Removable helmet cover and manufacturing method

Abstract

To provide a removable helmet cover and a manufacturing method.SOLUTION: Provided is a helmet cover (100) comprising a single integrated shell assembly (202) having a receiving cavity (208), an inner surface (204), and an outer surface (206). The receiving cavity is configured such that an inner surface of the single integrated shell assembly is in contact with an outer surface of a helmet (102). The single integrated shell assembly conformably and removably covers the outer surface of the helmet, the helmet cover.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Patent Application No. 17 / 664,892, filed May 25, 2022, which claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 192,927, filed May 25, 2021, the contents of which are incorporated herein by reference in their entireties.

[0002] (Technical field) The present invention is directed to an injection molded article and method of making the same, the injection molded article being a helmet cover for a protective helmet, and more specifically, a replaceable helmet cover for enhancing the aesthetic appearance of helmets used in the military, construction, manufacturing, and / or competitive sports such as American football, baseball, lacrosse, hockey, horseback riding, skiing, snowboarding, and the like. [Background technology]

[0003] Helmets are standard protective equipment in many athletic, industrial, and military applications. For example, helmets are commonly used in competitive sports such as American football, baseball, lacrosse, hockey, horseback riding, skiing, snowboarding, and as personal protective equipment in construction, manufacturing, and military contexts.

[0004] Each helmet is uniquely shaped to accommodate the user's head size as well as provide protection against the specific crash risks associated with the application. Helmets often include interior cushioning and exterior hardware such as a facemask, chin straps, and trim. In addition, the helmet is designed to meet any safety requirements and regulations associated with the particular application.

[0005] Due to the various design and safety considerations associated with producing and manufacturing helmets, helmets are expensive safety equipment. As a result, players and other users are typically issued only a single helmet for practice, training, or competition. Even when helmets are used in industries and programs with larger budgets, such as professional teams, universities, or the military, the cost of a new helmet limits the number of helmets issued to each user.

[0006] At the same time, users may wish to change the appearance of their uniforms for a variety of reasons, including featuring a "throwback" uniform, supporting a particular cause, honoring a particular person or organization, or celebrating a particular achievement or involvement in a notable athletic event. For these purposes, there are few options available to users who wish to change the look of their helmets. Users can purchase additional helmets, but as explained above, this is not an economical choice and most organizations cannot afford to pursue this option.

[0007] Helmets may also be painted, covered with adhesive labels or patches, or covered with wraps or multi-piece covers. Each option has drawbacks. For example, painting helmets is time-consuming, expensive, and generally requires the availability of trained individuals to achieve a consistent appearance on all helmets. In addition, painting generally cannot be returned to restore helmets to their original color unless they are repainted, which requires additional time and expense. Adhesive logos and stickers do not require a high skill level, but the cost varies with the quality and size of the sticker. In addition, because of the size and contours of the helmet, the size and shape of the sticker is limited to ensure that the sticker can be applied without wrinkles, air holes, or creases, and as a result, it is not possible to change the overall appearance of the helmet using this method. Wraps and other multi-piece covers are difficult to install accurately and have clearly visible seam lines if they are not applied correctly. While some wraps are available as a single piece, they also use adhesives or heating methods for application. Adhesive wraps are difficult to apply because the product can fold and adhere to itself, and heat and tensioning techniques require professional application which is again expensive and time consuming.

[0008] In any of these applications, if the product is not applied with skill and precision, the end result will not be visually pleasing as there may be helmet-to-helmet variations, wrinkles, creases, and improper orientation. Summary of the Invention [Means for solving the problem]

[0009] The present invention is directed to an injection molded article and method of making the same, the injection molded article being a helmet cover for a protective helmet, and more specifically, a replaceable helmet cover for enhancing the aesthetic appearance of helmets used in the military, construction, manufacturing, and / or competitive sports such as American football, baseball, lacrosse, hockey, horseback riding, skiing, snowboarding, and the like.

[0010] The helmet covers according to the present disclosure are formed from a single piece and therefore do not require assembly. Although such helmet covers are formed from a single piece, they still maintain a snug fit that mimics the shape of large, irregular, and curvilinear helmet forms used in athletics, industrial, and military applications. These helmet covers are designed to fit the helmet conformably and therefore can be applied without the use of adjustments or fasteners. Because such helmet covers are formed from a single piece, they can be applied without visible seams, wrinkles, air holes, and / or creases. These helmet covers can be quickly applied and removed without skill and without damaging or altering the surface of the helmet. These helmet covers can be made in a variety of colors and designs and can include stickers of almost any size, shape, and / or color. These helmet covers do not interfere with the function of the helmet and can withstand normal use conditions. The design and manufacture of the helmet covers also allows the helmet covers to be offered at an economical price, thereby increasing the number of times a team can change the design of its helmet cover.

[0011] As described herein, thermoplastics are used to form injection molded articles and are employed in the manufacturing process. For convenience, reference may be made to a specific type of thermoplastic, such as thermoplastic polyurethane ("TPU"), but it should be understood that the present invention includes all suitable thermoplastics as described herein. The present invention provides a helmet cover. The helmet cover includes a unitary shell assembly including a receiving cavity, an inner surface, and an outer surface. The receiving cavity is configured such that the inner surface of the unitary shell assembly is configured to contact the outer surface of the helmet, and the unitary shell assembly is configured to conformably and removably cover the outer surface of the helmet.

[0012] The present invention also provides a method for manufacturing a helmet cover. The method includes providing a polymer injection unit, comprising: (A) (i) a barrel-mounted screw assembly, the barrel-mounted screw assembly including a screw mounted in a barrel; (ii) a processing space, the processing space including a distal end and a proximal end; and (iii) one or more nozzles in fluid communication with the processing space, the one or more nozzles being disposed at the distal end of the processing space. The method for manufacturing a helmet further includes (B) providing an injection mold tool, the injection mold tool including a mold cavity in fluid communication with the one or more nozzles, the injection mold tool being constructed to integrally form a helmet cover. The method for manufacturing a helmet further includes (C) introducing a polymer material into the processing space. The method of manufacturing the helmet further includes (D) melting the polymeric material in the processing space, where the melting is accomplished by using a screw mounted in the barrel to mix the polymeric material, applying a heat source, bringing the polymeric material to a first predetermined temperature, and creating a predetermined back pressure. The method of manufacturing the helmet further includes (E) injecting a volume of the polymeric material into the mold cavity through one or more nozzles, where the volume of the polymeric material is sufficient to fill the mold cavity. The method of manufacturing the helmet further includes (F) cooling the polymeric material in the mold cavity to a second predetermined temperature. The method of manufacturing the helmet further includes (G) extracting the polymeric material in the mold cavity from the injection mold tool to provide a helmet cover.

[0013] The method for manufacturing a helmet cover may optionally further include (B) providing an injection mold tool, where providing the injection mold tool may further include (i) scanning a helmet to obtain a helmet geometry file, (ii) modifying the helmet geometry file to form a helmet cover geometry file, (iii) printing a three-dimensional helmet cover prototype, (iv) adjusting the helmet cover geometry file, and (v) generating the injection mold tool using the helmet cover geometry file. Modifying the helmet geometry file may include one or more of (a) manipulating the size and / or shape of the helmet cover, (b) modifying the structure of the helmet cover, (c) adding one or more gripping members to the helmet cover, and / or (d) adding a plurality of micro-holes to the helmet cover. Additionally, adjusting the helmet cover geometry file may include providing an improved fit of the helmet cover compared to the three-dimensional helmet cover prototype. The present invention provides, for example, the following items. (Item 1) A helmet cover comprising a unitary shell assembly having a receiving cavity, an inner surface, and an outer surface, the receiving cavity configured such that the inner surface of the unitary shell assembly is configured to contact an outer surface of a helmet, the unitary shell assembly fitably and removably covering the outer surface of the helmet. (Item 2) 2. The helmet cover of item 1, wherein the one-piece shell assembly fitably and removably covers an outer surface of the helmet without the use of adjustable fasteners. (Item 3) 2. The helmet cover according to item 1, further comprising a finishing layer, the finishing layer being adhered to an outer surface of the unitary shell assembly. (Item 4) 2. The helmet cover of item 1, wherein the one-piece shell assembly further comprises one or more openings therethrough, the one or more openings corresponding to one or more openings in the helmet. (Item 5) 2. The helmet cover of claim 1, wherein the unitary shell assembly further comprises a gripping member, the gripping member being snap-fitably attached to an outer edge of an outer surface of the protective helmet. (Item 6) 2. The helmet cover of item 1, wherein the unitary shell assembly is made from injection molded thermoplastic polyurethane (TPU) or thermoformed TPU. (Item 7) 2. The helmet cover according to item 1, wherein the unitary shell assembly is made from a material selected from the group consisting of TPU90, TPU95, and mixtures thereof. (Item 8) Item 1, the helmet cover according to item 1, wherein the unitary shell assembly is made of TPU and, optionally, one or more additives selected from the group consisting of color pigments, finishing surface chemicals, utility additives, and mixtures thereof. (Item 9) 2. The helmet cover of claim 1, wherein the inner surface of the unitary shell assembly is provided with a plurality of microperforations. (Item 10) 2. The helmet cover of claim 1, wherein the outer surface of the unitary shell assembly is provided with a plurality of microperforations. (Item 11) 2. The helmet cover of claim 1, wherein the unitary shell assembly comprises a plurality of micro-apertures, each of the plurality of micro-apertures independently having a diameter of about 1 μm±0.5 μm. (Item 12) The unitary shell assembly includes a plurality of microholes, the plurality of microholes having a density of about 3.2e7 microholes / cm 2 Item 2. The helmet cover according to item 1, having a distribution of (Item 13) 2. The helmet cover according to item 1, wherein the unitary shell assembly has a thickness of 0.25 mm to 4 mm. (Item 14) 2. The helmet cover according to item 1, wherein the unitary shell assembly has a thickness of 1±0.1 mm. (Item 15) 1. A method of manufacturing a helmet cover, the method comprising: A. providing a polymer injection unit, said polymer injection unit comprising: (i) a barrel mounted screw assembly, the barrel mounted screw assembly comprising a screw mounted within a barrel; (ii) a processing space, the processing space having a distal end and a proximal end; (iii) one or more nozzles in fluid communication with the processing space, the one or more nozzles being disposed at the distal end of the processing space; and B. providing an injection mold tool, the injection mold tool comprising a mold cavity in fluid communication with the one or more nozzles, the injection mold tool constructed to form the helmet cover in one piece; C. introducing a polymeric material into said processing space; D. melting the polymeric material within the processing space, the melting being accomplished by using the screw mounted within the barrel to mix the polymeric material, applying a heat source to bring the polymeric material to a first predetermined temperature, and creating a predetermined back pressure; E. injecting a volume of the polymeric material through the one or more nozzles into the mold cavity, the volume of the polymeric material being sufficient to fill the mold cavity; and F. cooling the polymeric material within the mold cavity to a second predetermined temperature; G. Extracting the polymeric material in the mold cavity from the injection mold tool to provide the helmet cover. A method comprising: (Item 16) 16. The method of claim 15, wherein the polymeric material is a thermoplastic polyurethane (TPU). (Item 17) 16. The method of claim 15, wherein the polymeric material is selected from the group consisting of at least TPU90, TPU95, or a mixture thereof. (Item 18) Item 16. The method of item 15, wherein the polymeric material is TPU and, optionally, one or more additives, the one or more additives being selected from the group consisting of color pigments, finishing surface chemicals, utility additives, and mixtures thereof. (Item 19) Item 16. The method according to item 15, wherein the helmet cover has a thickness of 1±0.1 mm. (Item 20) Item 16. The method of item 15, wherein the mold cavity is formed to provide micro-holes on the helmet cover. (Item 21) Item 16. The method for manufacturing the helmet cover according to item 15, further comprising providing micro-holes on the helmet cover via a mechanical process or a laser drilling process after extracting the polymer material in the mold cavity from the mold. (Item 22) Item 16. The method according to item 15, wherein the mold cavity is formed to provide micropores on the helmet cover, the micropores having a diameter of about 1 μm±0.5 μm. (Item 23) Item 16. The method according to item 15, wherein the first predetermined temperature is 230±3°C. (Item 24) Item 16. The method of item 15, wherein the predetermined back pressure is 5±1 bar. (Item 25) Item 16. The method of item 15, wherein the second predetermined temperature is 60±2°C. (Item 26) Item 16. The method of item 15, wherein injecting the volume of the polymeric material is accomplished by applying a first progressive pressure gradient, the progressive pressure gradient being between about 70 bar and 15 bar. (Item 27) 16. The method of claim 15, wherein injecting said volume of said polymeric material occurs within 20±5 seconds. (Item 28) 16. The method of claim 15, wherein cooling the polymeric material within the mold cavity occurs within 60±5 seconds. (Item 29) 16. The method of claim 15, wherein the steps of introducing the polymeric material into the treatment space, melting the polymeric material in the treatment space, injecting a volume of the polymeric material into the mold cavity through one or more nozzles, and cooling the polymeric material in the mold cavity occur within 130±20 seconds. (Item 30) 16. The method of claim 15, wherein injecting the volume of the polymeric material through the one or more nozzles into the mold cavity further comprises holding the mold cavity at a holding pressure of 100 bar when the mold cavity is 99% by volume filled. (Item 31) Providing injection formwork tools is Scanning a helmet and obtaining a helmet geometry file; modifying the helmet geometry file to form a helmet cover geometry file; Printing a 3D helmet cover prototype; Adjusting the helmet cover geometry file; generating the injection mold tool using the helmet cover geometry file; Further comprising: Modifying the helmet geometry file includes one or more of: manipulating a size of the helmet cover, manipulating a shape of the helmet cover, modifying a structure of the helmet cover, adding one or more gripping members to the helmet cover, adding a plurality of micro-holes to the helmet cover, or a combination thereof; Item 16. The method of item 15, wherein adjusting the helmet cover geometry file includes providing an improved fit of the helmet cover compared to a three-dimensional helmet cover prototype. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is an illustration of a helmet cover positioned adjacent to a helmet according to one embodiment of the present disclosure.

[0015] [Diagram 2] FIG. 2 depicts a helmet cover according to one embodiment of the present disclosure.

[0016] [Figure 3A]FIG. 3A is a perspective view of the right side of a helmet cover according to one embodiment of the present disclosure.

[0017] [Figure 3B] FIG. 3B is a perspective view of the rear of a helmet cover according to one embodiment of the present disclosure.

[0018] [Figure 3C] FIG. 3C is a perspective view of the top of a helmet cover according to one embodiment of the present disclosure.

[0019] [Figure 3D] FIG. 3D is a perspective view of a front portion of a helmet cover according to one embodiment of the present disclosure.

[0020] [Figure 3E] FIG. 3E is a perspective view of the bottom of a helmet cover according to one embodiment of the present disclosure.

[0021] [Figure 4] FIG. 4 is a close-up view of an exemplary helmet cover with a gripping member according to one embodiment of the present disclosure.

[0022] [Diagram 5] FIG. 5 depicts a helmet cover with a finishing layer according to one embodiment of the present disclosure.

[0023] [Figure 6] FIG. 6 illustrates a method of manufacturing a helmet cover according to one embodiment of the present disclosure.

[0024] [Figure 7] FIG. 7 depicts a polymer injection unit according to one embodiment of the present disclosure.

[0025] [Figure 8] FIG. 8 depicts an injection mold tool according to one embodiment of the present disclosure.

[0026] [Figure 9] FIG. 9 illustrates a method of providing an injection mold tool according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] The present invention may be understood more readily by perusal of the following detailed description of the invention and study of the included examples.

[0028] As used herein, the following terms have the meanings ascribed to them unless specified otherwise.

[0029] As used in this specification and the claims, the terms "comprise," "comprising," "include," "including," and "includes" are intended to specify the presence of stated materials, substances, features, integers, components, or steps, but they do not exclude the presence or addition of one or more other materials, substances, features, integers, components, steps, or combinations thereof.

[0030] The term "about" modifies the subject values ​​such that they are within an acceptable error range as determined by one of ordinary skill in the art, which will depend in part on the limitations of the measurement system.

[0031] The articles "a" and "an" as used herein, unless otherwise indicated, refer to "one or more" or "at least one." That is, the reference of any element or component of an embodiment by the indefinite article "a" or "an" does not exclude the possibility that more than one element or component is present.

[0032] The term "helmet" as used herein refers to a protective head covering for use in any of a variety of applications, including for sports, personal protective equipment (such as in construction or manufacturing), military, or other applications. The term "helmet" is intended to include any helmet type, including, but not limited to, helmets used in American football, baseball, lacrosse, hockey, equestrian, skiing, snowboarding, construction, military applications, and the like. Suitable exemplary helmets currently on the market are provided in Example 1. It should be understood that one skilled in the art would understand that these helmets may be modified by manufacturers over time and that new helmets may come onto the market. Any similar helmets or future helmet models would be included within the meaning of the term.

[0033] The term "helmet cover" as used herein refers to an article for covering a helmet. The helmet cover may be suitable for any helmet type, including, but not limited to, helmets used in American football, baseball, lacrosse, hockey, equestrian, skiing, snowboarding, construction, military applications, etc. The helmet cover may be used for any suitable purpose, including as a decorative and / or protective cover.

[0034] The term "unitary shell assembly" as used herein refers to any number of components formed in one piece during a manufacturing process. As one non-limiting example, in an embodiment, a unitary shell assembly includes a receiving cavity, an inner surface, and an outer surface, all of which may be formed from the same thermoplastic, a mixture of thermoplastics, or a mixture of a thermoplastic and one or more additives. As another non-limiting example, in an embodiment, a unitary shell assembly includes a receiving cavity, an inner surface, and an outer surface, all of which may be formed within a single mold cavity.

[0035] The term "receiving cavity" as used herein refers to a space configured to receive an object with a predetermined geometric shape. As an example, in an embodiment, a receiving cavity may be configured to receive a helmet of any suitable shape and / or size.

[0036] The term "interior surface" as used herein refers to a surface that faces inwardly towards a user.

[0037] The term "exterior surface" as used herein refers to a surface that faces outwardly toward a user and includes any surface that is not an interior surface. An exterior surface may have one or more outer edges that define the outer limits of the exterior surface.

[0038] The terms "fitted" or "fittably" as used herein refer to a snug, close, or comfortable relationship between two objects. In certain embodiments, a "fitted" relationship allows the two objects to remain in contact in the absence of pulling forces, with or without the aid of fasteners or gripping members.

[0039] The terms "detach" or "detachably" as used herein refer to the ability to separate two objects. In certain embodiments, the objects may be detached through the use of a pulling force.

[0040] The term "adjustable fastener" as used herein refers to a device for closing or securing an object that can be modified or moved to achieve a desired fit or appearance. Exemplary adjustable fasteners can include, but are not limited to, buckles, straps, screws, clamps, hinges, latches, hooks, and clips.

[0041] The term "finish layer" as used herein refers to a surface layer applied to the inner or outer surface of a helmet cover. In certain embodiments, the finish layer may include paint, powder coating, graphics, thin film formulations, or combinations thereof. In certain embodiments, the finish layer may be applied by painting, bead blasting, etching, UV curing, silk screening, hydrodipping, physical vapor deposition, or combinations thereof.

[0042] The terms "adhere," "adheres," or "adhered" as used herein refer to the joining or creating contact between two or more surfaces or materials through molecular interactions.

[0043] The term "gripping member" as used herein refers to a component used to grip or hold the outer edge of the exterior surface.

[0044] The term "snappably attaches" as used herein refers to the closing or fitting of components into place without adjustment via a sudden force.

[0045] The term "thermoplastic" as used herein refers to a class of polymers that become pliable or moldable at certain elevated temperatures and become solid upon cooling. Exemplary thermoplastics include, but are not limited to, polyurethane ("TPU"), polypropylene ("PP"), polyethylene ("PE"), polystyrene ("PS"), polyvinyl chloride ("PVC"), poly(methyl methacrylate) ("PMMA"), polycarbonate ("PC"), polyoxymethylene ("POM"), polyethylene vinyl acetate ("PEVA"), high density polyethylene ("HDPE"), acrylonitrile butadiene styrene ("ABS"), polyamide ("PA nylon"), or mixtures thereof. Different thermoplastics or mixtures of thermoplastics can be used depending on the application, including the desired physical attributes of the finished product. In some embodiments, the thermoplastic can be recycled thermoplastic from waste products, discarded products, or other applications.

[0046] The term "polymeric material" as used herein refers to an injection molded substrate, which may include one or more thermoplastics and, optionally, additional additives such as color pigments, glitter, finishing surface chemicals, utility additives, and mixtures thereof.

[0047] The term "thermoplastic polyurethane ("TPU")" as used herein refers to a type of thermoplastic produced from block copolymers consisting of alternating sequences of hard (high polarity) and soft (low polarity) domains formed by the reaction of diisocyanates with short chain diols and diisocyanates with long chain diols. TPUs are generally characterized by high durability, flexibility, and tensile strength.

[0048] TPUs are available in several hardness grades, measured by the Shore A and / or Shore D values ​​of the TPU, which are determined according to ASTM D2240. TPUs with hardness values ​​of about 10A to 50A are very soft, TPUs with hardness values ​​of 50A to 80A are soft, TPUs with hardness values ​​of 80A to 90A are medium, TPUs with hardness values ​​of 90 to 95A are hard, and TPUs with hardness values ​​of 60D to 75D are very hard. The term "TPU90" refers to a TPU with a Shore A value of 90. The term "TPU95" refers to a TPU with a Shore A value of 95.

[0049] Other defining properties of a TPU or blend of TPUs include density (e.g., as measured by ASTM D792), tensile strength and elongation at break (e.g., as measured by ASTM D412), abrasion (e.g., as measured by ISO 4649), and tear strength (e.g., as measured by ASTM D624). The most suitable TPU or blend of TPUs for a particular product will depend on the application, manufacturing method, and desired physical attributes of the finished product.

[0050] The term "additive" refers to any substance added to a thermoplastic or mixture of thermoplastics to improve, modify, or preserve the attributes of a given manufactured article. In embodiments of the present invention, any number of suitable additives may be used alone or in combination, provided that the additives achieve their intended purpose and do not adversely affect the performance characteristics of the helmet cover to a significant extent. Exemplary additives include, but are not limited to, color pigments, finishing surface chemicals, utility additives, and mixtures thereof. When present, additives may be employed in any suitable amount, provided that the additives achieve their intended purpose and do not adversely affect the performance characteristics of the helmet cover to a significant extent.

[0051] The term "thickness" as used herein refers to the distance between opposing surfaces. For example, in certain embodiments, the term "thickness" refers to the distance between an inner surface of a helmet cover and an outer surface of the helmet cover. Although various thicknesses are disclosed, it is understood that the process for manufacturing the articles is subject to natural process variations and therefore reasonable variations from the desired thickness are within the scope of the present disclosure. For example, regardless of whether the unitary shell assembly described herein has a single or multiple thicknesses, each of the one or more thicknesses will typically be between 0.25 mm and 4 mm.

[0052] The term "up to" as used herein refers to a value less than the indicated value and greater than zero (i.e., would not include the value zero (0)). For example, in reference to a unitary shell assembly described herein having a thickness of up to 4 mm, the thickness would be below 4 mm and greater than zero.

[0053] The terms "injection molding" or "injection molded" as used herein refer to a manufacturing process for producing an article by injecting molten material into an injection mold tool. The material for the article, such as a thermoplastic or a mixture of thermoplastics, is fed into a polymer injection unit, melted, and injected into the mold cavity through a nozzle in fluid communication with both the polymer injection unit and the mold cavity, where it is then cooled to configure the shape of the mold cavity.

[0054] The term "polymeric injection unit" as used herein refers to a unit operation for melting polymeric material during injection molding. Although various configurations are known in the art, the unit generally includes a barrel-mounted screw assembly, a processing space, and one or more nozzles in fluid communication with the processing space. The polymeric injection unit may also include a hopper assembly for introducing the polymeric material into the processing space. In an embodiment, the hopper assembly includes a conical hopper, a hopper block disposed within the processing space to support the conical hopper, and optionally a hopper heater and dryer for adjusting the moisture content of the polymeric material prior to feeding. The polymeric injection unit may additionally include a vent or port for reducing the water and / or volatile moisture content of the polymeric material.

[0055] The term "barrel-mounted screw assembly" as used herein refers to a cylinder with a helical channel that is mounted within the processing space of a polymer injection unit.

[0056] The term "processing space" as used herein refers to the hollow chamber within the polymer injection unit in which the barrel mounted screw assembly operates.

[0057] The term "nozzle" as used herein refers to a tubular section used to inject polymeric material into an injection mold tool.

[0058] The term "injection mold tool" as used herein refers to an assembly of parts that allows a molten polymeric material to be formed and cooled to produce a discrete manufactured article, such as a helmet cover. The injection mold tool includes a mold cavity.

[0059] The term "mold cavity" as used herein refers to the portion of an injection mold tool that imparts the shape of the article of manufacture to the molten polymeric material upon cooling. The mold cavity includes a hollow portion and a core portion, which together provide the shape of the article of manufacture. In the manufacture of helmet covers, the hollow portion of the mold cavity provides the shape of the outer surface of the helmet cover, while the core portion provides the shape of the inner surface of the helmet cover.

[0060] The term "in communication with" as used herein refers to the ability to move between two or more units or manufacturing steps. By way of example, when one unit or manufacturing step is "in fluid communication" with another unit or manufacturing step, it is meant that a fluid (such as a molten polymeric material) can move between the two units.

[0061] The term "predefined" as used herein refers to a set point that is established in advance. For example, the term "predefined temperature" refers to a desired temperature set point. As another example, the term "predefined pressure" refers to a desired pressure set point. The predefined set point may be determined based on the specifications of the manufacturing process, such as the melting point of a polymeric material. Although various predefined set points are disclosed, it should be understood that processes for manufacturing articles are subject to variation in set points and thus reasonable deviations from the desired predefined values ​​are within the scope of the present disclosure.

[0062] The term "progressive gradient" as used herein refers to a series of predetermined variables that vary in steps. For example, the term "progressive pressure gradient" refers to a series of predetermined pressures that are achieved in sequence. Although various predetermined set points for the progressive gradient are disclosed, it is understood that the process for manufacturing the article is subject to variation in the set points and therefore reasonable deviations from the desired progressive gradient are within the scope of the present disclosure.

[0063] The term "backpressure" as used herein refers to the amount of pressure that the polymeric material exerts on the barrel-mounted screw assembly during melting.

[0064] The term "holding pressure" as used herein refers to the amount of pressure applied during the final stage of filling the mold cavity. In some embodiments, holding pressure is applied when the mold cavity is about 90-99% filled by volume. In some embodiments, holding pressure is applied when the mold cavity is about 95-99% filled by volume. In some embodiments, holding pressure is applied when the mold cavity is about 99% filled by volume.

[0065] The term "injecting" as used herein refers to the process of forcing molten polymeric material through one or more nozzles into a mold cavity of an injection molding tool.

[0066] The term "cooling" as used herein refers to the process of solidifying molten polymeric material within the mold cavity of the injection molding tool.

[0067] The term "extracting" as used herein refers to the process of removing cooled polymeric material from within the mold cavity of an injection mold tool to provide a desired article of manufacture, such as a helmet cover. Extraction can be performed manually, robotically, or using specialized tools.

[0068] The term "helmet geometry file" refers to a computerized model, such as a CAD representation, taken of a helmet.

[0069] The term "helmet cover geometry file" refers to a modified helmet geometry file.

[0070] The term "3-dimensional helmet cover prototype" refers to a physical representation of a helmet cover geometric shape file obtained by three-dimensional printing.

[0071] The term "altering" refers to changing the structure, design, and / or dimensions of an object.

[0072] The term "adjusting" refers to a slight manipulation that improves the fit and / or appearance of an object.

[0073] 1, a helmet cover 100 and a helmet 102 are illustrated. The helmet 102 includes one or more helmet openings 104 and one or more helmet fastening locations 106. The helmet cover 100 is designed to have a shape that closely resembles the shape of the helmet 102 and includes the optional helmet openings 104 and helmet fastening locations 106. For example, as shown in FIGS. 1-2, the helmet cover 100 includes one or more openings 108 that correspond to the helmet openings 104. Similarly, the helmet cover 100 includes one or more openings 108 that correspond to the helmet fastening locations 106.

[0074] 1-2, the helmet cover 100 is sized to slide over the outer surface of the helmet 102 so as to conformably cover the outer surface of the helmet 102. While the helmet cover 100 may be removed from the helmet 102, the fit between the helmet cover 100 and the helmet 102 is such that the helmet cover 102 will not be removed from the helmet 100 without the application of a pulling force. Because the helmet cover 100 is formed to conformably cover the outer surface of the helmet 102, adjustable fasteners are not required to achieve the desired fit between the helmet cover 100 and the helmet 102.

[0075] 3A-E, the helmet cover 100 of the present invention includes a unitary shell assembly 202. The unitary shell assembly 202 includes an inner surface 204, an outer surface 206, and a receiving cavity 208. The receiving cavity 208 has a shape and size that closely resembles the shape and size of the outer surface of the helmet 102.

[0076] The helmet cover 100 can be made from a thermoplastic, a blend of thermoplastics, or one or more thermoplastics and one or more additives. Exemplary thermoplastics include polyurethane ("TPU"), polypropylene ("PP"), polyethylene ("PE"), polystyrene ("PS"), polyvinyl chloride ("PVC"), poly(methyl methacrylate) ("PMMA"), polycarbonate ("PC"), polyoxymethylene ("POM"), polyethylene vinyl acetate ("PEVA"), high density polyethylene ("HDPE"), acrylonitrile butadiene styrene ("ABS"), polyamide ("PA nylon"), or blends thereof. For example, the helmet cover 100 can be made from one or more TPUs. Exemplary additives include, but are not limited to, color pigments, finishing surface chemicals, utility additives, and blends thereof. In an embodiment, the helmet cover 100 is made from TPU90, TPU95, or blends thereof.

[0077] As shown in FIG. 4, in an embodiment, the unitary shell assembly 202 of the helmet cover 100 further includes a gripping member 300. The gripping member 300 is formed to provide a clip 304 sized to accommodate the outer edge of the outer surface of the helmet 102. The gripping member 300 is designed so that it can be snap-fitted to the outer edge of the outer surface of the helmet 102, thus providing a secure and partially encircling fit with said outer edge. The gripping member 300 can be designed to accommodate the entire outer edge of the outer surface of the helmet 102, or it can be designed to accommodate only a certain outer edge of the outer surface of the helmet 102, the outer edge being selected according to the desired appearance of the helmet cover 100.

[0078] As shown in FIG. 5, the helmet cover 100 may further include a finish layer 400. It is understood that one of ordinary skill in the art would recognize any number of suitable finish layers, and that any such finish layer may be used as long as it withstands the applied forces and intended use. For example, the finish layer 400 may include one or more of a paint, a powder coating, a protective coating, a graphic, a thin film formulation, or a combination thereof. The finish layer 400 may be applied by painting, bead blasting, etching, UV curing, silk screening, hydro-dipping, physical vapor deposition, or other known application techniques.

[0079] The inner surface 204 and / or the outer surface 206 of the helmet cover 100 may include a plurality of micropores. When applied to the inner surface 204 and / or the outer surface 206, the plurality of micropores may improve the surface properties of the inner surface 204 and / or the outer surface 206. For example, the micropores may modify the coefficient of friction experienced by the inner surface 204 and / or the outer surface 206 or may modify the porosity of the inner surface 204 and / or the outer surface 206 and promote adhesion of the finishing layer 400. The micropores may be provided on the inner surface 204 and / or the outer surface 206 as part of the injection molding process or by a mechanical or laser process after the injection molding is completed. The diameter, density, and location of the micropores may be varied to achieve the desired surface properties.

[0080] The helmet cover 100 of the present invention may generally be manufactured according to known methods for manufacturing articles made from thermoplastics, such as injection molding, thermoforming, and the like.

[0081] For example, the helmet cover 100 may be manufactured via an injection molding process. As shown in Figure 6, the injection molding method 600 includes (602) introducing a polymeric material, (604) melting the polymeric material, (606) injecting the polymeric material, (608) cooling the polymeric material, (610) extracting the polymeric material, and (612) providing a helmet cover.

[0082] As shown in FIG. 7, in an embodiment, step 602: introducing polymer material is accomplished by feeding polymer material 710 into a polymer injection unit 700. In an embodiment, the polymer injection unit 700 includes a processing space 704, a barrel-mounted screw assembly 702, and one or more nozzles 706 in fluid communication with both the processing space 704 and the injection mold tool 800. The polymer injection unit may optionally include a hopper assembly 708 for introducing the polymer material 710 into the processing space 704. The hopper assembly 708 may optionally include a conical hopper, a hopper block disposed within the processing space to support the conical hopper, and optionally a hopper heater and dryer for adjusting the moisture content of the polymer material prior to feeding. The polymer injection unit 700 may also optionally include a vent or port for reducing the water and / or volatile moisture content of the polymer material 710.

[0083] Step 602: During introduction of the polymer material, the barrel-mounted screw assembly 702 rotates within the processing space 704 and transports the polymer material 710 in a proximal-to-distal direction through the processing space, whereby the interaction between the barrel-mounted screw assembly and the processing space generally produces axial (i.e., forward) motion of the polymer material.

[0084] 6 and 7, during step 604, i.e., melting the polymeric material, the barrel-mounted screw assembly 702 and the outer limit of the processing space 704 (commonly referred to as the barrel) interact to melt, convey, and apply pressure thereon to the polymeric material, preparing the polymeric material 710 for step 606: injecting the polymeric material. To facilitate the interaction, the barrel of the processing space 704 may be partially grooved or entirely grooved, depending on the application. Similarly, the length, diameter, and rotational speed of the barrel-mounted screw assembly 702 may be varied to obtain desired melting characteristics and consistent output. In an embodiment, the barrel-mounted screw assembly 702 may include one or more zones where the diameter of the screw or the pitch of the helical channel may be varied to provide the appropriate feed rate, compression, and metering. The melt uniformity of the polymeric material 710 may also be varied by predefining the force generated by the barrel-mounted screw 702, also referred to as back pressure.

[0085] The processing space 704 may additionally have one or more barrel sections 712, each with its own temperature set point for bringing the polymeric material 710 to a first predetermined temperature for step 604: melting the polymeric material. The first predetermined temperature may be a specific temperature set point or may be a temperature gradient. It should be understood that the temperature set point for each of the one or more barrel sections 712 may be varied according to the processing specifications of the polymeric material 710.

[0086] When more than one barrel section 712 is included within the processing space, generally the barrel section 712 on the proximal end (712a) of the processing space will have the lowest temperature set point to prevent premature melting and crosslinking during step 602: introducing polymeric material. The temperature of the remaining barrel sections 712 can then be varied in a direction proceeding from the proximal end to the distal end of the processing space, for example, by increasing the barrel section temperature set point in the distal direction. In this manner, the temperature set points increase as one moves from 712a, 712b, 712c, and 712d. For example, in an embodiment, the temperature set points can be 200±5° C. for barrel section 712a, 215±5° C. for barrel section 712b, 225±5° C. for barrel section 712c, and 230±5° C. for barrel section 712d.

[0087] 6 and 7, during step 606: injecting polymer material, polymer material 710 is forced through one or more nozzles 706 and introduced into injection mold tool 800. As shown in FIG. 8, in one embodiment, injection mold tool 800 includes a positioning ring 802, a sprue bushing 804, a spacer plate 806, guide posts 808 and guide bushings 810, a runner 824, a mold cavity 812, a stationary plate 818, a movable plate 820, a core retaining plate 822, an ejector pin 826, an ejector plate 828, and a clamp plate 830. Mold cavity 812 includes one or more cavity portions 814 and a core portion 816.

[0088] 6-8 , when performing the injection molding method 600, the one or more nozzles 706, sprue bushing 804, and runners 824 are in communication so that the polymer material 710 can be forced from the processing space 704 into the mold cavity 812 to fill the mold cavity 812. In one embodiment, during step 606: injecting the polymer material, the mold cavity 812 is filled in two phases referred to as a filling / packing phase and a holding phase.

[0089] During the filling / packing stage, the molten polymeric material 710 is injected under a first progressive pressure gradient that is provided to fill the form and then allow for contraction and backflow of the molten polymeric material 710. In one embodiment, the progressive pressure gradient is between about 70 bar and 15 bar.

[0090] During the holding stage, the molten polymeric material 710 is held at a particular holding pressure until no additional polymeric material 710 flows into the mold cavity 812. The holding pressure can be varied depending on the processing specifications of the polymeric material 710 and can be a pressure gradient. The holding pressure is applied when the mold cavity 812 is approximately 90-99% filled by volume.

[0091] 6, during step 608: cooling the polymeric material, the polymeric material 710 in the mold cavity 812 is cooled to a second predetermined temperature. It should be understood that the second predetermined temperature may be varied according to the processing specifications of the polymeric material 710. The second predetermined temperature may be achieved by cooling the cavity portion 814 and the core portion 816 to a particular temperature set point. The temperature set points for the cavity portion 814 and the core portion 816 may be the same or different depending on the process. For example, the temperature set points for the cavity portion 814 and the core portion 816 may be within a range of 60°C ± 10°C.

[0092] 6, during step 610: extracting the polymer material, the helmet cover 100 is removed from the mold cavity 812 and the injection mold tool 800. Step 610: extracting the polymer material can be accomplished by use of the ejector pins 826 and ejector plate 828, by manual extraction, or both. Finally, during step 612, i.e., providing a helmet cover, the helmet cover 100 is provided according to embodiments described herein.

[0093] 9, the injection mold tool 800 can be designed and provided via a method for providing the tool 900. In an embodiment, the method for providing the tool 900 includes (902) scanning the helmet 102 to obtain a helmet geometry file, (904) modifying the helmet geometry file to form a helmet cover geometry file, (906) printing a three-dimensional helmet cover prototype from the helmet cover geometry file, (908) adjusting the helmet cover geometry file, and (910) generating the injection mold tool 800 using the helmet cover geometry file.

[0094] During step 902, i.e., scanning the helmet 102 to obtain a helmet geometry file, the helmet 102 is scanned and a computerized model of the helmet 102 is generated. In an embodiment, the computerized model may be a CAD STEP file. For example, the helmet geometry file may be generated by scanning the helmet 102, obtaining associated surface measurements, and generating a CAD model using known methods of surface measurement and surface data output. These methods include generating a point cloud or mesh data output. Point cloud data is provided by applying pulses of laser light to the surface of the object, measuring the amount of time it takes each pulse to reflect back to the scanner, and using the time measurements to determine the exact location of the scanned object's points. Mesh data is obtained by subdividing the surface structure into a set of polygons, which divide the continuous surface into vertices, edges, and faces, which may be represented in the computerized model.

[0095] Step 904: Modifying the helmet geometry file to form a helmet cover geometry file During this, the helmet geometry file is manipulated to generate a helmet cover geometry file. The modification may include manipulating the size, shape, and / or structure of the helmet 102 depicted in the geometry file. The modification may include manipulating the thickness of the helmet geometry file, adding one or more openings to the helmet geometry file, adding one or more gripping members to the helmet geometry file, adding a plurality of micro holes to the helmet geometry file, or a combination thereof. The file resulting from the modification applied to the helmet geometry file is referred to as a helmet cover geometry file.

[0096] For example, during step 904: modifying the helmet geometry file to form the helmet cover geometry file, the helmet geometry file may be modified by manipulating the size and shape of the helmet 102 depicted in the helmet geometry file to obtain the helmet cover geometry file. To manipulate the size, the helmet geometry file is expanded in all directions in an amount equivalent to the desired thickness of the helmet cover 100. To manipulate the shape, the expanded helmet geometry file is then modified to skive the inner surface depicted in the helmet geometry file, thereby causing the final product to have a total thickness equivalent to the desired thickness of the helmet cover 100. Manipulating the size and shape of the helmet geometry file in this manner to generate the helmet cover geometry file allows the finished helmet cover 100 to slide over the helmet 102, rather than "stack" on top of the helmet 102. Certain types of size and shape manipulations also preserve the helmet-like shape of the helmet cover 100, which ensures that the helmet cover 100 fits snugly over the helmet 102 despite the large and irregular shapes of both the helmet cover 102 and the helmet 100. Additional modifications can then be made to the helmet geometry file, such as adding one or more openings to the helmet geometry file, adding one or more gripping members to the helmet geometry file, adding micro-holes to the helmet geometry file, or combinations thereof. The end product of the modifications is a helmet cover geometry file.

[0097] During step 906, i.e., printing a three-dimensional helmet cover prototype from the helmet cover geometry file, a three-dimensional helmet cover prototype corresponding to the helmet cover geometry file is provided. The three-dimensional helmet cover prototype allows the manufacturer to check the fit of the three-dimensional helmet cover prototype when it is applied to the helmet 102 and to note any areas that require adjustment. During step 908: adjusting the helmet cover geometry file, the helmet cover geometry file is adjusted to provide an improved fit of the helmet cover 100 compared to the three-dimensional helmet cover prototype. Step 906: printing a three-dimensional helmet cover prototype from the helmet cover geometry file and step 908: adjusting the helmet cover geometry file can be repeated as many times as necessary to achieve the desired fit and design of the helmet cover 100 when it is applied to the helmet 102.

[0098] Once the desired fit and design of the helmet cover geometry file is achieved, step 910: generating an injection mold tool 800 using the helmet cover geometry file is performed. The injection mold tool 800 is designed to provide the desired helmet cover 100 while also accommodating required process attributes such as injection flow rate, removal of molded article, temperature and pressure control, etc. The injection mold tool is designed according to the instructions set forth herein.

[0099] (Embodiment) (Helmet cover) Aspects of the invention relate to a helmet cover made from a unitary shell assembly including a receiving cavity, an inner surface, and an outer surface. The receiving cavity is configured such that the inner surface of the unitary shell assembly is configured to contact the outer surface of the helmet. The unitary shell assembly fitably and removably covers the outer surface of the helmet.

[0100] Another aspect of the invention relates to a helmet cover including a unitary shell assembly. The unitary shell assembly includes a receiving cavity, an inner surface, an outer surface, and a gripping member. The receiving cavity is configured such that the inner surface of the unitary shell assembly is configured to contact an outer surface of the helmet. The unitary shell assembly conformably and removably covers the outer surface of the helmet and is snap-fittably attached to an outer edge of the outer surface of the helmet through the use of the gripping member.

[0101] The specific embodiments describing components, materials, ranges, values, and steps provided below are for illustrative purposes only and do not otherwise limit the scope of the disclosed subject matter, as defined by the claims.

[0102] In various embodiments, the one-piece shell assembly fitably and removably covers the exterior surface of the helmet without the use of adjustable fasteners.

[0103] In various embodiments, the helmet cover also includes a finish layer adhered to the outer surface of the unitary shell assembly. The finish layer includes any suitable finish or mixture of finishes, provided that the finish does not interfere with the desired attributes of the helmet cover, such as fit, ability to apply the finish, durability of the finish, or manufacturing method. In some embodiments, the finish layer includes paint, powder coating, graphics, thin film formulations, or combinations thereof. The finish layer may be applied by painting, bead blasting, etching, UV curing, silk screening, hydro-dipping, physical vapor deposition, or combinations thereof.

[0104] In various embodiments, the unitary shell assembly further includes one or more openings therethrough. The one or more openings may correspond to one or more openings in the helmet. In certain embodiments, the one or more openings provide access to various helmet features.

[0105] In various embodiments, the unitary shell assembly further includes a gripping member. In certain embodiments, the gripping member is snap-fitably attached to the outer edge of the helmet's outer surface, thus providing a secure and partially encircling fit therewith. The gripping member is formed to provide a lip sized to accommodate the outer edge of the helmet's outer surface. The gripping member can be designed to accommodate the entire outer edge of the helmet's outer surface, or only a certain outer edge of the helmet's outer surface, the outer edge being selected according to the desired appearance and fit of the helmet cover.

[0106] In various embodiments, the unitary shell assembly is made from a thermoplastic. In some embodiments, the thermoplastic is formed via injection molding or thermoforming. In some embodiments, the thermoplastic is polyurethane ("TPU"), polypropylene ("PP"), polyethylene ("PE"), polystyrene ("PS"), polyvinyl chloride ("PVC"), poly(methyl methacrylate) ("PMMA"), polycarbonate ("PC"), polyoxymethylene ("POM"), polyethylene vinyl acetate ("PEVA"), high density polyethylene ("HDPE"), acrylonitrile butadiene styrene ("ABS"), polyamide ("PA nylon"), or a mixture thereof. For example, the unitary shell assembly can be made from one or more TPUs. In some embodiments, the TPU is TPU90, TPU95, or a mixture thereof.

[0107] In various embodiments, the unitary shell assembly is made of a thermoplastic and one or more additives. The one or more additives may include any suitable additive or mixture of additives, provided that the additive does not interfere with the desired attributes of the helmet cover, such as fit, ability to apply a finish, durability of the finish, or manufacturing method. In some embodiments, the one or more additives may include color pigments, glitter, finish surface chemicals, utility additives, and mixtures thereof. In some embodiments, the utility additive may include graphite, micro vacuum spheres, or mixtures thereof.

[0108] In specific embodiments, the inner surface of the unitary shell assembly and / or the outer surface of the unitary shell assembly include a plurality of micropores. The plurality of micropores are positioned and sized to facilitate insertion of a protective helmet. For example, in some embodiments, the plurality of micropores are positioned and sized to facilitate adhesion of a finish layer present on the outer surface of the unitary shell assembly. The plurality of micropores may cover all or a portion of the inner surface of the unitary shell assembly and / or the outer surface of the unitary shell assembly. In some embodiments, the plurality of micropores preferably each independently have a diameter of 0.1 μm to 10 μm. In some embodiments, the plurality of micropores preferably each independently have a diameter of 0.5 μm to 5 μm. In some embodiments, the plurality of micropores preferably each independently have a diameter of about 1 μm ± 0.5 μm. In some embodiments, the plurality of micropores may have a density of 3.2e9 to 3.2e5 micropores / cm. 2 In one embodiment, the plurality of micropores has a distribution of 1.3e8 to 1.3e6 micropores / cm 2 In one embodiment, the plurality of micropores has a distribution of about 3.2e7 micropores / cm 2 It has a distribution of

[0109] As a manufactured product, the unitary shell assembly of the helmet cover will have a particular thickness. Within the unitary shell assembly, the thickness may vary from section to section, or it may be consistent throughout. Whether the unitary shell assembly is of a single thickness or multiple thicknesses, each of the one or more thicknesses may be between 0.25 mm and 4 mm. For example, each of the one or more thicknesses may be up to 4 mm. Specifically, each of the one or more thicknesses may be up to 3 mm. More specifically, each of the one or more thicknesses may be up to 2 mm. More specifically, each of the one or more thicknesses may be up to 1.75 mm. More specifically, each of the one or more thicknesses may be up to 1.5 mm. More specifically, each of the one or more thicknesses may be up to 1.25 mm.

[0110] Similarly, each of the one or more thicknesses can be greater than 0.25 mm. For example, each of the one or more thicknesses can be greater than 0.5 mm. Specifically, each of the one or more thicknesses can be greater than 0.75 mm. More specifically, each of the one or more thicknesses can be greater than 1 mm.

[0111] In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.75 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.5 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.25 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.2 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.15 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.1 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.09 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.08 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.07 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.06 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.05 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.04 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.03 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.02 mm. In some embodiments, the unitary shell assembly has a thickness of 1 mm ± 0.01 mm. In some embodiments, the unitary shell assembly has a thickness of about 1 mm.

[0112] (Method of manufacturing a helmet cover) Another aspect of the invention is a method of manufacturing a helmet cover, the method including providing a polymer injection unit in a processing space, providing an injection molding tool having a mold cavity, introducing a polymer material into the processing space, melting the polymer material in the processing space, injecting a volume of the polymer material into the mold cavity of the injection molding tool, cooling the polymer material in the mold cavity of the injection molding tool, and extracting the polymer material from the injection mold tool of the injection molding tool to provide the helmet cover.

[0113] Another aspect of the invention is a method of manufacturing a helmet cover, the method including providing a polymer injection unit, providing an injection mold tool, introducing a polymer material into a treatment space, melting the polymer material in the treatment space, injecting a volume of the polymer material, cooling the polymer material, extracting the polymer material, and providing a helmet cover.

[0114] The polymer injection unit includes a barrel-mounted screw assembly, a processing space with a distal end and a proximal end, and one or more nozzles in fluid communication with the processing space located at the distal end of the processing space. The polymer material is melted in the processing space by using a screw mounted in the barrel to mix the polymer material, applying a heat source to bring the polymer material to a first predetermined temperature, and creating a predetermined back pressure. Once melted, the polymer material is injected into an injection mold tool through the one or more nozzles.

[0115] The injection mold tool includes a mold cavity in fluid communication with one or more nozzles and is constructed to form the helmet cover in one piece. When the polymeric material is injected, it is injected in an amount that is sufficient to fill the mold cavity. The polymeric material is then cooled within the mold cavity to a second predetermined temperature. Upon cooling, the polymeric material is extracted from the mold cavity to provide the helmet cover.

[0116] Another aspect of the present invention is a method of providing an injection molding tool. To provide an injection mold tool, a helmet is scanned to obtain a helmet geometry file. The helmet geometry file is modified to form a helmet cover geometry file. Modifying the helmet geometry file may include one or more of manipulating the size of the helmet cover, modifying the structure of the helmet cover, adding one or more gripping members to the helmet cover, and / or adding a plurality of micro-holes to the helmet cover. Using the helmet cover geometry file, a helmet cover prototype is generated via three-dimensional printing. Based on the fit of the helmet cover prototype, the helmet cover geometry file is adjusted to provide an improved fit of the helmet cover compared to the three-dimensional helmet cover prototype. The prototyping and adjusting are repeated until a desired fit and design for the helmet cover is achieved, and then an injection mold tool is generated using the helmet cover geometry file.

[0117] The specific embodiments describing components, materials, ranges, values, and steps provided below are for illustrative purposes only and do not otherwise limit the scope of the disclosed subject matter, as defined by the claims.

[0118] In various embodiments, the polymeric material comprises a thermoplastic. In some embodiments, the polymeric material comprises a thermoplastic, such as polyurethane ("TPU"), polypropylene ("PP"), polyethylene ("PE"), polystyrene ("PS"), polyvinyl chloride ("PVC"), poly(methyl methacrylate) ("PMMA"), polycarbonate ("PC"), polyoxymethylene ("POM"), polyethylene vinyl acetate ("PEVA"), high density polyethylene ("HDPE"), acrylonitrile butadiene styrene ("ABS"), polyamide ("PA nylon"), or mixtures thereof. For example, the polymeric material may comprise one or more TPUs. In some embodiments, the TPU is TPU90, TPU95, or mixtures thereof.

[0119] In various embodiments, the polymeric material includes a thermoplastic and one or more additives. The one or more additives may include any suitable additive or mixture of additives, provided that the additive does not interfere with the desired attributes of the helmet cover, such as fit, ability to apply a finish, durability of the finish, or manufacturing method. In some embodiments, the one or more additives may include color pigments, glitter, finish surface chemicals, utility additives, and mixtures thereof. In some embodiments, the utility additive may include graphite, micro vacuum spheres, or mixtures thereof.

[0120] In various embodiments, the method of manufacturing the helmet cover further comprises providing micro-holes on the helmet cover. In some embodiments, the mold cavity is formed to provide micro-holes on the helmet cover. In some embodiments, providing micro-holes on the helmet cover is accomplished via a mechanical process or a laser drilling process after extracting the polymeric material from the mold cavity. The micro-holes are positioned and sized to facilitate insertion of a protective helmet. For example, in some embodiments, the micro-holes are positioned and sized to facilitate adhesion of a finish layer present on the outer surface of the unitary shell assembly. The micro-holes may cover all or a portion of the inner surface of the unitary shell assembly and / or the outer surface of the unitary shell assembly. In some embodiments, the method of manufacturing the helmet cover further comprises providing micro-holes having a diameter of 0.1 μm to 10 μm. In some embodiments, the method of manufacturing the helmet cover further comprises providing micro-holes having a diameter of 0.5 μm to 5 μm. In some embodiments, the method of manufacturing the helmet cover further comprises providing micro-holes having a diameter of 1 μm to ±0.5 μm. In one embodiment, the method for manufacturing the helmet cover has a microhole density of 3.2e9 to 3.2e5 microholes / cm 2 In one embodiment, the method for making a helmet cover further includes providing micropores having a distribution of 1.3e8 to 1.3e6 micropores / cm. 2 In one embodiment, the method for making a helmet cover further includes providing micropores having a distribution of about 3.2e7 micropores / cm. 2 In various embodiments, the micropores may cover all or a portion of the inner surface of the unitary shell assembly, the outer surface of the unitary shell assembly, or both.

[0121] In various embodiments, a method of manufacturing a helmet cover includes melting a polymeric material in a processing space by bringing the material to a first predetermined temperature. In some embodiments, the first predetermined temperature is 230±30°C. In some embodiments, the first predetermined temperature is 230±20°C. In some embodiments, the first predetermined temperature is 230±15°C. In some embodiments, the first predetermined temperature is 230±10°C. In some embodiments, the first predetermined temperature is 230±5°C. In some embodiments, the first predetermined temperature is 230±3°C.

[0122] In various embodiments, a method of manufacturing a helmet cover includes creating a predetermined backpressure while melting a polymeric material in a processing space. In some embodiments, the predetermined backpressure is less than about 20 bar. In some embodiments, the predetermined backpressure is less than about 15 bar. In some embodiments, the predetermined backpressure is less than about 10 bar. In some embodiments, the predetermined backpressure is 5±1 bar.

[0123] In various embodiments, the method of manufacturing a helmet cover includes cooling the polymeric material in the mold cavity to a second predetermined temperature. In some embodiments, the second predetermined temperature is 60±10° C. In some embodiments, the second predetermined temperature is 60±8° C. In some embodiments, the second predetermined temperature is 60±6° C. In some embodiments, the second predetermined temperature is 60±4° C. In some embodiments, the second predetermined temperature is 60±2° C.

[0124] In various embodiments, a method of manufacturing a helmet cover includes injecting a volume of polymeric material, which is accomplished by applying a first progressive pressure gradient. In some embodiments, the progressive pressure gradient is from about 80 bar to about 10 bar. In some embodiments, the progressive pressure gradient is from about 70 bar to about 15 bar.

[0125] In various embodiments, injecting the volume of polymeric material occurs within 20±20 seconds. In some embodiments, injecting the volume of polymeric material occurs within 20±15 seconds. In some embodiments, injecting the volume of polymeric material occurs within 20±10 seconds. In some embodiments, injecting the volume of polymeric material occurs within 20±5 seconds.

[0126] In various embodiments, cooling the polymeric material within the mold cavity occurs within 60±20 seconds. In some embodiments, cooling the polymeric material within the mold cavity occurs within 60±15 seconds. In some embodiments, cooling the polymeric material within the mold cavity occurs within 60±10 seconds. In some embodiments, cooling the polymeric material within the mold cavity occurs within 60±5 seconds.

[0127] In various embodiments, introducing the polymeric material into the processing space, melting the polymeric material in the processing space, injecting a volume of the polymeric material into the mold cavity through one or more nozzles, and cooling the polymeric material in the mold cavity occur within 130±40 seconds. In some embodiments, melting the polymeric material in the processing space, injecting a volume of the polymeric material into the mold cavity through one or more nozzles, and cooling the polymeric material in the mold cavity occur within 130±30 seconds. In some embodiments, melting the polymeric material in the processing space, injecting a volume of the polymeric material into the mold cavity through one or more nozzles, and cooling the polymeric material in the mold cavity occur within 130±20 seconds. In some embodiments, melting the polymeric material in the processing space, injecting a volume of the polymeric material into the mold cavity through one or more nozzles, and cooling the polymeric material in the mold cavity occur within 130±10 seconds.

[0128] In various embodiments, injecting a volume of polymeric material into the mold cavity through one or more nozzles further comprises holding the mold cavity at a holding pressure when the mold cavity is about 90-99% filled by volume. In some embodiments, the holding pressure is 100±10 bar. In some embodiments, the holding pressure is 100±5 bar. In some embodiments, holding the mold cavity at a holding pressure occurs when the mold cavity is about 95-99% filled by volume. In some embodiments, holding the mold cavity at a holding pressure occurs when the mold cavity is about 99% filled by volume.

[0129] Enumerated Embodiments The specific recited embodiments 1-70 provided below are for illustrative purposes only and do not otherwise limit the scope of the disclosed subject matter, as defined by the claims. These recited embodiments include all combinations, subcombinations, and multiple reference (e.g., multiple dependent) combinations described therein.

[0130] (Enumerated embodiments relating to helmet covers) Embodiment 1: A helmet cover, the helmet cover including a unitary shell assembly including a receiving cavity, an inner surface, and an outer surface, the receiving cavity configured such that the inner surface of the unitary shell assembly is configured to contact an outer surface of the helmet, and the unitary shell assembly fitably and removably covers the outer surface of the helmet.

[0131] Embodiment 2: A helmet cover as described in embodiment 1, wherein the one-piece shell assembly can fitably and removably cover the outer surface of the helmet without the use of adjustable fasteners.

[0132] Embodiment 3: The helmet cover of embodiment 1, further comprising a finishing layer adhered to the outer surface of the unitary shell assembly.

[0133]

[0026] Embodiment 4: A helmet according to any one of embodiments 1-3, wherein the unitary shell assembly further includes one or more openings therethrough corresponding to one or more openings in the helmet. Helmet cover.

[0134] Embodiment 5: A helmet cover described in any one of embodiments 1-4, wherein the unitary shell assembly further includes a gripping member.

[0135] Embodiment 6: A helmet cover as described in embodiment 5, wherein the gripping member is snap-fittably attached to the outer edge of the outer surface of the helmet.

[0136] Embodiment 7: A helmet cover described in any one of embodiments 1-5, wherein the unitary shell assembly is made from a thermoplastic.

[0137] Embodiment 8: The helmet cover of embodiment 7, wherein the thermoplastic is polyurethane ("TPU"), polypropylene ("PP"), polyethylene ("PE"), polystyrene ("PS"), polyvinyl chloride ("PVC"), poly(methyl methacrylate) ("PMMA"), polycarbonate ("PC"), polyoxymethylene ("POM"), polyethylene vinyl acetate ("PEVA"), high density polyethylene ("HDPE"), acrylonitrile butadiene styrene ("ABS"), polyamide ("PA nylon"), or a mixture thereof.

[0138] Embodiment 9: A helmet cover as described in embodiment 8, wherein the thermoplastic is TPU.

[0139] Embodiment 10: A helmet cover according to embodiment 9, wherein the TPU is TPU90, TPU95, or a mixture.

[0140] Embodiment 11: A helmet cover described in any one of embodiments 7-10, wherein the unitary shell assembly is made from a thermoplastic, and the thermoplastic is present in at least 95% by weight.

[0141] Embodiment 12: A helmet cover described in any one of embodiments 7-11, wherein the unitary shell assembly is made from a thermoplastic, and the thermoplastic is present at at least 99% by weight.

[0142] Embodiment 13: A helmet cover as described in any one of embodiments 7-12, wherein the unitary shell assembly is made from thermoplastic, the thermoplastic including recycled thermoplastic from discarded and / or unused products.

[0143] Embodiment 14: A helmet cover according to any one of embodiments 1-13, wherein the unitary shell assembly is made from a thermoplastic and one or more additives.

[0144] Embodiment 15: The helmet cover of embodiment 14, wherein the one or more additives include color pigments, glitter, finishing surface chemicals, utility additives, and mixtures thereof.

[0145] Embodiment 16: The method according to any one of embodiments 1-15, wherein the inner surface of the unitary shell assembly, the outer surface of the unitary shell assembly, or both, comprise a plurality of micropores. Helmet cover.

[0146] Embodiment 17: A helmet cover as described in embodiment 16, wherein the plurality of microperforations is applied to less than the entire inner surface of the unitary shell assembly, less than the entire outer surface of the unitary shell assembly, or both.

[0147] Embodiment 18: A helmet cover described in any one of embodiments 16-17, wherein each of the multiple microholes independently has a diameter of about 0.1 μm to 10 μm.

[0148] Embodiment 19: A helmet cover described in any one of embodiments 16-18, wherein each of the plurality of microholes independently has a diameter of about 0.5 μm to 5 μm.

[0149] Embodiment 20: A helmet cover described in any one of embodiments 16-19, wherein each of the plurality of microperforations independently has a diameter of about 1 μm±0.5 μm.

[0150] Embodiment 21: A helmet cover described in any one of embodiments 16-20, wherein the multiple micropores have an average diameter of 0.1 μm to 10 μm.

[0151] Embodiment 22: A helmet cover described in any one of embodiments 16-21, wherein the multiple micropores have an average diameter of 0.5 μm to 5 μm.

[0152] Embodiment 23: A helmet cover described in any one of embodiments 16-22, wherein the plurality of microholes have an average diameter of about 1 μm±0.5 μm.

[0153] Embodiment 24: The plurality of microholes is 3.2e9 to 3.2e5 microholes / cm 2 24. The helmet cover of any one of embodiments 16-23, having a distribution of:

[0154] Embodiment 25: The plurality of micropores is 1.3e8 to 1.3e6 micropores / cm 2 25. The helmet cover of any one of embodiments 16-24, having a distribution of:

[0155] Embodiment 26: The plurality of micropores is about 3.2e7 micropores / cm 2 26. The helmet cover of any one of embodiments 16-25, having a distribution of:

[0156] Embodiment 27: A helmet cover described in any one of embodiments 1-26, wherein the one-piece shell assembly has a thickness of 0.25 mm to 4 mm.

[0157] Embodiment 28: A helmet cover described in any one of embodiments 1-27, wherein the one-piece shell assembly has a thickness of approximately 1 mm ± 0.75 mm.

[0158] Embodiment 29: A helmet cover described in any one of embodiments 1-28, wherein the one-piece shell assembly has a thickness of approximately 1 mm ± 0.1 mm.

[0159] (Enumerated embodiments for the method of manufacturing a helmet cover) Embodiment 30: A method of manufacturing a helmet cover, the method comprising: A. providing a polymer injection unit, the polymer injection unit comprising: (i) a barrel mounted screw assembly, the barrel mounted screw assembly including a screw mounted within a barrel; (ii) a processing space, the processing space including a distal end and a proximal end; (iii) one or more nozzles in fluid communication with the processing space, the one or more nozzles being disposed at a distal end of the processing space; With B. providing an injection mold tool, the injection mold tool including a mold cavity in fluid communication with a nozzle, the injection mold tool constructed to form a one-piece helmet cover; C. introducing a polymeric material into the treatment space; D. melting the polymeric material in the processing space, the melting being accomplished by mixing the polymeric material using a screw mounted within the barrel, applying a heat source to bring the polymeric material to a first predetermined temperature and creating a predetermined back pressure; E. injecting a volume of polymeric material into the mold cavity through one or more nozzles, the volume of polymeric material being sufficient to fill the mold cavity; F. cooling the polymeric material within the mold cavity to a second predetermined temperature; G. Extracting the polymer material in the mold cavity from the injection mold tool and providing a helmet cover; A method comprising:

[0160] Embodiment 31: The method described in embodiment 30, wherein the helmet cover has the features described in any one of embodiments 1-29.

[0161] Embodiment 32: The method of any one of embodiments 30-31, wherein the method of manufacturing a helmet cover further comprises providing micro-apertures on the helmet cover.

[0162] Embodiment 33: The method of embodiment 32, wherein the microperforations are applied to less than the entire inner surface of the unitary shell assembly, less than the entire outer surface of the unitary shell assembly, or both.

[0163] Embodiment 34: The method of any one of embodiments 32-33, wherein each of the micropores independently has a diameter of 0.1 μm to 10 μm.

[0164] Embodiment 35: The method of any one of embodiments 32-34, wherein each of the micropores independently has a diameter of between 0.5 μm and 5 μm.

[0165] Embodiment 36: The method of any one of embodiments 32-35, wherein each of the micropores independently has a diameter of about 1 μm±0.5 μm.

[0166] Embodiment 37: The method of any one of embodiments 32-36, wherein the micropores have an average diameter of 0.1 μm to 10 μm.

[0167] Embodiment 38: The method of any one of embodiments 32-37, wherein the micropores have an average diameter of 0.5 μm to 5 μm.

[0168] Embodiment 39: The method of any one of embodiments 32-38, wherein the micropores have an average diameter of about 1 μm±0.5 μm.

[0169] Embodiment 40: Micropores are 3.2e9 to 3.2e5 micropores / cm 2 The method of any one of embodiments 32-39, wherein the distribution is:

[0170] Embodiment 41: Micropores are 1.3e8 to 1.3e6 micropores / cm 2 The method of any one of embodiments 32-40, wherein the distribution is:

[0171] Embodiment 42: The micropores are about 3.2e7 micropores / cm 2 The method of any one of embodiments 32-41, wherein the distribution is:

[0172] Embodiment 43: A method according to any one of embodiments 30-42, wherein the method for manufacturing a helmet cover comprises melting a polymeric material in a treatment space by bringing the material to a first predetermined temperature.

[0173] Embodiment 44: The method of embodiment 43, wherein the first predetermined temperature is 230±30° C.

[0174] Embodiment 45: The method of any one of embodiments 43-44, wherein the first predetermined temperature is 230±20° C.

[0175] Embodiment 46: The method of any one of embodiments 43-45, wherein the first predetermined temperature is 230±15° C.

[0176] Embodiment 47: The method of any one of embodiments 43-46, wherein the first predetermined temperature is 230±5° C.

[0177] Embodiment 48: The method for manufacturing a helmet cover according to any one of embodiments 30-47, comprising generating a predetermined back pressure while melting a polymer material in a processing space.

[0178] Embodiment 49: The method of embodiment 48, wherein the predetermined backpressure is less than about 20 bar.

[0179] Embodiment 50: The method of any one of embodiments 48-49, wherein the predetermined backpressure is less than about 15 bar.

[0180] Embodiment 51: The method of any one of embodiments 48-50, wherein the predetermined backpressure is about 5±1 bar.

[0181] Embodiment 52: The method of any one of embodiments 30-51, wherein the method of producing a helmet cover includes cooling the polymeric material in the mold cavity to a second predetermined temperature.

[0182] Embodiment 53: The method described in embodiment 52, wherein the second predetermined temperature is 60±10° C.

[0183] Embodiment 54: The method described in any one of embodiments 52-53, wherein the second predetermined temperature is 60±8°C.

[0184] Embodiment 55: The method described in any one of embodiments 52-54, wherein the second predetermined temperature is 60±6° C.

[0185] Embodiment 56: The method described in any one of embodiments 52-55, wherein the second predetermined temperature is 60±4° C.

[0186] Embodiment 57: The method described in any one of embodiments 52-56, wherein the second predetermined temperature is 60±2°C.

[0187] Embodiment 58: The method of any one of embodiments 30-57, wherein the method of manufacturing a helmet cover comprises injecting a volume of polymeric material.

[0188] Embodiment 59: The method of embodiment 58, wherein injecting the volume of polymeric material is accomplished by applying a first progressive pressure gradient.

[0189] Embodiment 60: The method of embodiment 59, wherein the progressive pressure gradient is from about 80 bar to about 10 bar.

[0190] Embodiment 61: The method of any one of embodiments 59-60, wherein the progressive pressure gradient is from about 70 bar to about 15 bar.

[0191] Embodiment 62: The method of any one of embodiments 58-61, wherein injecting the volume of polymeric material occurs within 20±20 seconds.

[0192] Embodiment 63: The method of any one of embodiments 52-62, wherein cooling the polymeric material in the mold cavity occurs within 60±20 seconds.

[0193] Embodiment 64: The method of any one of embodiments 58-63, wherein the steps of introducing a polymeric material into the processing space, melting the polymeric material in the processing space, injecting a volume of the polymeric material into the mold cavity through one or more nozzles, and cooling the polymeric material in the mold cavity occur within 130±40 seconds.

[0194] Embodiment 65: The method of any one of embodiments 58-64, wherein injecting a volume of polymeric material into the mold cavity through one or more nozzles further comprises holding the mold cavity at a holding pressure when the mold cavity is about 90-99% filled by volume.

[0195] Embodiment 66: The method of any one of embodiments 58-65, wherein injecting a volume of polymeric material into the mold cavity through one or more nozzles further comprises holding the mold cavity at a holding pressure when the mold cavity is about 95-99% filled by volume.

[0196] Embodiment 67: The method of any one of embodiments 58-66, wherein injecting a volume of polymeric material into the mold cavity through one or more nozzles further comprises holding the mold cavity at a holding pressure when the mold cavity is about 99% by volume filled.

[0197] Embodiment 68: The method of any one of embodiments 65-67, wherein the holding pressure is 100±10 bar.

[0198] Embodiment 69: The method of any one of embodiments 30-68, wherein the polymeric material comprises a thermoplastic as described in any one of embodiments 7-13.

[0199] Embodiment 70: The method of any one of embodiments 30-69, wherein the polymeric material comprises a thermoplastic of any one of embodiments 7-13 and one or more additives of any one of embodiments 14-15.

[0200] (Example) Example 1 The following table provides an exemplary commercially available helmet 102 over which a helmet cover 100 can be placed. [Table 1-1] [Table 1-2] [Table 1-3]

[0201] Example 2 The following description provides an example process specification for a method of manufacturing the helmet cover 100 via injection molding. The total cycle time for the injection molding method 600 using the example process specification is about 130 seconds. [Table 2]

[0202] Example 3 The following table provides exemplary specifications for a polymeric material (TPU95) for use in the method of manufacturing a helmet cover 100 via injection molding. [Table 3]

Claims

1. A method for manufacturing a helmet cover, the method comprising: A. Providing a polymer injection unit, said polymer injection unit comprising: (i) a barrel mounted screw assembly, the barrel mounted screw assembly comprising a screw mounted within a barrel; (ii) a processing space, the processing space having a distal end and a proximal end; (iii) one or more nozzles in fluid communication with the processing space, the one or more nozzles being disposed at the distal end of the processing space; and B. providing an injection mold tool, said injection mold tool comprising a mold cavity in fluid communication with said one or more nozzles, said injection mold tool constructed to form said helmet cover in one piece; C. introducing a polymeric material into the treatment space; D. melting the polymeric material within the processing space, the melting being accomplished by mixing the polymeric material using the screw mounted within the barrel and applying a heat source to bring the polymeric material to a first predetermined temperature and create a predetermined back pressure; E. injecting a volume of said polymeric material through said one or more nozzles into said mold cavity, said volume of said polymeric material being sufficient to fill said mold cavity; F. cooling the polymeric material within the mold cavity to a second predetermined temperature; G. Extracting the polymeric material within the mold cavity from the injection mold tool to provide the helmet cover. A method comprising:

2. The method of claim 1, wherein the polymeric material is thermoplastic polyurethane (TPU).

3. The method of claim 1, wherein the polymeric material is selected from the group consisting of at least TPU 90, TPU 95, or a mixture thereof.

4. The method of claim 1, wherein the polymeric material is TPU.

5. The method of claim 4, wherein the polymeric material comprises one or more additives, the one or more additives being selected from the group consisting of color pigments, finishing surface chemicals, utility additives, and mixtures thereof.

6. The method described in claim 1, wherein the helmet cover has a thickness of 1±0.1 mm.

7. The method of claim 1, wherein the form cavity is formed to provide micro-holes on the helmet cover.

8. The method of claim 1, wherein the method of manufacturing the helmet cover further comprises providing micro-holes on the helmet cover via a mechanical process or a laser drilling process after extracting the polymeric material in the form cavity from the form.

9. The method of claim 1, wherein the mold cavity is formed to provide micropores on the helmet cover, the micropores having diameters of 1 μm and 0.5 μm.

10. The method of claim 1, wherein the first predetermined temperature is 230±3°C.

11. The method of claim 1, wherein the predetermined back pressure is 5±1 bar.

12. The method of claim 1, wherein the second predetermined temperature is 60±2°C.

13. The method of claim 1, wherein injecting the volume of polymer material is accomplished by applying a first progressive pressure gradient, the progressive pressure gradient being from 70 bar to 15 bar.

14. The method of claim 1, wherein injecting a volume of the polymeric material occurs within 20±5 seconds.

15. The method of claim 1, wherein cooling the polymeric material within the formwork cavity occurs within 60±5 seconds.

16. The method of claim 1, wherein the steps of introducing the polymeric material into the processing space, melting the polymeric material within the processing space, injecting a volume of the polymeric material into the formwork cavity through one or more nozzles, and cooling the polymeric material within the formwork cavity occur within 130±20 seconds.

17. The method of claim 1, wherein injecting the volume of the polymeric material into the formwork cavity through the one or more nozzles further comprises holding the formwork cavity at a holding pressure of 100 bar when the formwork cavity is 99% by volume filled.

18. Providing an injection form tool comprises: Obtaining a helmet geometry file by scanning a helmet; Modifying the helmet geometry file to form a helmet cover geometry file; Printing a three-dimensional helmet cover prototype; Adjusting the helmet cover geometry file; generating the injection mold tool using the helmet cover geometry file; Further comprising: Modifying the helmet geometry file includes one or more of: manipulating a size of the helmet cover, manipulating a shape of the helmet cover, modifying a structure of the helmet cover, adding one or more gripping members to the helmet cover, adding a plurality of micro-holes to the helmet cover, or a combination thereof; The method of claim 1 , wherein adjusting the helmet cover geometry file includes providing an improved fit of a helmet cover compared to the three-dimensional helmet cover prototype.

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