Abstract: The invention provides a process to orient a high molecular weight polymer film, formed from molten, dispersed or dissolved state, characterised in that as a start of this orientation process the film becomes embossed in a pattern of closely spaced dots or thin short lines, 5 thereby becoming oriented within these embossments, whereafter the orientation process is continued in one or more steps by m.d. stretching, t.d. stretching, or combined m.d. and t.d. stretching, whereby the embossed and oriented dots or lines gradually grow and develop until essentially the entire film has become oriented.

Abstract: Apparatus for longitudinal orientation of thermoplastic film material (4) comprises a width-reduction zone upstream of the longitudinal stretching zone, through which the width of the film is gradually reduced so as to allow longitudinal stretching without necking. The width-reduction zone comprises at least one, preferably several, pairs of pleating rollers (16, 17) comprising intermeshing grooves or discs for pleating the material, the length of said width reduction zone preferably being less than 3 times the original width of the film. The width-reducing zone has upstream (14) and downstream (15) rollers or roller assemblies, with curved axes and optionally also conveyor belts for providing smooth width reduction. Longitudinal stretching is preferably between at least two, and preferably more than two, pairs of stretching rollers (9, 10, 11, 12) which are relatively close together.

Abstract: Methods include at least one sequential stretching step between circular or spiralized grooved rollers and the sequential stretching is performed according to at least one of six aspects of the invention.

Abstract: Crosslaminates of thermoplastic films have at least one of the films formed as a fluted structure, and two films are laminated to one another in such a manner that pockets are formed which contain gas. The pockets allow passage of gas between at least two adjacent flutes, whereby the product has an improved handle, and bags formed of the laminate have good stacking properties when filled with coarse particulates. The flute pitch is generally no more than 3 mm, while the pocket length is less than 50 mm. The bonding method involves spot bonding between the films, achieved by adhering the films together between crown portions of bosses on one film with molten material on the other film under a low pressure process, for instance achieved by provision of air pressure through adaptation of production apparatus, for instance die portions.

Abstract: 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.

Abstract: Crosslaminates of thermoplastic films have at least one of the films formed as a fluted structure, and two films are laminated to one another in such a manner that pockets are formed which contain gas. The pockets allow passage of gas between at least two adjacent flutes, whereby the product has an improved handle, and bags formed of the laminate have good stacking properties when filled with coarse particulates. The flute pitch is generally no more than 3 mm, while the pocket length is less than 50 mm. The bonding method involves spot bonding between the films, achieved by adhering the films together between crown portions of bosses on one film with molten material on the other film under a low pressure process, for instance achieved by provision of air pressure through adaptation of production apparatus, for instance die portions.

Abstract: A method of forming a film (1) of molten polymer material, by extruding said material in a direction (2) out of a narrow exit slot (3), which is an integral part of a wider die chamber (4) of which the major dimension of extension is parallel with the major dimension of the exit slot (3), characterized in that the molten polymer material is formed into one or more flows generally parallel with said major dimension of the exit slot (3), each said flow being pumped in a re-circulating arrangement from the chamber inlet (7) to the outlet (8) through conduits connecting the inlet to the outlet, while fresh molten polymer material is administered from a reservoir into each re-circulating flow.

Abstract: 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.

Abstract: 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.

Abstract: Methods include at least one sequential stretching step between circular or spiralized grooved rollers and the sequential stretching is performed according to at least one of six aspects of the invention.

Abstract: A blend of two partly incompatible polymers is extruded to form a film under conditions such that the alloy in the blend comprises fibrils extending mainly in one direction, the width and thickness of each fibril having a mean lower than 5 ?m, the fibrils being formed of the polymer component having a higher melting point, and the fibrils being surrounded by a matrix of the second polymer, which has a lower coefficient of elasticity. The special morphology is achieved by providing grids in a grid chamber upstream of the exit orifice of the extrusion die, and by sequential hot stretching at a temperature at which the higher melting polymer is at least partly crystalline, and cold stretching, at which both polymers are substantially solid. The second, cold stretching step, is carried out under conditions to give an elongation at break at 20° C. of at least 25%. The films are of particular value for forming crosslaminates having high shock resistance.

Abstract: Apparatus for longitudinal orientation of thermoplastic film material comprises a width-reduction station upstream of a longitudinal stretching station, through which a width of the film is gradually reduced so as to allow longitudinal stretching without necking.

Abstract: A pattern of embossment is made by a method producing short linear, mutually parallel bosses not directly formed by indentation, but formed by first making continuous, mutually parallel fine pleats or waves, and then interrupting this configuration at intervals by localized shrinkage.

Abstract: 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.

Abstract: Crosslaminates of thermoplastic films have at least one of the films formed as a fluted structure, and two films are laminated to one another in such a manner that pockets are formed which contain gas. The pockets allow passage of gas between at least two adjacent flutes, whereby the product has an improved handle, and bags formed of the laminate have good stacking properties when filled with coarse particulates. The flute pitch is generally no more than 3 mm, while the pocket length is less than 50 mm. The bonding method involves spot bonding between the films, achieved by adhering the films together between crown portions of bosses on one film with molten material on the other film under a low pressure process, for instance achieved by provision of air pressure through adaptation of production apparatus, for instance die portions.

Abstract: Crosslaminates of thermoplastic films have at least one of the films formed as a fluted structure, and two films are laminated to one another in such a manner that pockets are formed which contain gas. The pockets allow passage of gas between at least two adjacent flutes, whereby the product has an improved handle, and bags formed of the laminate have good stacking properties when filled with coarse particulates. The flute pitch is generally no more than 3 mm, while the pocket length is less than 50 mm. The bonding method involves spot bonding between the films, achieved by adhering the films together between crown portions of bosses on one film with molten material on the other film under a low pressure process, for instance achieved by provision of air pressure through adaptation of production apparatus, for instance die portions.

Abstract: Method and apparatus for longitudinal orientation of thermoplastic film material (20) comprises a width-reduction zone upstream of the longitudinal stretching zone (9, 10), through which the width of the film is gradually reduced so as to allow longitudinal stretching without necking. The width-reduction zone comprises at least two sets of pleating rollers (7, 1) comprising intermeshing grooves or discs for pleating the material. The downstream (1) rollers comprise a mini-roller defined by the following measures a) the pitch of the corrugations, measured from middle of tip to middle of each neighboring tip is 20 mm or less; b) the perimeter from middle of a tip to the middle of each neighboring tip measured along the corrugated roller surface, divided by the said pitch is in the range between 1.10 and 1.80; and c) the diameter of the mini-roller, measured at the tips of the corrugations, is at the highest 4 times the said pitch.

Abstract: 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.

Abstract: A crosslaminate is formed from two oriented plies of thermoplastic polymer material, arranged so that their orientation directions cross one another, the plies being heat sealed together. Each ply is semi-fibrillated, that is consist of linear thin regions of biaxially oriented material and thicker linear bosses between the thinner regions. The webs are sealed primarily through bonds formed at the intersection of the bosses (thicker regions). The array of bosses has a division less than 2 mm. The laminate has improved aesthetic and strength properties. A method for forming the crosslaminate involves segmental stretching of the material to form the thinner regions, and apparatus comprising intermeshing grooved stretching rollers having sharp-edged crests is described.

Abstract: A laminate of thermoplastic film materials exhibiting throughgoing porosity and comprising plies A and B, A having an inner surface A1 partly in contact with B and an outer surface A2, and B having an inner surface BI partly in contact with A and an outer surface B2, A and B consisting of continuous material except for a multitude of perforations in each ply, whereby essentially no perforation in A corresponds directly to a perforation in B, the lamination between A and B on surfaces A1 and B1 being a) through a coextruded lower melting lamination layer on A and/or B and b) established in such discontinuous manner that there is formed a channel system between A1 and B1 connecting the majority of the perforations in A each with at least one of the perforations in B, and connecting the majority of the perforations in B each with at least one of the perforations in A is provided in addition to a process and apparatus for producing such a laminate.