A multi-strip block alternately transparent anti-fog antibacterial film bag and a preparation method thereof

Abstract

The application discloses a multi-strip alternately transparent anti-fog and antibacterial film bag and a preparation method thereof. The alternately transparent film bag is a single-layer structure or a double-layer structure or a three-layer structure. The inner layer of the single-layer or double-layer structure or the middle layer or the inner layer of the three-layer structure is provided with a plurality of first anti-fog strip blocks and a plurality of second anti-fog strip blocks which are different from the first anti-fog strip blocks in anti-fog time efficiency. The first anti-fog strip blocks and the second anti-fog strip blocks are alternately arranged. One anti-fog strip block comprises the following components in weight ratio: a plastic carrier 21-41, inorganic powder 30-38, an antioxidant 0.2-0.5, an antibacterial preservative 2-4, a modifier 0.8-1.2, a dispersing agent 2.8-3.5, an opening agent 1.2-1.6 and an anti-fog agent 22-30.2. The application solves the problem that polyolefin cannot be converted into products due to the increase of the anti-fog agent adding amount and the influence of inorganic powder on transparency in the early stage.

Description

TECHNICAL FIELD

[0001] The present application relates to a packaging film bag, in particular to a multi-strip block alternating transparent anti-fog antibacterial film bag and a preparation method thereof. BACKGROUND

[0002] At present, while people increasingly pursue the use of high-transparency fruit and vegetable anti-fog preservation film bags, the anti-fog packaging industry is facing severe challenges, because the film bag will be affected in transparency to some extent as long as anti-fog additives are added. Obviously, the early transparency of the film bag will be more affected if high-content anti-fog master batches with inorganic powder release agents are added. The present situation is that either low-content early high-transparency anti-fog master batches are selected, or high-content anti-fog antibacterial master batches with general early transparency and high transparency in the middle and later stages are selected. Ultimately, in reality, low-content anti-fog master batches are almost selected for high-transparency film bags on the market, and the anti-fog amount is limited to only meet the high-transparency requirement for a short period of time. Therefore, the existing high-pressure PE high-content anti-fog master batch is difficult to promote, and there is no polyolefin, especially low-pressure PE special low-pressure PE high-content anti-fog antibacterial master batch, or even no polyolefin, especially low-pressure PE special conventional content anti-fog antibacterial master batch. As a result, the existing anti-fog film bag, especially the low-pressure PE anti-fog film bag with the largest amount, has a short anti-fog time and poor preservation ability. It is urgent to develop a new anti-fog antibacterial film bag that can provide long-term anti-fog high-transparency and long-term antibacterial preservation. SUMMARY

[0003] The present application aims to solve the problem that the film bag cannot achieve longer anti-fog time and longer high-transparency period, and in particular to solve the problem that the existing high-pressure PE high-content anti-fog master batch is difficult to promote due to its general initial transparency, and the low-pressure PE film bag has no low-pressure PE high-content anti-fog antibacterial master batch support.

[0004] The present application overcomes the deficiencies of the prior art and provides a new high-content anti-fog antibacterial master batch, which fully utilizes and takes advantage of the respective advantages of the low-pressure PE high-content anti-fog antibacterial master batch a and the initial transparent low-pressure PE ordinary content anti-fog antibacterial master batch b provided by the present application. The two anti-fog effect different film blocks are arranged in a vertical strip block parallel staggered co-extrusion connection structure, so as to realize a multi-strip block alternating transparent anti-fog antibacterial film bag and a preparation method thereof, which can utilize the complementary long and short time effects of different strips and blocks and realize the alternating transparency of the front and back.

[0005] To achieve the above-mentioned purposes, the present application adopts the following technical solutions:

[0006] The application discloses a multi-strip alternately transparent anti-fog and antibacterial film bag, which is a single-layer structure, a double-layer structure of an inner layer and an outer layer, or a three-layer structure including an inner layer, a middle layer and an outer layer, characterized in that the single-layer structure, the inner layer of the double-layer structure or the inner layer or the middle layer of the three-layer structure includes a plurality of first anti-fog strips and a plurality of second anti-fog strips with different anti-fog time efficiency from the first anti-fog strips, wherein the first anti-fog strips and the second anti-fog strips are alternately arranged, the outer layer of the double-layer structure is a transparent film layer without adding anti-fog master batch, the inner layer and the outer layer of the three-layer structure are transparent layers with adding common content anti-fog master batch b, and the strip connection seam area of the single-layer structure is locally provided with an outwardly protruding thickening section along the inner side; the double-layer or three-layer structure is locally provided with or not provided with an outwardly protruding thickening section along the outer side of the inner layer at the strip connection seam area of the inner layer or the middle layer.

[0007] The first anti-fog strip is prepared by adding 8.0-10% of the polyolefin high-pressure or low-pressure PE high-content anti-fog and antibacterial master batch a, belongs to long-acting anti-fog and antibacterial, and is a high-transparency strip in the middle and later periods. The master batch a includes the following components in parts by weight: 21-41 of a plastic carrier, 30-38 of inorganic powder, 0.2-0.5 of an antioxidant, 2.0-4.0 of an antibacterial preservative, 0.8-1.2 of a modifier, 2.8-3.5 of a dispersant, 1.2-1.6 of an opening agent and 22-30.2 of an anti-fog agent. The inorganic powder is a compound of at least one of precipitated barium sulfate, white carbon black, talcum powder, hydrotalcite and diatomite powder and white carbon black, and the compound ratio is 1:2-1:3 of the total amount of at least one of precipitated barium sulfate, talcum powder, hydrotalcite and diatomite powder to the total amount of white carbon black. In preparation, the plastic carrier, the inorganic powder, the antioxidant and the antibacterial preservative are respectively metered and put into a stirring machine barrel, stirred until the moisture of the material is lower than 1%, then the modifier and the dispersant are put in for surface coating treatment, and finally the opening agent and the anti-fog agent are put in for mixing treatment. After the above materials are fully stirred by the stirring machine, they are melted, plasticized and extruded by a double-screw granulator, and finally cooled and granulated into the master batch a product.

[0008] The second anti-fog strip is a short-acting anti-fog, initial high-transparency and antibacterial strip, and is prepared by adding 6-8% of a polyolefin low-pressure PE common-content anti-fog and antibacterial master batch b. The master batch b includes the following components in parts by weight: 72-79.5 of a plastic carrier, 0.2-0.5 of an antioxidant, 3.0-5.5 of an antibacterial preservative, 0.6-1.0 of a dispersant, 0.7-1.0 of an opening agent and 16-20 of an anti-fog agent. The plastic carrier, the antioxidant, the antibacterial preservative, the dispersant, the opening agent and the anti-fog agent are simultaneously metered and put into a stirring machine for mixing treatment, the mixing time is 1-3 min, then the anti-fog agent is put in for mixing treatment for 1-3 min, and finally the above materials are fully and uniformly mixed by the stirring machine, melted, plasticized and extruded by a double-screw granulator, and cooled and granulated into the master batch b product.

[0009] The cooling includes air cooling or water cooling granulation.

[0010] Preferably, the long-acting anti-fogging antibacterial middle and late transparent strip (first strip) includes low-pressure HDPE 68-81%, high-pressure LDPE 5-10%, toughening agent 6-12%, and master batch a prepared in step one A 8-10%.

[0011] Preferably, the initial transparent but low-antifogging agent content and short-acting strip (second strip) includes low-pressure HDPE 65-78%, high-pressure LDPE 10-15%, toughening agent 6-12%, and master batch b prepared in step one B 6-8%.

[0012] The application can also be used in high-pressure PE film bags, wherein the high-pressure PE film bags are made by adding the long-acting middle and late transparent strip and the short-acting initial transparent strip with the master batch a and the master batch b of the application, respectively.

[0013] In a preferred embodiment of the application, the plastic carrier is a compound of two or more of LDPE (low-density polyethylene), LLDPE (linear low-density polyethylene), EVA (ethylene-vinyl acetate copolymer), and APP (random polypropylene).

[0014] In a preferred embodiment of the application, the antifogging agent is a compound of two or more of Tween, monoglyceride, polyoxyethylene ether, stearic acid diethanolamine, and polyglycerol fatty acid ester, and polyglycerol oleate.

[0015] In a preferred embodiment of the application, the modifier can be one of silane coupling agent, titanate coupling agent, and aluminate coupling agent.

[0016] In a preferred embodiment of the application, the dispersant can be at least one of stearic acid or polyethylene wax.

[0017] In a preferred embodiment of the application, the opening agent can be one or both of erucic acid amide and oleic acid amide.

[0018] In a preferred embodiment of the application, the antioxidant can be at least one of antioxidant 1010, antioxidant 168, and antioxidant B215.

[0019] In a preferred embodiment of the application, the antibacterial preservative is at least one of D-sodium erythorbate, potassium sorbate, sodium benzoate, sodium dehydroacetate, and silver ion, or a compound of two or more thereof.

[0020] Preferably, the thickness of the outer layer of the double-layer structure is 1 / 2 to 2 / 2 of the thickness of the inner layer, and the thickness of the outer convex thickening section of the thickening section of the outer layer accounts for 10-50% of the thickness of the non-thickening section of the outer layer.

[0021] Preferably, when the three-layer structure is ABC structure, the outer convex thickening of the outer thickened section accounts for 10-50% of the thickness of the non-thickened section of the outer layer; when the three-layer structure is ABA structure, the middle layer comprises a plurality of first anti-fog strips and a plurality of second anti-fog strips with different anti-fog time efficiency than the first anti-fog strips, wherein the first anti-fog strips and the second anti-fog strips are arranged alternately, and the outer convex thickening of the outer thickened section accounts for 10-200% of the thickness of the non-thickened section of the outer layer.

[0022] Preferably, the outer convex thickened section of the double-layer or three-layer structure extends 5.0-40 mm on both sides of the center line of the joint between the first anti-fog strip and the second anti-fog strip.

[0023] Preferably, the film bag is single-layer, and the thickness of the thickened part of the outer convex thickened section accounts for 10%-50% of the thickness of the non-thickened area of the first anti-fog strip or the second anti-fog strip; the length of the thickened section extends 5.0-40 mm on both sides of the center line of the joint between the first anti-fog strip and the second anti-fog strip.

[0024] Still another technical solution of the present application is:

[0025] A multi-strip alternately transparent anti-fog and antibacterial film bag, which is single-layer structure, or double-layer structure with an inner layer and an outer layer, or three-layer structure comprising an inner layer, a middle layer and an outer layer, characterized in that: the single-layer structure, or the inner layer of the double-layer structure, or the inner layer or the middle layer of the three-layer structure comprises a plurality of first anti-fog strips and a plurality of second anti-fog strips with different anti-fog time efficiency than the first anti-fog strips, wherein the first anti-fog strips and the second anti-fog strips are arranged alternately, the outer layer of the double-layer structure is a high-transparency film layer without adding anti-fog master batch, the inner layer and the outer layer of the three-layer structure are high-transparency layers with ordinary content of anti-fog master batch b when the three-layer structure is ABA structure, or the outer layer of the three-layer structure is a high-transparency film layer without adding anti-fog master batch, and the middle layer is a transparent layer which can or can not add anti-fog master batch when the three-layer structure is ABC structure, and a lap joint area is provided between all the first strips and the second strips, that is, the first strips and the second strips respectively extend a lap tongue, and the two lap tongues are lap-jointed inwardly and outwardly; at the outer edge of the inner layer corresponding to the lap joint, the three-layer structure of ABA has no lap joint outer convex reinforcing section or no outer convex reinforcing section covering the lap joint, and the three-layer structure of ABC has an outer convex lap joint reinforcing section covering the lap joint or no outer convex lap joint reinforcing section;

[0026] wherein the first anti-fog strips add 8.0-10% of polyolefin high-pressure or low-pressure PE high-content anti-fog and antibacterial master batch a; the second anti-fog strips add 8.0-10% of polyolefin high-pressure or low-pressure PE high-content anti-fog and antibacterial master batch b; and the middle layer of the three-layer structure adds 0-10% of polyolefin high-pressure or low-pressure PE high-content anti-fog and antibacterial master batch c.

[0027] The master batch a is prepared by mixing the following components in parts by weight: plastic carrier 21-41, inorganic powder 30-38, antioxidant 0.2-0.5, antibacterial preservative 2.0-4.0, modifier 0.8-1.2, dispersant 2.8-3.5, opening agent 1.2-1.6, and anti-fogging agent 22-30.2. The inorganic powder is a mixture of at least one of precipitated barium sulfate, white carbon black, talc powder, hydrotalcite, and diatomite powder and white carbon black, and the ratio of the total amount of at least one of precipitated barium sulfate, talc powder, hydrotalcite, and diatomite powder to the total amount of white carbon black is 1:2-1:3. During preparation, the plastic carrier, inorganic powder, antioxidant, and antibacterial preservative are measured and put into a stirring machine barrel, and stirred until the material dryness is less than 1%. Then the modifier and dispersant are put in for surface coating treatment. Finally, the opening agent and anti-fogging agent are put in, stirred uniformly, and then melted, plasticized, and extruded by a double-screw granulator, and finally cooled and granulated to obtain the master batch a product.

[0028] The second anti-fogging strip block is added with 6-8% polyolefin high-pressure or low-pressure PE ordinary content anti-fogging and antibacterial master batch b. The master batch b is prepared by mixing the following components in parts by weight: plastic carrier 72-79.5, antioxidant 0.2-0.5, antibacterial preservative 3.0-5.5, dispersant 0.6-1.0, opening agent 0.7-1.0, and anti-fogging agent 16-20. During preparation, the plastic carrier, antioxidant, antibacterial preservative, dispersant, and opening agent are measured and put into a stirring machine at the same time for mixing treatment for 1-3 min, and then the anti-fogging agent is put in for mixing treatment for 1-3 min. The material is fully and uniformly mixed by a stirring machine, and then melted, plasticized, and extruded by a double-screw granulator, and finally cooled and granulated to obtain the master batch b product.

[0029] In the preferred embodiment, in the single-layer structure, the outer convex lap thickening section is arranged on the inner and outer edges, or only on the inner edge, and the outer convex lap thickening accounts for 10-50% of the thickness of the non-thickening section of the layer; the thickness of the outer layer of the double-layer structure is 1 / 2 to 2 / 2 of the thickness of the inner layer, the outer convex lap thickening section of the inner layer accounts for 10-50% of the thickness of the non-thickening section of the inner layer, or no outer convex lap thickening section is arranged; when the three-layer structure is in the ABC structure, no outer convex lap thickening section is arranged, or only the outer convex lap thickening section of the inner layer is arranged, and the outer convex lap thickening accounts for 10-50% of the thickness of the non-thickening section of the inner layer; when the three-layer structure is in the ABA structure, the outer convex lap thickening section of the inner layer accounts for 10-200% of the thickness of the non-thickening section of the inner layer, or no outer convex lap thickening section is arranged.

[0030] In the preferred embodiment, the length of the outer convex lap thickening section of the inner layer extends 5.0-40 mm on both sides of the center line of the joint between the first anti-fogging strip block and the second anti-fogging strip block.

[0031] The present application also provides a co-extrusion die head for preparing the multi-strip block alternating transparent anti-fog and antibacterial film bag, which has a circular groove, and the groove comprises a single-layer groove with a single-layer flow channel, a double-layer flow channel groove with an inner layer and an outer layer, or a three-layer flow channel groove with an inner layer, an outer layer and a middle layer.

[0032] Another technical solution of the present application is a preparation method of the multi-strip block alternating transparent anti-fog and antibacterial film bag, which comprises the following steps:

[0033] Step one. Preparation of master batch

[0034] A. Preparation of high-content anti-fog and antibacterial master batch for polyolefin high-pressure or low-pressure PE (master batch a)

[0035] (1) First, 21-41 plastic carriers, 30-38 inorganic powders, 0.2-0.5 antioxidants, and 2-4 antibacterial preservatives are weighed and put into the stirring barrel, and stirred until the moisture content of the material is less than 1%;

[0036] (2) 0.8-1.2 modifiers and 2.8-3.5 dispersants are put in for surface coating treatment;

[0037] (3) 1.2-1.6 opening agents and 22-30.2 anti-fogging agents are put in for uniform mixing treatment;

[0038] (4) The above treated mixture is melted, plasticized, and extruded through a double-screw granulator, and finally cooled and granulated into master batch a finished product;

[0039] B. Preparation of ordinary content anti-fog and antibacterial master batch for polyolefin low-pressure PE (master batch b):

[0040] According to the weight ratio, it comprises 72-79.5 plastic carriers, 0.2-0.5 antioxidants, 3.0-5.5 antibacterial preservatives, 0.6-1.0 dispersants, 0.7-1.0 opening agents, and 16-20 anti-fogging agents. First, the plastic carrier, antioxidant, antibacterial preservative, dispersant, opening agent are weighed and put into the stirrer for mixing treatment, the mixing time is 1-3 min, then the anti-fogging agent is put in for mixing treatment for 1-3 min. After the above materials are fully and uniformly mixed by the stirrer, they are melted, plasticized and extruded through a double-screw granulator, and finally cooled and granulated to obtain master batch b finished product.

[0041] Step two. Preparation of alternating transparent film bag

[0042] Preparation of low-pressure PE anti-fog antibacterial alternating transparent film bag:

[0043] (1). Preparation of the first anti-fog strip block, which contains components: low-pressure HDPE 65-78%, high-pressure LDPE 10-15%, toughening agent 6-12%, master batch b prepared in step one B 6-8%;

[0044] (2). Preparation of the second anti-fog strip block, which contains components: low-pressure HDPE 68-81%, high-pressure LDPE 5-10%, toughening agent 6-12%, master batch a prepared in step one A 8-10%;

[0045] Preparation of high-pressure PE anti-fog antibacterial alternating transparent film bag:

[0046] (1) Preparation of the first anti-fog strip block, which contains components: linear high-pressure LLDPE 66-79%, high-pressure LDPE 10-15%, toughening agent 5-10%, opening master batch 2-3%, master batch b prepared in step one B 4-6%;

[0047] (2) Preparation of the second anti-fog strip block, which contains components: linear high-pressure LLDPE 64-77%, high-pressure LDPE 10-15%, toughening agent 5-10%, opening master batch 2-3%, master batch a prepared in step one A 6-8%;

[0048] The A (preparation of low-pressure PE anti-fog antibacterial alternating transparent film bag) and B (preparation of high-pressure PE anti-fog antibacterial alternating transparent film bag) in the above step two are blown into film bags by co-extrusion.

[0049] In a preferred embodiment of the preparation of master batch a in the present application, the temperature of each section of the extruder of the twin-screw granulator is determined according to the actual melting and plasticizing temperature of the mixture; the temperature of the melting and plasticizing section (1-2 zone) is 160-170℃; the temperature of the melting and plasticizing section (3-6 zone) is 145-155℃; the temperature of the melting and plasticizing over section (7 zone) is 135-140℃; the temperature of the plasticizing and cooling section (8-9 zone) is 100-120℃; the temperature of the plasticizing and cooling section (10-11 zone) is 90-100℃; and the temperature of the die (12 zone) is 85-95℃.

[0050] In another preferred embodiment of the application for preparing the master batch b, the temperature of each section of the extruder of the twin-screw granulator is determined according to the melting and plasticizing temperature of the actual mixture: the temperature of the melting and plasticizing section (1st zone) is 160-162°C; the temperature of the melting and plasticizing section (2nd-6th zones) is 170-172°C; the temperature of the melting and plasticizing over section (7th zone) is 150-155°C; the temperature of the plasticizing and cooling section (8th-9th zones) is 135-145°C; the temperature of the plasticizing and cooling section (10th-11th zones) is 129-131°C; and the temperature of the die (12th zone) is 129-131°C.

[0051] In a preferred embodiment of the application, the first warming zone of the low-pressure PE film bag blowing film extruder is 180°C, the second warming zone is 195°C, the third warming zone is 200°C, and the die warming zone is 210°C.

[0052] In a preferred embodiment of the application, the first warming zone of the high-pressure PE film bag blowing film extruder is 150°C, the second warming zone is 160°C, the third warming zone is 165°C, and the die warming zone is 160°C.

[0053] At present, there are high-pressure PE anti-fog master batches in China, but there are no anti-fog master batches specially used for low-pressure PE anti-fog film bags, and there are no multi-strip alternating transparent anti-fog and antibacterial film bags. Although low-pressure PE anti-fog film bags have been sold on the market, they must be mixed with more than 15% high-pressure PE material as an anti-fog agent release carrier during film blowing, and the anti-fog master batch accounts for 12%-16% during the production of the film bag. Even so, the anti-fog effect of the low-pressure PE anti-fog film bag cannot reach the effect of instant anti-fog when sudden temperature difference occurs, that is, when encountering fog. Through sampling and testing of the existing low-pressure PE anti-fog film bag on the market, it is found that the anti-fog film of the existing low-pressure PE anti-fog film bag will immediately fog when covering the mouth of a glass cup containing eight-tenths of boiling water, and then the fog will slowly dissipate, which cannot instantaneously dissipate the fog like pure high-pressure PE anti-fog film bag. Secondly, the existing low-pressure PE anti-fog film bag samples collected are filled with freshly collected four seasons beans, eggplants, and peppers, and are stored at room temperature after being sealed. The results show that on the first day, there are many foggy patches on the film bag, and on the second day, the film bag begins to show the phenomenon of hanging points (water droplets). The anti-fog effect lasts for 3-4 days, and after losing the anti-fog function, the film bag begins to produce black spots and black nodules after being stored for 7 days. It is proved in practice that most anti-fog master batches have irritant and caustic properties, especially for peppers, four seasons beans, eggplants, and other fruits and vegetables with stems, which are easy to cause burns and form black spots or overall discoloration, deterioration, etc.

[0054] CN111218053A discloses a high-transparency anti-fog masterbatch and a preparation method thereof. The expression "high-transparency and bright film" indicates that the patent is directed to high-pressure PE film or a mixed anti-fog film of high and low pressure PE, but not a pure low-pressure PE anti-fog film. This is because the low-pressure PE product film itself has a haze feeling, which determines that a pure low-pressure PE film cannot achieve high transparency. Therefore, the anti-fog masterbatch disclosed in the patent does not belong to the special anti-fog masterbatch for low-pressure PE film bags. CN111518329A discloses a high-content anti-fog masterbatch using white carbon black as an oil storage release agent and a production process thereof. The expression "inorganic powder such as calcium carbonate powder has too large a hiding rate under normal conditions, and the subsequent blown film is not transparent" is also described with respect to high-pressure PE film.

[0055] The processing temperature of low-pressure PE film is generally 50°C higher than that of high-pressure PE film. The die blowing temperature of low-pressure PE film is as high as 210°C. At high temperature, some anti-fog agents may decompose, and in severe cases, the entire vehicle may be filled with smoke. Anti-fog masterbatch using single white carbon black (without special processing) as an oil storage release agent can only be used for high-pressure PE anti-fog film bags. Otherwise, if used to make low-pressure PE anti-fog film bags, a large number of water lines (water flowers) will inevitably be produced, and the film bags cannot produce qualified products. In summary, there is currently no anti-fog masterbatch suitable or specifically used for low-pressure PE anti-fog film bags in China. There is also no anti-burn fruit and vegetable anti-fog and antibacterial masterbatch and film bag product that uses white carbon black and other inorganic powders in coordination and simultaneously adds an antibacterial preservative as an oil storage release agent.

[0056] Compared with the background art, the technical solution has the following beneficial effects:

[0057] 1. When the polyolefin anti-fog and antibacterial masterbatch of the present application is used to make low-pressure PE anti-fog and antibacterial film bags, high-pressure PE material can not be added as an anti-fog agent release agent. The addition amount is generally only 6% to 8% under normal circumstances, which is half of the addition amount (12% to 16%) of the currently marketed anti-fog masterbatch. The same instant anti-fog effect as high-pressure PE film bags can be achieved, the cost can be greatly reduced, and the hanging point phenomenon can be delayed for 3 to 5 days before appearing. The anti-fog time is as long as 6 to 8 days or more. Especially after the anti-fog effect is terminated, the antibacterial and preservative functions continue to play a role, and the actual preservation period is even longer.

[0058] 2. The polyolefin anti-fog and antibacterial masterbatch for low-pressure PE can be used for low-pressure PE anti-fog and is more suitable for high-pressure PE and PP anti-fog. It can also improve or solve the common problem of existing most anti-fog masterbatches that cause burns to fruits and vegetables such as peppers, green beans, and eggplants with stems.

[0059] 3. The present application overcomes the deficiencies of conventional film bags in the prior art, which are all the same film surface, the same thickness, the same aging, and the same transparency. The present application realizes that the initial anti-fog effect has half of the area of the film bag, and the middle and late anti-fog film bags also have half of the area of the film bag that can achieve transparency, and the anti-fog aging is long, and each block can alternate transparency.

[0060] 4. The present application has different blocks of the same film surface staggered co-extrusion, and different blocks of different anti-fog models. The function of the anti-fog and anti-bacterial film bag, and the single-layer or double-layer and three-layer outer layer corresponding to the first anti-fog block and the second anti-fog block of the inner layer or the middle layer are co-extruded at the joint area segment. The outer layer is provided with or not provided with an outer convex thickening segment at the co-extrusion joint. Especially for the single-layer film, the first anti-fog block and the second anti-fog block joint area segment co-extrusion joint are provided with an outer convex co-extrusion thickening segment. Therefore, the problem of poor joint strength of the film bag multi-block joint area segment caused by the large amount of oily additives in the film bag material is also solved. BRIEF DESCRIPTION OF DRAWINGS

[0061] Figures 1 to 6 Schematic diagram of the double-layer structure of Example 8

[0062] Figure 1 Structure schematic diagram of the double-layer co-extrusion die of Example 8 with widened groove cavity in the multi-block joint area segment.

[0063] Figure 2 Schematic diagram of the cross section of the double-layer film bag film of Example 8 (partially).

[0064] Figure 3 Schematic diagram of the use effect of the film bag of Example 8 (one of).

[0065] Figure 4 Schematic diagram of the use effect of the film bag of Example 8 (two of).

[0066] Figure 5 Schematic diagram of the use effect of the film bag of Example 8 (three of).

[0067] Figure 6 Schematic diagram of the use effect of the film bag of Example 8 (four of).

[0068] Figures 7 to 12 Schematic diagram of the single-layer structure of Example 9

[0069] Figure 7 Structure schematic diagram of the single-layer co-extrusion die of Example 9 with widened groove cavity in the multi-block joint area segment.

[0070] Figure 8 Schematic diagram of the cross section of the single-layer film bag film of Example 9 (partially).

[0071] Figure 9 Schematic diagram of the use effect of the film bag of Example 9 (one of).

[0072] Figure 10 Schematic diagram of the use effect of the film bag of Example 9 (2).

[0073] Figure 11 Schematic diagram of the use effect of the film bag of Example 9 (3).

[0074] Figure 12 Schematic diagram of the use effect of the film bag of Example 9 (4).

[0075] Figures 13 to 18 Schematic diagram of the ABA three-layer structure of Example 10. Wherein:

[0076] Figure 13 Schematic diagram of the structure of the ABA three-layer co-extrusion die with locally widened groove cavities in the multi-block connection area of Example 10.

[0077] Figure 14 Schematic diagram of the cross-section (partly) of the ABA three-layer film bag film of Example 10.

[0078] Figure 15 Schematic diagram of the use effect of the ABA three-layer film bag of Example 10 (1).

[0079] Figure 16 Schematic diagram of the use effect of the ABA three-layer film bag of Example 10 (2).

[0080] Figure 17 Schematic diagram of the use effect of the ABA three-layer film bag of Example 10 (3).

[0081] Figure 18 Schematic diagram of the use effect of the ABA three-layer film bag of Example 10 (4).

[0082] Figure 19 Schematic diagram of the structure of the two-layer co-extrusion die with widened groove cavities in the multi-block connection area of Example 11.

[0083] Figure 20 Schematic diagram of the cross-section (partly) of the two-layer film of Example 11.

[0084] Figure 21 Schematic diagram of the use effect of the two-layer film of Example 11

[0085] Figure 22 Schematic diagram of the structure of the ABA three-layer co-extrusion die with widened groove cavities in the multi-block connection area of Example 12.

[0086] Figure 23 Schematic diagram of the cross-section (partly) of the three-layer film of Example 12.

[0087] Figure 24Schematic diagram of the use effect of the three-layer film of Example 12

[0088] Figure 25 Schematic diagram of the structure of the ABC three-layer co-extrusion die of the multi-block connection area segment slot cavity widening of Example 13.

[0089] Figure 26 Schematic diagram of the cross-section of the three-layer film of Example 13 (partial).

[0090] Figure 27 Schematic diagram of the use effect of the three-layer film of Example 13.

[0091] Figure 28 Schematic diagram of the structure of the single-layer co-extrusion die of the multi-block connection area segment slot cavity widening of Example 14.

[0092] Figure 29 Schematic diagram of the cross-section of the single-layer film of Example 14 (partial).

[0093] Figure 30 Schematic diagram of the use effect of the film of Example 14.

[0094] Figure 31 Schematic diagram of the structure of the single-layer co-extrusion die of the multi-block connection area segment slot cavity widening of Example 15.

[0095] Figure 32 Schematic diagram of the cross-section of the single-layer film bag film of Example 15 (partial)

[0096] Figure 33 Schematic diagram of the use effect of the film of Example 15. DETAILED DESCRIPTION

[0097] In the following Examples 1-7,

[0098] LLDPE from Quan Port Petrochemical 7042; LDPE from South Korea Huanhua 955;

[0099] Random polypropylene APP from Dow K7S; EVA from Formosa Plastics 7470M

[0100] Examples 1-3 below are ordinary content anti-fog antibacterial masterbatch for polyolefin low-pressure PE (masterbatch b)

[0101] Example 1 ordinary content anti-fog antibacterial masterbatch for polyolefin low-pressure PE

[0102] The ordinary content anti-fog antibacterial masterbatch for polyolefin low-pressure PE includes the following components by weight (parts by weight): LLDPE 45, LDPE 22, APP 5.0, antioxidant (1010) 0.5, sodium benzoate 3.0, D-sodium isoascorbic acid 2.5, stearic acid 1.0, oleic acid 1.0; stearic acid diethanolamine 10, monoglyceride 10.

[0103] The specific preparation process is as follows:

[0104] First, the plastic carrier 72 (LLDPE, LDPE and APP), antioxidant 0.5, sodium benzoate 3.0, D-sodium isoascorbic acid 2.5, stearic acid 1.0, and oleic acid 1.0 are simultaneously metered and put into a mixer for mixing treatment, and the mixing time is 3 min; then the antifogging agent stearic acid diethanolamine 10 and monoglyceride 10 are mixed for 2 min; after the above materials are fully and uniformly mixed by the mixer, they are melted, plasticized and extruded by a double-screw granulator; the temperature of the melting and plasticizing section (1 zone) of the double-screw granulator is 160°C; the temperature of the melting and plasticizing section (2-6 zones) is 170°C; the temperature of the melting and plasticizing over section (7 zone) is 150°C; the temperature of the plasticizing cooling section (8-9 zones) is 135°C; the temperature of the plasticizing cooling section (10-11 zones) is 129°C; the temperature of the die (12 zone) is 129°C; finally, the product is cooled and cut into polyolefin low-pressure PE ordinary content antifogging antibacterial masterbatch by air cooling.

[0105] Example 2

[0106] The polyolefin low-pressure PE ordinary content antifogging antibacterial masterbatch includes the following components according to the weight ratio: LLDPE 70, EVA 5.0, antioxidant (1010) 0.4, sodium dehydroacetate 2.5, silver ion 2.5, stearic acid 0.8, oleic acid 0.8, stearic acid diethanolamine 8, monoglyceride 8, and polyglycerol oleate 2.0.

[0107] The specific preparation process is as follows:

[0108] First, LLDPE 70, EVA 5.0, antioxidant 0.4, sodium dehydroacetate 2.5, silver ion 2.5, stearic acid 0.8, and oleic acid 0.8 are simultaneously metered and put into a mixer for mixing treatment, and the mixing time is 3 min; then stearic acid diethanolamine 8, monoglyceride 8, and polyglycerol oleate 2.0 are mixed for 3 min; after the above materials are fully and uniformly mixed by the mixer, they are melted, plasticized and extruded by a double-screw granulator; the temperature of the melting and plasticizing section (1 zone) of the double-screw granulator is 161°C; the temperature of the melting and plasticizing section (2-6 zones) is 171°C; the temperature of the melting and plasticizing over section (7 zone) is 153°C; the temperature of the plasticizing cooling section (8-9 zones) is 140°C; the temperature of the plasticizing cooling section (10-11 zones) is 130°C; the temperature of the die (12 zone) is 130°C; finally, the product is cooled and cut into polyolefin low-pressure PE ordinary content antifogging antibacterial masterbatch by air cooling.

[0109] Example 3

[0110] Polyolefin low-pressure PE with ordinary content anti-fog antibacterial masterbatch, according to the weight ratio includes the following components: LLDPE 74.5, EVA 5.0, antioxidant (1010) 0.2. D-sodium isoascorbic acid 1.4, potassium sorbate 1.6, stearic acid 0.6, oleic acid 0.7, stearic acid diethanolamine 5.0, monoglyceride 5.0, polyoxyethylene ether 6.0.

[0111] The specific preparation process is as follows:

[0112] First, the plastic carrier 79.5 (LLDPE and EVA), antioxidant 0.2, D-sodium isoascorbic acid 1.4, potassium sorbate 1.6, stearic acid 0.6, oleic acid 0.7 are simultaneously metered and put into the mixer for mixing treatment, the mixing time is 2 min; then the anti-fog agent stearic acid diethanolamine 5.0, monoglyceride 5.0, polyoxyethylene ether 6.0 are mixed for 3 min. After the above materials are fully and uniformly mixed by the mixer, they are melted, plasticized and extruded by a double-screw granulator; the temperature of the melting and plasticizing section (1 zone) of the double-screw granulator is 162℃; the temperature of the melting and plasticizing section (2 to 6 zones) is 172; the temperature of the melting and plasticizing over section (7 zone) is 155℃; the temperature of the plasticizing cooling section (8 to 9 zones) is 145℃; the temperature of the plasticizing cooling section (10 to 11 zones) is 131℃; the temperature of the die (12 zone) is 131℃; finally, it is cooled and cut into particles by air cooling to form the polyolefin low-pressure PE with ordinary content anti-fog antibacterial masterbatch finished product.

[0113] The following examples 4-7 are high-content anti-fog antibacterial masterbatch (masterbatch a) for multi-strip block alternating transparent film bag

[0114] Example 4

[0115] The high-content anti-fog antibacterial masterbatch for multi-strip block alternating transparent film bag, according to the weight ratio includes the following components: LDPE 18, APP 3.0, white carbon black 26, barium sulfate 12, 1010 antioxidant 0.5, sodium benzoate 2.0, sodium isoascorbic acid 2.0, aluminate coupling agent 1.2, stearic acid 2.5, polyethylene wax 1.0, oleic acid 1.6, stearic acid diethanolamine 15.2, monoglyceride 15.

[0116] The specific preparation process is as follows:

[0117] First, the plastic carrier 21 (LLDPE and APP), inorganic powder 38 (white carbon black and barium sulfate), antioxidant 0.5, sodium benzoate 2.0, sodium erythorbate 2.0 are respectively measured and put into the stirring machine with heating function to stir until the moisture of the material is less than 1%, the mixing time is within 60 minutes, which can be matched with warming; then put in the modifier aluminic ester coupling agent 1.2, and then put in the dispersant 3.5 for surface coating treatment; finally, put in the opening agent 1.6 and the anti-fog agent 30.2 at the same time for mixing; after the above materials are fully mixed and uniform by the stirring machine, melt, plasticize and extrude granulation by the double screw granulator; the temperature of the melt, plasticization section (1-2 zone) of the double screw granulator is 160℃; the temperature of the melt, plasticization section (3-6 zone) is 145℃; the temperature of the melt, plasticization over section (7 zone) is 135℃; the temperature of the plasticization cooling section (8-9 zone) is 100℃; the temperature of the plasticization cooling section (10-11 zone) is 90℃; the temperature of the die head (12 zone) is 85℃; finally, wind cooling and cutting into multiple block alternating transparent film bags with high content anti-fog antibacterial master batch finished product.

[0118] Example 5

[0119] Multiple block alternating transparent film bag with high content anti-fog antibacterial master batch, according to the weight ratio, includes the following components: LDPE 21.5 EVA 5 white carbon black 26 talc 9.0, 1010 antioxidant 0.4, potassium sorbate 3.5, aluminic ester coupling agent 1.0, stearic acid 2.2 polyethylene wax 1.0, oleic acid 1.4, stearic acid diethanolamine 8.0, monoglyceride 8.0, polyoxyethylene ether 13

[0120] The specific preparation process is as follows:

[0121] First, the plastic carrier 26.5, inorganic powder 35, antioxidant 0.4, potassium sorbate 3.5 are respectively measured and put into the stirring machine with heating function to stir until the moisture of the material is less than 1%, the mixing time is more than 45 minutes; then put in the modifier 1.0 and the dispersant 3.2 for surface coating treatment; finally, put in the opening agent 1.4 and the anti-fog agent 29 for mixing; after the above materials are fully mixed and uniform by the stirring machine, melt, plasticize and extrude granulation by the double screw granulator; the temperature of the melt, plasticization section (1-2 zone) of the double screw granulator is 165℃; the temperature of the melt, plasticization section (3-6 zone) is 148℃; the temperature of the melt, plasticization over section (7 zone) is 138℃; the temperature of the plasticization cooling section (8-9 zone) is 110℃; the temperature of the plasticization cooling section (10-11 zone) is 95℃; the temperature of the die head (12 zone) is 90℃, finally wind cooling and cutting into multiple block alternating transparent film bag with high content anti-fog antibacterial master batch finished product.

[0122] Example 6

[0123] The high content anti-fog antibacterial master batch for multi-block alternating transparent film bag comprises the following components in proportion by weight: LDPE 28.5, EVA 5.0, white carbon black 23, talcum powder 10, 1010 antioxidant 0.3, sodium dehydroacetate 3.0, aluminate coupling agent 0.9, stearic acid 2.0, polyethylene wax 1.0, oleic acid 1.3, stearic acid diethanolamine 8.0, monoglyceride 8.0, and polyoxyethylene ether 9.0.

[0124] The specific preparation process is as follows:

[0125] First, the plastic carrier 33.5, the inorganic powder carrier 33, the antioxidant 0.3, and the sodium dehydroacetate 3.0 are respectively measured and added to the stirring machine with heating function to stir the material until the moisture is less than 1%, and the mixing time is more than 38 minutes. Then, the modifier 0.9 and the dispersant 3.0 are added for surface coating treatment, and finally the opening agent 1.3 and the anti-fog agent 25 are added for uniform mixing. After the above materials are fully mixed and uniformly mixed by the stirring machine, they are melted, plasticized, and extruded by a double-screw granulator. The temperature of the melting and plasticizing section (1-2 zone) of the double-screw granulator is 168℃; the temperature of the melting and plasticizing section (3-6 zone) is 153℃; the temperature of the melting and plasticizing over section (7 zone) is 140℃; the temperature of the plasticizing cooling section (8-9 zone) is 115℃; the temperature of the plasticizing cooling section (10-11 zone) is 96℃; and the temperature of the die (12 zone) is 92℃. Finally, the product is cooled and cut into granules to form the high content anti-fog antibacterial master batch for multi-block alternating transparent film bag.

[0126] Example 7

[0127] The high content anti-fog antibacterial master batch for multi-block alternating transparent film bag comprises the following components in proportion by weight: LDPE 36, EVA 5.0, white carbon black 20, talcum powder 10, 1010 antioxidant 0.2, silver ion 2.0, aluminate coupling agent 0.8, stearic acid 1.8, polyethylene wax 1.0, oleic acid 1.2, stearic acid diethanolamine 7.0, monoglyceride 7.0, and Tween 8.0

[0128] The specific preparation process is as follows:

[0129] First, the plastic carrier 41, inorganic powder carrier 30, antioxidant 0.2, silver ions 2.0 are respectively measured and put into a stirring machine with heating function to stir until the moisture of the material is less than 1%, the mixing time is more than 30 minutes, then put in modifier 0.8, dispersant 2.8 for surface coating treatment, finally put in opening agent 1.2, anti-fog agent 22 for mixing. After the above materials are fully mixed and uniform by the stirring machine, they are melted, plasticized, and extruded into granules by a double screw granulator. The temperature of the melting and plasticizing section (1-2 zone) is 170°C; the temperature of the melting and plasticizing section (3-6 zone) is 155°C; the temperature of the melting and plasticizing section (7 zone) is 142°C; the temperature of the plasticizing and cooling section (8-9 zone) is 120°C; the temperature of the plasticizing and cooling section (10-11 zone) is 100°C; the temperature of the die (12 zone) is 95°C. Finally, the wind cooling and cutting are carried out to form a plurality of block transparent film bags with high content of anti-fog antibacterial masterbatch finished product.

[0130] In the following film bag preparation:

[0131] HDPE9001 from Formosa Plastics; HDPE7000F from Iran Petrochemical;

[0132] LLDPE7042 from Fujian Quan Port Petrochemical; LDPE2426K from Daqing Petrochemical;

[0133] POE from Exxon POEVM6102; metallocene from Exxon Mobil 6026 ML

[0134] Preparation of film bag:

[0135] Film bag one. Pure low pressure HDPE9001 77%, example 4 masterbatch a 10%, metallocene 5.0%, POE 8.0%, the extruder die temperature is adjusted to 210°C, the film blowing process is the same as the traditional one, the film bag is prepared, the film thickness is about 0.02mm (2 silk).

[0136] Film bag two. Low pressure HDPE 69%, high pressure PE 10%, example 3 masterbatch b 8.0%, metallocene 5.0%, POE 8.0%, the extruder die temperature is adjusted to 210°C, the film blowing process is the same as the traditional one, the film bag is prepared, the film thickness is about 0.02mm (2 silk).

[0137] The low-pressure PE anti-fog film bag blown by the high-content anti-fog antibacterial master batch of the plurality of block alternately high-transparency film bags is compared with the existing good low-pressure PE anti-fog film bag, the general low-pressure PE anti-fog film bag on the market, and the low-pressure PE anti-fog film bag blown by the existing white carbon black oil storage anti-fog master batch (CN202010420444.6, the addition proportion is also 10%, the rest is pure low-pressure HDPE 900177%, metallocene 5.0%, POE 8.0%). According to the evaluation basis of the good and bad of the anti-fog film bag, the anti-fog transparency, the anti-fog time, whether the anti-fog can be instantaneous, whether the anti-fog will burn the fruits and vegetables, and other conditions are generally selected. Finally, through the common discussion and seeking opinions with many planting carrot, potato, especially pepper, eggplant, and green bean, etc. vegetable growers who are easy to be burned by the anti-fog agent, two kinds of anti-fog film bags that are recognized as the best or general by them are selected and purchased from them, and the fruit and vegetable objects are purchased on site. And the test and detection are carried out according to their specific environmental requirements. The above five kinds of plastic anti-fog bags are filled with just brought back carrots, peppers, eggplants, etc., and the humidity and water absorption capacity of the inner surface of the bag are observed at the same time every day. Once the film surface absorbs water and is wet, the film becomes more transparent. However, when the film surface reaches a completely water-saturated state, the water film becomes water droplets, and if the water droplets continue to increase, the film becomes opaque. The table is classified and evaluated according to the local foggy patches, water film formation, local water droplets, more water droplets, and many water droplets. The results are shown in Table 1.

[0138] Table 1 Comparison of the effects of low-pressure PE film bags blown by various anti-fog master batches

[0139]

[0140]

[0141] Through the experimental detection comparison of the anti-fog film bag selected by the above market and the film bag (film bag two) made by the ordinary content anti-fog antibacterial master batch of Example 3, the market existing good anti-fog film bag preserved pepper, eggplant, and green bean with stems starts to appear local black spots and black stems on the 7th day of preservation and storage; the film bag (low-pressure film bag two) made by the ordinary content anti-fog antibacterial master batch of Example 3 has poor transparency on the 7th day, but no black spots and black stems are found, and the water retention, color, and stiffness are better than the market selected anti-fog film bag.

[0142] The film bag (film bag one) made by the high-content anti-fog antibacterial master batch a of Example 4 has relatively poor transparency compared to the high-transparency film bag on the market when it is used, but the anti-fog, transparency, and antibacterial time are better than film bag two (more than four days at the longest), and are better than the traditional film bag (more than a week at the longest), and the preservation and storage period of the pepper, eggplant, and green bean with stems is longer, and local black spots and black stems are not easy to appear, and the water retention, color, and stiffness are improved, and the anti-fog antibacterial preservation effect is improved compared to the traditional anti-fog film bag.

[0143] In addition, it is also suitable for making high pressure film bags:

[0144] Film bag three. Linear high pressure LLDPE 74%, high pressure LDPE 12%, POE 5%, opening master batch 3%, master batch b prepared by example 3 6%, the extruder die temperature is adjusted to 160°C, and the film bag is prepared by using the existing film blowing process, and the film thickness is about 0.04 mm (4 silk). The product is qualified, and the anti-fog and antibacterial effects are similar to those of the low pressure film bag.

[0145] Film bag four. Linear high pressure LLDPE 72%, high pressure LDPE 12%, POE 5%, opening master batch 3%, master batch a prepared by example 4 8%, the extruder die temperature is adjusted to 160°C, and the film bag is prepared by using the existing film blowing process, and the film thickness is about 0.04 mm (4 silk). The product is qualified, and the anti-fog and antibacterial effects are similar to those of the low pressure film bag.

[0146] The anti-fog master batch of examples 1-3 and examples 4-7 is added in different staggered strip blocks respectively to make the high pressure or low pressure PE multi-strip block alternating transparent anti-fog antibacterial film bag of the application: see examples 8 to 12.

[0147] Example 8: Preparation of double-layer co-extrusion alternating transparent film bag

[0148] See Figure 1 In order to provide a multi-strip block alternating transparent anti-fog antibacterial film bag, the applicant provides a multi-strip block groove cavity connection area segment widened co-extrusion die, which is in the shape of a ring and includes an inner layer flow channel 1' and an outer layer flow channel 2'. The inner layer flow channel 1' includes A' areas and B' areas arranged alternately in the circumferential direction. In this embodiment, the A' areas and the B' areas are four respectively, arranged as A'B'A'B'A'B'A'B'. The outer layer flow channel 2 corresponding to the A' and B' connection seam area is provided with a locally outwardly convex widened segment area C' (the "width" of the die refers to the radial direction rather than the circumferential direction).

[0149] The groove cavity width (i.e. the distance in the diameter direction, including the widened segment c') of the outer layer flow channel 2' is 1 / 2 to 2 / 2 of the groove cavity width of the inner layer flow channel 1', and the width of the outwardly convex widened segment area c' of the outer layer flow channel itself accounts for 10-50% of the width of the groove cavity of the outer layer flow channel 2', and the widened segment c' spans the A' and B' connection places. The arc length growth segment c' extends 2.5-20 mm clockwise and counterclockwise along the circumferential direction of the connection seam.

[0150] The co-extrusion die is connected with three extruders, and the outflow units of the three extruders are respectively connected with the groove cavities of two A' and B' flow channels and an outer layer flow channel which are staggered and segmented in the inner layer. The two A and B flow channels are alternately arranged in the vertical direction and extruded at the same time as the outer layer flow channel 2'. The A' and B' regions are respectively provided with different anti-fog master batches which are selected by staggering the feeding hoppers before the flow channels. The outer layer flow channel is not provided with anti-fog master batch. The co-extrusion die is used for co-extrusion, inflation, stretching and winding to form an A and B staggered and parallel segmented co-extrusion inner layer which is simultaneously connected with the outer layer flow channel to form a co-extrusion film bag structure. Figure 1 (co-extrusion coating around the circumference) outer layer co-extrusion Figure 3 、 Figure 4 A and B block film bag structure.

[0151] Referring to Figures 2 to 4 , the application provides a multi-block connection area groove partially widened double-layer co-extrusion film bag, which comprises an inner layer 1 and an outer layer 2, wherein the inner layer 1 is provided with A and B alternately arranged anti-fog blocks, and the outer layer 2 is provided with a locally thickened segment C corresponding to the A' and B' region connection area segments of the inner layer.

[0152] The A block is a first anti-fog block, and the B block is a second anti-fog block. The two blocks have different transparent periods and different anti-fog time effectiveness. When preparing a low-pressure PE anti-fog antibacterial type alternating transparent film bag:

[0153] The first anti-fog block is a short-acting and initial transparent block. The anti-fog block is added with the ordinary content anti-fog antibacterial master batch for low-pressure PE in Example 3. Specifically, the material ratio is that the anti-fog antibacterial master batch in Example 3 accounts for 8% of the total formula, HDPE (Taizhong 9001) 67%, LDPE (Daqing Petrochemical 2426K) 15%, metallocene (Exxon Mobil 6026ML) 5%, and POE (Exxon 6102) 5%.

[0154] The second anti-fog block is a long-acting and middle-late transparent anti-fog block. The anti-fog block is added with the high content anti-fog antibacterial master batch for polyolefin low-pressure PE in Example 4. Specifically, the material ratio is that the anti-fog antibacterial master batch in Example 4 accounts for 10% of the total formula, HDPE (Iran 7000F) 62%, LDPE (Daqing Petrochemical 2426K) 15%, metallocene (Exxon Mobil 6026ML) 5%, and POE (Exxon 6102) 8%.

[0155] The outer layer 2 is a common transparent layer, i.e. a film layer without anti-fog master batch. Specifically, the material ratio is that HDPE (Taizhong 9001) accounts for 75%, LDPE (Daqing Petrochemical 2426K) accounts for 15%, metallocene (Exxon Mobil 6026ML) accounts for 5%, and POE (Exxon 6102) accounts for 5%. The thickened segment C of the outer layer 2 is arranged at the connection seam between the A block and the B block.

[0156] The film bag isFigure 1 The multi-block connecting area groove widening co-extrusion die shown is used to prepare the material.

[0157] The preparation method of the double-layer low-pressure PE anti-fog and antibacterial alternating transparent film bag is as follows: three extruders are used for co-extrusion, with the outflow units of two extruders connected to the inner layer regions A and B respectively. The feed hoppers of the flow channels corresponding to regions A and B are staggered and anti-fog and antibacterial masterbatches of Example 4 and Example 3 are added respectively. The outflow unit of the third extruder is connected to the outer layer (without adding anti-fog masterbatch).

[0158] Bag making method: Low-pressure PE film bag blown film extruder with first heating zone 180℃, second heating zone 195℃, third heating zone 200℃, and die head heating zone 210℃.

[0159] When using the film bag of this invention, it is initially transparent, although half of it is relatively transparent. Starting on the second or third day after fruit or vegetables are placed inside, section A, which was initially transparent, begins to show more streaks and gradually becomes blurry (see...). Figure 4 (Illustration); After the second or third day of use, conversely, when strip A begins to blur, strip B, having absorbed some water, begins to exhibit the water-reactive glass effect, changing from generally transparent to completely transparent (see...). Figure 3 (Illustration)

[0160] In the preparation of high-pressure PE anti-fogging and antibacterial alternating transparent film bags:

[0161] The first anti-fog strip contains the following components: 71% linear high-pressure LLDPE, 12% high-pressure LDPE, 10% toughening agent, 3% open-face masterbatch, and 4% ordinary content anti-fog and antibacterial masterbatch for low-pressure polyolefin PE prepared in step B.

[0162] The second anti-fog strip contains the following components: 69% linear high-pressure LLDPE, 12% high-pressure LDPE, 10% toughening agent, 3% open-cell masterbatch, and 6% high-content anti-fog and antibacterial masterbatch for low-pressure polyolefin PE prepared in step A.

[0163] The outermost layer 2 is a regular transparent layer, alternating with the previous low-pressure PE anti-fog and antibacterial transparent film bag.

[0164] The film bag is made of Figure 1 The multi-block connecting area cavity widening co-extrusion die shown is prepared. Three extruders with two-layer co-extrusion dies are used, with the outflow units of two extruders connecting areas A and B respectively, and one extruder connecting to the outer layer 2. The high-pressure PE film bag blown film extruder has a first heating zone of 150℃, a second heating zone of 160℃, a third heating zone of 165℃, and a die head heating zone of 160℃.

[0165] See Figures 2-6In use effect, the high-pressure PE anti-fog antibacterial film bag and the low-pressure PE anti-fog antibacterial type alternating transparent film bag are similar, and the low-pressure PE fruit and vegetable heavy packaging film bag generally has a film bag handle belt (such as Figure 5 and Figure 6 );The high-pressure PE film bag is not a heavy packaging bag, that is, the film bag generally does not have a handle belt, and directly seals and cuts a flat film bag. The rest of the structure, function and the like are the same (see Figures 3-4 ), such as especially suitable for making the current best-selling mushroom anti-fog fresh-keeping flat film bag.

[0166] Example 9: Preparation of a single-layer co-extrusion alternating transparent film bag

[0167] Referring to Figure 7 , in another embodiment, the present application can also use a multi-bar block joint area local outward convex co-extrusion die head shown in Figure 7 , the co-extrusion die head groove is circular in shape, including D areas and E areas alternately arranged in the circumferential direction. In this embodiment, the D areas and the E areas are four, arranged as DEDEDEDE.

[0168] Among them, at the joint of D and E, the joint seam area of the D area and the E area is locally outward convexly provided with a widened section. As shown in Figure 7 , the two ends of the D area near the joint seam are respectively provided with widened section areas D1 and D2; The two ends of the E area near the joint seam are respectively provided with widened section areas E1 and E2. In the present application, the "width" of the die head refers to the radial direction rather than the circumferential direction.

[0169] The groove width of the present layer (i.e. the distance in the diameter direction, which is the widened width of the widened section c' of the present layer without widening) is 10%-50% of the widened width of the D and E present layers without widening, and the length (circumferential direction) of the arc length of the widened section area is 2.5-20mm in each of the clockwise and counterclockwise directions along the circumferential direction.

[0170] Referring to Figures 8-10 , another multi-bar block joint area outward convex structure co-extrusion film bag provided by the present application, the film bag includes D' and E' blocks alternately arranged, the joint line of the D' block or the E' block is locally thickened respectively, the thickening thickness is 10%-50% of the D' or E' area respectively, and the width of the thickening section span area is 10-40mm in each of the left and right directions of the joint line.

[0171] Among them, the D' block is a first anti-fog block, and the E' block is a second anti-fog block, and the anti-fog time efficiency of the two is different, and the transparency period is also different.

[0172] The first anti-fog block is an initial transparent, short-acting anti-fog block, and the second anti-fog block is a long-acting, mid-late transparent anti-fog block.

[0173] The film bag is made of Figure 7 The co-extrusion die, shown, is prepared by locally widening the arc-shaped groove connection area of ​​multiple conveying channels. This co-extrusion die is equipped with two extruders, whose outlet units are respectively connected to regions D and E. The feed hoppers of the preceding processes corresponding to regions D and E are staggered and respectively select anti-fogging and antibacterial masterbatches from Examples 1 and 4.

[0174] Bag making method:

[0175] When preparing low-pressure PE anti-fogging and antibacterial alternating transparent film bags:

[0176] The first anti-fog strip is an anti-fog strip with added low-pressure PE common content anti-fog and antibacterial masterbatch from Example 1. Specifically, its material ratio is as follows: anti-fog and antibacterial masterbatch from Example 3 accounts for 8% of the total formula, HDPE (Formosa Plastics 9001) 64%, LDPE (Daqing Petrochemical 2426K) 15%, metallocene (ExxonMobil 6026ML) 5%, and POE (Exxon 6102) 8%.

[0177] The second anti-fog strip is a long-lasting, later-transparent anti-fog strip, using the high-content anti-fog and antibacterial masterbatch for low-pressure polyolefin PE of Example 4. Specifically, its material ratio is as follows: anti-fog and antibacterial masterbatch of Example 4 accounts for 10% of the total formula, HDPE (Formosa Plastics 9001) 65%, LDPE (Daqing Petrochemical 2426K) 15%, metallocene (ExxonMobil 6026ML) 5%, and POE (Exxon 6102) 5%.

[0178] The low-pressure PE film bag blown film extruder has a first heating zone of 180℃, a second heating zone of 195℃, a third heating zone of 200℃, and a die head heating zone of 210℃.

[0179] When using the film bags, they are initially transparent. After filling them with fruits or vegetables, strip D' becomes initially transparent for a short period, while strip E' remains generally transparent (see [link]). Figure 9 or Figure 11 After a period of use, stripe D' loses its transparency, while stripe E' becomes transparent due to the water film effect (see...). Figure 10 Or 12).

[0180] In the preparation of high-pressure PE anti-fogging and antibacterial alternating transparent film bags:

[0181] The first anti-fog strip contains the following components: 75% linear high-pressure LLDPE, 12% high-pressure LDPE, 5% toughening agent, 3% open-face masterbatch, and 5% of the common content anti-fog and antibacterial masterbatch for low-pressure polyolefin PE prepared in step B.

[0182] The second anti-fog strip block contains components: linear high-pressure LLDPE 74%, high-pressure LDPE 12%, toughening agent 5%, opening master batch 3%, polyolefin low-pressure PE high-content anti-fog antibacterial master batch a prepared by step A 6%

[0183] The first warming area of the high-pressure PE film bag blowing film extruder is 150 ℃, the second warming area is 160 ℃, the third warming area is 165 ℃, and the die warming area is 160 ℃.

[0184] The effect is similar to that of the low-pressure PE anti-fog antibacterial type alternating transparent film bag.

[0185] Preparation of a three-layer co-extrusion ABA structure film bag

[0186] Referring to Figure 13 , the three-layer (ABA) structure schematic diagram of the multi-strip block connection area segment groove widening co-extrusion die is a circular shape, including an inner layer flow channel groove 1', an outer layer flow channel groove 2', and a middle layer flow channel groove 3'. The middle flow channel groove 3' includes A' areas and B' areas arranged alternately in the circumferential direction. In this embodiment, the A' areas and the B' areas are four respectively, arranged as A'B'A'B'A'B'A'B'. The outer layer flow channel groove 2' is provided with a local outwardly convex widening segment C' at the connection of the A' and B' of the middle flow channel groove 3. The width of the inner layer flow channel groove 1 is more than twice the width of the outer layer flow channel 2 without widening.

[0187] The co-extrusion die is connected with three extruders. Two of the three extruders are connected with the A' and B' flow channels respectively, and the other one is connected with the grooves of the inner layer flow channel 1' and the outer layer flow channel 2'. The A and B flow channels of the middle layer are alternately staggered and transversely arranged for extrusion, and are also extruded co-extrusion with the outer layer flow channel 2' and the inner layer flow channel 1'. The flow channels corresponding to the A' areas and the B' areas are respectively staggered and selected to add the low-pressure high-content anti-fog antibacterial master batch of the application (or the existing high-content anti-fog master batch) or the existing low-content ordinary anti-fog master batch in the pre-process feeding hopper. The outer layer and the inner layer flow channel share one pre-process feeding hopper to add the ordinary content anti-fog master batch. One machine is connected with the inner and outer layer grooves through two flow channels, and is also connected with two different strip groove channels of the same layer through the other two machines respectively. Through co-extrusion, blowing, organ folding, and winding, an A and B staggered and side-by-side interval co-extrusion middle layer is formed, and a Figures 14-18 The A and B strip blocks are alternately transparent film structures.

[0188] Referring to Figure 13 , Figure 14 , Figures 17-18This embodiment provides a three-layer co-extruded film with locally widened outer cavity in the multi-strip connection area (the inner and outer layers share the same flow channel as a high-pressure PE layer, and the middle layer is a low-pressure PE layer). The film includes an inner layer 1, an outer layer 2, and a middle layer 3. The middle layer 3 has alternating A and B strips. The thickness of the inner layer 1 is more than twice the thickness of the outer layer 2 before thickening. The outer layer 2 (to cover the matte appearance of the low-pressure PE middle layer, it is equivalent to coating only a very thin layer of high-pressure PE on the surface as a brightening layer) has a locally thickened section C. The thickness of the thickened section C is 10%-200% (150% in this embodiment) of the non-thickened section of the outer layer 2. The width of the thickened section spans 5.0-40mm in each direction of the connection line (15mm in this embodiment).

[0189] Among them, block A is the first anti-fog block, and block B is the second anti-fog block. Their transparency periods and anti-fog durations differ. The first anti-fog block is initially transparent but has a short duration, while the second anti-fog block is more durable and transparent after being moistened by water vapor. The outer layer 2 and inner layer 1 are auxiliary anti-fog and antibacterial transparent layers, i.e., film layers with a low content of ordinary anti-fog masterbatch. The thickened section C is located at the joint between blocks A and B.

[0190] The membrane is made of Figure 13 The multi-block connecting area groove widening co-extrusion die shown is used to prepare the material.

[0191] The components and preparation methods of blocks A and B are the same as in Example 8, and the components of the ordinary transparent layer (i.e., the inner and outer layers) are the same as in Example 8.

[0192] For usage effects, please refer to [link / details]. Figures 15-18 Similar to Example 8, the transparency alternates. That is, initially all sections are transparent, but half are relatively transparent. Starting on the second or third day after fruit or vegetables are added, section A, initially transparent, gradually becomes less transparent and starts to become more blurred (see Example 8). Figure 15 or Figure 17 (Illustration); After the second or third day of use, conversely, when strip A begins to blur, strip B, having absorbed some water, begins to exhibit the water-reactive glass effect, changing from generally transparent to completely transparent (see...). Figure 16 or Figure 18 (Illustration)

[0193] In another implementation (ABC structure), alternating A and B strips can be provided in the inner layer 1, while the outer layer 2 and the middle layer 3 do not have alternating A and B strips.

[0194] Example 11: Double-layer co-extrusion

[0195] See Figure 19This is a schematic diagram of the structure of the multi-layer, multi-block joint section cavity widening co-extrusion die of the present invention. The co-extrusion die is annular in shape and includes an inner flow channel cavity 1' and an outer flow channel cavity 2'. The inner flow channel cavity 1' includes regions A' and B' alternately arranged along the circumferential direction. In this embodiment, there are four regions A' and four regions B', arranged as A'B'A'B'A'B'A'B'.

[0196] An overlap area C' is provided between regions A' and B' of the inner flow channel 1'. The overlap area C' is a tongue that extends 1 / 2 of its own width from the ends of regions A' and B' respectively. The two tongues overlap each other (the "width" of the die head refers to the radial direction rather than the circumferential direction). At the overlap seam on the outer edge of the inner flow channel cavity 1', a locally protruding overlap reinforcement section D' is provided to cover the overlap seam. The width of the protruding overlap reinforcement section D' is 10-50% of the width of the inner non-widened section. Its arc length across the junction of the first and second regions is 2.5-20mm extending clockwise and counterclockwise from the center line of the junction.

[0197] In another embodiment, the lap joint reinforcement section may be omitted.

[0198] Similar to Example 8, this co-extrusion die is connected to three extruders.

[0199] See Figure 20 and Figure 21 This invention provides a multi-layer, multi-strip joint area widened double-layer co-extruded film bag (low-pressure PE vest film bag). The film bag includes an inner layer 1 and an outer layer 2. The inner layer 1 has alternating strips A and B. An overlap area C is provided between the A and B strips of the inner layer 1. The overlap area C is a flap extending 1 / 2 of its own width from the ends of the A and B areas, and the two flaps overlap each other. On the surface of the inner layer 1, a protruding thickened section D is provided at the overlap to cover the overlap.

[0200] In another embodiment, the convex thickening segment D may be omitted.

[0201] Block A is the first anti-fogging block, and block B is the second anti-fogging block. Their high transparency periods and anti-fogging durations differ. The first anti-fogging block contains a normal amount of anti-fogging and antibacterial masterbatch, making it an initially high-transparency, short-lasting type of anti-fogging and antibacterial block. The second anti-fogging block contains a high amount of anti-fogging and antibacterial masterbatch, making it a more durable type of anti-fogging block with high transparency in the later stages. Outer layer 2 is a normal transparent layer, either without anti-fogging masterbatch or with high-barrier additives.

[0202] The above film bags are made by Figure 19 The film bag is prepared by a co-extrusion die that locally widens the cavity of the multi-block connecting area, and the blown film process is the same as the traditional process. This film bag can be processed into a low-pressure PE heavy-duty packaging film bag for fruits and vegetables with handles.

[0203] In addition, the film bag structure of the present embodiment is also applicable to high-pressure PE mushroom anti-fog antibacterial flat-mouth film bags, high-low pressure PE or PP anti-fog antibacterial supermarket box cover films, etc.

[0204] When the film bag is used, the A and B blocks are transparent at the beginning, but half of them are high transparent. After the fruit or vegetable is put in for about one day, the A block gradually changes from high transparent to start fogging and gradually becomes blurred; on the contrary, when the A block starts to blur, the B block is wet at this time because the film surface absorbs a certain amount of water, the glass starts to be transparent due to the effect of water, and the film surface starts to be high transparent accordingly.

[0205] Example 12 Three-layer co-extrusion ABA structure

[0206] Referring to Figure 22 The structure of the co-extrusion die for widening the groove of the multi-block connection area of the present application is shown in the figure. The co-extrusion die is in the shape of a ring and includes an inner flow channel groove 1', an outer flow channel groove 2' and a middle flow channel groove 3'. The middle flow channel groove 3' includes A' areas and B' areas arranged alternately along the circumferential direction. In the present embodiment, there are four A' areas and four B' areas respectively, arranged as A'B'A'B'A'B'A'B'.

[0207] A lap joint area C' is provided between the A' areas and the B' areas of the middle flow channel groove 3'. The lap joint area C' is a lap tongue with a width of 1 / 2 of the width of the A' areas and the B' areas respectively, and the two lap tongues are connected inside and outside (the "width" of the die refers to the radial direction rather than the circumferential direction). A locally widened convex reinforcing section D' is provided at the outer edge of the inner layer corresponding to the middle layer lap joint. The width of the convex reinforcing section D' is 10-50% of the width of the non-widened section of the inner layer, and the arc length of the convex reinforcing section D' across the connection area of the first area and the second area is 2.5-20 mm in the clockwise and counterclockwise directions from the center line of the connection area.

[0208] In another embodiment, the convex reinforcing section D' can not be provided.

[0209] The co-extrusion die is connected to three extruders as in example 10.

[0210] Referring to Figure 23 and Figure 24 The present application provides a three-layer co-extruded film with a locally widened groove in the connection area of multiple blocks. The film includes an inner layer 1, an outer layer 2 and a middle layer 3. The middle layer 3 is provided with A and B blocks arranged alternately. A lap joint area C is provided between the A and B blocks. The lap joint area C is a lap tongue with a width of 1 / 2 of the width of the A and B areas respectively, and the two lap tongues are connected inside and outside. A locally convex lap joint reinforcing section is provided at the outer edge of the inner layer corresponding to the middle layer lap joint.

[0211] Wherein, the A block is the first anti-fog block, the B block is the second anti-fog block, the high transparency period of the two is different, and the anti-fog time is different. The first anti-fog block is an initial high transparency, short time anti-fog block, and the second anti-fog block is a high transparency, long time anti-fog block after the film is wetted by water vapor. The outer layer 2 and the inner layer 1 are auxiliary anti-fog and antibacterial transparent layers, that is, the film layer of the ordinary anti-fog master batch with low content is added. The thickening section D is arranged at the outer edge of the inner layer corresponding to the joint of the A block and the B block of the middle layer.

[0212] In another embodiment, the outer convex thickening section D can also not be arranged.

[0213] The film is prepared by a multi-block joint area groove partial outer convex widening co-extrusion die shown in the drawing. Figure 22

[0214] The film bag of the embodiment is suitable for ABA high and low pressure mixed anti-fog and antibacterial fruit and vegetable heavy packaging film bag (containing handle structure) and high and low pressure PE and PP anti-fog and antibacterial film.

[0215] When the film of the application is used, it is initially transparent, but half of it is initially high transparency. After the fruits or vegetables are loaded, the A block starts to change from high transparency to gradually blurred with many starting points on the second day. On the contrary, the B block generally changes to high transparency after the film is wetted by water vapor on the second or third day, because the film surface absorbs a certain amount of water to form a wet film, the high transparency effect of glass starts, and the film surface starts to change to high transparency accordingly.

[0216] Example 13: three-layer co-extrusion (ABC structure)

[0217] Referring to Figure 25 The co-extrusion die is a circular shape, and includes an inner layer flow channel groove 1', an outer layer flow channel groove 2', and a middle layer flow channel groove 3'. The inner layer flow channel groove 1' is arranged to include A' areas and B' areas arranged alternately along the circumferential direction. In this embodiment, the A' areas and the B' areas are each four, and are arranged as A'B'A'B'A'B'A'B'.

[0218] The A' areas and the B' areas of the inner layer flow channel groove 1' are provided with a lap joint area C'. The lap joint area C' is that the ends of the A' areas and the B' areas respectively extend by 1 / 2 of the width of the A' areas and the B' areas to form two lap joints (the "width" of the die refers to the radial direction, not the circumferential direction). A partial outer convex lap joint reinforcing section D' is arranged at the outer edge of the joint of the inner layer flow channel groove 1'. The width of the outer convex lap joint reinforcing section D' is 10-50% of the non-widened section of the inner layer, and the arc length of the outer convex lap joint reinforcing section D' across the joint of the first area and the second area is 2.5-20 mm in the clockwise and counterclockwise directions from the center line of the joint.

[0219] ​In another embodiment, the outwardly protruding lap joint reinforcement section D may be omitted.

[0220] The co-extrusion die connects to four extruders.

[0221] See Figure 26 and Figure 27 The present invention provides a three-layer co-extruded film with a widened external convexity in the cavity of a multi-block connecting area. The film includes an inner layer 1, an outer layer 2 and an intermediate layer 3. The inner layer 1 is provided with alternating blocks A and B. An overlap area C is provided between the blocks A and B. The overlap area C is a tongue that extends 1 / 2 of its own width from the ends of the A area and the B area, and the two tongues overlap each other.

[0222] In this design, inner layer 1 has two anti-fogging layers: inner layer A, which is a first anti-fogging layer with a normal content of anti-fogging masterbatch, and inner layer B, which is a second anti-fogging layer with a high content of anti-fogging masterbatch. Their high transparency periods and anti-fogging durations differ. The first anti-fogging layer is initially highly transparent but has a short duration, while the second anti-fogging layer is longer-lasting; its high transparency begins after two or three days when the glass comes into contact with water, and it is a more durable anti-fogging layer. Outer layer 2 is a highly transparent film without anti-fogging masterbatch, and middle layer 3 is a film layer with or without anti-fogging masterbatch. The reinforcing and thickening section D is located at the seam between inner layer 1's inner layer A and inner layer B. In another embodiment, the reinforcing and thickening section D may be omitted.

[0223] The membrane is made of Figure 25 The film shown is prepared by a co-extrusion die that widens the convex groove of the multi-block connecting area. The film of this embodiment is suitable for high-pressure PE anti-fog and antibacterial flat-mouth film bags for mushrooms, low-pressure anti-fog and antibacterial heavy packaging film bags for fruits and vegetables (including handle structure), high and low pressure PE or PP anti-fog and antibacterial supermarket box lid films, etc. It is also suitable for strip-shaped alternating high-transparency anti-fog and drip-proof greenhouse films, and is more suitable for traditional greenhouse films or recently popular anti-fog and drip-proof coated greenhouse films with local thickening and reinforcement structures.

[0224] When the membrane of this invention is used, it is initially transparent, but half of it is highly transparent. Starting from the second day after fruits or vegetables are placed inside, the A strip changes from being initially highly transparent to becoming increasingly blurry due to the presence of moisture. Conversely, when the B strip encounters moisture, the membrane surface absorbs a certain amount of water, forming a wetted membrane. The glass transparency effect when exposed to water begins, and the membrane surface correspondingly becomes highly transparent.

[0225] Example 14 Single-layer film bag

[0226] See Figure 28 This is a schematic diagram of a co-extrusion die head with multiple block connection areas according to this embodiment. The cavity of the co-extrusion die head is annular in shape and includes a first region 10 and a second region 20 that are alternately arranged around the circumference. In this embodiment, there are four first regions 10 and four second regions 20, which are arranged alternately along the circumference.

[0227] The first region 10 and the second region 20 are connected by a laminated overlap region, wherein the laminated overlap region of the first region 10 comprises the first laminated layer 11 and the outer convex widened section 12, and the laminated overlap region of the second region 20 comprises the second laminated layer 21 and the inner convex widened section 22. The first laminated layer 11 is on the outside, and the second laminated layer 21 is on the inside, and the two are combined as part of a circular ring. The outer convex widened section 12 spans the first laminated layer 11 and the connection seam of the second region, and the inner convex widened section 22 spans the second laminated layer 21 and the connection seam of the first region.

[0228] In the present application, the "width" of the die slot cavity refers to the radial direction rather than the circumferential direction.

[0229] The widened width of the widened section area of the outer convex widened section 12 or the inner convex widened section 22 is 10-50% of the non-widened width of the first region slot cavity or the second region slot cavity, and the arc length (circumferential direction) of the widened section area is 2.5-20 mm in the clockwise and counterclockwise directions along the circumferential direction of the connection line of the two regions.

[0230] The co-extrusion die is provided with two extruders, and the outflow units of the two extruders are connected to the first region slot cavity and the second region slot cavity, respectively. The two region corresponding flow channel pre-process feeding hoppers are staggered and respectively selected to add high content, long-acting late high transparency or low content early high transparency, short aging anti-fog drop master batch.

[0231] Referring to Figure 29 and Figure 30 The present application provides a multi-strip block connection region convex structure co-extrusion film, which comprises alternating first strip 10' and second strip 20', and a laminated overlap region is arranged between the first strip 10' and the second strip 20', wherein the laminated overlap region of the first strip 10' comprises a first laminated layer 11' and an outer convex thickening section 12', and the laminated overlap region of the second region 20' comprises a second laminated layer 21' and an inner convex thickening section 22'. The first laminated layer 11' is on the outside, and the second laminated layer 21' is on the inside, and the two are combined as part of the film. The outer convex thickening section 12' spans the first laminated layer 11' and the connection seam of the second region; and the inner convex thickening section 22' spans the second laminated layer 21' and the connection seam of the first region. The film bag with high color printing requirements can not be provided with an outer convex widened section.

[0232] The thickness of the thickening section area of the outer convex thickening section 12' or the inner convex thickening section 22' is 10-50% of the non-thickened thickness of the first region or the second region, and the length of the thickening section across the regions is 5.0-40 mm in the left and right directions of the connection line.

[0233] The first strip block 10' is a first anti-fog strip block added with common content anti-fog master batch, and the second strip block 20' is a second anti-fog strip block added with high content anti-fog master batch, and the anti-fog time efficiency of the two is different.

[0234] The first anti-fog strip block is an anti-fog strip block with high initial transparency and short time efficiency, and the second anti-fog strip block is an anti-fog strip block with long time efficiency and high transparency in the middle and later stages.

[0235] The film is prepared by a multi-strip conveying flow channel circular arc groove cavity joint area locally widened outer convex co-extrusion die. Figure 28 The film is prepared by a multi-strip conveying flow channel circular arc groove cavity joint area locally widened outer convex co-extrusion die.

[0236] When the film is used, all the strip blocks are transparent at the beginning, and after the fruits or vegetables are loaded, the first strip block 10' has high initial transparency (about one day), and the second strip block 20' has general transparency; after one day of use, the first strip block 10' gradually loses high transparency, and the second strip block 20' turns into a wet film or a water film with high transparency after encountering water vapor (see Figure 30 ).

[0237] Example 15: single-layer mulch film

[0238] See Figure 31 It is a structural schematic diagram of a multi-strip block joint area co-extrusion die of the present application, the groove cavity of the co-extrusion die is circular ring shape, and it comprises first regions 10 and second regions 20 arranged in the clockwise direction around the circumference in turn. The arc length of the two first regions is 35-40% of the circumference length of the circular ring respectively, and the two second regions are 10-15% of the circumference length of the circular ring respectively.

[0239] The first region 10 and the second region 20 are provided with a laminated lap joint area at the joint, wherein the laminated lap joint area of the first region 10 comprises a first laminated layer 11 and an outer convex widened section 12, and the laminated lap joint area of the second region 20 comprises a second laminated layer 21 and an inner convex widened section 22. The first laminated layer 11 is on the outside and the second laminated layer 21 is on the inside, and the two are laminated as part of the circular ring. The outer convex widened section 12 spans the joint of the first laminated layer 11 and the second region, and the inner convex widened section 22 spans the joint of the second laminated layer 21 and the first region.

[0240] In addition, the inner convex widened section 13 is further provided in the middle inner side of the first region.

[0241] In the present application, the "width" of the die groove cavity refers to the radial direction rather than the circumferential direction.

[0242] The widened width of the widened section area of the outer convex widened section 12 or the inner convex widened section 22 is 10-50% of the non-widened width of the first region or the second region, and the arc length (circumferential direction) of the widened section area is 2.5-20mm in the clockwise and counterclockwise directions along the circumference.

[0243] The co-extrusion die connects two extruders, one of which connects the first area and the other of which connects the second area.

[0244] Referring to Figure 32 and Figure 33 , the present application provides a multi-block adhesion area convex structure co-extrusion film, which comprises alternately arranged first blocks 10' and second blocks 20', and a lamination lap joint area is arranged between the first blocks 10' and the second blocks 20'. Wherein, the lamination lap joint area of the first block 10' comprises a first lamination 11' and an outer convex thickening section 12', and the lamination lap joint area of the second area 20' comprises a second lamination 21' and an inner along outer convex thickening section 22'. Wherein, the first lamination 11' is outside and the second lamination 21' is inside, and the two are laminated as part of the film. The outer convex thickening section 12' spans the first lamination 11' and the joint seam of the second area; the inner along outer convex thickening section 22' spans the second lamination 21' and the joint seam of the first area.

[0245] The thickness of the thickening section area of the outer convex thickening section 12' or the inner convex thickening section 22' is 10-50% of the thickness of the non-thickening area of the first area or the second area, and the length of the thickening section across the area is 5.0-40mm in each direction extending left and right of the joint line.

[0246] Wherein, the second block 20' is a transparent film block without adding or adding anti-fog drops, the first block 10' is a black opaque block adding black masterbatch, the first non-anti-fog drop (or anti-fog drop) colorless transparent block and the second black opaque block have different light transmittances.

[0247] The film is prepared by a multi-strip conveying flow channel arc groove cavity adhesion area local widening convex co-extrusion die as shown in Figure 31 .

[0248] When the mulch film is used, it is a kind of mulch film with black opaque blocks on both sides and colorless transparent blocks in the middle. The second block 20' in the middle is a transparent film without anti-fog drops or with anti-fog drops; the first block 10' is a black opaque film (see Figure 33 ).

[0249] In addition to the above-mentioned special two-color biodegradable mulch film which should be locally convexly widened, thickened and strengthened, the present application is also applicable to the local convex widening, thickening of the general biodegradable blown film machine die and mulch film, so as to realize the local convex thickening (area) strip of the mulch film to enhance the longitudinal tensile strength of the mulch film.

[0250] The above merely describes preferred embodiments of the present application, and therefore cannot limit the scope of the present application, i.e. equivalent changes and modifications to the number of blocks and the like made according to the patent scope and specification of the present application shall still fall within the scope of the present application.

Claims

1. A multi-strip block-alternating transparent anti-fog antibacterial film bag, which is a single-layer structure, or a double-layer structure of an inner layer and an outer layer, or a triple-layer structure including an inner layer, a middle layer, and an outer layer, characterized in that: The single-layer structure, or the inner layer of the double-layer structure, or the inner layer or middle layer of the three-layer structure, comprises a plurality of first anti-fog strips and a plurality of second anti-fog strips with different anti-fog time from the first anti-fog strips, wherein the first anti-fog strips and the second anti-fog strips are arranged alternately, the outer layer of the double-layer structure is a transparent film layer without adding anti-fog master batch, the inner layer and the outer layer of the three-layer structure are high transparent layers when the three-layer structure is in ABA structure and ordinary content anti-fog master batch b is added, the outer layer of the three-layer structure is a high transparent film layer without adding anti-fog master batch when the three-layer structure is in ABC three-layer structure; the strip block connection seam area of the single-layer structure is locally provided with an inner edge outward convex thickening section; the outer layer of the double-layer or three-layer structure is locally provided with or not provided with an outer edge outward convex thickening section at the strip block connection seam area of the inner layer or middle layer. ​ The second anti-fog strip comprises high pressure or low pressure PE high content anti-fog antibacterial master batch a in an amount of 8.0-10%; the master batch a comprises the following components in parts by weight: plastic carrier 21-41, inorganic powder 30-38, antioxidant 0.2-0.5, antibacterial preservative 2.0-4.0, modifier 0.8-1.2, dispersant 2.8-3.5, opening agent 1.2-1.6, and anti-fog agent 22-30.2; the inorganic powder is a compound of at least one of precipitated barium sulfate, talc powder, hydrotalcite, and diatomite powder and white carbon black, and the ratio of the total amount of at least one of precipitated barium sulfate, talc powder, hydrotalcite, and diatomite powder to the total amount of white carbon black is 1:2-1:3; during preparation, the plastic carrier, inorganic powder, antioxidant, and antibacterial preservative are measured and put into a stirrer barrel, and stirred until the material dryness is less than 1%; then the modifier and dispersant are put in for surface coating treatment; finally, the opening agent and anti-fog agent are put in, stirred uniformly, and then melted, plasticized, and extruded by a double screw granulator, and finally cooled and granulated to obtain high content anti-fog antibacterial master batch a product. The first anti-fog strip comprises ordinary content anti-fog antibacterial master batch b in an amount of 6-8% for polyolefin high pressure or low pressure PE; the master batch b comprises the following components in parts by weight: plastic carrier 72-79.5, antioxidant 0.2-0.5, antibacterial preservative 3.0-5.5, dispersant 0.6-1.0, opening agent 0.7-1.0, and anti-fog agent 16-20; during preparation, the plastic carrier, antioxidant, antibacterial preservative, dispersant, and opening agent are measured and put into a stirrer at the same time for mixing treatment for 1-3 min, then the anti-fog agent is put in for mixing treatment for 1-3 min, the material is fully and uniformly mixed by the stirrer, then melted, plasticized, and extruded by a double screw granulator, and finally cooled and granulated to obtain ordinary content anti-fog antibacterial master batch b product.

2. The multi-strip block-alternating transparent anti-fog antibacterial film pouch of claim 1, wherein: The second anti-fog strip comprises high pressure LDPE or low pressure HDPE 68-81%, high content anti-fog antibacterial master batch a 8.0-10.0% for polyolefin high pressure or low pressure PE, high pressure LDPE 5-10%, and toughening agent 6-12%.

3. The multi-strip block-alternating transparent anti-fog antibacterial film pouch of claim 1, wherein: The first anti-fog strip block comprises high-pressure LDPE or low-pressure HDPE 65-78%, polyolefin high-pressure or low-pressure PE with common content anti-fog antibacterial master batch b 6.0-8.0%, high-pressure LDPE 10-15%, toughening agent 6-12% by weight.

4. The multi-strip block-alternating transparent anti-fog antibacterial film bag according to any one of claims 1 to 3, characterized in that, The plastic carrier of the anti-fog master batch is a compound of two or more of LDPE, LLDPE, EVA and APP.

5. The multi-strip block-alternating transparent anti-fog antibacterial film pouch according to any one of claims 1 to 3, characterized in that, The anti-fog agent of the anti-fog master batch is a compound of two or more of Tween, monoglyceride, polyoxyethylene ether, stearic acid diethanolamine and polyglycerol fatty acid ester.

6. The multi-strip block-alternating transparent anti-fog antibacterial film pouch according to any one of claims 1 to 3, characterized in that, The modifier of the anti-fog master batch is one of silane coupling agent, titanate coupling agent and aluminate coupling agent; the dispersing agent is at least one of stearic acid and polyethylene wax.

7. The multi-strip block-alternating transparent anti-fog antibacterial film pouch according to any one of claims 1 to 3, characterized in that, The opening agent of the anti-fog master batch is one or both of erucic acid amide and oleic acid amide; the antioxidant is one or a compound of both of antioxidant 1010 and antioxidant 168.

8. The multi-strip block-alternating transparent anti-fog antibacterial film pouch according to any one of claims 1 to 3, characterized in that, The anti-fungus preservative of the anti-fog master batch is silver ion.

9. A multi-strip block-alternating transparent anti-fog antibacterial film bag, which is a single-layer structure, or a double-layer structure of an inner layer and an outer layer, or a triple-layer structure including an inner layer, a middle layer and an outer layer, characterized in that: The inner layer of the single-layer structure, or the inner layer of the double-layer structure, or the inner layer or the middle layer of the three-layer structure, comprises a plurality of first anti-fog strip blocks and a plurality of second anti-fog strip blocks with different anti-fog time efficiency from the first anti-fog strip blocks, wherein the first anti-fog strip blocks and the second anti-fog strip blocks are arranged alternately, the outer layer of the double-layer structure is a transparent film layer without adding anti-fog master batch, the inner and outer layers of the three-layer structure are high transparent layers when the three-layer structure is in ABA structure and adds common content anti-fog master batch b, or the outer layer of the three-layer structure is a high transparent layer without adding anti-fog master batch when the three-layer structure is in ABC structure, a lap joint area is provided between the first strip block and the second strip block, the lap joint area is that the end of the first strip block and the end of the second strip block respectively extend a lap tongue, and the two lap tongues are lap jointed inward and outward; the outer edge of the inner layer at the lap joint is provided with a non-lap joint outer convex reinforcing section covering the lap joint when the three-layer structure is in ABA structure, or is provided with an outer convex lap joint reinforcing section covering the lap joint when the three-layer structure is in ABC structure, or is not provided with an outer convex reinforcing section; The second anti-fog strip block adds 8.0-10% polyolefin high-pressure or low-pressure PE with high content anti-fog antibacterial master batch a; the master batch a comprises the following components by weight: plastic carrier 21-41, inorganic powder 30-38, antioxidant 0.2-0.5, anti-fungus preservative 2.0-4.0, modifier 0.8-1.2, dispersing agent 2.8-3.5, opening agent 1.2-1.6, anti-fog agent 22-30.2; the inorganic powder is a compound of at least one of precipitated barium sulfate, talcum powder, hydrotalcite and diatomite powder and white carbon black, and the compound ratio is that the total amount of at least one of precipitated barium sulfate, talcum powder, hydrotalcite and diatomite powder: the total amount of white carbon black is 1:2-1:3; during preparation, the plastic carrier, the inorganic powder, the antioxidant and the anti-fungus preservative are respectively measured and put into the barrel of a stirrer, and are stirred until the material dryness rate is less than 1%; then the modifier and the dispersing agent are put in for surface coating treatment; finally, the opening agent and the anti-fog agent are put in, and are uniformly stirred by a stirrer, and then are melted, plasticized and extruded by a double-screw granulator, and finally are cooled and granulated to obtain the master batch a product; The first anti-fog strip block adds 6-8% polyolefin high-pressure or low-pressure PE ordinary content anti-fog antibacterial master batch b; The master batch b includes plastic carrier 72-79.5, antioxidant 0.2-0.5, antibacterial preservative 3.0-5.5, dispersant 0.6-1.0, opening agent 0.7-1.0, and anti-fog agent 16-20 by weight; In preparation, the plastic carrier, antioxidant, antibacterial preservative, dispersant, and opening agent are simultaneously metered and put into a stirrer for mixing treatment, the mixing time is 1-3 min, then the anti-fog agent is put in for mixing treatment for 1-3 min, the material is fully and uniformly mixed by the stirrer, then it is melted, plasticized, and extruded by a double-screw granulator, and finally it is cooled and granulated to obtain the master batch b product.

10. The multi-strip block alternating transparent anti-fog antibacterial film bag according to claim 9, characterized in that, When the single-layer structure is provided, the outer convex lap joint thickening section is arranged on the inner and outer edges of the layer, or only the inner edge is provided with the outer convex lap joint thickening section, and the outer convex lap joint thickening section accounts for 10-50% of the thickness of the non-thickening section of the layer; the outer layer of the double-layer structure has a thickness of 1 / 2 to 2 / 2 of the thickness of the inner layer, the outer convex lap joint thickening section accounts for 10-50% of the thickness of the non-thickening section of the inner layer, or no local outer convex lap joint thickening section is arranged; when the three-layer structure is in the ABC structure, no outer convex thickening section is arranged, or only the inner layer outer edge is provided with the outer convex lap joint thickening section, and the outer convex lap joint thickening section accounts for 10-50% of the thickness of the non-thickening section of the inner layer; when the three-layer structure is in the ABA structure, the outer convex lap joint thickening section accounts for 10-50% of the thickness of the non-thickening section of the inner layer.

11. The multi-strip block-alternating transparent anti-fog antibacterial film pouch according to claim 10, characterized in that: The length of the outer convex lap joint thickening section of the inner layer outer edge extends 5.0-40 mm on both sides of the center line of the joint seam between the first anti-fog strip block and the second anti-fog strip block.

12. A preparation method of a multi-strip block alternating transparent anti-fog antibacterial film bag, comprising the following steps: Step one. Preparation of master batch A. Preparation of master batch a: (1) First, 21-41 plastic carriers, 30-38 inorganic powders, 0.2-0.5 antioxidants, and 2-4 antibacterial preservatives are metered and put into a stirrer barrel, and stirred until the moisture content of the material is less than 1%; (2) 0.8-1.2 modifiers and 2.8-3.5 dispersants are put in for surface coating treatment; (3) 1.2-1.6 opening agents and 22-30.2 anti-fog agents are put in for mixing treatment; (4) The mixed material after the above treatment is melted, plasticized, and extruded by a double-screw granulator, and finally cooled and granulated into a polyolefin low-pressure PE high-content anti-fog antibacterial master batch a. B. Masterbatch b preparation: by weight parts including plastic carrier 72-79.5, antioxidant 0.2~0.5, antibacterial preservative 3.0-5.5, dispersing agent 0.6-1.0, opening agent 0.7-1.0, anti-fog agent 16-20; first, the plastic carrier, antioxidant, antibacterial preservative, dispersing agent, opening agent are simultaneously metered into the mixer for mixing treatment, the mixing time is 1-3 min, then the anti-fog agent is mixed for 1-3 min, the material is fully and uniformly mixed by the mixer, then it is melted, plasticized and extruded by the double screw granulator, and finally it is air cooled and pelletized to obtain the ordinary content anti-fog antibacterial masterbatch product b for polyolefin low pressure PE; Step two. Preparation of alternating transparent film bag A. Preparation of low pressure PE anti-fog antibacterial alternating transparent film bag: (1) Prepare the first anti-fog strip block, which contains components: low pressure HDPE 65-78%, high pressure LDPE 10-15%, toughening agent 6-12%, masterbatch b prepared in step one B 6-8%; (2) Prepare the second anti-fog strip block, which contains components: low pressure HDPE 68-81%, high pressure LDPE 5-10%, toughening agent 6-12%, masterbatch a prepared in step one A 8-10%; B. Preparation of high pressure PE anti-fog antibacterial alternating transparent film bag: (1) Prepare the first anti-fog strip block, which contains components: linear high pressure LLDPE 66-79%, high pressure LDPE 10-15%, toughening agent 5-10%, opening masterbatch 2~3%, masterbatch b prepared in step one B 4-6%; (2) Prepare the second anti-fog strip block, which contains components: linear high pressure LLDPE 64-77%, high pressure LDPE 10-15%, toughening agent 5-10%, opening masterbatch 2-3%, masterbatch a prepared in step one A 6-8%; The preparation of low pressure PE anti-fog antibacterial alternating transparent film bag in step two A above and the preparation of high pressure PE anti-fog antibacterial alternating transparent film bag in step two B above are blown into film bags by co-extrusion.

13. The method for preparing a multi-strip alternating transparent anti-fog and antibacterial film bag according to claim 12, characterized in that, In step one A, the temperature of the melting and plasticizing section of the double screw granulator is 160~170℃; the temperature of the melting and plasticizing section is 145~155℃; the temperature of the melting and plasticizing over section is 135~142℃; the temperature of the plasticizing cooling section is 100~120℃; the temperature of the plasticizing cooling section is 90~100℃; the die temperature is 85~95℃.

14. The method for preparing a multi-strip alternating transparent anti-fog and antibacterial film bag according to claim 12, characterized in that, In step one B, the temperature of the melting and plasticizing section of the double screw granulator is 160~162℃; the temperature of the melting and plasticizing section is 170-172℃; the temperature of the melting and plasticizing over section is 150-155℃; the temperature of the plasticizing cooling section is 135-145℃; the temperature of the plasticizing cooling section is 129-131℃; the die temperature is 129-131℃.

15. The method for preparing a multi-strip alternating transparent anti-fog and antibacterial film bag according to claim 12, characterized in that, In step two A (1), (2), the first heating zone of the low pressure PE film bag blowing film extruder is 180℃, the second heating zone is 195℃, the third heating zone is 200℃, and the die heating zone is 210℃.

16. The method for preparing a multi-strip alternating transparent anti-fog and antibacterial film bag according to claim 12, characterized in that, Step two B (1), (2) high pressure PE film bag blowing film extruder the first heating zone 150 ℃, the second heating zone 160 ℃, the third heating zone 165 ℃, the die heating zone 160 ℃.

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