Composite lamina for forming luggage articles

Abstract

A travel bag outer shell (720, 722, 734) formed from a laminate (100, 210) is disclosed. The laminate (100, 210) comprises a first set of bopp films (110), at least one of the first set of bopp films (110) comprises a film having a core (202, 302) of a thermoplastic polymer and at least one outer layer (204) of a thermoplastic polymer, and both of these may be co-extruded. The laminate (100) comprises a second set of bopp films (120), each of the second set of bopp films comprises a co-extruded film having a core (202, 302) of a thermoplastic polymer and at least one outer layer (204) of a thermoplastic polymer. The laminate (100, 210) comprises at least one sheet of woven plastic material (130, 150, 400) disposed between the first set of bopp films (110) and the second set of bopp films (120). The laminate (100) comprises at least one matrix layer (140, 141, 142, 143) disposed on at least one side, such as the top or outward-facing side, of at least one of the sheets of woven plastic material (130, 150, 400).

Description

Technology Field

[0001] The present invention relates to a composite laminar for molding a travel bag. Background Technology

[0002] Hard-sided travel suitcase cases provide durability and support by constructing the exterior of the case using moldable and relatively rigid materials. One disadvantage of these materials is that they are difficult to manufacture and mold, and exhibit low tolerances for minute variations during the manufacturing and molding processes. These demanding characteristics of the material are particularly pronounced when producing deep-drawn products. Travel suitcase shells or case parts produced from such materials may need to be relatively thick and / or relatively heavy to achieve the desired strength. Not only the materials, but also the manufacturing and molding processes can be costly and time-consuming.

[0003] Literature that may be related to the present disclosure in that it includes various approaches to materials for travel bags includes US 8,052,913, US 11,135,756, and EP 3455063. WO 2022 / 263585 discloses a moldable and tear-resistant polymer composite. This composite comprises an outer woven polymer fabric layer disposed around an oriented polymer film core and bonded via an adhesive. This composite is moldable, such as for a travel bag. However, these approaches have room for improvement.

[0004] The embodiments disclosed in this document relate to a travel bag shell formed from a laminate having several sets of biaxially oriented polypropylene (BOPP) films, at least one sheet of woven plastic material (e.g., a self-reinforcing polypropylene sheet), and at least one matrix layer disposed on top of said at least one sheet of woven plastic material.

[0005] The present disclosure provides an improved plastic laminate material that is particularly thin, lightweight, strong, and impact-resistant. This material is versatile and suitable for deep drawing into articles such as travel bag shells. Travel bag shells made of this laminate are lightweight, thin, durable, and resistant to deformation, and possess excellent impact resistance and resilience during use and handling.

[0006] In one embodiment, a travel bag shell formed by a laminate is disclosed. The laminate comprises a first set of BOPP films, at least one of the first set of BOPP films comprises a film having a core of a thermoplastic polymer and at least one outer layer of a thermoplastic polymer, and the two may be co-extruded. The laminate comprises a second set of BOPP films, each of the second set of BOPP films comprises a co-extruded film having a core of a thermoplastic polymer and at least one outer layer of a thermoplastic polymer. The laminate comprises at least one sheet of woven plastic material 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 surface of at least one of the at least one sheet of woven plastic material, for example, a top surface or an outward-facing surface.

[0007] A BOPP film comprises at least one thermoplastic polymer layer that is stretched more in one direction than in the other, either the transverse direction (TD) or the mechanical direction (MD, e.g., longitudinal direction). Such a stretched film is referred to as a biaxially stretched polypropylene film and provides higher strength and melting point than an unstretched film of the same formulation.

[0008] At least one woven plastic material sheet may comprise a self-reinforcing polypropylene (SRPP) sheet, which is woven with an oriented (e.g., stretched) polypropylene tape to form a fabric having improved strength and heat resistance in the machine direction of the tape compared to the non-woven layer. Thus, the woven tape provides increased strength in both the machine direction and the transverse direction of the resulting woven plastic material sheet and the laminate containing it.

[0009] In some examples, the travel bag shell further comprises a third set of BOPP films disposed between a first set of BOPP films and a second set of BOPP films. In these examples, at least one woven plastic material sheet comprises a first woven plastic material sheet disposed between a first set of BOPP films and a third set of BOPP films, and a second woven plastic material sheet disposed between a second set of BOPP films and a third set of BOPP films.

[0010] In some examples, at least one matrix layer comprises a first matrix layer disposed on the upper surface or the outward-facing surface of the first woven plastic material sheet, a second matrix layer disposed on the lower surface or the inward-facing surface of the first woven plastic material sheet, and a third matrix layer disposed on the upper surface or the outward-facing surface of the second woven plastic material sheet.

[0011] At least one matrix layer strongly bonds the woven plastic material sheet to adjacent layers, for example, at least one woven plastic material sheet and the adjacent BOPP film. The woven plastic material sheet, such as SRPP material, has parts that are difficult to bond with other materials, such as polypropylene homopolymer or copolymer used in BOPP films.

[0012] In some examples, the travel bag shell comprises 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.

[0013] In some examples, the travel bag shell comprises 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 comprises a first matrix layer disposed on the upper surface of a first woven plastic material sheet, a second matrix layer disposed on the lower surface of the first woven plastic material sheet, and a third matrix layer disposed on the upper surface of a second woven plastic material sheet.

[0014] In some examples, the total thickness of the travel bag shell and laminate is 1.5 mm or less.

[0015] The laminates disclosed in this document are relatively thin yet still provide excellent strength, impact resistance, resilience, and aesthetic appearance.

[0016] In some examples, the first set of BOPP films has a thickness of 5% to 15% of the total thickness of the laminate inside the travel bag shell.

[0017] In some examples, the second set of BOPP films has a thickness of 12% to 18% of the total thickness of the laminate within the travel bag shell.

[0018] In some examples, the laminate comprises a third set of BOPP films disposed between a first set of BOPP films and a second set of BOPP films. In these examples, at least one woven plastic material sheet comprises a first woven plastic material sheet disposed between a first set of BOPP films and a third set of BOPP films, a second woven plastic material sheet disposed between a second set of BOPP films and a third set of BOPP films, a third woven plastic material sheet disposed between a first woven plastic material sheet and a second woven plastic material sheet, and a fourth woven plastic material sheet disposed between a third woven plastic material sheet and a second woven plastic material sheet. In these examples, at least one matrix layer comprises a first matrix layer disposed on the upper surface of a first woven plastic material sheet, a second matrix layer disposed on the upper surface of a second woven plastic material sheet, a third matrix layer disposed on the upper surface of a third woven plastic material sheet, and a fourth matrix layer disposed on the upper surface of a fourth woven plastic material sheet.

[0019] In some examples, the third set of BOPP films has a thickness of 35% to 45% of the total thickness of the travel bag shell laminate.

[0020] In some examples, the first set of BOPP films has a thickness of 5% to 15% of the total thickness of the laminate, the second set of BOPP films has a thickness of 12% to 18% of the total thickness of the laminate, and the third set of BOPP films has a thickness of 35% to 45% of the total thickness of the laminate.

[0021] In some examples, at least one sheet of woven plastic material has a thickness of less than 10% of the total thickness of the travel bag shell laminate.

[0022] The thickness of at least one sheet of woven plastic material allows the laminate of the travel bag shell to be relatively thin and light, yet strong, impact-resistant, and resilient.

[0023] In some examples, at least one matrix layer comprises a maleic anhydride-grafted polypropylene (MAPP) layer or a polypropylene film layer.

[0024] In some examples, at least one woven plastic material sheet includes at least one self-reinforcing polypropylene (SRPP) sheet.

[0025] In some examples, at least one woven plastic material sheet comprises a plurality of longitudinally stretched polypropylene tapes arranged in a selected weave pattern, said selected weave pattern may be visible through a first set of BOPP films.

[0026] In some examples, at least one woven plastic material sheet contains a coloring agent. In some examples, at least one matrix material contains a coloring agent.

[0027] In some examples, at least one matrix layer, at least one sheet of woven plastic material, one or more of a first set of BOPP films, or a second set of BOPP films, or any combination thereof, comprises a coloring agent, said coloring agent may be at least partially visible through the first set of BOPP films.

[0028] In some examples, a 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 when viewed from the outermost surface of the laminate is higher than that of a laminate of the same or similar composition that does not include the innermost BOPP film which is white.

[0029] By utilizing a substantially transparent or translucent BOPP film and a matrix layer between the outer surface of the laminate and the upper or outer surface of at least one woven plastic material sheet, the aesthetic appearance of the laminate is selectively controlled so that the weave of at least one woven plastic material sheet is visible. The coloring agent within at least one matrix layer is at least partially transparent or translucent so that the weave of at least one woven plastic material sheet can be visible with added color.

[0030] In some examples, one or more handles are attached to at least one suitcase shell, and multiple wheels are attached to at least one suitcase shell.

[0031] In one embodiment, a method for manufacturing a travel bag shell is disclosed. The method comprises the step of forming a layup according to any laminate disclosed herein. The method may comprise the step of laminating said layup under uniform pressure in an isostatic press. The method comprises the step of forming said laminated layup into a travel bag shell using a plug cavity mold.

[0032] The laminates disclosed in this document are formed under uniform pressure in a press to prevent air entrapment, delamination, and degradation of the physical properties (e.g., strength) of the resulting laminate and travel bag shell. Additionally, the laminates disclosed in this document provide a material that can be easily deep drawn within a mold to form a travel bag shell having an aesthetically excellent appearance.

[0033] By utilizing polypropylene-based materials in the film, the films within the laminate can be bonded to each other and possess complementary physical properties. This configuration provides the advantages disclosed above.

[0034] Features from any of the disclosed embodiments may be combined with one another without limitation. Additionally, other features and advantages of the present disclosure will become apparent to those skilled in the art by considering the following detailed description and the accompanying drawings. Brief explanation of the drawing

[0035] It is understood that these drawings illustrate only typical embodiments of the invention and are therefore not to be construed as limiting the scope of the invention, and that embodiments of the invention will be described and explained with further specificity and detail using the accompanying drawings. FIG. 1 is a cross-sectional view of a laminate for use in a travel bag shell, according to at least some embodiments. FIG. 2 is an isometric view of a partially broken BOPP film according to at least some embodiments. FIG. 3 is an isometric perspective view of a partially broken extrusion tape according to at least some embodiments. FIG. 4 is an isometric cross-sectional view of a woven plastic material sheet according to at least some embodiments. FIG. 5 is a schematic example of a double belt press according to at least some embodiments. FIG. 6a is an isometric perspective view of a molding device according to at least some embodiments. FIG. 6b is a perspective view of a sheet gripping rack according to one embodiment. FIG. 6c is a perspective view of a gripping bar of a gripping rack according to one embodiment. FIG. 7a is a front isometric perspective view of a travel bag shell according to at least some embodiments. FIG. 7b is a rear isometric perspective view of a travel bag shell according to at least some embodiments. FIG. 7c is an isometric view of a hard-side travel bag case according to at least one embodiment. FIG. 8 is a diagram of a method for manufacturing a travel bag shell according to at least some embodiments. Figures 9a and 9b are graphs of the stiffness test results of exemplary travel bag shells in the machine direction and transverse direction, respectively. Figures 10a and 10b are graphs of the elastic test results of an exemplary travel bag shell in the machine direction and transverse direction, respectively. Figures 11a and 11b are graphs of the results of the bending modulus test in the machine direction and transverse direction, respectively. Figure 12 is a graph of the T-peeling test results. Figure 13 is a graph of the additional T-peeling test results. Figure 14 is a temperature profile graph for Example 1. Specific details for implementing the invention

[0036] The embodiments disclosed herein relate to a travel bag shell formed from a laminate having several sets of BOPP films and at least one sheet of woven plastic material. The present disclosure provides an improved laminate material for a travel bag shell and an improved travel bag shell composed of said material. In particular, the present disclosure provides a laminate that is lightweight, elastic (e.g., indentation resistant), impact resistant, versatile, and suitable for deep drawing. Generally, the material consists of a set of plastic films laminated together. A travel bag shell composed of said material is lightweight, thin, durable, resistant to deformation, and elastic. The fact that the material is suitable for a deep drawing process helps to produce a travel bag shell that is substantially wrinkle-free, including in the corner areas, and helps to produce a high-quality surface finish, either separately or in combination. As used in this document, the term "constructed of" may mean "comprising."

[0037] The present disclosure provides a method for manufacturing a laminate that is strong, elastic, and has a beautiful appearance. The present disclosure also provides a method for manufacturing a travel bag shell from an improved material that is relatively easy, fast, and inexpensive. This material can be heated, subjected to tensile force, and deep drawn to produce a travel bag shell.

[0038] FIG. 1 is a cross-sectional view of a laminate (100) for use in a travel bag shell according to at least some embodiments. The laminate (100) comprises a set of polypropylene film layers. In some embodiments, the laminate (100) comprises a first set of BOPP films (110), a second set of BOPP films (120), at least one woven plastic material sheet (e.g., SRPP, etc.) (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 (e.g., a top or outward-facing surface or face) of at least one of the woven plastic material sheets (130 or 150). The laminate has an outer surface (102) facing outward (shown at the top in FIG. 1) toward an observer or the outer surface of the travel bag shell. The laminate (100) includes an inner surface (104) that faces away from the observer or forms the inner surface of the travel bag shell. At least one sheet of woven plastic material (130 and 150) is located inside the laminate (100), such as between the outer surface (102) and the inner surface (104).

[0039] As illustrated in FIG. 1, in some embodiments, the laminate (100) comprises a third set of BOPP films (180) disposed between first and second sets of BOPP films (110 and 120). In these embodiments, the laminate (100) comprises both a first woven plastic material sheet (130) disposed between the first set of BOPP films (110) and the third set of BOPP films (180), and a second woven plastic material sheet (150) disposed between the second set of BOPP films (120) and the third set of BOPP films (180). Each woven plastic material sheet comprises at least one corresponding matrix layer (140 or 142) on at least one side thereof (e.g., the top side). Additionally, the woven plastic material sheets (130 and 150) may each independently comprise a matrix layer (141 or 143) on their opposite sides.

[0040] As described in detail below, each BOPP film set (110, 120, or 180) comprises at least one oriented thermoplastic film layer(s), and in the embodiments, one or more layers or all layers of each BOPP film set (110, 120, or 180) are oriented thermoplastic film(s). At least one woven plastic material sheet (130 and 150) may comprise longitudinally stretched polypropylene tapes woven together in at least two directions (e.g., warp and weft) to form a polymer fabric. At least one matrix layer (140-143) may comprise a polymer film (e.g., polypropylene) configured to be bonded to at least one woven plastic material sheet and BOPP film material between which it is located.

[0041] Individual film layers of the laminate (100) can be combined with each other to form the laminate (100). These film layers may be formed separately before or simultaneously with combining the film layers to form the laminate (100) and combined to form a layup (e.g., a sheet of laminated film, sheet and layer). Although the drawing is 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 greater than 0.5 mm. The laminate (100) may have a weight of at least about 0.7 g / m², for example, about 0.7 g / m² to about 3.0 g / m², about 0.7 g / m² to about 1.3 g / m², about 1.0 g / m² to about 1.2 g / m², about 1.2 g / m² to about 1.8 g / m², about 1.8 g / m² to about 2.5 g / m², less than about 2.5 g / m², less than about 1.5 g / m², or less than about 1.2 g / m². The relatively thin and light laminate (100) provides excellent rigidity, resistance to indentation, and deep drawing ability during molding.

[0043] The individual film layers of the laminate (100) have similar or different properties and characteristics to provide the selected stiffness, aesthetic appearance, weight, elasticity (indentation resistance), versatility, and deep drawing ability to the final laminate (100). The various layers of the laminate (100) are discussed separately 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, fewer than 10 BOPP films, or fewer 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, 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 of 5% to 15% of the total thickness of the laminate (100). The thicknesses of each BOPP film (112, 114, or 118) may be the same or different from each other. The BOPP films (112, 114, or 118) may differ from each other in other characteristics such as material composition, surface treatment, etc.

[0045] At least some of the BOPP films (112, 114, or 118) (e.g., each) may comprise a core layer of a biaxially oriented thermoplastic polymer and at least one outer layer of a thermoplastic polymer. FIG. 2 is an isometric perspective view of a partially broken BOPP film (200) according to at least some embodiments. The BOPP film (200) may be used independently as the BOPP film (112, 114, or 118) ( FIG. 1) within a 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 embodiment, the BOPP film (200) comprises at least one core layer (202) and at least one outer layer (204). The at least one outer layer (204) may be located on the top surface (203), bottom surface (205), or both sides of the core (202). In some embodiments (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, the “biaxially oriented” film refers to a film stretched in two different directions and includes, as a non-limiting example, that it is stretched in the transverse direction and the machine direction (e.g., longitudinal direction). In the embodiments, the biaxially oriented film may be stretched up to 12 times in the transverse direction (e.g., 6 to 10 times or 9 times) and up to 10 times in the machine direction (e.g., 3 to 8 times or 4 to 6 times) compared to the original dimensions of the unstretched film.

[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 composed of BOPP.

[0048] At least one outer layer (204) is composed of an oriented or unoriented heat-fusible material. In some embodiments, at least one outer layer (204) is composed substantially of polypropylene (PP). In some embodiments, at least one outer layer (204) is composed of a copolymer of PP and polyethylene (PE). Polyethylene may account for up to about 5% of the copolymer. In some embodiments, the outer layer (204) is composed of a terpolymer of PP, PE, and polybutene (PB). Polyethylene and polybutene together may account for 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 and may include, for example, at least 10% recycled PP (e.g., at least 75% or at least 90%).

[0049] In some embodiments, the core (202) and at least one outer layer (204) comprise compatible or complementary polymers so that the core (202) and at least one outer layer (204) can be co-extruded. For example, the core (202) and at least one outer layer (204) may be composed of thermoplastic polymers. In some embodiments, the core (202) is composed of an oriented polypropylene homopolymer (OPP) and at least one outer layer (204) is composed of a copolymer of PP and PE. In some embodiments, the core (202) is composed of an oriented polypropylene homopolymer and at least one outer layer (204) is composed of a terpolymer of PP, PE, and polybutene. In some embodiments, 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 in melting point between the core (202) and the 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. If the difference in melting point between the core (202) and the outer layer (204) is greater (e.g., 60°C instead of 5°C), it may help to produce a laminate having improved mechanical and / or physical properties (e.g., an integral structure of film layers bonded together). Without being limited to any mechanism or mode of operation, a larger melting point difference may enable lamination at a temperature where at least one outer layer (204) melts but the core (202) does not. When the processing temperature reaches the melting point of the core (202), the core (202) may begin to soften and the molecules of the core (202) may lose their orientation, which consequently may degrade the physical and mechanical properties of the resulting laminate (210) compared to a laminate (210) in which the core (202) has not melted or softened. A laminate formed with the core softened may still be suitable for use and is included in the embodiments disclosed herein.

[0051] If the difference in melting points between the core (202) and at least one outer layer (204) is at least about 10°C or more, it may be easier to laminate a set of films (200) together. When the processing temperature is sufficient to melt or partially melt at least one outer layer (204) but not enough to melt the core (202), the layers of BOPP films (200) may slide up against each other or adjacent BOPP films (200) may slide up against each other during the process of forming the laminate. The mechanical properties of the laminate are best maintained by not substantially melting the core (202) during the manufacturing of the laminate sheet, but in an alternative embodiment, even if the core (202) softens or partially melts during the manufacturing of the laminate, the mechanical properties may be reduced but may still be suitable for further use. Additionally, the difference in melting points can make the molding process of the laminate easier because the laminate becomes processable due to the melting or partial melting of at least one outer layer (204) and the melting, partial melting, or softening of the core (202).

[0052] At least one outer layer (204) defines an outer surface (206) and an inner surface (208) that are bonded adjacent to the BOPP film (200). The outer surface (206) may be corona treated, which may help provide 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 be corona treated on the outer surface (206) to better adhere to the immediately adjacent film. For example, the outer surface (206) of the outermost film(s) in the first set of films (110) may be corona treated.

[0053] A core (202) and at least one outer layer (204) can be co-extruded to form a BOPP film (200). In contrast to woven fabrics, which form plastic fabrics by weaving threads or tapes in two directions (warp and weft), the BOPP film (200) is produced by extruding multiple layers simultaneously. For example, at least one outer layer (204) and the core (202) are co-extruded to produce a BOPP film (200).

[0054] A specific BOPP film (200) suitable for use in the first set of BOPP films (110) may include a KXE heat-fusible BOPP film having a PP outer layer and a BOPP core (product of TATRAFAN, Slovakia, sro), an ONXE BOPP film having a PP outer layer and a BOPP core (product of TERICHEM, Slovakia, as), a KXHSS heat-fusible BOPP film having a polypropylene outer layer and a BOPP core (product of TATRAFAN, Slovakia, sro), etc.

[0055] The BOPP film (200) may have a thickness of about 10 μm to about 100 μm, about 10 μm to about 30 μm, about 30 μm to about 50 μm, about 40 μm, about 20 μm, or less than about 40 μm. The BOPP film (200) may have a unit weight of about 0.015 g / m² to about 0.04 g / m², for example, about 0.015 g / m² to about 0.020 g / m², about 0.020 g / m² to about 0.030 g / m², about 0.030 g / m² to about 0.040 g / m², about 0.034 g / m² to about 0.037 g / m², or less than 0.040 g / m². 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 embodiments, the BOPP film (200) may be a color other than white. In some embodiments, the color, whether white or another color, is applied only to the core layer.

[0056] In forming the laminate (100), various versions of the BOPP film (200) may be utilized, such as using multiple layers with the same characteristics, multiple layers with different characteristics, or all of these. Referring again to FIG. 1, each BOPP film (112, 114, or 118) of the first set of BOPP films (110) may be independently similar or identical to one or more aspects, such as material composition, thickness, etc. For example, the BOPP films (112 and 114) may be identical to one another, and the BOPP film (118) may differ from the BOPP films (112 and 114) in one or more aspects. Likewise, the BOPP films (114 and 118) may be identical to one another, and the BOPP film (112) may differ from the BOPP films (114 and 118) in one or more aspects. In some embodiments, the first set of BOPP films (110) may comprise five BOPP films, with two additional BOPP films positioned between BOPP films (114) and BOPP films (118). In embodiments throughout this document, the BOPP films (114, 118) and the additional BOPP films may comprise KXE (e.g., KXE-S1, KXE-40, or other KXE films) heat-sealable BOPP films, and BOPP film (112) may comprise ONXE BOPP films. In these embodiments, fewer or more BOPP films may be utilized to provide a selected thickness or weight in the laminate (100). Many combinations of the number of BOPP films, material types, thickness, weight, etc., may be utilized 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, matte, or satin finish.

[0057] A first set of BOPP films (110) can form an outer surface (102) on a laminate (100). For example, the BOPP films (112) can form the outermost outer surface (102) of the laminate (100). Thus, in some embodiments, the first set of BOPP films (110) may comprise a sufficient number of individual BOPP films to provide a selected surface finish, such as a smooth finish, on the outer surface of the laminate despite the underlying layers having thickness variations. For example, the weave pattern of a woven plastic material sheet, such as an SRPP sheet, may exhibit a texture on the surface of the laminate via print-through, provided that the first set of BOPP films does not provide enough polymer material between the woven plastic material and the surface to fill the thickness variation of the underlying weave pattern during the lamination process. In some embodiments, an appropriate amount of the first set of BOPP films to provide a smooth surface of the laminate may comprise three to five BOPP films.

[0058] The second set of BOPP films (120) may be similar or identical to the first set of BOPP films (110) and BOPP films (200) in one or more aspects. For example, the second set of BOPP films (120) may each comprise a biaxially oriented thermoplastic polymer core and at least one thermoplastic polymer outer layer as disclosed above in relation to the first set of BOPP films (110). In some embodiments, at least some of the second plurality of BOPP films (120) may not comprise at least one outer layer. The second set of BOPP films (120) may have 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, 1 to 10 BOPP films, 2 to 10 BOPP films, 3 to 6 BOPP films, 5 to 10 BOPP films, fewer than 10 BOPP films, or fewer than 5 BOPP films. For example, the second set of BOPP films (120) may include BOPP films (122, 124, or 128).

[0060] One or more BOPP films (122, 124, or 128) may be similar or identical to one or more others independently. For example, BOPP films (122 and 124) may be identical to one another, and BOPP film (128) may be different from BOPP films (122 and 124) in one or more aspects. Likewise, BOPP films (124 and 128) may be identical to one another, and BOPP film (122) may be different from BOPP films (124 and 128) in one or more aspects. In some embodiments, a second set of BOPP films (120) may include four BOPP films, and an additional BOPP film is positioned between BOPP film (124) and BOPP film (128). In these embodiments, the BOPP films (122 and 124) may comprise KXE heat-fusible BOPP films, and the additional BOPP film and BOPP film (128) may comprise KXHSS heat-fusible BOPP films. In some embodiments, the second set of BOPP films (120) comprises not only the BOPP films (122 and 124) composed of KXE heat-fusible BOPP films, but also a BOPP film (128) composed of KXHSS heat-fusible BOPP films and at least one additional BOPP film (placed between the BOPP films (124 and 128)). Many combinations of the number, material type, thickness, weight, etc. of the BOPP films may be utilized to form the second set of BOPP films (120).

[0061] In some embodiments, the second set of BOPP films (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] A second set of BOPP films (120) may form the inner surface (104) of the laminate (100). For example, BOPP films (128) may form the innermost layer and the inner surface (104) of the laminate (100). In some embodiments, the innermost BOPP film(s) of the second set of BOPP films (120) may contain a coloring agent. For example, one or more innermost BOPP film(s) (e.g., 122, 124, or 128) may be colored white. In these embodiments, the color of the laminate (100) viewed from the outermost surface exhibits greater color intensity or brightness than in embodiments without the white innermost BOPP film.

[0063] The laminate (100) comprises at least one woven plastic material sheet, such as an SRPP sheet, disposed 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 comprise one sheet of woven plastic material, two sheets of woven plastic material, three sheets of woven plastic material, four sheets of woven plastic material, at least five sheets of woven plastic material, or fewer than five sheets of woven plastic material. For example, the at least one woven plastic material sheet may comprise 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 comprises thermoplastic tapes 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 comprises one or more longitudinally stretched thermoplastic tapes woven into a sheet. FIG. 3 is an isometric perspective view of a partially broken extruded tape (300) according to at least some embodiments. As illustrated, the tape (300) may comprise a core layer (302) and at least one outer layer (304). In some embodiments, the tape (300) may comprise only the core layer (302). In some embodiments, the tape (300) may comprise at least one outer layer (304) on only 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 combined (e.g., bonded) by one or more of co-extrusion, heating, etc. to form the tape (300). For example, the stretched polymer forming the core layer (302) can be co-extruded with the stretched or unstretched polymer forming at least one outer layer (304) on both sides of the core layer (302) to form a tape (300).

[0065] Thermoplastic polymers suitable for use in the core layer (302) include one or more of polypropylene, polyethylene, polyamide, polyester, polyvinyl alcohol, polycarbonate, polylactic acid, polybutene, acrylonitrile butadiene styrene (ABS), etc. For example, the core (302) may include a polypropylene homopolymer stretched to a selected amount. The core (302) may include a copolymer such as a PP / PE copolymer in which PE is a small component of the copolymer (e.g., 5 wt% or less). Furthermore, the core (302) may include a terpolymer, a quarterpolymer, etc. Polypropylene may be a major component in the polymer forming the core (302).

[0066] The core (302) can be stretched in the longitudinal direction (e.g., machine direction) and, in one embodiment, can be stretched 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 in the longitudinal direction 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 greater strength and resilience than the same unstretched polymer film.

[0067] At least one outer layer (304) is composed of an oriented or unoriented thermoplastic polymer, such as any thermoplastic polymer disclosed herein. In some embodiments, the outer layer (304) is composed of a homopolymer consisting substantially only of PP. In some embodiments, the outer layer (304) comprises a copolymer of PP and PE. PE may account for up to about 5% of the copolymer. In some embodiments, the outer layer (304) is composed of a terpolymer. The compositional match between the material in the core (302) and at least one outer layer (304) provides a strong bond between each layer in the tape (300).

[0068] The core (302) and at least one outer layer (304) of the tape (300) comprise compatible or complementary polymers so that the core (302) and the outer layer (304) can be co-extruded. For example, the core (302) and the outer layer (304) may be composed of the same thermoplastic polymer. The core (302) and the outer layer (304) may differ in the degree of orientation (e.g., stretching) of the polymer film in each layer. In some embodiments, 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 embodiments, 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. Any of the materials of the core (302) or at least one outer layer (304) disclosed in this document may be formed from at least partially recycled material and may include, 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, for example, from 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, for example, from about 130°C or lower. The difference between the melting point of the core (302) and the melting point of 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. If the difference in melting points between the core (302) and the outer layer (304) is greater (e.g., 60°C instead of 5°C), it may help to produce a laminate with improved mechanical and / or physical properties (e.g., an integral structure of film layers bonded together). Without being limited to any mechanism or mode of operation, a greater difference in melting points may enable lamination at a temperature where the outer layer (304) melts but the core (302) does not. When the processing temperature reaches 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 consequently may degrade the physical and mechanical properties of the resulting tape (300) compared to a tape (300) in which the core (302) has not melted or softened.

[0070] In some embodiments, the tape (300) may not include at least one outer layer (304). In these embodiments, a core (304) having a higher melting point than the absent at least one outer layer (302) may not easily bond to the layers surrounding the tape (300) or to the sheet formed therefrom (e.g., woven plastic material 400) due to a mismatch in melting temperatures between them. Thus, a tape (300) without at least one outer layer (304) may be used, but a tape (300) having at least one outer layer (304) provides a stronger bond to the BOPP film and matrix layer disclosed in this document.

[0071] The tape (300) may be transparent, translucent, or opaque. The tape (300) may include a coloring agent 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 provide color to the tape (300) and at least one woven plastic material sheet (130 or 150) resulting therefrom (Fig. 1). The coloring agent may be provided to the tape (300) by pigment(s) added to the polymer(s) therein, such as a white pigment in a polypropylene homopolymer. The coloring agent may control the transparency, translucency, or opacity of the tape (300). Accordingly, at least one woven plastic material sheet containing the colored tape (300) will contain the coloring agent. The colored tape (300) may be visible through the entire laminate from the outer surface of the laminate.

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

[0073] Two or more tapes (300) are woven together to form a woven plastic material or fabric (e.g., an SRPP layer). FIG. 4 is an isometric cross-sectional view of a woven plastic material sheet (400) according to at least some embodiments. As illustrated, the woven plastic material sheet (400) is formed from polymer tapes (402 and 404) woven in a selected weaving pattern. The polymer tapes may be similar or identical to the tape (300) in one or more aspects. The woven plastic material sheet (400) may be in the form of an SRPP sheet.

[0074] In some embodiments, one or more of the warp or weft threads within the woven plastic material sheet may be formed into a tape having a cumulative transverse width of at least 110%, for example, at least 120%, at least 140%, at least 150%, 200% or less, or 160% or less of the corresponding dimension (e.g., length or width) of the woven plastic material sheet. In some embodiments, 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, or less than 5 mm. The overlapping tapes may increase the visibility of the woven pattern within the laminate (100) and may reduce the occurrence of gaps or empty spaces between the tapes.

[0075] The selected weave pattern may include twill (e.g., 2 x 2), plain weave, satin weave, dug weave, slash weave, slash twill weave, 3 x 1 weave, or variations thereof. In some embodiments, the weave pattern may provide a three-dimensional weave pattern designed to provide a selected texture or the appearance of a texture to the laminate (100). In some embodiments, a composite weave pattern, such as a weave pattern for manufacturing a multilayer woven fabric, also referred to as a three-dimensional weave pattern, may be utilized. In a composite weave pattern, multiple layers of warp and / or weft yarn may be used. In some embodiments, the three-dimensional weave pattern may include three or more yarn systems corresponding to multiple layers of warp and weft yarn. In other embodiments, one or more tapes may be twisted together to form either a weft or a warp. Such twisting may provide three-dimensional properties to the resulting woven plastic material. A three-dimensional pattern can be formed within a woven plastic material by utilizing a tape twisted on one or more of the warp or weft as a selected pattern.

[0076] At least one sheet of woven plastic material may contain one or more coloring agents. For example, one or both of the (warp and weft) tapes (404 and 402) may contain a selected coloring agent. In some embodiments, the warp and weft of the woven plastic material may contain different coloring agents. In some embodiments, the weft may contain different coloring agents throughout the woven plastic material sheet, and, for example, coloring agents may be alternately or randomly placed at every second tape, every third tape, every fourth tape, every fifth tape of the weft. The warp may have different coloring agents throughout the woven plastic material sheet, such as at least five consecutive tapes of the warp or weft. One or both of the warp or weft may contain tape blocks of the same color, such as at least five consecutive tapes of the warp or weft. Accordingly, at least one woven plastic material sheet (400) can provide at least one part of a selected aesthetic appearance on the surface of the laminate (100), particularly when closest to the outer surface of the laminate (100).

[0077] In some embodiments, one or more of the warp or weft threads may contain fibers such as aramid fibers, carbon fibers, glass fibers, etc. These fibers may be located at every second, every third, every fourth, and every fifth tape of the warp or weft threads within the woven plastic material sheet. In these embodiments, at least some of the polypropylene tapes within the warp or weft threads may be replaced with polymer tapes or fibers (e.g., high-performance polymer fibers or tapes) made of or containing one or more of carbon, aramid, or glass fibers. These tapes may include Endumax® (ultra-high molecular weight polyethylene) hybrid or composite tapes (products of Teijin Aramid). In the embodiments, the polymer fibers may be in an internal layer form present within the woven fabric sheet. In these embodiments, one of the four tapes may be a high-performance polymer fiber or tape, and in additional embodiments, the warp tapes may include high-performance polymer fibers or tapes. Alternatively, the high-performance polymer fibers or tapes may be included in the woven fabric sheet or form the entire sheet to form additional sheets or sheets within the laminated layup. In these embodiments, the preferred tape may include a highly stretched polymer tape containing fibers to aid in recycling after the end of its life.

[0078] Tapes (402 and 404) may be similar or identical to tape (300) in one or more aspects. For example, tapes (402 and 404) may be co-extruded such that the core layer has a higher melting point than at least one outer layer by stretching the core layer in the longitudinal direction (e.g., machine direction) while at least one outer layer is not stretched.

[0079] Tapes (402 and 404) are woven in two directions to form a woven plastic fabric. As illustrated, tape (402) is illustrated as a weft (e.g., a tape extending transversely along the longitudinal axis of the woven plastic material sheet (400)), and tape (404) is illustrated 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 tape (402 and 404) extending perpendicularly to each other in the warp and weft, the resulting at least one woven plastic material sheet (400) possesses greater strength and resilience than a woven fabric without a stretched core within the tape.

[0080] Suitable woven plastic material sheets (400) include Torodon™ SRPP fabric (manufactured by Don & Low of Popper, Scotland, UK), Tegris® fabric (manufactured by Milliken Textiles of Ghent, Belgium), etc.

[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 embodiments, at least one woven plastic material sheet (400) has a thickness of less than about 10% of the total thickness of the laminate (100) (Fig. 1) or the layup to form it. For example, at least one woven plastic material sheet (400) may individually have a thickness of about 1% to 10% of the laminate or the layup to form it. When at least two sheets are used in the laminate, the woven plastic materials (130 or 150) may be the same or different from each other. For example, the weaving method used in one woven plastic material sheet may differ from the weaving method used in another plastic material sheet. In another embodiment, the degree of elongation of each core layer (302) within one woven plastic material sheet may differ from that of another plastic material sheet. These differences in the woven plastic material sheets (130 and 150) may result in improved strength and resilience characteristics.

[0082] A matrix layer can be utilized to provide a strong bond between at least one woven plastic material sheet (130 or 150) and an adjacent BOPP film and to prevent interlayer separation.

[0083] In some embodiments, at least one woven plastic material may include one or more polymer films placed on the woven fabric of the tape (404 and 402) (e.g., on it).

[0084] Referring again to FIG. 1, the laminate (100) comprises at least one matrix layer (140 or 142) disposed on one side of each of at least one woven plastic material sheet (130 or 150), for example, on the top or outward-facing side. In some embodiments, the at least one matrix layer (140 or 142) is present only on the top or outward-facing surface side of the at least one woven plastic material sheet (130 or 150). The laminate may further comprise at least one matrix layer (141 or 143) disposed on one or more opposite sides of the at least one woven plastic material sheet (130 or 140), for example, on the bottom or inward-facing surface side. For example, at least one matrix layer may include a (first) matrix layer (140) disposed on the top surface of the first woven plastic material sheet (130), a (second) matrix layer (141) disposed on the bottom surface of the first woven plastic material sheet (130), and a (third) matrix layer (142) disposed on the top surface of the second woven plastic material sheet (150). In some embodiments, a (fourth) matrix layer (143) is disposed on the bottom surface of the second SRPP layer (150).

[0085] At least one matrix layer is formulated to provide additional matrix material and to improve adhesion between the BOPP film and the woven plastic material. At least one matrix layer is formulated to be bonded or attached to at least one woven plastic material sheet (130 or 150) and 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, and in some embodiments, may be more than a single film layer. At least one matrix layer (140-143) may comprise an adhesive or material configured to be bonded to the films or layers in contact with it. For example, at least one matrix layer (140-143) may comprise a polypropylene layer, a maleic anhydride grafted polypropylene (MAPP) layer or other grafted polypropylene layer, or a polypropylene / polyethylene copolymer layer. In some embodiments, at least one matrix layer may be formulated to melt completely, partially, or not melt at all in response to heat applied, such as during lamination. One or more portions of at least one matrix layer may be configured to melt at a melting temperature in the same range as the melting temperature of the outer layer of the woven plastic material (130) and the outer layer of the BOPP film (e.g., the outer layer (in the case of partial melting), or the entire film (in the case of complete melting). 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 fabric). Suitable MAPP materials may include Rayotec MAPP 020 NT (manufactured by AMCOR, Zurich, Switzerland), Lamiten® film (manufactured by Chemosvit Folie, Czech Republic), etc.A polypropylene film layer suitable for use as at least one matrix layer may include a blown PP film or a cast PP film, such as a polypropylene film from NITTO ADVANCED FILM, Gronow, Germany. The at least one matrix film may include one or more layers inside. For example, the MAPP film may include up to five layers of MAPP material inside.

[0086] Any at least one matrix layer (140-143) may contain a coloring agent within. For example, at least one matrix layer (140) may contain a coloring agent that is substantially transparent or translucent within. In these embodiments, at least one matrix layer(s) may modify the aesthetic appearance or color of the laminate, such as enhancing the colored appearance of at least one woven plastic material. In some embodiments, at least one matrix layer (140) may contain a coloring agent that is substantially opaque within. In these embodiments, at least one matrix layer (140) may include an area without coloring agent, such as a cut-out that allows at least one woven plastic material underneath to be visible. The cut-out may provide a selected pattern (e.g., checkerboard), design, logo, text, etc., to the appearance of the laminate (100) and the travel bag shell formed therefrom.

[0087] Each of at least one matrix layer (140-143) may have a thickness of at least about 10 μm, 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 embodiments, 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 to form it.

[0088] Referring again to FIG. 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 this embodiment, 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] The third set of BOPP films (180) may be similar or identical to the first set of BOPP films (110) and BOPP films (200) in one or more aspects. For example, the third set of BOPP films (180) may include a thermoplastic polymer core and at least one thermoplastic polymer outer layer, each oriented biaxially as disclosed above in relation to the first set of BOPP films (110) and BOPP films (200). In some embodiments, at least some of the third set of BOPP films (180) may not include at least one outer layer. The third set of BOPP films (180) may have a different number of film layers, thickness, material composition, etc., than one or more of the first set of BOPP films (110) or 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, fewer than 20 BOPP films, fewer 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, or 188).

[0091] One or more BOPP films (182, 184, or 188) may be similar or identical to one or more others independently. For example, BOPP films (182 and 184) may be identical to one another, and BOPP film (188) may be different from BOPP films (182 and 184) in one or more aspects. Likewise, BOPP films (184 and 188) may be identical to one another, and BOPP film (182) may be different from BOPP films (184 and 188) in one or more aspects. In some embodiments, a third set of BOPP films (180) may include a total of seven BOPP films, with four additional BOPP films located between BOPP film (184) and BOPP film (188). In some embodiments, the third set of BOPP films (180) may include a total of 9 BOPP films, with 6 additional BOPP films located between BOPP film (184) and BOPP film (188). In some embodiments, the third set of BOPP films (180) may include a total of 11 BOPP films, with 8 additional BOPP films located between BOPP film (184) and BOPP film (188). In some embodiments, the third set of BOPP films (180) may include a total of 13 BOPP films, with 10 additional BOPP films located between BOPP film (184) and BOPP film (188). In some embodiments, the third set of BOPP films (180) may comprise a total of 14 BOPP films, with 11 additional BOPP films positioned between BOPP films (184) and BOPP films (188). In these embodiments, BOPP films (182-188) may comprise KXE heat-sealable BOPP films, and the additional BOPP films and BOPP film (188) may comprise KXE heat-sealable BOPP films.Any combination of the number, material type, thickness, weight, etc. of the BOPP films can be used to form the third set of BOPP films (180).

[0092] In some embodiments, the third set of BOPP films (180) may have a thickness of about 25% to about 55%, 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 include more or fewer layers than disclosed in FIG. 1. For example, more or fewer BOPP films, woven plastic material sheets, or matrix layers may be utilized than illustrated in FIG. 1. Although not illustrated in FIG. 1, in some embodiments, the laminate (100) may include 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 disposed within the laminate as an intermediate layer. More or fewer woven plastic material sheets may be utilized than illustrated in FIG. 1.

[0094] In some embodiments, the laminate may include two or more sheets of woven plastic material in combination with a first set of BOPP films (110) and a second set of BOPP films (120), and a third set of BOPP films (180) is placed between the first set of BOPP films (110) and the second set of BOPP films (120). In these embodiments, at least one woven plastic material sheet may include a first woven plastic material sheet (130) disposed between a first set of BOPP films (110) and a third set of BOPP films (180), a second woven plastic material sheet (150) disposed between a second set of BOPP films (120) and a third set of BOPP films (180), a third woven plastic material sheet (130) disposed between the first woven plastic material sheet (130) and the second woven plastic material sheet (150) (e.g., adjacent to the first woven plastic material sheet (130)), and a fourth woven plastic material sheet (150) disposed between the third woven plastic material sheet (130) and the second woven plastic material sheet (150) (e.g., adjacent to the second woven plastic material sheet (130)). In these embodiments, at least one matrix layer may include a (first) matrix layer (140) disposed on the top surface of a first woven plastic material sheet (130), a (second) matrix layer (142) disposed on the top surface of a second woven plastic material sheet, a (third) matrix layer disposed on the top surface of a third woven plastic material sheet (130), and a (fourth) matrix layer disposed on the top surface of a fourth woven plastic material sheet (150). In some embodiments, only the first and fourth woven plastic material sheets (130 and 150) may each include a matrix layer on their respective top surfaces, etc. In some embodiments, the second and third woven plastic material sheets (130 and 150) may include a matrix layer on their bottom surfaces.In some embodiments, all woven plastic material sheets (130 and 150) may each include a matrix layer on one or more of their top or bottom surfaces.

[0095] In some embodiments, the laminate (100) may include at least one intermediate layer disposed 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 non-woven material containing aramid, carbon, or glass fibers. A suitable intermediate layer may include Endumax® (ultra-high molecular weight polyethylene) hybrid or composite material (product of Teijin Aramid).

[0096] The layup or laminate (100) used to form the laminate (100) may have selected dimensions, for example, one or more of the width (e.g., transverse direction) or length (e.g., machine direction) may be at least 30 cm, e.g. 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 of the foregoing.

[0097] In some embodiments, individual layers (e.g., sheets, films, layers) may be oriented in the same direction so that the machine direction of each layer is aligned in a single direction. In these embodiments, there may be no individual layers oriented at an angle orthogonal to any other layer of the laminate with respect to the machine direction of the individual layers. This configuration limits or reduces the stretching of the individual layers in the transverse direction of the individual layers. In other embodiments, individual layers (e.g., sheets, films, layers) may be oriented at a certain angle with respect to an adjacent layer (top or bottom).

[0098] In some embodiments, a fabric or cloth layer may be placed on the inner surface (104) of the laminate (100) for the travel bag shell molding process, and may be used, for example, as a lining for the finished travel bag shell. The fabric or cloth layer may be knitted or made of a composite material having at least some degree of elasticity. In these embodiments, the additional layer may be co-extruded together with other layers during the molding process to form the laminate (100), or may be bonded to the inner surface (104) after lamination. The latter example may prevent lamination defects introduced by the fabric layer.

[0099] In some embodiments, starting from the outermost layer, the laminate (100) may comprise a first set of BOPP films starting with one ONXE BOPP film and followed by four KXE BOPP films. A first matrix layer (e.g., PP or MAPP film) placed over at least one first woven plastic material sheet (e.g., Torodon™ fabric) may be located beneath the first set of BOPP films. A second matrix layer (e.g., PP or MAPP film) may be placed beneath at least one first woven plastic material sheet. A second set of BOPP films located beneath the second matrix layer may comprise eleven BOPP films (e.g., KXE films), and a third matrix layer (e.g., PP or MAPP film) may be placed beneath the second set of BOPP films. At least one second woven plastic material sheet (e.g., Torodon™ fabric) may be placed beneath the third matrix layer. A third set of BOPP films may be placed under at least one second woven plastic material sheet, and the third set of BOPP films comprises 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 embodiment, the third set of BOPP films may comprise three KXE BOPP films without the KXHSS BOPP film. In this embodiment, the laminate (100) may comprise a bottom matrix layer, such as a PP or MAPP matrix layer, located beneath the third set of BOPP films. This bottom matrix layer helps to bond additional layers (e.g., a lining) to the laminate (100). Although not illustrated, the bottom matrix layer may be present in any laminate disclosed herein.

[0101] It should also be recognized that the laminate (100) illustrated in FIG. 1 may be a layup composed of the same layers described in relation to FIG. 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 in a laminating machine such as an isobaric press or an isothermal press. The pressure application device may include opposing oil cushions spaced apart by a gap. As used herein, “bar” generally refers to surface pressure generated by the press, though not exclusively. As used herein, “kN / m” generally refers to linear pressure generated by the press, though not exclusively. In the embodiments disclosed herein, the isobaric press has been proven to be particularly effective in significantly reducing or eliminating air bubble ingress typically present in samples made using an isobaric press.

[0103] FIG. 5 is a schematic illustration 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 can be pressed, heated, and combined to form a laminate. The double belt press may include an isostatic press or an isothermal press.

[0104] The lower press assembly (510) includes a lower press module (530) comprising a lower belt (511) and a lower press body (531) having a set of thermally connected thermal elements (532, 534 and 536). The lower press module (530) may be adjustable to deflect the lower belt (511) toward the upper press assembly (520) or in the opposite direction.

[0105] The thermal elements (532, 534 and 536) enable a combination of heating and / or cooling along the longitudinal length of the lower pressurized module (530) to form a laminate thereon.

[0106] The upper press assembly (520) includes an upper press module (540) comprising an upper belt (521) and an upper press 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 pressurized module (530) to form a laminate thereon.

[0108] One or more temperature and / or pressure applications may be used for the formation of the laminate disclosed in this document. For example, one or more temperature profiles may be used along the longitudinal length of the belt in the double belt press (500). In some embodiments, one or more of the temperature or pressure applied by the double belt press may be constant along its longitudinal length. The pressure P1 may be less than about 100 bar, for example, about 10 to about 90 bar, about 10 to about 30 bar, about 25 bar to about 70 bar, about 60 to about 90 bar, about 30 to about 80 bar, about 60 to about 80 bar, about 50 to about 70 bar, or less than about 80 bar. In one embodiment, the pressure is constant during the process, and in some embodiments, during any heating and cooling steps. The pressure may be between about 30 and about 80 bar, preferably about 70 bar.

[0109] The layup of individual layer films of the laminate (100) is heated to a selected temperature and pressed to a selected pressure in a double belt press (500) to form the laminate (100). The laminate (100) may be further processed to form a container shell or a travel bag shell, such as a panel. For example, the laminate may be used to form a travel bag shell, etc. in a molding device.

[0110] FIG. 6a is an isometric perspective view of a forming device (640) according to at least some embodiments. The forming device (640) may include a lining feeder (642), a press (644), and a heater array (646). In some embodiments, the lining feeder (642) receives and distributes a fabric sheet, such as a mesh, knit, woven, or non-woven fabric, to be formed together with a laminate (100) (Fig. 1) sheet. The fabric sheet may serve as an inner lining for a suitcase shell produced by the forming device (640). The fabric sheet may be received and stored in a tray (648) before being distributed to the laminate (100) sheet.

[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 the male mold (654) of a deep drawing tool (656). In FIG. 6, a portion of the upper table (650) has been removed to show the male mold (654) more clearly. The lower table (652) may support a lower mold, which may be the female mold (658) of a deep drawing tool (656). The tables (650, 652) are movable relative to each other. The molds (654, ​​658) are complementary to each other so that one mold, e.g., the male mold (654), is fitted at least partially inside another mold, e.g., the female mold (658). A certain amount of clearance may be provided between the molds to account for the thickness of the formed product. The molds (654 and 658) may be configured to make travel bag shells, container shells, panels, etc.

[0112] The press (644) further includes a sheet gripping rack (664). The rack (664) is configured to controllably hold each laminate (100) sheet in a position between the receiving die (654) and the female die (658). The rack (664) may also be configured to stretch or apply tensile force to the laminate (100) sheet. The application of tensile force or pressure may help to more firmly integrate the films of the laminate (100) with one another. The tensile force or pressure applied to the laminate (100) may be less than about 5 bar, for example, about 0.5 to about 4 bar, about 0.5 to about 3 bar, about 0.5 to about 2 bar, or about 1.5 to about 2 bar.

[0113] FIG. 6b is a perspective view of a sheet gripping rack (664) according to one embodiment. FIG. 6c is a perspective view of a gripping bar (665) of a gripping rack (664) according to one embodiment. As illustrated in FIG. 6b, the gripping rack (664) may include upper and lower gripping bars (631 and 632) for gripping a laminated material or a travel bag shell, a support rod (612) for supporting a layup or laminated material, and one or more jaw actuation drive units (633). The jaw actuation drive unit (633), which drives the upper and lower gripping bars (631, 632) (or jaws) in response to each process control via a link mechanism (e.g., a toggle lever mechanism), may operate on an electric, pneumatic, or hydraulic basis.

[0114] Accordingly, the sheet gripping rack (664) is configured to support and hold the laminated material or the molded travel bag shell before, during, and after applying pressure to the laminated material. The sheet gripping rack (664) is also configured to apply a selected amount of tensile force to the laminated material (e.g., sheet) or the travel bag shell during processing in the press (644). In some embodiments, no tensile force may be applied, and the sheet gripping rack (664) may simply hold the laminated material.

[0115] Referring again to FIG. 6a, a sheet of laminate (100) can be introduced into the press (644) from a sheet feed section at the back of the press (644) (as seen in FIG. 6a). The laminate (100) is held between the receiving die (654) and the female die (658) by a sheet gripping rack (664). For example, the top and / or bottom surface of the laminate may be heated while the laminate is being held or stretched by the sheet gripping rack (664).

[0116] A heater array (646) can heat the laminate (100) sheet while it is held between the male and female molds (654, ​​658). The laminate (100, or layup) can be heated to a temperature high enough to melt, partially melt, or soften one or more of the outer layer (204), core (202), matrix layer (140-143), or at least one woven plastic material sheet (130 or 150) (Fig. 1). The laminate (100) may be preheated and / or heated to a temperature of about 40°C to about 190°C, e.g., 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 embodiments, if the laminate (100) is not fixed or held during preheating, it may be particularly helpful to preheat at a temperature lower than the shrinkage temperature of the material(s) within the laminate (100). For example, the preheating temperature may be about 50 to 60°C.

[0117] The press (644) is configured so that the molds (654, ​​658) quickly engage or close, which can help reduce the number of wrinkles that occur in the corners of deep-drawn items, such as travel bag shells. The molds (654, ​​658) may remain closed for about 15 to 45 seconds, about 15 to 30 seconds, about 30 to 45 seconds, about 20 to 35 seconds, about 30 to 45 seconds, less than 1 minute, less than 40 seconds, or about 30 seconds.

[0118] The molding device (640) can output a travel bag shell, etc., including a laminate (100) (Fig. 1). FIG. 7a is a front isometric perspective view of a lid shell (722) of a travel bag shell (720) according to at least some embodiments. FIG. 7b is a rear isometric perspective view of a base shell (734) of a travel bag shell (720) according to at least some embodiments, and together they form a travel bag case (750) (see FIG. 7c). A travel bag shell (720), such as a suitcase shell, may be composed of the laminate (100) disclosed in this document. The travel bag shell (720) may be in the form of a lid shell (722) (Fig. 7a) or a base shell (734) (Fig. 7b).

[0119] One or more sides may include surface features (748). The features (748) may be concave areas such as grooves (747) and convex areas such as ribs (749). In addition to being aesthetically pleasing, the features (748) may provide rigidity or resistance to bending or distortion forces applied to the shell (720, 734).

[0120] One or both of the lead shell (722) and the base shell (734) may be deep drawn such that the depth of the lead shell (722) or the base shell (734) is significantly larger than the length or width.

[0121] Any travel bag shell described in this document may be used to form the body of a travel bag, such as a hard-sided travel bag case. FIG. 7c is an isometric view of a hard-sided travel bag case (750) according to at least one embodiment. The hard-sided travel bag case (750) is defined by a lead shell (722) and a base shell (734) being operably joined to form a housing (752) by an outer layer. Either or both of the lead shell (722) and the base shell (734) may be produced by any of the methods described above.

[0122] The travel case (750) may also include a sealing mechanism such as a zipper, and the travel case (750) is divided into a lead shell (722) and a base shell (734) by defining a sealing line (770). A hinge (not shown) for rotatably connecting the lead shell (722) and the base shell (734) is located along the sealing line (770). The sealing mechanism may include a latch, a button, a strap, etc.

[0123] The travel bag case (750) may also include two or more wheels (772), one or more carrying handles, and an extendable pull handle (not shown).

[0124] Travel bag cases having different surface features and aesthetic appearances can be made using the laminate disclosed in this document. For example, a travel bag case having a substantially flat surface can be made of the laminate (100).

[0125] FIG. 8 is a diagram of a method (800) for manufacturing a travel bag shell according to at least some embodiments. The method (800) includes the step of forming a layup (810), the step of laminating the layup under constant pressure in a press (820), and the step of forming the laminated layup into a travel bag shell (830). The method (800) may include more or fewer steps than steps (810-830). For example, any of steps (810-830) may be divided into a series of smaller steps. In some embodiments, the method (800) may include the step of assembling the travel bag shell into a travel bag.

[0126] The step of forming a layup (810) may include forming a layup according to any laminate disclosed herein. For example, the layup may include one or more of a first set of BOPP films, a second set of BOPP films, a third set of BOPP films, at least one sheet of woven plastic material, or at least one matrix layer as disclosed herein. The step of forming a layup may include arranging film layers in any order disclosed herein. For example, the step of forming a layup may include combining individual film layers into a layup by feeding films from each film roll in a continuous or batch feeding process, such as using a double belt press. The layup may have any characteristics of the layup or laminate disclosed herein, such as composition, thickness, melting point, etc.

[0127] The step (820) of laminating the layup under uniform pressure in a press may include exposing the layup to a selected pressure or temperature for any period of time in an isobaric double belt press. For example, a pressure of about 10 bar to about 90 bar (e.g., about 30 bar to about 70 bar) may be applied while applying a first temperature of about 90°C to about 180°C so that one or more components of the layup are at least partially melted or softened. The step of laminating the layup under uniform pressure may further include a step of cooling the laminate to a second temperature (e.g., room temperature) lower than the first temperature so that the film layers within the layup can be cooled and bonded to form a laminate (100).

[0128] The step of stacking layups under uniform pressure may include feeding the layups to an isostatic press at a selected feed rate, such as any feed rate disclosed in this document. The step of stacking layups may include utilizing the isostatic press in any manner disclosed in this document to form a laminate (100) (Fig. 1).

[0129] The step (830) of forming a stacked layup into a travel bag shell using a plug cavity mold may include feeding any laminate disclosed herein to a forming device (640) (Fig. 6). The step of forming a stacked layup into a travel bag shell using a plug cavity mold may include utilizing the forming device in any manner disclosed herein to form a travel bag shell. For example, the step of forming a stacked layup into a travel bag shell using a plug cavity mold may include the step of fixing and / or tensioning the laminate using a sheet gripping rack, the step of heating the laminate, or the step of pressing the laminate within the mold cavity with any pressure disclosed herein. The plug cavity mold includes a deep drawing mold having a male mold and a female mold half.

[0130] The step of forming the laminated layup into a travel bag shell may include using other forming or forming techniques such as hydraulic forming, extrusion, manual operation, etc.

[0131] The step of forming a molded travel bag shell may further include the step of forming a travel bag, such as a wheeled travel bag, using the travel bag shell. The wheeled travel bag may have one or more wheels, one or more handles (774), one or more extendable handles (774), and at least one sealing mechanism (e.g., a zipper, a clip, a strap, a button). In this embodiment, the step of forming a travel bag using the travel bag shell may include the step of assembling facing travel bag shells, the step of attaching one or more sealing mechanisms, the step of attaching a set of wheels, the step of attaching one or more hinges, or the step of attaching one or more straps, extendable handles, etc., forming any travel bag disclosed herein.

[0132] The laminate having the woven plastic material sheet disclosed in this document provides superior physical properties, such as stiffness, tensile strength, strain at break, and high bond strength, even in relatively thin configurations compared to similar laminates without the woven plastic material sheet. Furthermore, the laminate having the woven plastic material sheet disclosed in this document possesses greater stiffness and resilience compared to similar laminates without the woven plastic material sheet. To demonstrate the advantages of the laminate disclosed in this document, operating embodiments were formed and tested.

[0133] Examples

[0134] Example 1:

[0135] To provide Example 1, a laminate was formed according to Table 1 below. The laminate of Example 1 was formed in an isostatic press.

[0136]

[0137] Comparative Example A:

[0138] To provide Comparative Example A, a laminate was formed according to Table 2 below. The laminate of Comparative Example A was formed in an isostatic press.

[0139]

[0140] Comparative Example B:

[0141] To provide Comparative Example B, a laminate was formed according to Table 3 below. The laminate of Comparative Example B was formed in an isostatic press.

[0142]

[0143] Comparative Example C:

[0144] To provide Comparative Example C, a laminate was formed according to Table 4 below. The laminate of Comparative Example C was formed in an isostatic press.

[0145]

[0146] The laminates of Example 1, Comparative Example A, Comparative Example B, and Comparative Example C (see Table 4 above) had similar thicknesses. Tests were performed to determine physical properties (e.g., mechanical properties) for Example 1, Comparative Example A, Comparative Example B, and Comparative Example C. Specifically, tensile tests, impact resistance tests, stiffness tests, resilience tests, peel tests, and three-point bending tests were performed on the above examples.

[0147] Tensile tests and resilience tests were performed on the laminates according to Example 1, Comparative Example A, and Comparative Example B as described below.

[0148] Four samples according to Example 1, Comparative Example A, and Comparative Example B, respectively, were cut into rectangles of the same size (25 mm x 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 on an Instron 5985 test apparatus equipped with a 30 kN load cell. Mechanical vise grips (e.g., clamps) were used to secure the samples within the test apparatus. Sandpaper was used as the end tabs of the samples to prevent slippage from the mechanical vise grips. The samples were tested at a gauge length of 150 mm. The strain rate was 6% / min.

[0149] Tensile strength, stress, strain, and resilience characteristics were calculated from the tensile test results.

[0150] The average surface strain was calculated using digital image correlation. The tensile modulus was calculated as the slope of the stress-strain curve between strains of 0.1% and 0.3%. The restoring force was calculated as the area under the stress-strain curve up to the yield point. The yield point was determined using the 0.2% offset method. Tensile strength is the highest point on the stress-strain curve, and the corresponding strain is the fracture strain.

[0151] Figures 9a and 9b are graphs showing the tensile modulus (Young's modulus) test results of the examples in the machine direction (MD) and transverse direction (TD), respectively. As shown in Figure 9a, Comparative Example A (indicated as CEA in Figures 9a to 10b) recorded a Young's modulus (E) of about 2.5 gigapascals (GPa) in the machine direction and showed the lowest tensile modulus, Example 1 (indicated as WE1 in Figures 9a to 10b) recorded an E value of about 2.8 GPa and had a higher tensile modulus in the machine direction than Comparative Example A, and Comparative Example B (indicated as CEB in Figures 9a to 10b) had the highest tensile modulus in the machine direction with an E value of about 3.1 GPa. As shown in Fig. 9b, Comparative Example B recorded the lowest tensile modulus with an E value of about 3.1 GPa in the transverse direction, Example 1 had a higher tensile modulus in the transverse direction than Comparative Example B with an E value of about 4.3 GPa, and Comparative Example A had the highest tensile modulus in the transverse direction with an E value of about 4.7 GPa.

[0152] Figures 10a and 10b are graphs showing the results of the resilience test of the examples in the machine direction and transverse direction, respectively. The examples were tested according to the protocol disclosed above in relation to the tensile test summarized in Figures 9a and 9b, and the resilience characteristics were also determined from the tensile test as described above. Resilience is a criterion for the amount of energy a material can absorb without plastic or permanent deformation. As shown in Figure 10b, Comparative Example B exhibited the lowest resilience, recording a resilience of approximately 0.08 MJ / m³ in the transverse direction, while Example 1 had a higher resilience in the transverse direction than Comparative Example B with a resilience of approximately 0.17 MJ / m³, and Comparative Example A had the highest resilience in the transverse direction (slightly higher than Example 1) with a resilience of approximately 0.18 MJ / m³. As shown in FIG. 10a, Comparative Example B exhibited the lowest restoring force, recording approximately 0.8 MJ / m³ in the machine direction, Comparative Example A had a higher restoring force in the lateral direction than Comparative Example B with approximately 0.14 MJ / m³, and Example 1 had the highest restoring force in the lateral direction with approximately 0.16 MJ / m³. Example 1 showed the highest combined restoring force (in both directions) and demonstrated superior performance compared to the materials of the Comparative Examples in terms of restoring force or impact resistance in "real-world situations."

[0153] The three-point bending test (used to calculate flexural modulus properties) was performed according to the standard ASTM D7264 "Flexural properties of polymer matrix composites". For each example laminate, five rectangular samples measuring 13 mm x 50 mm were formed and tested in both the machine direction and the transverse direction. The three-point bending test was performed on an Instron 5943 test machine equipped with a 100 N load cell.

[0154] Figures 11a and 11b are graphs showing the results of the flexural modulus test in the machine direction and the transverse direction, respectively. As shown in Figure 11a, Comparative Example B exhibited the highest flexural modulus in the machine direction with a flexural modulus of approximately 3.3 GPa, Example 1 had a higher flexural modulus in the machine direction than Comparative Example A with a flexural modulus of approximately 2.4 GPa, and Comparative Example A had the lowest flexural modulus in the machine direction with a flexural modulus of approximately 1.8 GPa. As shown in Figure 11b, Comparative Example A exhibited 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, and 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 increases the design freedom of cases (e.g., suitcases) using the laminate of Example 1 compared to comparative examples. For example, the stiffer material of Example 1 allows for the omission of certain geometric configurations used for structural stiffness.

[0155] Further tests were conducted on the effect of adding woven plastic material sheets to a laminate beyond just two layers. For example, flexural modulus and tensile tests were performed on laminates having two and four woven plastic material sheets according to Example 1. The results of the flexural modulus and tensile strength (e.g., stiffness) tests showed no substantial difference in bending stiffness and strength in the transverse direction of the laminate, and only a slight increase in bending stiffness and strength was observed in the machine direction. However, even the increase observed when using four woven plastic material sheets was not as significant as the increase in bending stiffness and strength observed when using two sheets instead of no woven plastic material sheets. Therefore, adding more than two woven plastic material sheets to a laminate is expected to result in diminishing returns.

[0156] As a result of the test, Example 1 was proven to maintain excellent tensile strength and flexural properties in both the machine direction and the transverse direction, and to maintain excellent resilience in both the machine direction and the transverse direction. Therefore, a travel bag shell made from the laminate of Example 1 is expected to provide a travel bag that is lightweight, strong, durable, and resistant to deformation.

[0157] The laminates according to Example 1, Comparative Example A, and Comparative Example B were formed into travel bags having the same structure and dimensions. The laminates of Example 1, Comparative Example A, and Comparative Example B were formed in an isostatic press and then finally formed into top (e.g., front) and bottom (e.g., rear) travel bag shells in a cavity plug mold and assembled into a suitcase. The laminates for Example 1, Comparative Example A, and Comparative Example B had substantially similar thicknesses. For each example, the weight of the top and bottom shells was recorded.

[0158]

[0159] As shown in Table 5, the travel bag shells formed by Example 1, Comparative Example A, and Comparative Example B also had substantially similar weights.

[0160] Compression tests were performed on the travel bags formed from the laminates according to Example 1, Comparative Example A, Comparative Example B, and Comparative Example C to determine the stiffness of the examples. These tests determine the rigidity (e.g., stiffness) of the travel bags when force is applied to the top of the assembled travel bag case, such as when a user sits on the top panel. The travel bags formed from the laminates according to Example 1, Comparative Example A, Comparative Example B, and Comparative Example C had the same structure, dimensions, and components (e.g., wheels and zippers). Carrying handles, logos, and pull handles were not installed on the examples.

[0161] For the test, each suitcase was placed on a tensile testing machine with the wheels facing downward on a flat surface and the zipper connecting the two shells. To exclude small deformations already present in the suitcase shells, the displacement was recorded as zero at the point where an initial force of 50 Newtons (N) was applied. Subsequently, the compressive force was steadily increased until a selected amount of displacement was observed. The selected displacements were 8 mm, 16 mm, and 20 mm. For each example, the force required to reach the selected displacement was recorded. The stiffness test results for each example are shown in Table 6 below.

[0162]

[0163] As shown in Table 6, Example 1 showed the highest load required for displacement as the amount of displacement increased, and at a displacement level of 20 mm, it demonstrated performance that surpassed all other examples alone.

[0164] Therefore, at least some of the embodiments disclosed in this document have higher rigidity than other laminates used in travel bags.

[0165] For the material combinations used in Example 1, peel tests were performed while varying the combination of SRPP material, BOPP material, and matrix material, as well as the temperature at which the materials are bonded. Specifically, a T-peele test was performed according to the standard ASTM D1876-08.

[0166] For testing, ten rectangular samples measuring 250 mm x 20 mm were cut from 0.6 mm thick panels for each material combination (only two samples were used for the BOPP and PP combination bonded at 125 °C, and ten for each of the others), with a length of 76 mm at one end left unbonded. During sample preparation, a release film was inserted into the stack between the layers to be tested to prevent one side of the sample panel from being bonded. The T-section of the sample combination was formed by securing each material to opposite clamps and pulling in opposite directions to determine the peel strength of the bond between the materials. These samples were tested on an Instron 5943 test machine by grasping the ends and pulling at a speed of 254 mm / min. Peel strength was calculated according to the ASTM D1876-08 test procedure by normalizing the average peel load after the first initial peak by dividing it by the width.

[0167] Specific sample combinations (SC) were formed using various material combinations in adjacent layers of a stack at various bonding temperatures including 125 °C, 130 °C, 140 °C, and 150 °C. Some sample combinations (SC) were fabricated using an MAPP matrix layer instead of a PP matrix layer bonded to BOPP or SRPP. These sample combinations include the materials specified in Example 1. The materials for the sample combinations for the T-peeling test are described in Table 7 below.

[0168]

[0169] Don & Low 1 and Don & Low 2 differ in their melting points, with Don & Low 1 having a melting point in the range of 140 to 145°C and Don & Low 2 having a melting point in the range of 125 to 130°C.

[0170] Figure 12 is a graph showing the results of the T-peel test. As shown in Figure 12, SC1 showed an average peel strength of approximately 0.78 Newtons / millimeter (N / mm), SC2 showed approximately 0.56 N / mm, SC3 showed approximately 0.78 N / mm, SC4 showed approximately 0.67 N / mm, SC5 showed approximately 0.78 N / mm, SC6 showed approximately 0.50 N / mm, SC7 showed approximately 0.87 N / mm, SC8 showed approximately 0.46 N / mm, SC9 showed approximately 0.87 N / mm, SC10 showed approximately 0.72 N / mm, SC11 showed approximately 0.67 N / mm, and SC12 showed an average peel strength of approximately 0.73 N / mm.

[0171] The T-peele test results show the bonding strength between materials of sample combinations SC1–SC12 expressed as peel strength. The results for SC8 demonstrate that the direct bonding between BOPP and SRPP is the weakest among the sample combinations, followed closely by the SRPP-to-SRPP bonding in SC6. The test results for SC10 show that the BOPP-to-PP bonding is stronger than the BOPP-to-SRPP bonding (even at a relatively low temperature of 125°C). The SRPP-to-MAPP bonding in SC11 and SC12 was also stronger than the SRPP-to-SRPP bonding in SC6 and the SRPP-to-BOPP bonding in SC8. Furthermore, all SRPP-to-PP bonding in SC2, SC3, SC5, SC7, and SC9 was stronger than the SRPP-to-BOPP bonding in SC8 and the SRPP-to-SRPP bonding in SC6. The BOPP-to-MAPP bonding in SC1 and SC4 was also stronger than the SRPP-to-BOPP bonding and the SRPP-to-SRPP bonding.

[0172] Based on the T-peeling test, placing a PP film (PP or MAPP) between an SRPP fabric (Don & Low 1 or Don & Low 2) and a BOPP film increases the bonding strength between the materials compared to directly bonding the SRPP and BOPP.

[0173] In SC2, SC5, and SC9, the bonding strength between SRPP and PP was shown to increase as the bonding temperature increased. Similarly, in SC3 and SC7, the bonding strength between SRPP and PP was also shown to increase as the bonding temperature increased.

[0174] Additional T-peeling tests were performed according to the methods presented above.

[0175] Additional SCs were formed using various material combinations on 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 sample combinations (SCs) were fabricated using an MAPP matrix layer instead of a PP matrix layer bonded to BOPP or SRPP. These SCs include the materials specified in Example 1. The materials for the SCs for the T-peeling test are described in Table 7 below.

[0176] The materials for the SCs for the additional T-peeling test are described in Table 8 below.

[0177]

[0178] Figure 13 is a graph showing the results of an additional T-peeling test. As shown in Fig. 13, SC13 showed an average peel strength of about 1.1 N / mm, SC14 about 1.05 N / mm, SC15 about 0.6 N / mm, SC16 about 1.25 N / mm, SC17 about 1.22 N / mm, SC18 about 0.8 N / mm, SC19 about 0.8 N / mm, SC20 about 0.5 N / mm, SC21 about 0.48 N / mm, SC22 about 1.5 N / mm, SC23 about 1.2 N / mm, SC24 about 0.88 N / mm, SC25 about 0.75 N / mm, SC26 about 0.66 N / mm, SC27 about 0.5 N / mm, SC28 about 1.4 N / mm, and SC29 about 0.45 N / mm.

[0179] The results of additional T-peeling tests show the bond strength between materials of sample combinations SC13-SC29 expressed as peel strength. The results for SC21, SC27, and SC29 demonstrate 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 SRPP (Don & Low 2)-to-PP bond formed at 130 °C is the next weakest. The BOPP-to-MAPP bond 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-MAPP bonds of SC18 and SRPP-PP bonds of SC19, both formed at 140 °C, are nearly equivalent to the SRPP-MAPP bonds of SC25 formed at 150 °C. The BOPP-MAPP bonds of SC13 and SC14, formed at 125 °C, have higher bond strengths than SC15, SC18-SC21, SC24-27, and SC29.

[0180] The BOPP-to-PP bonds of SC13, SC17, and SC23 formed at 125 °C, 140 °C, and 150 °C, respectively, were stronger than all 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.

[0181] Based on additional T-peeling tests, when a PP film (PP or MAPP) is placed between an SRPP fabric (Don & Low 2) and a BOPP film at all tested forming temperatures, the bonding strength between the materials increases compared to directly bonding the SRPP and BOPP.

[0182] In SC15, SC18, and SC24, the bonding strength between SRPP and PP was shown to increase as the bonding temperature increased.

[0183] FIG. 14 is a graph of the temperature profile of a laminate according to Example 1 (WE1). The temperature profile used in the lamination process of WE1 differs in the temperature passing through two zones within an isostatic press. Profile 1 includes a temperature of 155 °C in the first zone and 145 °C in the second zone. Profile 2 includes a temperature of 170 °C in the first zone and 155 °C in the second zone.

[0184] As used in this document, the term "about" includes values ​​within ±5% of the value modified by the term "about".

[0185] In this document, references to standards such as ASTM or ISO standards refer to each standard as of the filing date of this application.

[0186] The present invention may be embodied in other specific forms without departing from its spirit or essential nature. The described embodiments are illustrative in all respects and should be considered not restrictive. Accordingly, the scope of the invention is defined by the appended claims rather than by the foregoing description. Any modifications within the meaning and equivalent scope of the claims shall be included therein. Explanation of the symbols

[0187] 100 laminates 102 External Surface 104 Internal Surface 110 BOPP film of the first set 112, 114, 118 BOPP film 120 BOPP film of the 2nd set 122, 124, 128 BOPP film 130, 150 woven plastic material sheets 140, 141, 142, 143 Matrix Layer 141 Matrix Layer 180 BOPP film of the 3rd set 182, 184, 188 BOPP film 200 torn BOPP film 202 core layer 203 Top surface 204 outer floor 205 bottom surface 206 External Surface 208 inner surface 210 laminates 300 Broken Extrusion Tape 302 core layer 304 outer floor 400 woven plastic material sheets 402, 404 woven polymer tape 500 Double Belt Press 510 Lower Press Assembly 511 lower belt 520 Upper Press Assembly 521 upper belt 530 Lower Pressurization Module 531 Lower pressurized body 532, 534, 536 column elements 540 Upper Pressurization Module 541 Upper pressurized body 542, 544, 546 column elements 612 support rod 631 Upper Griping Bar 632 Lower Griping Bar 633 operating drive unit 640 forming device 642 Lining Feeder 644 Press 646 Heater Array 648 Tray 650 upper table 652 lower table 654 Collector type 656 Deep Drawing Tools 658 Female mold 664 Sheet Griping Rack 665 Griping Bar 720 travel bag shell 722 Lead Shell 734 Base Shell 747 Groove 748 Surface features 749 Concave areas and ribs 750 travel suitcase 770 sealed line 772 wheels 774 handle 800 methods Steps to form an 810 layup Step of stacking 820 layups Molding 830 layup into a travel bag shell

Claims

Claim 1 A travel bag shell (720, 722, 734) formed by a laminate (100, 210), wherein the laminate (100, 210) comprises: a first set of biaxially stretched polypropylene (BOPP) films (110) having at least one film comprising a co-extruded film comprising a core (202, 302) of a thermoplastic polymer and at least one outer layer (204) of a thermoplastic polymer; a second set of BOPP films (120) comprising a core (202, 302) of a thermoplastic polymer and at least one outer layer (204) of a thermoplastic polymer; and at least one woven plastic material sheet (130, 150, 400) disposed between the first set of BOPP films (110) and the second set of BOPP films (120). A travel bag shell comprising at least one matrix layer (140, 141, 142, 143) disposed on at least one surface of at least one of the at least one woven plastic material sheet (130, 150, 400). Claim 2 A travel bag shell according to claim 1, further comprising a third set of BOPP films (180) disposed 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) comprises: a first woven plastic material sheet (130, 150, 400) disposed between the first set of BOPP films (110) and the third set of BOPP films (180); and a second woven plastic material sheet (130, 150, 400) disposed between the second set of BOPP films (120) and the third set of BOPP films (180). Claim 3 A travel bag shell according to claim 2, wherein the at least one matrix layer (140, 141, 142, 143) comprises a first matrix layer (140, 141, 142, 143) disposed on the upper surface of the first woven plastic material sheet (130, 150, 400), a second matrix layer (140, 141, 142, 143) disposed on the lower surface of the first woven plastic material sheet (130, 150, 400), and a third matrix layer (140, 141, 142, 143) disposed on the upper surface of the second woven plastic material sheet (130, 150, 400). Claim 4 A travel bag shell according to claim 2 or 3, wherein the first set of BOPP films (110) comprises 1 to 10 BOPP films; the second set of BOPP films (120) comprises 1 to 10 BOPP films; and the third set of BOPP films (180) comprises 1 to 20 BOPP films. Claim 5 In any one of claims 2 to 4, the first set of BOPP films (110) comprises 3 to 5 BOPP films; the second set of BOPP films (120) comprises 3 to 6 BOPP films; and the third set of BOPP films (180) comprises 7 to 14 BOPP films; A travel bag shell comprising at least one matrix layer (140, 141, 142, 143) disposed on the upper surface of the first woven plastic material sheet (130, 150, 400), a second matrix layer (140, 141, 142, 143) disposed on the lower surface of the first woven plastic material sheet (130, 150, 400), and a third matrix layer (140, 141, 142, 143) disposed on the upper surface of the second woven plastic material sheet (130, 150, 400). Claim 6 In claim 1, the invention further comprises a third set of BOPP films (180) disposed 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) comprises: a first woven plastic material sheet (130, 150, 400) disposed 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) disposed between the second set of BOPP films (120) and the third set of BOPP films (180); and a third woven plastic material disposed between the first woven plastic material sheet (130, 150, 400) and the second woven plastic material sheet (130, 150, 400). Sheet(130, 150, 400); and includes a fourth woven plastic material sheet (130, 150, 400) disposed between the third woven plastic material sheet (130, 150, 400) and the second woven plastic material sheet (130, 150, 400); and the at least one matrix layer (140, 141, 142, 143) comprises a first matrix layer (140, 141, 142, 143) disposed on the upper surface of the first woven plastic material sheet (130, 150, 400), a second matrix layer (140, 141, 142, 143) disposed on the upper surface of the second woven plastic material sheet (130, 150, 400), and a third matrix layer (140, disposed on the upper surface of the third woven plastic material sheet (130, 150, 400). A travel bag shell comprising 141, 142, 143), and a fourth matrix layer (140, 141, 142, 143) disposed on the upper surface of the fourth woven plastic material sheet (130, 150, 400). Claim 7 A travel bag shell according to any one of claims 2 to 6, wherein 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); and the third set of BOPP films (180) has a thickness of 35% to 45% of the total thickness of the laminate (100, 210). Claim 8 A travel bag shell 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). Claim 9 A travel bag shell 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. Claim 10 A travel bag shell 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-reinforcing polypropylene (SRPP) sheet. Claim 11 In any one of claims 1 to 10, the at least one woven plastic material sheet (130, 150, 400) comprises a plurality of longitudinally stretched polypropylene tapes arranged in a selected weaving pattern; and the selected weaving pattern can be seen through the first set of BOPP films (110), a travel bag shell. Claim 12 In any one of claims 1 to 11, 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), or the second set of BOPP films (120) comprise a coloring agent; and the coloring agent may be at least partially visible through the first set of BOPP films (110), a travel bag shell. Claim 13 A travel bag shell according to any one of claims 1 to 12, wherein 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; and the color intensity when viewed from the outermost surface of the laminate (100, 210) is higher than that of the laminate (100, 210) of the same configuration that does not include the innermost BOPP film which is white. Claim 14 A travel bag case comprising: at least one travel bag shell (720, 722, 734) according to any one of claims 1 to 13; one or more handles (774) attached to the at least one travel bag shell (720, 722, 734); and a plurality of wheels (772) attached to the at least one travel bag shell (720, 722, 734). Claim 15 A method for manufacturing a travel bag shell (720, 722, 734), comprising: a step of forming a layup according to a laminate (100, 210) according to any one of claims 1 to 13; a step of laminating the layup under uniform pressure in an isostatic press; and a step of forming the laminated layup into a travel bag shell (720, 722, 734) using a plug cavity mold.

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