A production process of vacuum bag film, vacuum bag film and water-locking vacuum bag

Abstract

The present invention discloses a production process for a vacuum bag film, comprising the following steps: S1: preheating and softening a film; S2: rolling the softened film obtained in S1 with a pair of rollers consisting of a roller and a rubber roller, wherein the roller surface is provided with dotted protrusions, and rolling the first surface of the film with the roller to form a water-locking depression and a convex ring on the first surface, with the convex ring located at the outer edge of the opening of the water-locking depression; S3: cooling the film; the preheating temperature of S1 is not less than the softening temperature of the film. The production process for the vacuum bag film first preheats and softens the film, and then rolls the softened film with the dotted protrusions provided on the roller surface and the pair of rollers consisting of a rubber roller to form a first surface having a water-locking depression and a convex ring located at the outer edge of the opening of the water-locking depression; the first surface of the vacuum bag film having the dotted water-locking depression and the convex ring effectively prevents excessive extraction of water from the bag when the vacuum bag is evacuated, thereby retaining a large amount of water in the vacuum bag. The present invention also discloses a vacuum bag film rolled by the above method and a water-locking vacuum bag made from the above vacuum bag film.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic packaging bag films, in particular to a production process of vacuum bag films, vacuum bag films and water-locking vacuum bags. Background Art

[0002] Vacuum bags, also known as decompression packaging, are made by evacuating the air in the packaging container into a low vacuum and then sealing it. Since there is very little residual air in the bag, the growth of microorganisms such as bacteria is inhibited, effectively preventing the oxidation, mildew and corruption of the items, thus achieving the purpose of keeping the items fresh.

[0003] At present, ordinary vacuum bags are more commonly used in the market. Both layers are smooth and have no moisture-locking function. During the vacuuming process, it is very easy for the upper and lower layers to stick together and form wrinkles, resulting in poor exhaust and a lot of residual air in the bag, which not only affects the appearance of the packaging, but also has a poor preservation effect.

[0004] In the prior art, patent publication number CN207450699U discloses a new type of vacuum bag, comprising a bag body with an open end, the bag body comprising a first bag surface and a second bag surface arranged opposite to each other, an opening provided at one end of the first bag surface and the second bag surface, the inner surface of the first bag surface and / or the second bag surface being provided with an air guide structure for guiding the air in the accommodating cavity to be evacuated, the air guide structure comprising at least one layer of film provided on the inner surface of the first bag surface and / or the second bag surface, the film being provided with a plurality of micropores.

[0005] The defect in the existing technology is that the above-mentioned air guide structure only has the function of guiding air. While guiding air, it is easy to extract moisture from the vacuum package, but cannot preserve more moisture in the vacuum package, which is not conducive to locking moisture and preserving the liquid packaged objects. Summary of the Invention

[0006] One of the purposes of the present invention is to overcome the defects in the prior art and provide a production process for vacuum bag film.

[0007] In order to achieve the above technical effects, the technical solution of the present invention is: a production process for vacuum bag film, comprising the following steps: S1: preheating and softening the film; S2: rolling the softened film obtained by S1 with a pair of rollers consisting of a roller and a rubber roller, the surface of the roller being provided with dotted protrusions, and the roller rolling the first surface of the film to form a water-locking depression and a convex ring on the first surface, and the convex ring being located at the outer edge of the opening of the water-locking depression; S3: cooling the film; the preheating temperature of S1 is not less than the softening temperature of the film.

[0008] The roller speed is 45-50m / min. The film softening heating method is electric heating oil heat conduction.

[0009] A preferred technical solution is: the film is an inner layer film, further comprising: S4: laminating the surface film to the second surface of the inner layer film. The inner layer film has a thickness of 20 to 35 μm. The bonding strength between the surface film and the second surface of the inner layer film is greater than 5N.

[0010] In order to prevent the softened film surface from deforming due to shrinkage during cooling, a preferred technical solution is: the cooling temperature is 0-15° C. Further, the cooling temperature is 0-10° C. The cooling method is a cooling roller.

[0011] The inner film is made of a polyolefin material that is easily processed into a water-locking depression. To ensure that the water-locking depression and the convex ring are formed by rolling, a preferred technical solution is: the temperature difference between the preheating temperature of S1 and the softening temperature of the film is 0-10°C. Furthermore, the temperature difference between the preheating temperature of S1 and the softening temperature of the film is 0-5°C. Furthermore, the polyolefin is polyethylene. Even more preferably, the polyethylene is low-density polyethylene (LDPE).

[0012] A preferred technical solution is: the water-locking depressions are through-holes in the inner film, and the ratio of the roller protrusion height to the film thickness is (1.5-2.5):1. The water-locking depressions can be through-holes in the inner film or blind holes on the first surface of the inner film. As the dot-shaped protrusions on the roller pierce the softened film and pull it up, naturally cooling and shrinking in contact with ambient temperature, the inner film forms an expanded through-hole and a raised ring at the outer edge of the through-hole opening.

[0013] The film thickness, distribution density and size of the water-locking depressions must meet the formation of the water-locking depressions and the air-guiding network. In order to achieve the best water-locking effect, the preferred technical solution is: the number of the dot-shaped protrusions is 1.6 to 2 million per m 2 .

[0014] Compared to a circle of the same area, a hexagon has a larger perimeter. With the same density of water-locking depressions on the surface of the vacuum bag film, the hexagonal structure forms a more divergent air-guiding network. To optimize the structure of the water-locking depressions and form a network of air-guiding protrusions, the preferred technical solution is: the dot-shaped protrusions are selected from frustums or cones with a hexagonal base. The hexagonal base can be an irregular hexagon, a regular hexagon, or an axisymmetric hexagon other than a regular hexagon.

[0015] The second purpose of the present invention is to overcome the defects existing in the prior art and provide a vacuum bag film, the surface of which is provided with a dotted water-locking depression, the outer edge of the opening of the water-locking depression is provided with a convex ring, and the intervals between the convex rings are combined into a mesh-shaped air guide channel.

[0016] The structure of the water-locking concave is any geometric shape. Further, the structure of the water-locking concave is a hexagon.

[0017] To ensure that the water-locking depressions retain more moisture while simultaneously achieving optimal air-blocking effects, a preferred technical solution is as follows: the vacuum bagging film comprises a surface film and an inner film. The water-locking depressions are through-holes in the inner film, with one end opening being a first opening and the other end opening being a second opening, the second opening facing the surface film; the first opening is smaller than the second opening. During vacuuming, the external pressure becomes greater than the pressure inside the bag. Due to this pressure differential, the amount of gas in the second opening decreases while the amount of liquid increases, creating a liquid seal that isolates the gas from the food. To prevent external water and gas from entering the vacuum packaging and affecting the food's quality and freshness, the surface film is further configured as a barrier film. The barrier film can be a single layer or a composite film, including a film containing a barrier material, and the composite film is produced by coextrusion or hot pressing. To balance the barrier properties and processability of the vacuum bagging film, the surface film is further configured as nylon and the inner film as polyethylene.

[0018] The third object of the present invention is to provide a water-locking vacuum bag, comprising a first bag surface, wherein the first bag surface is the above-mentioned vacuum bag film, and the surface of the vacuum bag film provided with the water-locking recess is the inner surface of the first bag surface.

[0019] The bag body can be in a common geometric or special shape, such as a rectangle or circle. It can also be a side-folded bag, such as the structure described in CN207450699U. The bag body can be a double-sided bag or a multi-sided bag. The other bag surfaces besides the first bag surface can also be vacuum bagging film.

[0020] The advantages and beneficial effects of the present invention are:

[0021] 1. The production process of the vacuum bag film is to preheat and soften the film first, and then pass the dot-shaped protrusions provided on the roller surface and the roller consisting of a rubber roller to press the softened film to obtain a first surface with a water-locking depression and a protruding ring located at the outer edge of the opening of the water-locking depression;

[0022] 2. The first surface of the obtained vacuum bag film has dot-shaped water-locking depressions and convex rings, which effectively prevent excessive water from being extracted from the bag when the vacuum bag is evacuated, thereby retaining more water in the vacuum bag. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a partial enlarged view of the first surface of the vacuum bag film embodiment 1 of the present invention;

[0024] Figure 2 yes Figure 1 Cross-sectional view along AA;

[0025] Figure 3 This is a partial enlarged view of the first surface of the vacuum bag film embodiment 2 of the present invention;

[0026] Figure 4 yes Figure 3 Cross-sectional view along AA;

[0027] Figure 5 2. It is a schematic structural diagram of a cross section of a vacuum bag film embodiment 3 of the present invention;

[0028] Figure 6 This is a schematic structural diagram of a cross section of a fourth embodiment of the vacuum bag film of the present invention;

[0029] Figure 7 This is a schematic structural diagram of Example 5 of a water-locking vacuum bag of the present invention;

[0030] Figure 8 It is a structural schematic diagram of the cross section of Example 6 of the water-locking vacuum bag of the present invention.

[0031] In the figure, 1, vacuum bag film; 1-A, first bag surface; 1-B, second bag surface; 2, water-locking depression; 2-A, blind hole; 2-B, through hole; 3, air guide channel; 10, surface film; 11, inner film; 110, first inner film; 111, second inner film; 21, convex ring; 201, first orifice; 202, second orifice. DETAILED DESCRIPTION

[0032] The following examples are only used to illustrate the technical solutions of the present invention more clearly, and are not intended to limit the scope of protection of the present invention.

[0033] Example 1

[0034] The production process of vacuum bag film includes the following steps:

[0035] S1: preheating to soften the film;

[0036] S2: A pair of rollers consisting of a roller and a rubber roller rolls the softened film obtained in S1. The surface of the roller is provided with dotted protrusions. The roller rolls the first surface of the film to form a water-locking depression and a protruding ring on the first surface. The protruding ring is located at the outer edge of the opening of the water-locking depression.

[0037] S3: Cooling the film.

[0038] The temperature difference between the preheating temperature of S1 and the softening temperature of the film is 5°C. The film softening heating method is electric heating oil heat conduction.

[0039] The cooling temperature is 5°C, and the cooling method is to use a cooling roller to quench the rolled film.

[0040] The roller speed is 45m / min.

[0041] The layer thickness of the film was 35 μm.

[0042] The bottom surface of the dot-shaped protrusions on the roller is in the shape of a square frustum.

[0043] like Figures 1-2 As shown, the surface of the vacuum bag film 1 of Example 1 is provided with dot-shaped water-locking depressions 2, the outer edge of the opening of the water-locking depression 2 is provided with a convex ring 21, and the intervals between the convex rings 21 are combined into a mesh-shaped air guide channel 3.

[0044] The water-locking depressions 2 are square and arranged side by side along the row direction, and the water-locking depressions 2 of two adjacent rows are staggered. The number of water-locking depressions 2 is 1.8 million / m 2 .

[0045] Example 2

[0046] Example 2 is based on the vacuum bag film of Example 1, except that the film is the inner layer film, and further comprises: S4: compounding the surface layer film with the second surface of the inner layer film.

[0047] The surface layer film 10 is made of nylon, and the inner layer film 11 is made of LDPE.

[0048] The inner film has a thickness of 28 μm. The second surface bonding strength between the surface film and the inner film is greater than 5 N. The adhesive between the surface film and the inner film is LLDPE grafted with maleic anhydride, brand Basel PX3060.

[0049] The bottom surface of the dot-shaped protrusions on the roller is in the shape of a hexagonal frustum.

[0050] like Figures 3-4 As shown, the vacuum bag film 1 includes a surface film 10 and an inner film 11, and the water-locking recess 2 is a blind hole 2-A on the inner surface of the inner film 11; the blind hole 2-A has a hexagonal structure.

[0051] Example 3

[0052] Example 3 is based on the vacuum bag film of Example 2, except that the ratio of the roller protrusion height to the film thickness is 2:1.

[0053] like Figure 5 As shown, the water-locking recess 2 is a through hole 2-B on the inner film 11; the through hole 2-B is a hexagonal structure; the opening at one end of the through hole 2-B is a first opening 201, and the opening at the other end is a second opening 202, and the second opening 202 faces the surface film 10; the first opening 201 is smaller than the second opening 202.

[0054] Example 4

[0055] like Figure 6As shown, Example 4 is based on the vacuum bag film of Example 2, with the difference that the inner film 11 includes a first inner film 110 and a second inner film 111, the second inner film 111 is sandwiched between the surface film 10 and the first inner film 110, the water-locking recess 2 is a combination of the through hole 2-B on the first inner film 110 and the blind hole 2-A on the inner surface of the second inner film 111, and the through hole 2-B on the first inner film 110 is a hexagonal structure; the size of the through hole 2-B on the first inner film 110 is smaller than the size of the blind hole 2-A on the inner surface of the second inner film 111.

[0056] The first inner layer film 110 and the second inner layer film 111 are both made of LDPE. The first inner layer film 110 and the second inner layer film 111 are laminated by hot pressing, and the surface film 10 and the inner layer film 11 are laminated by hot melting.

[0057] The blind holes 2 -A on the inner surface of the second inner layer film 111 can be equivalently replaced by through holes 2 -B.

[0058] Example 5

[0059] like Figure 7 As shown, the water-locking vacuum bag is rectangular and includes a first bag surface 1-A and a second bag surface 1-B. The first bag surface 1-A and the second bag surface 1-B are heat-sealed on three sides to form a storage cavity and an opening. The first bag surface 1-A is the vacuum bag film of Example 3, and the surface of the vacuum bag film with the water-locking recess 2 is the inner surface of the first bag surface 1-A.

[0060] Example 6

[0061] like Figure 8 As shown, Example 6 is based on Example 5, with the difference that the first bag surface 1-A and the second bag surface 1-B of the water-locking vacuum bag are both the vacuum bag films of Example 2, and the surfaces of the vacuum bag film having the water-locking recess 2 are the inner surfaces of the first bag surface 1-A and the second bag surface 1-B respectively.

[0062] When using the water-locking vacuum bag of Example 5, open the bag mouth and put the packaged object into the storage cavity. The first hole 201 of the through hole 2-B on the inner surface of the inner film 11 is facing the packaged object. When vacuuming, the gas in the bag is quickly extracted along the air guide channel 3. The external pressure is greater than the pressure inside the bag. Due to the effect of the pressure difference, the gas compression amount in the second hole is reduced, while the amount of liquid in the second hole is increased, forming a liquid seal to isolate the gas from contact with food. Therefore, the water-locking depression 2 realizes the water-locking function.

[0063] When using the water-locking vacuum bag of Example 6, the bag mouth is opened and the packaged object is placed in the storage cavity, with the blind hole 2-A on the inner surface of the inner film 11 facing the packaged object. When air is evacuated, the liquid in the bag fills the blind hole 2-A, and most of the gas in the blind hole 2-A is replaced by water, thereby isolating the gas from contacting the food, and the water-locking depression 2 realizes the water-locking function.

[0064] A small household food vacuum machine was used to conduct a vacuum test on the packaging bag of Example 5. The voltage of the small household food vacuum machine was 100-110V. The specification of the packaging bag was 20×25cm×16 wire, and the weight of 100 grams was 800g. The packaged content was fresh fish. The packaging bag of Example 5 of the present invention completed vacuuming within 20 seconds, and the bag mouth was automatically heat-sealed with a heat-sealing pressure of 2.5MPa. However, ordinary vacuum bags with both layers of smooth surface on the market failed to complete the air extraction in more than 2 minutes, and the heat sealing effect was poor, and the bag mouth was often not heat-sealed tightly. The packaging bag of Example 5 after vacuuming and bag mouth heat sealing was placed under a microscope, and it was observed that there was moisture in the water-locking depression on the inner surface of the first bag surface.

[0065] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as within the scope of protection of the present invention.

Claims

1. A production process for vacuum bag film, characterized in that: The following steps are involved: S1: preheating to soften the film; S2: A pair of rollers consisting of a roller and a rubber roller rolls the softened film obtained in S1, wherein the surface of the roller is provided with dotted protrusions. The roller rolls the first surface of the film to form a water-locking depression and a convex ring on the first surface, wherein the convex ring is located at the outer edge of the opening of the water-locking depression; S3: cooling film; The preheating temperature of S1 is not less than the softening temperature of the film.

2. The production process of vacuum bag film according to claim 1, characterized in that: The film is an inner layer film, and further comprises: S4: Compounding the surface layer film with the second surface of the inner layer film.

3. The production process of vacuum bag film according to claim 1, characterized in that: The cooling temperature is 0-15°C.

4. The production process of vacuum bag film according to claim 1, characterized in that: The temperature difference between the preheating temperature of S1 and the softening temperature of the film is 0-10°C.

5. The production process of vacuum bag film according to claim 2, characterized in that: The water-locking depression is a through hole on the inner layer film, and the ratio of the roller protrusion height to the film thickness is (1.5~2.5):

1.

6. The production process of vacuum bag film according to claim 1, characterized in that: The number of the dot-shaped protrusions is 1.6 to 2 million per m 2 .

7. The production process of vacuum bag film according to claim 1, characterized in that: The point-shaped protrusions are selected from a truncated cone or a cone with a hexagonal bottom surface.

8. A vacuum bag film, characterized in that: Based on the production process of the vacuum bag film according to any one of claims 1 to 7, the surface of the vacuum bag film is provided with dotted water-locking depressions, the outer edge of the opening of the water-locking depression is provided with a convex ring, and the intervals between the convex rings are combined into a mesh-shaped air guide channel.

9. The vacuum bag film according to claim 8, characterized in that The vacuum bag film includes a surface film and an inner film, the water-locking depression is a through hole on the inner film, one end opening of the through hole is a first opening, and the other end opening is a second opening, the second opening faces the surface film; the first opening is smaller than the second opening.

10. A water-locking vacuum bag, comprising a first bag surface, characterized in that: The first bag surface is the vacuum bag film according to any one of claims 8 to 9, and the surface of the vacuum bag film provided with the water-locking recess is the inner surface of the first bag surface.

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