阅读说明：本技术 一种用于冷藏保鲜的耐穿刺复合收缩膜 (Puncture-resistant composite shrink film for refrigeration and preservation ) 是由 钱吉鸣 顾静 杨伟 于 2019-10-22 设计创作，主要内容包括：本发明涉及一种用于冷藏保鲜的耐穿刺复合收缩膜,从上至下依次包括基材层、粘合层和收缩层；所述基材层为BOPA薄膜,所述粘合层为无溶剂胶黏剂层,所述收缩层为多层共挤薄膜,通过多层共挤工艺制得；其中所述BOPA薄膜厚度为15μm～25μm,BOPA薄膜的收缩率为15～20％；所述多层共挤薄膜的热收缩率为15％～25％；所述多层共挤薄膜为6层膜结构,厚度为40μm～100μm,具体结构为第一PE层/第一EVA层/PVDC层/TIE层/第二PE层/第二EVA层,多层共挤薄膜的各层厚度分别为：第一PE层为5μm～10μm；第一EVA层为11μm～30μm；PVDC层为3μm～5μm；TIE层为2μm～5μm；第二PE层为8μm～20μm；第二EVA层为11μm～30μm。本发明的复合收缩膜具备较高的耐穿刺性能和阻气阻水性能,适于包装带刺或带骨的海鲜产品,且在冷藏温度为0～4℃时,可以将保鲜期延长至40～60天。(The invention relates to a puncture-resistant composite shrink film for refrigeration and fresh keeping, which sequentially comprises a base material layer, a bonding layer and a shrink layer from top to bottom; the base material layer is a BOPA film, the bonding layer is a solvent-free adhesive layer, and the shrinkage layer is a multilayer co-extrusion film and is prepared by a multilayer co-extrusion process; wherein the thickness of the BOPA film is 15-25 μm, and the shrinkage rate of the BOPA film is 15-20%; the heat shrinkage rate of the multilayer co-extruded film is 15-25%; the multilayer co-extruded film is of a 6-layer film structure, the thickness of the multilayer co-extruded film is 40-100 microns, the specific structure is a first PE layer/a first EVA layer/a PVDC layer/a TIE layer/a second PE layer/a second EVA layer, and the thicknesses of the layers of the multilayer co-extruded film are respectively as follows: the first PE layer is 5-10 μm; the first EVA layer is 11-30 μm; the PVDC layer is 3-5 μm; the TIE layer is 2-5 μm; the second PE layer is 8-20 μm; the second EVA layer is 11-30 μm. The composite shrink film has high puncture resistance and gas and water resistance, is suitable for packaging the seafood with thorns or bones, and can prolong the preservation period to 40-60 days when the refrigeration temperature is 0-4 ℃.)

1. A puncture-resistant composite shrink film for refrigeration and fresh keeping is characterized by sequentially comprising a base material layer, a bonding layer and a shrink layer from top to bottom; the base material layer is a BOPA film, the bonding layer is a solvent-free adhesive layer, and the shrinkage layer is a multilayer co-extrusion film and is prepared by a multilayer co-extrusion process; wherein the thickness of the BOPA film is 15-25 μm, and the shrinkage rate of the BOPA film is 15-20%; the heat shrinkage rate of the multilayer co-extruded film is 15-25%;

the multilayer co-extruded film is of a 6-layer film structure, the thickness of the multilayer co-extruded film is 40-100 microns, the specific structure is a first PE layer/a first EVA layer/a PVDC layer/a TIE layer/a second PE layer/a second EVA layer, and the thicknesses of the layers of the multilayer co-extruded film are respectively as follows: the first PE layer is 5-10 μm; the first EVA layer is 11-30 μm; the PVDC layer is 3-5 μm; the TIE layer is 2-5 μm; the second PE layer is 8-20 μm; the second EVA layer is 11-30 μm.

2. The puncture-resistant composite shrink film for cold preservation according to claim 1, wherein the thickness of the adhesive layer is 2 μm to 4 μm.

3. The puncture-resistant composite shrink film for cold preservation according to claim 1, wherein the solvent-free adhesive layer is a two-component polyurethane adhesive.

4. The puncture-resistant composite shrink film for cold preservation according to claim 1, wherein an inner print layer is further provided between the substrate layer and the adhesive layer.

5. A multilayer coextrusion process for preparing the multilayer coextrusion film as claimed in claim 1, which is characterized by comprising the following specific steps: respectively putting raw material particles of PE, EVA, PVDC, TIE, PE and EVA into an extruder, and forming a pipe blank through a die head, wherein the pipe blank comprises the PE, the EVA, the PVDC, the TIE, the PE and the EVA from outside to inside in sequence; the tube blank is dragged into a high-energy electron beam crosslinking device through a rubber roller to carry out crosslinking treatment; then, heating the cross-linked pipe blank by a hot water bath device; after heating, drying the water on the surface of the pipe blank by a drying device; the dried pipe blank enters an inflation die head, and the pipe blank is inflated through an automatic inflation technology, wherein the inflation ratio is 1.2-1.5; forming a double-layer film by the blown film bubble through a herringbone clamping plate, carrying out corona treatment on a first PE layer on the outer surface of the double-layer film, planing edges and rolling to obtain a multi-layer co-extruded film; the heat shrinkage rate of the multilayer co-extruded film is 15-25%.

6. The multilayer co-extrusion process of the multilayer co-extruded film according to claim 5, wherein the water bath heating temperature of the hot water bath device is 80-90 ℃ and the heating time is 50 seconds.

7. The multilayer coextrusion process for multilayer coextrusion films according to claim 6, wherein the blow-up ratio is 1.3.

8. A composite method for preparing the puncture-resistant composite shrink film for refrigeration and fresh keeping of claims 1-4 is characterized by comprising the following steps: coating a solvent-free adhesive on the upper surface of the BOPA to form an adhesive layer, compounding the first PE layer of the multilayer co-extruded film right opposite to the adhesive layer to prepare a composite shrink film, curing the composite shrink film at high temperature, and then winding.

9. The method for compounding the puncture-resistant composite shrink film for cold preservation according to claim 8, wherein an inner print layer is formed by performing inner print printing on the upper surface of the BOPA before the solvent-free adhesive is coated; after the inner printing layer is formed, coating a solvent-free adhesive on the surface of the inner printing layer to form an adhesive layer; the thickness of the adhesive layer is 2-3 μm.

10. The method for compounding the puncture-resistant composite shrink film for refrigeration and fresh keeping according to any one of claims 8 or 9, wherein the curing temperature is 40 ℃ to 45 ℃ and the curing time is 48 to 24 hours.

Technical Field

The invention relates to the technical field of packaging films, in particular to a puncture-resistant composite shrink film for refrigeration and fresh keeping.

Background

The applicant develops a series of shrink films before, for example, a Chinese patent with publication number CN103042791B discloses a multilayer co-extrusion anticoagulation high-resistance heat-insulation shrink film and a preparation method thereof, and a Chinese patent with publication number CN106739356B discloses a multilayer co-extrusion shrink film and a production process thereof, but the free shrinkage rate of the shrink film during storage is up to 11%, and the shrink film can be packaged only by surface printing, so that ink is easy to fall off in the transportation process.

In order to solve the problems, the applicant proposes a puncture-resistant composite shrink film for refrigeration and fresh keeping.

Disclosure of Invention

The first purpose of the invention is to provide a puncture-resistant composite shrink film for refrigeration and fresh keeping, and the second purpose of the invention is to provide a multilayer co-extrusion process for preparing a multilayer co-extrusion film; the second purpose of the invention is to provide a compounding method of the puncture-resistant composite shrink film for refrigeration and fresh keeping. The puncture-resistant composite shrink film for refrigeration and preservation disclosed by the invention is low in shrinkage rate, can be packaged by means of inner printing and is high in ink durability.

In order to achieve the above object, a first aspect of the present invention provides a puncture-resistant composite shrink film for cold storage and fresh keeping, which is characterized by comprising, from top to bottom, a substrate layer, an adhesive layer and a shrink layer; the base material layer is a BOPA film, the bonding layer is a solvent-free adhesive layer, and the shrinkage layer is a multilayer co-extrusion film and is prepared by a multilayer co-extrusion process; wherein the thickness of the BOPA film is 15-25 μm, and the shrinkage rate of the BOPA film is 15-20%; the heat shrinkage rate of the multilayer co-extruded film is 15-25%;

the multilayer co-extruded film is of a 6-layer film structure, the thickness of the multilayer co-extruded film is 40-100 microns, the specific structure is a first PE layer/a first EVA layer/a PVDC layer/a TIE layer/a second PE layer/a second EVA layer, and the thicknesses of the layers of the multilayer co-extruded film are respectively as follows: the first PE layer is 5-10 μm; the first EVA layer is 11-30 μm; the PVDC layer is 3-5 μm; the TIE layer is 2-5 μm; the second PE layer is 8-20 μm; the second EVA layer is 11-30 μm.

Wherein the BOPA film is a biaxially oriented polyamide film produced by Xiamen Long Plastic industry Co.Ltd; the first PE layer is made of 1002AY of ExxonMobil; the first EVA layer is made of 3165 of DUPONT; the PVDC layer is made of XUS32019 of DOW; the TIE layer is prepared from 41E687 of DUPONT; the second PE layer is made of 5500G of DOW; the second EVA layer is made of DUPONT 3165.

Preferably, the solvent-free adhesive is a two-component polyurethane adhesive produced by Nantong high-union new materials Co.

Preferably, the thickness of the adhesive layer is 2 to 4 μm.

Preferably, an inner printing layer is further arranged between the base material layer and the bonding layer, and the thickness of the inner printing layer is 1-2 microns.

The second aspect of the invention provides a multilayer co-extrusion process for preparing a multilayer co-extruded film, which comprises the following specific steps: respectively putting raw material particles of PE, EVA, PVDC, TIE, PE and EVA into an extruder, and forming a pipe blank through a die head, wherein the pipe blank comprises the PE, the EVA, the PVDC, the TIE, the PE and the EVA from outside to inside in sequence; the tube blank is dragged into a high-energy electron beam crosslinking device through a rubber roller to carry out crosslinking treatment; then, heating the cross-linked pipe blank by a hot water bath device; after heating, drying the water on the surface of the pipe blank by a drying device; the dried pipe blank enters an inflation die head, and the pipe blank is inflated through an automatic inflation technology, wherein the inflation ratio is 1.2-1.5; forming a double-layer film by the blown film bubble through a herringbone clamping plate, carrying out corona treatment on a first PE layer on the outer surface of the double-layer film, planing edges and rolling to obtain a multi-layer co-extruded film; the heat shrinkage rate of the multilayer co-extruded film is 15-25%.

Preferably, the water bath heating temperature of the hot water bath device is 80-90 ℃, and the heating time is 50 seconds.

Further, the blow-up ratio is 1.3.

The third aspect of the invention provides a compounding method of a puncture-resistant composite shrink film for refrigeration and fresh keeping, which comprises the following specific steps: coating a solvent-free adhesive on the upper surface of the BOPA to form an adhesive layer, compounding the first PE layer of the multilayer co-extruded film right opposite to the adhesive layer to prepare a composite shrink film, curing the composite shrink film at high temperature, and then winding.

The first PE layer of the multilayer co-extruded film is subjected to corona treatment, so that the composite strength of the BOPA and the multilayer co-extruded film can be enhanced, and the peeling strength of the composite shrink film is improved; the substrate layer selects BOPA, and the puncture resistance of the composite shrink film is greatly improved.

Preferably, before the solvent-free adhesive is coated, performing inner printing on the upper surface of the BOPA, and forming an inner printing layer; after the inner printing layer is formed, coating a solvent-free adhesive on the surface of the inner printing layer to form an adhesive layer; the thickness of the adhesive layer is 2-3 μm.

Preferably, the curing temperature is 40-45 ℃, and the curing time is 48-24 hours.

Compared with the prior art, the puncture-resistant composite shrink film for refrigeration and fresh keeping has the following advantages:

(1) according to the invention, the multi-layer co-extrusion process of the multi-layer co-extrusion film is controlled, so that the shrinkage rate of the multi-layer co-extrusion film is reduced and is 15-25%, and thus the synchronous shrinkage of the BOPA and the multi-layer co-extrusion film can be realized;

(2) according to the compounding method of the puncture-resistant composite shrink film for refrigeration and fresh keeping, the solvent-free adhesive is completely reacted during the curing by adjusting the curing conditions, so that the peel strength of the composite shrink film is controlled to be more than 5N/15mm, and the composite shrink film does not wrinkle or delaminate during the shrinkage;

(3) the puncture-resistant composite shrink film for refrigeration and preservation has high puncture resistance and gas and water resistance, is suitable for packaging barbed or boned seafood products, and can prolong the preservation period to 40-60 days at the refrigeration temperature of 0-4 ℃.

Detailed Description

The present invention will be further described with reference to the following embodiments. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, and the protection scope of the present invention is not limited thereby.

Abbreviations in the present invention are as follows:

BOPA: biaxially stretching a nylon film;

PE: polyethylene;

EVA: vinyl acetate-ethylene copolymers;

PVDC: polyvinylidene chloride;

TIE: maleic anhydride-modified polyethylene.

The present invention will be further described with reference to the following specific examples.