Composite laminate for forming luggage articles

Abstract

To provide an improved plastic laminate material that is thin, lightweight, strong, and impact-resistant. [Solution] The laminate includes a first set of BOPP films, at least one of which includes a film having a thermoplastic polymer core and at least one outer layer of thermoplastic polymer. The laminate includes a second set of BOPP films, each of which includes a co-extruded film having a thermoplastic polymer core and at least one outer layer of thermoplastic polymer. The laminate includes at least one woven plastic material sheet disposed between the first set of BOPP films and the second set of BOPP films. The laminate includes at least one matrix layer disposed on at least one side (e.g., the top side or the outward-facing side) of one or more sheets of the at least one woven plastic material sheet.

Description

[Technical Field]

[0001] Hard-sided luggage cases offer durability and support by forming the case exterior from relatively rigid, moldable materials. One drawback of these materials is that they are difficult to manufacture and mold, and have low tolerance for slight variations in the manufacturing and molding processes. The inflexibility of such materials is particularly evident when manufacturing deep-drawn articles. Luggage shells or cases manufactured from these materials may need to be relatively thick and / or relatively heavy to achieve the desired strength. In addition to the materials, the manufacturing and molding processes can also be costly, and these processes can be time-consuming. [Background technology]

[0002] Documents that may be relevant to this disclosure in that they include various approaches to materials for luggage articles include U.S. Patent No. 8,052,913, U.S. Patent No. 11,135,756, and European Patent No. 3455063. International Publication No. 2022 / 263585 discloses a moldable and tear-resistant polymer composite. This composite includes an outer polymer woven fabric layer arranged around a core of oriented polymer film and bonded thereto via an adhesive. This composite is moldable for luggage and the like. However, these approaches may be improved. [Overview of the project]

[0003] Embodiments described herein relate to a luggage shell formed from a laminate comprising a plurality of sets of biaxially oriented polypropylene (BOPP) films, at least one woven plastic material sheet (e.g., a self-reinforced polypropylene sheet), and at least one matrix layer positioned above the at least one woven plastic material sheet.

[0004] This disclosure provides, in particular, an improved plastic laminate material that is thin, lightweight, strong, and impact resistant. This material is versatile and suitable for deep drawing into articles such as luggage shells. Luggage shells constructed from this laminate are lightweight, thin, durable, resistant to deformation, and have excellent impact resistance and resilience during use and handling.

[0005] In one embodiment, a luggage shell formed by a laminate is disclosed. The laminate comprises a first set of biaxially oriented polypropylene (BOPP) films, at least one of the first set of BOPP films comprising a film having a thermoplastic polymer core and at least one outer layer of a thermoplastic polymer, both of which may be co-extruded. The laminate comprises a second set of BOPP films, each of which comprises a co-extruded film having a thermoplastic polymer core and at least one outer layer of a thermoplastic polymer. The laminate comprises at least one woven plastic material sheet disposed between the first set of BOPP films and the second set of BOPP films. The laminate comprises at least one matrix layer disposed on at least one side of one or more sheets of the at least one woven plastic material sheet, for example, the upper side or the outward side.

[0006] BOPP film includes at least one thermoplastic polymer layer that is stretched more in one of the transverse and mechanical directions (e.g., longitudinal direction) than in the other transverse and mechanical direction. The stretched film is called a biaxially oriented polypropylene film and provides higher strength and melting point than an identically formulated unstretched film.

[0007] At least one woven plastic material sheet may include a self-reinforced polypropylene (SRPP) sheet, which includes an oriented (e.g., stretched) polypropylene tape woven to form a fabric with improved strength and heat resistance in the mechanical direction of the tape compared to a nonwoven layer. Thus, the woven tape results in improved strength in both the mechanical and transverse directions of the resulting woven plastic material sheet and the laminate containing it.

[0008] In some examples, the luggage shell further comprises a third set of BOPP films positioned between a first set of BOPP films and a second set of BOPP films. In such examples, at least one woven plastic material sheet includes a first woven plastic material sheet positioned between a first set of BOPP films and a third set of BOPP films, and a second woven plastic material sheet positioned between a second set of BOPP films and a third set of BOPP films.

[0009] In some examples, at least one matrix layer includes a first matrix layer positioned on the upper or outward side of the first woven plastic material sheet, a second matrix layer positioned on the lower or inward side of the first woven plastic material sheet, and a third matrix layer positioned on the upper or outward side of the second woven plastic material sheet.

[0010] At least one matrix layer enables strong bonding of woven plastic material sheets to adjacent layers, resulting in a strong bond, for example, between at least one woven plastic material sheet and an adjacent BOPP film. Woven plastic material sheets, such as SRPP material, are difficult to bond to other materials, such as polypropylene homopolymers or copolymers used in BOPP films.

[0011] In some examples, the luggage shell includes a first set of BOPP films having 1 to 10 BOPP films, a second set of BOPP films having 1 to 10 BOPP films, and a third set of BOPP films having 1 to 20 BOPP films.

[0012] In some examples, the luggage shell includes a first set of BOPP films comprising 3 to 5 BOPP films, a second set of BOPP films comprising 3 to 6 BOPP films, and a third set of BOPP films comprising 7 to 14 BOPP films, and at least one matrix layer comprising a first matrix layer positioned above the first woven plastic material sheet, a second matrix layer positioned below the first woven plastic material sheet, and a third matrix layer positioned above the second woven plastic material sheet.

[0013] In some cases, the luggage shell and laminate have a total thickness of 1.5 mm or less.

[0014] The laminates disclosed herein are relatively thin, yet provide excellent strength, impact resistance, resilience, and aesthetic appearance.

[0015] In some examples, the first set of BOPP films has a thickness of 5% to 15% of the total thickness of the laminate within the luggage shell.

[0016] In some examples, the second set of BOPP film has a thickness of 12% to 18% of the total thickness of the laminate within the luggage shell.

[0017] In some examples, the laminate includes a third set of BOPP films disposed between a first set of BOPP films and a second set of BOPP films. In such examples, the at least one woven plastic material sheet comprises: a first woven plastic material sheet disposed between the first set of BOPP films and the third set of BOPP films, a second woven plastic material sheet disposed between the second set of BOPP films and the third set of BOPP films, a third woven plastic material sheet disposed between the first woven plastic material sheet and the second woven plastic material sheet, and a fourth woven plastic material sheet disposed between the third woven plastic material sheet and the second woven plastic material sheet. In such examples, the at least one matrix layer comprises: a first matrix layer disposed on an upper side of the first woven plastic material sheet, a second matrix layer disposed on an upper side of the second woven plastic material sheet, a third matrix layer disposed on an upper side of the third woven plastic material sheet, and a fourth matrix layer disposed on an upper side of the fourth woven plastic material sheet.

[0018] In some examples, the third set of BOPP films has a thickness that accounts for 35% to 45% of the total thickness of the laminate for a luggage shell.

[0019] In some examples, the first set of BOPP films has a thickness that accounts for 5% to 15% of the total thickness of the laminate, the second set of BOPP films has a thickness that accounts for 12% to 18% of the total thickness of the laminate, and the third set of BOPP films has a thickness that accounts for 35% to 45% of the total thickness of the laminate.

[0020] In some examples, the at least one woven plastic material sheet has a thickness of less than 10% of the total thickness of the laminate for a luggage shell.

[0021] The thickness of the at least one woven plastic material sheet enables the laminate for a luggage shell to have strength, impact resistance and elasticity while being relatively thin and lightweight.

[0022] In some examples, at least one matrix layer includes a maleic anhydride-grafted polypropylene (MAPP) layer or a polypropylene film layer.

[0023] In some examples, at least one woven plastic material sheet includes at least one self-reinforced polypropylene (SRPP) sheet.

[0024] In some examples, at least one woven plastic material sheet includes multiple polypropylene tapes stretched longitudinally and arranged in a selected weave pattern, the selected weave pattern being visible through a first set of BOPP films.

[0025] In some examples, at least one woven plastic material sheet contains a colorant. In some examples, at least one matrix material contains a colorant.

[0026] In some examples, at least one matrix layer, at least one woven plastic material sheet, one or more of the first set of BOPP films and the second set of BOPP films, or any combination thereof, contains a colorant, the colorant being at least partially visible through the first set of BOPP films.

[0027] In some examples, the second set of BOPP films forms the inner surface of the laminate, and the innermost BOPP film of the second set of BOPP films is white, and the color intensity of the laminate viewed from its outermost surface is greater than that of an identical or similarly constructed laminate that does not include the white innermost BOPP film.

[0028] By arranging a substantially transparent or translucent BOPP film and matrix layer between the outer surface of the laminate and the top or outward-facing surface of at least one woven plastic material sheet, the aesthetic appearance of the laminate is selectively controlled to reveal the weave of at least one woven plastic material sheet. The colorant in at least one matrix layer may be at least partially transparent or translucent in order to reveal the weave of at least one woven plastic material sheet in its colored state.

[0029] In some examples, one or more handles are attached to at least one luggage shell, and multiple wheels are attached to at least one luggage shell.

[0030] In one embodiment, a method for manufacturing a luggage shell is disclosed. This method includes forming a layup relating to one of the laminates disclosed herein. This method may include laminating the layup under uniform pressure in an isobaric press. This method includes forming the laminated layup on a luggage shell using a plug cavity die.

[0031] The laminates disclosed herein are formed on a press under uniform pressure to prevent air bubbles, delamination, and degradation of physical properties (e.g., strength) in the resulting laminate and luggage shell. Furthermore, the laminates disclosed herein provide a material that can be easily deep-drawn in a mold to form a luggage shell with an excellent aesthetic appearance.

[0032] By using a polypropylene-based material for the film, the films in the laminate may bond to each other and possess complementary physical properties. Such a configuration provides the advantages disclosed above.

[0033] Features of any of the disclosed embodiments may be used in combination with each other without limitation. Furthermore, other features and advantages of this disclosure will become apparent to those skilled in the art by considering the following detailed description and accompanying drawings.

[0034] With understanding that these drawings only illustrate typical embodiments of the present invention and should therefore not be considered to limit the scope of the invention, embodiments of the present invention are described and explained in more specific and detail with reference to the following appended drawings. [Brief explanation of the drawing]

[0035] [Figure 1] Figure 1 is a cross-sectional view of a laminate for use in a luggage shell according to at least some embodiments. [Figure 2] Figure 2 is an isometric view of a partially disassembled BOPP film according to at least some embodiments. [Figure 3] Figure 3 is an isometric view of a partially disassembled extruded tape according to at least some embodiments. [Figure 4] Figure 4 is an isometric section of a woven plastic material sheet according to at least some embodiments. [Figure 5] Figure 5 is a schematic diagram of a double belt press according to at least some embodiments. [Figure 6A] Figure 6A is an isometric view of a molding apparatus according to at least some embodiments. [Figure 6B] Figure 6B is a perspective view of a sheet gripping rack according to one embodiment. [Figure 6C] Figure 6C is a perspective view of the gripping bar of a gripping rack according to one embodiment. [Figure 7A] Figure 7A is a front isometric view of a luggage shell according to at least some embodiments. [Figure 7B] Figure 7B is an isometric view of the rear of a luggage shell according to at least some embodiments. [Figure 7C] Figure 7C is an isometric view of a hard-side luggage case according to at least one embodiment. [Figure 8] Figure 8 is a flowchart of a method for manufacturing a luggage shell according to at least some embodiments. [Figure 9A] Figure 9A is a graph showing the results of a rigidity test of an exemplary luggage shell in the mechanical direction. [Figure 9B] Figure 9B is a graph showing the results of a rigidity test of an exemplary luggage shell in the lateral direction. [Figure 10A] Figure 10A is a graph showing the results of an exemplary luggage shell elasticity test in the mechanical direction. [Figure 10B] Figure 10B is a graph showing the results of an exemplary luggage shell elasticity test in the lateral direction. [Figure 11A] Figure 11A is a graph showing the results of the bending modulus test in the mechanical direction. [Figure 11B] Figure 11B is a graph showing the results of the bending modulus test in the transverse direction. [Figure 12] Figure 12 is a graph showing the results of the T-type peel test. [Figure 13] Figure 13 is a graph showing the results of an additional T-type peel test. [Figure 14] Figure 14 is a graph of the temperature profile of Example 1. [Modes for carrying out the invention]

[0036] Embodiments described herein relate to luggage shells formed from a laminate having a plurality of sets of BOPP films and at least one sheet of woven plastic material. This disclosure provides improved laminate materials for luggage shells and improved luggage shells constructed from such materials. In particular, this disclosure provides a laminate that is lightweight, resilient (e.g., dent-resistant), impact-resistant, versatile, and suitable for deep drawing. Generally, the material consists of a set of plastic films laminated together. Luggage shells constructed from this material are lightweight, thin, durable, deformation-resistant, and resilient. The suitability of the material for deep drawing helps in the production of luggage shells that are substantially wrinkle-free, including in corner areas, and, individually or in combination, helps in producing a high-quality surface finish. Where used herein, the term "~consists of" may mean "includes" or "contains".

[0037] This disclosure provides a method for producing a laminate that is strong, resilient, and aesthetically pleasing. The disclosure also provides a method for producing a luggage shell from an improved material, which is relatively easy, quick, and inexpensive. This material may be heated, tensioned, and deep-drawn to produce the luggage shell.

[0038] Figure 1 is a cross-sectional view of a laminate 100 for use in a luggage shell according to at least some embodiments. The laminate 100 includes a set of polypropylene film layers. In some examples, the laminate 100 includes a first set of BOPP films 110, a second set of BOPP films 120, at least one woven plastic material sheet (e.g., SRPP) 130 or 150 disposed between the first set of BOPP films 110 and the second set of BOPP films 120, and at least one matrix layer 140 or 142 disposed on at least one side of the at least one of the woven plastic material sheets 130 and 150, for example, the top or outward-facing surface or side. The laminate has an outer surface 102 that faces outward (shown upward in Figure 1) toward the observer or the outer surface of the luggage shell. The laminate 100 includes an inner surface 104 that faces away from the observer or forms the inner surface of the luggage shell. At least one woven plastic material sheet 130 and 150 is located inside the laminate 100, for example, between the outer surface 102 and the inner surface 104.

[0039] As shown in Figure 1, in some examples, the laminate 100 includes a third set of BOPP films 180 positioned between a first set of BOPP films 110 and a second set of BOPP films 120. In such examples, the laminate 100 includes both a first woven plastic material sheet 130 positioned between the first set of BOPP films 110 and the third set of BOPP films 180, and a second woven plastic material sheet 150 positioned between the second set of BOPP films 120 and the third set of BOPP films 180. Each woven plastic material sheet includes at least one corresponding matrix layer 140 or 142 on at least one side thereof, such as the top. Furthermore, the woven plastic material sheets 130 and 150 may each independently include a matrix layer 141 or 143 on their opposite side.

[0040] As will be described in detail below, each set of BOPP films 110, 120, or 180 includes at least one layer of oriented thermoplastic film, and in the example, multiple layers or each layer of each set of BOPP films 110, 120, or 180 are oriented thermoplastic film. At least one woven plastic material sheet 130 and 150 may include longitudinally stretched polypropylene tape woven in at least two directions (e.g., warp and weft) to form a polymer woven fabric. At least one matrix layer 140-143 may include a polymer film (e.g., polypropylene) configured to bond to at least one woven plastic material sheet and BOPP film material placed between them.

[0041] The individual film layers of the laminate 100 may be joined to each other to form the laminate 100. Such film layers may be formed separately and then combined to form a layup (e.g., a laminated film, sheet, and layered sheet), and this layup may be formed before joining the film layers to form the laminate 100, or at the same time as joining. Although illustrated with 15 film layers, the laminate 100 may include at least 8 film layers, for example, 8 to 15 film layers, 10 to 18 film layers, 15 to 25 film layers, 25 to 50 film layers, 25 or fewer film layers, or 20 or fewer film layers.

[0042] The laminate 100 may have a thickness of 3 mm or less, for example, about 0.9 mm to about 1.5 mm, about 0.93 mm to about 1.23 mm, about 1.5 mm to about 2.5 mm, about 2 mm or less, about 1.5 mm or less, about 1.3 mm or less, about 1.20 mm or less, about 1.15 mm or less, or a thickness greater than 0.5 mm. The laminate 100 has a minimum weight of about 0.7 g / m². 2 It may have a weight of, for example, about 0.7 g / m 2 ~Approx. 3.0g / m 2 , about 0.7g / m 2 ~Approx. 1.3g / m2 , about 1.0 g / m 2 to about 1.2 g / m 2 , about 1.2 g / m 2 to about 1.8 g / m 2 , about 1.8 g / m 2 to about 2.5 g / m 2 , about 2.5 g / m 2 less than, about 1.5 g / m 2 less than, about 1.2 g / m 2 may have a weight of less than the above values. The relatively thin and light laminate 100 provides excellent rigidity, excellent dent resistance, and excellent deep draw formability during molding.

[0043] Individual film layers of the laminate 100 have similar or diverse properties and characteristics to impart selected rigidity, aesthetic appearance, weight, resilience (dent resistance), versatility, and deep draw formability to the resulting laminate 100. Various layers of the laminate 100 will be separately described below.

[0044] The first set of BOPP films 110 may include one or more BOPP films, or two or more BOPP films, for example, 1 to 10 BOPP films, 2 to 10 BOPP films, 3 to 5 BOPP films, 5 to 8 BOPP films, less than 10 BOPP films, or less than 5 BOPP films. For example, the first set of BOPP films 110 may include at least BOPP films 112, 114, and 118. The first set of BOPP films 110 may have a total thickness of about 50 µm or more, for example, a total thickness of about 50 µm to about 250 µm, about 80 µm to about 120 µm, about 120 µm to about 180 µm, about 180 µm to about 250 µm, less than 250 µm, or less than 150 µm. For example, the first set of BOPP films 110 may have a thickness of about 100 µm. The first set of BOPP films 110 may have a thickness accounting for 5% to 15% of the total thickness of the laminate 100. The thicknesses of each of BOPP films 112, 114, or 118 may be the same or different from each other. BOPP films 112, 114, or 118 may differ from each other in other properties such as material composition and surface treatment.

[0045] At least a portion of the BOPP films 112, 114, or 118 (e.g., each film) may include a core layer of a biaxially oriented thermoplastic polymer and an outer layer of at least one thermoplastic polymer. Figure 2 is an isometric view of a partially exploded BOPP film 200 according to at least some embodiments. The BOPP film 200 may be used independently as the BOPP films 112, 114, or 118 (Figure 1) of the first set of BOPP films 110. As used herein, “film” is a structure comprising at least one individual layer of a continuous sheet. In this example, the BOPP film 200 includes at least one core layer 202 and at least one outer layer 204. The at least one outer layer 204 may be located above 203, below 205, or both of the core 202. In some examples (not shown), the BOPP film 200 may not include at least one outer layer 204.

[0046] The core layer 202 is composed of a thermoplastic polymer. The thermoplastic polymer may be oriented in one or more directions, such as biaxial orientation. As used herein, a “biaxially oriented” film is a film stretched in two different directions, and includes, in non-limiting examples, being stretched in the transverse and mechanical directions (e.g., longitudinal directions). A biaxially oriented film may, in example, be stretched to 12 times the original transverse dimensions of the unstretched film (e.g., 6 to 10 times or 9 times) and to 10 times the original mechanical dimensions of the unstretched film (e.g., 3 to 8 times or 4 to 6 times).

[0047] Examples of biaxially oriented thermoplastic polymers include biaxially oriented polypropylene homopolymer (BOPP), polyamide (BOPA), polyester (BOPET), polyvinyl alcohol (BOPVA), polylactic acid (BOPLA), and polyethylene (BOPE). In one embodiment, the core layer 202 is made of BOPP.

[0048] At least one outer layer 204 is composed of an oriented or unoriented heat-sealable material. In some examples, at least one outer layer 204 is substantially polypropylene (PP) alone. In some examples, at least one outer layer 204 is composed of a copolymer (binary copolymer) of PP and polyethylene (PE). Polyethylene may constitute up to about 5% of the copolymer. In some examples, the outer layer 204 is composed of a terpolymer (ternary copolymer) of PP, PE, and polybutene (PB). Polyethylene and polybutene together may constitute up to about 5% of the terpolymer. Any of the biaxially oriented thermoplastic polymer materials disclosed herein may be formed at least partially from recycled materials, for example, containing at least 10% (e.g., at least 75% or at least 90%) recycled PP.

[0049] In some examples, the core 202 and at least one outer layer 204 may comprise compatible or complementary polymers, thereby allowing the core 202 and at least one outer layer 204 to be co-extruded. For example, the core 202 and at least one outer layer 204 may be composed of thermoplastic polymers. In some examples, the core 202 is composed of oriented polypropylene homopolymer (OPP), and at least one outer layer 204 is composed of a copolymer of PP and PE. In some examples, the core 202 is composed of oriented polypropylene homopolymer, and at least one outer layer 204 is composed of a thermopolymer of PP, PE, and polybutene. In some examples, the core 202 is composed of a PP polymer, and at least one outer layer 204 is composed of a PP polymer or a PP / PE copolymer. The core 202 may have a melting point of about 150°C to about 190°C, for example, about 170°C.

[0050] At least one outer layer 204 has a lower melting point than the core 202. At least one outer layer 204 may have a melting point of about 110°C to about 135°C, for example, about 130°C. The difference between the melting point of the core 202 and the melting point of at least one outer layer 204 may be about 10°C to about 60°C, or about 10°C to about 50°C, or about 10°C to about 40°C, or about 10°C to about 30°C, or about 10°C to about 20°C. A larger difference in melting points between the core 202 and the outer layer 204 (e.g., 60°C instead of 5°C) may be useful in manufacturing laminates with improved mechanical and / or physical properties (e.g., a one-piece structure in which film layers are joined together). A larger difference in melting points may allow lamination at a temperature that melts at least one outer layer 204 but not the core 202. As the processing temperature approaches the melting point of the core 202, the core 202 begins to soften, and the molecules of the core 202 may lose their orientation. This can result in reduced physical and mechanical properties of the resulting laminate 210 compared to a laminate 210 in which the core 202 is not melted or softened. Laminates formed with a softened core are still suitable for use and may be included in the examples disclosed herein.

[0051] A difference in melting point between the core 202 and at least one outer layer 204 of approximately 10°C or more may make it easier to laminate a set of films 200 together. If the processing temperature is high enough to melt or partially melt at least one outer layer 204, but the core 202 is not melted, the layers of BOPP film 200 may slide against each other, or adjacent BOPP film 200 may slide against each other, when forming the laminate. The mechanical properties of the laminate are best maintained by substantially not melting the core 202 during the manufacture of the laminated sheet. However, in another example, if the core 202 softens or partially melts during the manufacture of the laminate, the mechanical properties may be reduced, but still sufficient for further use. The difference in melting points may also make the process of forming the laminate easier. This is because the melting or partial melting of at least one outer layer 204 and the melting, partial melting, or softening of the core 202 give the laminate plasticity.

[0052] At least one outer layer 204 defines an outer surface 206 and an inner surface 208 adjacent to and engaging with the BOPP film 200. The outer surface 206 may be corona-treated, which may impart sufficient wettability and adhesion to the BOPP film 200 for subsequent printing, lamination, or coating of the BOPP film 200. For example, at least one outer layer 204 may have its outer surface 206 corona-treated for better adhesion to the film directly adjacent to it. For example, the outer surface 206 of the outermost film in the first set of films 110 may be corona-treated.

[0053] The core 202 and at least one outer layer 204 may be co-extruded to form a BOPP film 200. In contrast to woven fabrics, in which yarns or tapes are woven in two directions (warp and weft) to form a plastic fabric, the BOPP film 200 is manufactured by the co-extrusion of multiple layers. For example, the BOPP film 200 is manufactured by co-extruding at least one outer layer 204 and the core 202.

[0054] Specific BOPP films 200 suitable for use with the first set of BOPP films 110 may include KXE heat-sealable BOPP film having a PP outer layer and a BOPP core (available from TATRAFAN, sro in Slovakia), ONXE BOPP film having a PP outer layer and a BOPP core (available from TERICHEM, as in Slovakia), KXHSS heat-sealable BOPP film having a polypropylene outer layer and a BOPP core (available from TATRAFAN, sro in Slovakia), and the like.

[0055] BOPP film 200 may have a thickness of approximately 10 μm to 100 μm, approximately 10 μm to 30 μm, approximately 30 μm to 50 μm, approximately 40 μm, approximately 20 μm, or less than approximately 40 μm. BOPP film 200 has a basis weight (square weight) of approximately 0.015 g / m². 2 ~about 0.04g / m 2 It may be approximately 0.015 g / m², for example. 2 ~about 0.020g / m 2 , about 0.020g / m 2 ~about 0.030g / m 2 , about 0.030g / m 2 ~about 0.040g / m 2 , about 0.034g / m 2 ~Approx. 0.037g / m 2 , or 0.040 g / m 2 It may be less than [a certain value]. The BOPP film 200 may be transparent, translucent, or opaque. For example, the BOPP film 200 (e.g., core 202) may be translucent or opaque white. In some examples, the BOPP film 200 may be a color other than white. In some examples, only the core layer is colored, whether it is another color or white.

[0056] Various versions of the BOPP film 200 may be used to form the laminate 100, such as multiple layers having the same properties, multiple layers having different properties, or both. Returning to Figure 1, each of the BOPP films 112, 114, and 118 of the first set of BOPP films 110 may be similar or identical to each other independently in one or more embodiments, such as material composition and thickness. For example, in one or more embodiments, BOPP films 112 and 114 may be identical to each other, and BOPP film 118 may be different from BOPP films 112 and 114. Similarly, in one or more embodiments, BOPP films 114 and 118 may be identical to each other, and BOPP film 112 may be different from BOPP films 114 and 118. In some examples, the first set of BOPP films 110 may include five BOPP films, with two additional BOPP films positioned between BOPP film 114 and BOPP film 118. In the overall example, BOPP films 114, 118 and additional BOPP films may include KXE (e.g., KXE-S1, KXE-40, or other KXE films) heat-sealable BOPP films, and BOPP film 112 may include ONXE BOPP film. In such an example, fewer or additional BOPP films may be used, for example, to provide the laminate 100 with a selected thickness or weight. Many combinations of the number of BOPP films, material types, thicknesses, weights, etc., may be used to form the first set of BOPP films 110. The outermost BOPP film 112 may have a selected finish on its outermost surface, such as a glossy finish, a matte finish, or a satin finish.

[0057] The first set of BOPP films 110 may form the outer surface 102 of the laminate 100. For example, BOPP film 112 may form the outermost surface 102 of the laminate 100. Thus, in some examples, the first set of BOPP films 110 may include at least a sufficient number of individual BOPP films to impart a selected surface finish (such as a smooth finish) to the outer surface of the laminate, even if there is an underlying layer with varying thickness. For example, during lamination, unless the first set of BOPP films provides sufficient polymer material between the woven plastic material and the surface to fill in the variations in thickness of the underlying woven structure, the woven structure of the woven plastic material sheet, such as an SRPP sheet, may create texture on the surface of the laminate by print-through. In some examples, the appropriate number of BOPP films in the first set of BOPP films to produce a smooth surface of the laminate may be 3 to 5.

[0058] In one or more embodiments, the second set of BOPP films 120 may be similar to or identical to the first set of BOPP films 110 and 200. For example, each of the second set of BOPP films 120 may include a core of biaxially oriented thermoplastic polymer and at least one outer layer of thermoplastic polymer, as disclosed above with respect to the first set of BOPP films 110. In some examples, at least a portion of the second set of BOPP films 120 may not include at least one outer layer. The second set of BOPP films 120 may include a different number of film layers, thickness, material composition, etc., than the first set of BOPP films 110.

[0059] The second set of BOPP films 120 may include one or more BOPP films or at least two BOPP films, for example, one to ten BOPP films, twenty to ten BOPP films, three to six BOPP films, five to ten BOPP films, less than ten BOPP films, or less than five BOPP films. For example, the second set of BOPP films 120 may include BOPP films 122, 124, and 128.

[0060] In one or more embodiments, one or more of the BOPP films 122, 124, and 128 may be similar or identical to each other independently. For example, in one or more embodiments, BOPP films 122 and 124 may be identical to each other, and BOPP film 128 may be different from BOPP films 122 and 124. Similarly, in one or more embodiments, BOPP films 124 and 128 may be identical to each other, and BOPP film 122 may be different from BOPP films 124 and 128. In some examples, the second set of BOPP films 120 may include four BOPP films with an additional BOPP film positioned between BOPP films 124 and 128. In such examples, BOPP films 122 and 124 may include KXE heat-sealable BOPP films, and the additional BOPP film and BOPP film 128 may include KXHSS heat-sealable BOPP films. In some examples, the second set of BOPP films 120 includes BOPP films 122 and 124 made of KXE heat-sealable BOPP film, and BOPP film 128 made of KXHSS heat-sealable BOPP film, and at least one additional BOPP film (placed between BOPP films 124 and 128). Many combinations of the number of BOPP films, the type of material, the thickness, the weight, etc., can be used to form the second set of BOPP films 120.

[0061] In some examples, the second set of BOPP film 120 may have a thickness of 10% to 25% of the total thickness of the laminate 100, for example, 12% to 18%, about 12% to about 15%, about 15% to about 20%, less than about 20%, or less than about 18% of the total thickness of the laminate 100.

[0062] The second set of BOPP films 120 may form the inner surface 104 of the laminate 100. For example, BOPP film 128 may form the innermost layer and inner surface 104 of the laminate 100. In some examples, the innermost BOPP film of the second set of BOPP films 120 may contain a colorant. For example, one or more of the innermost BOPP films (e.g., 122, 124, or 128) may be colored white. In such examples, the color of the laminate 100 as seen from the outermost surface will exhibit higher color intensity or brightness than in examples without the white innermost BOPP film.

[0063] The laminate 100 includes at least one woven plastic material sheet, such as an SRPP sheet, placed between a first set of BOPP films 110 and a second set of BOPP films 120. The at least one woven plastic material sheet may include one woven plastic material sheet, two woven plastic material sheets, three woven plastic material sheets, four woven plastic material sheets, at least five woven plastic material sheets, or fewer than five woven plastic material sheets. For example, the at least one woven plastic material sheet may include a woven plastic material sheet 130 (e.g., a first SRPP layer) and a woven plastic material sheet 150 (e.g., a second SRPP layer). The at least one woven plastic material sheet includes a thermoplastic tape arranged in a selected weave pattern. The selected weave pattern may be at least partially visible through the first set of BOPP films 110.

[0064] Each woven plastic material sheet includes one or more longitudinally stretched thermoplastic tapes woven into the sheet. Figure 3 is an isometric view of a partially disassembled extruded tape 300 according to at least some embodiments. As shown, the tape 300 may include a core layer 302 and at least one outer layer 304. In some examples, the tape 300 may include only the core layer 302. In some examples, the tape 300 may include only at least one outer layer 304 on one side of the core layer 302. The core layer 302 and at least one outer layer 304 may be provided as separate films and may be joined (e.g., bonded) to form the tape 300 by one or more of the following: co-extrusion, heating, etc. For example, the stretched polymer forming the core layer 302 may be co-extruded together with stretched or unstretched polymers forming at least one outer layer 304 on both sides of the core layer 302 to form the tape 300.

[0065] Suitable thermoplastic polymers for use in the core layer 302 include one or more of the following: polypropylene, polyethylene, polyamide, polyester, polyvinyl alcohol, polycarbonate, polylactic acid, polybutene, and acrylonitrile butadiene styrene (ABS). For example, the core 302 may contain a polypropylene homopolymer stretched to a selected degree. The core 302 may also contain copolymers such as PP / PE copolymers in which PE is a trace component (e.g., 5% or less). The core 302 may also contain terpolymers, quarterpolymers (quaternary copolymers), etc. Polypropylene may be the main component of the polymer forming the core 302.

[0066] The core 302 may, in one example, be stretched longitudinally (e.g., in the mechanical direction) to at least five times the original dimensions of the unstretched polymer film (e.g., 8 to 12 times, 12 to 15 times, less than 20 times, or 10 times). By stretching the thermoplastic polymer film longitudinally to form the core 302, the resulting core 302 has a higher melting temperature than the unstretched polymer film. The longitudinally stretched polymer film forming the core 302 also has higher strength and elasticity than the same unstretched polymer film.

[0067] At least one outer layer 304 is composed of an oriented or unoriented heat-sealable thermoplastic polymer, such as any of the thermoplastic polymers disclosed herein. In some examples, the outer layer 304 is composed of a homopolymer, such as substantially PP alone. In some examples, the outer layer 304 includes a copolymer of PP and PE. PE may constitute up to about 5% of the copolymer. In some examples, the outer layer 304 is composed of a thermopolymer. The compositional compatibility between the material of the core 302 and the material of at least one outer layer 304 results in strong bonding between each layer in the tape 300.

[0068] The core 302 and at least one outer layer 304 of the tape 300 contain compatible or complementary polymers, thereby allowing the core 302 and outer layer 304 to be co-extruded. For example, the core 302 and outer layer 304 may be composed of the same thermoplastic polymer. The orientation (e.g., stretching) of the polymer film in each layer may differ between the core 302 and the outer layer 304. In some examples, the core 302 is composed of a longitudinally stretched polypropylene homopolymer, and the outer layer 304 is composed of an unstretched polypropylene homopolymer. In some examples, the core 302 is composed of a longitudinally stretched polypropylene homopolymer, and the outer layer 304 is composed of an unstretched copolymer of polypropylene and polyethylene. Either the core 302 or at least one outer layer 304 material disclosed herein may be formed from recycled material, for example, at least 10% (e.g., at least 75% or at least 90%) of recycled PP.

[0069] The core 302 has a higher melting point than the outer layer 304. For example, the core 302 may have a melting point of about 150°C or higher, such as about 150°C to about 190°C or about 170°C. The outer layer 304 may have a melting point of about 110°C to about 135°C or lower, such as about 130°C. The difference between the melting points of the core 302 and the outer layer 304 may be about 10°C to about 60°C, about 10°C to about 50°C, about 10°C to about 40°C, about 10°C to about 30°C, or about 10°C to about 20°C. A larger difference in melting points between the core 302 and the outer layer 304 (e.g., 60°C instead of 5°C) may be useful in manufacturing laminates with improved mechanical and / or physical properties (e.g., a one-piece structure in which film layers are joined together). While not limited to any particular mechanism or mode of action, a larger difference in melting points may allow lamination at a temperature that melts the outer layer 304 but not the core 302. As the processing temperature approaches the melting point of the core 302, the core 302 may begin to soften, and the molecules of the core 302 may lose their orientation, which may result in reduced physical and mechanical properties of the resulting tape 300 compared to a tape 300 in which the core 302 is not melted or softened.

[0070] In some examples, the tape 300 may not include at least one outer layer 304. In such examples, the core 302, which has a higher melting point than the absent at least one outer layer 304, may not readily bond to the layer surrounding the tape 300 or the sheet formed therefrom (e.g., woven plastic material 400) due to the mismatch in melting temperatures between them. Therefore, while a tape 300 without at least one outer layer 304 may be used, a tape 300 with at least one outer layer 304 provides a stronger bond to the BOPP film and matrix layer disclosed herein.

[0071] The tape 300 may be transparent, translucent, or opaque. The tape 300 may contain a colorant in one or more of the core 302 or at least one outer layer 304. For example, a polypropylene film having a selected color may be used as at least one outer layer 304 to color the tape 300 and the resulting at least one woven plastic material sheet 130 or 150 (Figure 1). The colorant may be imparted to the tape 300 by a pigment added to the polymer therein, such as a white pigment in the polypropylene homopolymer. The colorant may enable the transparency, translucency, or opacity of the tape 300. Thus, at least one woven plastic material sheet containing the colored tape 300 contains a colorant. The colored tape 300 may be visible from its outer surface throughout the entire laminate.

[0072] The tape 300 may contain one or more fibers, such as within the core 302. For example, the warp and weft threads of the resulting woven plastic material sheet may independently contain one or more fibers such as aramid fibers, glass fibers, and carbon fibers.

[0073] Two or more tapes 300 are woven together to form a woven plastic material or woven fabric (e.g., an SRPP layer). Figure 4 is an isometric section of a woven plastic material sheet 400 according to at least some embodiments. As shown, the woven plastic material sheet 400 is formed from polymer tapes 402 and 404 woven in a selected weave pattern. In one or more embodiments, the polymer tape may be the same as or identical to tape 300. The woven plastic material sheet 400 may be in the form of an SRPP sheet.

[0074] In some examples, one or more warp or weft threads in a woven plastic material sheet may be made from tapes having a cumulative width of at least 110% of the dimensions (e.g., length or width) of the woven plastic material sheet, for example, at least 120%, at least 140%, at least 150%, 200% or less, or 160% or less. In some examples, the width of the warp or weft thread may be at least 1 mm, for example, 1 mm to 5 mm, 2 mm to 3 mm, 2.5 mm, or less than 5 mm. Overlapping tapes may improve the visibility of the weave within the laminate 100 and reduce the appearance of gaps or voids between the tapes.

[0075] The selected weave pattern may include twill weave (e.g., 2x2), plain weave, satin weave, rib weave, variegated weave, broken twill weave, 3x1 weave, or any variation thereof. In some examples, the weave pattern may provide a three-dimensional weave pattern designed to give the laminate 100 a selected texture or textured appearance. In some examples, a composite weave pattern may be used, for example, a weave pattern for producing a multilayer fabric, also called a three-dimensional weave pattern. In a composite weave pattern, multiple layers of warp and / or weft may be used. In some examples, the three-dimensional weave pattern may include three or more yarn systems corresponding to multiple layers of warp and / or weft. In other examples, one or more tapes may be twisted together to form one of the weft or warp. Such twisting may impart three-dimensional properties to the resulting woven plastic material. A three-dimensional pattern may be formed in the woven plastic material by using tapes twisted together in an arbitrarily selected pattern for one or more of the warp or weft.

[0076] At least one woven plastic material sheet may contain one or more colorants. For example, one or both of the (warp and weft) tapes 404 and 402 may contain a selected colorant. In some examples, the warp and weft of the woven plastic material may contain different colorants. In some examples, the weft may contain different colorants throughout the woven plastic material sheet, for example, alternating or randomly containing different colorants in tapes every other weft, every three tapes, every four tapes, every five tapes, etc. The warp may have different colorants throughout the woven plastic material sheet, for example, alternating colorants in tapes every other warp, every three tapes, every four tapes, every five tapes, etc. One or both of the warp or weft may contain one or more blocks of tapes of the same color, for example, containing at least five consecutive tapes of the warp or weft as a block. Therefore, at least one woven plastic material sheet 400, particularly the sheet closest to the outer surface of the laminate 100, may contribute at least part of the selected aesthetic appearance to the surface of the laminate 100.

[0077] In some examples, one or more warp or weft threads may contain fibers such as aramid fibers, carbon fibers, or glass fibers. The fibers may be arranged in alternating warp or weft tapes, tapes every three threads, tapes every four threads, or tapes every five threads in the woven plastic material sheet. In such examples, at least a portion of the warp or weft polypropylene tapes may be replaced by polymer tapes or fibers (e.g., high-performance polymer fibers or tapes) composed of or containing one or more of carbon fibers, aramid fibers, and glass fibers. Such tapes may include Endurmax® (ultra-high molecular weight polyethylene) hybrid or composite tapes (available from Teijin Aramid). In examples, the polymer fibers may be present in layers, such as within a woven sheet. In such examples, one of the four tapes may be a high-performance polymer fiber or tape, and in further examples, the warp tapes may contain high-performance polymer fibers or tapes. Alternatively, the high-performance polymer fibers or tapes may be contained within the woven sheet or form the entire woven sheet. Such woven sheets may form additional sheets (one or more) within the laminate layup. In such examples, a preferred tape may include a highly stretched polymer tape having fibers inside to facilitate recycling at the end of the product life.

[0078] In one or more embodiments, tapes 402 and 404 may be the same as or identical to tape 300. For example, tapes 402 and 404 may be co-extruded with a core layer having a higher melting point than at least one outer layer, which may result from the core layer being stretched in the longitudinal direction (e.g., the machine direction) while at least one outer layer is not stretched.

[0079] Tapes 402 and 404 are woven in two directions to form a plastic woven fabric. As shown in the figure, tape 402 is shown as a weft (e.g., a tape extending transversely to the longitudinal axis of the woven plastic material sheet 400), and tape 404 is shown as a warp (e.g., a tape extending along the longitudinal axis of the woven plastic material sheet 400). By having a longitudinally stretched core layer in each of the tapes 402 and 404 extending in mutually orthogonal warp and weft directions, at least one woven plastic material sheet 400 obtained has higher strength and resilience than a woven fabric without a stretched core in the tapes.

[0080] Suitable woven plastic material sheets 400 include Torodon® SRPP woven fabric (available from Don & Low in Forfar, Scotland, UK) and Tegris® woven fabric (available from Milliken Textiles in Ghent, Belgium).

[0081] At least one woven plastic material sheet 400 has a thickness of at least 100 μm, for example, about 100 μm to about 250 μm, about 100 μm to about 150 μm, about 130 μm to about 180 μm, about 50 μm to about 200 μm, less than about 200 μm, or about 160 μm. In some examples, at least one woven plastic material sheet 400 has a thickness of less than about 10% of the total thickness of the laminate 100 (Figure 1) or the layup forming it. For example, at least one woven plastic material sheet 400 may individually have a thickness of about 1% to about 10% of the laminate or the layup forming it. The woven plastic materials 130 or 150 may be the same or different from each other when at least two sheets are used in the laminate. For example, the weave used for one woven plastic material sheet may be different from the weave used for the other plastic material sheets. In another example, the stretching of each core layer 302 in a single woven plastic material sheet may differ from the stretching of other plastic material sheets. Differences between the woven plastic material sheets 130 and 150 may result in improvements in strength and elasticity properties.

[0082] A matrix layer may be used to provide a strong bond between at least one woven plastic material sheet 130 or 150 and an adjacent BOPP film, and to prevent delamination between them.

[0083] In some examples, at least one woven plastic material may include one or more polymer films placed on (e.g., above) the weave of tapes 404 and 402.

[0084] Returning to Figure 1, the laminate 100 includes at least one matrix layer 140 or 142, each located on one side (e.g., the top or outward side) of one or more sheets of at least one woven plastic material sheet 130 or 150. In some examples, at least one matrix layer 140 or 142 is present only on the top or outward side of at least one woven plastic material sheet 130 or 150. The laminate may further include at least one matrix layer 141 or 143 located on one or more opposite sides (e.g., the bottom or inward side) of at least one woven plastic material sheet 130 and 140. For example, at least one matrix layer may include a (first) matrix layer 140 positioned above the first woven plastic material sheet 130, a (second) matrix layer 141 positioned below the first woven plastic material sheet 130, and a (third) matrix layer 142 positioned above the second woven plastic material sheet 150. In some examples, a (fourth) matrix layer 143 is positioned below the second SRPP layer 150.

[0085] At least one matrix layer is formulated to provide additional matrix material and enhance adhesion between the BOPP film and the woven plastic material. At least one matrix layer is formulated to bond or adhere to at least one woven plastic material sheet 130 or 150 to a BOPP film (e.g., a first set of BOPP films, a second set of BOPP films, or a third set of BOPP films). At least one matrix layer 140-143 may be provided in the form of a film layer, or in some examples, a plurality of film layers. At least one matrix layer 140-143 may contain an adhesive or material configured to bond the film or layer in contact with it. For example, at least one matrix layer 140-143 may contain a polypropylene layer, a maleic anhydride grafted polypropylene (MAPP) layer, or another grafted polypropylene layer, or a polypropylene / polyethylene copolymer layer. In some examples, at least one matrix layer may be formulated to melt completely, partially, or not melt at all in response to heat applied to it during lamination or the like. At least one portion of one matrix layer may be configured to melt at the same melting temperature range as the outer layer of the woven plastic material 130 and the outer layer of the BOPP film (e.g., the outer layer (partially melted) or the entire film (e.g., completely melted)). Such melting temperatures may be about 110°C to 140°C, or about 130°C, as disclosed herein. The MAPP layer is particularly effective for bonding to the BOPP film and the woven plastic material (e.g., SRPP woven fabric). Suitable MAPP materials may include Rayotec MAPP 020 NT (available from AMCOR, Zurich, Switzerland) and Lamiten® film (available from Chemosvit Folie, Czech Republic).A polypropylene film layer suitable for use as at least one matrix layer may include blown PP film or cast PP film, for example, polypropylene film manufactured by Nitto Advanced Films Ltd. in Gronau, Germany. At least one matrix film may contain one or more layers. For example, a MAPP film may contain up to five layers of MAPP material.

[0086] At least one of the matrix layers 140-143 may contain a colorant. For example, at least one matrix layer 140 may contain a substantially transparent or translucent colorant. In such an example, at least one matrix layer may alter the aesthetic appearance or coloration of the laminate, for example, by enhancing the color of the colorant in at least one woven plastic material. In some examples, at least one matrix layer 140 may contain a substantially opaque colorant. In such an example, at least one matrix layer 140 may include areas without colorant, for example, to provide a cutout that allows the underlying at least one woven plastic material to be seen. The cutout may give the appearance of the laminate 100 and the luggage shell formed therefrom a selected pattern (e.g., checkerboard pattern), design, logo, text, etc.

[0087] Each of at least one matrix layer 140-143 may be at least about 10 μm thick, for example, about 10 μm to about 50 μm, about 10 μm to about 30 μm, about 20 μm to about 40 μm, about 30 μm to about 50 μm, less than about 50 μm, or less than about 30 μm. In some examples, the total thickness of all at least one matrix layer 140-143 may be less than about 10% of the total thickness of the laminate or the layup used to form it.

[0088] Returning to Figure 1, the laminate 100 may include a third set of BOPP films 180. The third set of BOPP films 180 may be placed between the first set of BOPP films 110 and the second set of BOPP films 120. For example, the third set of BOPP films 180 may be placed between at least one woven plastic material sheet 130 and at least one woven plastic material sheet 150. In such an example, at least one woven plastic material sheet 130 (e.g., a first SRPP layer) is placed between the first set of BOPP films 110 and the third set of BOPP films 180, and at least one woven plastic material sheet 150 (e.g., a second SRPP layer) is placed between the third set of BOPP films 180 and the second set of BOPP films 120.

[0089] In one or more embodiments, the third set of BOPP films 180 may be similar to or identical to the first set of BOPP films 110 and 200. For example, each of the third set of BOPP films 180 may include a core of biaxially oriented thermoplastic polymer and at least one outer layer of thermoplastic polymer, as disclosed above with respect to the first set of BOPP films 110 and 200. In some examples, at least a portion of the third set of BOPP films 180 may not include at least one outer layer. The third set of BOPP films 180 may include one or more different numbers of film layers, thicknesses, material compositions, etc., from those of the first set of BOPP films 110 and the second set of BOPP films 120.

[0090] The third set of BOPP films 180 may include one or more BOPP films or at least two BOPP films, for example, 1 to 20 BOPP films, 1 to 7 BOPP films, 7 to 14 BOPP films, 14 to 22 BOPP films, less than 20 BOPP films, less than 15 BOPP films, 11 BOPP films, or 9 BOPP films. For example, the third set of BOPP films 180 may include BOPP films 182, 184, and 188.

[0091] In one or more embodiments, one or more of the BOPP films 182, 184, and 188 may be similar or identical to each other independently. For example, in one or more embodiments, BOPP films 182 and 184 may be identical to each other, and BOPP film 188 may be different from BOPP films 182 and 184. Similarly, in one or more embodiments, BOPP films 184 and 188 may be identical to each other, and BOPP film 182 may be different from BOPP films 184 and 188. In some examples, the third set of BOPP films 180 may include a total of seven BOPP films, including four additional BOPP films placed between BOPP films 184 and 188. In some examples, the third set of BOPP films 180 may include a total of nine BOPP films, including six additional BOPP films placed between BOPP films 184 and 188. In some examples, the third set of BOPP films 180 may include a total of 11 BOPP films, including 8 additional BOPP films placed between BOPP films 184 and BOPP films 188. In some examples, the third set of BOPP films 180 may include a total of 13 BOPP films, including 10 additional BOPP films placed between BOPP films 184 and BOPP films 188. In some examples, the third set of BOPP films 180 may include a total of 14 BOPP films, including 11 additional BOPP films placed between BOPP films 184 and BOPP films 188. In such examples, BOPP films 182-188 may include KXE heat-sealable BOPP films, and the additional BOPP films and BOPP film 188 may include KXE heat-sealable BOPP films. The third set of BOPP films 180 may be formed using any combination of the number of BOPP films, the type of material, the thickness, the weight, etc.

[0092] In some examples, the third set of BOPP film 180 may have a thickness of about 25% to about 55% of the total thickness of the laminate 100, or it may have a thickness of about 25% to about 35%, about 30% to about 40%, about 35% to about 45%, less than about 40%, or less than about 35% of the total thickness of the laminate 100.

[0093] It should be recognized that the laminate 100 may contain more or fewer layers than those disclosed in Figure 1. For example, more or fewer BOPP films, woven plastic material sheets, or matrix layers may be used than those shown in Figure 1. Although not shown in Figure 1, in some examples the laminate 100 may contain one or more additional layers. For example, a carbon fiber-containing layer, an aramid fiber-containing layer, or a glass fiber-containing layer may be placed in the laminate as an intermediate layer. More or fewer woven plastic material sheets may be used than those shown in Figure 1.

[0094] In some examples, the laminate may include two or more woven plastic material sheets in combination with a first set of BOPP films 110, a second set of BOPP films 120, and a third set of BOPP films 180 positioned between the first set of BOPP films 110 and the second set of BOPP films 120. In such an example, at least one woven plastic material sheet may include a first woven plastic material sheet 130 positioned between a first set of BOPP films 110 and a third set of BOPP films 180, a second woven plastic material sheet 150 positioned between a second set of BOPP films 120 and a third set of BOPP films 180, a third woven plastic material sheet 130 positioned between the first woven plastic material sheet 130 and the second woven plastic material sheet 150 (for example, adjacent to the first woven plastic material sheet 130), and a fourth woven plastic material sheet 150 positioned between the third woven plastic material sheet 130 and the second woven plastic material sheet 150 (for example, adjacent to the second woven plastic material sheet 130). In such examples, at least one matrix layer may include a (first) matrix layer 140 positioned above the first woven plastic material sheet 130, a (second) matrix layer 142 positioned above the second woven plastic material sheet, a third matrix layer positioned above the third woven plastic material sheet 130, and a fourth matrix layer positioned above the fourth woven plastic material sheet 150. In some examples, only the first woven plastic material sheet 130 and the fourth woven plastic material sheet 150 may each have a matrix layer on top of them (for example, only on their upper side). In some examples, the second woven plastic material sheet 150 and the third woven plastic material sheet 130 may each have a matrix layer underneath them. In some examples, all of the woven plastic material sheets 130 and 150 may each have a matrix layer on top of them (for example, on one or more of their upper and lower sides).

[0095] In some examples, the laminate 100 may include at least one intermediate layer positioned between or in place of at least one layer of woven plastic material 130. The at least one intermediate layer may include a layer of woven or nonwoven material having aramid fibers, carbon fibers, or glass fibers within it. Suitable intermediate layers may include Endurmax® (ultra-high molecular weight polyethylene) hybrid or composite materials (available from Teijin Aramid Corporation).

[0096] The layup or laminate 100 used to form the laminate 100 may have selected dimensions, such as at least 30 cm in one or more of the width (e.g., transverse direction) and length (e.g., machine direction), and selected dimensions include, for example, 30 cm to 150 cm, 50 cm to 80 cm, 70 cm to 100 cm, 100 cm to 125 cm, 120 cm to 150 cm, 30 cm to 60 cm, 60 cm to 80 cm, 55 cm to 75 cm, 69 cm, 81 cm, 86 cm, 95 cm, 96 cm, 125 cm, less than 125 cm, less than 100 cm, or any combination thereof.

[0097] In some examples, individual layers (e.g., sheets, films, or layers) may be oriented in the same direction, for example, by aligning the machine direction of each layer in a single direction. In such examples, none of the individual layers may be oriented at an angle (e.g., orthogonal) to any other layer of the laminate with respect to its machine direction. Such a configuration limits or reduces the lateral stretching of individual layers. In other examples, individual layers (e.g., sheets, films, or layers) may be oriented at an angle to an adjacent layer located above or below them.

[0098] In some examples, a textile or fabric layer may be placed on the inner surface 104 of the laminate 100 for the luggage shell formation process, for example, as a lining for the finished luggage shell. The textile or fabric layer may be woven or composed of a composite material that has at least some degree of elasticity. In such examples, the additional layer may be co-extruded together with the other layers during the formation process of the laminate 100, or bonded to the inner surface 104 after lamination. The latter example can prevent lamination defects introduced by the textile layer.

[0099] In some examples, starting from the outermost layer, the laminate 100 may include a first set of BOPP films beginning with an ONXE BOPP film followed by four KXE BOPP films. A first matrix layer (e.g., PP or MAPP film) may be placed on at least one first woven plastic material sheet (e.g., Torodon® fabric) and positioned below the first set of BOPP films. A second matrix layer (e.g., PP or MAPP film) may be placed below at least one first woven plastic material sheet. A second set of BOPP films positioned below the second matrix layer may include eleven BOPP films (e.g., KXE films), and a third matrix layer (e.g., PP or MAPP film) may be placed below the second set of BOPP films. At least one second woven plastic material sheet (e.g., Torodon® fabric) may be placed below the third matrix layer. The third set of BOPP films may be placed beneath at least one second woven plastic material sheet, and the third set of BOPP films may include four BOPP films (e.g., two KXE BOPP films on top of two KXHSS BOPP films). An optional fourth matrix layer (e.g., PP or MAPP) may be placed between the third set of BOPP films and at least one second woven plastic material sheet.

[0100] In the above example, the third set of BOPP films may include three KXE BOPP films, and the KXHSS BOPP film may be absent. In such an example, the laminate 100 may include a lower matrix layer positioned below the third set of BOPP films, the lower matrix layer may be, for example, a PP or MAPP matrix layer. Such a lower matrix layer facilitates bonding of further layers (e.g., linings) to the laminate 100. Although not shown, the lower matrix layer may be present in any laminate disclosed herein.

[0101] It should also be understood that the laminate 100 shown in Figure 1 may also be a layup containing the same layers as described with respect to Figure 1 before the individual layers are joined together.

[0102] The laminate 100 may be formed by laminating a set of films (e.g., 110, 130, 140-143, 180, 150, 120) under selected pressure, temperature, and / or time conditions. The laminate 100 may be formed using a laminating machine such as an isobaric or isothermal press. The pressurizing device may include opposing oil cushions separated by a gap. As used herein, “bar” generally refers to, but not limited to, the surface pressure generated by the press. As used herein, “kN / m” generally refers to, but not limited to, the linear pressure generated by the press. Examples disclosed herein have shown that isobaric presses are particularly effective in significantly reducing or eliminating air bubbles that are typically present in samples prepared using isochoric presses.

[0103] Figure 5 is a schematic diagram of a double belt press 500 according to at least some embodiments. The double belt press 500 includes a lower press assembly 510 and an upper press assembly 520, between which a layup may be pressed, heated, and joined to form a laminate. The double belt press may include an isobaric press or an isothermal press.

[0104] The lower press assembly 510 includes a lower belt 511 and a lower pressure module 530 including a lower pressure body 531, the lower pressure body 531 having a set of thermal elements 532, 534, and 536 thermally connected thereto. The lower pressure module 530 may be adjustable to bias the lower belt 511 toward or toward the upper press assembly 520.

[0105] The thermal elements 532, 534, and 536 enable a combination of heating and / or cooling along the longitudinal length of the lower pressure module 530, thereby forming a laminate thereon.

[0106] The upper press assembly 520 includes an upper belt 521 and an upper pressure module 540 including an upper pressure body 541, the upper pressure body 541 having a set of thermal elements 542, 544, and 546.

[0107] The thermal elements 542, 544, and 546 enable heating and / or cooling along the longitudinal length of the lower pressure module 530, thereby forming a laminate thereon.

[0108] The formation of the laminates disclosed herein may involve the application of one or more temperatures and / or pressures. For example, in a double belt press 500, one or more temperature profiles may be used along the longitudinal length of the belts therein. In some examples, one or more temperatures or pressures applied by the double belt press may be constant along its longitudinal length. The pressure P1 may be less than about 100 bar, and may be, for example, about 10 bar to about 90 bar, about 10 bar to about 30 bar, about 25 bar to about 70 bar, about 60 bar to about 90 bar, about 30 bar to about 80 bar, about 60 bar to about 80 bar, about 50 bar to about 70 bar, or less than about 80 bar. In one example, the pressure is constant during the process, and in some examples, it is constant during any heating and cooling stages. The pressure may be about 30 bar to about 80 bar, preferably about 70 bar.

[0109] The individual film layers of the laminate 100 are laid up and heated to a selected temperature in a double belt press 500 and pressed at a selected pressure to form the laminate 100. The laminate 100 may be further processed to form a luggage shell, for example, a container shell or panel. For example, the laminate may be used in a molding apparatus to form a luggage shell or the like.

[0110] Figure 6A is an isometric view of a molding apparatus 640 according to at least some embodiments. The molding apparatus 640 may include a lining feeder 642, a press 644, and a heater array 646. In some examples, the lining feeder 642 receives and distributes textile sheets, such as mesh, knit, woven, or nonwoven fabric, for molding together with the sheets of laminate 100 (Figure 1). The textile sheets may function as the interior lining of the luggage shell produced by the molding apparatus 640. The textile sheets may be contained and stored in a tray 648 before being distributed to the sheets of laminate 100.

[0111] The press 644 includes an upper table 650 and a lower table 652. The upper table 650 may support an upper mold, which may be a male mold 654 of a deep drawing tool 656. In Figure 6, a portion of the upper table 650 is removed to more clearly show the male mold 654. The lower table 652 may support a lower mold, which may be a female mold 658 of a deep drawing tool 656. The tables 650 and 652 are movable relative to each other. The molds 654 and 658 are complementary to each other, so that one mold, e.g., a male mold 654, fits at least partially into the other mold, e.g., a female mold 658. Some clearance may be provided between the molds to ensure the thickness of the molded product. The molds 654 and 658 may be configured to produce luggage shells, container shells, panels, etc.

[0112] The press 644 further includes a sheet gripping rack 664. The rack 664 is configured to controllly hold the sheets of each laminate 100 in a position between the male mold 654 and the female mold 658. The rack 664 may also be configured to stretch or apply tension to the sheets of the laminate 100. Applying tension or pressure may help to further integrate the films of the laminate 100. The tension or pressure applied to the laminate 100 may be less than about 5 bar, for example, about 0.5 bar to about 4 bar, about 0.5 bar to about 3 bar, about 0.5 bar to about 2 bar, or about 1.5 bar to about 2 bar.

[0113] Figure 6B is a perspective view of a sheet gripping rack 664 according to one embodiment. Figure 6C is a perspective view of a gripping bar 665 of the gripping rack 664 according to one embodiment. As shown in Figure 6B, the gripping rack 664 may include an upper gripping bar 631 and a lower gripping bar 632 for gripping a laminated material or luggage shell, a support rod 612 for supporting the layup or laminated material, and one or more jaw motion drive units 633. The jaw motion drive units 633 that drive the upper gripping bar 631 and the lower gripping bar 632 (or jaws) in response to the respective process controls via a coupling mechanism (e.g., a toggle lever mechanism) may be operated on an electric, pneumatic, or hydraulic basis.

[0114] Therefore, the sheet gripping rack 664 is configured to support and grip the laminated material or the formed luggage shell before, during, and after pressure is applied to the laminated material. The sheet gripping rack 664 is also configured to apply a selected amount of tension to the laminated material (e.g., a sheet) or luggage shell during processing in the press 644. In some examples, no tension is applied, and the sheet gripping rack 664 simply holds the laminated material.

[0115] Returning to Figure 6A, the sheets of the laminate 100 may be introduced into the press 644 from the sheet supply section at the rear of the press 644 (as seen in Figure 6A). The laminate 100 is held between the male die 654 and the female die 658 by the sheet gripping rack 664. The upper and / or lower sides of the laminate may be heated, for example, while the laminate is being gripped and / or stretched by the sheet gripping rack 664.

[0116] The heater array 646 may heat the laminate 100 while the sheets are held between the male and female molds 654, 658. The laminate 100 (or layup) may be heated to a temperature high enough to melt, partially melt, or soften one or more of the outer layer 204, core 202, matrix layers 140-143, and at least one woven plastic material sheet 130 or 150 (Figure 1). The laminate 100 may be preheated and / or heated to a temperature of about 40°C to about 190°C, for example, about 40°C to about 90°C, about 40°C to about 70°C, about 70°C to about 110°C, about 110°C to about 190°C, about 125°C to about 150°C, about 135°C to about 160°C, or about 150°C to about 190°C, less than about 190°C, or less than about 120°C. In some examples, if the laminate 100 is not clamped or otherwise held during preheating, it may be particularly useful to preheat at a temperature lower than the shrinkage temperature of the material within the laminate 100. For example, the preheating temperature may be around 50°C to 60°C.

[0117] Press 644 is configured to quickly align or close dies 654, 658, which may help reduce the number of wrinkles that occur in the corner portions of deep-drawn articles such as luggage shells. Dies 654, 658 may remain in the closed position for approximately 15–45 seconds, approximately 15–30 seconds, approximately 30–45 seconds, approximately 20–35 seconds, approximately 30–45 seconds, less than approximately 1 minute, less than approximately 40 seconds, or approximately 30 seconds.

[0118] The molding apparatus 640 may output a luggage shell or the like, including a laminate 100 (Figure 1). Figure 7A is an isometric front view of a lid shell 722 of a luggage shell 720 according to at least some embodiments. Figure 7B is an isometric rear view of a base shell 734 or luggage shell 720 according to at least some embodiments, which together form a luggage case 750 (see Figure 7C). The luggage shell 720, such as a suitcase shell, may be composed of the laminate 100 disclosed herein. The luggage shell 720 may be in the form of a lid shell 722 (Figure 7A) or a base shell 734 (Figure 7B).

[0119] Any one or more of the sides may include surface features 748. Features 748 may be concave regions such as grooves 747 and convex regions such as ribs 749. In addition to aesthetic appeal, features 748 may provide rigidity or resistance to bending or straining forces acting on the shells 720, 734.

[0120] One or both of the lid shell 722 and the base shell 734 may be deep-drawn such that the depth of the lid shell 722 or the base shell 734 is very large relative to its length or width.

[0121] Any luggage shell described herein may be used to form the body of a luggage case, such as a hard-side luggage case. Figure 7C is an isometric view of a hard-side luggage case 750 according to at least one embodiment. The hard-side luggage case 750 is defined by a operably coupled lid shell 722 and base shell 734 to form a housing 752 having an outer layer. Either or both of the lid shell 722 and the base shell 734 may be manufactured by any of the aforementioned methods.

[0122] The luggage case 750 may also include a closure mechanism such as a zipper, defining a closure line 770 that divides the luggage case 750 into a lid shell 722 and a base shell 734. A hinge (not shown) for pivotally connecting the lid shell 722 and the base shell 734 together is located along the closure line 770. The closure mechanism may include latches, buttons, straps, etc.

[0123] The luggage case 750 may also include two or more wheels 772, one or more carry handles, and a retractable pull handle (not shown).

[0124] Luggage cases having different surface features and aesthetic appearances may be manufactured using the laminates disclosed herein. For example, a luggage case having a substantially flat surface may be manufactured using laminate 100.

[0125] Figure 8 is a flowchart of a method 800 for manufacturing a luggage shell according to at least some embodiments. Method 800 includes a step 810 for forming a layup, a step 820 for stacking the layups in a press under constant pressure, and a step 830 for forming the stacked layups into a luggage shell. Method 800 may include more or fewer steps than steps 810-830. For example, any of steps 810-830 may be divided into a smaller set of steps. In some examples, Method 800 may include assembling the luggage shell into luggage.

[0126] Step 810, forming a layup, may include forming a layup relating to any of the laminates disclosed herein. For example, a layup may include one or more of the following, as disclosed herein: a first set of BOPP films, a second set of BOPP films, a third set of BOPP films, at least one woven plastic material sheet, and at least one matrix layer. Forming a layup may include arranging the film layers in any of the orders disclosed herein. For example, forming a layup may include combining individual film layers into a layup by feeding the film from each roll in a continuous feed or batch feed process, such as using a double belt press. The layup may have any of the layup or laminate properties disclosed herein, such as composition, thickness, or melting point.

[0127] Step 820 of laminating the layup under uniform pressure in a press may include exposing the layup to a selected pressure or temperature for an arbitrary duration in an isobaric double-belt press. For example, a pressure of 10 bar to about 90 bar (e.g., 30 bar to about 70 bar) may be applied along with a first temperature of at least 90°C to about 180°C to at least partially melt or soften one or more components of the layup. Laminating the layup under uniform pressure may further include cooling the laminate to a second temperature lower than the first temperature (e.g., to ambient temperature) to allow the film layers in the layup to cool and bond together, thereby forming the laminate 100.

[0128] Laminating the layup under uniform pressure may include feeding the layup into an isobaric press at a selected feed rate, such as any of the feed rates disclosed herein. Laminating the layup may also include forming the laminate 100 (Figure 1) using an isobaric press in any of the methods disclosed herein.

[0129] Step 830, forming a laminated layup into a luggage shell using a plug cavity mold, may include supplying one of the laminates disclosed herein to a molding apparatus 640 (Figure 6). Forming a laminated layup into a luggage shell using a plug cavity mold may include forming the luggage shell using a molding apparatus in any of the methods disclosed herein. For example, forming a laminated layup into a luggage shell using a plug cavity mold may include holding and / or applying tension to the laminate using a sheet gripping rack, heating the laminate, or pressing the laminate in the mold cavity by any of the pressures disclosed herein. A plug cavity mold includes a deep drawing mold having male and female mold halves.

[0130] Forming the laminated layup on the luggage shell may involve using other molding or forming techniques such as hydraulic molding, extrusion molding, or manual processing.

[0131] Forming a stacked luggage shell may further include using the luggage shell to form luggage such as wheeled luggage. Wheeled luggage may have one or more wheels, one or more handles 774, one or more telescopic handles 774, and at least one closing mechanism (e.g., a zipper, clip, strap, or button). In such examples, forming luggage using the luggage shell may include assembling opposing luggage shells, attaching one or more closing mechanisms, attaching a set of wheels, attaching one or more hinges, or attaching one or more straps, telescopic handles, etc., to form any of the luggage disclosed herein.

[0132] Laminates having woven plastic material sheets disclosed herein offer superior physical properties such as rigidity, tensile strength, fracture strain, and high joint strength, with a relatively thin construction, compared to similar laminates without woven plastic material sheets. Furthermore, laminates having woven plastic material sheets disclosed herein have higher rigidity and elasticity compared to similar laminates without woven plastic material sheets. To demonstrate the advantages of the laminates disclosed herein, laminates according to examples were formed and tested. [Examples]

[0133] Example 1:

[0134] A laminate was formed according to Table 1 below, and this was designated as Example 1. The laminate of Example 1 was formed by isobaric pressing.

[0135] [Table 1]

[0136] Comparative example A:

[0137] A laminate was formed according to Table 2 below and designated as Comparative Example A. The laminate of Comparative Example A was formed by isobaric pressing.

[0138] [Table 2]

[0139] Comparative example B:

[0140] A laminate was formed according to Table 3 below, and this was designated as Comparative Example B. The laminate of Comparative Example B was formed by isobaric pressing.

[0141] [Table 3]

[0142] Comparative example C:

[0143] A laminate was formed according to Table 4 below, and this was designated as Comparative Example C. The laminate of Comparative Example C was formed by isobaric pressing.

[0144] [Table 4]

[0145] The laminates of Example 1, Comparative Example A, Comparative Example B, and Comparative Example C (see Table 4 above) had similar thicknesses. Tests were conducted on Example 1, Comparative Example A, Comparative Example B, and Comparative Example C to determine their physical properties (e.g., mechanical properties). Specifically, tensile tests, impact tests, stiffness tests, elasticity tests, peel tests, and three-point bending tests were performed on each example.

[0146] The laminates relating to Example 1, Comparative Example A, and Comparative Example B were subjected to the tensile and elasticity tests described below.

[0147] Four samples from each of Example 1, Comparative Example A, and Comparative Example B were cut into rectangles of the same size (25 mm × 250 mm). Tensile tests were performed on the samples according to ASTM D3039, "Standard Test Method for Tensile Properties of Polymer Matrix Composites." The samples were tested in an Instron 5985 testing machine equipped with a 30 kN load cell. The samples were secured in the testing machine using mechanical vice grips (e.g., clamps). Sandpaper was used as end tabs for the samples to prevent slippage within the mechanical vice grips. The samples were tested at a gauge length of 150 mm. The strain rate was 6% / min.

[0148] Based on the results of tensile tests, tensile strength, stress, strain, and elastic properties were calculated.

[0149] The mean surface strain was calculated using digital image correlation. The tensile modulus was calculated as the slope of the stress-strain curve for strains of 0.1% to 0.3%. Elasticity was calculated as the area under the strain-stress curve up to the yield point. The yield point was determined by the 0.2% offset method. Tensile strength is the highest point on the stress-strain curve, and the corresponding strain is the fracture strain.

[0150] Figures 9A and 9B are graphs showing the results of the tensile modulus (Young's modulus) tests for each example in the mechanical and transverse directions, respectively. As shown in Figure 9A, Comparative Example A (labeled CEA in Figures 9A to 10B) had the lowest tensile modulus in the mechanical direction, with a Young's modulus (E) of approximately 2.5 gigapascals (GPa). Example 1 (labeled WE1 in Figures 9A to 10B) had a higher tensile modulus in the mechanical direction than Comparative Example A, with an E value of approximately 2.8 GPa. Comparative Example B (labeled CEB in Figures 9A to 10B) had the highest tensile modulus in the mechanical direction, with an E value of approximately 3.1 GPa. As shown in Figure 9B, Comparative Example B had the lowest tensile modulus in the transverse direction, with an E value of approximately 3.1 GPa. Example 1 had a higher tensile modulus in the transverse direction than Comparative Example B, with an E value of approximately 4.3 GPa. Comparative Example A had the highest tensile modulus in the transverse direction, with an E value of approximately 4.7 GPa.

[0151] Figures 10A and 10B are graphs showing the results of the elasticity tests in the mechanical and transverse directions for each example, respectively. Each example was tested according to the protocol disclosed above with respect to the tensile tests summarized in Figures 9A and 9B, and the elasticity properties obtained from the tensile tests are also as described above. Elasticity is an indicator of the amount of energy that a material can absorb without undergoing plastic deformation or permanent deformation. As shown in Figure 10B, Comparative Example B has the lowest transverse elasticity, with an elasticity of approximately 0.08 MJ / m 3 As a result, Example 1 has higher lateral elasticity than Comparative Example B, with an elasticity of approximately 0.17 MJ / m 3 Comparative Example A exhibited the highest lateral elasticity (slightly higher than Example 1), with an elasticity of approximately 0.18 MJ / m². 3 As shown in Figure 10A, Comparative Example B had the lowest elasticity in the mechanical direction, with an elasticity of approximately 0.8 MJ / m 3 Comparative Example A has higher lateral elasticity than Comparative Example B, with an elasticity of approximately 0.14 MJ / m². 3 In Example 1, the lateral elasticity was the highest, with an elasticity of approximately 0.16 MJ / m 3 Example 1 exhibited the highest overall elasticity (in both directions) and was superior to the comparative example material in terms of elasticity or "actual" impact resistance.

[0152] Three-point bending tests (used to calculate flexural modulus properties) were performed according to the ASTM D7264 standard, "Flexural properties of polymer matrix composites." For each example's laminate, five rectangular samples measuring 13 mm × 50 mm were formed and tested in both the mechanical and transverse directions. The three-point bending tests were performed using an Instron 5943 testing machine equipped with a 100 N load cell.

[0153] Figures 11A and 11B are graphs showing the results of the flexural modulus tests in the mechanical and transverse directions, respectively. As shown in Figure 11A, Comparative Example B had the highest flexural modulus in the mechanical direction, with a flexural modulus of approximately 3.3 GPa. Example 1 had a higher flexural modulus in the mechanical direction than Comparative Example A, with a flexural modulus of approximately 2.4 GPa. Comparative Example A had the lowest flexural modulus in the mechanical direction, with a flexural modulus of approximately 1.8 GPa. As shown in Figure 11B, Comparative Example A had the lowest flexural modulus in the transverse direction, with a flexural modulus of approximately 2.9 GPa. Comparative Example B had a higher flexural modulus in the transverse direction than Comparative Example A, with a flexural modulus of approximately 3.2 GPa. Example 1 had the highest flexural modulus in the transverse direction, with a flexural modulus of approximately 3.6 GPa. The relatively high flexural modulus (e.g., stiffness) of Example 1 allows for greater design flexibility in cases using the laminate of Example 1 (e.g., suitcases) compared to the comparative examples. For example, the more rigid material in Example 1 avoids the need for a specific geometric configuration used for structural rigidity.

[0154] Additional tests were conducted to investigate the effects of adding more than two layers of woven plastic material sheets to the laminate. For example, flexural modulus and tensile strength tests were performed on laminates with two and four woven plastic material sheets according to Example 1. The flexural modulus and tensile strength (e.g., stiffness) tests showed that there was virtually no difference in flexural stiffness and strength in the lateral direction of the laminate, and only a slight increase in flexural stiffness and strength in the mechanical direction. However, even the increase observed when using four woven plastic material sheets was not as large as the increase in flexural stiffness and strength observed when using two sheets compared to when no woven plastic material sheets were used. Therefore, a decrease in return can be expected when adding more than two layers of woven plastic material sheets to the laminate.

[0155] The test results showed that Example 1 maintained good tensile strength and bending properties in both the mechanical and transverse directions, and maintained excellent elasticity in both the mechanical and transverse directions. Therefore, luggage shells made from the laminate of Example 1 are expected to provide lightweight yet strong, durable, and dent-resistant luggage.

[0156] The laminates of Example 1, Comparative Example A, and Comparative Example B were formed into luggage having the same structure and dimensions. The laminates of Example 1, Comparative Example A, and Comparative Example B were formed on an isobaric press and finally molded into upper (e.g., front) and lower (e.g., rear) luggage shells in a cavity plug mold and assembled into a suitcase. The laminates of Example 1, Comparative Example A, and Comparative Example B had substantially similar thicknesses. For each example, the weights of the upper and lower shells were recorded.

[0157] [Table 5]

[0158] As shown in Table 5, the luggage shells formed in Example 1, Comparative Example A, and Comparative Example B also had nearly the same weight.

[0159] Compression tests were performed on luggage formed from the laminates according to Example 1, Comparative Example A, Comparative Example B, and Comparative Example C to determine the rigidity of each example. Such tests determine the sturdiness (e.g., rigidity) of the luggage when force is applied to the top of the assembled luggage case, such as when a user is standing on the top panel (e.g., sitting on it).

[0160] The laminated luggage units in Example 1, Comparative Example A, Comparative Example B, and Comparative Example C had the same structure, dimensions, and components (e.g., wheels and zippers). Carry handles, logos, and pull handles were not attached to each example. For testing, each luggage unit was placed on a tensile testing machine with its wheels in contact with a flat surface and the zippers connected between the two shells. A load of 50 Newtons was first applied to the luggage unit, and at this point, the displacement was recorded as zero to avoid the influence of small deformations already occurring in the luggage shells of each example. The compressive force was then gradually increased until a selected displacement was observed. The selected displacements were 8 mm, 16 mm, and 20 mm. For each example, the force required to achieve the selected displacement was recorded. The results of the stiffness test for each example are shown in Table 6 below.

[0161] [Table 6]

[0162] As shown in Table 6, Example 1 required the highest load for displacement at each increase in displacement, surpassing all other examples at a displacement level of 20 mm.

[0163] Therefore, at least some of the embodiments disclosed herein are more rigid than other laminates used in luggage.

[0164] In Example 1, peel tests were conducted by varying the combinations of SRPP material, BOPP material, matrix material, and the temperature at which the materials were bonded. Specifically, T-type peel tests were performed according to the ASTM D1876-08 standard.

[0165] For testing, for each material combination, ten rectangular samples measuring 250 mm × 20 mm with an unbonded side (e.g., end) length of 76 mm were cut from a 0.6 mm thick panel (except for two samples for the BOPP and PP combination bonded at 125°C). During sample preparation, a release film was inserted into the stack between the layers to be tested, leaving one side of the sample panel unbonded. The T-shaped portion of the sample combination was formed by clamping each material in opposition and pulling each material in opposite directions to measure the peel strength of the bond between the materials. These samples were tested on an Instron 5943 testing machine, gripping the ends and pulling them apart at a speed of 254 mm / min. Peel strength was calculated as the mean peel load after the first initial peak, normalized by width, according to the ASTM D1876-08 test procedure.

[0166] Specific sample combinations (SCs) were formed with various combinations of materials from adjacent layers of the stack at various bonding temperatures, including 125°C, 130°C, 140°C, and 150°C. Some of the sample combinations (SCs) were fabricated with a MAPP matrix layer instead of a PP matrix layer bonded to BOPP or SRPP. The SCs include the materials specified in Example 1. The materials for the SCs for the T-type peel test are listed in Table 7 below.

[0167] [Table 7]

[0168] Don & Rowe 1 and Don & Rowe 2 have different melting temperatures; Don & Rowe 1 has a melting temperature in the range of 140°C to 145°C, while Don & Rowe 2 has a melting temperature in the range of 125°C to 130°C.

[0169] Figure 12 is a graph showing the results of the T-type peel test. As shown in Figure 12, SC1 showed an average peel strength of approximately 0.78 Newtons / millimeter (N / mm), SC2 showed an average peel strength of approximately 0.56 N / mm, SC3 showed an average peel strength of approximately 0.78 N / mm, SC4 showed an average peel strength of approximately 0.67 N / mm, SC5 showed an average peel strength of approximately 0.78 N / mm, SC6 showed an average peel strength of approximately 0.50 N / mm, SC7 showed an average peel strength of approximately 0.87 N / mm, SC8 showed an average peel strength of approximately 0.46 N / mm, SC9 showed an average peel strength of approximately 0.87 N / mm, SC10 showed an average peel strength of approximately 0.72 N / mm, SC11 showed an average peel strength of approximately 0.67 N / mm, and SC12 showed an average peel strength of approximately 0.73 N / mm.

[0170] The results of the T-type peel test show the bond strength between materials in sample combinations SC1 to SC12 as peel strength. The result for SC8 shows that the direct bond between BOPP and SRPP is the weakest among the sample combinations, followed closely by the bond between SRPP and SRPP in SC6. The test result for SC10 shows that the bond between BOPP and PP is stronger than the bond between BOPP and SRPP (even at a relatively low temperature of 125°C). The bonds between SRPP and MAPP in SC11 and SC12 were also stronger than the bond between SRPP and SRPP in SC6 and the bond between SRPP and BOPP in SC8. Furthermore, the bonds between SRPP and PP in SC2, SC3, SC5, SC7, and SC9 were all stronger than the bond between SRPP and BOPP in SC8 and the bond between SRPP and SRPP in SC6. The bonds between BOPP and MAPP in SC1 and SC4 were also stronger than the bond between SRPP and BOPP and the bond between SRPP and SRPP.

[0171] Based on a T-type peel test, a PP film (PP or MAPP) between an SRPP fabric (Don & Row 1 or Don & Row 2) and a BOPP film increases the bonding strength between these materials compared to direct bonding between SRPP and BOPP.

[0172] The bonding between SRPP and PP in SC2, SC5, and SC9 showed an increase in strength with increasing bonding temperature. Similarly, the bonding between SRPP and PP in SC3 and SC7 also showed an increase in strength with increasing bonding temperature.

[0173] An additional T-type peel test was performed according to the method described in parentheses above.

[0174] Additional SCs were formed with various combinations of materials from adjacent layers of the stack at various bonding temperatures, including 125°C, 130°C, 140°C, 150°C, 155°C, 160°C, and 165°C. Some of the sample combinations (SCs) were made with a MAPP matrix layer instead of a PP matrix layer bonded to BOPP or SRPP. The SCs include the materials specified in Example 1. The materials for the SCs for the T-type peel test are listed in Table 7 below.

[0175] The SC materials for additional T-type peel tests are listed in Table 8 below.

[0176] [Table 8]

[0177] Figure 13 is a graph showing the results of an additional T-type peel test. As shown in Figure 13, SC13 showed an average peel strength of approximately 1.1 N / mm, SC14 showed an average peel strength of approximately 1.05 N / mm, SC15 showed an average peel strength of approximately 0.6 N / mm, SC16 showed an average peel strength of approximately 1.25 N / mm, SC17 showed an average peel strength of approximately 1.22 N / mm, SC18 showed an average peel strength of approximately 0.8 N / mm, SC19 showed an average peel strength of approximately 0.8 N / mm, SC20 showed an average peel strength of approximately 0.5 N / mm, and SC21 showed approximately 0. SC22 showed an average peel strength of 48 N / mm, SC23 showed an average peel strength of approximately 1.5 N / mm, SC24 showed an average peel strength of approximately 1.2 N / mm, SC24 showed an average peel strength of approximately 0.88 N / mm, SC25 showed an average peel strength of approximately 0.75 N / mm, SC26 showed an average peel strength of approximately 0.66 N / mm, SC27 showed an average peel strength of approximately 0.5 N / mm, SC28 showed an average peel strength of approximately 1.4 N / mm, and SC29 showed an average peel strength of approximately 0.45 N / mm.

[0178] The results of the additional T-type peel tests show the bond strength between materials in sample combinations SC13 to SC29 as peel strength. The results for SC21, SC27, and SC29 show that the direct bond between SRPP and BOPP is the weakest among the additional sample combinations, followed closely by the SRPP to SRPP bond in SC20. The test results for SC15 show that the bond between SRPP (Don & Rowe 2) and PP formed at 130°C is the next weakest. The bonds between BOPP and MAPP formed at 150°C in SC26, the MAPP bond formed at 150°C in SC24, and the SRPP to PP bond formed at 150°C in SC25 are stronger than the SRPP to BOPP bond. The BOPP to MAPP bond in SC18 and the SRPP to PP bond in SC19, both formed at 140°C, are approximately equivalent to the SRPP to MAPP bond formed at 150°C in SC25. The bonding of BOPP and MAPP in SC13 formed at 125°C, and the bonding of BOPP and BOPP in SC14 formed at 125°C, have higher bonding strength than SC15, SC18-SC21, SC24-SC27, and SC29.

[0179] The BOPP-to-PP bonds of SC13, SC17, and SC23, formed at 125°C, 140°C, and 150°C respectively, were stronger than all other tested bonds except for the BOPP-to-BOPP bonds. The BOPP-to-BOPP bonds of SC16, SC22, and SC28 were stronger than all other tested bonds.

[0180] Based on additional T-type peel tests, the PP film (PP or MAPP) between the SRPP fabric (Don & Rowe 2) and the BOPP film increases the bonding strength between these materials compared to direct bonding between SRPP and BOPP at all tested forming temperatures.

[0181] The bonding between SRPP and PP in SC15, SC18, and SC24 showed an increase in strength with increasing bonding temperature.

[0182] Figure 14 is a graph of the temperature profile of the laminate for WE1. The temperature profile used in the lamination process of WE1 has different temperatures across two zones in the isobaric press. Profile 1 has a temperature of 155°C in the first zone and 145°C in the second zone. Profile 2 has a temperature of 170°C in the first zone and 155°C in the second zone.

[0183] As used herein, the term “approximately” includes values ​​within ±5% of the value modified by the term “approximately.”

[0184] Where used herein, references to standards such as ASTM or ISO standards refer to the respective standards as of the filing date of this application.

[0185] The present invention may be embodied in other specific forms without departing from its spirit or essential features. The embodiments described should be considered in all respects to be illustrative and not limiting. Accordingly, the scope of the present invention is indicated not by the above description but by the appended claims. All modifications in the meaning and scope of the equivalents of the claims should be encompassed within their scope.

Claims

1. A luggage shell (720, 722, 734) formed by a laminate (100, 210), wherein the laminate (100, 210) is A first set of biaxially oriented polypropylene (BOPP) films, wherein at least one of the first set of BOPP films (110) comprises a co-extruded film comprising a thermoplastic polymer core (202, 302) and at least one outer layer (204) of a thermoplastic polymer, A second set of BOPP films (120), wherein at least one of the second set of BOPP films (120) comprises a thermoplastic polymer core (202, 302) and at least one outer layer (204) of a thermoplastic polymer, At least one woven plastic material sheet (130, 150, 400) is placed between the first set of BOPP films (110) and the second set of BOPP films (120), The system comprises at least one matrix layer (140, 141, 142, 143) disposed on at least one side of one or more sheets of the at least one woven plastic material sheet (130, 150, 400), Luggage shell.

2. The present invention further comprises a third set of BOPP films (180) positioned between the first set of BOPP films (110) and the second set of BOPP films (120), wherein the at least one woven plastic material sheet (130, 150, 400) is A first woven plastic material sheet (130, 150, 400) is placed between the first set of BOPP films (110) and the third set of BOPP films (180), The present invention includes a second woven plastic material sheet (130, 150, 400) positioned between the second set of BOPP films (120) and the third set of BOPP films (180), The luggage shell according to claim 1.

3. The luggage shell according to claim 2, wherein the at least one matrix layer (140, 141, 142, 143) includes a first matrix layer (140, 141, 142, 143) positioned above the first woven plastic material sheet (130, 150, 400), a second matrix layer (140, 141, 142, 143) positioned below the first woven plastic material sheet (130, 150, 400), and a third matrix layer (140, 141, 142, 143) positioned above the second woven plastic material sheet (130, 150, 400).

4. The first set of BOPP films (110) includes 1 to 10 BOPP films. The second set of BOPP films (120) includes 1 to 10 BOPP films. The third set of BOPP films (180) includes 1 to 20 BOPP films. The luggage shell according to claim 2 or claim 3.

5. The first set of BOPP films (110) includes 3 to 5 BOPP films. The second set of BOPP films (120) includes 3 to 6 BOPP films. The third set of BOPP films (180) includes 7 to 14 BOPP films. The at least one matrix layer (140, 141, 142, 143) includes a first matrix layer (140, 141, 142, 143) positioned above the first woven plastic material sheet (130, 150, 400), a second matrix layer (140, 141, 142, 143) positioned below the first woven plastic material sheet (130, 150, 400), and a third matrix layer (140, 141, 142, 143) positioned above the second woven plastic material sheet (130, 150, 400). A luggage shell according to any one of claims 2 to 4.

6. The present invention further comprises a third set of BOPP films (180) positioned between the first set of BOPP films (110) and the second set of BOPP films (120), wherein the at least one woven plastic material sheet (130, 150, 400) is A first woven plastic material sheet (130, 150, 400) is placed between the first set of BOPP films (110) and the third set of BOPP films (180), A second woven plastic material sheet (130, 150, 400) is placed between the second set of BOPP films (120) and the third set of BOPP films (180), A third woven plastic material sheet (130, 150, 400) is placed between the first woven plastic material sheet (130, 150, 400) and the second woven plastic material sheet (130, 150, 400), The present invention includes a fourth woven plastic material sheet (130, 150, 400) positioned between the third woven plastic material sheet (130, 150, 400) and the second woven plastic material sheet (130, 150, 400), The at least one matrix layer (140, 141, 142, 143) includes a first matrix layer (140, 141, 142, 143) positioned above the first woven plastic material sheet (130, 150, 400), a second matrix layer (140, 141, 142, 143) positioned above the second woven plastic material sheet (130, 150, 400), a third matrix layer (140, 141, 142, 143) positioned above the third woven plastic material sheet (130, 150, 400), and a fourth matrix layer (140, 141, 142, 143) positioned above the fourth woven plastic material sheet (130, 150, 400). The luggage shell (720, 722, 734) according to claim 1.

7. The first set of BOPP films (110) has a thickness of 5% to 15% of the total thickness of the laminate (100, 210). The second set of BOPP films (120) has a thickness of 12% to 18% of the total thickness of the laminate (100, 210). The third set of BOPP films (180) has a thickness of 35% to 45% of the total thickness of the laminate (100, 210). A luggage shell (720, 722, 734) according to any one of claims 2 to 6.

8. The luggage shell (720, 722, 734) according to any one of claims 1 to 7, wherein the at least one woven plastic material sheet (130, 150, 400) has a thickness of less than 10% of the total thickness of the laminate (100, 210).

9. The luggage shell (720, 722, 734) according to any one of claims 1 to 8, wherein the at least one matrix layer (140, 141, 142, 143) comprises a maleic anhydride grafted polypropylene (MAPP) layer or a polypropylene film layer.

10. The luggage shell (720, 722, 734) according to any one of claims 1 to 9, wherein the at least one woven plastic material sheet (130, 150, 400) comprises at least one self-reinforced polypropylene (SRPP) sheet.

11. The at least one woven plastic material sheet (130, 150, 400) includes a plurality of longitudinally stretched polypropylene tapes arranged in a selected weave pattern, The selected weave pattern is visible through the first set of BOPP films (110). A luggage shell according to any one of claims 1 to 10 (720, 722, 734).

12. One or more of the at least one matrix layer (140, 141, 142, 143), the at least one woven plastic material sheet (130, 150, 400), the first set of BOPP films (110), and the second set of BOPP films (120) contain a coloring agent. The coloring agent is at least partially visible through the first set of BOPP films (110). A luggage shell according to any one of claims 1 to 11 (720, 722, 734).

13. The second set of BOPP films (120) forms the inner surface of the laminate (100, 210), and the innermost BOPP film of the second set of BOPP films (120) is white. The color intensity of the laminate (100, 210) when viewed from its outermost surface is greater than that of an identically constructed laminate (100, 210) that does not include the white innermost BOPP film. A luggage shell (720, 722, 734) according to any one of claims 1 to 12.

14. A luggage shell (720, 722, 734) according to any one of claims 1 to 13, One or more handles (774) attached to at least one of the luggage shells (720, 722, 734), Multiple wheels (772) attached to at least one luggage shell (720, 722, 734), A luggage case equipped with [features / equipment].

15. To form a layup relating to the laminate (100, 210) according to any one of claims 1 to 13, In an isobaric press, the layup is laminated with uniform pressure, Forming the (100, 210) layups, which are stacked using a plug cavity mold, onto the luggage shell (720, 722, 734), A method for manufacturing luggage shells (720, 722, 734), including the above.

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