Perforated film and filter bag

Abstract

The utility model relates to a perforated film, which is used for a filter bag and comprises a film body, and a plurality of perforations are arranged on the film body. The thickness of the film body is 15-30 [mu] m; the average pore diameter of the through holes is 200-500 microns; the aperture ratio of the through holes in the film body is below 35%; the water permeability of the perforated film is more than 1 * 10 <-3 > cm / sec; the static friction coefficient of the surface of the perforated film is 0.6 or less. The perforated film reduces product loss caused by wrinkles, bag deformation and damage due to the fact that the perforated film is clamped in the production process of the filter bag filled with leaves, stems and broken materials of the leaves, the stems and the broken materials of the leaves and the stems. The utility model further relates to a filter bag which comprises the perforated film. According to the filter bag, the filled leaves in the bag can be seen, the taste of a membrane material is avoided, and the purpose of filtering out liquid is achieved.

Description

Technical Field

[0001] The utility model relates to a perforated film and a filter bag used for loading bags for filtering extracts from black tea, green tea, dried leaves and stems of herbal plants and crushed products thereof. Background Art

[0002] The raw material of the bag for filtering the extract from the dried leaves and stems of black tea, green tea and herbal plants and their pulverized products is a material of paper or non-woven fabric or mesh.

[0003] Biodegradable paper or nonwoven or mesh materials made of biodegradable polymers are the preferred materials, but with paper or nonwoven filter bags, it is difficult to visually confirm the leaves, stems and their crushed materials in the bag, and with paper, there is also the problem of transferring the odor of the material to the extract. With mesh filter bags, there are also concerns about problems such as bag breakage and filling material falling out due to the weak joints of the bag. Utility Model Content

[0004] Based on this, it is necessary to provide a perforated film and filter bag to address the problems of current traditional technologies, which can check fillers such as leaves, stems and their crushed products, the powder of the fillers is not easy to fall off, and it is confirmed that the odor in the raw materials of the film body will not be transferred, thereby providing a delicious extract.

[0005] A perforated film for filter bags, the perforated film comprising a film body, the film body being provided with a plurality of perforations; the film body having a thickness of 15 μm to 30 μm; the average pore size of the perforations being 200 μm to 500 μm; the opening rate of the perforations in the film body being below 35%; the water permeability of the perforated film being above 1×10-3 cm / sec; and the static friction coefficient of the surface of the perforated film being below 0.6.

[0006] Furthermore, the film body is a polylactic acid film.

[0007] Furthermore, the film body is a cellulose film.

[0008] Furthermore, an adhesive layer is provided on one side of the film body.

[0009] A filter bag comprises the perforated film mentioned above.

[0010] The perforated film and filter bag of the utility model have the following beneficial effects:

[0011] The perforated film of the utility model is a material with high surface smoothness. A large number of small holes are drilled by the punching method. When the film body is opened, the residue around the small holes can be smoothed, or almost no residue is generated by the punching method, thereby reducing the product loss caused by wrinkles, bag deformation and damage caused by the jamming of the perforated film in the production process of the filter bag filled with leaves, stems and their broken materials. Moreover, the filter bag using the membrane can not only see the filled leaves in the bag, but also will not have the smell of the membrane material, so as to achieve the purpose of filtering out the liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 A schematic diagram of a perforated film according to a first embodiment of the present invention;

[0013] Figure 2 for Figure 1 Cross-sectional view of a perforated film;

[0014] Figure 3 for Figure 2 A magnified cross-sectional view of the residue produced around the holes of a perforated film;

[0015] Figure 4 A cross-sectional schematic diagram of a perforated film of the second embodiment in which the film body adopts a double-layer structure consisting of a hard-to-melt film and an adhesive layer;

[0016] Figure 5 Schematic diagram of a triangular filter bag made using the perforated film.

[0017] Numbers in the figure:

[0018] 1-Perforated film

[0019] 2-Film body

[0020] 3-Piercing

[0021] 4- Residue

[0022] 5-Difficult to melt film

[0023] 6-Joint layer

[0024] 7-Filter Bag DETAILED DESCRIPTION

[0025] In order to facilitate the understanding of the present invention, the present invention will be described in more detail below. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0027] The following is a description of the specific implementation conditions of the perforated film with reference to the accompanying drawings:

[0028] about Figure 1 , 1 is the perforated film, 2 is the film body, and 3 is the perforation.

[0029] about Figure 2 The perforation 3 is the penetration point of the perforated film 2.

[0030] about Figure 3 , 4 is the residue, the height of the residue is relatively low, indicating a smooth surface graph.

[0031] about Figure 4 , 1 is a perforated film, 5 is a heat-resistant melt film, and 6 is an adhesive layer.

[0032] Figure 5 Figure 7 is an example of a filter bag shape made of a perforated film, and Figure 7 is a schematic diagram of a triangular filter bag.

[0033] The utility model protects a perforated film 1, which includes a film body 2, and a plurality of perforations 3 are provided on the film body 2. In this embodiment, the perforated film 1 is a porous puncture film body mainly made of plant biomass; the film body 2 is a polylactic acid film body made of corn, sugar cane, potato and grain as raw materials, or a cellulose film made of wood, cotton and the like as raw materials. Among them, typical cellulose film bodies include cellophane and cellulose acetate film.

[0034] The optimal thickness of the perforated film 1 is between 15 μm and 30 μm. A thickness less than 15 μm may cause the film body to be easily damaged during the perforation and bag making process, while a thickness exceeding 30 μm may lead to deterioration of the bag making process characteristics and practical performance.

[0035] In this embodiment, the perforations 3 on the perforated film 1 preferably have an average pore size of less than 500 μm, because a large pore size will cause a large number of small filling leaves and debris to fall out. An average pore size of less than 150 μm will make the perforation process difficult, and produce a large number of defective films with poor perforations. The average pore size is preferably greater than 200 μm; that is, in this embodiment, the average pore size of the perforations 3 is preferably between 200-500 μm.

[0036] The opening ratio (also called perforation rate) of the perforation 3 should be less than 35% (the opening ratio is the ratio of the sum of the perforation areas to the total area of ​​the plate), because if the opening ratio exceeds 35%, the tensile strength of the perforated film 1 will be weakened, resulting in poor bag making processability and easy tearing and damage.

[0037] In order to avoid long filtration time, which is one of the problems of filter bags, the water permeability of the perforated film 1 (in accordance with JISA1218 standard) should be at least 1x10 -3 cm / sec, which is equivalent to or better than the water permeability of current paper tea bag base paper.

[0038] In terms of the smoothness of the surface of the extraction bag material, the static friction coefficient of the mesh material is 0.6 (in compliance with JISP8147 standard), and during the extraction bag production process, there is no product loss or downtime caused by wrinkles or bag deformation caused by the mesh material getting stuck. Therefore, the smoothness of the surface of the perforated film 1 is preferably 0.6 or less of the static friction coefficient.

[0039] As a perforation method for obtaining a highly smooth perforated film surface by reducing the height of the residue around the above-mentioned hole to a lower smooth arc surface or almost eliminating the appearance of the residue, it is recommended to use a melt perforation method in which holes are opened by irradiating energy such as heat or light, or a method using a punching needle for perforation.

[0040] like Figure 4 As shown, when the film body 2 mainly uses plant biomass film that is difficult to heat-weld, an adhesive layer 6 with polyvinylidene chloride resin (PVDC) as the main raw material is provided on one side of the film body 5 to improve the thermal adhesion of the film body during processing.

[0041] [Example 1]

[0042] A melt perforation device was used to drill 3 holes in the polylactic acid film body with a pore size of 400 μm, a porosity of 8%, and a thickness of 15 μm to produce a permeability of 3.4x10 -3 The perforated film 1 with a thickness of 100 cm / sec and a static friction coefficient of 0.34 is made into a triangular filter bag 7 by using a black tea filling machine.

[0043] [Example 2]

[0044] A melt perforation device was used to drill 3 holes in the polylactic acid film body with a pore size of 400 μm, a porosity of 8%, and a thickness of 30 μm to produce a permeability of 3.6x x10 -3 The perforated film 1 with a thickness of 100 cm / sec and a static friction coefficient of 0.34 is made into a triangular filter bag 7 by using a black tea filling machine.

[0045] Two cups of hot water were prepared, and the pyramid-shaped filter bags 7 in Example 1 and Example 2 were placed in the cups to extract black tea. It was confirmed that the triangular filter bag could maintain its shape, the black tea leaves were fully stretched in the tea bag, the aroma of the black tea was extracted, and the taste of the membrane raw material was not transferred.

[0046] Furthermore, during the production of the triangular filter bags 7 in Examples 1 and 2, there was no problem of product loss or downtime due to wrinkling of the perforated film, deformation of the bag, or rupture of the film body.

[0047] The perforated film of the utility model is a highly transparent film made of plant material as the main raw material, and the threads around the micropores are very smooth, or in other words, the microporous film is made in a way that no threads are produced. The use of this product can reduce production losses. Moreover, the filter bag using this film can not only see the filling leaves in the bag, but also does not have the smell of the film material, thereby achieving the purpose of filtering out the liquid.

[0048] The perforated film of the utility model uses a film body made of biomass mainly extracted from plants, and is a material for filter bags, which not only reduces production losses in the production process of extraction bags containing dry leaves and stems of black tea, Japanese tea, herbal plants and their crushed products. In addition, the extraction bag made using the perforated film can check fillers such as leaves, stems and their crushed products, and the powder of the fillers is not easy to fall off, and because the bag has excellent shape maintenance performance, the tea leaves can be fully stretched in cold water or hot water, the stretching state of the leaves can be checked, and it can be confirmed that the smell in the raw material of the film body will not be transferred, thereby providing a delicious extract.

[0049] The above-mentioned embodiments only express several implementation methods of the utility model, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the utility model. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the utility model, and these all belong to the protection scope of the utility model. Therefore, the protection scope of the utility model patent shall be based on the attached claims.

Claims

1. A perforated film for a filter bag, characterized in that: The perforated film comprises a film body, on which a plurality of perforations are arranged; the thickness of the film body is 15 μm to 30 μm; the average pore size of the perforations is 200 μm to 500 μm; the opening rate of the perforations in the film body is less than 35%; the water permeability of the perforated film is 1x10 -3 cm / sec or above; the static friction coefficient of the surface of the perforated film is below 0.

6.

2. The perforated film according to claim 1, characterized in that The film body is a polylactic acid film.

3. The perforated film according to claim 1, characterized in that The film body is a cellulose film.

4. The perforated film according to claim 1, characterized in that An adhesive layer is provided on one side of the film body.

5. A filter bag, characterized in that: The invention comprises a perforated film as claimed in any one of claims 1 to 4.

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