Patent Publication Number: US-2021169171-A1

Title: System and method for forming a molded component with an insert

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This non-provisional U.S. Patent application claims priority under 35 U.S.C. § 119(e) to Provisional U.S. Patent Application No. 62/943,975, filed on Dec. 5, 2019, the contents of which are incorporated by reference in their entirety. 
    
    
     FIELD 
     The present disclosure relates generally to methods and systems for forming molded components with inserts. 
     BACKGROUND 
     This section provides background information related to the present disclosure, which is not necessarily prior art. 
     Articles of footwear conventionally include an upper and a sole structure. The upper may be formed from any suitable material(s) to receive, secure, and support a foot on the sole structure. Sole structures generally include a layered arrangement extending between a ground surface and the upper. One or more components of the article of footwear, and particularly, the sole structure, may be formed using various molding systems and processes, such as injection molding and compression molding systems. 
     In some instances, the molded components may include a molded material that is initially provided to the molding system in a fluid state and then solidified to form the molded component. Here, it may be desirable to provide the molded component with one or more pre-formed inserts which become bonded to the molded component. For example, inserts configured for attaching periphery components, such as cleats or studs, may be embedded within the molded material of the molded component. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected configurations and are not intended to limit the scope of the present disclosure. 
         FIG. 1  is a bottom perspective view of an article of footwear including a sole structure formed according to the principles of the present disclosure; 
         FIG. 2  is an exploded perspective view of an example of an insert and traction element used in forming the sole structure of  FIG. 1 ; 
         FIG. 3  is a partial environmental view of a system and method according to the principles of the present disclosure, showing the formation of a plugging material into a plurality of blanks; 
         FIG. 4  is a partial environmental view of the system and method of the present disclosure, showing the trimming of the blanks of  FIG. 3 ; 
         FIG. 5  is a partial environmental view of the system and method of the present disclosure, showing the formation of one of the blanks of  FIG. 4  into a plug; 
         FIG. 6A  is a partial environmental view of the system and method of the present disclosure, showing the insertion of one of the plugs of  FIG. 5  into an insert; 
         FIG. 6B  is a cross-sectional view of the insert and plug of  FIG. 6A ; 
         FIG. 7  is a partial environmental view of the system and method of the present disclosure, showing placement of the insert and plug of  FIG. 6A  within a mold; 
         FIG. 8  is a partial environmental view of the system and method of the present disclosure, showing removal of flashing from the insert and plug; 
         FIG. 9  is a partial environmental view of the system and method of the present disclosure, showing attachment of the insert and plug to a substrate; 
         FIG. 10  is a partial environmental view of the system and method of the present disclosure, showing formation of a sole plate including the substrate, insert, and plug of  FIG. 9 ; 
         FIGS. 11A-11C  are cross-sectional views of a mold according to the principles of the present disclosure, showing steps for forming the sole plate of  FIG. 10 ; and 
         FIG. 12  is a partial environmental view of the system and method of the present disclosure, showing removal of the plugging material from the sole plate. 
     
    
    
     Corresponding reference numerals indicate corresponding parts throughout the drawings. 
     DETAILED DESCRIPTION 
     The present disclosure is directed to methods of manufacturing molded articles, systems for use in the methods, molded articles made using the methods and/or the systems, and articles of footwear incorporating the molded articles. In some examples, molded articles are formed with inserts to provide critical elements of the molded articles with more durable or precise features. For example, where molded articles are formed using composite materials, metal or polymeric inserts may be provided within the molded article to provide rigid and durable attachment points for peripheral items, such as detachable traction elements. The methods and systems of the present disclosure are directed towards providing an efficient means for molding the molded articles including the inserts in a single molding process, whereby critical features (e.g., threads) of the inserts are protected during the molding process by a removable plugging material disposed in the critical features of the inserts. Particularly, the critical features of the inserts are temporarily protected during a molding process by the presence of the removable plugging material, whereby once the molding process is completed, the plugging material can be evacuated from the insert to expose the critical features of the insert within the molded article. The use of the systems and methods described herein have been found to improve the quality of molded articles by significantly reducing the level of unwanted molding materials which enter critical features of inserts during the molding process. The use of these systems and methods also improve the speed of production of molded articles, as the removable plugging material can be rapidly evacuated from the insert following molding, and the improved quality of the molded articles results in little if any time being required to clean unwanted molded material from the critical features of the molded articles. 
     In one aspect, the present disclosure is directed to a method for forming a molded article, where the molded article includes an insert having an engagement feature. During molding of the molded article, a plug comprising a plugging material is temporarily disposed in the receptacle, thereby protecting the engagement feature during the molding process by preventing the material forming the molded article from contacting the engagement feature. In one example, the molded article is a sole structure for an article of footwear, such as a sole plate. The method comprises the steps of disposing a plug including a plugging material within a receptacle of an insert, wherein the receptacle includes an engagement feature; placing the insert including the plugging material into a mold; while in the mold, contacting an exterior surface of the insert with a liquid material; solidifying the liquid material in the mold into a solid material, forming a molded article including the insert partially embedded in the solid material, wherein a surface of the insert remains exposed in the molded article; removing the molded article from the mold, and removing the plugging material from the receptacle of the exposed surface of the partially embedded insert, exposing the engagement feature. Optionally, the method can further comprise the step of disposing the plugging material in the insert. Disposing the plugging material can include inserting a pre-shaped (e.g., pre-molded) plug of plugging material into the receptacle of the insert prior to placing the insert into the mold. Alternatively, the plugging material can be disposed into the receptacle of the insert by subjecting the plugging material and the insert to a plug molding operation. In the plug molding operation, the plugging material is molded while in contact with the engagement feature to cover, fill or otherwise protect the engagement feature of the insert. In some cases, this plug molding operation may include softening or melting the plugging material before or while it is disposed within the receptacle of the insert, or solidifying the plugging material while it is disposed within the receptacle of the insert, or both. For example, the step of disposing the plugging material may include curing or partially curing the plugging material, thereby increasing its durometer. In some examples, the receptacle is an aperture formed through the insert and the engagement feature is a female helical thread. Here, a plug of a malleable plugging material may be formed to have a larger diameter than a minor diameter of the female helical threads, such that the plug is pressed into the threads to seal the receptacle. Optionally, during the molding process, a substrate such as a textile can be included in the mold, and can be contacted by the liquid material. When present, the substrate may be attached to the insert. 
     Another aspect of the disclosure provides a system for forming a molded article including an insert. The system includes a plate mold having a plate mold cavity. A carcass is disposed within the plate mold cavity of the plate mold and includes a flexible substrate, an insert attached to the flexible substrate and including a receptacle, and a plugging material disposed within the receptacle of the insert. Here, the plugging material has a durometer of less than 100 Shore 00, and more particularly, ranging from 10 Shore A to 60 Shore A. In some examples, the receptacle includes an aperture formed through at least one end of the insert and including an engagement feature. Here, the engagement feature may include female helical threads. In some examples, the plugging material is formed as a plug disposed within the aperture, flush with the at least one end of the insert. Here, the plug may include an alignment feature configured to be interference fit with a fixture of the plate mold. 
     Example configurations will now be described more fully with reference to the accompanying drawings. Example configurations are provided so that this disclosure will be thorough, and will fully convey the scope of the disclosure to those of ordinary skill in the art. Specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of configurations of the present disclosure. It will be apparent to those of ordinary skill in the art that specific details need not be employed, that example configurations may be embodied in many different forms, and that the specific details and the example configurations should not be construed to limit the scope of the disclosure. 
     The terminology used herein is for the purpose of describing particular exemplary configurations only and is not intended to be limiting. As used herein, the singular articles “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. Additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on,” “engaged to,” “connected to,” “attached to,” or “coupled to” another element or layer, it may be directly on, engaged, connected, attached, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” “directly attached to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     The terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections. These elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example configurations. 
     With reference to  FIGS. 1-11 , a method and system for forming an article of footwear  10  having a sole structure  14  including threaded inserts or bushings  18  is provided. Generally, the method includes pressing a moldable plugging material  102  into a threaded receptacle  22  of the insert  18  to effectively plug the receptacle  22 . The insert  18  is then molded into the sole structure  14  in a separate molding step, where the plugging material  102  disposed within the receptacle  22  prevents molding materials (e.g., liquids) of the sole structure  14  from flowing into the receptacle  22 . After molding of the sole structure  14 , the plugging material  102  can be removed from each of the inserts  18  to expose an interior of the receptacle  22 . By providing the system and method described below, molded components having inserts with critical features (e.g., threads or mating surfaces) can be more easily formed using conventional molding processes, as liquid molding materials provided during the molding process are prevented from pervading the critical features of the insert  18 . 
     With reference to  FIG. 1 , an article of footwear  10  includes an upper  12  and a sole structure  14 . The upper  12  may be a conventional upper  12  including interior surfaces that define an interior void configured to receive and secure a foot for support on the sole structure  14 . The upper  12  may be formed from one or more materials that are stitched or adhesively bonded together to form the interior void. Suitable materials of the upper  12  may include, but are not limited to, a textile including a mesh or a synthetic leather, a foam, and a natural leather. The materials may be selected and located to impart properties of durability, air-permeability, wear-resistance, flexibility, and comfort. 
     The sole structure  14  is attached to the bottom of the upper  12  and defines a ground-engaging surface of the article of footwear  10 . In the illustrated example, the sole structure  14  includes a sole plate  16  having a plurality of inserts  18 . As described in greater detail below, the inserts  18  may be embedded or molded into the sole plate  16  using various methods of molding, such as compression molding or injection molding. As shown, the sole plate  16  and the inserts  18  cooperate to define a ground-engaging surface of the article of footwear  10 . The sole structure  14  may further include one or more traction elements  20  attached to the sole plate  16 . The one or more traction elements  20  may be permanently attached to the sole plate  16 , or may be removably attached to the sole plate  16 . In the illustrated example, the traction elements  20  are formed as removable traction elements  20  that can be selectively attached to and detached from the sole plate  16 . Particularly, the traction elements  20  may be studs  20  configured to interface with the inserts  18  of the sole structure  14 , as described in greater detail below. 
     Referring to  FIG. 2 , examples of an insert  18  and a traction element  20  of the sole structure  14  are shown in greater detail. As shown, the insert  18  includes a receptacle  22  having an aperture extending through at least one end of the insert  18 . In the illustrated example, the aperture of the receptacle  22  extends entirely through a length of the insert  18 . Here, the receptacle  22  is configured to interface with a corresponding component to secure the component to the insert  18 . For instance, in the current example, the receptacle  22  is configured to interface with the traction element  20 . 
     As shown, a first portion of the insert  18  includes a bushing  24  forming the receptacle  22 , and a flange  26  projecting laterally outwardly from a periphery of the bushing  24 . The bushing  24  extends from a first end  28  to a second end  30  along a longitudinal axis A 18  of the insert  18 . A distance from the first end  28  to the second end  30  defines a length L 24  of the bushing  24 , and in this example, the insert  18 . The bushing  24  further includes a peripheral side surface  32  extending between the first end  28  and the second end  30  and defining the outer periphery of the bushing  24 . In the illustrated example, the bushing  24  is formed as a cylinder, such that the peripheral side surface  32  of the bushing  24  has a circular (i.e., constant radius) cross section having a first width W 24 . In other examples, the bushing  24  may have a polygonal or irregular cross section. 
     As illustrated in  FIG. 2 , the receptacle  22  is formed to include an aperture extending through the length L 24  of the bushing  24  from the first end  28  to the second end  30 . Optionally, the aperture of the receptacle  22  may be formed only in one of the first end  28  or the second end  30 , and extend partially through the length L 24  of the bushing  24  such that the receptacle  22  is a blind bore. As provided above, the receptacle  22  is configured to interface with the traction element  20  to secure the traction element  20  to the sole structure  14 . For instance, the receptacle  22  may include first engagement features  25   a  configured to interface with a second engagement feature  25   b  formed on the traction element  20 . In the illustrated example, the receptacle  22  includes first engagement features  25   a  in the form of female helical threads, while the traction element  20  includes corresponding male helical threads  25   b  formed on a shaft  44  of the traction element  20 . In other examples, the first engagement features  25   a  may include detents or keyways configured to interface with corresponding features of the traction element  20 . As shown, a minor diameter of the female helical threads  25   a  of the receptacle  22  define an interior diameter or width W 22  of the receptacle  22 . 
     As provided above, the flange  26  projects laterally outwardly (i.e., perpendicular to the longitudinal axis A 18 ) from the peripheral side surface  32  of the bushing  24  to provide a portion of the insert  18  with a pronounced width W 26 . As shown, the flange  26  includes a top surface  34  and a bottom surface  36  formed on an opposite side of the flange  26  from the top surface  34 . A distance between the top surface  34  and the bottom surface  36  defines a thickness or length L 26  of the flange  26 , which is less than the length L 24  of the bushing  24 . In the illustrated example, each of the top surface  34  and the bottom surface  36  are offset or spaced apart from the ends  28 ,  30  of the bushing  24  along the direction of the longitudinal axis A 18  by a respective distance. In some instances, as shown, each of the surfaces  34 ,  36  may be equally offset from the respective end  28 ,  30  of the bushing  24 . However, in other examples, the surfaces  34 ,  36  may be offset by different distances, or one of the surfaces  34 ,  36  may be flush with the respective end  28 ,  30  of the bushing  24 . A peripheral side surface  38  of the flange  26  extends from the top surface  34  to the bottom surface  36  and defines an outer peripheral profile of the flange  26 . In the illustrated example, the flange  26  is formed as a cylindrical flange, such that the peripheral side surface  38  of the flange  26  has a circular (i.e., constant radius) cross section defining the width W 26 . 
     In some examples, the flange  26  includes one or more attachment features  40 ,  42  configured for securing the insert  18  relative to components of the sole plate  16 . For instance, the illustrated flange  26  includes a series of recesses  40  radially spaced about the circumference of the peripheral side surface  38  and a series of apertures  42  extending through the thickness of the flange  26  from the top surface  34  to the bottom surface  36 . As described in greater detail below, when the sole structure  14  is formed, the materials of the sole plate  16  may interface with the attachment features  40 ,  42  to prevent relative movement between the insert  18  and the components of the sole plate  16 . For example, the recesses  40  are configured to engage a resin or molding material of the sole plate  16  to secure a position of the insert  18  relative to the sole plate  16  when the sole structure  14  is molded. The apertures  42  are configured for receiving a stitching for attaching the insert  18  to a substrate, such as a textile, prior to molding the sole plate  16 . In other examples, the attachment features may be realized as projections extending from any of the surfaces  34 ,  36 ,  38 . 
     Referring still to  FIG. 2 , the traction element  20  generally includes the shaft  44  having the second engagement features  25   b , and a stud or cleat  45  attached to the shaft  44 . As provided above, the shaft  44  including the second engagement features  25   b  is configured to interface with the receptacle  22  including the first engagement features  25   a  to selectively secure the traction element  20  to the sole structure  14 . Accordingly, it is important that the first engagement features  25   a  of the receptacle  22  be free of debris that may impede full engagement between the first engagement features  25   a  and the second engagement features  25   b.    
     Turning now to  FIGS. 3-11 , a method and system  100  for forming the sole structure  14  described above is illustrated. Generally, the system  100  and method provide a means for temporarily plugging the receptacles  22  of the inserts  18  with a material  102  during molding of the sole structure  14  to prevent the materials used in forming the sole plate  16  from contaminating the engagement features  25   a  of the receptacle  22 . After formation of the sole structure  14 , the material  102  can be removed from the receptacles  22  to expose the first engagement features  25   a.    
     With reference to  FIG. 3 , the system  100  is provided with a plugging material  102  operable to be shaped and molded to temporarily plug the receptacle  22  of the insert  18 . The plugging material  102  may include elastomers having a relatively low durometer. For example, materials having a durometer less than 100 Shore 00, and more particularly, materials having a durometer ranging from 10 Shore A to 60 Shore A may be used. The plugging material  102  may include a thermoset material, a thermosettable material (i.e., a material which is initially thermoplastic but becomes thermoset following curing), or a thermoplastic material that has the desired hardness when solidified. In one example, the plugging material  102  is a thermosettable material that can be cured under the application of heat. The plugging material  102  may include natural rubber or synthetic rubber (e.g., gum or green rubbers), such as styrene-butadiene rubber, isoprene rubber, silicone rubber, or combinations thereof. 
     Referring still to  FIG. 3 , a sheet  102   a  of the plugging material  102  is provided to the system  100  in a malleable state, and has a substantially constant thickness T 102a . As shown, the system  100  also includes a die  104  configured for forming the sheet  102   a  into a preform  102   b  having a plurality of blanks  102   c  of the plugging material  102 . Here, the die  104  includes a plurality of die cavities  106  corresponding to a desired shape of the plugging material blanks  102   c . For example, the die cavities  106  of the illustrated example have a rectangular profile for forming rectangular blanks  102   c . In one step, the die  104  is pressed at least partially through the thickness T 102a  of the sheet  102   a  (as indicated by arrow Di) such that the profiles of the die cavities  106  are imparted to the sheet  102   a  to form the preform  102   b  having the plurality of the blanks  102   c.    
     In the illustrated example, the die  104  is pressed only partially through the thickness T 102a  of the sheet  102   a , such that a web area  108  is formed between adjacent ones of the blanks  102   c . The web area  108  has a thickness less than the initial thickness T 102a  of the sheet  102   a  and the blanks  102   c  to provide the preform  102   b  with a series of tear seams along which individual ones of the blanks  102   c  may be removed from the preform  102   b . Optionally, the web area  108  may be perforated to aid in tearing or removal of the blanks  102   c.    
     Referring now to  FIG. 4 , the blanks  102   c  may be trimmed such that the first material  102  is appropriately sized for insertion within the receptacles  22 . Particularly, a volume of each blank  102   c  may be trimmed to be greater than a volume of the receptacle  22 , such that when the plugging material  102  is inserted within the receptacles  22 , the receptacles  22  will be filled with the plugging material  102  to cover the engagement features  25   a , as described in greater detail below. In the illustrated example, the blanks  102   c  are sized by trimming the blanks  102   c  of the preform  102   b  using a cutting tool (e.g., scissors). However, in other examples, the blanks  102   c  may be initially formed at the desired volume by the die  104 , whereby individual ones of the blanks  102   c  can be removed from the preform  102   b  without additional trimming. 
     At  FIG. 5 , the blanks  102   c  of the plugging material  102  are formed into plugs  102   d  configured to be inserted into the receptacles  22  of the inserts  18 . Generally, each of the plugs  102   d  is sized to fill the receptacle  22  such that each of the first engagement features  25   a  is masked or covered by the plugging material  102 . As shown, each plug  102   d  may be formed as a substantially cylindrical body having a length L 102d  and a diameter or width W 102d . Here, the length L 102a  and the width W 102d  of the plug  102   d  are both greater than the length L 24  and the width W 22  of the receptacle  22 , respectively. Particularly, the width W 102d  of the plug  102   d , formed by the outside diameter of the plug  102   d , is greater than the minor diameter of the female helical threads forming the first engagement feature  25   a , such that the plugging material  102  will at least partially extend into the female helical threads when the plug  102   d  is disposed within the receptacle  22 . For example, the width W 102d . (i.e., outside diameter) of the plug  102   d  may be 10% to 25% greater than the width W 22  (i.e., minor diameter) of the receptacle  22  (e.g., 5 mm diameter plug in 4.5 mm diameter receptacle). 
     Optionally, the plug  102   d  may be formed with a first guide hole  110  configured to align the insert  18  during a molding step, as described in greater detail below. In the illustrated example, the first guide hole  110  is an aperture  110  extending along the length L 102d  of the plug  102   d . Here, the aperture  110  is defined as a result of the blank  102   c  being rolled into the shape of the plug  102   d , whereby an inner surface of the blank  102   c  forms the aperture  110 . However, the aperture  110  may be formed by a separate operation, such as by piercing the plug  102   d  using a punch. A size (e.g., diameter) of a cross section of the aperture  110  is selected to provide a slight interference fit between the plug  102   d  and a corresponding feature of an insert mold  112 , as discussed below. 
     While the previous steps provide a method for forming the plugs  102   d  from a sheet  102   a  of the plugging material  102 , in other examples the plugs  102   d  may be formed from other types of material stock. For example, the plugging material  102  may be provided as rod stock already having the desired diameter W 102d  of the plugs  102   d , whereby desired lengths L 102d  of individual ones of the plugs  102   d  can be cut from the rod stock. Accordingly, where the illustrated example of the plug  102   d  shows a seam and the aperture  110  resulting from forming the plug  102   d  from one of the blanks  102   c , in other examples the plug  102   d  may be a solid body corresponding in shape to the receptacle  22 . In such examples, the aperture  110  may be provided along the length of the rod stock or subsequently formed in the plugs  102   d  after being cut into the desired length L 102d . 
     Referring now to  FIGS. 6A and 6B , the plug  102   d  is illustrated as being inserted into the receptacle  22  of the insert  18 . In the illustrated example, the plugging material  102  is provided in a malleable state and can be pressed through the threads  25   a  and into the receptacle  22 . Here, as the plugging material  102  is passed over the threads  25   a , the larger diameter W 102d  of the plug  102   d  will cause the plugging material  102  to conform to the profile of the female threads  25   a , thereby partially filling the threads  25   a , as best shown in  FIG. 6B . As provided above, the length L 102d  and width W 102d  of the plug  102   d  are greater than the length L 24  and width W 22  of the receptacle  22 , such that a portion of the plug  102   d  protrudes from each end  28 ,  30  of the bushing  24 . 
     Referring to  FIG. 7 , the system  100  further includes an insert mold  112  configured for forming and curing the plugging material  102  within the receptacle  22 . For example, with the plug  102   d  inserted in the receptacle  22  of the insert  18 , the insert  18  is positioned within the insert mold  112 . As shown, the insert mold  112  includes a mold cavity  114  having one or more sockets  116  for receiving the inserts  18  and the plugs  102   d . Each socket  116  includes a recess  118  for receiving and aligning a position of the insert  18  within the mold cavity  114 . The recess  118  has a cross-sectional shape corresponding to the profile of the peripheral side surface  32  of the bushing  24 , whereby the bushing  24  can be at least partially inserted within the recess  118  to position the insert  18  and plug  102   d  in the mold cavity  114 . 
     Each socket  116  may include a pin  120  extending from the recess  118  and configured to be inserted at least partially through the plug  102   d  to form a guide hole ( FIG. 8 ) at least partially through the length L 102d  of the plug  102   d . In the illustrated example, the pin  120  has a width W 120  that is greater than a width W 110  of the aperture  110  ( FIG. 6B ), such that when the insert  18  and plug  102   d  are placed at the socket  116 , the pin  120  is press fit within the aperture  110  to secure a position of the insert  18  and plug  102   d . However, in other examples where the plug  102   d  is provided without the aperture  110 , the pin  120  may be configured to pierce the plug  102   d.    
     With the insert  18  and plug  102   d  positioned in the mold cavity  114 , the insert mold  112  is closed and the insert  18  and plug  102   d  are subjected to heat and pressure to mold the plug  102   d  within the receptacle  22 . Optionally, this molding process may fully or partially cure the plugging material  102 . In one example, when the plugging material  102  is a silicone material, the inserts  18  and plugs  102   d  may be pressed for approximately five minutes at a temperature of approximately 170 degrees Celsius in order to mold and at least partially cure the silicone material, increasing its durometer. During the pressing operation, the plugging material  102  is pressed into the female threads  25   a  of the receptacle  22  to fully seal the threads. Further, the size and shape of the pin  120  will be imparted to the cured plug  102   d  such that when the insert  18  is removed from the insert mold  112 , the plug  102   d  will retain the shape of the alignment feature  122  formed at least partially therethrough and having a width W 122  similar to the width W 120  of the pin  120 , as shown in  FIG. 8 . 
     Referring now to  FIG. 8 , during the molding process, excess plugging material  102  may form flashing  102   e  around the bushing  24  of the insert  18 . Accordingly,  FIG. 8  illustrates another step where the flashing  102   e  is separated from the molded plug  102   d , leaving only the molded plug  102   d  and the insert  18 . As shown, once the flashing  102   e  is removed, the molded plug  102   d  is flush with each of the first end  28  and the second end  30  of the bushing  24  such that all of the threads  25   a  of the receptacle  22  are covered by the plugging material  102 . Optionally, when the plugging material  102  is a thermosettable material and has not already been cured in previous steps, once all of the threads  25   a  of the receptacle  22  have been covered by the plugging material  102 , the plugging material  102  can be cured. 
     At  FIG. 9 , one or more of the inserts  18  are attached to a substrate  46  for forming the sole plate  16 . Collectively, the substrate  46 , the attached inserts  18 , and the plugs  102   d  may be referred to as a carcass  47  of the sole plate  16 , which includes the physical components of the sole plate  16  prior to the provision of a molding material  54  (e.g., resin). The substrate  46  may be a fabric or fibrous material configured for use in forming composites. For example, the substrate  46  may be a unidirectional tape or a multi-axial fabric having a series of fibers  48  that are impregnated with resin. The substrate  46  may include at least one of carbon fibers, aramid fibers, boron fibers, glass fibers, and other polymer fibers that form the unidirectional sheet or multi-axial fabric. Fibers  48  such as carbon fibers, aramid fibers, and boron fibers may provide a high Young&#39;s modulus while glass fibers (e.g., fiberglass) and other polymer fibers (e.g., synthetic fibers such as polyamides other than aramid, polyesters, and polyolefins) provide a medium modulus. Additionally or alternatively, the substrate  46  may include a unidirectional tape. Further, the substrate may include multiple sheets, where one or more of the sheets includes fibers formed from the same material or, alternatively, one or more of the sheets includes fibers  48  formed from a different material than the fibers  48  of the other sheets. 
     As shown, the substrate  46  includes one or more openings  50  for receiving a portion of a respective one of the inserts  18 . The openings  50  may be formed in the substrate  46  by a punching or cutting process. In some examples, the openings  50  may be sized for receiving one end  28 ,  30  of the bushing  24  therethrough, such that a surface  34 ,  36  of the flange  26  of the insert  18  faces and abuts a face of the substrate  46  surrounding the opening  50 . Accordingly, a width of each opening  50  may be larger than width W 24  of the bushing  24 , but smaller than the width W 26  of the flange  26 . As shown in  FIG. 9 , the inserts  18  may be attached to the substrate with stitching  52 . For example, the insert  18  may be attached by stitching through the apertures  42  formed in the flange  26 . 
     Referring now to  FIGS. 10-11C , the system  100  may include a plate mold  124  for forming the sole plate  16 . As shown in  FIG. 11A , the plate mold  124  includes a mold cavity  126  defined by an upper mold surface  128  and a lower mold surface  130 . The mold cavity  126  is configured to receive and enclose the carcass  47  therein. One or both of the mold surfaces  128 ,  130  may include contours or features configured to receive the substrate  46  and the inserts  18  and to impart a desired profile to the molded sole plate  16 . 
     As shown, the plate mold  124  may include one or more fixtures  132  positioned within the mold cavity  126 , which are configured to position each of the inserts  18  in a desired arrangement. In the illustrated example, the fixtures  132  are embodied as pins  132  extending from the lower mold surface  130 . Here, the pins  132  are provided as cylindrical bodies having a diameter or width W 132  defined by an outer peripheral sidewall. The width W 132  of the cross section of each pin  132  is selected to be greater than the width W 122  of the cross section of the alignment feature  122  formed in the plug  102   d , such that the pin  132  will provide an interference fit with the alignment feature  122  when the insert  18  and plug  102   d  are pressed onto the pin  132 , as shown in  FIG. 11B . For example, the width W 132  (i.e., outside diameter) of the pin  132  may be 10% to 50% greater than the width W 122  (i.e., diameter) of the alignment feature  122  (e.g., 2 mm diameter pin in 1.5 mm diameter alignment feature). By providing an interference fit between the pins  132  and the plugs  102   d , the positions of the inserts  18  within the mold cavity  126  are maintained during the molding process, thereby providing consistent positioning of the inserts  18  within the finished sole plates  16 . 
     As best shown in  FIG. 11B , when the substrate  46  and the insert  18  are positioned within the plate mold  124  and engaged with the fixtures  132 , at least one of the ends  28 ,  30  of one or more of the inserts  18  may be protected to prevent the molding material  54  from covering the end  28 ,  30 . For example, in the illustrated example, the second ends  30  of each of the inserts  18  are seated against the lower mold surface  130  to form a seal around the second ends  30  of the inserts  18 . Thus, when the molding material  54  is provided to the mold cavity  126 , the second ends  30  of the inserts  18  will be masked by the lower mold surface  130  such that when the molded sole structure  14  is removed from the mold  124  ( FIG. 12 ), the second ends  30  of the inserts  18  will be exposed through the bottom surface of the sole structure  14 . In other examples, the first end  28  of each insert  18  may additionally or alternatively be masked by the upper mold surface  128  during the molding process. 
     Referring to  FIG. 11C , with the substrate  46  and the inserts  18  positioned and secured within the mold cavity  126 , the mold  124  is moved to the closed position to seal the mold cavity  126 , and a molding material  54  is provided to the mold cavity  126 . In some examples, the molding material  54  is a liquid molding material  54  that can be cured by the application of heat and/or pressure. The molding material  54  may include a molten thermoplastic and/or liquid, curable thermoset materials. For example, the molding material  54  may include at least one of an epoxy, a polyurethane, a polymerizable composition, a pre-polymer, or a combination thereof. 
     As the molding material  54  is injected into the mold cavity  126 , the high pressure of the molding material  54  causes the molding material  54  to fill the mold cavity  126  and impregnate the fibers  48  of the substrate  46 . However, by providing the insert  18  with the plug  102   d  in sealing contact with the engagement features  25   a  of the receptacle  22 , the molding material  54  is prevented from flowing into the receptacle  22 . Furthermore, the sealed interface between the pin  132  of the plate mold  124  and the alignment feature  122  prevents the molding material  54  from flowing into the alignment feature  122 . The molding material  54  is then cured in the mold cavity  126  at a predetermined temperature and pressure to form the sole structure  14  including the sole plate  16  and the inserts  18 . 
     Turning now to  FIG. 12 , once the molding material  54  of the sole plate  16  is cured, the sole structure  14  is removed from the mold cavity  126  for a series of finishing steps. As shown, the plugs  102   d  remain within the receptacles  22  after the sole structure  14  is removed from the mold cavity  126 , and must therefore be removed. In the illustrated example, the system  100  may be provided with a punch  134  sized for removing the plugs  102   d  from the receptacles  22 . Particularly, the punch  134  may include a plunger  136  having a width W 136  that is less than the width of the receptacle  22  and greater than the width W 122  of the alignment feature  122 . Thus, the plunger  136  is configured to be pressed against an end of the plug  102   d  and through the receptacle  22  to remove the plug  102   d  from the receptacle  22 . Optionally, the punch  134  may include a protrusion  138  configured to engage the alignment feature  122  of the plug  102   d . For example, the protrusion  138  may have a width W 138  operable to be inserted into the alignment feature  122  to maintain a relative position between the plug  102   d  and the punch  134 . In some examples, the punch  134  may be provided in connection with a mechanical press. However, the punch  134  may be manually operated as well. 
     With the plugs  102   d  removed from the receptacles  22 , the first engagement features  25   a  (i.e., threads) of the receptacles  22  may be cleaned to ensure all of the plugging material  102  is removed from the receptacle  22 . As shown, where the first engagement features  25   a  are formed as helical threads, a tapping step may include running a tap  140  having corresponding male helical threads through the receptacle  22  to remove any remaining fragments of the plugging material  102 . In other examples, where the first engagement features  25   a  are provided as keyways or other attachment geometries, different tools may be used for cleaning the first engagement features  25   a . For example, the first engagement features  25   a  may be cleaned using fluids, such as compressed air or a vacuum. Once the sole structure  14  is finished, it may be attached to the upper  12  of the article of footwear  10  using conventional methods. 
     The system  100  and method provided above provide an efficient means for forming molded components including threaded inserts embedded therein. Particularly, the system  100  and method allow the inserts to be attached to a substrate material of a molded component prior to the molding process, and then accurately placed within the mold in predetermined locations. In addition to providing fixturing for the inserts during the molding process, the aforementioned system  100  and method improve the quality of the molded component by preventing contamination of critical features of the insert during the molding process. Particularly, the molded plugs  102   d  are configured to cover and/or seal the critical features (e.g., threads) such that the critical features can be easily protected. While the present disclosure is provided with respect to the formation of sole structures for articles of footwear, it will be appreciated that the methods discussed herein may apply to formation of other types molded components including any insert having a critical feature that must be unobstructed during use of the component. 
     The following Clauses provide an exemplary configuration for the method, system, sole structure, and article of footwear described above. 
     Clause 1. A method of forming a molded article, the method comprising the steps of: disposing a plug including a first material within a receptacle of an insert, the receptacle including an engagement feature; placing the insert including the first material into a mold; applying a liquid second material to an exterior surface of the insert; solidifying the liquid second material into a solid, forming the molded article including the insert embedded in the solid second material, wherein a surface of the insert is exposed in the molded article; removing the molded article from the mold; and removing the first material from the receptacle of the insert embedded in the molded article to expose the engagement feature. 
     Clause 2. The method of Clause 1, further comprising forming an alignment feature in the plug, the alignment feature configured to engage a corresponding fixture of the mold. 
     Clause 3. The method of Clause 2, wherein forming the alignment feature includes forming the alignment feature to have an interference fit with the fixture. 
     Clause 4. The method of any one of the preceding Clauses, further comprising molding the plug including the first material within the receptacle to cover the engagement feature. 
     Clause 5. The method of Clause 4, wherein molding the plug includes pressing the plug into the receptacle under the effects of heat and pressure. 
     Clause 6. The method of any one of the preceding Clauses, further comprising attaching the insert to a flexible substrate to form a carcass. 
     Clause 7. The method of Clause 6, wherein the flexible substrate includes a plurality of fibers chosen from carbon fibers, aramid fibers, boron fibers, polymer fibers, glass fibers, or any combination thereof. 
     Clause 8. The method of any one of the preceding Clauses, wherein the first material is an elastomer. 
     Clause 9. The method of any one of the preceding Clauses, wherein applying the liquid second material includes an injection molding process. 
     Clause 10. The method of any one of the preceding Clauses, wherein the insert includes a bushing and a flange extending laterally outwardly from the bushing. 
     Clause 11. The method of Clause 10, wherein the receptacle includes an aperture formed at least partially through the bushing. 
     Clause 12. The method of any one of the preceding Clauses, further comprising forming the first material into the plug prior to placing the first material into the insert. 
     Clause 13. The method of Clause 12, wherein the plug has a first width greater than a second width of the receptacle. 
     Clause 14. The method of any one of the preceding Clauses, wherein removing the first material from the receptacle includes pulling the first material from the receptacle. 
     Clause 15. The method of any one of the preceding Clauses, wherein removing the first material from the receptacle includes applying a vacuum to the receptacle. 
     Clause 16. The method of any one of the preceding Clauses, wherein the molded article is a component of an article of footwear. 
     Clause 17. The method of Clause 16, wherein the component of the article of footwear is a sole structure. 
     Clause 18. The method of Clause 17, wherein the sole structure includes a sole plate configured to be ground-engaging. 
     Clause 19. A molded article made by the method according to any of the preceding method Clauses. 
     Clause 20. An article of footwear including the molded article of Clause 19. 
     Clause 21. A system for forming a sole structure for an article of footwear, the system comprising: a plate mold including a plate mold cavity; an insert disposed within the plate mold cavity and including a receptacle; a plug including a first material disposed within the receptacle of the insert, the first material having a durometer less than 100 Shore 00; and a second material disposed within the plate mold cavity and contacting an exterior surface of the insert. 
     Clause 22. The system of Clause 21, wherein the receptacle includes an aperture formed through at least one end of the insert and including an engagement feature. 
     Clause 23. The system of Clause 22, wherein the first material covers the engagement feature and is flush with the at least one end of the insert. 
     Clause 24. The system of Clause 23, wherein the first material is an elastomer. 
     Clause 25. The system of any one of the preceding Clauses, wherein the insert is attached to a substrate by stitching. 
     Clause 26. The system of Clause 25, wherein the second material is disposed within the plate mold cavity and impregnates the substrate. 
     Clause 27. The system of Clause 26, wherein a first diameter of the plug is greater than a second diameter of the receptacle. 
     Clause 28. The system of Clause 27, wherein the plug includes an alignment feature. 
     Clause 29. The system of Clause 28, wherein the plate mold cavity includes a fixture configured to be interference fit with the alignment feature. 
     Clause 30. The system of any one of the preceding Clauses, wherein the first material extends through an entire length of the insert. 
     Clause 31. A molded article made using the system according to any of the preceding system Clauses. 
     Clause 32. An article of footwear including the molded article of Clause 31. 
     The foregoing description has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular configuration are generally not limited to that particular configuration, but, where applicable, are interchangeable and can be used in a selected configuration, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.