylene” (or “LDPE”) consists of ethylene homopolymer, or ethylene/α-olefin copolymer comprising at least one C3-C10 α-olefin, preferably C3-C4 that has a density from 0.915 g/cc to 0.940 g/cc and contains long chain branching with broad MWD. LDPE is typically produced by way of high pressure free radical polymerization (tubular reactor or autoclave with free radical initiator). Nonlimiting 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 heterogeneous short-chain branching distribution comprising units derived from ethylene 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 C6-C8 α-olefin comonomer. LLDPE is characterized by little, if any, long chain branching, in contrast to conventional LDPE. LLDPE has a density from 0.910 g/cc, or 0.915 g/cc, or 0.920 g/cc, or 0.925 g/cc to 0.930 g/cc, or 0.935 g/cc, or 0.940 g/cc. Nonlimiting examples of LLDPE include TUFLIN™ linear low density polyethylene resins and DOWLEX™ polyethylene resins, each available from the Dow Chemical Company; and MARLEX™ polyethylene (available from Chevron Phillips).
“Multi-component ethylene-based copolymer” (or “EPE”) comprises units derived from ethylene 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 C6-C8 α-olefin comonomer, such as described in patent references U.S. Pat. Nos. 6,111,023; 5,677,383; and 6,984,695. EPE resins have a density from 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. Nonlimiting 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 that contains more than 50 weight percent polymerized olefin monomer (based on total amount of polymerizable monomers), and optionally, may contain at least one comonomer. Nonlimiting examples of an olefin-based polymer include ethylene-based polymer and propylene-based polymer. An “olefin” and like terms refers to hydrocarbons consisting of hydrogen and carbon whose molecules contain a pair of carbon atoms linked together by a double bond.
A “polymer” is a compound prepared by polymerizing monomers, whether of the same or a different type, that in polymerized form provide the multiple and/or repeating “units” or “mer units” that make up a polymer. The generic term polymer thus embraces the term homopolymer, usually employed to refer to polymers prepared from only one type of monomer, and the term copolymer, usually employed to refer to polymers prepared from at least two types of monomers. It also embraces all forms of copolymer, e.g., random, block, etc. The terms “ethylene/α-olefin polymer” and “propylene/α-olefin polymer” are indicative of copolymer as described above prepared from polymerizing ethylene or propylene respectively and one or more additional, polymerizable α-olefin monomer. It is noted that although a polymer is often referred to as being “made of” one or more specified monomers, “based on” a specified monomer or monomer type, “containing” a specified monomer content, or the like, in this context the term “monomer” is understood to be referring to the polymerized remnant of the specified monomer and not to the unpolymerized species. In general, polymers herein are referred to has 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 homogeneous short-chain branching distribution comprising units derived from ethylene 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 C6-C8 α-olefin comonomer. m-LLDPE has density from 0.913 g/cc, or 0.918 g/cc, or 0.920 g/cc to 0.925 g/cc, or 0.940 g/cc. Nonlimiting 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).
“Ultra low density polyethylene” (or “ULDPE”) and “very low density polyethylene” (or “VLDPE”) each is a linear ethylene/α-olefin copolymer containing heterogeneous short-chain branching distribution comprising units derived from ethylene 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 C6-C8 α-olefin comonomer. ULDPE and VLDPE each has a density from 0.885 g/cc, or 0.90 g/cc to 0.915 g/cc. Nonlimiting examples of ULDPE and VLDPE include ATTANE™ ULDPE resins and FLEXOMER™ VLDPE resins, each available from 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 melted state. The melt blending may be accomplished by one or more of various know processes, e.g., batch mixing, extrusion blending, extrusion molding, and the like. “Melt blended” compositions are compositions which were formed through the process of melt blending.
“Thermoplastic polymer” and like terms refers to a linear or branched polymer that can be repeatedly softened and made flowable when heated and returned to a hard state when cooled to room temperature. A thermoplastic polymer typically has an elastic modulus greater than 68.95 MPa (10,000 psi) as measured in accordance with ASTM D638-72. In addition, a thermoplastic polymer can be molded or extruded into an article of any predetermined shape when heated to the softened state.
“Thermoset polymer”, “thermosetting polymers” and like terms indicate that once cured, the polymer cannot be softened nor further shaped by heat. Thermosetting polymers, once cured, are space network polymers and are highly crosslinked to form rigid three-dimensional molecular structures.
The present disclosure 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 side of the die plate. The inlet surface includes an inlet. A first axis of symmetry, which is perpendicular to the inlet surface, extends through the inlet. The discharge surface includes a discharge port. A second axis of symmetry, which is perpendicular to the discharge surface, extends through the discharge port. The first and second axes of symmetry are spaced apart from one another and are parallel to one another. The die plate includes an extrudate passage that extends from the inlet to the discharge port, (i.e., the extrudate passage fluidly connects the inlet and the discharge port). The die plate includes a third axis of symmetry that extends through the extrudate passage. The die assembly includes a nozzle that is mounted in the die plate. The nozzle has an injection tip. The injection tip of the nozzle is located in the extrudate passage at the discharge port. The third axis of symmetry intersects the first axis of symmetry at the inlet to form an acute angle.
Referring to the drawings and initially to
The terms “upstream” and “downstream” refer to the spatial location of two objects (or components) with respect to each other, whereby “upstream” indicates a position closer to the extrudate source (e.g., the extruder) compared to the term “downstream” referring to a position further away from the extrudate source. Stated differently, with respect to two objects, the first object “upstream” of the second object indicates that the first object is closer to the extrudate source than is the second object, the second object being “downstream” of the first object.
In an embodiment, the die plate 10 is made of one or more metals. Nonlimiting examples of suitable metals include steel, stainless steel, metal composites, and combinations thereof.
In an 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.
In an embodiment, the value of the acute angle D is the same as the value of the acute angle E.
In an embodiment, nozzle 100 is a step nozzle. The term “step nozzle,” as used herein, refers to a nozzle having two or more distinct inner diameters. In an embodiment, nozzle 100 is a step nozzle having three distinct inner diameters. In a further embodiment,
The nozzle proximate end 104 includes a proximate inner diameter K, (or interchangeably referred to as the “PID”) as shown in
In an embodiment, the PID is from 2.2 millimeters (mm), or 2.4 mm, or 2.6 mm, or 2.8 mm, or 3.0 mm to 3.4 mm, or 3.6 mm, or 3.8 mm, or 4.1 mm. In a further embodiment, the PID is from 2.2 to 4.1 mm, or from 2.6 to 3.6 mm, or from 3.0 to 3.4 mm.
In an embodiment, the TID is from 0.22 mm, or 0.25 mm, or 0.28 mm, or 0.30 mm to 0.40 mm, or 0.42 mm, or 0.45 mm, or 0.48 mm. In a further embodiment, the TID is from 0.22 to 0.48 mm, or from 0.24 to 0.40 mm, or from 0.25 to 0.35 mm.
A middle inner diameter L is located at a center portion of the nozzle. In an embodiment, the middle inner diameter L is from 1.0 mm, or 1.2 mm, or 1.4 mm, or 1.6 mm to 1.8 mm, or 2.0 mm, or 2.2 mm, or 2.4 mm. In a further embodiment, the middle inner diameter L is from 1.0 to 2.4 mm, or from 1.2 to 2.2 mm, or from 1.6 to 1.8 mm.
A tip outer diameter N is located at the injection tip 110. In an embodiment, the tip outer diameter N is from 0.45 mm, or 0.50 mm, or 0.55 mm, or 0.60 mm to 0.90 mm, or 0.95 mm, or 1.0 mm, or 1.1 mm. In a further embodiment, the tip outer diameter N is from 0.45 to 1.1 mm, or from 0.50 to 1.0 mm, or from 0.60 to 0.90 mm.
In an embodiment, the exit plate 300 is made of Hardened 01 steel.
The exit plate 300 includes an exit face 310 and an exit port 320 located on the exit face 310. The exit plate 300 includes an exit channel 330, the exit channel 330 fluidly connects the discharge port 45 to the exit port 320. The injection tip 110 extends into the exit channel 330 and the exit channel 330 surrounds the injection tip 110. The injection tip 110 is located at a setback position P that is upstream of the exit face 310 such that the injection tip 110 is not coplanar with the exit face 310. The extrudate passes from extrudate passage 42 into the exit channel 330 and surrounds the injection tip 110 at the setback position P. In an embodiment, the setback position P is from 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 exit face 310. In a further embodiment, the setback position P is from 0.02 mm to 0.22 mm, or from 0.03 mm to 0.18 mm, or from 0.05 mm to 0.15 mm upstream of the exit face 310. The injection tip injects the fluid 50 into the extrudate as the extrudate exits the exit port 320 to form a fluid-filled extrudate 225. The rotating blade apparatus 200 cuts the fluid-filled extrudate 225 emerging from the exit port 320 to form fluid-filled pellets 230.
In an embodiment, the rotating blade apparatus 200 is selected from a swinging blade, a reciprocating blade, a rotating knife blade, a rotating circular knife blade, a wet-cut underwater strand pelletizer, and a die-face cutter.
In an embodiment, the downstream face of the die assembly 5 and the rotating blade apparatus 200 are submerged completely in a process fluid. The process fluid is selected from water, an oil, a heat transfer fluid, a lubricant or a combination thereof.
Nozzle 100 injects fluid 50 into the extrudate to form the fluid-filled extrudate 225 as shown in
In an embodiment, the gas used as fluid 50 is air, an inert gas, (nitrogen or argon, for example), or a combination thereof. 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 an embodiment, the fluid 50 is nitrogen gas. The pressure of the nitrogen gas is from 5 psig, or 10 psig, or 20 psig to 30 psig, or 50 psig, or 200 psig. In a further embodiment, the pressure of the nitrogen gas is from 5 to 200 psig, or from 10 to 50 psig, or from 20 to 30 psig.
In an embodiment, the nitrogen gas has a flow rate from 2 milliliters per min (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 a further embodiment, the nitrogen flow rate is from 2 to 200 ml/min, or from 5 to 100 mL/min, or from 10 to 50 ml/min.
In an embodiment, fluid 50 is a liquid. Non-limiting examples of suitable liquid include a peroxide, a curing coagent, a silane, an antioxidant, a UV stabilizer, a processing aid, a coupling agent and combinations thereof. In an embodiment, the liquid used as fluid 50 is blended in a polymer carrier. In a further embodiment, other components are added to the fluid 50, the other components accelerate solidification of the fluid 50. Non-limiting examples of other components suitable include oligomers, nucleating agents and a combination thereof.
The fluid 50 may comprise two or more embodiments disclosed herein.
In an embodiment, the setback distance of the injection tip 110 influences the amount of round up.
In an embodiment, the setback distance and the extrude viscosity are selected so die assembly 5 produces fluid-filled pellet 610 having open ends as shown in
In an embodiment, the body 620 has a cylindrical shape. The body 620 includes the first open end 615 and the second open end 625, the ends having a circular shape. The first open end 615 and the second open end 625 are located on opposite side 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
Body 620 has a circular, or a generally circular, cross-sectional shape. Body 620 also has a cylindrical, or a generally cylindrical shape. It is understood that the circular, cross-sectional shape of the body 620 can be altered (i.e., squeezed, pressed or packed), due to forces imparted upon the pellet 610 during industrial scale production and/or handling of the pellet while the pellet is still in a melted state. Consequently, the cross-sectional shape of the body 620 may be more elliptical in shape than circular in shape, thus the definition of “generally circular in cross-sectional shape.”
The body 620 and the channel 630 each has a respective diameter—body diameter 640 and channel diameter 645. The term, “diameter,” as used herein, is the greatest length between two points on body/channel surface that extends through the center, through axis of symmetry Q, of the body/channel. In other words, when the pellet 610 has an elliptical shape (as opposed to a circular shape), the diameter is the major axis of the ellipse. In an embodiment, the shape of the body 620 resembles a hockey puck.
The pellet has a channel diameter-to-body diameter (CBD) ratio. The term, “channel diameter-to-body diameter (or “CBD”) ratio”, 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 an embodiment, the CBD ratio is from 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, the CBD ratio is from 0.03 to 0.5, or from 0.05 to 0.45, or from 0.05 to 0.25, or from 0.05 to 0.15, or from 0.11 to 0.15.
In an 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 channel diameter 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 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; and (iii) the channel diameter 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
A second orifice 660 is located in the center of a second face 665. The second orifice 660 is circular in shape, or generally circular in shape, and opens into the channel 630. The second orifice 660 has an area that is a function of the channel diameter 645. It is understood that the area of the second orifice 660 is a void space and the first orifice 660 does not have a surface. The second face 665 and the second orifice 660 form concentric circles that are bisected by the axis of symmetry Q. The second face 665 has a surface that does not include the second orifice 660. In other words, the second face 665 has the shape of a flat ring.
The first face 655 has a “first surface area” that is the product of the expression (0.25×π×[(the body diameter 640)2−(the channel diameter 645)2]). The second face 665 has a “second surface area” that is the product of the expression (0.25×π×[(the body diameter 640)2−(the channel diameter 645)2]). The surface area of the first face 655 is equal to the surface area of the second face 665.
The body 620 has a body surface that includes a “facial surface.” The facial surface includes the first face 655 and the second face 665. The facial surface has a “facial 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 facial surface area is the product of the expression 2×(0.25×π×[(the body diameter 640)2−(the channel diameter 645)2]).
The channel 630 has a channel surface 675 including a “channel surface area.” The channel surface area is the product of the expression (π×the channel diameter 645×the length 635). In an embodiment, the channel surface area is from 0.5 mm2, or 1 mm2, or 2 mm2, or 3 mm2 to 6 mm2, to 7 mm2, or 8 mm2, or 9 mm2, or 10 mm2, or 11 mm2. In a further embodiment, the channel surface area is from 0.5 to 11 mm2, or from 1 to 9 mm2, or from 1 to 8 mm2, or from 2 to 8 mm2.
The pellet 610 has a surface area that is the sum of the body surface area and the channel surface area. In an embodiment, the pellet surface area is from 4 mm2, or 15 mm2, or 25 mm2, or 30 mm2, or 35 mm2 to 40 mm2, or 45 mm2, or 50 mm2, or 60 mm2, or 70 mm2, or 80 mm2. In a further embodiment, the pellet surface area is from 15 to 80 mm, or from 30 to 60 mm2, or from 35 to 50 mm2.
In an 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 pellet surface area is from 4 mm2, or 15 mm2, or 25 mm2, or 30 mm2, or 35 mm2 to 40 mm2, or 45 mm2, or 50 mm2, or 60 mm2, or 70 mm2, or 80 mm2 and (iv) the CBD ratio is from 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 pellet surface area is from 15 to 80 mm2, or from 30 to 60 mm2, or from 35 to 50 mm2 and (iv) the CBD ratio is from 0.03 to 0.5, or from 0.05 to 0.45, or from 0.05 to 0.25, or from 0.05 to 0.15, or from 0.11 to 0.15.
The pellet 610 has a channel surface area-to-body surface area (CSBS) ratio. The term, “channel surface area-to-body surface area (or “CSBS”) ratio”, as used herein, refers to the result obtained by dividing the channel surface area by the body surface area (i.e., the CSBS is the quotient of the channel surface area by the body surface area). For example when the channel surface area is 2.0 mm2 and the body surface area is 7.0 mm2, the CSBS ratio is 0.29. In an embodiment, the CSBS ratio is from 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 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.
In an 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 pellet surface area is from 4 mm2, or 15 mm2, or 25 mm2, or 30 mm2, or 35 mm2 to 40 mm2, or 45 mm2, or 50 mm2, or 60 mm2, or 70 mm2, or 80 mm2 and (iv) the CSBS ratio is from 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 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 pellet surface area 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 pellet 610 (i.e., hollow pellet), may comprise two or more embodiments disclosed herein.
In an embodiment, the setback distance and the extrude viscosity are selected so die assembly 5 produces a fluid-filled pellet 910 having closed ends as shown in
The pellet 910 (i.e., closed pellet), may comprise two or more embodiments disclosed herein.
The fluid-filled pellets may comprise two or more embodiments disclosed herein.
Non-limiting examples of a material suitable for use as the extrudate include an ethylene-based polymer, an olefin-based polymer (i.e., a polyolefin), an organic polymer, a propylene-based polymer, a thermoplastic polymer, a thermoset polymer, a polymer melt-blend, polymer blends thereof and combinations thereof.
Non-limiting examples of suitable ethylene-based polymer include ethylene/alpha-olefin interpolymers and ethylene/alpha-olefin copolymers. In an embodiment, the alpha-olefins include, but are not limited to, C3-C20 alpha-olefins. In a further embodiment, the alpha-olefins include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene and 1-octene.
In an 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 extrudate may comprise two or more embodiments disclosed herein.
The present disclosure provides a process for making the fluid-filled pellets 230, (e.g., pellet 610). The process includes providing the die assembly 5 including the die plate 10 having the inlet surface 15, the discharge surface 35, the discharge port 45, the extrudate passage 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 that has an injection tip 110, as described herein.
The process further includes providing the intake plate 25 having the conically-shaped intake port 27 that is aligned with the inlet 30 shown in
The process further includes providing the fluid source 60, the adapter screw 80 and the nozzle 100 wherein the nozzle 100 is mounted in die plate 10 through the combination of the adapter screw 80, the intake plate 25, the second interlocking mechanism, and the third interlocking mechanism shown in
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 the inlet 30 into extrudate passage 42, as indicated by arrow 5.1 in
In an embodiment, the process includes forming fluid-filled pellets having two open ends, one open end, no open ends (i.e., two closed ends), and combinations thereof.
In an embodiment, the process includes forming hollow pellets 610, as shown in
In an embodiment, the process comprises forming fluid-filled pellets 910, as shown in
The present disclosure is described more fully through the following examples. Unless otherwise noted, all parts and percentages are by weight.
The raw materials used in the Inventive Examples (“IE”) are provided in Table 1 below.
Comparative Sample 1 (CS-1) and Inventive Examples 1-8 (IE-1 to IE-8) are produced with XUS 38658.00 as the extrudate and the process conditions listed in Table 2. The extrusion process uses a Coperion ZSK-26 twin-screw extruder and a loss-in-weight feeder (K-Tron model KCLQX3). The 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 26 millimeter (mm) diameter twin-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 in order to minimize the shear heating of polymer melt.
The injection tip 110 and nozzle 100 are not used in the production of CS-1 because no nitrogen flow is applied. In the absence of nitrogen flow and without the use of the injection tip 110 and nozzle 100 both ends of the pellets are closed.
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 through IE-6 are produced using a nitrogen flow rate of 10 ml/min and a nitrogen pressure between 34 kPag (5 psig) and 410 kPag (60 psig). IE-7 and IE-8 are produced using a nitrogen flow rate of 50 mL/min and a nitrogen pressure of 69 kPag (10 psig).
The dimensions of the pellets formed from process conditions IE-1 to IE-8 from Table 2 are imaged with optical microscopy. The results of the optical microscopy of pellets IE-1 to IE-8 are listed in Table 3.
Inventive Examples 9 and 10 (IE-9 and IE-10) listed in Table 4 are produced using the experimental conditions summarized in Table 2, except for where noted otherwise. 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.
It is specifically intended that the present disclosure not be limited to the embodiments and illustrations contained herein, but include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come with the scope of the following claims.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2019/080380 | 3/29/2019 | WO | 00 |
