Method for pelletizing chalcogenide glass rods to make uniform feedstock for injection molding

Abstract

A system for pelletizing glass is disclosed. The system comprises a glass strand, a guide plate, a roller, a cutting wheel, and a protection feature. The glass strand has an elongate body. The guide plate defines a channel that extends between opposed first and second ends of the guide plate. The channel slidably supports the glass strand for advancement therethrough. The roller has a contact surface configured to continuously engage and advance the glass strand through the channel and out of the second end. The cutting wheel has teeth configured to pass adjacent the channel at the second end and cut the glass strand into pellets when the glass strand is advanced out of the second end. The protection feature is configured to protect the glass strand and the pellets from defects when the glass strand is advanced through the channel and cut into the pellets.

Description

METHOD FOR PELLETIZING CHALCOGENIDE GLASS RODS TO MAKE UNIFORM FEEDSTOCK FOR INJECTION MOLDINGCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 to U.S. Provisional Application No. 63 / 603,797 filed November 29, 2023, and to U.S. Provisional Application No. 63 / 724,647 filed November 25, 2024, the content of each of which is incorporated herein by reference in its entirety.FIELD

[0002] The present disclosure relates to glass injection molding. In particular, the present disclosure relates to processes and equipment for the inj ection molding of chalcogenide glasses.BACKGROUND

[0003] Commercial injection molding of glasses generally involves a pre-reacted glass media encapsulated in a secondary material to enable the material to flow through an injection molding system and mold parts therefrom. Applicant has developed processes and equipment for the injection molding of low-temperature glasses, such as chalcogenide glasses, to produce optics without a secondary encapsulant. Chalcogenide glasses are non-oxide glasses that include one or more of the chalcogen elements (e.g., Group VIA elements, CAS nomenclature) sulfur (S), selenium (Se), and tellurium (Te) and one or more metals and / or semi-metals (e.g., metalloids). Chalcogenide glasses transmit primarily in the infrared (IR) wavelength region of the electromagnetic spectrum. This relatively high IR transmission is an important property that makes chalcogenide glasses useful for various IR applications, such as IR lenses and similar optics for military, hunting, automotive, marine, and medical applications.

[0004] The feedstock used for injection molding of chalcogenide glasses has previously been produced via crushing of boules of glasses similar to As2Se3 into a quasi-uniform feedstock. The glass feedstock can be crushed, for example, to a -8 / +30 mesh. It was discovered that fines generated during the crushing would attach to the larger particles due the electrical properties of the chalcogenide glass. It was believed that the existence of such glass fines would be acceptable in the process since the glass fines would not bum like plastic fines can burn in related polymer injection molding. However, it was further discovered that the glass fines canlead to bubble inclusions and the buildup of crystalline particles in the melt zones of the injection molding system, which were not otherwise removable. The bubble inclusions can lead to reduced IR transmission through glass lenses formed via injection molding when present at a sufficient volume fraction of the lens. High variability in feedstock shape and size as a result of the crushing process can also lead to reduced IR transmission and other defects. The screening of the glass (super) fines from feedstock produced through boule crushing can lead to unacceptable material losses.

[0005] Consequently, it would be advantageous to develop a new feedstock forming device and a process that uses the device to make more uniform feedstock that overcomes the aforementioned issues. It would be further advantageous to provide a glass article, such as a lens, formed via injection molding with reduced bubble inclusions and improved IR transmission.SUMMARY

[0006] According to aspect (1), a system for pelletizing glass is provided. The system comprises: a glass strand having an elongate body; a guide plate defining a channel that extends therethrough between opposed first and second ends of the guide plate, the channel configured to slidably support the glass strand for advancement therethrough; a roller having a contact surface configured to continuously engage the glass strand and advance the glass strand through the channel and out of the second end when the roller is rotated about a first axis; a cutting wheel having teeth configured to pass adjacent the channel at the second end when the cutting wheel is rotated about a second axis; the teeth configured cut the glass strand into pellets when the glass strand is advanced out of the second end; and a protection feature configured to protect the glass strand and the pellets from defects when the glass strand is advanced through the channel and cut into the pellets.

[0007] According to aspect (2), the system of aspect (1) is provided, wherein the protection feature comprises a cutout in the guide plate that is spaced from and proximate to the second end and exposes a portion of the channel, the contact surface of the roller continuously engaging the glass strand within the cutout.

[0008] According to aspect (3), the system of aspect (2) is provided, wherein the contact surface of the roller is configured to brace the glass strand against a support surface of the guide plate that is exposed within the cutout when the glass strand is advanced through the channel.

[0009] According to aspect (4), the system of aspect (2) or aspect (3) is provided, wherein the guide plate comprises (i) a grooved plate that defines top and side surfaces of the channel between the first and second ends and (ii) a bottom plate positioned against the grooved plate so as to define a bottom surface of the channel for a portion of the guide plate between the first end and the cutout.

[0010] According to aspect (5), the system of aspect (4) is provided, wherein the top surface of the channel corresponds to the support surface against which the roller is configured to brace the glass strand.

[0011] According to aspect (6), the system of aspect (4) is provided, wherein the protection feature comprises a narrowing of the channel along a tip portion of the grooved plate proximate the second end.

[0012] According to aspect (7), the system of aspect (6) is provided, wherein the channel along the tip portion opens to a bottom side of the grooved plate, and wherein a bottom pinch plate is positioned against the bottom side of the grooved plate so as to define a bottom surface of the channel along the tip portion.

[0013] According to aspect (8), the system of aspect (7) is provided, wherein one or more of the top surface defined by the grooved plate and the bottom surface defined by the bottom pinch plate form the narrowing of the channel corresponding to the protection feature.

[0014] According to aspect (9), the system of aspect (8) is provided, wherein a top pinch plate is positioned against a top side of the grooved plate along the tip portion, the tip portion of the grooved plate positioned between the top pinch plate and the bottom pinch plate.

[0015] According to aspect (10), the system of any one of aspects (1) to (9) is provided, wherein the protection feature comprises a material of the contact surface of the roller, the material configured to be soft so as to partially envelop the glass strand when the glass strand is advanced through the channel.

[0016] According to aspect (11), the system of any one of aspects (1) to (9) is provided, wherein the protection feature comprises a soft membrane that covers the contact surface, the soft membrane configured to partially envelop the glass strand when the glass strand is advanced through the channel.

[0017] According to aspect (12), the system of any one of the preceding aspects, wherein the glass strand comprises a plurality of glass strands, and wherein the guide plate defines aplurality of channels that extend substantially in parallel therethrough between the first and second ends of the guide plate, each channel configured to slidably support a respective glass strand for advancement therethrough.

[0018] According to aspect (13), the system of any one of the preceding aspects, wherein the glass strand comprises a chalcogenide glass.

[0019] According to aspect (14), a method for pelletizing glass is provided. The method comprises: advancing a glass strand having an elongate body through a channel defined by a guide plate and extending between opposed first and second ends thereof, the channel configured to slidably support the glass strand during the advancing; cutting the glass strand into pellets while advancing the glass strand out of the second end of the guide plate; and protecting, with a protection feature, the glass strand and the pellets from defects during the advancing and the cutting.

[0020] According to aspect (15), the method of aspect (14) is provided, wherein advancing the glass strand comprises engaging the glass strand with a contact surface of a roller configured to rotate about a first axis.

[0021] According to aspect (16), the method of aspect (14) or aspect (15) is provided, wherein cutting the glass strand into pellets comprises rotating a cutting wheel about a second axis and passing teeth of the cutting wheel adjacent the channel at the second end of the guide plate during the advancing.

[0022] According to aspect (17), the method of any one of aspects (14) to (16) is provided, wherein the protection feature comprises a cutout in the guide plate that is spaced from and proximate to the second end and exposes a portion of the channel, the contact surface of the roller continuously engaging the glass strand within the cutout during the advancing and the cutting.

[0023] According to aspect (18), the method of aspect (1 ) is provided, wherein the contact surface of the roller is configured to brace the glass strand against a support surface of the guide plate that is exposed within the cutout during the advancing and the cutting.

[0024] According to aspect (19), the method of aspect (18) is provided, wherein the guide plate comprises (i) a grooved plate that defines top and side surfaces of the channel and (ii) a bottom plate positioned against the grooved plate so as to define a bottom surface of the channel.

[0025] According to aspect (20), the method of aspect (19) is provided, wherein the top surface of the channel corresponds to the support surface against which the roller is configured to brace the glass strand during the advancing and the cutting.

[0026] According to aspect (21), the method of aspect (19) is provided, wherein the protection feature comprises a narrowing of the channel along a tip portion of the grooved plate proximate the second end.

[0027] According to aspect (22), the method of aspect (21 ) i s provided, wherein the channel along the tip portion opens to a bottom side of the grooved plate, and wherein a bottom pinch plate is positioned against the bottom side of the grooved plate so as to define a bottom surface of the channel along the tip portion.

[0028] According to aspect (23), the method of aspect (22) is provided, wherein one or more of the top surface defined by the grooved plate and the bottom surface defined by the bottom pinch plate form the narrowing of the channel corresponding to the protection feature.

[0029] According to aspect (24), the method of aspect (23) is provided, wherein a top pinch plate is positioned against a top side of the grooved plate along the tip portion, the tip portion of the grooved plate positioned between the top pinch plate and the bottom pinch plate.

[0030] According to aspect (25), the method of any one of aspects (15) to (24) is provided, wherein the protection feature comprises a material of the contact surface of the roller, the material configured to be soft so as to partially envelop the glass strand during the advancing and the cutting.

[0031] According to aspect (26), the method of any one of aspects (15) to (24) is provided, wherein the protection feature comprises a soft membrane that covers the contact surface, the soft membrane configured to partially envelop the glass strand during the advancing and the cutting.

[0032] According to aspect (27), the method of any one of aspects (14) to (26) is provided, wherein advancing the glass strand through the channel comprises advancing a plurality of glass strands, respectively, through a plurality of channels extending substantially in parallel through the guide plate between the first and second ends, each channel configured to slidably support a respective glass strand during the advancing and the cutting.

[0033] According to aspect (28), the method of any one of aspects (14) to (27) is provided, wherein the glass strand comprises a chalcogenide glass.

[0034] According to aspect (29), the method of any one of aspects (14) to (28) is provided, wherein the glass strand is advanced and cut with corresponding parameters such that the pellets have a target size distribution, and wherein a material utilization of the method, based on a mass of the glass strand before cutting compared to a mass of the pellets cut from the glass strand that fall within the target size distribution, is greater than 90%.

[0035] According to aspect (30), the method of aspect (29) is provided, wherein the target size distribution corresponds to a mesh combination of -4 / +20 in accordance with the U.S. Standard Sieve Series (ASTM El 1).

[0036] According to aspect (31), the method of aspect (29) is provided, wherein the target size distribution corresponds to a mesh combination of -8 / +18 in accordance with the U.S. Standard Sieve Series (ASTM El 1).

[0037] According to aspect (32), the method of aspect (29) is provided, wherein the target size distribution corresponds to a mesh combination of -8 / +10 in accordance with the U.S. Standard Sieve Series (ASTM El 1).

[0038] According to aspect (33), the method of any one of aspects (14) to (32) is provided, wherein the glass strand has a diameter in a range of from about 1 mm to about 3 mm.

[0039] According to aspect (34), the method of any one of aspects (14) to (32) is provided, wherein the glass strand has a diameter in a range of from about 2 mm to about 2.5 mm.

[0040] According to aspect (35), the method of any one of aspects (14) to (34) is provided, wherein the glass strand is cut to a length in a range of from about 1 mm to about 3 mm to form the pellets.

[0041] According to aspect (36), the method of any one of aspects (14) to (34) is provided, wherein the glass strand is cut to a length in a range of from about 2 mm to about 2.5 mm to form the pellets.

[0042] According to aspect (37), a method for producing a glass article is provided. The method comprises: forming or obtaining a pelletized feedstock using the method of any one of aspects (14) to (36), the pelletized feedstock comprising pellets of chalcogenide glass; and hot- melt processing the pelletized feedstock to produce the glass article.

[0043] According to aspect (38), the method of aspect (37) is provided, wherein the hot- melt processing comprises injection molding, extrusion, transfer molding, profile extraction, or hot embossing.

[0044] According to aspect (39), the method of aspect (37) is provided, wherein the hot- melt processing comprises injection molding.

[0045] According to aspect (40), the method of any one of aspects (37) to (39) is provided, wherein the injection molding introduces (micro-sized) bubbles into the glass article.

[0046] According to aspect (41), the method of any one of aspects (37) to (40) is provided, wherein the chalcogenide glass comprises selenium, arsenic, and a dopant, the dopant selected from the group consisting of gallium, germanium, indium, antimony, tin, or a combination thereof.

[0047] According to aspect (42), a glass article is provided. The glass article comprises: a body having a first volume of chalcogenide glass, the body formed via an injection molding process; and a plurality of bubble inclusions disposed with the first volume, the bubble inclusions having a second volume that is substantially less than the first volume, wherein the body comprises a transmission with a slope in a range of from about 0.02 to about 0.25 over wavelengths from about 3 pm to about 10 pm.

[0048] According to aspect (43), the glass article of aspect (42) is provided, wherein the slope of the transmission is in a range of from about 0.04 to about 0.22 over the wavelengths.

[0049] According to aspect (44), the glass article of aspect (42) or aspect (43) is provided, wherein a volume fraction of the second volume of the bubble inclusions to the first volume of the body is less than or equal to 3.2 x 10'5.

[0050] According to aspect (45), the glass article of any one of aspects (42) to (44) is provided, the bubble inclusions are substantially aligned within the body along a flow of the chalcogenide glass during the injection molding process.

[0051] According to aspect (46), the glass article of any one of aspects (42) to (45) is provided, wherein the first volume of the body is in a range of from about 0.1 cm3to about 10 cm3.BRIEF DESCRIPTION OF THE DRAWINGS

[0052] FIG. l is a schematic representation of a pelletizer system, comprising a guide plate and roller configured to protect glass strands being advanced through channels in the guide plate for pelletizing via a cutting wheel;

[0053] FIG. 2 is an adaption of the schematic representation of FIG. 1, showing a glass strand advanced through the pelletizer system and pelletized by the cutting wheel;

[0054] FIG. 3 is a perspective view of a guide plate according to embodiments of the present disclosure;

[0055] FIG. 4 is a perspective view of another guide plate according to embodiments of the present disclosure;

[0056] FIG. 5 is a cross-sectional view through the guide plate of FIG. 2 taken along line A-A;

[0057] FIG. 6 is a cross-sectional view through the guide plate of FIG. 2 taken along line B-B;

[0058] FIG. 7 is a cross-sectional view through the guide plate of FIG. 2 taken along line C-C;

[0059] FIG. 8 is a flow chart of a method for pelletizing glass according to embodiments of the present disclosure;

[0060] FIGS. 9-12 are digital images of different sizes of pellets that were formed during a pelletizing trial using embodiments of the pelletizer system of FIGS. 1 and 2;

[0061] FIG. 13 is a graph of relative transmission versus wavelength for a glass puck as- molded from crushed feedstock and for a glass puck as-molded from pelletized feedstock obtained via the pelletizer system of FIGS. 1 and 2;

[0062] FIG. 14 shows digital images of a sample glass puck as-molded from the pelletized feedstock; and

[0063] FIGS. 15 and 16 show X-ray Computed Tomography (X-CT) images taken through two different sections of a sample puck as-molded from the pelletized feedstock in accordance with Example 3.DETAILED DESCRIPTION

[0064] For the purposes of promoting an understanding of the principles of the disclosure, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the disclosure is thereby intended. It is further understood that the present disclosure includes anyalterations and modifications to the illustrated embodiments and includes further applications of the principles disclosed herein as would normally occur to one skilled in the art to which this disclosure pertains.

[0065] As used herein, the term “and / or,” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and / or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination.

[0066] In this document, relational terms, such as first and second, top and bottom, and the like, are used solely to distinguish one entity or action from another entity or action, without necessarily requiring or implying any actual such relationship or order between such entities or actions.

[0067] As used herein, the term “about” means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller, as desired, reflecting tolerances, conversion factors, rounding off, measurement error and the like, and other factors known to those of skill in the art. When the term “about” is used in describing a value or an end-point of a range, the disclosure should be understood to include the specific value or end-point referred to. Whether or not a numerical value or end-point of a range in the specification recites “about,” the numerical value or end-point of a range is intended to include two embodiments: one modified by “about,” and one not modified by “about.” It will be further understood that the end-points of each of the ranges are significant both in relation to the other end-point, and independently of the other end-point.

[0068] Concentrations, amounts, and other numerical data may be expressed or presented herein in a range format. It is to be understood that such a range format is used merely for convenience and brevity and thus should be interpreted flexibly to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range was explicitly recited. As an illustration, a numerical range of “about 1 to about 5” should be interpreted to include not only the explicitly recited values of about 1 to about 5, but also to include individual values and sub-ranges within the indicated range. Thus,included in this numerical range are individual values such as 2, 3, and 4, the sub ranges such as from 1-3, from 2-4, from 3-5, etc., as well as 1, 2, 3, 4, and 5 individually. The same principle applies to ranges reciting only one numerical value as a minimum or maximum. Furthermore, such an interpretation should apply regardless of the breadth of the range or the characteristics being described by the range.

[0069] The terms “substantial,” “substantially,” and variations thereof as used herein, unless defined elsewhere in association with specific terms or phrases, are intended to note that a described feature is equal or approximately equal to a value or description. For example, a “substantially planar” surface is intended to denote a surface that is planar or approximately planar. Moreover, “substantially” is intended to denote that two values are equal or approximately equal. In some embodiments, “substantially” may denote values within about 10% of each other, such as within about 5% of each other, or within about 2% of each other.

[0070] Directional terms as used herein — for example up, down, right, left, front, back, top, bottom, above, below, and the like — are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0071] As used herein the terms "the," "a," or "an," mean "at least one," and should not be limited to "only one" unless explicitly indicated to the contrary. Thus, for example, reference to "a component" includes embodiments having two or more such components unless the context clearly indicates otherwise.

[0072] Referring now to FIGS. 1 and 2, a system 10 for pelletizing glass is shown. The system 10 generally comprises a feeding region 100, a cutting region 200, and a collecting region 300. The feeding region 100 is configured to feed strands of glass (e.g., hereinafter “glass strands” 114) towards the cutting region 200 while utilizing one or more protection features to protect the glass strands 114, which are generally brittle, from defects due to the pelletizing. As used herein, “defects” can include unintended fracture, shattering, and / or similar damage of the glass strands 114 that may arise due to non-axial movements, flexure, and vibrations of the glass strands 114 during the pelletizing. The cutting region 200 is configured to cut the glass strands 114 into smaller segments of a controlled / specified length (hereinafter “pellets” or “glass pellets” 214). The collecting region 300 is configured to collect the glass pellets 214 to be used as uniform feedstock for other processes, such as glass injection molding.

[0073] The glass strands 114 can be formed by any process, including online / inline processes or separate offline processes. In an exemplary embodiment, the glass strands 114 areformed form chalcogenide glass using a glass extrusion process. The glass strands 114 can be formed from other glasses in other embodiments. The chalcogenide glass can be synthesized from raw (starting) materials in a batch process via the ampoule melt technique to produce a boule of the chalcogenide glass. An example of synthesis of a chalcogenide glass boule for use in an injection molding process is described in U.S. Patent No. 7,116,888 Bl, filed on April 13, 2005, the disclosure of which is incorporated herein by reference in its entirety. In embodiments, the boule of chalcogenide glass comprises, in atomic percent, 1% Ge, 38.8% As, and 60.2% Se.

[0074] Once formed, the ends of the glass boule are removed, and the glass boule is loaded into an extruder. The extruder is heated to the softening point of the glass (e.g., about 315 °C), and a ram is activated to extrude glass rods at a predetermined rate (e.g., 0.3mm / min) while the speeds of the pulling rolls of the extruder are adjusted to pull the rods and achieve a substantially constant diameter. The speeds of the pulling rolls of the extruder can be adjusted to produce rods of varying diameters. The extruded rods are then annealed according to an annealing schedule (e.g., 175 °C for 3 hours) to form the glass strands 114 for pelletization. As formed, each glass strand 114 has a continuous, elongate body with a target diameter. The glass strands 114 can be formed with any length, such as from about 300 mm to about 925 mm, and any diameter, such as from about 0.5 mm to about 3.5 mm. In an exemplary embodiment, the glass strands 114 are formed with a diameter of about 2.25 mm and a length of about 762 mm (e.g., 2.5 ft).

[0075] Once formed, the glass strands 114 can be loaded into the system 10 for pelletization. The system 10 is now described with reference to FIGS. 1-7. FIGS. 1 and 2 are near-identical schematic representations of the various components of the system 10 depicted with (FIG. 2) and without (FIG. 1) a glass strand 114 advanced therein. As shown in FIGS. 1 and 2, the system 10 comprises a guide plate 118, a roller 122, a cutting wheel 218, and one or more protection features 130 that cooperate to pelletize the glass strands 114. The guide plate 118 is configured to define a channel 134 that extends therethrough between a first end 138 (e.g., an inlet end) and a second end 142 (e.g., an outlet end) opposite the first end 138. The channel 134 is configured to slidably support the glass strand 114 for advancement through the channel 134 and out of the second end 142.

[0076] In embodiments, the guide plate 118 can be configured to define a plurality of channels 134 that extend substantially in parallel through the guide plate 118 between the first and second ends 138, 142 of the guide plate 118. The channels 134 are configured to slidablysupport a plurality of glass strands 114, respectively, advanced therethrough and out of the second end 142 of the guide plate 118. As best shown in FIGS. 5-7, which are cross-sectional views through the guide plate 118 along lines A- A, B-B, and C-C, respectively, in FIG. 2, the channels 134 are substantially aligned along a common plane. In an exemplary embodiments, as shown in FIGS. 3-7, the guide plate 118 defines at least ten channels 134 configured to slidably support ten glass strands 114 to be advanced therethrough and out of the second end 142 of the guide plate 118.

[0077] According to an aspect, the protection feature 130 comprises a cutout 130a in the guide plate 118. As best shown in FIG. 1, the cutout 130a is positioned (e.g., spaced) between the first and second ends 138, 142 at a position proximate to the second end 142 of the guide plate 118. As shown in FIGS. 3 and 4, which are a perspective views of embodiments of the guide plate 118, and the cross-sectional view in FIG. 7, the cutout 130a exposes a portion of the channel(s) 134. The cutout 130a also exposes a support surface 146 (FIGS. 1 and 7) of the guide plate 118.

[0078] Referring again to FIGS. 1-7, the guide plate 118 comprises a grooved (top) plate 150 and a bottom plate 154 positioned against a bottom side of the grooved plate 150. The grooved plate 150 has groove(s) that is / are configured to define top and side surfaces of the channel 134, as best shown in FIGS. 5-7, between the first and second ends 138, 142. The channels 134 open to the bottom side of the grooved plate 150 such that when the bottom plate 154 is positioned against the bottom side of the grooved plate 150, as shown in FIGS. 1-3 and 5, the bottom plate 154 is configured to define a bottom surface of the channel 134 for a portion of the guide plate 118 between the first end 138 and the cutout 130a. While the channels 134 are depicted as having square / rectangular cross-sectional profiles, the channels 134 can have any cross-sectional shape, such as oblong or circular, in other embodiments.

[0079] The grooved plate 150 defines the support surface 146 within the cutout 130a, and the top surface of the channel 134 corresponds to the support surface 146 within the cutout 130a, as best shown in FIGS. 1 and 7. As best shown in FIG. 7, the cutout 130a is configured to expose the channel 134 such that a height of the side surfaces from the top surface of the channel (e.g., support surface 146) is less than the height and / or diameter of the glass strands 114 so that the glass strands 114 protrude beyond the side surfaces of the channel 134 within the cutout 130a. In an exemplary embodiment, the height of the side surfaces from the top surface of the channel (e.g., support surface 146) is about 1 mm such that 1 mm or more of theglass strand 114 protrudes beyond the side surfaces when the glass strand 114 is at least 2 mm in diameter.

[0080] According to an aspect, the protection feature 130 comprises a narrowing 130b (FIG. 1) of the channel 134 along a tip portion of the grooved plate 150 proximate the second end 142 of the guide plate 118. The narrowing 130b of the channel 130 occurs in an advancing direction of the glass strand 114 from the first end 138 towards the second end (e.g., from left to right relative to the view of FIG. 1). As used herein, “narrowing” means that a size of the channel 134 (e.g., a cross-sectional area) becomes smaller in the advancing direction. In embodiments, the size of the channel 134 at the narrowest / smallest portion of the channel remains sufficient to allow the glass strand 114 to be freely advanced therethrough and out of the second end 142. Such narrowing of the channel 134 further supports and stabilizes the glass strand 114 as it is advanced therethrough, which helps protect the glass strand 114 from defects during the pelletizing.

[0081] Referring now to FIGS. 1, 3, 4, and 6, the portion of the channel 134 along the tip portion is configured to open to a bottom side of the grooved plate 150. In embodiments, the guide plate 118 comprises a top pinch plate 158 and a bottom pinch plate 162 that surround the tip portion of the grooved plate 150 at the second end 142. The bottom pinch plate 162 is positioned against the bottom side of the grooved plate 150 so as to define a bottom surface of the channel 134 along the tip portion. In embodiments, one or more of the top surface defined by the grooved plate 150 and the bottom surface defined by the bottom pinch plate 162 form the narrowing 130b of the channel 134 corresponding to the protection feature 130.

[0082] According to an aspect, the various features of the guide plate 118, including the grooved plate 150, the bottom plate 154, the top pinch plate 158, and the bottom pinch plate 162, as well as fasteners used to connect these features, may be formed from metal, such as 1018 steel. The metal material may provide better durability and dimensional control over comparable fixturing formed from other materials, such as plastic.

[0083] Referring now to FIGS. 1, 2, and 7, the roller 122 has a contact surface 166 configured to engage the glass strand 114 and advance the glass strand 114 through the channel 134 and out of the second end 142 when the roller 122 is rotated about a first axis 170 (e.g., in a clockwise direction as indicated by the arrow about the first axis 170). The contact surface 166 of the roller 122 (or the soft membrane described hereinbelow) is configured to continuously engage the glass strand 114 within the cutout 130a. According to an aspect, aspart of the protection feature associated with the cutout 130a, the contact surface 166 is configured to brace the glass strand 114 against the support surface 146 (e.g., defined by the grooved plate 150 of the guide plate 118) that is exposed within the cutout 130a when the glass strand 114 is advanced through the channel 134.

[0084] Referring again to FIG. 1, according to an aspect, the protection feature 130 comprises a material 130c of the contact surface 166 of the roller 122. The material is configured to be soft so as to partially envelop the glass strand 114 when the glass strand is advanced through the channel 134. As used herein, “soft” is characterized relative to the glass of the glass strands 114 being pelletized. Considerations related to the level of “soft” include a material 130c that (i) is non-damaging to the glass strand 114 and does not cause defects, (ii) provides adequate friction to advance the glass strand 114 through the channel 134, and (iii) is suitably durable to provide the system 10 with extended operation without burdensome maintenance and / or frequent component replacement. In embodiments, “soft” may refer to a material having a Shore A hardness in a range of from about 20A to about 40A, or from about 25 A to about 35 A, or about 30 A.

[0085] Referring now to FIGS. 2 and 7, according to an aspect, the protection feature comprises a soft membrane 130d (e.g., indicated by a thick line in FIG. 2) that covers (e.g., surrounds) the contact surface 166. The soft membrane 130d is configured to grip the glass strands 114 for advancement without causing defects, such as fracture. Similar to the soft material 130c of the contact surface 166, the soft membrane 130d is configured to partially envelop the glass strand 114 when the glass strand 114 is advanced through the channel 134. Considerations related to the level of “soft” for the soft membrane 130d include the same considerations discussed with respect to the soft material 130c of the contact surface 166.

[0086] Referring again to FIGS. 1 and 2, the cutting wheel 218 has teeth 222 configured to pass adjacent the channel 134 at the second end 142 when the cutting wheel 218 is rotated about a second axis 226 (e.g., in a counterclockwise direction as indicated by the arrow about the second axis 226. The teeth 222 are configured cut the glass strand 114 into the pellets 214 when the glass strand 114 is advanced out of the second end 142. As best shown in FIG. 2, the pellets 214 after being cut by the cutting wheel 218 fall in the general direction of a chute 314 configured to capture and store the pellets 214.

[0087] The protection features corresponding to the soft material 130c of the contact surface 166 and the soft membrane 130d about the contact surface 166 can cooperate with theprotection feature corresponding to the cutout 130a to protect the glass strands 114 from defects due to the pelletizing. More specifically, the location of the cutout 130a proximate the second end 142 enable the soft materials 130c, 130d of the roller 122 to keep the glass strand 114 braced against the grooved plate 150 for the short linear translation of the glass strand 114 from the cutout 130a to the cutting wheel 218 adjacent the second end 142 of the channel 134. The protection feature corresponding to the narrowing 130b of the channel 134 along the tip portion of the grooved plate 150 can also cooperate with the location of the cutout 130a and the soft materials 130c, 130d of the roller 122 to further stabilize and protect the glass strand 114 from defects during pelletization.

[0088] In embodiments, parameters of the system 10 can be adjusted to achieve a desired size distribution and material utilization of the pellets 214 cut from the glass strands 114, for example, by controlling a (linear) feed speed (e.g., the rotation rate of the roller 122 about the first axis 170), the cutting wheel 218 rotation rate about the second axis 226, and a length of the cut pellets 214. In embodiments, the diameters of the glass strands 114 can be varied along with the aforementioned system parameters to produce pellets of a predetermined length (e.g., a range of from about 2 mm to about 2.25 mm) in order to preferably achieve a narrow size distribution and reduce material waste.

[0089] Referring now to FIG. 8, a flow chart of a method 700 for pelletizing glass is shown. According to an aspect, the method 700 can be performed using a pelletizer system, such as the (pelletizer) system 10 described with reference to FIGS. 1-7. The method 700 generally comprises the steps 704, 708, and 712. In step 704, the method comprises advancing a glass strand 114 having an elongate body through a channel 134 defined by a guide plate 118 and extending between opposed first and second ends 138, 142 thereof. The channel 134 is configured to slidably support the glass strand 114 during the advancing.

[0090] In step 708, the method 700 comprises cutting, with the cutting wheel 218, the glass strand 114 into pellets 214 while advancing, with the roller 122, the glass strand 114 out of the second end 142 of the guide plate 118.

[0091] In step 712, the method 700 comprises protecting, with a protection feature 130, the glass strand 114 and the pellets 214 from defects during the advancing (step 704) and the cutting (step 708). Protecting the glass strands 114 and the pellets 214 from defects due to the pelletizing can include implementing one or more of the protection features 130a, 130b, 130c, 130d described hereinabove with reference to FIGS. 1-7.

[0092] The system and method for pelletizing glass as disclosed herein has numerous advantages, particularly over systems and methods for pelletizing plastics. Glass is generally brittle, whereas plastics can undergo plastic deformation and avoid breakage, and plastic pelletizing systems are simply not equipped for advancing and cutting such brittle material without unintentional fracture, shattering, and / or similar damage during the pelletizing. More specifically, the system and method disclosed herein incorporates protection features to protect the glass strands from such defects during the pelletizing. The various protection features disclosed hereinabove cooperate to support and stabilize the glass strands as they are advanced through the channels of the guide plate and cut with the cutting wheel.

[0093] The system and method for pelletizing glass as disclosed herein allows for better material utilization of glass than crushing boules of glass to usable sizes. As such, the system and method disclosed herein allows for future automation and less material handling to have to occur to achieve the desired sizes and size distributions of material (e.g., uniform feedstock) for injection molding. Moreover, there is additional safety benefits compared to a boule-crush process in that the pelletizing system and method disclosed herein does not produce airborne fines (mesh size ca. <40) or fumes. The system and method disclosed herein allow glass strands to be pelletized to a more uniform and desired size, which allows for improved quality in injection molded parts (e.g., fewer bubble inclusions and higher transmission) and lower operating costs as material utilization improves.

[0094] The system and method for pelletizing glass as disclosed herein allows for the pelletization of chalcogenide glass rods or strands yielding > 90% material utilization. The equipment parameters are controllable to allow for the control of pellet size and uniformity based on desired needs for experimentation or commercial applications. The equipment parameters and various fixture modifications allow for the change of feed rate and amount of material processed at one time to increase or decrease independently of desired pellet length.

[0095] A method for producing a glass article is now described. The method comprises forming or obtaining a pelletized feedstock comprising pellets of chalcogenide glass. In embodiments, the pelletized feedstock is formed or obtained using the method 700 for pelletizing glass described above with reference to FIG. 8. In embodiments, the method 700 for pelletizing glass is used in connection with the system 100 for pelletizing glass described above with reference to FIGS. 1-7. In embodiments, the chalcogenide glass of the pelletized feedstock comprises selenium, arsenic, and a dopant with the dopant selected from the group consisting of gallium, germanium, indium, antimony, tin, or a combination thereof.

[0096] The method (for producing a glass article) further comprises hot-melt processing the pelletized feedstock to produce the glass article. In embodiments, the hot-melt processing comprises injection molding, extrusion, transfer molding, profile extraction, or hot embossing. In embodiments, the hot-melt processing comprises injection molding. In embodiment in which the hot-melt processing comprises injection molding, the injection molding can introduce (micro-sized) gas bubbles into the glass article.

[0097] The glass article produced by the method comprises a transmission with a slope in a range of from about 0.02 %T / pm to about 0.25 %T / pm over target wavelengths from about 3 pm to about 10 pm. In embodiments, the slope of the transmission is in a range of from about 0.04 %T / pm to about 0.22 %T / pm over the target wavelengths. The slope of the transmission being equal to or less than 0.25 %T / pm is indicative of substantially reduced bubble inclusions in the glass article compared to glass articles formed from crushed (non-pelletized) feedstock.

[0098] EXAMPLES

[0099] The various embodiments of the present disclosure can be better understood by reference to the following Examples which are offered by way of illustration. The present disclosure is not limited to the Examples given herein.

[0100] Example 1 — Pelletizing Trial, Target Size Distribution, and Material Utilization

[0101] Pelletizing trials were performed to assess the capabilities of the pelletizer system 10 disclosed herein with respect to (1) producing pelletized feedstock with a target size distribution and (2) maximizing the material utilization of the pelletized feedstock within the target size distribution. The glass strands used for the pelletizing trials had a diameter of about 2.25 mm. For the pelletizing trials discussed herein, the (adjustable) parameters of the pelletizing system 10 were set to achieve target size distributions of -8 / +10 and / or -8 / +20 (e.g., mesh numbers in accordance with the U.S. Standard Sieve Series (ASTM El 1)). The results of two of these pelletizing trials are summarized in Table 1.Table 1. Material Utilization at Target Size Distributions -8 / +10 and -8 / +20

[0102] As shown in Table 1, the pelletized feedstock at both target size distributions achieved at least 90% material utilization calculated based on a mass of the glass strands before cutting compared to a mass of the pellets cut from the glass strand that fall within the target size distribution. FIGS. 9-12 are digital images of the different sizes of pellets that were formed during the pelletizing trials using the pelletizer system 10. FIG. 9 depicts cut pellets sized in accordance with sieve / mesh #8 (e.g., 2.36 mm). FIG. 10 depicts cut pellets sized in accordance with sieve / mesh # 10 (e.g., 2.0 mm). FIG. 11 depicts cut pellets sized in accordance with sieve / mesh # 20 (e.g., 0.85 mm). FIG. 12 depicts cut pellets remaining after sieving.

[0103] An additional pelletizing trial was performed to further detail the material utilization of the pelletized feedstock produced by the pelletizer system 10 at a single target size distribution of -8 / +10. The result of this pelletizing trial is summarized in Table 2.Table 2. Detailed Material Utilization at Target Size Distribution -8 / +10

[0104] As shown in Table 2, the pelletized feedstock at the target size distribution of -8 / +10 achieved at least 90% material utilization calculated based on the mass of the glass strands before cutting (e.g., 372.122 g) compared to a mass of the pellets cut from the glass strand that fall within the target size distribution (e.g., 344.1 g). This mass comparison amounts to 92.47% material utilization.

[0105] Example 2 — Injection Molding Trials and Infrared Transmission

[0106] Injection molding trials were performed using both crush feedstock obtained via conventional means and pelletized feedstock obtained via the pelletizer system 10 disclosed herein to characterize improvements to infrared (IR) transmission as a result of fewer bubble inclusions in the as-molded glass. The target size distribution was -8 / +10 for both the crushed feedstock and the pelletized feedstock. An injection molding system configured for injectionmolding of glass feedstock was used to mold numerous glass pucks from each type of feedstock. The different feedstock types were processed by the injection molding system under identical operating conditions.

[0107] As previously noted, glass fines can lead to bubble inclusions in the as-molded glass. Such bubble inclusions can lead to reduced infrared IR transmission through glass lenses formed via injection molding when present at a sufficient volume fraction of the lens. For example, FIG. 13 shows a graph with plots of relative transmission (a.u.) versus wavelength for a glass puck as-molded from crushed feedstock and for a glass puck as-molded from pelletized feedstock obtained via the pelletizer system 10 disclosed herein. The graph is annotated with magnified images of the as-molded pucks. As shown in FIG. 13, the image of the puck formed from crushed feedstock shows evidence of substantial bubble inclusions whereas the image of the puck formed from the pelletized feedstock has significantly less bubble inclusions. From this comparison, it can be concluded that the bubble inclusions in the puck formed from crushed feedstock directly contributes to scatter loss, reducing the IR transmission across the wavelengths of interest from about 3 pm to about 10 pm. As shown in FIG. 13, increased scatter loss presents as increased slope of the transmission plot over the wavelengths of interest and reduced scatter loss presents as decreased slope of the transmission plot (e.g., approaching zero) over the wavelengths of interest.

[0108] IR transmission was measured for pucks produced from multiple injection molding runs using both crushed feedstock obtained via conventional means and pelletized feedstock obtained via the pelletizer system 10 disclosed herein. The crushed feedstock and the pelletized feedstock had target size distributions of -8 / +10. The slope of IR transmission was calculated over the wavelengths of interest from about 3 pm to about 10 pm to indirectly assess reduction in bubble inclusions as evidenced by decreased slope of the transmission plots. Table 3 below summarizes the IR transmission slope data.Table 3. Transmission Slope (%T / pm) over Wavelengths from 3 pm to 10 pm

[0109] The pucks produced from the crushed feedstock at -8 / +10 had an average IR transmission slope over the wavelengths of interest of about 1.430 %T / pm with minimum and maximum IR transmission slopes of 1.021 and 1.667, respectively. The pucks produced from the pelletized feedstock at -8 / +10 had an average IR transmission slope over the wavelengths of interest of about 0.142 %T / pm with minimum and maximum IR transmission slopes of 0.044 and 0.222, respectively. The average IR transmission slope resulting from the pelletized feedstock was 90% less than the average IR transmission slope resulting from the crushed feedstock, indicating a substantial reduction in bubble inclusions and, correspondingly, a substantial reduction in scatter loss by use of the pelletized feedstock.

[0110] Example 3 — Characterization of Bubble Inclusions from Pelletized Feedstock[OHl] An analysis was performed on a glass puck as-molded from the pelletized feedstock according to Example 2 to characterize the bubble inclusions with respect to distribution and volume fraction. The distribution refers to the spatial distribution of the bubble inclusions within the glass. The volume fraction refers to the approximate glass volume occupied by the bubble inclusions. FIG. 14 shows digital images of a sample glass puck 400 as-molded from the pelletized feedstock. The left image of FIG. 14 shows the puck 400 comprising a convex (top) face 404, a cylindrical side face 408 extending from the convex face 404, and gate / runner structure 412 extending transversely from cylindrical side face 408. The right image of FIG. 14 shows the puck 400 comprising the cylindrical side face 408, the gate / runner structure 412, and a concave (bottom) face 416 that is opposite the convex face 404. The cylindrical side face 408 extends between the convex face 404 and the concave face 416.

[0112] FIGS. 15 and 16 show X-ray Computed Tomography (X-CT) images taken through two different sections of a sample puck as-molded from the pelletized feedstock according to Example 2. The left image in each of FIGS. 15 and 16 depicts the position of the section plane through the sample puck whereas the right image in each of FIGS. 15 and 16 shows the X-CT image taken through the section plane. The sample puck used for the X-CT images had essentially the same configuration as the sample puck shown in FIG. 14. Is should be appreciated that while only two X-CT images are shown, the X-CT scan of the sample puck acquired numerous sectional images through the entire sample puck. This compilation of sectional images allows for visualization and analysis of the bubble inclusions throughout the entire volume of the sample. The volume fraction and the spatial distribution of the bubble inclusions with the sample puck can be quantified using the sectional images.

[0113] Referring now to FIG. 15, the left image shows the X-CT section oriented transverse to the convex face 404 and substantially aligned with the gate / runner structure 412. In the right image of FIG. 15, three bubble inclusions 500 are clearly depicted in the X-CT image. Referring now to FIG. 16, the left image shows the X-CT section oriented transverse to the convex face 404, but the section of FIG. 16 is rotated about 90° compared to the section of FIG. 15 (left image), such that the section of FIG. 16 is orthogonal to the section of FIG. 15. In the right image of FIG. 16, a single bubble inclusion 500 is clearly depicted in the X-CT images.

[0114] Referring now to FIGS. 15 and 16, it has been found that the bubble inclusions 500 were patterned to be in line with the direction of glass injection into the mold cavity that forms the puck. In other words, the bubble inclusions 500 typically fall on a line in coordination with glass flow from the gate / runner structure 412 (e.g., located vertically at the top of the mold cavity) toward the edge of the puck (e.g., proximate the bottom of the mold cavity). This pattern is illustrated by the vertical alignment of the bubble inclusions 500 of FIG. 15 (right image) and the central position of the bubble inclusion of FIG. 16 (left image), which corresponds to the vertical alignment of the bubble inclusions 500 of FIG. 15 (right image). Referring still to FIGS. 15 and 16, the bubble inclusions 500 seem to reside in the upper 70-80% of the thickness 420 (e.g., closer to the convex surface 404 than to the concave surface 416).

[0115] The volume fraction of the bubble inclusions 500 within the sample were estimated based on the X-CT images, such as those shown in FIGS. 15 and 16. From these images a (first) volume of the sample puck 400 was estimated to be approximately 0.47 cm3. From these same images, a (second) volume of the bubble inclusions 500 (e.g., a total estimated volume of allthe bubble inclusions within the sample puck) was estimated to be approximately 1.5 x 10'5cm3. The volume fraction of the (second) volume of the bubble inclusions 500 relative to the (first) volume of the sample puck 400 is (less than) about 3.2 x 10'5. This volume fraction is not believed to reduce or substantially reduce IR transmission as demonstrated in Example 2. Pucks of different sizes (e.g., volumes) can be fabricated by the injection molding methods disclosed herein. In embodiments, the (first) volume of the puck can be in a range of from about 0.1 cm3to about 10 cm3, such as from about 0.1 cm3to about 15 cm3or from about 0.1 cm3to about 20 cm3.

[0116] While the disclosure has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications, and further applications that come within the spirit of the disclosure are desired to be protected.

Claims

CLAIMSWhat is claimed is:

1. A system for pelletizing glass, comprising: a glass strand having an elongate body; a guide plate defining a channel that extends therethrough between opposed first and second ends of the guide plate, the channel configured to slidably support the glass strand for advancement therethrough; a roller having a contact surface configured to engage the glass strand and advance the glass strand through the channel and out of the second end when the roller is rotated about a first axis; a cutting wheel having teeth configured to pass adjacent the channel at the second end when the cutting wheel is rotated about a second axis; the teeth configured cut the glass strand into pellets when the glass strand is advanced out of the second end; and a protection feature configured to protect the glass strand and the pellets from defects when the glass strand is advanced through the channel and cut into the pellets.

2. The system of claim 1, wherein the protection feature comprises a cutout in the guide plate that is spaced from and proximate to the second end and exposes a portion of the channel, the contact surface of the roller continuously engaging the glass strand within the cutout.

3. The system of claim 2, wherein the contact surface of the roller is configured to brace the glass strand against a support surface of the guide plate that is exposed within the cutout when the glass strand is advanced through the channel.

4. The system of claim 2 or claim 3, wherein the guide plate comprises (i) a grooved plate that defines top and side surfaces of the channel between the first and second ends and (ii) a bottom plate positioned against the grooved plate so as to define a bottom surface of the channel for a portion of the guide plate between the first end and the cutout.

5. The system of claim 4, wherein the top surface of the channel corresponds to the support surface against which the roller is configured to brace the glass strand.

6. The system of claim 4, wherein the protection feature comprises a narrowing of the channel along a tip portion of the grooved plate proximate the second end.

7. The system of claim 6, wherein the channel along the tip portion opens to a bottom side of the grooved plate, and wherein a bottom pinch plate is positioned against the bottom side of the grooved plate so as to define a bottom surface of the channel along the tip portion.

8. The system of claim 7, wherein one or more of the top surface defined by the grooved plate and the bottom surface defined by the bottom pinch plate form the narrowing of the channel corresponding to the protection feature.

9. The system of claim 8, wherein a top pinch plate is positioned against a top side of the grooved plate along the tip portion, the tip portion of the grooved plate positioned between the top pinch plate and the bottom pinch plate.

10. The system of any one of claims 1-9, wherein the protection feature comprises a material of the contact surface of the roller, the material configured to be soft so as to partially envelop the glass strand when the glass strand is advanced through the channel.

11. The system of any one of claims 1-9, wherein the protection feature comprises a soft membrane that covers the contact surface, the soft membrane configured to partially envelop the glass strand when the glass strand is advanced through the channel.

12. The system of any one of the preceding claims, wherein the glass strand comprises a plurality of glass strands, and wherein the guide plate defines a plurality of channels that extend substantially in parallel therethrough between the first and second ends of the guide plate, each channel configured to slidably support a respective glass strand for advancement therethrough.

13. The system of any one of the preceding claims, wherein the glass strand comprises a chalcogenide glass.

14. A method for pelletizing glass, comprising: advancing a glass strand having an elongate body through a channel defined by a guide plate and extending between opposed first and second ends thereof, the channel configured to slidably support the glass strand during the advancing; cutting the glass strand into pellets while advancing the glass strand out of the second end of the guide plate; and protecting, with a protection feature, the glass strand and the pellets from defects during the advancing and the cutting.

15. The method of claim 14, wherein advancing the glass strand comprises engaging the glass strand with a contact surface of a roller configured to rotate about a first axis.

16. The method of claim 14 or claim 15, wherein cutting the glass strand into pellets comprises rotating a cutting wheel about a second axis and passing teeth of the cutting wheel adjacent the channel at the second end of the guide plate during the advancing.

17. The method of any one of claim 14-16, wherein the protection feature comprises a cutout in the guide plate that is spaced from and proximate to the second end and exposes a portion of the channel, the contact surface of the roller continuously engaging the glass strand within the cutout during the advancing and the cutting.

18. The method of claim 17, wherein the contact surface of the roller is configured to brace the glass strand against a support surface of the guide plate that is exposed within the cutout during the advancing and the cutting.

19. The method of claim 18, wherein the guide plate comprises (i) a grooved plate that defines top and side surfaces of the channel and (ii) a bottom plate positioned against the grooved plate so as to define a bottom surface of the channel.

20. The method of claim 19, wherein the top surface of the channel corresponds to the support surface against which the roller is configured to brace the glass strand during the advancing and the cutting.

21. The method of claim 19, wherein the protection feature comprises a narrowing of the channel along a tip portion of the grooved plate proximate the second end.

22. The method of claim 21, wherein the channel along the tip portion opens to a bottom side of the grooved plate, and wherein a bottom pinch plate is positioned against the bottom side of the grooved plate so as to define a bottom surface of the channel along the tip portion.

23. The method of claim 22, wherein one or more of the top surface defined by the grooved plate and the bottom surface defined by the bottom pinch plate form the narrowing of the channel corresponding to the protection feature.

24. The method of claim 23, wherein a top pinch plate is positioned against a top side of the grooved plate along the tip portion, the tip portion of the grooved plate positioned between the top pinch plate and the bottom pinch plate.

25. The method of any one of claims 15-24, wherein the protection feature comprises a material of the contact surface of the roller, the material configured to be soft so as to partially envelop the glass strand during the advancing and the cutting.

26. The method of any one of claims 15-24, wherein the protection feature comprises a soft membrane that covers the contact surface, the soft membrane configured to partially envelop the glass strand during the advancing and the cutting.

27. The method of any one of claim 14-26, wherein advancing the glass strand through the channel comprises advancing a plurality of glass strands, respectively, through a plurality of channels extending substantially in parallel through the guide plate between the first and second ends, each channel configured to slidably support a respective glass strand during the advancing and the cutting.

28. The method of any one of claims 14-27, wherein the glass strand comprises a chalcogenide glass.

29. The method of any one of claims 14-28, wherein the glass strand is advanced and cut with corresponding parameters such that the pellets have a target size distribution, and wherein a material utilization of the method, based on a mass of the glass strand before cutting compared to a mass of the pellets cut from the glass strand that fall within the target size distribution, is greater than 90%.

30. The method of claim 29, wherein the target size distribution corresponds to a mesh combination of -4 / +20 in accordance with the U.S. Standard Sieve Series (ASTM El 1).

31. The method of claim 29, wherein the target size distribution corresponds to a mesh combination of -8 / +18 in accordance with the U.S. Standard Sieve Series (ASTM El 1).

32. The method of claim 29, wherein the target size distribution corresponds to a mesh combination of -8 / +10 in accordance with the U.S. Standard Sieve Series (ASTM El 1).

33. The method of any one of claims 14-32, wherein the glass strand has a diameter in a range of from about 1 mm to about 3 mm.

34. The method of any one of claims 14-32, wherein the glass strand has a diameter in a range of from about 2 mm to about 2.5 mm.

35. The method of any one of claims 14-34, wherein the glass strand is cut to a length in a range of from about 1 mm to about 3 mm to form the pellets.

36. The method of any one of claims 14-34, wherein the glass strand is cut to a length in a range of from about 2 mm to about 2.5 mm to form the pellets.

37. A method for producing a glass article, comprising: forming or obtaining a pelletized feedstock using the method of any one of claims 14- 36, the pelletized feedstock comprising pellets of chalcogenide glass; and hot-melt processing the pelletized feedstock to produce the glass article.

38. The method of claim 37, wherein the hot-melt processing comprises injection molding, extrusion, transfer molding, profile extraction, or hot embossing.

39. The method of claim 37, wherein the hot-melt processing comprises injection molding.

40. The method of any one of claims 37-39, wherein the injection molding introduces (micro-sized) bubbles into the glass article.

41. The method of any one of claims 37-40, wherein the chalcogenide glass comprises selenium, arsenic, and a dopant, the dopant selected from the group consisting of gallium, germanium, indium, antimony, tin, or a combination thereof.

42. A glass article, comprising: a body having a first volume of chalcogenide glass, the body formed via an injection molding process; and a plurality of bubble inclusions disposed with the first volume, the bubble inclusions having a second volume that is substantially less than the first volume, wherein the body comprises a transmission with a slope in a range of from about 0.02 %T / pm to about 0.25 %T / pm over wavelengths from about 3 pm to about 10 pm.

43. The glass article of claim 42, wherein the slope of the transmission is in a range of from about 0.04 %T / pm to about 0.22 %T / pm over the wavelengths.

44. The glass article of claim 42 or claim 43, wherein a volume fraction of the second volume of the bubble inclusions to the first volume of the body is less than or equal to 3.2 x 10’5.

45. The glass article of any one of claims 42-44, wherein the bubble inclusions are substantially aligned within the body along a flow of the chalcogenide glass during the injection molding process.

46. The glass article of any one of claims 42-45, wherein the first volume of the body is in a range of from about 0.1 cm3to about 10 cm3.

Images