KR20150041019A - Apparatus for composite tape dispensing - Google Patents

Abstract

According to the present invention there is provided an apparatus for applying a resin impregnated tape to a surface of a molding tool, the apparatus comprising an upper frame rotatably mounted on the base frame, wherein the upper frame is mounted thereon A spool retaining assembly for retaining a rotatable spool wound with a resin impregnated tape and a compression roller configured to conform to a surface of the molding tool for pressing the resin impregnated tape onto the surface of the molding tool, , And a tape tensioning system for applying tension to the resin impregnated tape. The base frame includes a tracking system for tracking the surface of the molding tool, the base frame being reciprocally movable relative to the surface of the molding tool.

Description

[0001] APPARATUS FOR COMPOSITE TAPE DISPENSING [0002]

The present invention relates to an apparatus for composite tape dispensing, and more particularly to a device for precisely laying down a prepreg tape. The device may be stacked with prepregs on a molding structure having a contoured surface or a flat surface along a linear or nonlinear path.

In composite technology, resin-impregnated webs or tapes may be used to construct the desired specific components. The prepreg material is comprised of aligned reinforcing fibers (typically carbon, glass or aramid fibers) pre-impregnated with the polymer and used as an intermediate product during molding of the composite structure. Very often, such fibers are arranged in a straight line in a unidirectional structure to form a tape-like product, typically 12 to 60 inches (30.5 to 152.4 cm) wide.

The composite structure may be built up with continuous layers, for example, applied to a working surface such as a molding tool, a mandrel, or any surface used to form the composite part. For example, when constructing a composite wind turbine blade, a wind blade spar or a wing structure from a prepreg tape, a long (i.e., longer than 40 meters) length prepreg tape is stacked on the desired molding tool very precisely . Precise filament alignment is required to obtain the desired composite properties. Also, during laminate construction, uniform compression of the prepreg tape is required to minimize entrapped air, which can cause voids in the cured composite laminate. Very small misalignment of the fiber orientation can cause significant loss of important engineering properties. For example, an orientation deviating from 5 to 10 degrees may result in a composite material loss of 10 to 20%. The voids in the composite may also result in lower composite properties. Pores larger than 2% can cause significant loss of inter-laminar shear strength and can act as damaged growth sites in the composite during its service life.

Composite wind turbine blades are often straight side laminates with varying thicknesses, e.g., thicknesses of about 0.1 inch (0.25 cm) to 1.5 inches (3.81 cm). This is a laid-up mold surface that can range from flatness to varying degrees of concave or convex curvature. For example, a wind blade spar can be flat at the tip and curved at the root. This configuration further increases the complexity of stacking prepreg tapes very precisely. The hand layup of these spas is very difficult, time consuming, and more difficult to ensure precision. An alternative final tool for the hand lay-up involves the use of an automated tape stacking machine. This type of machine has been developed for aerial structures for over 20 years. These machines are designed to stack prepregs extremely precisely, but these machines are very expensive and too complicated for wind turbine blades.

The present invention relates to a device capable of stacking a wide prepreg product for a structure with in-plane curvature while greatly reducing the wrinkling effect on the inner radius.

In one aspect of the invention, there is provided an apparatus for applying a resin impregnated tape to a surface of a molding tool, the apparatus comprising an upper frame rotatably mounted to the base frame, wherein the upper frame is mounted thereon A spool holding assembly rotatable therewith, the spool holding assembly for holding a spool wound with a resin impregnated tape, and a pressing roller configured to match the surface of the molding tool to press the resin impregnated tape onto the surface of the molding tool A compression assembly, and a tape tensioning system for applying tension on the resin impregnated tape. The base frame includes a tracking system for tracking the surface of the molding tool, the base frame being reciprocally movable relative to the surface of the molding tool.

In one embodiment, the spool retaining assembly includes an alignment system for laterally aligning the spool of the prepreg tape against the surface of the molding tool.

In one embodiment, the pressing roller includes a plurality of continuous discs supported on a rotating shaft, and the disc has a larger central hole diameter than the outer diameter of the rotating shaft.

In one embodiment, the upper frame rotates at least 180 degrees on the base frame so as to change the direction of application of the resin impregnated tape onto the surface of the molding tool. The apparatus may further comprise a rotation table coupled to the upper frame and the base frame to allow rotation of the upper frame on the base frame.

In one embodiment, the tape tensioning system includes an actuated disc brake. The disc brake can be operated manually or automatically.

In one embodiment, the molding tool comprises at least one rail, and the tracking system comprises at least two guide rollers engaging the at least one rail.

The surface of the molding tool may include at least one of a convex contour and a concave contour.

In one embodiment, the width of the resin impregnated tape applied to the molding tool is in the range of about 11.5 inches (292 mm) to about 60 inches (152.4 cm).

In another aspect of the present invention, the apparatus further includes a slitter for finely cutting the resin impregnated tape in the longitudinal direction into a plurality of strips, the slitter being mounted on the upper frame and rotating together with the upper frame. The slitter may comprise a plurality of stationary or rotary knives.

In one embodiment, the plurality of strips of resin impregnated tape are uniform. In another embodiment, the width of the plurality of strips of resin impregnated tape is not uniform.

In one embodiment, the apparatus further comprises a plurality of accumulator rollers disposed downstream of the slitter, each accumulator roller being independently adjustable to accumulate or de-accumulate a portion of each strip of resin impregnated tape , And the accumulator roller is mounted on the upper frame so as to be rotatable together with the upper frame.

In one embodiment, the apparatus can be used to control the placement of the resin impregnated tape on the surface of the molding tool, the tension applied by the tension system on the tape, the direction in which the tape is applied to the surface of the molding tool, Lt; RTI ID = 0.0 > and / or < / RTI >

In one aspect of the invention, there is provided a carriage for applying a resin-impregnated web to an outlined surface of a molding tool, the carriage including a top frame mounted on a base frame, A first spool holding assembly for holding a spool wound with a resin impregnated web and a second spool holding assembly for holding a spool on which a scrim material is mounted; A web pressing assembly comprising a pressing roller configured to conform to concave and convex portions of the surface, and a web tensioning system for applying tension on the resin-impregnated web. The base frame includes a plurality of wheels mounted on the base frame for supporting the carriage, the wheels comprising a plurality of wheels engaging the surface of the molding tool to propel the carriage along the contoured surface of the wind- And a tracking system for tracking the surface of the molding tool, the carriage including a tracking system that is reciprocally movable about the contour of the surface of the molding tool.

In one embodiment, the carriage further comprises a nip for coupling a layer of scrim material from the spool of scrim material to the resin-impregnated web prior to squeezing the resin-impregnated web onto the surface of the molding tool.

In the accompanying drawings, like reference numbers designate like parts or configurations.
1 is a perspective view of an apparatus for stacking prepreg tapes according to an embodiment of the present invention.
Figure 2 is a top view of the device of Figure 1;
Figure 3 is a front view of the apparatus of Figure 1 with a spool of prepreg material mounted.
Figure 4 is a side view of the device of Figure 1 with a spool of prepreg material mounted.
5 is a perspective view of one embodiment of an apparatus for stacking prepregs according to an embodiment of the present invention located in a molding tool;
Figure 6 is a front view of the apparatus of Figure 5;
7 is a perspective view of the apparatus of FIG. 5 showing the rotational motion of the upper frame.
8 is a cross-sectional view of an apparatus for stacking prepreg tapes comprising a tape-thin slitting and dispensing assembly in accordance with an embodiment of the present invention.
Figure 9 is a side view of the device of Figure 8;
10 is a plan view of the apparatus of FIG.
11 is an enlarged plan view of the tensioning system of the apparatus of FIG.
Figure 12 is a partial side view of the apparatus of Figure 8 with a spool of prepreg material mounted.
Figure 13 is a perspective view of the tape alignment assembly of the apparatus of Figure 8;
Figure 14 is a bottom view of the tape positioning assembly of the apparatus of Figure 8;
15A is a schematic diagram showing a prepreg tape dispensed using a conventional apparatus in a linear direction.
15B is a schematic view showing a prepreg tape dispensed using a conventional apparatus in a nonlinear direction.
16 is a photograph showing a prepreg tape dispensed using a conventional apparatus on a curved surface.
17 is a perspective view of one embodiment of an apparatus comprising a scrim distribution assembly in accordance with the present invention.

The apparatus of the present invention is useful for forming a composite laminate structure by applying a tape of continuous fibers impregnated with a resinous binder onto the surface of a mold, mandrel or tool. The fibers may be composed of carbon, glass, ceramics, metals, and / or polymers. The resin binder may be a thermosetting or thermoplastic resin.

In one aspect of the present invention, an apparatus is provided for laying out a wide width unidirectional prepreg tape for a structure, particularly a wind turbine blade. The apparatus includes a spool holder for detachably holding a spool of a continuous web of prepreg material having a wide width. The apparatus includes a mechanism for properly positioning the prepreg on the surface of the molding tool. The apparatus also includes a rotatable mountable prepreg tape placement assembly for bi-directional tape placement and compaction.

The width of the prepreg tape product typically ranges from about 11.5 inches (292 mm) to about 60 inches (152.4 cm). In one embodiment, the width of the prepreg tape is about 12 inches (30.5 cm) to about 60 inches (152.4 cm) or about 11.5 inches (292 mm) to about 15.75 inches (400 mm). In general, it is advantageous to use a wider prepreg tape in order to increase the production efficiency by increasing the prepreg tape stacking speed. Due to the apparatus of the present invention, it is possible to further increase the productivity by bi-directional tape laying and squeezing. Applying the prepreg material to the molding tool can be performed in forward and reverse directions.

Referring to Figs. 1 to 3, in one embodiment of the present invention, the prepreg tape stacking apparatus is a carriage 10 including an upper frame 12 rotatably mounted on a base frame 14. Fig. The prepreg spool retaining assembly 16 and the compression assembly 18 are mounted on the upper frame 12. [ The base frame 14 includes a tracking system 20 for precisely positioning the prepreg material on the surface of the molding tool.

The spool retaining assembly 16 includes a spool 22 and a spool support 24 mounted on the spindle 22. The spool support 24 includes a quick-adjustment pin 26 that contacts the inside of the prepreg spool core such that the spool 80 is centered on the spindle 22. The fast- The spool retaining assembly 16 enables rapid prepreg spool replacement and positioning. The spindle 22 is supported at each end by a truss 28 on the upper frame 12.

3, the carriage 10 includes a spool positioning system 30 that includes a disk 32 and a lateral adjustment bracket 34. The spool positioning system 30 includes a disk 32, The spool positioning system 30 controls the lateral position of the spool of prepreg material on the carriage throughout the prepreg dispensing operation. The disk 32 is fixed to the spindle 22. The disc 32 is positioned between the arms of the U-shaped bracket 34. A pad 36, which is coupled to each arm of the bracket 36, contacts the disk 32. Adjustment in a small lateral direction (i.e., perpendicular to the tape application direction) in the prepreg tape alignment, using the positioning knob 31, can be accomplished by laterally moving the bracket 34 during tape distribution as needed have.

The carriage 10 includes a tensioning system 38 for maintaining a suitable level of tension on the prepreg material during dispensing operations. Friction regulator 40 applies pressure to disc 32 and pad 36 within bracket 34 to establish a baseline resistance for rotation of the prepreg roll during dispense operation. This regulator 40 can be operated manually or automatically based on feedback from a tension monitoring sensor (not shown).

The tensioning system 38 includes a spring-loaded arm 42 that measures the tension on the prepreg tape. The force of the spring 44 on the spring-loaded arm 42 also compensates for small variations in force resulting from a change in the diameter of the prepreg from the propulsion of the prepreg distribution carriage 10 and from the spool . In one embodiment (not shown), the tensioning system may further comprise a sensor for tension monitoring or adjustment. A tension roller 47 attached to the lateral bar 46 positions the prepreg tape in the vicinity of the surface of the molding tool to prepare for the pressing step.

The compression assembly 18 serves to compress the prepreg material as the prepreg material is dispensed onto the surface of the molding tool. The compression assembly applies the compression pressure regardless of the twisting and curvature of the molding tool surface. Compression rollers 48 consist of a plurality of thin and heavy continuous discs 50 on the lateral rotational axis 52, the flat sides of which are compressed together. The disk 50 has a central hole diameter larger than the diameter of the rotary shaft 52. [ The disc 50 has a polished face and / or a friction reducing medium on the face of the disc, so that independent movement of each disc is possible. The heavy disk 50 is vertically movable so that the edges of each disk contact the prepreg material to provide compression. To maintain the lateral position of the disk 50 and limit the motion of the disk to rotation about the rotational axis and translation normal to the rotational axis 52, a retaining member 54 on the rotational axis 52 is positioned adjacent to the last disk at each end . A swing away arm 56 of the compression assembly 18 is pivotally mounted on the upper frame 12 at the pivot point 58. The rotational movement of the crimp assembly 18 allows the operator to lift the crimp assembly of the prepreg tape when the crimp assembly is not in use. The compression assembly 18 may optionally include other configurations including a pneumatic shaped roller and a spring or pneumatically loaded "finger" / arm (not shown) have.

Referring to FIG. 4, the prepreg material 82 is wound around the direction changing roller 43 as it is unwound from the spool 80, and is then positioned by the tension roller 47 in the vicinity of the surface of the molding tool. The carriage 10 moves across the surface of the molding tool in the direction indicated by the arrow. The compression assembly 18 is lowered so as to apply the compression pressure so that the compression roller 48 contacts the prepreg tape 82 and presses the prepreg tape 82 against the surface of the molding tool 60. [

5 and 6, the carriage 10 can be moved over the surface 64 of the molding tool 60 by a wheel 70 positioned above each of the four corners of the base frame 14 . The carriage 10 may be self-propelled using, for example, an electric motor (not shown). In one embodiment, the carriage 10 is guided by a rail 62 positioned along the surface of the molding tool 60.

In the illustrated embodiment, the components of the tracking system 20 of the carriage 10 are incorporated into the carriage 10 and coordinated with the shape of the molding tool 60 to ensure proper placement of the prepreg tape. Typically, such tuning focuses on the specific composition of the final composite structure. As an example, the point at which the center line of the wind turbine blade cap contacts the surface of the molding tool 60 can be used as a "key feature ". The tracking system 20 maintains precise positioning of the prepreg distribution carriage relative to the core characteristics. The components of the tracking system 20 are located on the edge of the flat portion 68 of the molding tool on either side of the central recess 66 of the molding tool 60 as shown in Figures 5-7 And may be embedded within the separate guide rails 62 or within the molding tool surface 64.

The tracking system 20 includes at least a pair of guide rollers 72 mounted near at least one of the legs 74 of the base frame 14 of the carriage and near the wheel 70. The pair of guide rollers 72 are spaced apart and engage both sides of the rail 62 and move along the axis of the rail 62. The second pair of guide rollers 72 can be mounted on the second leg 74 on the same side of the base frame adjacent to the second wheel 70. [ The guide roller 72 provides a definitive position of the carriage 10 and provides proper torsion of the carriage 10 which is in mirror image with that of the molding tool 60 and which guides the molding tool 60 To maintain contact of the carriage 10 with respect to the molding tool. The tracking guide roller 72 may also help to eliminate the pull-off of the carriage resulting from the force required to propel the carriage along the molding tool.

In one alternative embodiment, one or more rails are positioned below the molding tool rather than on the surface of the molding tool. In another alternative embodiment, separate rails are not used to guide the carriage. Instead, the molding tool surface itself comprises a core configuration that is tracked by the carriage to ensure proper placement of the prepreg material.

Compression roller 48 applies a compressive force to the prepreg tape by contacting the top surface of the laminate structural composite as the tape is laminated onto the molding tool. The press roller 48 of a plurality of thin and heavy continuous discs 50 can be matched to the contour of the surface of the molding tool 64 and especially when applied to the concave (or convex) To match the concave portion 66 of the molding tool so as to reduce the tendency to be desired. Along with the pressing roller 48, the prepreg tape can be applied to a molding tool surface having a region having a variable degree of concave curvature, a region having a convex curvature of variable degree, and a flat region. The prepreg tape can also be applied along the non-linear path on the molding tool surface.

7, the upper frame 12 is supported by a rotary table 76 which is capable of rotating the prepreg material by 180 degrees without removing the dispensing carriage 10 from the molding tool 60. [ (14). The rotary table 76 allows the prepreg material to pass through the center of the device 10 during dispensing operations. The locking member 78 prevents rotational movement of the upper frame 12 relative to the base frame 14 when engaged and sets the proper position of the prepreg spool for each dispensing direction on the molding tool 60.

The apparatus of the present invention may further comprise means for guiding the prepreg laminate arrangement to ensure controlled fiber alignment. The operation of the carriage assembly 10 may be controlled by a controller (not shown). For example, the carriage may be connected to a controller configured to control the placement of the prepreg tape, the tension on the tape, the direction in which the prepreg tape is applied to the surface of the molding tool, and the rate at which the prepreg tape is stacked.

The carriage assembly 10 may begin with either end of the molding tool 60 and apply a prepreg material tape and may start or stop according to a predetermined ply position. A cutter may be used to automatically cut the fold. In one embodiment, the carriage assembly 10 may include a laser guide (not shown) for determining the fold position.

In one embodiment, the carriage assembly may be removably coupled to the spool loading station.

In another aspect of the present invention there is provided an apparatus comprising a slitter and an accumulator formed from a wide prepreg tape product for a structure having a planar curvature while greatly reducing the effect of wrinkles on the inner diameter The strips of the prepreg material can be stacked and arranged. The initial width of the prepreg tape product may be in the range of about 12 inches (30.5 cm) to about 60 inches (152.4 cm).

When building the composite structure from the prepreg tape, the tapes are usually stacked in a linear direction. Since the tape is unwound from a single spool, the fibers can not be stretched in the stacking process and can not slide relative to each other. As a result, such a prepreg tape can not be laminated in the shape of a curved surface without forming wrinkles or corrugated portions on the inner diameter.

Referring to FIG. 15A, a prepreg tape 200 that is dispensed using conventional equipment in a linear direction has a plurality of aligned reinforcing fibers 202 pre-impregnated with a polymer. When the tape 200 is applied to a flat and linear surface, the tape will be laid smoothly without wrinkles or corrugated portions. Fig. 15B shows a prepreg tape 200 that is distributed in a non-linear curved direction using a conventional apparatus. The tape 200 is laid smoothly along the outer edge 204 of the curved surface. However, along inner edge 206, corrugations 208 are formed.

16 is a photograph of a 7 inch (17.8 cm) wide strip of prepregs stacked with a radius of plane curvature of 130 feet (39.6 meters) using a conventional apparatus. The corrugations and corrugated portions 208 on the inner diameter 206 are clearly shown. These creases create loss of orientation in the fiber direction, leading to loss of composite mechanical properties in these zones. Carbon fiber composites are particularly susceptible to loss of compressive strength due to this loss of fiber orientation.

Referring to Figs. 8-10, another exemplary embodiment of the prepreg tape dispensing apparatus of the present invention is shown. The apparatus includes a moveable carriage 10 that includes a spool retaining assembly 16 for releasably retaining a spool 80 of a continuous web of prepreg material 82 having a wide width. As described above, this embodiment of the carriage 10 includes an upper frame 12 that is rotatably mounted to the base frame 14. The prepreg spool retaining assembly 16 and the compression assembly 18 are mounted to the upper frame 12. [ The base frame 14 includes a tracking system 20 for precisely positioning the prepreg material on the surface of the mounting tool. The carriage assembly 10 includes a rotary table 76 that allows the upper frame 12 to rotate relative to the base frame 14 such that application of the prepreg tape material on the molding tool 60 is in the forward and / Can be performed in the reverse direction.

As the prepreg material tape 82 is unwound from the spool 80, it is advanced to the slitter 90 where the prepreg material tape is finely cut into a plurality of strips 84 of prepreg material. The slitter 90 may include, for example, a plurality of fixed knives 92 or a rotary knife. The number of strips and the width of each strip 84 are determined by the degree of nonlinearity of the surface of the molding tool 60 to which the strip 84 is applied. For example, the strips 84 may be uniform in width or may have different widths to accommodate the non-linear path of the molding tool 60. Although the description of the apparatus herein refers to a molding tool, it will be understood that the prepreg material may be applied to the surface of the mold, the surface of the mandrel, or any other surface used to form the composite structure in the prepreg dispensing operation .

In another embodiment, the strip 84 is finely cut during manufacture of the wide prepreg web before it is wound onto a single spool. Thereafter, the spools 80 of the pre-cut strip are mounted on the spool retaining assembly 16.

The carriage 10 includes a mechanism for taking a different length of each strip 84 resulting from the non-linear path of the molding tool 60. In one embodiment, an accumulator 94 is used. The accumulator 94 includes a plurality of rollers 96 wherein each strip 84 of the prepregs can be independently controlled when it is necessary to handle the excess length of the individual strips resulting from the nonlinear path on the molding tool 60 Extendable and retractable associated rollers. The accumulator rollers 96 maintain the tension within the individual strips 84 so that the individual strips 84 are applied smoothly to the molding tool 60. Expansion and contraction of the roller 96 of the accumulator 94 may be performed by a plurality of actuators 98 coupled to the rollers 96. [ In one embodiment, the actuator 98 includes an air cylinder.

11, the carriage 10 includes a tension system (not shown) including a pneumatically actuated brake pad 100 that applies friction to the disk 32 under programmed control and a brake disk 32 that is secured to the spindle 22 38).

12 and 13, the prepreg material 82 is advanced to the slitter 90 as it is unwound from the spool 80 where the prepreg material is finely divided into a plurality of strips 84 of prepreg material Is cut. The prepreg strips 84 move over the rollers 96 of the accumulators 94 and the path of each strip processes any excess length of the individual strips originating from the nonlinear path on the molding tool 60 to which the strip is applied Lt; / RTI > From the accumulator roller 96, the strip proceeds to a guide roller 102 which positions the strip in the vicinity of the surface of the molding tool. The squeeze roller 48 contacts the prepreg strip 84 and exerts a squeezing pressure to squeeze the prepreg strip 84 against the surface of the molding tool 60. The surface of the molding surface 60 may include concave and / or convex regions and / or flat regions with varying degrees of curvature. The path of the individual prepreg strips 84 on the surface of the molding tool may be nonlinear or curvilinear, but the device 10 may be provided with strips of prepreg layers and / or gaps between the strips on the mold, As shown in Fig.

Figures 12-14 illustrate steps comprising positioning a tape on a molding tool. Before the tape 82 is finely cut into the strip 84, the tape 82 is guided by the threading guide 104 along the tape path shown in Fig. 12, at which time the slitter 90 is in a deactivated state. The tape 82 is clamped or held on the surface of the molding tool 60. The slit 90 is then activated and the carriage 10 begins to move forward (in the direction indicated by the arrow) so that the finely cut portion of the tape (i.e., the strip 84) The tape 82 is pulled until it extends. Thereafter, the tape 84 is laterally cut and the carriage 10 is advanced so as not to be disturbed, so that the tape just stacked can be pulled and discarded. The carriage 10 then moves to the programmed start position for the next layer to be applied and the squeeze roller 48 is lowered to begin bonding the prepreg strip 84 to the molding tool surface 64. At this point, the prepreg strip 84 is aligned by a crowned accumulator roller 96 and a crowned guide roller 102. As the carriage 10 moves from a straight portion of the molding surface 64 to a swept portion or from one sweep radius to another sweep radius, Carriage drive motor 104 to maintain the center of the cross-carriage drive motor 104. [ In this embodiment, the amount of movement is pre-entered into the offset data points into the table within the controller 112. [ This same crossover carriage 106 is used to move the carriage more or less distance when it is needed to track the tape 82 that has fallen off the spool 80 when detected by the web edge sensor 110 do. This is accomplished by providing a certain amount of compensation for the tape 82 that has been moved on the spool 80 during transfer or the tape that is not uniformly wound on the spool 80.

The orientation of the carriage assembly can be controlled by the controller 112. [ For example, the carriage 10 may be configured to hold the prepreg tape 82 or the strip 84, the orientation of the tape or strip, the direction in which the prepreg tape or strip is applied to the surface of the molding tool 60, May be coupled to a controller 112 configured to control the speed at which the stacked layers are disposed.

The carriage assembly 10 may begin with either end of the molding tool 60 and apply prepreg material tape 82 or strip 84 and may start or stop according to a predetermined tape or strip location . A cutter, e.g., an ultrasonic knife (not shown), may be used to automatically cut the tape or strip. In one embodiment, the carriage assembly may include a laser guide to determine a tape or strip fold position.

The prepreg tape material 82 on the spool 80 may have a liner or backing layer attached to the prepreg tape 82. In one embodiment, the lining or support layer of the prepreg material is removed from the lower side of the prepreg web prior to lamination of the individual strips 84 or tapes 82 of the prepreg material, . In one embodiment (not shown), the prepreg material web 82 includes a lining on the top surface of the web that is removed prior to stacking the webs. The carriage assembly may further include means for detecting incomplete removal of the lining or support from the prepreg material web.

In one embodiment, the carriage assembly 10 may be removably coupled to the spool loading station.

17, another exemplary embodiment of the prepreg tape dispensing apparatus of the present invention is shown. The apparatus includes a scrim distribution assembly 210 that includes a spindle 212 supported at each end by mounting brackets 214 on the upper frame 12. The spool support 226 mounted on the spindle 212 contacts the inside of the spool of the scrim material 224.

A layer of scrim material 216 may be unwound from the spool 224 and passed through the nip rollers 218 and 220 to the prepreg material 82 and the scrim material layer 216 just prior to the deposition of the prepreg material, The leg material can be coupled to the prepreg material 82 as it is unwound from the prepreg spool 80. The prepreg material 82 to which the scrim material is applied forms the scrim reinforcing prepreg 222, which is then positioned by the tension roller 47 near the surface of the molding tool 60. As the carriage 10 moves across the molding tool 60 the squeeze roller 48 contacts the scrim reinforcing prepreg 222 and presses against the surface of the molding tool 60 to squeeze the prepreg tape .

The application of the scrim layer to the prepreg material just prior to the lamination of the prepreg material results in air evacuation between the first prepreg layer and the second prepreg layer that is subsequently deposited on the first layer of prepreg Provides a path for Direct attachment of the spool of scrim material to the cart provides greater flexibility when it is always necessary and / or undesirable to use a prepreg material having a scrim layer. In some embodiments, it is desirable to stack the prepreg layers without the scrim, and in other examples, the scrim reinforced prepreg layer is preferred.

The scrim material may include yarns that are arranged in a grid or open mesh and may be of any suitable material. Examples of the seal material include a thermoplastic seal, a glass seal, a cellulosic seal, and an aramid seal. Suitable materials for the scrim include polyesters such as polyethylene terephthalate and polybutylene terephthalate and copolymers thereof, polyamides such as nylon 6, nylon 66, nylon 10, nylon 11 and nylon 12, polyether sulfone, poly Propylene, viscose staple yarns, meta and para-aramids, fiberglass, jute, flax, cotton, and combinations of two or more thereof. Polyester scrim materials are available from, for example, Dextex Inc. of Georgia, a subsidiary of James Dewhurst.

The strands of the scrim may have a range of from about 40 to about 300 denier, or from about 50 to about 150 denier, or from about 50 to about 100 denier. The spacing of the warp and weft threads is from about 1 to about 10 per inch (1 to 10 per 2.54 cm) or about 2 to about 4 per inch (2 to 4 per 2.54 cm). In one embodiment, the spacing of the warp threads is 2 per inch (2 per 2.54 cm), and the spacing of the weft threads is 1 per inch (1 per 2.54 cm).

In one embodiment, the scrim material is comprised of a polyester thread having a woof yarn that is woof or sine wave type and a straight warp thread.

In another embodiment, the scrim material has a round cross-section that is arranged in a grid of fibers spaced approximately 3/8 inch (9.53 mm) apart at 0 ° or in a grid of fibers spaced 15/16 inch (23.82 mm) at +/- 45 °. Of the polyester fibers. Such scrim materials may be purchased from Bellingroth GmbH & Co. (Germany) under the trade designation Bafatex.

Yes

Four wheeled carts were configured to hold a spool of prepreg material having an outer diameter of 32 inches (81.3 cm) or less and an inner diameter of 12 inches (30.5 cm) and a length of approximately 1800 feet (549 meters). A 600 millimeter wide web of prepreg was finely cut into 12 strips 2 inches (50.8 mm) wide with a fixed knife mounted on a cart.

Approximately three spools of prepreg material were used to construct the wind turbine spar cap. The spool was mounted on the cart by an overhead crane or a forklift.

The wrinkle problem was reduced by stacking prepreg strips narrower than a predetermined radius of curvature. An analysis of this was performed for a radius of curvature of 130 feet (40 meters), as shown in Table 1 below. As can be seen from this particular analysis, when the strip is approximately 2.0 inches (5.0 cm) wide, the corrugation area is reduced to approximately 8% of the baseline for the 24 inch (61 cm) wide prepreg strip.

This exemplary layup can be obtained using a prepreg product comprised of 2 inch (5.1 cm) wide strips while the production and packaging of the individual prepreg strips is accomplished using a 24 inch (61.0 cm) wide prepreg It will add significant cost compared to starting with a product.

The apparatus and process of the present invention are particularly useful in the construction of wind turbine components. However, such devices and processes may also be used in the construction of aerodynamic components and structures for, for example, airplanes, helicopters, automobiles, trains, ships, and the like.

While the invention has been illustrated and described with respect to specific embodiments or embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art upon reading and understanding the details of the invention and the accompanying drawings. In particular, the terms (including references to "means") used to describe such elements in connection with the various functions performed by the elements (components, assemblies, devices, composites, etc.) It is to be understood that any element that performs the specific function of the elements described above (i.e., functionally equivalent), even if not structurally equivalent to the disclosed structure performing the function in the illustrated exemplary embodiments or embodiments of the present invention . ≪ / RTI > Furthermore, although specific configurations of the present invention may have been described above in connection with only one or more of several illustrated embodiments, it will be appreciated that such configurations may be advantageous and advantageous for any given or particular application, Configuration.

Claims (5)

A carriage for applying a resin-impregnated web to a contoured surface of a molding tool,
And an upper frame mounted on the base frame,
In the upper frame,
A first spool retaining assembly for retaining the spool wound with the resin impregnated web,
A second spool retaining assembly for retaining the spool on which the scrim material is mounted,
A web pressing assembly comprising a pressing roller configured to mate with the concave and convex portions of the surface of the molding tool for pressing the resin-impregnated web onto the surface of the molding tool;
A web tensioning system for applying tension on a resin-impregnated web is mounted,
The base frame
A plurality of wheels mounted on the base frame and supporting the carriage, the wheels engaging the surface of the molding tool to propel the carriage along the contoured surface of the wind turbine blade cap cap molding tool;
A tracking system for tracking a surface of a molding tool, the carriage comprising a tracking system movable reciprocally relative to an outline of a surface of the molding tool
Carriage. The method according to claim 1,
The upper frame is rotatably mounted on the base frame
Carriage. 3. The method of claim 2,
The upper frame is rotated at least 180 degrees on the base frame so as to change the application direction of the resin-impregnated web on the surface of the molding tool
Carriage. 4. The method according to any one of claims 1 to 3,
Further comprising a rotation table coupled to the base frame and the upper frame to allow rotation of the upper frame on the base frame
Carriage. The method according to claim 1,
Further comprising a nip for joining the layer of scrim material from the spool of scrim material to the resin-impregnated web prior to squeezing the resin-impregnated web onto the surface of the molding tool
Carriage.

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