(19) & (11) EP 2 110 309 A1 (12) EUROPEAN PATENT APPLICATION (43) Date of publication: (51) Int Cl.: 21.10.2009 Bulletin 2009/43 B63H 9/06 (2006.01) (21) Application number: 08154582.4 (22) Date of filing: 15.04.2008 (84) Designated Contracting States: (72) Inventors: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR • Claushuis, Theodorus Johannes Maria HR HU IE IS IT LI LT LU LV MC MT NL NO PL PT B-3621, Lanaken (BE) RO SE SI SK TR • Backer, Jan Adolph Dam Designated Extension States: 5694 WN, Son en Breugel (NL) AL BA MK RS (74) Representative: Brouwer, Hendrik Rogier (71) Applicant: ToBeOne Consulting and Commerce Patentwerk B.V. B.V. P.O. Box 1514 1251 GM Laren (NL) 5200 BN ’s-Hertogenbosch (NL) (54) Sailcloth of flexible composite laminate and method of making a sail thereof (57) The invention relates to sailcloth (20) comprising be locally reinforced by additional unidirectional and/or a flexible composite laminate (10) of at least two stacked woven sheets and/or tapes (611,612,...). The invention unidirectional sheets (1,2) of parallelly arranged drawn also relates to a method for producing the sailcloth, and polymeric tapes (11,12,21,22,23,24). The sheets are at to a sail comprising the sailcloth according to the inven- least partly adhered to each other such that the sailcloth tion. The sailcloth is extremely light weight, durable and has a stable three- dimensional shape. The sailcloth may shows excellent form consistency. EP 309 2 110 A1 Printed by Jouve, 75001 PARIS (FR) 1 EP 2 110 309 A1 2 Description tional film layers. The unidirectional sheets of the flexible laminate provide for the stiffness and strength needed [0001] The present invention relates to sailcloth com- for good sailing performance, and are optimally arranged prising a flexible composite laminate and to methods for in discontinuous and/or continuous trajectories from one making products thereof. The sailcloth is particularly use- 5 edge of the sail to another edge thereof, to substantially ful for making a sail for sail craft or other pliant lifting carry the load imposed on the sail. The use of unidirec- structures, or for making cover sheets to protect against tional sheets of parallelly arranged drawn polymeric wind and/or rain. tapes instead of yarns or chords provides a more even [0002] Conventional sails are typically fabricated from stress distribution across the sail, which leads to strength a number of separate flat panels of woven cloth. The flat 10 and wear levels that are unexpectedly high, given the panels are first cut into the desired predetermined shape, fact that the strength of tapes is generally lower than the and adjacent panels are joined together by sewing or strength of yarns of chords. broad seaming to provide a sail having a three-dimen- [0006] Another advantage of the three-dimensionally sional or airfoil shape. Rather than using woven cloth to shaped sailcloth according to the invention is that it can make the panels, it has been proposed in US 4,708,080 15 be manufactured in its final dimensions, which typically for instance to use flat laminates of film and individual are above 1 m2, more preferably above 2 m2, and most reinforcing threads to make the flat panels, which are preferably above 5 m2. later joined together in a conventional fashion. The re- [0007] In an alternative embodiment a three-dimen- sulting structure, however, will still have a number of sionally shaped sailcloth is provided comprising a flexible seams between the adjacent panels, and these seams 20 composite laminate of at least two stacked woven sheets may contribute to excessive stretch or imperfect load of drawn polymeric tapes, the sheets being at least partly transfer when the sail is placed under load. adhered to each other such that the sailcloth has a stable [0003] US 5,097,784 discloses an improvement over three-dimensional shape. Such an embodiment has es- the above-described sail by providing a sail in which the sentially the same advantages as described above. body of the sail is in the form of essentially a one piece 25 [0008] Crimp or geometrical stretch in the known sail or unitary three-dimensional laminated construction. The is usually considered to be due to a serpentine path taken laminated construction comprises a plurality of pre- by a yam in the sailcloth. In a weave, for instance, the fill stretched yarns or threads disposed between two film and warp yarns are going up and down around each oth- layers. The yarns or threads extend in a continuous and er. This prevents them from being straight and thus from uninterrupted fashion over the surface of the sail from 30 initially fully resisting stretching. When woven sailcloth is edge to edge to provide the unitary construction. The loaded, the yarns tend to straighten before they can begin disclosed sail minimizes the need for seams and the at- resist stretching based on their tensile strength and re- tendant problem of stretch between the seams. A disad- sistance to elongation. Crimp therefore delays and re- vantage of the disclosed sail however is that it needs duces the stretch resistance of the yarns at the time of additional film layers to make the laminate impervious to 35 the loading of the sailcloth. The sail according to the wind. This adds to the weight of the sail. Moreover, the present invention does not have this disadvantage. known sail is difficult to make, and provides limited design [0009] In a preferred embodiment of the sailcloth ac- flexibility. Because the yarns are continuous, there is a cording to the invention, the tapes of two subsequent fixed relationship between yam trajectories and the yam sheets extend at an angle between 15 and 90 degrees densities achieved. This makes it difficult to optimize yam 40 to each other. In another preferred embodiment of the densities within the sail. Indeed, a compromise must be sailcloth according to the invention, the sailcloth is char- sought between the yam density in a particular area of acterized in that the tapes of two subsequent sheets ex- the sail, and yam alignment across the complete length tend squarily to each other. Such an arrangement (also of a trajectory. Also, it has turned out that the known sail referred to as a ’cross-ply’) improves the shear strength is relatively prone to fracture or wear. 45 of the sailcloth. [0004] One object of the present invention is to provide [0010] In a further preferred embodiment of the sail- a sailcloth of a flexible composite laminate, particularly cloth according to the invention, the sailcloth is charac- useful for making a sail or cover sheet, with which the terized in that the tapes of two subsequent sheets extend above-mentioned disadvantages may at least partly be in the same direction and are arranged in an orderly fash- overcome. 50 ion, whereby tapes overlap either below or above, or [0005] The sailcloth according to the invention is there- both, over the total length with regard to a first sheet, or to characterized in that it comprises a flexible composite over part of the trajectory. This embodiment yields a sub- laminate of at least two stacked unidirectional sheets of stantially unidirectional assembly of two adjacent sheets. parallelly arranged drawn polymeric tapes, the sheets Such a sheet is useful when one wants to optimize the being at least partly adhered to each other such that the 55 specific properties of the sail. With specific properties are sailcloth has a stable three-dimensional shape. The sail- meant properties divided by weight. cloth according to the invention is inherently substantially [0011] Although not necessary to the invention, the impervious to wind, and therefore does not need addi- sailcloth may be characterized in that it additionally com- 2 3 EP 2 110 309 A1 4 prises at least one polymeric film sheet in a stacked ar- at least a second plurality of drawn polymeric tapes of rangement with the flexible composite laminate. The ad- polymeric material over said first sheet on the mold sur- ditional polymeric film sheet may be impervious to wind face in a parallel arrangement to form a second sheet, or other environmental action. Polymeric sheets are and consolidating said sheets together on said mold at needed in the state of the art, such as disclosed in US 5 elevated temperature and/or pressure. 5,097,784, to hold the yarns. However, crimp in sailcloth [0016] The method of the invention provides an easy made of laid-up yam can easily occur, for instance by manufacturing process for a sailcloth using standard lam- lateral shrinkage of the polymeric films during conven- ination procedures, known in the art. Moreover, a sail is tional lamination processes. This is because the heated provided with improved design flexibility. Indeed the uni- film shrinks laterally as it undergoes thermoforming, 10 directional sheets of parallelly arranged polymeric tapes which considerably deforms the yarns and is catastrophic may be positioned in the sail according to the stress in- with regard to the stretch performance of the composite tensity distribution, whereby tape density and tape align- fabric in highly loaded applications. Since the sailcloth ment are optimized with the engineering flexibility to ad- according to the invention does not need polymeric film just the tape intensity over the total or partial length of sheets to hold the tapes, its shape is well controlled due 15 the trajectories from one edge of the sail to another edge. to the absence of crimp, which generally occurs when Alternatively, tapes as such can be arranged for optimi- using yarns.