Patent Description:
Fiber-reinforced plastics (FRP), also called fiber-reinforced polymers, for example carbon fiber-reinforced plastics (CFRP) are widely used materials for lightweight structures, ranging from sports equipment, to automotive components, to aircraft structures. A method for manufacturing of FRP's comprises depositing fiber tows, for example preimpregnated tows, for example tapes, onto a substrate. The depositing is, for example, done by a robot, for example a manipulator comprising a tape dispensing end effector for additive manufacturing. Depositing tapes imposes constraints on one or more of: the speed at which the tape is deposited, the trajectories described by the depositing end effector, the radius of curvature of the trajectories, the amount of adhesive polymer used, the amount of air trapped in the FRP, the fiber volume fraction inside the FRP, the deposition process temperature, the polymer's viscosity, the deposited layer's geometry, for example defined by its dimensions (for example defined by one or more of its length, width, and height), and the interleaving, juxtaposition, and superposition patterns of tapes, for example tape layers. There is therefore a need for fiber tows, for example preimpregnated tows, that enable their deposition at greater speed and greater homogeneity than can be achieved using conventional tape-laying techniques. There is a need to lay fiber tows over trajectories that comprise curves with small radii of curvature, and with improved and diversified fiber layout patterning capabilities. There is also a need for layouts, forming methods, and deposition methods for such tows. Such tows and related methods may, for example, increase the strength and quality of manufacturing fiber-reinforced polymer parts while reducing their cost.

Document <CIT> discloses the preamble of claim <NUM>.

A problem in the field fiber-reinforced plastics relates to the speed at which one or more fiber rovings can be deposited to form a layout. Another problem relates to the precision of the layout. A further problem relates to the density of fibers within a given volume that can be achieved to confer strength to the resulting composite material. It is therefore an object of this disclosure to provide embodiments of preformed material rovings and roving assemblies, for example formed from fiber tows, as solutions to the problems of forming fiber-reinforced polymer parts at high speed, precision, fiber density, and strength. It is also an object of this disclosure to provide methods to form embodiments of preformed material rovings and roving assemblies from the fiber tows.

A method according to the present invention includes the features of claim <NUM>.

One embodiment of the present disclosure is created by providing a preformed material for use in fiber-reinforced composite materials, the preformed material comprising one or more fiber rovings comprising parallel fibers wherein the fiber rovings comprise one or more folds in a direction parallel to the direction of the fibers and wherein the unfolded width of the fiber rovings have a width comprised in a range from <NUM> to <NUM>.

For example, in the embodiment of the preformed material, the fiber rovings comprising one or more folds are selected from the group consisting of a one-fold roving, a gate-folded, a partly overlapping two-fold roving, a fully overlapping two-fold roving, an accordion fold roving, a double parallel-folded roving, and a gate-folded roving that comprises four folds. For example, the preformed material comprises one or more parallel paths or tracks of fiber rovings. For example, the preformed material comprises separate one or more fiber rovings that are parallel to each other. For example, one or more fiber rovings that comprise only one fold comprise a fold that is located about halfway of the unfolded width of the roving. For example, one or more fiber rovings that comprise only two folds comprise a first fold and a second fold that are at about equal distance from the roving's half-width point. For example, a cross-sectional cut through the preformed material orthogonally to the direction of the fibers of one or more of the one or more fiber rovings comprises one or more visible rovings comprising one or more folds.

In some embodiments of the preformed material, the fiber density by volume is comprised in a range from <NUM>% to <NUM>% of fibers. In some embodiments of the preformed material, the thickness of a fiber roving is comprised in a range from <NUM> to <NUM>. In some embodiments of the preformed material, the fiber density by volume within the cross-sectional area defined by the external contour of a fiber roving is comprised in a range from <NUM>% to <NUM>% of fibers. In some embodiments, the preformed material comprises one or more layers comprising one or more of the fiber rovings, each layer comprising an arrangement of adjacent and parallel fiber rovings. In some embodiments, the preformed material comprises one or more stacked layers comprising one or more of the fiber rovings, each layer comprising an arrangement of adjacent and parallel fiber rovings.

For example, the fiber rovings comprise from <NUM> to <NUM> fibers. For example, the fiber rovings have a width in a range from <NUM> to <NUM>. For example, the fiber rovings comprise one or more fibers selected from the group consisting of carbon fibers, glass fibers, polyaramide fibers, rayon fibers, acrylic fibers, polypropylene fibers, polyamide fibers, polyester fibers, polyetheretherketone fibers, silicon carbide fibers, alumina fibers, and alumina-silica fibers. For example, one or more of the fiber rovings comprises a thermoplastic polymer that forms a first bond within the one or more folds and a second bond between a first fiber roving and a second adjacent fiber roving.

In some embodiments of the preformed material, one or more layers comprising one or more pluralities of adjacent fiber rovings comprising two or more of the fiber rovings are sandwiched between two or more layers of a thermoplastic polymer. In some embodiments, the preformed material comprises one or more beams comprising one or more of the fiber rovings. In some embodiments, one or more of the fiber rovings follows a portion of an external contour of the preformed material. In some embodiments of the preformed material, a first end of a roving faces the second end of a roving. In some embodiments, the preformed material comprises a first roving and a second roving wherein, in a portion where the first roving is parallel and adjacent to the second roving, the first end of the first roving faces the second end of the first roving at a first facing location and the second end of the second roving faces the second end of the second roving at a second facing location and wherein the second facing location is offset with respect to the first facing location along the length of the first roving.

<FIG> presents an image acquired with, for example, an optical microscope of a cross-sectional cut <NUM> of a preformed material <NUM> for use in fiber-reinforced composite materials. For example, the preformed material <NUM> comprises one or more fiber rovings that comprise one or more fibers selected from the group consisting of carbon fibers, glass fibers, polyaramide fibers, rayon fibers, acrylic fibers, polypropylene fibers, polyamide fibers, polyester fibers, polyetheretherketone fibers, silicon carbide fibers, alumina fibers, and alumina-silica fibers. The cross-sectional cut <NUM> is, for example, formed by cutting the preformed material orthogonally to one or more fiber tows or rovings <NUM> comprised in it. A method for acquiring an image of a cross-section comprises, for example, the steps of: i) forming a preformed material <NUM> comprising one or more rovings <NUM>, for example rovings comprising a polymer, for example a thermoplastic polymer; ii) cutting the preformed material orthogonally to one or more fiber rovings <NUM> to form a cross-section <NUM>; iii) grinding the exposed cross-section <NUM>; and iv) polishing the exposed cross section <NUM>. <FIG> is a replica of <FIG> wherein, for illustrative purposes, the cross-section <NUM> of a plurality of rovings <NUM> is marked. For a visualization example, the approximate thickness midline <NUM> of each roving's cross-section is marked by a black line. The approximate scale of the image is shown with a white bar, the length of which is about <NUM>. For example, the preformed material <NUM> has a fiber density comprised in a range from <NUM>% to <NUM>% of fibers by volume, for example from <NUM>% to <NUM>% of fibers by volume, for example from <NUM>% to <NUM>% of fibers by volume. For example, wherein the fiber density within the cross-sectional area defined by the contour of a roving is comprised in a range from <NUM>% to <NUM>% of fibers by volume, for example from <NUM>% to <NUM>% of fibers by volume.

The embodiment of a preformed material <NUM> shown in <FIG> comprises one or more rovings <NUM> that comprise one or more folds 1100F in a direction parallel to the direction of the fibers comprised in the respective roving <NUM>. For example, a roving is a tow of fibers that are packed together, for example forming a roving having an approximately rectangular cross-section, for example in the form of a folded unidirectional tape of fibers having, in its unfolded tape configuration 1100TP shown in <FIG>, a first face FA1 and a second face FA2. For example, the tape material that is used to form the one or more rovings <NUM> is a unidirectional preimpregnated tape 1100TP of fibers <NUM>, also called "pre-preg", for example comprising a polymer, for example as a polymer adhesive, for example an epoxy resin, for example a thermoplastic polymer. In the rest of the description a polymer represents one or more adhesive materials, for example a polymer adhesive, for example one or more resins, for example an epoxy resin, for example a thermoplastic polymer.

For example, a fold 1100F describes a <NUM>° fold wherein a portion of a face of a roving is brought into contact or brought to face another portion of the face of the roving. For example, a roving comprising one or more folds is a roving wherein one or more portions of a face of a roving is brought into contact or brought to face another portion of one or more of the first face and the second face of the roving. For example, the first face and the second face of the roving are bonded to each other by a bond 1100B1 of thermoplastic polymer, for example a thermoplastic polymer comprised in the roving. For example, the embodiment <NUM> of <FIG> shows rovings <NUM> comprising one or two folds 1100F. In <FIG>, for illustrative purposes, the folds are indicated for a few selected rovings only and the lead lines point to a fold 1100F illustrated along the roving's midline <NUM>. In practice, a fold can also be visualized or materialized by the shape, for example the convex curvature, of the external contour 1100E of a roving. For example, <FIG> highlights <NUM> rovings <NUM> comprising folds photographed in the preformed material <NUM>. Six of the rovings comprise one fold 1100F. Six of the rovings comprise two folds 1100F.

A certain set of rovings comprising one or more folds 1100F and having a certain folded width 1100W present, for example, one or more useful improvements. For example, the speed at which the roving can be drawn to a specified position, for example by an additive manufacturing robot, is greater than with an unfolded roving.

The embodiment of a preformed material <NUM> shown in <FIG> comprises a plurality of folded rovings arranged in rows or layers <NUM> wherein, for example, a first roving comprises a portion of a face that is collinear with a portion of a face of a second roving on the row. For example, a plurality of folded rovings arranged in rows <NUM> are adjacent to each other. For example, a plurality of folded rovings arranged in rows <NUM> are parallel to each other. For example, one or more rovings <NUM> form one or more turns (for example U-turns 1100U, for example interwoven U-turns 1100U) and loops to form parallel paths of rovings, as shown in <FIG>. For example, a plurality of folded rovings are arranged in rows <NUM> that are adjacent and parallel to each other. The embodiment of a preformed material <NUM> shown in <FIG> comprises a plurality of folded rovings arranged in columns <NUM> wherein, for example, a first roving comprises a portion of a face that is stacked onto and parallel with a portion of a face of a second roving on the column. For example, the embodiment of a preformed material <NUM> shown in <FIG> comprises a plurality of folded rovings arranged in rows <NUM> and stacked in columns <NUM>, in effect forming a rectangular square-packed lattice of folded rovings. Other regular arrangements are possible, for example an arrangement wherein the stacked rows present an offset with respect to each other, for example in the X-direction. For example, the offset from row-to-row has a constant increment. For example, the offset from row-to-row has an increment that is equal to about half the width, for example in the X-direction, of a folded roving, in effect forming a preformed material <NUM> comprising an embodiment <NUM> comprising a hexagonal-packed lattice of folded rovings, as shown in the embodiment of <FIG>. In some embodiments of a preformed material <NUM> comprising an offset of the stacking in one or more directions, the one or more arrangement gaps introduced by the offset are, for example, filled in with one or more of polymer <NUM> and roving material, for example one or more folded rovings <NUM>.

In <FIG>, for purpose of visualization, the external contour 1100E of two selected rovings <NUM> is marked with a black line enveloping the roving. In <FIG>, the external contour of one or more rovings is readily visualizable or detectable because at least a portion of the folded roving is separated from an adjacent roving by a visible layer of polymer <NUM>. In some embodiments, the polymer originates from the polymer that, for example, preimpregnates the rovings <NUM> or the tape 1100TP used to form the roving <NUM> prior to their assembly into the preformed material <NUM>. In other embodiments, the polymer is added upon bonding of the roving as part of a method <NUM> for forming the preformed material <NUM>. In further embodiments, the polymer is added as a layer prior to bonding the roving <NUM> to the preformed material <NUM> as part of a method <NUM> for forming the preformed material <NUM>.

<FIG> shows a perspective view of a tape 1100TP comprising a plurality of fibers <NUM>, for example parallel fibers. The tape 1100TP has, for example, a rectangular cross-section. For example, the tape 1100TP is a "pre-preg", for example preimpregnated with a polymer.

<FIG> shows a perspective view of a folded roving <NUM>. The folded roving <NUM> is, for example, formed by folding a tape 1100TP parallel to the direction of the fibers comprised in the roving <NUM>. The roving <NUM> comprises a plurality of fibers <NUM>, for example parallel fibers. <FIG> is not necessarily at the same scale as <FIG>. The midline <NUM> into the thickness of the roving <NUM> is represented, as shown in <FIG> and <FIG>.

In <FIG>, the width 1100W of the folded rovings <NUM> comprised in the preformed material <NUM> is, for example, in a range from about <NUM> to about <NUM>, for example from about <NUM> to about <NUM>. For example, the width 1100W of a folded roving comprised in an embodiment of a preformed material <NUM> is comprised in a range from about <NUM> to about <NUM>, for example from about <NUM> to about <NUM>. For example, the developed length of the midline <NUM> characterizing the width 1100TW of the unfolded roving tape 1100TP used to form the rovings is about <NUM>. For example, the width 1100TW of the unfolded roving tape 1100TP is comprised in a range from about <NUM> to about <NUM>, for example from about <NUM> to about <NUM>. For example, the thickness <NUM> of a folded roving <NUM> comprised in an embodiment of a preformed material <NUM> is comprised in a range from about <NUM> to about <NUM>, for example from about <NUM> to about <NUM>, for example from about <NUM> to about <NUM>. For example, the rovings comprise from about <NUM> fibers to about <NUM>,<NUM> fibers, for example from about <NUM> fibers to about <NUM> fibers.

<FIG> present different embodiments of folded rovings <NUM>. The embodiments <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> are represented by the midline <NUM> of the folded roving's cross-section. The folded rovings <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> comprise one or more folds 1110F that are formed in a longitudinal direction of the folded roving <NUM>. In the rest of this description, the words roving and folded roving are used to represent a roving that comprises one or more folds. For generality, the number <NUM> is used to represent the different embodiments of folded rovings. In a folded roving <NUM>, the one or more folds 1110F are, for example, formed parallel to the direction of the fibers comprised in the roving <NUM>. For example, the rovings <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> are formed by one or more rolls and dies, for example as part of one or more of a roll-forming method and a pultrusion method that comprises passing a tape 1100TP through one or more rolls and dies.

For example, <FIG> presents a one-fold roving <NUM> comprising only one first fold <NUM>. The fold 1100F, <NUM> is, for example, formed halfway along the length of the midline <NUM> of the roving tape used to form the folded roving <NUM>. For example, the fold 1100F is located about halfway of the unfolded width 1100TW of the roving <NUM>. In some embodiments of one-fold rovings <NUM>, the first fold <NUM> is formed at a position that is shorter or longer that the halfway of the length of the midline <NUM>. A roving comprises, for example, one or more of a first fold <NUM> and a second fold <NUM>.

<FIG> present various embodiments of two-fold rovings <NUM>, <NUM>, <NUM>, <NUM>. For example, <FIG> presents a gate-folded roving <NUM>. An embodiment of a gate-folded roving <NUM> comprises, for example, a first fold <NUM> and a second fold <NUM>. In the gate-folded roving <NUM> of <FIG> the first flap <NUM> formed by the first fold <NUM> and the second flap <NUM> formed by the second fold <NUM> meet, for example, at about half the length of the midline <NUM>. For example, some embodiments of two-fold rovings comprise a first fold <NUM> and a second fold <NUM> that are at about equal distance from the roving's half-width point 1100HW. For example, <FIG> presents a partly overlapping two-fold roving <NUM>, for example wherein the first flap <NUM> partly overlaps a first face of the tape and partly overlaps the second flap <NUM>. <FIG> presents a fully overlapping two-fold roving <NUM>, for example comprising a letter fold, for example wherein the first flap <NUM> completely overlaps the second flap <NUM>. <FIG> presents a version of an accordion fold roving <NUM>, for example wherein the first flap <NUM> is folded over a first face FA1 and the second flap <NUM> is folded over a second face FA2.

<FIG> present various embodiments of rovings comprising more than two folds. For example, <FIG> presents a double parallel-folded roving <NUM> that comprises three folds <NUM>, <NUM>, <NUM> along its width. The double parallel-folded roving <NUM> is, for example, formed by a method wherein a one-fold roving <NUM> comprising a fold <NUM> is folded a second time against itself to form folds <NUM> and <NUM>. <FIG> present two variants <NUM> and <NUM> of a gate-folded roving that comprise four folds <NUM>, <NUM>, <NUM>, <NUM>. For example, the first variant of a gate-folded roving <NUM> and the second variant of a gate-folded roving <NUM> comprise two folds at each side of the roving's width. For example, a method to form the first variant of a gate-folded roving <NUM> comprises the steps of: i) forming a gate-folded roving <NUM> comprising the step of folding a first flap <NUM> delimited by a first fold <NUM> onto a first face of the roving and folding, for example simultaneously, a second flap <NUM> delimited by a second fold <NUM> onto the first face of the roving; and ii) folding the first flap <NUM> one or more times onto, for example, the first face, and folding the second flap <NUM> one or more times onto, for example, the first face. The first variant <NUM> comprises, for example, a fully overlapping two-fold at each side of the width of the roving. <FIG> presents, for example, a double-gate fold roving <NUM> comprising, as in the gate-folded roving <NUM>, a first fold <NUM> and a second fold <NUM> and, between the first and second folds, a third fold <NUM>.

<FIG> presents a perspective view of a sandwiched embodiment <NUM> showing a cross-sectional cut <NUM> of a preformed material <NUM> for use in fiber-reinforced composite materials, for example as a beam or part of a beam. For example, the sandwiched embodiment comprises one or more layers <NUM> of rovings comprising one or more pluralities of adjacent rovings <NUM> that are sandwiched between two or more layers of a polymer <NUM>, <NUM>, for example a thermoplastic polymer. Each layer <NUM> comprises one or more rovings <NUM> that comprise one or more folds 1100F, for example one or more rovings selected, for example, from one or more of the folded rovings <NUM>. In some embodiments of the preformed material <NUM>, for example the sandwiched embodiment <NUM>, the embodiment comprises one or more external polymer layers <NUM>, for example located at one or more peripheral faces of the embodiment <NUM>, <NUM>, <NUM>, for example cylindrically surrounding the embodiment <NUM>, <NUM>, <NUM>, for example enveloping the embodiment <NUM>, <NUM>, <NUM>.

<FIG> present respectively a top view into the X-Y plane and a side view into the Y-Z plane, for example, of a first layout of an embodiment <NUM> of a preformed material <NUM>. For example, the first layout embodiment <NUM> is representative of a cross-section through a preformed material <NUM>. For example, the first layout <NUM> comprises one or more layers <NUM> comprising rovings <NUM>, for example rovings comprising one or more folds <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>.

For example, the first layout comprises one or more rovings <NUM>, <NUM> that follow a portion of an external contour 5000E of the preformed material <NUM>, for example of the first layout <NUM>, for example as a track <NUM>. In some embodiments, a track <NUM> comprises, for example, a column of rovings <NUM> (<FIG>), for example extending in the Z-direction. Another embodiment for a track <NUM> comprises, for example, a stack of rovings <NUM>, for example arranged as a lattice, as shown in <FIG>. Returning to the embodiment of <FIG>, the first layout <NUM> comprises, for example, <NUM> parallel roving tracks <NUM> in the X-Y plane, each comprising one or more rovings <NUM>. Other embodiments of the first layout <NUM> comprise, for example, fewer or more parallel roving tracks <NUM>, for example comprised between zero and <NUM>, for example <NUM>. For example, the tracks <NUM> are concentric. In an alternative embodiment <NUM> (<FIG>), the tracks <NUM> comprise one or more tracks <NUM> arranged in a spiral. For example, as shown in <FIG>, an embodiment of the first layout <NUM> comprises parallel roving tracks <NUM> along the entirety of the external contour 5000E. For a further example, as shown in <FIG>, an embodiment <NUM> of the first layout <NUM> comprises parallel roving tracks <NUM> along one or more first faces or sides of the external contour 5000E but not along other one or more second faces or sides of the external contour 5000E.

For example, a first end or head <NUM> of a roving <NUM> faces, for example contacts, the second end or tail 1100T of a roving <NUM>. For example, a first end or head <NUM> of a roving <NUM> faces the second end or tail 1100T of a roving <NUM> at a facing location 1100HT, for example along an external contour 5000E of an embodiment of a preformed material <NUM>. For example, the facing location 1100HT-<NUM> of a first roving <NUM>-<NUM> is offset along the length of the first roving <NUM>-<NUM> from the facing location 1100HT-<NUM> of a second roving <NUM>-<NUM> that is parallel, for example adjacent, to the first roving <NUM>-<NUM>. For example, the facing location 1100HT-<NUM> of a first roving <NUM>-<NUM> and the facing location 1100HT-<NUM> of a second roving <NUM>-<NUM> form a staggered arrangement <NUM>, for example a staircase arrangement. For example, a staggered arrangement <NUM> comprises a first roving <NUM>-<NUM> and a second roving <NUM>-<NUM> wherein, in a portion where the first roving <NUM>-<NUM> is parallel and adjacent to the second roving <NUM>-<NUM>, the first end <NUM> of the first roving <NUM>-<NUM> faces the second end 1100T of the first roving <NUM>-<NUM> at a first facing location 1100HT-<NUM> and the second end <NUM> of the second roving <NUM>-<NUM> faces the second end 1100T of the second roving <NUM>-<NUM> at a second facing location 1100HT-<NUM> and wherein the second facing location 1100HT-<NUM> is offset with respect to the first facing location 1100HT-<NUM> along the length of the first roving <NUM>-<NUM>. For example, in some embodiments, the offset distance is comprised in a range from <NUM> to <NUM>. For example, the rovings <NUM> are arranged in a staggered arrangement in more than one plane. For example, <FIG> presents a first staggered arrangement <NUM> in the X-Y plane and <FIG> presents a second staggered arrangement <NUM> in the Y-Z plane. <FIG> further shows examples of sections 1A1, 1A2, 1A3 that correspond, for example, to the cross-sections presented in <FIG>.

<FIG> present an internal region <NUM>, also called an infill <NUM>, that fills the area or volume, for example in a plurality of stacked rows or layers <NUM>, comprised within the external contour 5000E of the preformed material <NUM>. For example, in <FIG>, the infill <NUM> is, for example, completely surrounded by roving tracks <NUM>. In <FIG>, the infill <NUM> is, for example, partially surrounded by roving tracks <NUM>, for example along one or more sides of the infill <NUM>, for example along one or more sides and a portion of a side of the infill <NUM>. For example, the infill <NUM> comprises separate fiber rovings <NUM> that are parallel to each other.

<FIG> further presents an embodiment of the preformed material <NUM> that comprises fillings <NUM>, for example comprising a polymer material, wherein no rovings <NUM> are present. For example, a method <NUM> for forming portions of a preformed material (block diagram in <FIG>) comprises the steps: i) forming <NUM> one or more layers <NUM>, for example a stack of layouts <NUM>; ii) adding <NUM> one or more fillings <NUM>, for example as an addition of one or more polymers; and iii) compressing <NUM> the material <NUM>, for example within a mold.

<FIG> presents a side view into the Y-Z plane, for example, of a first layout of an embodiment <NUM> of the preformed material <NUM> of <FIG>, presents a side view wherein the rovings <NUM> present a staggered arrangement 5100Z within the thickness of the preformed material <NUM>, for example through two or more layers <NUM> in the Z-direction, for example as depicted, in the Y-Z plane. For example, an embodiment of a preformed material comprises a set of rovings <NUM> forming a first staggered arrangement <NUM> in a first plane, for example the X-Y plane, and a second staggered arrangement 5100Z in a second plane, for example the Y-Z plane.

<FIG> presents an embodiment for a second layout <NUM> as an alternative or a complement to the first layout <NUM> embodiment presented in <FIG>. The second layout comprises tracks <NUM> each comprising one or more rovings <NUM>. For example, in <FIG> each track <NUM> comprises <NUM> rovings <NUM> in a head-to-tail arrangement. In the second layout <NUM>, for example, the head <NUM> of a first roving <NUM> of a first track <NUM> joins, for example connects to, for example overlaps, the tail 1100T of a second roving. For example, the head <NUM> to tail 1100T arrangement is repeated over a portion or the entirety of the external contour 5000E of the preformed material <NUM>. For example, the second layout <NUM> presents a method to form a layer <NUM> that complements the first layout with additional rovings at selected regions of the external contours.

<FIG> presents an embodiment for a third layout <NUM> as an alternative or complement to the first layout <NUM> embodiment presented in <FIG>. In the third layout, the one or more roving <NUM> of the one or more track <NUM> is comprised on a portion of the external contour 5000E. For example, a portion of the external contour 5000E comprises rovings <NUM> of the infill <NUM> that intersect or contact the external contour 5000E, for example orthogonally to the portion of the external contour 5000E. For example, one or more roving <NUM> of the track <NUM> is parallel to one or more roving of the infill <NUM>. For example, the third layout <NUM> presents a method to increase the strength along a selected direction within a selected region of a preformed material, for example a region defined as a layer <NUM> that is comprised, for example comprised within a stack of layers <NUM>, within the first layout <NUM>. For example, an embodiment of the preformed material <NUM> comprises one or more stacked layers <NUM>, for example formed from a layout <NUM>, <NUM>, <NUM>, <NUM> of fiber rovings <NUM>, each layer <NUM> comprising an arrangement of adjacent and parallel fiber rovings <NUM>. For example, an embodiment of the preformed material <NUM> comprises one or more planar surface, for example a surface in the X-Y plane of the one or more layout <NUM>, <NUM>, <NUM>, <NUM>, for example formed from one or more layout <NUM>, <NUM>, <NUM>, <NUM>. For example, an embodiment of the preformed material <NUM> is formed as a beam <NUM>, <NUM>. For example, an embodiment of the preformed material <NUM> comprises one or more beam <NUM>, <NUM>, for example formed from one or more layout <NUM>, <NUM>, <NUM>, <NUM>.

<FIG> presents an embodiment for a fourth layout <NUM>, for example as an alternative or complement to the first layout <NUM> embodiment presented in <FIG>, wherein one or more track <NUM> is arranged in a spiral <NUM>. For example, the fourth layout <NUM> comprises one or more roving to form a track <NUM> arranged in a spiral <NUM>. For example, a method to increase the speed at which a robot forms a preformed material <NUM> by laying rovings <NUM>, for example the one or more roving <NUM> of the one or more track <NUM>, for example in comparison to the concentric tracks <NUM> of the first layout <NUM>, comprises depositing one or more roving <NUM> to form a spiral <NUM>. For example, an embodiment of a preformed material <NUM> comprises one or more layer <NUM> according to one or more of the first, the second, the third, and the fourth layout embodiments <NUM>, <NUM>, <NUM>, <NUM>, respectively.

<FIG> present perspective views of a folded roving <NUM>, 1100C1, 1100C2, 1100C3 embodiment comprising an additional polymer <NUM>, for example between one or more of the first fold <NUM> and the second fold <NUM>, for example between one or more of the first flap <NUM> and the second flap <NUM>. <FIG> presents, for example, a first embodiment of a folded roving 1100C1 comprising one or more polymers <NUM> enclosed within a roving folded as, for example, a gate-folded roving. The roving of <FIG> comprises, for example, a rounded rectangular cross-section of first width 1100W1, for example a square cross-section. The first width 1100W1 has, for example, a width in a range from <NUM> to <NUM>, for example from <NUM> to <NUM>, for example from <NUM> to <NUM>, for example <NUM>. For example, a width of the polymer <NUM> is in a range from <NUM> to <NUM>. For example, the polymer <NUM> is formed as a continuous line along the length of the roving 1100C1. In some embodiments, the polymer <NUM> is formed, for example, as a dashed line along the length of the roving 1100C1.

<FIG> presents a second embodiment of a folded roving 1100C2 comprising polymer <NUM> enclosed within a roving folded as, for example, a gate-folded roving. The second embodiment 1100C2 is, for example, formed as a variation of the first embodiment 1100C1 with a second width 1100W2 wherein the second width 1100W2, although comprised in the same ranges as that of the first width 1100W1 is greater than that of 1100W1. For example, a portion of polymer <NUM> is comprised in a channel 1100CH between a first end and a second end of the width 1100TW of the tape 1100TP used to form the folded roving <NUM>, 1100C1, 1100C2, 1100C3. A method to form the second embodiment of a folded roving 1100C2 comprising polymer <NUM> comprises, for example, the steps of: i) supplying the first embodiment of a folded roving 1100C1 comprising polymer <NUM>; and ii) pressing the first embodiment 1100C1 in one or more directions, for example the Z-direction. For example, the pressing comprises a step, for example simultaneous to pressing, of adding heat to the roving 1100C1, for example to melt the polymer <NUM> comprised within it. For example, the pressing is comprised in a pultrusion method. For example, the pressing comprises applying pressure in the Z-direction, for example with one or more of: a shoe, for example a hot shoe; and a roller, for example a hot roller. For example, the channel 1100CH provides a method to enable excess polymer to escape from within the enclosure formed by the folded roving 1100C1, 1100C2 when the roving is pressed. For example, the pressing is simultaneous to the depositing of the folded roving 1100C1, 1100C2, 1100C3 during forming of the preformed material <NUM>. For example, the pressing occurs at the location where the folded roving 1100C1, 1100C2, 1100C3 contacts one or more of: a substrate onto which the preformed material <NUM> is formed; and the preformed material <NUM>, for example previously deposited folded rovings <NUM> comprised in the preformed material <NUM>. In some embodiments of the second folded roving 1100C2, pressing the folded roving causes polymer <NUM> to diffuse between the fibers <NUM> of the roving <NUM>, for example as part of a method for forming a folded roving <NUM> that has a fiber density that is lower than that of the tape 1100TP.

<FIG> presents a third embodiment of a folded roving 1100C3 comprising one or more polymers <NUM> enclosed within a roving folded as, for example, a gate-folded roving. The third embodiment 1100C3 is, for example, formed as a variation of one or more of the first embodiment 1100C1 and the second embodiment 1100C2 with a third width 1100W3 wherein the third width 1100W3, although comprised in about the same ranges as that of the first width 1100W1 is, for example as a result of pressing, greater than that of 1100W1. In some of the third embodiments, the third width 1100W3 is greater than that of the second width 1100W2. A method to form the third embodiment of a folded roving 1100C3 comprising one or more polymers <NUM> comprises, for example, supplying an embodiment of a folded roving 1100C1, 1100C2 comprising one or more polymers <NUM> and pressing the embodiment 1100C1, 1100C2 in one or more directions, for example the Z-direction. For example, forming the third embodiment of a folded roving 1100C3 comprises supplying heat to the folded roving 1100C1, 1100C2, for example as for forming the second embodiment of a folded roving 1100C2. In some embodiments of the third folded roving 1100C3, pressing the folded roving causes polymer <NUM> to diffuse between the fibers <NUM> of the roving <NUM>, for example forming a folded roving <NUM> that, within the volume that encloses its fibers, comprises a greater polymer content than that of the tape 1100TP. In some embodiments 1100C1, 1100C2, 1100C3 of the folded roving comprising one or more polymers <NUM>, the gas content is lower than that of the tape 1100TP used to form the folded roving <NUM>. In some embodiments 1100C1, 1100C2, 1100C3 of the folded roving comprising one or more polymers <NUM>, the polymer content is lower than that of the tape 1100TP used to form the folded roving <NUM>.

For example, the method of forming the folded roving <NUM>, 1100C1, 1100C2, 1100C3 causes one or more of gases and excess polymer to be pressed out of the tape 1100TP used to form the folded roving. For example, the method of forming the folded roving <NUM>, 1100C1, 1100C2, 1100C3 comprises forming rovings comprising two or more proportions of polymer. For example, the method of forming the folded roving <NUM>, 1100C1, 1100C2, 1100C3 comprises forming rovings comprising two or more spatial distributions of polymer across, for example, the cross-section of the roving, for example along one or more of the X-direction and the Z-direction. For example, the method of forming the folded roving <NUM>, 1100C1, 1100C2, 1100C3 comprises forming rovings comprising two or more proportions of polymer along the length of the folded roving, for example in the Y-direction.

<FIG> presents a cross-sectional view of an embodiment <NUM> of a preformed material <NUM> comprising a plurality of embodiments of folded rovings 1100C2, 1100C3 comprising a polymer <NUM> enclosed within a folded roving. For example, the embodiment <NUM> comprises a first plurality (for example comprising a plurality of rovings 1100C2) of a first folded roving 1100C2 embodiment comprising a first proportion of polymer <NUM> and a second plurality (for example comprising a plurality of rovings 1100C3) of a second folded roving 1100C3 embodiment comprising a second proportion of polymer <NUM>. For example, the embodiment <NUM> comprises embodiments of a first folded roving comprising a first spatial distribution of polymer <NUM> and embodiments of a second folded roving comprising a second spatial distribution of polymer <NUM>. For example, the embodiment <NUM> of a preformed material <NUM> comprises a plurality of the second embodiment of a folded roving 1100C2 comprising polymer <NUM> and a plurality of the third embodiment of a folded roving 1100C3 comprising polymer <NUM>. For example, the embodiment <NUM> of a preformed material <NUM> comprises alternating columns (or rows) <NUM>-<NUM>, <NUM>-<NUM>, each column (or row) comprising a first folded roving embodiment 1100C2 and a second folded embodiment 1100C3, respectively. For example, the embodiment <NUM> of a preformed material <NUM> comprises a first region <NUM>-<NUM> comprising a first folded roving embodiment 1100C2 and a second region <NUM>-<NUM> comprising a second folded roving embodiment 1100C3.

For example, the embodiment <NUM> of a preformed material <NUM> comprises a first region <NUM>-<NUM> comprising a first proportion of one or more folded roving embodiments 1100C1, 1100C2, 1100C3, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> and a second region <NUM>-<NUM> comprising a second folded roving embodiment 1100C3 comprising a second proportion of one or more folded roving embodiments <NUM>, for example folded roving embodiment 1100C1, 1100C2, 1100C3, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. For example, the embodiment <NUM> of a preformed material <NUM> comprises one or more second regions <NUM>-<NUM> at the periphery of the preformed material <NUM> that have one or more of a different fiber density, a different proportion of polymer <NUM>, and a different spatial distribution of polymer <NUM> than that of one or more first regions <NUM>-<NUM> located closer to the geometric center of the preformed material <NUM> than the second regions <NUM>-<NUM>. For example, in some embodiments of the preformed material <NUM> the one or more first regions <NUM>-<NUM> are surrounded, for example along one or more axes, X, Y, and Z, by one or more second regions <NUM>-<NUM>. For example, in some embodiments of the preformed material <NUM> the one or more first regions <NUM>-<NUM> comprising first folded roving embodiments 1100C2 having a first fiber density are surrounded by second regions <NUM>-<NUM> comprising second folded roving embodiments 1100C2 having a second fiber density that is greater than the first fiber density. The fiber density is, for example, a density by volume. For example, for an embodiment of a preformed material <NUM> comprised of one or more polymers and fibers, the fiber density of the second regions <NUM>-<NUM> is greater in a range from <NUM>% to <NUM>%, for example in a range from <NUM>% to <NUM>%, than the density of the first regions <NUM>-<NUM>. Some embodiments of a preformed material <NUM> comprise, for example, other materials, for example a foam, for example a polystyrene foam, and the density of the second regions <NUM>-<NUM> is greater than ten times that of the first regions <NUM>-<NUM>. For example, an embodiment of a preformed material <NUM> is formed as a sandwich wherein one or more first regions <NUM>-<NUM> are sandwiched between two or more second regions <NUM>-<NUM>.

<FIG> presents a block diagram of a method <NUM> to form a preformed material <NUM>. In some embodiments of the method <NUM>, the method comprises, for example, a step <NUM> of depositing one or more polymers <NUM> onto a fiber roving <NUM>, for example a tape 1100TP that comprises fibers <NUM>. The polymer <NUM> is deposited, for example, on one or more faces FA1, FA2 of the tape 1100TP.

The method <NUM> comprises, for example, a step <NUM> of folding the roving <NUM>, for example folding the tape 1100TP, into one or more of a folded roving embodiment <NUM>, 1100C1, 1100C2, 1100C3, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. For example, in an embodiment of the method <NUM> to form a preformed material <NUM> that comprises a step <NUM> of depositing a polymer <NUM>, the step of depositing <NUM> and the step of folding <NUM> occur simultaneously.

The method <NUM> comprises, for example, a step <NUM> of pressing the roving <NUM>. For example, the step of pressing <NUM> the roving comprises positioning a portion of the roving onto a substrate or onto a portion of the preformed material <NUM>. The step of pressing <NUM> comprises, for example, pressing the roving in one or more directions, for example the Z-direction. For example, the pressing <NUM> comprises adding heat to the roving, for example to melt the polymer comprised at one or more of: a location adjacent to the roving, for example on the substrate; a location on the roving, for example at one or more of the roving's surfaces; and within the roving. For example, the pressing <NUM> is simultaneous to a pultrusion process applied to the roving. For example, the pressing <NUM> comprises applying pressure in the Z-direction, for example with one or more of: a shoe, for example a hot shoe; and a roller, for example a hot roller.

The method <NUM> comprises, for example, a step <NUM> of cutting the roving <NUM>. For example, the step of cutting <NUM> the roving comprises one or more of: a transverse cut, for example in a direction orthogonal to that of the fibers <NUM> comprised in the roving <NUM>; a bevel cut; and a circular cut, for example comprising a circular motion around the roving's fibers. In some embodiments of the method <NUM>, following the cut, the deposited remaining end of the roving, for example the roving's tail 1100T, is, for example, subjected to a further pressing step <NUM>. Subsequently, the other end of the roving <NUM> is, for example a roving's head <NUM>. The roving's head <NUM> is positioned to another location, for example one or more of adjacent to and superimposed onto, a previously deposited roving <NUM>, and the sequence of steps comprising one or more of i) depositing <NUM>, ii) folding <NUM>, iii) pressing <NUM>, and iv) cutting <NUM> is repeated or continued. In some embodiments of the method <NUM> for forming a preformed material, one or more of the steps <NUM>, <NUM>, <NUM>, <NUM> occur simultaneously, for example at different locations along the length of the roving <NUM>. For example, the thermoplastic polymer comprised in the tape 1100TP contributes to form i) one or more first bonds 1100B1 within the one or more folds <NUM>, <NUM>, <NUM>, <NUM> of the rovings <NUM>; and ii) one or more second bonds 1100B2 between a first roving <NUM> and a second adjacent roving <NUM> (<FIG> and <FIG>).

<FIG> present cross-sections of embodiments of a preformed material <NUM>, for example comprising one or more preformed materials <NUM>. <FIG> presents the cross-section of a rectangular beam <NUM>, for example formed from one or more preformed material embodiments <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. <FIG> presents the cross-section of an I-beam <NUM>, for example comprising a first preformed material <NUM> shaped as a first T-beam bonded to a second preformed material <NUM> shaped as a second T-beam. For example, a first preformed material <NUM> and a second preformed material <NUM> have a same cross-section. <FIG> presents the cross-section of a channel beam <NUM>. For example, the channel of the channel beam <NUM> is formed from one or more planar preformed material embodiments <NUM>. For example, the preformed material embodiment <NUM> comprises a rectangular cross section, for example the preformed material embodiments <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, onto which a first rectangular beam <NUM> is added or formed as a first side pillar <NUM> of the channel and a second rectangular beam <NUM> is added or formed as a second side pillar <NUM> of the channel. For example, the side pillars <NUM>, <NUM> are formed as continuation steps in an additive manufacturing process comprising forming a stack of folded rovings, each stack comprising a plurality of folded rovings <NUM>.

For example, an embodiment of a preformed material <NUM> comprises one or more folded rovings <NUM> and one or more tapes 1100TP. For example, an embodiment of a layout <NUM>, <NUM>, <NUM>, <NUM> comprises one or more folded rovings <NUM> and one or more tapes 1100TP. For example, the one or more folded rovings <NUM> and the one or more tapes 1100TP are positioned parallel to each other. For example, the one or more folded rovings <NUM> and the one or more tapes 1100TP comprise a portion of their length that is parallel to each other.

It has been found that embodiments of a preformed material <NUM> formed from one or more folded roving embodiments <NUM>, 1100C1, 1100C2, 1100C3, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> are formed with greater speed and with more precise control and repeatability of structural characteristics and material strength than embodiments formed from one or more of unfolded fiber tapes 1100TP and fiber filaments having a circular cross-section. It is believed that one or more factors associated with the folded rovings <NUM> and their aforementioned cross-sectional dimensions contribute improvements. For example, the method <NUM> comprising folding <NUM> and pressing <NUM> the tapes 1100TP contributes to reducing the number and size of voids, for example voids comprising gas or excess polymer initially comprised within the unprocessed tapes 1100TP. For example, it has been found that a preformed material <NUM> comprising folded rovings <NUM> has less than <NUM>% of void content in regions where the folded rovings form curved paths. For example, it has been found that a preformed material <NUM> comprising folded rovings <NUM> has less than <NUM>% of void content in regions where the folded rovings form straight paths. For example, it has been found that a preformed material <NUM> comprising folded rovings <NUM> and having undergone a compression molding stage comprises a void content in the range of <NUM>% to <NUM>%.

It has been found that a preformed material that is, for example, manufactured from fiber filaments comprising a circular cross section, suffers from the same internal excess of gas and polymer as a preformed material manufactured from unidirectional tapes 1100TP but with the additional inconvenient of additional thickness which requires greater heat addition and greater heating time to reduce the voids within one or more of the filament and the resulting preformed material.

Furthermore, it has been found experimentally that folded rovings can be deposited faster and form paths of smaller radii of curvature than tapes 1100TP or filaments having a circular cross section. For example, the radius of curvature of a continuous path (without kinks or folds) taken by a roving <NUM> comprising from <NUM> to <NUM> fibers, for example from <NUM> to <NUM> fibers, is as small as <NUM>, for example <NUM>. It is believed that the smaller cross-sectional dimensions of the folded rovings <NUM>, the more even heat distribution within the folded rovings <NUM>, and the rounded external geometry at the location the folds 1110F, <NUM>, <NUM> contributes greater flexibility and swiveling, possibly assisted by intra-fold sliding or rearrangement, and ease of self-adjusting upon depositing the folded roving <NUM> than when using tapes with a rectangular cross-section or filaments with a circular or elliptical cross-section.

Claim 1:
A method (<NUM>) for forming a preformed material (<NUM>), the method comprising:
depositing and bonding at least a portion of a fiber roving (<NUM>, 1100C1, 1100C2, 1100C3, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) onto a substrate,
characterised in that
the fiber roving includes parallel fibers (<NUM>) and the fiber roving has one or more folds (1100F, <NUM>, <NUM>, <NUM>, <NUM>) in a direction parallel to the direction of the fibers.