JP2012533444A - Method and apparatus for producing a laminate comprising an oriented and finely corrugated film and the resulting product - Google Patents

Abstract

  In the method for producing a laminate of an oriented and corrugated film (A) and a film or web (B), at least the film (A) is made of an orientable crystalline polymer material, and the film (A ) Is stretched in an arrangement with respect to the angle formed by the linear nip (D-F) formed between the rollers or bars, while being acute with respect to a plane perpendicular to the linear nip ( u) is brought into this nip in the direction of forming and subsequently pulled by the traction means (1 and 2) below an acute angle (v) with respect to the perpendicular plane and measured at the opposite face of this plane When (v) is greater than (u) but less than 85 °, this creates a stretch and uniaxial molecular orientation, the stretch ratio (GD: FE) and the angles (u) and (v) are stretched The above mentioned The angle of orientation of the film (A) is selected to deviate less than 15 ° from its longitudinal direction and result in a decrease in film width, the decrease measured in the direct line being in the longitudinal direction Greater than the reduction in width caused by longitudinal stretching so as to form a corrugation extending to the front, and the corrugation is stabilized before contacting the traction means (1 and 2) and the film (B ) Is laminated to the film (A) while maintaining the wavy groove shape of (A) after the film (A) has left the nip (DF).

Description

  The object of the present invention is clear from the title of the invention. Corrugated boards of thermoplastic sheet material have been known for over 40 years. The use of these known products is generally similar to that of cardboard. This is because both provide high rigidity against bending in one direction. However, recent inventions have aimed at low-wave undulating groove shapes to adjust the board properties by the laminate and provide the properties of a flexible but rigid film, while at the same time providing several properties. In order to improve, orientation techniques, and preferably cross-laminating techniques are used. In particular, tensile strength, yield tension, and tear propagation resistance.

  Thus, WO 02/102592 (Rasmussen) is preferably oriented in the machine direction, preferably in a single layer, with a wavy groove shape with a wavelength of 3 mm or less extending in the longitudinal direction. The present invention relates to a laminate, preferably cross laminates. Another layer preferably has no wavy groove shape and is provided with a lateral orientation.

  Another known document, WO 04/54793 (Patent Document 2) (Rasmussen), aims to achieve stiffness against bending in each direction, and to achieve this goal. In addition, one layer of the laminate is provided with a undulating groove shape along its machine direction, and the other layer is provided with a undulating groove shape in the transverse direction, and at least In one, the wavelength of the wavy groove shape is 5 cm or less, preferably much shorter.

  In any of the above-mentioned documents by Rasmussen, the construction of a wavy groove shape in the machine direction (md) occurs by using a roller having a circular groove portion. The rollers with these grooves are interdigitated and the lamination takes place between the rollers with the grooves and the smooth, rubber-coated rollers. The roller with the groove for lamination is in the state of being accurately recorded with the roller with the groove to provide the waved groove shape, and the roller with the groove described first is the last described Since it has a temperature higher than that of the roller having the groove, the pitch of the groove must be different from each other when the ambient temperature is taken into consideration. In the examples in the above two documents, the pitch of the groove on the lamination roller is 1.0 mm. However, in any document, the pitch of the groove shape (m. d.) is stated to be 0.8 mm due to shrinkage of the laterally oriented film after bonding.

  The second mentioned Rasmussen document is m. d. Mentions several methods of forming a wavy groove shape perpendicular to the. In the most practical method (see claim 67), the film having the lateral wavy groove shape is provided with a groove in the longitudinal direction in a minute pattern (that is, the groove is md). On the laminating roller (perpendicular to m). d. Line-bonded to the oriented film and bonded m. d. Shrinkage occurs after the alignment film is stabilized. Here, the unbonded areas of the other films bend and form a wavy groove shape.

  Prior to conceptualizing the present invention, the inventors thoroughly researched the market for the application of technology in the aforementioned Rasmussen literature. The second Rasmussen reference states that “for applications such as waved groove-shaped textiles, the wavelength in both layers is preferably as short as possible, so that it is economical for the manufacturing process. It can be said that. Here, the laminated body of low gauge such that the waved groove shape has a wavelength of about 0.5 mm or less, so that the waved groove shape is hardly visible or looks like a high-quality textile structure. It is clear that the market interest is being directed to.

International Publication No. 02/102592 Pamphlet International Publication No. 04/54793 Pamphlet US Pat. No. 6,139,938 US Pat. No. 2,505,146 US Pat. No. 3,491,158 British Patent No. 1078732 US Pat. No. 5,361,469

  In accordance with that line, the present invention can be applied to the above-described manufacturing method for providing a vertical wavy groove shape to form a horizontal wavy groove with a pitch of less than 0.5 mm without extreme difficulty. (See Examples 2 and 3 of the present invention in this regard). However, according to the present invention, m. d. Calculations and experiments related to the above-described technique for providing a wavy groove shape are industrially applicable, but the width of the laminate is a very fine pattern of lamination and groove in roller temperature control. It was shown that it would be limited to about 30-50 cm due to the accuracy in machining. It strictly limits the possibility of obtaining an accurate “record” between a grooved roller to form a wavy groove shape and a laminated roller provided with the groove. In conclusion, m. d. There is a strong need to devise a completely different method for forming and laminating films having a fine wavy groove shape extending in the direction.

  In this regard, it should be mentioned that to the best of our knowledge, the shortest known wavelength of corrugated paper laminate is about 1.8 mm. This is described in US Pat. No. 6,139,938 (Lingle et al.) (Patent Document 3).

  The present invention is based on a technique known from US Pat. No. 2,505,146 (Ryan), issued in 1950. The method steps described at the beginning of claim 1 of the invention are known from the patent literature, but as is clear from the part describing the features of claim 1, special conditions are selected in the present invention, And a lamination process is added. To understand the scope of the claims, it is recommended to review FIG. 1 and the corresponding description.

  The present invention is first studied for the purpose of producing a laminate, wherein (B) is also a thin film made of a crystalline orientable polymer material, but the film (B) Can be, but is not limited to, for example, a paper film, a metal foil, or a textile web.

  Ryan focuses on forming molecular orientation in the bias, and in a preferred implementation of his technique, angle (v) is less than angle (u), which is the technique used in the present invention. In contrast to However, in the corresponding descriptions in FIGS. 6 and 17, and columns 25 and 32, Ryan explains that angle (v) can be greater than angle (u), He does not disclose that his technique can be applied to form flat and stable longitudinal corrugations in the film. By examining FIG. 4 of the present invention, it can be seen that the very fine and uniform waves formed by the use of the present invention are surprisingly rarely expected from Ryan.

  Reference is also made to US Pat. No. 3,491,158 (Rasmussen), issued in 1966. This differs from the Ryan patent in that the nip holds the film support during stretching and is formed by a normal pair of nip rollers, i.e., with an angle (u) of zero, It is similar to Ryan in that the film is drawn while being drawn downward at an angle (v) from the nip. This stretching is performed at an elevated temperature. This old Rasmussen method actually forms fine, longitudinally extending pleats or corrugations. As in the present invention, this is done by reducing the width of the film in the excessive width reduction caused by stretching the film. However, these fine pleats or wave shapes are not stabilized and are not maintained for the manufacture of corrugated laminates. In contrast, the pleats are pressed flats and are used to reinforce the final longitudinal stretch, for example for the purpose of producing twisted or industrial yarns by microfibrosis.

  This special modification of Ryan's technology for special purposes can also be applied to the present invention, but the compression of the corrugated structure is avoided, the corrugation is stabilized and the final stretching step is omitted. . However, in the old Rasmussen method described above, the angle (v) is 70-85 ° (see claim 3) and at the same time the angle (u) is zero, so that the width is very large. This is unsuitable for most applications of the present invention.

  Referring back to claim 1 of the present invention, the described angle and stretch ratio selection will be better understood by examining FIG. 1 and the associated description, as already described. Reference is made to the extensive material processing in the Ryan patent. “Reduction in width caused by stretching in the longitudinal direction” is a factor that can be measured in the laboratory. Laboratory measurements can be performed on narrow (eg, 2 cm wide) continuous film samples that are stretched at temperatures and speeds selected for industrial processes. .

  Claim 1 provides that when the film (A) leaves the nip (D-F), the direction of orientation therein deviates less than 15 ° from its longitudinal direction, while this deviation is preferably 10 °. Is less than 5 °, particularly preferably less than 5 °.

  A device particularly suitable for feeding film (A) into nip (DF) under angle (u) is disclosed in British Patent No. 1078732 (Rasmussen), issued in 1967. Yes. This device is a "Segmental Rollers", i.e. a nip is formed between a pair of rotating rollers (5), each of which has three or more axially movable segments ( 6), these segments reciprocate along the axial direction in conjunction with the rotation of the roller, so that the film always goes to the nip (DF) at the same angle (u). Supplied.

  The aforementioned British patent relates to splitting a strongly oriented film to obtain a fibrous network. The rubber belt used in the microfibration process is not necessary for the present invention, but the segment for at least one of the rollers must be rubber coated to form a nip. Since the surface of the roller is usually heated to, for example, 60 to 80 ° C., and a low frictional force is preferable, the rubber is preferably silicone rubber.

  As is clear from FIG. 1 and the related description, the relationship between the angle u, the angle v, the stretch ratio EF: DG, and the reduction in the achieved width DE: GF will be fixed. If a high stretch ratio in combination with providing deep corrugations or pleats is desired, the film fed to the nip (D-F) is uniaxially oriented, preferably coincident with its longitudinal direction or at most from the longitudinal direction. Must be in an unbalanced biaxial orientation with a major direction that deviates by 20 ° or coincides with its longitudinal direction or deviates by at most 20 ° from the longitudinal direction Will. Strong melt orientation will be sufficient.

  The stabilization required before the corrugated film contacts the traction device (roller) is performed in the simplest form by heating it before the film contacts the nip, which is then heated. The The heated film must be cooled again, usually by air, before coming into contact with the traction means (1) and (2), preferably immediately after leaving the nip. The surprising stability of the corrugations can be achieved by a suitable high film temperature during the corrugation and subsequent cooling as described above. In special cases, stabilization is obtained by irradiation.

  Alternatively or additionally, films (A) and (B) after film (A) has exited the nip (DF) and before contacting the traction means (1) and (2) Stabilization can be established by performing the stacking process. However, in the normal sequence, lamination occurs when film (A) exits the traction means. This can be done on different production lines.

  In either case, the bond is established as a line bond or spot bond limited to the high pleat (wave) portion on one side of the film (A). The third film (C) can also be laminated on the opposing surface of the film (A). In the simplest form, film (B) and / or film (C) is formed by extrusion coating and oriented only by stretching in the molten state.

  However, in order to produce a film having good strength in all directions, the laminate is cross-laminated, i.e. the film (B) is at an angle with respect to the longitudinal direction of the film (A). It is preferable that they are oriented. This joint can be formed by extrusion lamination or a laminate layer coextruded on each of film (A) and film (B). It is important that the film (A) corrugations are effectively stabilized so as to avoid significant flattening of the corrugations during lamination. Nevertheless, it is important to perform the lamination under a very low lamination pressure, as will be further explained in connection with FIGS. 3 and 3a.

  If the film (B) is composed of a crystalline orientable polymer material prior to lamination, the film (B) is preferably subjected to uniaxial molecular orientation or unbalanced biaxial molecular orientation, This gives the film strength in the main direction extending in the transverse direction, i.e. m. d. A certain angle is formed. This angle is preferably from 40 to 90 °, particularly preferably 90 °, if this is allowed in view of implementation (including machinery costs). Orientation at 90 ° in the transverse direction may be performed, for example, by a prior art tenter frame at about 80-90 ° C., preferably when free longitudinal shrinkage is allowed during width expansion. it can.

  In an apparatus that performs bias stretching, the angle (v) is preferably made adjustable. The angle (u) cannot be adjustable unless the device controlling the reciprocation of the segment is interchangeable. As mentioned above, (u) can be zero in a very special case. In another extreme case, the angle is close to 90 °, for example about 85 °. Usually, however, the angle should be in the range of about 15 ° to about 60 °.

  A cam arrangement that transfers the rotation of the "segment roller" to the reciprocating motion of each segment is described in the aforementioned British patent (Patent Document 6). However, if the angle (u) is greater than about 50 °, the cam device needs to be equipped with multiple aerodynamic (hydraulic) pistons, one to act on each segment. There will be.

  Appropriate methods for forming transversely extending corrugations on film (B) and subsequently laminating the film (B) on film (A) without damaging the corrugations are evident from claims 10-13. And will be further described in connection with FIGS. 3 and 3a.

  Regardless of whether embodiments of the present invention are used, a suitable composition for each of films (A) and (B) is HDPE, LLDPE or crystalline so as to form at least 50% for each film. PP is included.

  The third film (C) can be laminated on the film (A) on the side opposite to the film (B).

  Protection is also recited in the claims for the combination with the apparatus described herein and is suitable for carrying out the method of the invention. Furthermore, the present invention encompasses products made by this method.

  The present invention will be described in more detail with reference to the accompanying drawings.

FIG. 1 is a main drawing used to clarify claim 1. FIG. 2 is a schematic of a “segment roller” adapted to build a nip where corrugations are formed and to carry film (A) to this nip at an angle (u) perpendicular to the axis of the rollers. FIG. FIG. d. The film (A), which is oriented in the shape and provided with the fine wavy groove shape, is line bonded to the flat film (B) without distributing the wavy groove shape of the (A). And how the t. d. The groove shape waved in the shape of m. d. It is a figure which shows whether it is provided by shrinkage | contraction. FIG. 3a is a photomicrograph of the laminated roller shown in FIG. 3, actually made for testing in Examples 2 and 3 and other laboratories, one end of the roller FIG. 5 is a view showing a fine pattern groove portion that is viewed from the above and thereby restricts bonding to a line pattern. FIG. 4 is a photomicrograph of a film produced as described in Example 1, showing a cross-section with uniform and fine corrugations.

  In FIG. 1, a film (A) that has already received a relatively strong orientation in its longitudinal direction is drawn into the nip (DF) at an angle (u) perpendicular to the nip. The nip is formed between two “segment rollers” shown in FIG. Each roller consists of a core (5) and a segment (6), which is provided with a rubber coating (7). The segment (6) is movable in the axial direction with respect to the core (5) and travels in the track. The apparatus comprises a curved track disposed on at least one end of the roller and a corresponding cam on the segment such that the curvature of the track causes the segments to rotate as the roller rotates relative to the track. The curvature is such that it reciprocates in the longitudinal direction. Although these tracks are shown here in a simplified structure, in practice they should usually include special roller bearings. As the “segment roller” rotates, the segment reciprocates, performing one “advance” and one “retract” during one rotation. As described above, this is usually arranged by using a cam at one end of each roller (see the above-mentioned drawing in Patent Document 6). However, the cam can be replaced by or supplemented by suitable aerodynamic or hydraulic means incorporated in the roller, controlled by or controlling the rotation of the roller.

  Returning to FIG. 1, film (A) is pulled out of the nip (DF) by roller pair (1) and roller pair (2) and stretched there by movement at the same speed as the circumferential speed of those roller pairs. . This extraction is performed at an angle (v) that is greater than the angle (u) between the reference plane relative to the nip and the extraction direction.

  If accurate longitudinal orientation is desired, the film (A) will have a straight line drawn at 90 ° to the longitudinal direction of the film (A) before it contacts the nip, such as a line (DE) Even after passing through the nip, a straight line in the longitudinal direction, for example perpendicular to the line (GF), which exists after the film (A) must be maintained. In that case, the circle drawn on the film before it contacts the nip is transformed into an ellipse with a major axis parallel to the new longitudinal direction of the film, m. d. The line drawn perpendicular to is essentially m. d. Will remain as a straight line perpendicular to.

  If point (E) (when drawn on film) moves to point (F) (on the nip), point (D) (when drawn on film) will move to point (G). Therefore, the stretch ratio, ie the ratio between the entry speed and the discharge speed, will be (DG) divided by (FE). In FIG. 1, the film (A) is shown to move in the same plane before and after the nip DF that provides stretching. In practice, the film (A) is not necessary, but preferably should exceed an arc along one side of the “segment roller”, for example 10-20 °. This helps to prevent the film from wrinkling. However, it will be quite complicated to show this in the figure. Upon exiting the nip, the film may again follow one roller surface over a small arc, but this is not a positive effect. In the situation where the film (A) is along the roller surface before and / or after the nip DF, FIG. 1 should be understood as an unexpanded representative example.

  These considerations are essentially based on the condition that all stretching takes place in or immediately after the nip DF. To ensure this, the film is efficiently air cooled immediately after leaving the nip. This is conveniently done by applying an air die that is placed immediately after the nip and terminates with a wall of fine porous material that is parallel to the film and that contacts most of the film. can do.

The inherent tendency of film (A) to shrink can be accurately established by laboratory experiments, as stated in the overview above.
a) This inherent shrinkage ratio, multiplied by a factor related to the desired waveform depth,
b) Angle (u), and c) Stretch ratio,
The angle (v) can be easily calculated based on trigonometry. Thus,
Stretch ratio DG / FE = sin v / sin u, and
Total t. Consisting of inherent shrinkage and special waveform. d. Shrinkage ratio:
DE / GF = cos u / cos v is easily calculated.
See also the calculation of Example 1.

  Although not shown in FIG. 1, it is understood that the film (A) passes through each of the two roller pairs (1) and (2) in the “S path”. During this pass, running of the corrugated structure must be avoided, so that each of these four rollers can be coated with a soft rubber and the two rollers (1) are It is not necessary to form a nip with respect to each other. The roller pair (2) can form a nip, but should exert almost zero nip pressure. Upon leaving these pulling rollers, the film (A) can be rolled up or directly advanced to the lamination process performed as shown in FIG.

  In FIG. 3, a thin film (B) is coextruded, thereby providing a low melting laminate. The film can be oriented in any direction, but preferably m. d. Is substantially perpendicular to. This film can be a reel or a t. d. It can be supplied directly from the stretching device.

  An alternative technique for obtaining a 90 ° orientation of the film is described in US Pat. No. 5,361,469 (Rasmussen), column 4, line 39 to column 5, line 6. Yes. Here, the tubular film is oriented at an angle (eg 30 °) by relative rotation between the circular exit orifice and the haul off roller, and subsequently the film is oriented at an angle (eg 60 °) to form a 90 ° orientation. This can only be melt orientation, but nevertheless this method is very suitable for the present invention.

  The orientation direction in (B) is m. d. Need not be about 90 °, but typically should not be less than about 40 °. Such an angle of orientation is m. d. It can be formed by cutting a tubular material oriented in a spiral manner.

  M. d. It is noted that the formation of a wavy groove shape extending below 90 ° possible with respect to is independent of the orientation direction in (B). For example, m. d. Film oriented at 40 ° with respect to m. d. It is possible to form a fine wavy groove shape extending at 90 ° to the angle. The film (B) is guided to a rubber-coated roller (8) under very low tension (control means not shown). The roller has an ambient temperature, but the subsequent laminating roller (9) in contact with the roller is heated to a temperature that melts or semi-melts the laminating layer. There are minute axial grooves (12) on the surface of the roller (9). These grooves are shown in the micrograph FIG. 3a.

  This minute groove limits the bonding between the fine pattern of the bonding line and the unbonded space. The pitch of the groove pattern can be as low as 0.3 mm as can be seen from the micrograph.

  This thin film (B) is heated almost instantaneously to the temperature selected for lamination. When (B) is composed of HDPE, LLDPE, LDPE or crystalline PP, a low melting layer will be provided and a suitable temperature will be about 80-110 ° C. depending on the layer. The film (B) is t. d. When in a strongly oriented state, the film must be properly stabilized at a similar or higher temperature to avoid lateral shrinkage before it is fed into the device. Such stabilization is described in WO 04/54793 (Rasmussen) (patent document 2) in connection with FIG.

  The film (B) is laminated with the film (A) when the film (A) exits the “segment roller” stretching process, which provides a waved groove shape extending in the longitudinal direction. The film (A) is also provided with a low melting point laminated layer. The two sets of traction rollers (1) and (2) in FIG. 1 are replaced in FIG. 3 by three rollers (10), which are all coated with soft rubber, and all of them are Driven at the same speed adjusted as described in connection with 1. Those rollers have an ambient temperature. Line bonding occurs when the two films mentioned above contact on the laminating roller (9). Film (A) is not heated before film (B) is melted. In this step, the film (A) remains tensioned in the longitudinal direction as it exits the “segment roller”. In order to maintain the wavy groove shape of the film (A), only along a short adjustable arc, eg about 20 °, along the hot lamination roller. Thereby, only a small part of each waved groove shape is flattened and heated.

  The laminate of (A) and (B) is formed through a fine porous material on the air die (11) through a pressurized air film. The air has an ambient temperature and acts to cool and smooth the films.

  The tension in the laminate is maintained by two driven pulling rollers (12) and an idling nip roller (13). Both rollers (12) are coated with soft rubber and rollers (13) are coated with cellular rubber.

  Since the three pulling rollers (10), the laminating roller (9) and the two pulling rollers (12) are all driven at the same circumferential speed, the film (A) is also in contact with the nip roller (13). Still under high longitudinal tension. When leaving the nip, the film (A) is relaxed while being rolled up, but the unbonded space in the film (B) is bent to form a waved groove shape, and all adjustments are correct.

  Of particular importance is the tension in the film (B) when in contact with the idling rubber-coated nip roller (8). When this tension is high, it is clear that the formation of the wavy groove shape of (B) does not occur due to the contraction of (A). If this tension is close to zero, heating on the laminating roller (9) causes m. d. Expansion occurs, which causes film (B) to be partially out of contact with the roller. Therefore, the tension when the film (B) contacts the roller (8) must be adjusted very accurately. Electrostatic charging of the film (B) by corona discharge helps to maintain good contact of the film (B) with the roller (9) with low tension.

  The selection of the arc along which the film (A) runs over the laminating roller (9) is also important. As a result, the position of the cooling die (11) can be adjusted.

  While the tension in film (A) is usually sufficient to create the pressure required for bonding, in some cases it can be captured by the action of a pressurized air film, which is microporous. It is made of a material and acts on the surface of the film (A) facing the film (B). This is not shown in the figure.

Example 1
A three-layer tubular PE film is extruded from a 1.5 mm circular extrusion port with a blow ratio (BUR) of 2: 1 and a gauge of 0.017 mm. The composition is as follows.
Intermediate layer: 60% of the total is plain high molecular weight HDPE,
Outer layer: ethylene copolymer that begins to melt at 80 ° C.
Inner layer: plain LLDPE with melt flow index 1

  An experimental “segment roller” device (see claim 3 and FIG. 2) was used, which was configured for the resulting developments of the old British patent mentioned above (Patent Document 6). . In this device, the angle (u) is 17 ° and changing this angle would be a substantial task. The pulling roller (see FIG. 1, reference numerals 1 and 2) is incorporated so that the angle (v) and the stretch ratio can be easily changed.

  A 20 cm wide strip of tape is cut from the extruded tubular, flat film and stretched at 70 ° C. in different ratios. This is the temperature selected for stretching with this "segment roller" apparatus. Here, the break occurred at a draw ratio of 3.0: 1, and the width of the tape was 1.1 mm just before the break, that is, the inherent lateral shrinkage ratio was 2.0: 1. It turns out that it is 1-1.8: 1.

  The low final draw ratio is due to the high melt orientation in the starting film. This high melt orientation is an advantage of the present invention, otherwise it would have been necessary to pre-orient the film in the manner of the prior art, for example at 70 ° C. This is because a strict longitudinal orientation and corrugation is preferred in the final film, and therefore, as calculated in the description of FIG. 1, the draw ratio is sin v / sin 17 ° −sin v / 0. .29. In the very ultimate case, when (v) reaches 90 °, thereby, when the angle u = 17 °, 1: 0.29 to 3.4: 1 for the draw ratio in the “segment roller” apparatus Limits are set.

  A stretch ratio of 2.6: 1 is selected to protect against breakage. It has been discovered that stretching at this ratio essentially reduces the width from 20 mm to 14 mm, as the stretching experiment is performed at 70 ° C. on a 20 mm wide tape. This means that the inherent shrinkage ratio is (2.0: 1.4): 1 = 1.43: 1.

  A trial angle (v) = 60 ° is selected. According to the equation in the description of FIG. 1, this will reduce the overall width with the ratio cos 17 ° / cos 60 ° −0.95: 0.5 = 1.90: 1. This inherent shrinkage ratio of 1.43: 1 leaves a ratio of 1.90 / 1.43 = 1.33: 1 to create the wave shape, which is considered acceptable.

  On the other hand, the direction of orientation will be strictly longitudinal. To achieve this, the stretch ratio should be sin 60 ° / sin 17 ° = 0.87: 0.29 = 3.0: 1.

  However, since the deviation from the longitudinal orientation is considered very low, the stretching in the “segment roller” apparatus is carried out with v = 60 °, a temperature of 70 ° C. and a draw ratio of 2.6: 1. Here, it is confirmed that the deviation from the longitudinal orientation is negligible.

  The obtained wave shape is clear from FIG. As already mentioned above, the wave shapes are surprisingly uniform. The film can be laminated with a film (B) having a similar composition that does not have a wave shape under a low lamination pressure.

Example 2
In this example, a fully drawn / laminated line combining the devices of FIGS. 1, 2, 3 and 3a was used (with some modifications, see below). Both films (A) and (B) were based on LLDPE. Prior to the “segment roller” stretching step, the film (A) is m.m. in the form of a 120 mm wide ribbon. d. Starting as a melt oriented film, film (B) started as a 60 ° melt oriented film in the form of a 55 mm wide ribbon before the lamination step. Its 60 ° orientation is described in m.p. as described in US Pat. No. 5,361,469 (Rasmussen). d. This was achieved by helical cutting of melt oriented tubes. It is noted that the starting orientation in (B) is 60 ° or less, but the direction of the wavy groove shape is now vertical.

The two sets of pulling rollers (1) and (2) in FIG. 1 for the laboratory stretching / laminating line were replaced with three pulling rollers (10) in FIG.

  The roller (8) has not yet been tried as a nip roller in FIG. The roller acted as an idling roller located equidistant from the laminating roller (9).

  The air film cooling device in FIG. 3 was replaced with a simple metal block, which had approximately ambient temperature at the beginning of each test run. Since each test run was short, it was not necessary to cool it.

  The diameter of the laminating roller (9) was 32 mm, and its length was 52 mm.

  Referring to FIG. 1, the angle u was 17 ° and the angle v was 60 °, both of which were similar to Example 1.

With respect to the extruded film, films (A) and (B) were removed from separate tubular films that differ only in gauge. The gauge of the extruded film for (A) was 0.030 mm and the gauge of the extruded film for (B) was 0.015 mm. All were coextruded from a three component die. The composition is as follows.

  The main layers extruded as the core and inner layers were 85% of the total and 100% LLDPE (Dowlex 5056).

  The outer layer (of the laminate) was 15% of the total and consisted of an ethylene copolymer (Attane SL4102) with a melting point of about 80-90 ° C.

  The outlet gap in the coextrusion die was 1.5 mm and the blow ratio was 1.8: 1.

Drawing / Lamination Conditions The surface of a “segment roller” coated with black rubber was heated by infrared and controlled at 50 ° C. The lamination roller (9) was heated to 80 ° C. by circulating hot water.

  When measured on the final laminate, the stretch ratio of the relaxed film (A) was 3.0: 1. Thus, it was found that (A) having an accurate longitudinal orientation was produced.

  The unwinding tension in the film (B) was adjusted so that a groove shape that was as deep as possible was formed in the film (B).

  Experiments with the position of the metal block (11) minimize the flattening of the wavy groove shape in the film (A) without losing the bond between the films (A) and (B). .

Results The film (A) had a waved groove shape with a waved groove wavelength of 0.5 mm and a groove depth of 0.23 mm.

The film (B) had a waved groove shape corresponding to the pitch on the roller (9) and a waved groove shape with a groove depth of 0.09 mm.
Final gauge of laminate: 32 g / m ²
Final m. d. Tensile tension: 24 N / cm width Final t. d. Tensile tension: 7 N / cm width

Example 3
For the two films (A) and (B), the same tubular film as in Example 2 was used with gauges of 0.030 mm and 0.015 mm, respectively. In this example, the transverse melt orientation of film (B) was tried. In an industrial process, this is conveniently done by the method described in US Pat. No. 5,361,469 (Rasmussen), column 4, line 39 to column 5, line 6. Can be achieved. This technique has already been briefly described in the above overview of the present invention. However, in this test, a 55 mm wide strip is taken from its extruded tubular film with its m.p. d. Was cut simply at 90 ° with respect to, and several such strips were joined using adhesive tape.

  The test procedure for the laminate provided with the waved groove shape was performed exactly as described in Example 2.

As a result, the film (A) had a waved groove shape with a waved groove wavelength of 0.5 mm and a groove depth of 0.01 mm.

The film (B) had a waved groove shape corresponding to the pitch on the roller (9) and a groove depth of 0.045 mm.
Final gauge of the laminate: about 30 g / m ² ,
Final tensile strength, m. d. : 26 N / cm width,
Final tensile strength, t. d. : 7.3 N / cm width

Claims (18)

  A method for producing a laminate of an oriented and corrugated film (A) and a film or web (B), wherein at least the film (A) comprises an orientable crystalline polymer material, The film (A) is stretched in an arrangement with respect to the angle formed by a linear nip (D-F) formed between rollers or bars, while being perpendicular to the linear nip To the nip in a direction that forms an acute angle (u) with respect to the surface and subsequently pulled by the traction means (1 and 2) below the acute angle (v) with respect to the perpendicular surface. (V) is greater than (u) but less than 85 ° when measured at the opposing surfaces of the film, in a process whereby stretch and uniaxial molecular orientation are formed, the stretch ratio (GD: FE) and angle ( u) and (v) The orientation angle of the stretched film (A) is selected so that it deviates less than 15 ° from its longitudinal direction and results in a reduction in film width and is measured at the direct line. The reduction is characterized in that it is larger than the reduction in width caused by the longitudinal extension so as to form a longitudinally extending corrugation and the corrugation is in contact with the traction means (1 and 2) Stabilized before, and film (B) is laminated to film (A) while maintaining the wavy groove shape of (A) after film (A) has left said nip (DF) The above method, further characterized in that:   The method according to claim 1, wherein (B) is also a film made of an orientable crystalline polymer material.   The nip is formed between a pair of rotating rollers (5), each of the rollers comprising a surface composed of three or more multiple axially movable segments (6), and the segments The segment contacts the film while being reciprocated along the axial direction in conjunction with rotation of the roller so that the film is always fed to the nip under the same angle (u) 3. A method according to claim 1 or 2, characterized in that it is moved in the opposite direction after.   4. A method according to claim 1, 2 or 3, characterized in that the deviation is less than 10 [deg.], Preferably less than 5 [deg.].   Prior to stretching in an angular orientation, the film (A) is supplied in a uniaxial orientation that coincides with its longitudinal direction or deviates by a maximum of 20 °, or coincides with its longitudinal direction, or 5. A method according to any one of claims 1 to 4, characterized in that it is supplied in an unbalanced biaxial orientation with a main direction deviating at most 20 [deg.].   The film (A) contacting the nip is heated and the nip is heated and the stretched film (A) is cooled before contacting the traction means (1 and 2). 6. A method according to any one of the preceding claims, characterized in that the cooling is preferably performed immediately after the film leaves the nip.   The joint according to claim 1, characterized in that the joint is formed by extrusion lamination or between respective laminate layers coextruded on film (A) and film (B). The method according to any one of the above.   3. A method according to claim 2, characterized in that the film (B) is subjected to a transversely stretching orientation prior to its lamination.   9. A method according to claim 8, characterized in that the orientation forms an angle of 40-90 [deg.], Preferably about 90 [deg.] With respect to the longitudinal direction.   Bonding occurs between the mutually facing laminated layers of film (A) and film (B) on the heated laminating roller, and the film (A) is in a tentered state in the longitudinal direction. For some time, the film (B) is in direct contact with the roller, and its bonding is limited to the laterally extending lines formed by providing longitudinal grooves in the laminated roller. And, following the joining, the laminated film is cooled and the film (B) has a wavy groove shape in the transverse direction by removing the tension in (A). 10. A method according to claim 2, 8 or 9, further characterized.   The method according to claim 10, wherein a pitch of the longitudinal grooves is 0.2 to 1.0 mm.   The method according to claim 10 or 11, characterized in that the pressure at which the film (A) and the film (B) are joined to each other is limited to the pressure caused by the tension in the film (A).   The pressure at which the film (A) and the film (B) are bonded to each other is the pressure generated by the tension in the film (A) and the pressure applied to the surface of the film (A) facing the film (B). 12. A method according to claim 10 or 11, characterized in that it is limited to a formed air film.   The lamination is an extrusion lamination using a tie film applied to a place where the film (A) and the film (B) are in contact with each other on a lamination roller. The method described in 1.   The third film (C) is laminated on a surface of the film (A) facing the film (B), according to any one of claims 1 to 14. Method.   Any combination of the devices described herein and suitable for carrying out the method according to the invention.   A product produced by the method of the present invention.   The method according to claim 2, characterized in that at least 50% of each of the films (A) and (B) consists of HDPE, LLDPE or crystalline PP.

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