Patent Application
20240101230
The invention relates to a board for sport equipment. The invention further relates to a method of manufacturing a board for sport equipment.
Most boards are built one at a time. Typically, the manufacture process of a board includes forming a foam core in the shape of the board by cutting and sanding, covering the shaped core with fiberglass and resin to form a hard outer shell of the board, carefully sanding the board to remove any excess resin. Such as boards require of few weeks to be produced. Other disadvantage includes the amount of waste produced by the current manufacturing solutions.
Furthermore, protective bumpers for sport equipment are generally provided for nose, tail and/or rail of the board. Such protective bumper usually comprises a piece of plastic which is either screwed or glued on the nose, tail or rear side of the board. These bumpers however have numerous disadvantages, especially for the users as these bumpers tend to become detach from the board.
The present application and the proposals herein seek to address one or more of the problems noted above and/or seek to provide improved manufacture method of boards for sport equipment especially in connection with protective bumpers.
In one aspect, the present disclosure relates to a method of manufacturing a board for sport equipment, the method comprising the steps of molding a substrate on a first mold; transferring the substrate to a second mold; and injecting a material into a cavity provided between at least a part of an edge side of the substrate and the second mold to form the board with a board bumper on the at least a part of the edge side of the substrate. By overmolding the material to the edge of the substrate, the material is molded onto the board bumper directly on the edge of the substrate providing a rigid assembly of mating parts, thereby improving the quality and performance of the board. Furthermore, overmolding reduce labor cost and time since the need for extra fasteners or adhesives for maintain the board bumper attached to the substrate is avoided. For instance, rather than produce two separate parts made from different materials and assemble them manually using glue or screws, overmolding enables you to create a single part from multiple materials seamlessly. The need for fewer steps has a knock-on effect on production costs, and the overmolding process is considered a highly cost-effective injection molding process.
According to an embodiment of the present disclosure, the method further comprises the step of encompassing, when forming the board with the board bumper, a protrusion formed at the edge side surface of the substrate by the bumper. Traditionally, this protrusion (or extension) need to be cut and/or sanded to obtain a smooth side surface of the board, which requires time and precision to stop before over-sanding the surface, since over-sanding will require to discard the board resulting on waste of material. In the present method, cutting and/or sanding is not required because the protrusion will be within the board bumper, thereby reducing time, man cost and waste material during manufacturing.
Optionally, the material comprises a thermoplastic or a thermosetting plastic. Thermoplastics are plastics that become moldable at a certain temperature and solidifies upon cooling, allowing them to be recyclable. Examples of thermoplastics include thermoplastic polyurethane (TPU), polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polytetrafluoroethylene (PTFE). Thermosetting plastic (also known as thermosets) are plastics that cannot be molded again, allowing them to be resistant to high temperatures. Examples of thermosetting plastics include epoxy, polyester, and thermoset urethane.
According to an embodiment of the present disclosure, molding the substrate on the first mold comprises one of a resin transfer molding (RTM) process, vacuum assisted RTM (VARTM) process, and light RTM process. By using closed mold manufacturing like RTM, VARTM or Light RTM, fewer steps are needed in manufacturing a board since after demolding the surface of the substrate no longer needs additional finishing steps like sanding and polishing.
According to an embodiment of the present disclosure, molding the substrate on the first mold comprises placing a shaped core sandwiched between a first layer and a second layer of fiber cloth in the first mold; introducing a resin into the first mold; and bonding the resin to the first and second layers of fiber cloth by curing to form the substrate. Traditionally, handmade substrates (also called boards) requires of pouring and evenly spreading a resin, known as a laminating resin, over a fiber cloth layer in order to form a hard surface around the shaped core when the resin is cured. Since pouring and evenly spreading has to be perform on both sides of the shaped core, a handmade substrate requires of few weeks to manufacture. In the present invention, the shaped core is placed into a mold where a layer of fiber cloth on top and bottom surfaces of the shaped core and resin are bonded. Curing the resin causes the fiber cloth layers to bond with the resin, thereby providing hard surface (i.e. a fiber-reinforced plastic) around the shaped core faster than handmade substrates. For example, heating the first mold and resin reduces the time required to introduce the resin and the time required for curing within a matter of minutes instead of hours or days. Furthermore, after curing, fiber-reinforced plastic extend from top surface and bottom surface of the shaped core about a corresponding end. Usually, these extensions need to be sanded and polished to obtain a smooth side surface of the board. In the present method, this is not needed because the extensions will be within or inside the board bumper, thereby reducing time and man cost during production.
According to an embodiment of the present disclosure, the method further comprises the step of forming the protrusion (or extension) by coming together the first layer and second layer of fiber cloth at the edge side surface of the substrate and bonding using the resin. Typically, the fiber cloth layer is bigger in size than corresponding top/bottom surface of the shaped core, and such ‘laps’ are wrapped around the side surface of the substrate when resin is spread on the fiber cloth. Thus, after laminating, for example, the top surface of the shaped core, it is necessary to cure, cut and sand the overlapping areas of the wrapped around lap before being able to laminate an opposite side of the shaped core, for example, the bottom surface. Thereby, increasing the time of manufacture. In the present invention, this wrapping, curing, cutting and sanding step is not needed as these ‘laps’ (protrusions, extensions) are encapsulated by the bumper, which allows to reduce the time of manufacture.
Optionally, the shaped core comprises a foam of at least one of polyurethane (PU), polystyrene (PS), polyethylene (PE) and polyethylene terephthalate (PET). Optionally, the fiber cloth comprises at least one of fiberglass, carbon fiber, aramid fiber and natural plant fiber. Optionally, the resin comprises epoxy or polyester.
According to an embodiment of the present disclosure, the second mold has a profile defining the cavity. The profile in the second mold allows not only to provide a board which is protected from impacts, but also to enable a variety of boards to be made merely by selecting second molds of different profiles.
According to an embodiment of the present disclosure, the method further comprises the step of: selecting at least one portion of the second mold defining a part of the profile of the second mold based on intended behavior properties of the board. This mold can be used without change over the years in the production of skateboards. When a new skateboard model is desired, a simple and inexpensive mold may be obtained to produce bumpers of new shapes to be used with the original central two-piece platform.
In another aspect, the present disclosure relates to a board for sport equipment comprising: a substrate having a first surface, a second surface opposite to the first surface and a side surface connecting the first surface and the second surface; and a board bumper molded on at least a part of the side surface of the substrate.
According to an embodiment of the present disclosure, the substrate comprises a shaped core placed in between a first layer and a second layer of fiber cloth and bounded to the layers by a resin.
According to an embodiment of the present disclosure, the substrate comprises a shaped core placed in between a first layer and a second layer of fiber cloth and bounded to the layers by a resin.
According to an embodiment of the present disclosure, the board bumper has a shape selectable based on intended behavior properties of the board.
The invention will be described further with respect to embodiments shown in the drawings.
The following is a description of certain embodiments of the invention, given by way of example only and with reference to the figures. It is also to be understood that the terminology used herein is for the purpose of describing particular aspects only and is not intended to be limiting. Coordinate axes in the x, y and z direction are shown in each figure to assist in the explanation of the relative arrangement of features of the board.
In the context of the present application, “board for sport equipment” means any board suitable for any sport that is played with a board as main equipment, for example skateboards, surfboards, stand-up paddleboards, wind surfboards, kneeboards, kiteboards, and the like.
The board 10 comprises a substrate 20 having a first surface 22, a second surface 24 opposite to the first surface 22 and a side surface 26 connecting the first surface 22 and the second surface 24. For example, the first surface can be a top surface and the second surface can be a bottom or rear surface. Boards are usually defined by its parts including a nose—the front tip of the board—, a tail—the back part of the board—and a rail—part of the side surface of the board. When boards are in use, the nose and tail tend to break due cracks, delamination, buckling, and the like. For example, surfboards tend to crack due to impacting rocks and/or surfers or surfboards. As another example, skateboards tend to delaminate after the nose, tail and/or sides heavily impact curbs or other obstacles. Moreover, skateboards tend to experience a wear which may eventually create a sharp tail or edge on the tail area (also known as razor tail) due to scraping of the tail on a hard surface. This razor tail can leave nasty cuts and cause injuries.
The substrate 20 comprises a shaped core 40 placed in between a first layer 42 and a second layer 44 of fiber cloth and bounded to the layers by a resin. When the resin is cured, both layers of fiber cloth impregnated with the resin become hard, and form a fiber-reinforced plastic around the shaped core, which allows the shaped core to be water resistant while increasing the strength of the shaped core. As shown in
In the context of the present application, “shaped core” refers to a core which has been previously manufactured into the shape of the board. For example, the shaped core can be manufactured by means of molding where foamable material in provided into a mold cavity having a shape corresponding to that of the board, or by means of manual shaping where a shaper cuts and sands raw material into the shaped core, or by means of any combination of them. The shaped core is manufactured into a shape according to any particular desired style to provide a top side (deck) and an under side (bottom) of the board. Alternatively, the shaped core can be previously manufactured into the shape of the board by means of computing numerical control.
Optionally, the shaped core 40 comprises a foam. Cores made of foam provide lightweight boards due to the low density of foam. The foam can be made of at least one of polyurethane (PU), polyethylene (PE), polystyrene (PS), and polyethylene terephthalate (PET).
Polyurethane (PU) is a thermoset material, meaning that it can withstand very high temperatures. This means that a polyurethane shaped core will no longer melt when heat is applied. Furthermore, polyurethane (PU) is easy to shape due to its very fine and stiff composition.
Polyethylene (PE) is a thermoplastic material, meaning that it t has a low melting point. This means that a polyethylene shaped core can be recycled, melted down and reformed into another shape. Thus, polyethylene is environmentally friendly as waste leftover from the cores can be recycled. Furthermore, polyethylene cores are resistant to water, moisture, and chemicals, and extremely durable due to its High impact resistance.
Polystyrene (PS) is also a thermoplastic material. Furthermore, polystyrene is easier to shape than polyethylene. However, polyethylene (PE) is more lightweight and stronger than polystyrene (PS), thus polyethylene can endure high impact while being less heavy and dense than polystyrene. Polystyrene and polyethylene cores are not as durable as polyurethane cores but usually have a higher density. Examples of polystyrene includes extruded polystyrene (XPS) and expanded polystyrene (EPS).
Shaped cores comprising foam of at least one of polyurethane (PU), polyethylene (PE) and polystyrene (PS) may not provide the strength to resist breakage required for the corresponding sport. Hence, shaped banks can be strengthen by covering its top side and under side with a fiber cloth with provide high break resistance when a resin impregnating the fiber cloths is cured.
Optionally, the fiber cloth comprises at least one of fiberglass, carbon fiber, aramid fiber and natural plant fiber. As the names imply, fiberglass is made of small strands of glass that have been melted down, while carbon fiber is made of small strands of carbon atoms. Each of the fiber cloths can then be combined with a resin to create a stiff product (e.g., a fiber-reinforced plastic) that can fit any mold. Further, fiber-reinforced plastics last a long time, are weatherproof and can be colored, shiny or dull. Fiberglass is light, less stiff and less brittle than carbon fiber. In addition to being higher in tensile strength, carbon fiber is also higher in price compared to fiberglass.
Optionally, the resin comprises epoxy or polyester. Epoxy has low shrinkage during cure and good adhesion to all types of fiber cloths.
The board 10 also comprises a board bumper 30 molded on at least a part of the side surface 26 of the substrate 20. For example, the board bumper 30 can be molded on the nose of the substrate 20 to protect the nose, and/or on the tail of the substrate 20 to protect the tail, and/or on the rail of the substrate 20 to protect the rail. Optionally, the board bumper 30 has a shape selectable based on intended behavior properties of the board. The intended behavior properties may refer to any characteristic required by the board with board bumper in an specific situation. Some examples of the shape of the board bumper in relation with the intended behavior properties of the board are given in
In the example of
In an initial step 101, the method comprises molding a substrate 20 on a first mold. The first mold may have a first mold cavity having a shape corresponding to that of the substrate 20. For example, the first mold may include a top portion and a bottom portion that when engaged define the first mold cavity, and when a moldable material is provided into the first mold cavity, the moldable material is molded into the substrate.
Optionally, the molding of the substrate on the first mold can comprise one of a resin transfer molding (RTM) process, vacuum assisted RTM (VARTM) process, and light RTM process. Resin transfer molding (RTM) is a closed molding method in which a pre-formed material (which can be sandwiched between fiber-reinforced layers) is placed between a two-part mold. Once, the two parts of the mold are set to close, resin is pumped under pressure through injection channels into the mold, where it cures under heat and pressure. Vacuum assisted RTM (VARTM) is a variation of RTM in which a top portion of the mold has been replaced with a vacuum bag which assist in resin flow through the mold. The VARTM process involves the use of a vacuum to facilitate resin flow into the fiber layup contained within the mold covered by the vacuum bag. After the impregnation occurs, the composite is allowed to cure at room temperature. Light RTM is also a variation of RTM in which the closed mold consists of an “A” side mold (base mold) and a semi-rigid “B” side mold (counter mold) that is sealed to the “A” side mold using vacuum pressure. Resin is drawn into the resulting cavity under vacuum. After the impregnation occurs, the composite is allowed to cure before demolding. The semi-rigid “B” mold retains a small amount of flexibility, enabling the “B” mold to fit perfectly with the “A” mold.
Optionally, the step 101 can comprise various steps, as step 102, 103 and 104 defined hereinafter. In step 102, the method comprises placing a shaped core 40 between a first layer 42 and a second layer 44 of fiber cloth in the first mold. For example, in case the first mold may include a top portion and a bottom portion that when engaged define the first mold cavity, the first layer 42 is placed on a surface of the bottom portion defining part of the first mold cavity, the shaped core 40 is then placed over the first layer 42 and, finally the second layer 44 is placed on a surface of the shaped core 40 opposite to the first layer 42. Afterwards, the top portion of the mold is engaged to the bottom portion by, for example, clamps.
In step 103, the method comprises injecting a resin into the first mold to form the substrate 4040, and in step 104, the method comprises bonding the resin to the first layer 42 and the second layer 44 of fiber cloth by curing. Optionally, the bonding may comprise heat pressing the resin to the shaped core 40.
Although, the shaped core 40 has been manufactured by inject molding as described in steps 102, 103 and 104, it should be understood that the shaped back 40 of the invention can be manufactured by any other technique such as compression molding, casting, and the like.
As shown in
The second mold has a profile defining the cavity. This cavity defines the shape of the board bumper. Thus, a substrate 20 can be manufactured with different board bumpers depending on the profile of the second mold. For example, a board which may be highly damaged on the nose due to intended use can be manufactured using a second mold where the cavity corresponding to the nose board bumper is big.
Optionally, in step 106, the method comprises selecting at least one portion of the second mold defining a part of the profile of the second mold based on intended behavior properties of the board. The intended behavior properties of the board may comprise properties of the board that make the board short or long, wide or narrow, different shape of nose, tail and rails board bumpers according to the intended use of the board. For example, a skateboard with a board bumper intended to be used by a kid or unexperienced skater may require of extra rail board bumpers to protect the rail of the board and/or aesthetical impressions on the bottom surface (e.g. the second surface 24) of the substrate compared to an experienced skater.
In step 107, the method comprises injecting a material into a cavity provided between at least a part of an edge side of the substrate and the second mold to form the board with a board bumper on the at least a part of the edge side of the substrate.
Optionally, the material can be a thermoplastic or a thermosetting plastic. For example, the thermoplastic material can be thermoplastic polyurethane (TPU), polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polytetrafluoroethylene (PTFE). comprises polyurethane, polyethylene, polypropylene, and the like. For example, the thermosetting material can be epoxy, polyester, and thermoset urethane.
While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.
