Sealable polypropylene FIBC and FIBC parts

Abstract

The invention relates to sealable polypropylene (FIBC) and FIBC parts. A sealable fabric (1) for a flexible intermediate bulk container (FIBC) containing bulk material comprises a woven fabric (10) comprising polypropylene, a coating (20) comprising polypropylene, and a sealable film (30) comprising sealable polypropylene, in particular a sealable polypropylene resin.

Description

Technical Field

[0001] This invention relates to sealable fabrics and flexible intermediate bulk containers (FIBCs) made from sealable fabrics. Background Technology

[0002] Flexible intermediate bulk containers (FIBCs), or large bags, are industrial containers made of flexible fabric designed for storing and transporting dry and / or flowable products such as sand, fertilizer, or pellets. FIBCs typically have a filling volume of about 1000 l-1300 l and can be filled to about 1000 kg-1500 kg.

[0003] FIBCs, or large bags, consist of multiple woven fabrics made of polypropylene. Such woven polypropylene fabrics are high-strength and chemically inert. During the manufacture of FIBCs or large bags, the woven polypropylene fabrics are typically sewn together. However, sewing reduces the strength of the woven polypropylene fabrics by needle punching and thus damaging the fabric. Furthermore, sewing can lead to leakage and contamination problems, and it is often a time-consuming process, such as manual sewing. FIBCs or large bags typically include a liner (e.g., a liner containing low-density polyethylene (LDPE)) to protect the filled product. The liner is usually secured to the FIBC or large bag by adhesive or by using tape. Depending on the filling conditions of the FIBC, securing the liner may be separate, and / or handling FIBCs with liners is more difficult than handling FIBCs without liners.

[0004] US 2014 / 0363106 A1 teaches an alternative method for producing flexible polypropylene fabrics, wherein the polypropylene fabric comprises coated sides and uncoated sides. During manufacturing, the coated sides of two polypropylene fabrics are bonded together by applying heat to the polypropylene fabrics.

[0005] The object of this invention is to provide a sealable fabric for FIBCs that has improved properties for manufacturing FIBCs and reducing the risk of contamination and leakage.

[0006] This problem is solved by the sealable fabric according to claim 1 and the flexible intermediate bulk container (FIBC) according to claim 14. Summary of the Invention

[0007] According to the present invention, a sealable fabric is provided for use in flexible intermediate bulk containers (FIBCs) or large bags for containing bulk materials. The sealable fabric comprises: a woven fabric containing polypropylene, particularly additional sealable polypropylene; a coating containing polypropylene, particularly additional sealable polypropylene; and a sealable film containing sealable polypropylene, particularly a sealable polypropylene resin. Thus, the sealable fabric is specifically formed from different layers: a first layer containing the woven fabric, a second layer containing the coating, and a third layer containing the sealable film.

[0008] Preferably, a coating is provided between the woven fabric and the sealable film to bond the woven fabric and the sealable film. The sealable film provides the effect of sealing the sealable fabric to another sealable fabric by means of sealing technology. The sealable fabric can be sealed, in particular, by applying heat to the sealing area of ​​the sealable fabric. Therefore, the sewing operation can be eliminated. Due to the sealing process, the sealable fabric is not damaged, thus providing high strength of the joined sealable fabrics. Additionally, the main component of the sealable fabric is polypropylene. Therefore, the entire sealable fabric can be easily recycled, thus providing a high degree of sustainability. In particular, the woven fabric is the load-bearing layer of the sealable fabric.

[0009] A sealable structure and / or material, particularly PP and / or PE, can be sealed, especially by applying a temperature at least equal to the material's melting point, preferably at least 10°C above the melting point, and even more preferably at least 20°C above the melting point, and / or by applying a temperature of at least 80°C, optionally at least 100°C, even more preferably at least 140°C, even more preferably at least 160°C, even more preferably at least 200°C, and / or below 300°C, optionally below 200°C. Most preferably, a temperature of 100°C to 200°C is used for sealing.

[0010] The structure according to the invention exhibits particularly good sealability, resulting from a specific combination of polypropylene-based materials with complementary thermal and rheological properties. The sealable polypropylene resin provides a low seal initiation temperature and moderate melt flow rate, thereby ensuring rapid surface melting and efficient chain interdiffusion at relatively low temperatures. The low-flow-rate polypropylene heterogeneous copolymer provides a high softening temperature and mechanical stability, thus preventing deformation and maintaining high seal integrity during the heat-sealing process.

[0011] Woven fabrics are made especially from warp and weft yarns.

[0012] In this embodiment, the woven fabric, particularly the yarn of the woven fabric, further comprises sealable polypropylene, particularly sealable polypropylene resin, and / or colorants and / or protective additives. Due to the sealable polypropylene, the adhesive strength between different layers of the sealable fabric can be improved during the sealing process. The protective additives can provide protection against ultraviolet (UV) radiation and / or against fabric tearing. Tear-resistant additives particularly include calcium carbonate. Therefore, the lifespan of the sealable fabric is increased. Preferably, the woven fabric, particularly the yarn of the woven fabric, does not contain polyethylene (PE).

[0013] In particular, woven fabrics, especially the yarns used in woven fabrics, contain the following components in proportion:

[0014] Polypropylene: 50%-70%, preferably 60%-65%; and / or

[0015] Crack-resistant additives: 2%-8%, preferably 4%-6%; and / or

[0016] Sealable polypropylene, particularly sealable polypropylene resin: 20%-40%, preferably 25%-35%; and / or

[0017] UV protective additives: 1%-2%, preferably 1.25%-1.75%; and / or

[0018] Colorant: 0.25%-0.75%.

[0019] Due to the high polypropylene content, woven fabrics offer high sustainability and can be easily recycled after use.

[0020] In the implementation scheme, the woven fabric has a density of 40 g / m². 2 -300 g / m 2 Especially 55 g / m 2 -250 g / m 2 75 g / m 2 -235 g / m 2 The weight provides sufficient strength for the woven fabric.

[0021] In another embodiment, the coating further comprises sealable polypropylene, particularly sealable polypropylene resin, and / or polyethylene, particularly linear low-density polyethylene (LLDPE). Specifically, the coating comprises the following components in the following proportions:

[0022] Polypropylene: 30%-60%, preferably 40%-50%; and / or

[0023] Polyethylene, particularly linear low-density polyethylene (LLDPE): 2%-8%, preferably 4%-6%; and / or

[0024] Sealable polypropylene resin: 35%-65%, preferably 45%-55%.

[0025] The coating preferably has a concentration of 15 g / m 2 -35 g / m 2 Especially 20 g / m 2 -30 g / m 2 The weight.

[0026] In the embodiments, the sealable membrane further comprises polyethylene, particularly linear low-density polyethylene (LLDPE) and / or low-density polyethylene (LD-PE) and / or low-flow polypropylene heterogeneous copolymers and / or tie material and / or sealable polypropylene, such as sealable polypropylene of C2 / C4 terpolymer.

[0027] Specifically, the sealable film comprises at least one first layer, such as an outer (outermost) layer, and / or at least one second layer, such as an inner layer, and / or at least one third layer, such as an adhesive layer. The layers of the sealable film can provide different mechanical and chemical properties, which can be adapted to the intended use of the sealable fabric. At least one first layer of the sealable film can be specifically adapted to the properties of adjacent layers, such as coatings and / or additional sealable films and / or sealable fabrics, to provide good adhesion. At least one second layer can preferably be adapted to improve the flexibility of the sealable film. At least one third layer particularly enhances the adhesion between the second and first layers. Preferably, the first layer surrounds the second and / or third layers such that the first layer forms the outer surface of the sealable film.

[0028] In this embodiment, the first layer of the sealable film comprises at least 80%, preferably at least 90%, and most preferably at least 98% sealable polypropylene, particularly a C2 / C4 terpolymer of sealable polypropylene, and / or sealable polypropylene resin and / or a low-flow polypropylene heterogeneous copolymer. Specifically, the first layer contains essentially only sealable polypropylene, particularly sealable polypropylene resin. Therefore, the adhesion between the sealable film and the sealable film of any additional sealable fabric, and / or the adhesion to the coating, can be enhanced.

[0029] In another embodiment, the second layer comprises polyethylene, particularly linear low-density polyethylene (LLDPE) and / or low-density polyethylene (LD-PE). Therefore, the elasticity of the second layer can be improved, thereby increasing the elasticity of the sealable film. Furthermore, the polyethylene component of the second layer can reduce the rigidity of the sealable film and / or increase its flexibility.

[0030] The third layer specifically comprises an adhesive material that enhances the adhesion between the second and first layers. Preferably, the third layer is located between the first and second layers.

[0031] Specifically, a sealable film is a co-extruded film, which allows a sealable film comprising a first and / or second and / or third layer to be manufactured in a single production step. A sealable film can also be considered as a barrier liner typically found in FIBCs or large bags, similar to a low-density polyethylene (LDPE) liner.

[0032] The sealable film is manufactured, in particular, by a multilayer blown film method or production line, preferably by a multilayer blown film co-extrusion method or production line, or by different extrusion production lines.

[0033] The sealable membrane can have a thickness of, for example, 30 μm-160 μm, particularly 30 μm-75 μm, preferably 35 μm-45 μm.

[0034] The aforementioned problems are particularly addressed by flexible intermediate bulk containers (FIBCs) or large bags for containing bulk materials, comprising at least one sheet of sealable fabric according to the invention. The sheet of sealable fabric forms a leak-proof, seamless or stitchless usable space or internal volume, having at least one main fabric or side element and a bottom element. At least one sheet of sealable fabric specifically forms at least one main fabric and / or bottom element and / or top element and / or loop structure, such as a handle, of the FIBC. Furthermore, at least one sheet of sealable fabric can be used for a filling port, particularly connected to the top element, and / or a discharge port, particularly connected to the bottom element, and / or an internal partition, particularly connected to at least one main fabric. Furthermore, the filling port and / or discharge port may each include at least one adhesive portion for closing the discharge port and / or filling port. Additionally, at least one sheet of sealable fabric can be used, particularly connected to the main fabric, as a skirt. Therefore, FIBCs are provided in which the sheets of sealable fabric are joined without any sewing operations. This avoids leakage and / or contamination problems associated with FIBCs or large bags. Furthermore, it simplifies the manufacturing process.

[0035] Preferably, at least one sheet of sealable fabric is sealed together in the sealing area, preferably along the edge of the FIBC. The fabric is sealed together, particularly by applying heat to the sealable membrane to melt it. The heat is applied, particularly by a heating element, induction heating, ultrasonic waves, or laser radiation.

[0036] The sealable fabric may preferably be used for all components of an FIBC or large bag, or for at least 50% by weight, preferably at least 90% by weight, of an FIPBC / large bag. Alternatively, the sealable fabric may be used for some components of an FIBC. The sealable fabric may be used in particular for filling ports and / or unloading ports and / or at least one skirt and / or at least one body fabric and / or bottom element and / or top element and / or bottom body and / or top body and / or vertical seals of filling ports and / or vertical seals of unloading ports and / or circular seals of filling ports to top elements and / or circular seals of unloading ports to bottom elements and / or, for example, to internal partitions of side bodies.

[0037] The sealable fabric can be additionally or alternatively used specifically for vertical sealing of the filling port and / or the discharge port and / or the skirt. Alternatively or additionally, the sealable fabric can be used to seal or weld the filling port to the top element and / or to seal or weld the filling skirt to the body element and / or to seal or weld the discharge port to the bottom element. Additionally or alternatively, the sealable fabric can be used to seal or weld the top element and / or the bottom element to the body fabric. Furthermore, the sealable fabric is preferably used to seal or weld the internal partition to the body fabric.

[0038] FIBCs or large bags have a usable space or internal volume of about 750 l to 1500 l, preferably about 1000 l to 1300 l. In particular, FIBCs or large bags have a capacity of 750 kg to 1750 kg, preferably 950 kg to 1550 kg. FIBCs or large bags, when empty, particularly have a weight of about 2 kg to 4 kg.

[0039] Sealing fabrics are specifically manufactured through the following manufacturing steps:

[0040] The yarn is produced, for example by a tape line, wherein the yarn preferably contains the components described above, and in particular the proportions of the components described above.

[0041] Fabrics are woven from yarns using warp and weft yarn techniques.

[0042] Sealable films are produced using multilayer blown film production lines, particularly multilayer blown film co-extrusion production lines.

[0043] Coating woven fabrics and sealable films to produce sealable fabrics.

[0044] Specifically, the percentages disclosed in this application refer to weight fractions or weight percentages (weight %). Therefore, a percentage can refer to the ratio of the mass of a component to the total mass of the mixture and / or layers and / or components.

[0045] The aforementioned problems are specifically addressed by a method for manufacturing a flexible intermediate bulk container (FIBC) for containing bulk materials, the method comprising providing at least one sheet of sealable fabric according to any of the preceding claims, wherein the FIBC is formed as follows: by sealing at least one fabric, a leak-proof, seamless usable space having at least one body fabric and a bottom element is formed, preferably wherein the sealing areas of at least one sheet of sealable fabric are sealed together. Attached Figure Description

[0046] The above and other features and advantages of the invention will become more readily apparent from the following detailed description of preferred embodiments of the invention with reference to the accompanying drawings, wherein like reference numerals denote like features, and wherein...

[0047] Figure 1 This is a schematic cross-sectional view of a sealable fabric;

[0048] Figure 2 This is a schematic diagram of weaving fabric;

[0049] Figure 3 This is a schematic cross-sectional view of a sealable membrane;

[0050] Figure 4 This is a schematic diagram of the FIBC according to the first implementation scheme;

[0051] Figure 5 yes Figure 4 A schematic diagram of the top component of the FIBC;

[0052] Figure 6 yes Figure 4 A schematic diagram of the bottom component of the FIBC; and

[0053] Figure 7 yes Figure 4 A schematic diagram of the interior of the FIBC. Detailed Implementation

[0054] Figure 1 Describes the sealable fabric 1 according to the present invention. Multiple sheets of the sealable fabric 1 are used to manufacture flexible intermediate bulk containers (FIBCs) or large bags for containing bulk materials. Figure 4 and 5 ).

[0055] The sealable fabric 1 includes a woven fabric 10, a coating 20, and a sealable film 30. The woven fabric 10 forms a first layer, the coating 20 forms a second layer, and the sealable film 30 forms a third layer of the sealable fabric. The coating 20 (i.e., the second layer of the sealable fabric 1) is sandwiched between the woven fabric 10 (i.e., the first layer of the sealable fabric 1) and the sealable film 30 (i.e., the third layer of the sealable fabric 1).

[0056] Both the woven fabric 10 and the coating 20 comprise polypropylene and a sealable polypropylene, respectively. The sealable film comprises sealable polypropylene. Due to the large amount of polypropylene in the coating 20, the adhesion between the woven fabric 10 and the sealable film 30 is enhanced. Therefore, delamination of the sealable fabric 1 is avoided.

[0057] according to Figure 2 The woven fabric 10 comprises a plurality of warp yarns 12 and weft yarns 11. The warp yarns 12 and weft yarns 11 are interlaced at substantially right angles. Therefore, the woven fabric 10 has high strength in the direction of the yarns 11, 12. Therefore, the woven fabric 10 forms the load-bearing layer of the sealable fabric 1. The yarns 11, 12 are made of a mixture comprising polypropylene, sealable polypropylene resin, colorant, crack-resistant additive, and ultraviolet (UV) protective additive. Therefore, the yarns 11, 12 are specifically made only of polypropylene with only a limited number of other components. Therefore, yarns 11, 12 with high strength and high resistance to environmental impact are provided.

[0058] Figure 3 A sealable film 30 is described. The sealable film 30 comprises two first layers 31, a second layer 33, and two third layers 32. The second layer 33 is located between the third layers 32. The third layers 32 and 33 are surrounded by the first layers 31, such that the third layers 32 and 33 are located between the first layers. Therefore, the first layer 31 forms the outer surface of the sealable film 30, preventing the second layers 33 and / or the third layers 32 from contacting the surrounding environment. The first layer 31 essentially comprises only sealable polypropylene, preferably a sealable polypropylene resin, to enhance adhesion to the woven fabric 10 and / or the coating 20.

[0059] The second layer 33 is the inner layer. The second layer 33 comprises linear low-density polyethylene (LLDPE) and / or low-density polyethylene (LD-PE). Due to the polyethylene component of the second layer 33, the rigidity of the sealable film 30 is reduced and / or the flexibility of the sealable film 30 is increased.

[0060] The first layer 31 and the second layer 33 are bonded together by using a third layer 32 located between the first layer 31 and the second layer. The third layer 32 contains an adhesive material to enhance the adhesion between the polypropylene of the first layer 31 and the polyethylene of the second layer 32. Therefore, delamination or other breakage of the sealable film 30 can be avoided.

[0061] Figure 4 The illustration shows a FIBC 2 or large bag according to a first embodiment of the present invention. The FIBC 2 comprises a plurality of main fabrics 7 forming the sidewalls of the FIBC 2, a bottom element 6, and a top element 9.

[0062] FIBC 2 additionally includes a filling port 9a connected to the top element 9 of FIBC 2, such as Figure 5As described in [the text].

[0063] In addition, a discharge port 6a is provided for connection to the bottom element 6 of FIBC 2, such as Figure 6 As shown in the image.

[0064] Additionally, a partition 7a is provided between two adjacent main fabrics 7 to enhance the stability of the FIBC 2 and / or provide a morphologically stable shape, such as Figure 7 As described in [the text].

[0065] Preferably, the main body fabric 7 and / or the bottom element 6 and / or the top element 9 and / or the discharge port 6a and / or the filling port 9a and / or the internal partition 7a are made of sealable fabric 1. In particular, the entire FIBC 2 is made of sealable fabric 1.

[0066] Therefore, the components of FIBC 2, namely the main fabric 7 and / or the bottom element 6 and / or the top element 9 and / or the discharge port 6a and / or the filling port 9a and / or the internal partition 7a, can be sealed or fused together at the sealing area 4, such as Figures 4-7 As shown in the image.

[0067] The two components of FIBC 2, such as the main fabric 7 and the sealable film 30 of the bottom element 6, are joined together using a heat-sealing method. To seal two sealable fabrics 1 together, the sealable films 30 of adjacent sealable fabrics 1 are placed on top of each other. Heat is then applied to the sealing area 4 to melt the sealable films 30 of the adjacent sealable fabrics 1, causing them to fuse together and form a tight and stable bond. Therefore, FIBC 2 containing a sheet of multiple sealable fabrics 1 can be manufactured without using any sewing methods, thereby enhancing the strength of FIBC 2.

[0068] List of reference numerals

[0069] 1. Sealable fabric

[0070] 2 FIBC

[0071] 4 Sealing area

[0072] 5 Openings

[0073] 6 Bottom components

[0074] 6a Discharge port

[0075] 7. Main fabric

[0076] 7a Internal partition

[0077] 8. Ring structure

[0078] 9 Top Components

[0079] 9a Filling port

[0080] 10. Woven fabrics

[0081] 11 weft yarns

[0082] 12 warp yarns

[0083] 20 Coatings

[0084] 30 Sealing film

[0085] 31 First Floor

[0086] 32 Third Floor

[0087] 33 Second Floor

Claims

1. A sealable fabric (1) for use in a flexible intermediate bulk container (FIBC) for containing bulk materials, comprising: Woven fabric containing polypropylene (10), The coating (20) contains polypropylene, and A sealable film (30) comprising sealable polypropylene, particularly sealable polypropylene resin.

2. The sealable fabric (1) according to claim 1, wherein the woven fabric (10) further comprises: Sealable polypropylene, especially sealable polypropylene resin, and / or Colorant, and / or Protective additives.

3. The sealable fabric (1) according to claim 1 or 2, wherein the woven fabric (10) has a density of 40 g / m³. 2 -300g / m 2 Especially 55 g / m 2 -250 g / m 2 75 g / m 2 -235 g / m 2 The weight.

4. The sealable fabric (1) according to any one of the preceding claims, wherein the coating (20) further comprises: Sealable polypropylene, especially sealable polypropylene resin, and / or Polyethylene, especially linear low-density polyethylene (LLDPE).

5. The sealable fabric (1) according to any one of the preceding claims, wherein the coating (20) has a density of 15 g / m². 2 -35 g / m 2 Especially 20 g / m 2 -30 g / m 2 The weight.

6. The sealable fabric (1) according to any one of the preceding claims, wherein the sealable membrane (30) further comprises: Polyethylene, particularly linear low-density polyethylene (LLDPE) and / or low-density polyethylene (LD-PE), and / or Low-flow polypropylene heterogeneous copolymers, and / or Adhesive material.

7. The sealable fabric (1) according to any one of the preceding claims, wherein the sealable film (30) comprises at least one first layer (31) and / or at least one second layer (33) and / or at least one third layer (32).

8. The sealable fabric (1) according to claim 7, wherein the first layer (31) of the sealable film (30) comprises at least 80%, preferably at least 90%, and most preferably at least 98% sealable polypropylene.

9. The sealable fabric (1) according to claim 6, 7 or 8, wherein the second layer (33) comprises polyethylene.

10. The sealable fabric (1) according to any one of claims 7-9, wherein the first layer (31) and the second layer (33) are connected to each other by a third layer (32).

11. The sealable fabric (1) according to any one of the preceding claims, wherein the sealable film (30) is a co-extruded film.

12. The sealable fabric (1) according to any one of the preceding claims, wherein the sealable film (30) is produced by a multilayer blown film method, particularly by a multilayer blown film co-extrusion method.

13. The sealable fabric (1) according to any one of the preceding claims, wherein the sealable membrane (30) has a thickness of 30 μm-160 μm, particularly 30 μm-75 μm, preferably 35 μm-45 μm.

14. A flexible intermediate bulk container (FIBC) for containing bulk materials (3, 4), comprising: At least one sheet of sealable fabric (1) according to any one of the preceding claims, which forms a leak-proof seamless usable space having at least one body fabric (7) and / or bottom element (6) and / or top element (9), preferably wherein the sealing area (4) of the sheet of at least one sealable fabric (1) is sealed together.

15. A method for manufacturing a flexible intermediate bulk container (FIBC) (3, 4) for containing bulk materials, comprising: Provide at least one sheet of sealable fabric (1) according to any of the preceding claims, wherein the FIBC is formed as follows: sealing at least one fabric (1) to form a leak-proof seamless usable space having at least one body fabric (7) and a bottom element (6), preferably wherein the sealing area (4) of the sheet of at least one sealable fabric (1) is sealed together.

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