EP3600859A1

EP3600859A1 - Method for producing an elongated article having a finished surface and an elongated article produced with said method

Info

Publication number: EP3600859A1
Application number: EP18718180.5A
Authority: EP
Inventors: Jani Korpimäki
Original assignee: Csi Composite Solutions And Innovations Oy
Current assignee: Csi Composite Solutions And Innovations Oy
Priority date: 2017-03-23
Filing date: 2018-03-14
Publication date: 2020-02-05
Also published as: FI20175273A; WO2018172607A1; FI129153B

Abstract

A method wherein fibers are laminated to form an elongated article (120), a shrink film (110) is mounted on the elongated article, and the elongated article is cured after mounting the shrink film to produce a finished surface. An elongated article formed with the method and a product containing the article is further included.

Description

METHOD FOR PRODUCING AN ELONGATED ARTICLE HAVING A FINISHED SURFACE AND AN ELONGATED ARTICLE PRODUCED WITH SAID METHOD

TECHNICAL FIELD

The present invention generally relates to a method for producing elongated articles having a finished surface, and articles produced with such method. The invention relates particularly, though not exclusively, to a method for producing elongated laminated composite articles having a finished surface, and articles produced with such method.

BACKGROUND ART

This section illustrates useful background information without admission of any technique described herein representative of the state of the art.

Composites are materials comprising at least two distinguishable components. Generally composites comprise a matrix component and a reinforcement component. An example of composites is fiber-reinforced polymer (FRP) composites. FRP composites comprise reinforcing fibers in a polymer matrix.

The characteristics of FRP composites depend on the properties of the reinforcement fibers, the properties of the polymer matrix, optional additives, and the manufacturing process. FRP composites are generally anisotropic, rendering the layup of the reinforcing fibers important.

Elongated articles, such as tubes or solid rods, can be formed by laminating fibers impregnated with matrix. Laminated composite articles are often designed to be light and strong, suitable for high-performance applications. Such properties are beneficial e.g. in sporting equipment. Particularly at the top level, there is a desire for light, strong, and precisely engineered high-performance equipment. Laminated composite tubes and rods are particularly suitable as sporting equipment shafts, such as ski-pole shafts and various club and stick shafts, e.g. golf club, floorball stick, or hockey stick shafts.

Laminated composite tubes can be formed with various techniques. Common techniques comprise wrapping matrix impregnated fibers around a mandrel. The fibers can be provided e.g. as filaments or rovings immersed into a resin bath, or as so called prepregs, i.e. reinforcing fabric incorporating an uncured matrix. The matrix impregnated fibers, provided e.g. as filaments, rovings, or prepregs, are placed around the mandrel such that a desired layup, i.e. fiber orientation and layer structure, is obtained. Several layers of fibers may be applied. Once the laminating step is terminated, a polymer tape is wrapped around the fibers. The tape may be e.g. a polypropylene, nylon or cellophane tape. The aim is to tighten the fiber structure and to apply a slight pressure on the laminated fibers. The fiber structure wrapped in tape is then cured to yield a hard and permanent laminated composite structure. Once cured, the mandrel and the tape are removed.

Composite articles obtained with the method described above have a rough, unfinished surface. To attain an article having a finished surface, such as a ski-pole shaft, or a club or stick shaft, a number of steps remain. First, the surface of the article is ground or sanded. After grinding or sanding, the surface of the article can be painted and a suitable coating, such as varnish or lacquer, is applied. Logos, labels, or other figures may be added in a separate step either prior to or after applying the coating. The finishing steps as described above are time consuming. Defects, such as nicks and local deviations from the desired thickness, are repeatedly formed during the sanding or grinding step. The formed articles may thus be of inconsistent quality. In applications, such as ski-pole shafts, where strength, stiffness, mass and mass distribution are often carefully designed, such inconsistences impact the performance of the final product.

As described above, there are shortcomings and limitations associated with forming elongated articles having a finished surface, such as shafts for sporting equipment. An objective of the present invention is to overcome at least some of the shortcomings and limitations, or at least to provide a new technical alternative for existing technology.

SUMMARY

According to a first example aspect of the invention there is provided a method comprising:

laminating fibers to form an elongated article;

mounting a shrink film on the elongated article; and

curing the elongated article after said mounting a shrink film to produce an elongated article with a finished surface.

The method of the first aspect enables the production of high-quality articles with less steps. The articles produced with said method have a continuous surface film, which film is of shrinkable material and mounted around the article before curing said article.

In certain embodiments, the curing step produces the elongated article with the finished surface. In certain embodiments, said curing produces a non-peelable finished surface, i.e., the shrink film cannot be peeled off the cured elongated article.

In certain embodiments, the mounted shrink film is uninterrupted in the longitudinal direction of the elongated article. In certain embodiments, the shrink film serves as a finishing coating. In certain embodiments, the shrink film is non-perforated.

In certain embodiments, the shrink film is a rectangular sheet. In certain embodiments, the shrink film is wrapped once to enclose the longitudinal surface of the elongate article. In certain embodiments, the shrink film is provided as a tubular sleeve. The tubular sleeve may be formed from a sheet. The tubular sleeve may be formed by attaching the longitudinal edges of a substantially rectangular sheet. In certain embodiments, the tubular sleeve is non-perforated. In certain embodiments, the method is performed without grinding and sanding. In these embodiments, the method does not comprise grinding and/or sanding the longitudinal outer surface of the elongated article. In certain embodiments, the method does not comprise painting, i.e., the method for producing an elongated article with a finished surface is performed without painting. In certain embodiments, the method does not comprise varnishing or lacquering, i.e., the method for producing an elongated article with a finished surface is performed without varnishing and lacquering. In certain embodiments, after curing the elongated article, the shrink film forms at least a portion of the outer surface of the cured elongated article. In certain embodiments, the shrink film serves as a coating.

In certain embodiments, the method comprises curing the elongated article after said mounting a shrink film to produce (i.e., the curing produces) an elongated article having an outer surface that is smooth throughout. In certain embodiments, the method comprises curing the elongated article after said mounting a shrink film to produce an elongated article having an unbroken surface. Particularly, in an embodiment the method comprises curing the elongated article after said mounting a shrink film to produce an elongated article having an unbroken outer surface in the longitudinal direction of the elongated article. In an embodiment, the method comprises curing the elongated article after said mounting a shrink film to produce an elongated article having an outer surface without joints formed by adjacent portions of the shrink film. Particularly, in an embodiment, the method comprises curing the elongated article after said mounting a shrink film to produce an elongated article having an outer surface without joints formed by adjacent portions of the shrink film across the width or circumference of the elongated article.

In certain embodiments, mounting the shrink film comprises shrinking said film. In certain embodiments, mounting the shrink film comprises heating the shrink film. In certain embodiments, mounting the shrink film comprises shrinking said film so that the film substantially follows the contour of the elongated article. In certain embodiments, the mounted shrink film applies a pressure on the elongated article. In certain embodiments, said pressure ranges from 7 psi to 140 psi, preferably from 14 psi to 28 psi. In certain embodiments, the thickness of the shrink film ranges from 0.01 mm to 2 mm, preferably from 0.05 mm to 0.5 mm. In certain embodiments, the shrink film is a heat shrink film. In certain embodiments, the shrink film comprises at least one thermosetting or thermoplastic polymer. In certain embodiments, the shrink film comprises PO (polyolefin), PET (polyethylene terephthalate), PE (polyethylene), PP (polypropylene), or a combination thereof, preferably PO, PET, or a combination thereof. In certain embodiments, the shrink film is resistant to ultra violet radiation.

In certain embodiments, the fibers are synthetic fiber. In certain embodiments, the fibers comprise carbon fiber, glass fiber, aramid fiber, or a combination thereof. In certain embodiments, the fibers comprise carbon fiber, glass fiber, or a combination thereof.

In certain embodiments, at least a portion of the fibers are provided as filaments. In certain embodiments, at least a portion of the fibers are provided as rovings. In certain embodiments, at least a portion of the fibers are provided as preforms.

In certain embodiments, the fibers are impregnated with a matrix. In certain embodiments, at least a portion of the fibers are impregnated with matrix before laminating fibers to form an elongated article. In certain embodiments, the fibers are immersed in a resin bath prior to laminating fibers to form an elongated article. In certain embodiments, the fibers are provided as prepreg. In certain embodiments, the prepreg comprises prepreg tape.

In certain embodiments, the matrix is a polymer matrix. In certain embodiments, the matrix comprises polyester, vinylester, polyurethane, or a combination thereof. In certain embodiments, the matrix comprises epoxy. In certain embodiments, the method comprises laminating fibers to form an elongated article having a rod-like shape. In certain embodiments, the method comprises laminating fibers to form an elongated article having a shaft-like shape. In certain embodiments, the elongated article has a solid core. In certain embodiments, the elongated article is hollow. In certain embodiments, the wall thickness of the elongated article ranges from 0.1 mm to 10 mm. In certain embodiments, the wall thickness varies in the longitudinal direction of the elongated article. In certain embodiments, the elongated article is at least slightly tapered.

In certain embodiments, the circumference of the elongated article is less than 1000 mm. In certain embodiments, the circumference of the elongated article ranges from 10 mm to 1000 mm, preferably from 30 mm to 300 mm. In certain embodiments, the length of the elongated article ranges from 0.5 to 3 m, preferably from 0.5 to 2 m.

In certain embodiments, the method comprises providing a mandrel on which the fibers are laminated. In certain embodiments, the method further comprises removing the mandrel to form a hollow tube. In certain other embodiments, the mandrel is not removed. In certain embodiments, the mandrel forms the core of the elongated article.

In certain embodiments, the elongated article is a ski-pole shaft, a walking pole shaft, or a roller skiing pole shaft.

The present inventors have developed a novel method for forming elongated articles with a finished surface. The present invention allows omitting finishing steps. Omitting finishing steps speeds up the manufacturing process and saves resources. Additionally, omitting finishing steps facilitates and simplifies automation of the manufacturing process. It is particularly beneficial to omit the grinding or sanding step described in the background section. Omitting the grinding or sanding step eliminates the defects and quality inconsistencies that originate from grinding or sanding. Omitting the sanding or grinding step allows formation of products of a more uniform quality. Additionally, the performance of the final product and designed properties, such as mass distribution, can be more precisely implemented. Hence, the performance of the final product can be better predicted.

The term "finished surface" is not limited to the surface of an end product, but in this context, a finished surface is a surface that can serve as the surface of an end product. A finished surface should be smooth enough for its intended use. The present invention in which the elongated article is cured only after said mounting of the shrink film does not prevent the application of optional or additional finishing or, especially, decorating steps after the step of curing the elongated article. In certain embodiments, the cured elongated article may be, for example, at least partially coated with a film, wherein said film optionally comprises print. According to a second aspect of the invention there is provided an elongated article with a finished surface produced with the method according to the first aspect of the invention.

According to a third aspect of the present invention there is provided a product containing the elongated article according to the second aspect of the invention.

In certain embodiments, the product of the third aspect is selected from a group comprising: a ski-pole, walking pole, roller skiing pole, a club, a stick, a bat, or other sporting equipment.

In certain embodiments, the material of the elongated article is fiber reinforced composite, wherein the matrix comprises a thermosetting polymer. In certain embodiments, the elongated article comprises a shrink film serving as a finishing coating. In certain embodiments, said shrink film forms an uninterrupted coating in the longitudinal direction of the elongated article. In certain embodiments, said shrink film forms a non-peelable finished surface, i.e., the shrink film cannot be peeled off the cured elongated article. In certain embodiments, the elongated article has a rod-like shape, or a shaft-like shape. In certain embodiments, the elongated article is hollow. In certain other embodiments, the elongated article is non-hollow, i.e. the elongated article is solid or comprises a solid core.

In certain embodiments, the elongated article has an outer surface that is smooth throughout. In certain embodiments, the elongated article has an unbroken surface. Particularly, in an the elongated article has an unbroken outer surface in the longitudinal direction of the elongated article. In an embodiment, the elongated article has an outer surface without joints formed by adjacent portions of the shrink film. Particularly, in an embodiment the elongated article has an outer surface without joints formed by adjacent portions of the shrink film across the width or circumference of the elongated article.

Products formed with the method of the present invention have improved mechanical properties. Mounting a shrink film on the elongated article before curing the elongated article improves particularly the fracture toughness of the elongated article. If a small fracture is formed in the elongated article due to e.g. an impact or hit, the elongated article formed with the method of the present invention is less likely to break when a load is applied on said fractured article than elongated articles formed with conventional methods. Additionally, mounting a shrink film on the elongated article before curing the elongated article aids in the formation of stiffer and stronger elongated articles. The stiffness and strength can be adjusted and controlled by material choice and fiber layup.

Different non-binding example aspects and embodiments of the present invention have been illustrated in the foregoing. The embodiments in the foregoing are used merely to explain selected aspects or steps that may be utilized in implementations of the present invention. Some embodiments may be presented only with reference to certain aspects of the invention. It should be appreciated that as a general rule corresponding embodiments apply to other aspects as well. BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments of the invention will be described with reference to the accompanying drawings, in which: Fig. 1 shows a schematic picture of an elongated article with a finished surface formed according to an embodiment of the invention;

Fig. 2a shows a schematic picture of laminated fibers according to an embodiment of the invention prior to mounting the shrink film; Fig. 2b shows a schematic picture of a shrink film being mounted on laminated fibers according to an embodiment of the invention;

Fig. 3a shows a schematic picture of a cross section profile of the elongated article according to an embodiment of the invention;

Fig. 3b shows a schematic picture of a cross section profile of the elongated article according to another embodiment of the invention; and Fig. 4 shows a flow chart of a method according to an embodiment of the invention.

DETAILED DESCRIPTION

In the following description, like reference signs denote like elements or steps.

Fig 1 shows a schematic picture of an elongated article 100 having a finished surface formed with a method according to an embodiment of the present invention. Fig. 1 further shows laminated fibers 120 and a shrink film 1 10, wherein the laminated fibers 120 form the elongated article and the shrink film 1 10 is mounted such that it covers the elongated outer surface of the elongated article 100.

In certain embodiments, the elongated article 100 comprises composite material. In certain embodiments, the elongated article 100 comprises fiber-reinforced polymer (FRP) composite, preferably carbon-fiber-reinforced polymer (CFRP) composite. In certain embodiments, the elongated article 100 comprises fiber reinforced plastic. In certain embodiments, the elongated article 100 comprises fiber reinforced composite, wherein the matrix of said composite comprises a thermosetting polymer.

In the present description the term shrink film refers to a polymer film that shrinks under certain conditions. Such conditions depends on the material and may be a certain temperature range, or evaporation of solvents. In certain embodiments, the shrink film 1 10 is a heat shrink film. In certain embodiments, the shrink film 1 10 shrinks in at least one direction. In certain embodiments, the shrink film 1 10 shrinks in two directions. In certain embodiments, the thickness of the shrink film 1 10 increases as the area of the shrink film 1 10 decreases. Preferably, the shrink film 1 10 shrinks in the width direction. In certain embodiments, the shrink film 1 10 comprises at least one thermosetting or thermoplastic polymer. Such polymers comprise PO, PET, PE, PP, or a combination thereof, preferably PO, PET, or a combination thereof.

In certain embodiments, the shrink film comprises one layer. In certain other embodiments, the shrink film 1 10 is formed of at least two layers. The at least two layers may comprise different polymers and have different shrinking ratios. In certain embodiments, the mounted shrink film 1 10 applies a pressure on the elongated article 100. In certain embodiments, said pressure ranges 7 psi to 140 psi, preferably from 14 psi to 28 psi.

In certain embodiments, the thickness of the shrink film 1 10 ranges from 0.01 mm to 2 mm, preferably from 0.05 mm to 0.5 mm.

In certain embodiments, at least a portion of the shrink film 1 10 is transparent. In certain embodiments, at least a portion of the shrink film 1 10 is opaque. In certain embodiments, the shrink film 1 10 comprises color. In certain embodiments, the shrink film 1 10 comprises a coloring agent. In certain embodiments, the shrink film 1 10 comprises print. In certain embodiments, there is print on only one side of the shrink film 1 10. In certain embodiments, the side of the shrink film 1 10 on which there is print is laid against the laminated elongated article 100. In certain embodiments, the print on the shrink film 1 10 is used to decorate, brand, or label the elongated article 100, or to achieve a combination thereof. In certain embodiments, decorative figures, such as stickers, are placed between the shrink film 1 10 and the laminated elongated article 100 before curing the elongated article 100. In certain embodiments, the shrink film 1 10 serves as a finishing coating. In certain embodiments, after curing the elongated article, the shrink film forms at least a portion of the outer surface of the cured elongated article. In certain embodiments, the shrink film 1 10 serves as a coating. In certain embodiments, the shrink film 1 10 forms a continuous film or coating in the elongated direction of the elongated article 100.

In certain embodiments, the shrink film 1 10 is a rectangular sheet. In certain embodiments, the shrink film 1 10 is wrapped once to enclose the longitudinal surface of the elongate article 100. In certain embodiments, the shrink film 1 10 is provided as a tubular sleeve. In certain embodiments, the tubular sleeve has been formed from a sheet. In certain embodiments, the tubular sleeve has been formed by attaching the longitudinal edges of a substantially rectangular sheet.

Fig. 2a shows a schematic picture of laminated fibers 120 according to an embodiment of the invention.

In certain embodiments, the fibers are synthetic fiber. In certain embodiments, the fibers comprise carbon fiber, glass fiber, aramid fiber, or a combination thereof. In certain embodiments, the fibers comprise carbon fiber, glass fiber, or a combination thereof. In certain embodiments, the fibers comprise nanoengineered fiber. In certain embodiments, the fibers comprise nanomaterial, such as nanoparticles. The nanoparticles may be carbon nanoparticles, such as carbon nanotubes, polymeric nanoparticles, metallic nanoparticles, or a combination thereof. In certain embodiments, the fibers are laminated such that the fibers gain a predetermined orientation. In certain embodiments, the fibers are oriented in three dimension. In certain embodiments, the fibers are applied in layers. The orientation of the fibers in different layers may vary. In certain embodiments, the orientation of the fibers varies within a layer. The thickness of the individual fiber layers may vary. In certain embodiments, different portions of the elongated article 100 have a different amount of layers. In certain embodiments, at least a portion of the fibers are provided as roving, mat, tape, filament, bundle, or a combination thereof. In certain embodiments, the fibers can be provided e.g. as filament or roving immersed into a resin bath. In certain embodiments, at least a portion of the fibers are provided as preforms. In certain embodiments, the preforms comprise stitches. In certain embodiments, the fibers are at least partially woven. In certain embodiments, the fibers are at least partially braided. In certain embodiments, the fibers are at least partially knitted.

In certain embodiments, at least some of the fibers form woven fabric. The fabric may comprise fibers in three dimensions. In certain embodiments, the woven fabric is formed before laminating fibers to form an elongated article 100. In certain other embodiments the woven fabric is formed while laminating fibers to form an elongated article 100.

The fibers may be treated before laminating fibers to form an elongated article 100. In certain embodiments, the fibers are impregnated with a matrix. In an embodiment, the fibers are impregnated with matrix before laminating fibers to form an elongated article 100. In another embodiment, the fibers are impregnated with a matrix after laminating fibers to form an elongated article 100. In certain embodiments, at least a portion of the fibers is immersed in a resin bath before laminating fibers to form an elongated article 100. In certain embodiments, at least a portion of the fibers are provided as prepreg, i.e. reinforcing fabric incorporating an uncured matrix. In certain embodiments, the prepreg comprises prepreg tape.

In certain embodiments, the matrix is a polymer matrix. In certain embodiments, the matrix is provided as a resin solution. In certain embodiments, the matrix comprises a thermosetting polymer. In certain embodiments, the matrix comprises epoxy, vinylester, polyester, polyamide, polyurethane, or a combination thereof. In certain embodiments, the matrix comprises epoxy. In certain embodiments, the matrix comprises additive. In certain embodiments, the additive is a coloring agent. In certain embodiments, the matrix comprises nanomaterial. In certain embodiments, the matrix comprises nanoparticles. The nanoparticles may be carbon nanoparticles, such as carbon nanotubes, polymeric nanoparticles, metallic nanoparticles, or a combination thereof. In certain embodiments, the fiber to matrix ratio ranges from 10% to 90%.

Fig. 2b shows a shrink film 1 10 according to an embodiment of the invention being mounted on laminated fibers 120. The shrink film 1 10 is mounted such that it covers at least a portion of the elongated outer surface of the laminated fibers 120.

In certain embodiments, mounting a shrink film 1 10 on the elongated article 100 comprises shrinking said film. In certain embodiments, mounting the shrink film 1 10 comprises heating the shrink film. The heating may be performed with a heat gun, or a heat blower, or in a heat tunnel, or in an oven. In certain embodiments, mounting a shrink film 1 10 on the elongated article 100 comprises shrinking said film to substantially follow at least a portion of the surface of the elongated article 100. In certain embodiments, mounting a shrink film 1 10 on the elongated article comprises shrinking said film such that the shrunken film is in contact with the outer longitudinal surface of the elongated article 100. In certain embodiments, mounting the shrink film 1 10 comprises shrinking said film so that the film substantially follows the contour of the elongated article 100. In certain embodiments, mounting the shrink film 1 10 comprises shrinking said film so that the film applies a pressure on the elongated article 100. In certain embodiments, the mounted shrink film 1 10 is uninterrupted in the longitudinal direction of the elongated article 100. In certain embodiments, said uninterrupted shrink film 1 10 is shorter than the elongated article 100. In certain embodiments, the shrink film 1 10 cannot be peeled off the cured elongated article 100. In certain embodiments, the shrink film 1 10 is fixedly attached to the cured elongated article 100. In certain embodiments, the shrink film 1 10 forms a solid part of the cured elongated article 100. In certain embodiments, the shrink film 1 10 cannot be easily detached from the cured elongated article 100.

Figs. 3a and 3b show cross sections of elongated articles according to certain example embodiments of the invention. Fig. 3a shows an elongated article 100 having a substantially circular cross section profile. Further, Fig. 3a shows laminated fibers 120 forming the elongated article 100, wherein a shrink film 1 10 is mounted around the elongated article 100 such that the film covers a portion of the elongated outer surface of said article. Fig. 3b shows an elongated article 100' having a substantially rectangular cross section profile. Further, Fig. 3b shows laminated fibers 120 forming the elongated article 100', wherein a shrink film 1 10 is mounted around the elongated article 100' such that the film covers a portion of the elongated outer surface of said article.

In certain embodiments, the elongated article has a substantially circular cross section profile. In certain embodiments, the elongated article has an oval cross section profile. In certain embodiments, the elongated article has a substantially rectangular cross section profile. In certain embodiments, the elongated article has a substantially triangular cross section profile. In certain embodiments, the cross section profile of the elongated article has rounded or flattened corners. In certain embodiments, the elongated article has an aerodynamically beneficial cross section profile. In certain embodiments, the elongated article has an irregularly shaped cross section profile.

In certain embodiments, the elongated article is substantially straight. In certain embodiments, the elongated article has at least one bend. In certain embodiments, the elongated article is curved. In certain embodiments, the elongated article is parallel. In certain embodiments, the elongated article is at least slightly tapered.

In certain embodiments, the elongated article has a solid core. In certain embodiments, the elongated article is hollow. In certain embodiments, the wall thickness of the elongated article ranges from 0.1 mm to 10 mm. In certain embodiments, the wall thickness varies in the longitudinal direction of the elongated article. In certain embodiments, the elongated article is included in a sporting equipment. In certain embodiments, the elongated article is included in a ski-pole. In certain embodiments, the elongated article is a shaft. In certain embodiments, the elongated article is a ski-pole shaft, a walking pole shaft, or a roller skiing pole shaft.

Fig 4 shows a flow chart of a method according to an embodiment of the invention. In step 410, fibers are laminated to form an elongated article. In a second step 420 a shrink film is mounted on the elongated article, and in a third step 430 the elongated article is cured. The curing is performed only after the shrink film mounting step.

In certain embodiments, laminating fibers to form an elongated article comprises filament winding. In certain embodiments, laminating fibers to form an elongated article comprises applying a tension on fibers and winding said fibers on a rotating mandrel. In certain embodiments, laminating fibers to form an elongated article comprises immersing fibers in a resin bath, and then winding the immersed fibers on a rotating mandrel.

In certain embodiments, laminating fibers to form an elongated article is performed trough a filament winding process, a prepreg-method, manual lamination, or a combination thereof. The filament winding process may be a continuous winding process, or a discontinuous winding process. In certain embodiments, laminating fibers to form an elongated article is performed manually. In certain embodiments, laminating fibers to form an elongated article is performed with a laminating apparatus. In certain embodiments, laminating fibers to form an elongated article is performed with a filament winding machine. In certain embodiments, the filament winding machine is a two axes machine. In certain other embodiments, the filament winding machine is a four axis, or six axes machine.

In certain embodiments, mounting a shrink film on the elongated article is performed manually. In certain embodiments, mounting a shrink film on the elongated article is performed with a suitable device or apparatus. In certain embodiments, mounting a shrink film on the elongated article comprises (in addition to an actual mounting step in which the shrink film is set in its place) a shrinking step in which said film is shrunken. In certain embodiments, the shrinking is performed by heating. In certain embodiments, the heating is performed in a heat tunnel, or in an oven. In certain embodiments, the heating is performed with a heat gun, or a heat blower.

In certain embodiments, curing the elongated article is performed in room temperature. In certain embodiments, curing the elongated article comprises heating. The heating may be perform with radiant heaters, or by placing said elongated article in an oven.

In certain embodiments, after mounting the shrink film, the shrink film is shrunken and the article cured by a single heating step (i.e., in a combined shrinking and curing step).

In certain embodiments, the method is performed without the steps of grinding or sanding the longitudinal outer surface of the elongated article. Accordingly, in certain embodiments, the method is performed without grinding or sanding. In certain embodiments, the method is performed without painting. In certain embodiments, the method is performed without varnishing or lacquering. The curing step produces the finished surface. In certain embodiments, the disclosed method of producing an article with a finished surface does not comprise post curing operations. However, it should be noted that once the article with a finished surface has been produced, the produced article may be assembled together with other part(s) to manufacture a complete product, such as a ski-pole.

In certain embodiments, the method comprises printing on a shrink film before mounting the shrink film on the elongated article. In certain embodiments, the method comprises providing fiber rovings. In certain embodiments, the method comprises immersing fibers in a resin bath prior to laminating fibers to form an elongated article. In certain embodiments, the method comprises providing fiber preforms not yet impregnated with matrix. In certain other embodiments the method comprises proving fibers as prepregs. In certain embodiments, the method comprises providing the matrix as a resin solution.

In certain embodiments, the method comprises providing a mandrel on which the fibers are laminated. In certain embodiments, the method comprises laminating fibers on a mandrel. In certain other embodiments the method further comprises removing the mandrel to form a hollow tube. In certain other embodiments the mandrel is not removed. In certain embodiments, the mandrel forms the core of the elongated article. In certain embodiments, the mandrel is a polymer mandrel. In certain embodiments, the mandrel comprises metal, wood, polymer foam, or a combination thereof.

Various embodiments have been presented in the foregoing. It should be appreciated that in this document, words comprise, include and contain are each used as open-ended expressions with no intended exclusivity. The foregoing description has disclosed non-limiting examples of particular implementations and embodiments of the invention. It is however clear to a person skilled in the art that the invention is not restricted to details of the embodiments presented in the foregoing, but that it can be implemented in other embodiments using equivalent means or in different combinations of embodiments without deviating from the characteristics of the invention.

Furthermore, some of the features of the afore-disclosed embodiments of this invention may be used to advantage without the corresponding use of other features. As such, the foregoing description shall be considered as merely illustrative of the principles of the present invention, and not in limitation thereof. Hence, the scope of the invention is only restricted by the appended patent claims.

Claims

Claims:

1 . A method comprising:

laminating fibers to form an elongated article;

mounting a shrink film on the elongated article; and

2. The method according to claim 1 , wherein said curing produces a non-peelable finished surface.

3. The method according to claim 1 or 2, wherein the mounted shrink film is uninterrupted in the longitudinal direction of the elongated article.

4. The method according to any preceding claim, wherein the shrink film is provided as a tubular sleeve.

5. The method according to any preceding claim, wherein the method is performed without grinding and sanding.

6. The method according to any preceding claim, wherein mounting a shrink film on the elongated article comprises shrinking said film.

7. The method according to any preceding claim, wherein the shrink film comprises at least one thermosetting polymer.

8. The method according to any preceding claim, wherein the fibers comprise carbon fiber, glass fibers, or a combination thereof.

9. The method according to any preceding claim, wherein the fibers are impregnated with a matrix.

10. The method according to claim 9, wherein the matrix is a polymer matrix, preferably an epoxy matrix.

1 1 .An elongated article with a finished surface produced with the method according to any of claims 1 to 10.

12. A product containing the elongated article of claim 1 1 .

13. The product of claim 12, wherein the product is selected from a group comprising a sporting equipment, a ski-pole, walking pole, roller skiing pole, a club, stick, and a bat.