A film material formed of thermoplastic polymer material is processed so as to have linearly extending regions (A) linked together by linearly extending webs (B), regions (A) and webs (B) each being oriented, the dominant direction of orientation in regions (A) forming an angle (V) to the direction on which (A) extends and webs (B) comprising arrays of linear furrows of thinner material or splits forming angles (U) higher than (V) to the direction in which (A) extends. The method of producing the new film involves passing an orientated film through a pair of intermeshing grooved rollers to cold-stretch the film in a direction at an angle to the predominant original orientation, at least one of the grooved rollers having crests with sharp edges to form the division between regions A and webs B and to stretch the material to form webs B while stretching the material less or not at all to form regions A. Preferably at least one of the grooved rollers has crests with a waved surface shape.

The invention concerns a process for preparing a ribbon of reinforcement strands or filaments associated on each of its faces with a polymeric binder, said ribbon having a given width substantially constant over its entire length, in which the strands or filaments extend in a direction parallel to the length of the ribbon, wherein it comprises the following steps: a) adjustment of the ribbon width to the desired width thanks to a dimensioning device, b) association of the ribbon on each of its faces with a polymeric binder allowing the assurance of a homogenous cohesion of the ribbon, such that the total weight of the binder does not exceed 25% of the total weight of the obtained ribbon,
as well as the ribbons obtainable by such a process.

The invention relates to a method for making a composite part including an assembly of superimposed webs of reinforcement threads imbedded at least partially in a polymer matrix, said part including at least one curved area and the method comprising steps of draping or stacking plies of a composite material, characterized in that, in at least one area adjacent to a curved area, at least one draping or stacking step is carried out with a ply of composite material, that comprises a web, or twisted thread web, including at least one twisted reinforcement thread in order to at least compensate the length differences of the extreme paths of the thread on either side of the width as measured in a direction parallel to the surface of the web; the invention also relates to the composite materials thus obtained.

The invention relates to a composite material in which at least one reinforcement thread is deposited on a surface according to a path having at least one curved area on the deposition surface, wherein the reinforcement thread is connected to the surface by a polymeric binder. A twist is applied to the reinforcement thread before the deposition thereof at least in order to compensate the length differences of the extreme paths of the thread on either side of the width as measured in a direction parallel to the deposition surface.

Semi-preg material is disclosed adapted for use in composite material comprising a) a first resin layer, b) covered on both side by layers of fibrous reinforcements whereby c) one of the two fabric layers is coated with a second resin layer and d) wherein said second resin layer has a tack level of not more than 100 N. Such semi-preg material has improved handling properties and contributes to the superior mechanical properties of the composite material formed therewith.

The invention concerns a process for preparing a ribbon of reinforcement strands or filaments associated on each of its faces with a polymeric binder, said ribbon having a given width substantially constant over its entire length, in which the strands or filaments extend in a direction parallel to the length of the ribbon, wherein it comprises the following steps: a) adjustment of the ribbon width to the desired width thanks to a dimensioning device, b) association of the ribbon on each of its faces with a polymeric binder allowing the assurance of a homogenous cohesion of the ribbon, such that the total weight of the binder does not exceed 25% of the total weight of the obtained ribbon,
as well as the ribbons obtainable by such a process.

A film material formed of thermoplastic polymer material is processed so as to have linearly extending regions (A) linked together by linearly extending webs (B), regions (A) and webs (B) each being oriented, the dominant direction of orientation in regions (A) forming an angle (V) to the direction on which (A) extends and webs (B) comprising arrays of linear furrows of thinner material or splits forming angles (U) higher than (V) to the direction in which (A) extends. The method of producing the new film involves passing an orientated film through a pair of intermeshing grooved rollers to cold-stretch the film in a direction at an angle to the predominant original orientation, at least one of the grooved rollers having crests with sharp edges to form the division between regions A and webs B and to stretch the material to form webs B while stretching the material less or not at all to form regions A. Preferably at least one of the grooved rollers has crests with a waved surface shape.

Novel structural materials composed of industrial hemp fiber with recycled high density polyethylene (HDPE) as well as methods for the production of the same are disclosed. The material's mechanical strength outperforms that of conventional lumber and could compete with glass fiber reinforced composites, particularly in tensile strength. In addition, this material offers many other significant advantages including insect free, high moisture resistance, no harmful chemical treatments, and no rapid corrosion in water environments.

A method for alignment of high aspect ratio materials (HARMs) within a liquid matrix by means of magnetic particles. The application of an external magnetic field creates a forced motion of the magnetic particles. This in turn leads to a laminar flow within the matrix which imposes a drag force on the HARMs, aligning the HARMs across the matrix. The used magnetic particles eventually accumulate at one end side of the matrix container and can be removed either by an incision or an extraction process. Unlike the previously proposed methods, there is no need for the magnetic particles to be attached either physically or chemically to the HARMs. Thus, the ultimate aligned HARMs are mostly pure and free of any magnetic particles. Once the matrix is a polymeric solution, the mentioned method is capable of synthesis of aligned HARMs-polymer composites, which exhibit improved mechanical and electrical properties.

A resin-soluble thermoplastic polymer veil toughening element for a curable composition wherein the polymer element is a non-woven veil in solid phase adapted to undergo at least partial phase transition to fluid phase on contact with a component of the curable resin matrix composition in which it is soluble at a temperature which is less than the temperature for substantial onset of gelling and/or curing of the curable composition and which temperature is less than the polymer elements melt temperature; a method for the preparation thereof, a preform support structure for a curable composition comprising the at least one thermoplastic veil element together with structural reinforcement fibers, methods for preparation thereof, a curable composition comprising the at least one thermoplastic veil element or the support structure and a curable resin matrix composition, a method for preparation and curing thereof, and a cured composite or resin body obtained thereby, and known and novel uses thereof.