Easily-tearable antibacterial functional release paper

Abstract

The utility model relates to the related technical field of isolation paper, especially easy to tear antibacterial functional isolation paper, adopts asymmetric three -layer composite structure, from top to bottom is upper layer, middle layer and lower layer in proper order, the surface of upper layer is coated with chitosan antibacterial coating, the middle layer is the polylactic acid microporous membrane of loading nano zinc oxide, the back of lower layer is provided with laser pre -indentation, the utility model discloses through lower layer pre -indentation and middle layer microporous membrane synergy realizes the guided tear, has solved the contradiction of easy to tear and overall strength, and through the surface layer contact sterilization, middle layer slow -release sterilization and physical barrier combination, realized multiple synergistic long -term antibacterial, and the product has the advantages of accurate easy to tear, efficient antibacterial, and is suitable for the field of high sanitary requirement such as medical dressing, food packaging.

Description

Technical Field

[0001] This utility model relates to the technical field of release paper, and in particular to an easy-tear antibacterial functional release paper. Background Technology

[0002] Release paper is widely used in medical dressings, food packaging, pressure-sensitive tapes and other fields. Its main function is to protect the surface of the object being applied from contamination and adhesion, and to allow it to be easily removed when needed. To achieve easy tearing, common methods include pre-cut micro-perforations or mechanical creasing. However, pre-cut micro-perforations can damage the integrity of the paper, which may allow liquids or bacteria to pass through or cause accidental breakage before use. Traditional mechanical creasing is not easy to tear if the depth is insufficient, and if the depth is too deep, it will also seriously weaken the paper strength and make it easy to break at the creasing point during winding and storage.

[0003] To address the aforementioned issues, an easy-tear antibacterial functional release paper is proposed. Utility Model Content

[0004] The purpose of this invention is to provide an easy-tear antibacterial functional release paper to address the problems of existing easy-tear antibacterial functional release papers mentioned in the background section.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an easy-tear antibacterial functional release paper, comprising an upper layer, a middle layer, and a lower layer stacked sequentially from top to bottom; The upper layer has an antibacterial coating on the side facing the object to be isolated. The lower layer has a pre-indentation on the side facing away from the middle layer.

[0006] Preferably, the upper layer is a high-density, high-smoothness thin sheet of paper, and is food-grade parchment paper.

[0007] Preferably, the antibacterial coating is a chitosan coating.

[0008] Preferably, the intermediate layer is a biodegradable polymer film, and is a polylactic acid microporous membrane.

[0009] Preferably, the intermediate polylactic acid microporous membrane contains nano-zinc oxide antibacterial agent dispersed within it.

[0010] Preferably, the lower layer is kraft paper with a basis weight of 30-80 g / m².

[0011] Preferably, the pre-indentation is formed by laser indentation to create a dotted line structure.

[0012] Preferably, the upper layer, middle layer and lower layer are bonded together by a water-based polyurethane adhesive.

[0013] Compared with the prior art, the beneficial effects of this utility model are: By setting a pre-indentation in the lower layer and using a polymer microporous membrane in the middle layer, a guided tear is created. When the user applies force from the lower layer, the tearing force will preferentially start from the stress concentration point of the pre-indentation and quickly spread along the weak path of the microporous membrane in the middle layer, eventually completing a neat tear. This ensures that easy straight tearing can be achieved at any desired location, while avoiding the barrier failure and accidental breakage problems caused by traditional pre-cut micropores, thus solving the contradiction between tearability and overall strength.

[0014] The upper layer is responsible for contact protection and antibacterial properties, the lower layer is responsible for guiding tearing, and the middle layer provides easy tearing guidance and an antibacterial barrier. This structure ensures that the side of the product that comes into contact with the protected object is smooth and antibacterial during use, while the side facing the user is easy to operate and tear. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model; Figure 2 This is a schematic diagram of the disassembled structure of this utility model.

[0016] In the diagram: 1. Top layer; 2. Antibacterial layer; 3. Middle layer; 4. Bottom layer; 5. Pre-indentation. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0018] Example like Figure 1 , 2 As shown, it includes an upper layer 1, a middle layer 3 and a lower layer 4 stacked from top to bottom. The side of the upper layer 1 facing the object to be isolated is coated with an antibacterial coating 2, and the side of the lower layer 4 facing away from the middle layer 3 is provided with a pre-indentation 5.

[0019] It should be noted that, in this embodiment, the upper layer 1 uses 40g / m³. 2 The food-grade parchment paper used has a high density, smooth surface, and dense fiber structure, effectively preventing the penetration of adhesives and liquids. The antibacterial layer 2 is applied via a roll coating process, where a 1.5% (by weight) chitosan-acetic acid aqueous solution is coated onto the smooth side of the parchment paper, the side facing the object to be isolated. This is followed by drying in an 80°C hot air tunnel, forming a transparent, dense, and robust chitosan antibacterial coating 2. The intermediate layer 3 is a 20μm thick polylactic acid microporous membrane, prepared using a uniaxial stretching process. This membrane has uniformly distributed micron-sized pores. During PLA granulation, 1% (by weight) of nano-zinc oxide antibacterial agent is pre-mixed in to ensure uniform dispersion within the membrane. The lower layer 4 uses 60g / m³...2 Kraft paper, which has certain mechanical strength and low cost, is used to indent the outer surface of the lower layer 4, i.e., the side facing away from the middle layer, using a CO2 laser marking machine. The indentation depth is controlled at 1 / 3-1 / 2 of the paper thickness, so that the pre-indentation 5 forms a continuous dotted line structure with a dotted line interval of 5mm. Finally, the above-treated upper layer 1, with the side coated with antibacterial coating facing outwards, and the middle and lower layers with the pre-indentation side facing outwards, are dry-laminated on a three-roll laminator using water-based polyurethane adhesive. After curing, an integrated release paper is formed.

[0020] Preparation steps: S1: The upper layer 1 parchment paper is coated and dried to form an antibacterial coating 2.

[0021] S2: The lower layer 4 kraft paper is pre-indented by laser treatment.

[0022] S3: On the laminating machine, unwind the following layers in sequence: upper layer 1 with antibacterial side facing up, middle layer 3, and lower layer 4 with indentation side facing down. Apply water-based polyurethane adhesive evenly to both sides of the middle layer 3 PLA film through the coating unit, and press the upper layer 1, middle layer 3, and lower layer 4 together through the pressing roller.

[0023] S4: The final pressed product enters the drying tunnel for drying, and is then rolled up and cut to obtain the finished product.

[0024] Working principle of this utility model: Refer to the instruction manual appendix Figure 1 , 2 The laser pre-indentation 5 on the lower layer 4 kraft paper destroys the fiber structure at the indentation point through laser energy, making its strength much lower than the surrounding area. The micropores in the PLA microporous membrane form stress concentration points in the tensile direction, and its own breaking strength is also lower than that of the paper. When the user needs to tear the release paper, force is applied from the lower layer 4 with the pre-indentation 5. The stress is first highly concentrated at the indentation 5, causing the kraft paper layer to break first from this point. The crack extends downward and penetrates the entire kraft paper layer. When the crack encounters the PLA microporous membrane in the middle, it will easily extend along the preset micropore path, making the film easier to tear. Finally, the crack is transmitted to the high-strength parchment of the upper layer 1. Since the support layer below it has been torn, the parchment is also torn under the stress at the crack tip. This asymmetrical structure, with the lower layer 4 guiding, the middle layer weakening, and the upper layer 1 following, enables tearing to be completed with very little force.

[0025] Chitosan molecules are positively charged, while bacterial cell membranes are usually negatively charged. When bacteria come into contact with the chitosan coating on the upper layer 1, the two are firmly bound together through electrostatic adsorption. Chitosan then penetrates the cell wall and may chelate metal ions necessary for cell growth, disrupting normal metabolism and ultimately causing leakage of bacterial cell contents and death, thus achieving an active antibacterial effect. The nano-zinc oxide dispersed in the PLA membrane can generate reactive oxygen species under light or humid conditions. These highly active substances can directly oxidize and damage bacterial proteins, lipids, and DNA, providing a continuous and long-lasting antibacterial environment. Even if a few bacteria penetrate the upper layer 1, they will be eliminated in this layer. The high-density parchment paper and PLA membrane itself constitute a physical barrier that can block the permeation of most bacteria and liquids, physically cutting off the contamination path. The easy-tear function is mainly achieved through the lower layer 4, ensuring the integrity and high strength of the contact surface of the upper layer 1 and avoiding the risk of accidental damage during use due to the easy tearing of the overall material.

[0026] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An easy-tear antibacterial functional release paper, characterized in that: It includes an upper layer (1), a middle layer (3) and a lower layer (4) that are stacked and combined from top to bottom. The upper layer (1) is coated with an antibacterial coating (2) on the side facing the object to be isolated. The lower layer (4) has a pre-indentation (5) on the side facing away from the middle layer (3).

2. The easy-tear antibacterial functional release paper according to claim 1, characterized in that: The upper layer (1) is a high-density, high-smoothness thin paper, and is food-grade parchment paper.

3. The easy-tear antibacterial functional release paper according to claim 1, characterized in that: The antibacterial coating (2) is a chitosan coating.

4. The easy-tear antibacterial functional release paper according to claim 1, characterized in that: The intermediate layer (3) is a biodegradable polymer film and is a polylactic acid microporous membrane.

5. The easy-tear antibacterial functional release paper according to claim 1, characterized in that: The intermediate layer (3) contains nano-zinc oxide antibacterial agent dispersed in the polylactic acid microporous membrane.

6. The easy-tear antibacterial functional release paper according to claim 1, characterized in that: The lower layer (4) is kraft paper with a basis weight of 30-80 g / m².

7. The easy-tear antibacterial functional release paper according to claim 1, characterized in that: The pre-indentation (5) is a dashed line structure formed by laser indentation.

8. The easy-tear antibacterial functional release paper according to claim 1, characterized in that: The upper layer (1), the middle layer (3) and the lower layer (4) are bonded together by water-based polyurethane adhesive.

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