Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C55/00—Shaping by stretching, e.g. drawing through a die; Apparatus therefor
  • B29C55/02—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets
  • B29C55/04—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets uniaxial, e.g. oblique
  • B29C55/045—Shaping by stretching, e.g. drawing through a die; Apparatus therefor of plates or sheets uniaxial, e.g. oblique in a direction which is not parallel or transverse to the direction of feed, e.g. oblique
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
  • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
  • B32B27/32—Layered products comprising a layer of synthetic resin comprising polyolefins
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form
  • B32B3/26—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer
  • B32B3/28—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer characterised by a layer comprising a deformed thin sheet, i.e. the layer having its entire thickness deformed out of the plane, e.g. corrugated, crumpled
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B38/00—Ancillary operations in connection with laminating processes
  • B32B38/0012—Mechanical treatment, e.g. roughening, deforming, stretching
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
  • B32B7/04—Interconnection of layers
  • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B38/00—Ancillary operations in connection with laminating processes
  • B32B38/0012—Mechanical treatment, e.g. roughening, deforming, stretching
  • B32B2038/0028—Stretching, elongating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/24—All layers being polymeric
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/514—Oriented
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/54—Yield strength; Tensile strength
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/50—Properties of the layers or laminate having particular mechanical properties
  • B32B2307/582—Tearability
  • B32B2307/5825—Tear resistant
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2307/00—Properties of the layers or laminate
  • B32B2307/70—Other properties
  • B32B2307/704—Crystalline
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B37/00—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
  • B32B37/14—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers
  • B32B37/15—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer being manufactured and immediately laminated before reaching its stable state, e.g. in which a layer is extruded and laminated while in semi-molten state
  • B32B37/153—Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding characterised by the properties of the layers with at least one layer being manufactured and immediately laminated before reaching its stable state, e.g. in which a layer is extruded and laminated while in semi-molten state at least one layer is extruded and immediately laminated while in semi-molten state

Definitions

• Corrugated boards of thermoplastic sheet material has been known for more than 40 years.
• the uses of these known products are generally similar to the uses of corrugated cardboards since both provide a high stiffness against bending in one direction.
• more recent inventions aim at low wavelengths of the fluting to make the laminate loose the character of board and give it the character of a flexible but stiffened film, at the same time as orienting and preferably also crosslaminating technologies are used for improvement of several properties. In particular tensile strength, yield tension and tear propagation resistance.
• Rasmussen concerns laminates, preferably crosslaminates, in which one ply, preferably oriented in the machine direction, has been supplied with longitudinally extending flutes of wavelength 3 mm or lower. Another ply is without fluting, and has preferably been supplied with a transverse orientation.
• the present invention is based on a technology known from US2505146 (Ryan) which issued in 1950.
• the method steps stated in the introduction to the present claim 1 is known from that Patent, but in the present invention special conditions are selected, and a lamination step is added, as it appears from the characterising part of claim 1.
• special conditions are selected, and a lamination step is added, as it appears from the characterising part of claim 1.
• the present invention is primarily conceived with a view to the manufacture of a laminate, in which (B) also is a thin film consisting of crystalline orientable polymer material, but for the sake of completeness it is mentioned that the film (B) is not limited so, but may e.g. be a paper film, a metal foil or a textile web.
• this old modification of the Ryan technology can also be applied in the present invention, provided compression of the waved structure is avoided, the waves are stabilised and the final stretching step is left out.
• the angle (v) is 70-85°, (see claim 3) at the same time as the angle (u) is zero, and this causes a very high reduction of the width, which for most applications of the present invention is unsuitable.
• the mentioned British Patent concerns splitting of strongly oriented film to obtain a fibrous network.
• the rubber belts used in that fibrillation process are not necessary in connection with the present invention, but the segments on at least one of the rollers must be rubber coated to form the nip. Since the surfaces of the rollers normally must be heated, e.g. to 60-80 0 C, and since a low friction is preferable, the rubber is preferably a silicone rubber.
• the film to be fed into the nip may need to be in a state of uniaxial orientation preferably coinciding with or deviating at the highest 20° from its longitudinal direction, or with an unbalanced biaxial orientation having a main direction coinciding with or deviating at the highest 20° from its longitudinal direction.
• a strong melt orientation may be sufficient.
• the stabilisation which is needed before the waved film meets the pulling devices (rollers) is in the simplest form carried out by heating the film before it meets the nip, and the nip is then also heated.
• the heated film must again be cooled, normally by air, before it meets the pulling means (1 ) and (2), preferably immediately as it leaves the nip.
• a surprising stability of the waves can be achieved by an adequately high film temperature during the formation of the waves, followed by the mentioned cooling. In special cases the stabilisation may be produced by irradiation.
• the stabilisation can be established by carrying out the laminate of the films (A) and (B) after (A) having left the nip (D- F) but before it meets the pulling means (1) and (2).
• the normal sequence is that the laminating takes place when film (A) has left the pulling means. It may be carried out on a different production line.
• the bonding is established as a line bonding or spot bonding limited to the crests on one side of film (A).
• a third film (C) may also be laminated to the opposite side of film (A).
• film (B) and/or film (C) is formed by extrusion coating and is oriented only by stretching in molten state.
• the laminate is preferably a crosslaminate, i.e. film (B) has been oriented under an angle to the longitudinal direction of film (A).
• the bonding can be formed by extrusion lamination or between coextruded lamination layers on film (A) and film (B). It is important that the waves of film (A) are efficiently stabilised to avoid any significant flattening of the waves during the lamination. Nevertheless it is important to carry out the lamination under a very low laminating pressure, as it further shall be described in connection with Figs. 3 and 3a.
• the film (B), when it consists of crystalline, orientable polymer material, is preferably supplied with a uniaxial or unbalanced biaxial molecular orientation, which gives the film a main direction of strength which is transversely extending, in other words forms an angle with the m.d.
• This angle is preferably between 40-90°, most preferably 90° when practical consideration (including cost of machinery) allows it.
• Transverse orienting at 90° can be carried out with a conventional tenterframe e.g. at about 80-90°C, preferably while a free longitudinal contraction is permitted during the expansion of the width.
• the angle (v) is preferably made adjustable.
• the angle (u) cannot be made adjustable, except that the devices which control the reciprocation of the segments may be exchangeable.
• (u) can in very special cases be zero. In other extreme cases it can be close to 90°, e.g. about 85°. However, normally it should be within a range from about 15° to about 60°.
• suitable compositions for each of the films (A) and (B) comprise HDPE, LLDPE or crystalline PP, to form at least 50% of each film.
• a third film (C) may be laminated to film (A) on the side opposite to film (B). Protection is also claimed for any combination of apparatus herein described and suitable for carrying out the method of the invention. Furthermore the invention comprises any product manufactured by this method.
• Fig. 1 is a principal sketch serving to clarify claim 1 .
• Fig. 2 is a sketch of the "Segmental Rollers" which establish the nip where the waving is formed, and which are adapted to convey the film (A) to this nip under an angle (u) to the perpendicular to their axes,
• Fig. 3 is a sketch showing how an m.d. oriented and finely fluted film (A), is line-bonded to a flat film (B) without distribution of the flutes (A), and how a t.d. fluting of (B) is developed by m.d. shrinkage of (A),
• Fig. 3a is a microphoto of a laminating roller shown in Fig. 3 and actually made for Examples 2 and 3 and other laboratory trials. It is seen from one of its ends thereby showing the fine pattern grooves, which makes the bonding limited to a pattern of lines,
• Fig. 4 is a microphoto of the film produced as described in Example 1 , showing the cross section with even and fine waves.
• Fig. 1 the film (A), which already may have received a relatively strong orientation in its longitudinal direction, is pulled into the nip (DF) under an angle (u) to the perpendicular to the nip.
• the nip is formed between the two "Segmental Rollers" shown in Fig. 2.
• Each consists of a core part (5) and segments (6), the latter supplied with a rubber coating (7).
• the segments (6) are axially moveable on the core (5), running in tracks.
• the apparatus comprises curved tracks positioned at at least one end of the rollers and corresponding with cams on the segment, the curvature of the track being such that the segments are reciprocated longitudinally as they rotate relative to the track.
• a straight line, drawn on film (A) under 90° to its longitudinal direction, such as the line (DE), before film (A) meets the nip, must after passage of the nip remain a straight line which is perpendicular to the then existing longitudinal direction of film (A), such as the line (GF).
• a circle, drawn on the film before the latter meets the nip will be transformed to an ellipse with its main axis parallel with the new longitudinal direction of the film, and a straight line drawn perpendicular to the m.d. will in essence remain as a straight line perpendicular to the m.d.
• the stretching ratio i.e. the ratio between the ingoing and outgoing velocities, will be (DG) divided by (FE).
• the film (A) is shown as if it moved in the same plane before and after the nip DF which localises the stretching.
• film (A) should preferably but not necessarily, over a certain arc e.g. 10-20°, follow the surface of one of the "Segmental Rollers". This is helpful in order to avoid creasing of the film.
• Fig. 1 should be understood as an unfolded representation.
• this film is efficiently air cooled right at the exit from the nip. This can conveniently be carried out by applying an air die which ends in a wall of microporous material, localised immediately after the nip and with this wall parallel with and almost touching the film.
• the angle (v) can easily be calculated on trigonometric basis.
• each of these 4 rollers may be coated with a soft rubber, and the two rollers (1) may not form a nip against each other.
• the roller pair (2) may form a nip, but should exert almost zero nip pressure. Having left these pulling rollers, the film (A) may be spooled up or may proceed directly to the lamination, which e.g. may take place as shown in Fig. 3.
• the thin film (B) has been coextruded and thereby supplied with a lower melting lamination layer. It may be oriented in any direction but preferably substantially perpendicular to the m.d. It may come from a reel or directly from a t.d. stretching apparatus such as a conventional tenter frame.
• the direction of orientation in (B) is not necessarily about 90° to the m.d. but should conveniently not be lower than about 40°. Such angles of orientation can be formed by helical cutting of an m.d. oriented tube
• the fine grooves limit the bonding to a fine pattern of bonding lines with unbonded spaces between.
• the pitch(es) of the pattern of grooves may be as low as 0.3 mm as it appears from the microphoto.
• the thin film (B) becomes almost instantly heated to the temperature selected for lamination. If (B) consists of HDPE, LLDPE, LDPE or crystalline PP, supplied with a lower melting lamination layer, a suitable temperature will be between about 80-110 0 C depending on the lamination layer, and if film (B) is in strongly oriented state in the t.d., it must have been properly stabilised at a similar or higher temperature before it is fed to the apparatus, to avoid transverse shrinkage. Such stabilisation is described in WO04/54793 (Rasmussen) in connection with Fig. 5.
• the film (B) is laminated with film (A) as this comes out of the "Segmental Rollers” stretching process supplied with longitudinally extending flutes.
• Film (A) is also supplied with a lower melting lamination layer.
• the two pairs of pulling rollers (1) and (2) in Fig. 1 are in the Fig. 3 substituted by 3 rollers (10) all coated by a soft rubber, and all driven at the same velocity, which is adjusted as explained in connection with Fig. 1. They have ambient temperature.
• the line bonding takes place when the two films meet on laminating roller (9).
• Film (A) is not heated before meeting film (B).
• film (A) still has the same longitudinal tension as when it left the "Segmental Rollers".
• To preserves its fluted shape it only follows the hot laminating roller over a short adjustable arc, e.g. about 20°. Thereby only a small portion of each flute is flattened and heated.
• the lamination of (A) and (B) passes over a pressurised air film, formed through microporous material on the air die (1 1 ).
• the air has ambient temperature and acts to cool and lubricate the films.
• the tension in the laminate is maintained by the two driven pull-rollers (12) and the idling nip roller (13). Both rollers (12) are coated with a soft rubber, and (13) is coated with foam rubber.
• the three pull rollers (10), the laminating roller (9) and the two pull rollers (12) are all driven with the same circumferential velocity, and thus film (A) is still under a high longitudinal tension when it meets nip roller (13). Having left the nip (A) relaxes on its way to winding, while the unbonded spaces in (B) bend and form flutes, provided all adjustments are correct.
• EXAMPLE 1 A 3-layer tubular PE film is extruded from a 1.5 mm circular exit slot, with blow-up ratio (BUR) 2:1 and in gauge 0.017 mm.
• the composition is as follows: Middle layer, 60% of total: plain high mol. wgt. HDPE,
• Outer surface layer an ethylene copolymer starting melting at 80 0 C,
• Inner surface layer plain LLDPE of melt flow index 1.
• the low ultimate stretching ratio is due to a high melt orientation in the starting film.
• This high melt orientation is an advantage for the invention, and without this it might have been necessary to pre-orient the film, in conventional manner e.g. at 70 0 C.
• the obtained waving appears from the microphoto Fig. 4. As already mentioned the waving is surprisingly even.
• the film can be laminated under a low lamination pressure with a film (B) having similar composition without ruining the waves.
• film (B) before the laminating process started as a 60° melt oriented film in form of a 55 mm wide ribbon.
• the 60° orientation was achieved by helical cutting of an m.d. melt oriented tube, as this is described in
• Roller (8) was not yet tried as a nip roller as in Fig. 3. It acted as an idle roller positioned at some distance from the laminating roller (9).
• the air-film cooling device in Fig. 3 was substituted by a simple metal block, which at the start of each trial run had about ambient temperature. It needed not be cooled since each trial run was short.
• the diameter of the laminating roller (9) was 32 mm, and its length was 52 mm. With reference to Fig. 1 , the angle u was 17° and the angle v was 60°, both like in Example 1.
• Outer surface layer (for lamination) was 15% of total and consisted of an ethylene copolymer of melting point about 80-90 0 C (Attane SL4102).
• the gap of the exit slot in the coextrusion die was 1.5 mm and the blowup ratio was 1.8:1.
• the unwinding tension in film (B) was adjusted to make the flutes in film (B) as deep as possible.
• Film (A) became fluted with wavelength 0.5 mm and depth of flutes 0.23 mm.
• Film (B) became fluted with a wavelength corresponding to the pitch on roller (9) and depth of flutes 0.09 mm.
• Example 2 of gauges 0.030 mm and 0.015 mm, respectively.
• transverse melt orientation of film (B) was tried. In an industrial process this can conveniently be achieved by the method described in US5361469 (Rasmussen) col. 4 In 39-col. 5 In 6. This technology has already been briefly described in the general description of the present invention. However, in the present trial 55 mm wide strips were simply cut out of the extruded tubular film under 90° to its m.d., and several such strips, were joined by means of adhesive tape.
• Film (A) became fluted with wavelength 0.5 mm and depth of flutes 0.01 mm.
• Film (B) became fluted with wavelength corresponding to the pitch on roller (9) and depth of flutes 0.045 mm,

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Shaping By String And By Release Of Stress In Plastics And The Like (AREA)
• Laminated Bodies (AREA)
• Lining Or Joining Of Plastics Or The Like (AREA)
• Extrusion Moulding Of Plastics Or The Like (AREA)

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• 2009
  • 2009-07-17 GB GBGB0912449.6A patent/GB0912449D0/en not_active Ceased
• 2010
  • 2010-07-14 CN CN2010800378655A patent/CN102548733A/zh active Pending
  • 2010-07-14 JP JP2012520030A patent/JP2012533444A/ja not_active Withdrawn
  • 2010-07-14 WO PCT/EP2010/060168 patent/WO2011006942A1/en not_active Ceased
  • 2010-07-14 AU AU2010272530A patent/AU2010272530A1/en not_active Abandoned
  • 2010-07-14 EP EP10743063A patent/EP2454079A1/de not_active Withdrawn
  • 2010-07-16 TW TW099123469A patent/TW201107118A/zh unknown

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