Hygienic material release film, formula and preparation method of hygienic material release film

Abstract

The invention relates to the technical field of hygienic materials, and discloses a hygienic material release film, a formula and a preparation method of the hygienic material release film. The water-based release ink comprises the following raw materials in percentage by weight: 25%-35% of silicone resin, 55%-65% of deionized water, 3%-5% of a defoaming agent and 2%-4% of a thickening agent, an intaglio printing technology is adopted, the working parameters are that the mesh number is 50-150 lines / inch, the depth of a plate roller is 20-60 microns, the printing speed is 80-120 m / min, the matched drying temperature is 50-80 DEG C, the pressure of a scraper is adjusted to be 0.2-0.8 Mpa, the depth of the plate roller is controlled to be 1-8 microns, and an ink layer is printed on a polyethylene film. The hygienic material release film has packaging protection and controllable release functions, and can be recycled at the same time.

Description

Technical Field

[0001] The present invention relates to the technical field of sanitary materials, and in particular to a sanitary material release film, a formula and a preparation method thereof. Background Art

[0002] Traditional hygiene packaging technology typically utilizes a composite structure of PE film and release paper, such as in sanitary napkins. However, the PE film itself lacks a release liner, making it difficult to adhere directly to the adhesive layer on the surface of the sanitary napkin. To achieve this, a layer of release paper is added between the PE film and the sanitary napkin as a barrier, and adhesive is used to bond them together.

[0003] This design has the following inherent flaws:

[0004] High material costs: The additional use of release paper and adhesives increases the cost of raw material procurement and composite processing; Waste of resources: Release paper only serves as a temporary isolation layer and is peeled off and discarded when consumers use sanitary products, and cannot be recycled; Environmental issues: The release paper and adhesives in the composite structure increase the proportion of non-degradable materials. At the same time, the layered structure makes recycling and processing more difficult, increasing the environmental burden.

[0005] Therefore, the existing technology urgently needs a solution that simplifies the structure, reduces unnecessary materials and optimizes environmental performance. Summary of the Invention

[0006] The technical problem solved by the present invention is to provide a method for preparing a release film for sanitary materials in order to solve the problems raised in the above-mentioned background technology in view of the defects existing in the above-mentioned prior art.

[0007] To solve the above technical problems, the technical solution adopted by the present invention is as follows: a method for preparing a release film for sanitary materials, comprising: using a biaxially oriented polyethylene film as a substrate; a water-based release ink comprising the following raw materials in the following weight proportions: 25%-35% silicone resin, 55%-65% deionized water, 3%-5% defoaming agent, and 2%-4% thickener; a gravure printing process is adopted, with the working parameters of mesh count: 50-150 lines / inch, plate roller depth: 20-60um, printing speed: 80-120m / min, and a drying temperature of 50-80°C. The ink layer is printed on the polyethylene film by adjusting the scraper pressure to 0.2-0.8Mpa and the plate roller depth to control the thickness to 1-8um.

[0008] Furthermore, the defoaming agent is a foam-breaking polymer solution that does not contain silicone; and the thickener is acrylic acid.

[0009] Furthermore, in the gravure printing process, the viscosity is adjusted to 20-30s; segmented hot air drying is adopted, the pre-drying temperature is: 50-60°C in the first stage, and the complete curing temperature is: 70-80°C in the second stage.

[0010] A method for preparing a release film for sanitary materials comprises: using a biaxially oriented polyethylene film as a substrate; an oil-based release ink comprising the following raw materials in the following weight proportions: 35%-45% acrylic resin, 45%-55% ethyl acetate, 5%-8% silicone oil, and 1%-2% dispersant; and using a gravure printing process with the following operating parameters: a mesh count of 50-150 lines / inch, a plate roller depth of 20-60 μm, a printing speed of 80-120 m / min, a drying temperature of 50-80°C, and a thickness of 1-8 μm by adjusting a scraper pressure of 0.2-0.8 MPa and a plate roller depth. The ink layer is printed on the polyethylene film.

[0011] Furthermore, the dispersant is a reactant of acrylic acid and alcohol.

[0012] Furthermore, in the gravure printing process, the viscosity is adjusted to 15-25s; segmented hot air drying is adopted, the pre-drying temperature is: 50-60°C in the first stage, and the complete curing temperature is: 70-80°C in the second stage.

[0013] A release film for sanitary materials is prepared by adopting the preparation method of the above-mentioned technical solution of water-based release ink.

[0014] A release film for sanitary materials is prepared by adopting the preparation method of the above-mentioned technical solution of oil-based release ink.

[0015] A water-based ink formula for a hygiene release film includes: the water-based release ink comprises the following raw materials in proportion by weight: 25%-35% silicone resin, 55%-65% deionized water, 3%-5% defoaming agent, and 2%-4% thickener.

[0016] A formula of oil-based ink for release film of sanitary materials, comprising: the oil-based release ink comprises the following raw materials in weight proportions: acrylic resin 35%-45%, ethyl acetate 45%-55%, silicone oil 5%-8%, dispersant 1%-2%

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] Simplified structure and reduced costs: By directly coating a release layer (water-based or oil-based ink) on polyethylene film, packaging protection and release functions are achieved, replacing the traditional "PET + release paper + adhesive layer" structure. This eliminates the release paper and adhesive required in traditional composite structures, reducing the number of raw materials and composite processing steps. This eliminates the cost of purchasing release paper and the adhesive coating process, reducing overall costs.

[0019] Economical and environmentally friendly: The single polyethylene substrate structure is easier to recycle and no additional waste is generated, which meets the requirements of the circular economy and achieves the goal of green environmental protection. DETAILED DESCRIPTION

[0020] In view of the technical problems described in the background art, a method for preparing a release film for sanitary materials is provided, comprising: using a biaxially oriented polyethylene film as a substrate; a water-based release ink comprising the following raw materials in the following weight proportions: 25%-35% silicone resin, 55%-65% deionized water, 3%-5% defoamer, and 2%-4% thickener; using a gravure printing process with operating parameters of 50-150 lines / inch, 20-60 μm plate roller depth, and 80-120 m / min printing speed, a drying temperature of 50-80°C, and printing an ink layer on the polyethylene film by adjusting the scraper pressure to 0.2-0.8 MPa and the plate roller depth to control the thickness to 1-8 μm.

[0021] Preferably, the defoaming agent is a foam-breaking polymer solution that does not contain silicone; and the thickener is acrylic acid.

[0022] Preferably, in the gravure printing process, the viscosity is adjusted to 20-30s (Zion #2 cup, 25°C); segmented hot air drying is adopted, the pre-drying temperature is: the first stage temperature is 50-60°C, and the complete curing temperature is: the second stage temperature is 70-80°C.

[0023] Example 1: Preparation of a release film for sanitary products with water-based release ink. The release film for sanitary products can be used for packaging of disposable sanitary products such as sanitary napkins, panty liners, and diapers, as well as for industrial use.

[0024] The raw materials used in water-based release inks are as follows: 30% silicone resin, 62% deionized water, 4% defoamer, and 4% thickener, by weight. The silicone resin provides release properties, the defoamer prevents printing bubbles, and the thickener adjusts leveling.

[0025] Use biaxially oriented polyethylene film as the substrate, with a thickness ranging from 20-50 μm, preferably 30-40 μm. The substrate must meet the following performance requirements: Mechanical properties: Tensile strength ≥ 2 N / inch, elongation at break ≥ 80%, ensuring no damage during use. Surface properties: Surface tension ≥ 40 mN / m to improve ink adhesion (refer to ASTM D2578). Environmental friendliness: RoHS compliant, free of heavy metals and harmful plasticizers.

[0026] Using a gravure printing process, the ink layer thickness is controlled at 1-8μm, the plate depth is controlled at 20-60μm, the printing speed is controlled at 80-120m / min, the drying temperature is controlled at 50-80°C, and the printing pressure is controlled at 0.2-0.8MPa. Viscosity control: The water-based ink viscosity is adjusted to 20-30s (Zai En #2 cup, 25°C). This can be adjusted according to the actual situation to coordinately control adhesion and release forces. A staged hot air drying method is used, with the pre-drying temperature in the first stage at 50-60°C and the full curing temperature in the second stage at 70-80°C.

[0027] The release force test of the printed hygiene release film was carried out.

[0028] The test method is: refer to the FINAT FTM 10 standard and use a universal material testing machine to test the release force.

[0029] Test conditions: peel angle 180°, peel speed 300mm / min, test width 1inch.

[0030] Target range: 0.4-2.5N / inch (adjusted according to the type of sanitary napkin adhesive).

[0031] In the above technical solution, for every 5% increase in the silicone resin content, the release force decreases by 0.1-0.15N / 25mm (adhesion needs to be balanced), and for every 10μm increase in the plate roller depth, the release force decreases by 0.5-1N / 25mm (the target value is adjusted through thickness compensation). Therefore, the proportions of resin, solvent, and additives can be adjusted according to the release force of the desired sanitary release film.

[0032] Example 2: A method for preparing a release film for sanitary materials, comprising: using a biaxially oriented polyethylene film as a substrate; an oily release ink comprising the following raw materials in the following weight proportions: 35%-45% acrylic resin, 45%-55% ethyl acetate, 5%-8% silicone oil, and 1%-2% dispersant; using a gravure printing process with the following working parameters: mesh count: 50-150 lines / inch, plate roller depth: 20-60 μm, printing speed: 80-120 m / min, a drying temperature of 50-80°C, and printing an ink layer on the polyethylene film by adjusting the scraper pressure to 0.2-0.8 MPa and the plate roller depth to control the thickness to 1-8 μm.

[0033] Preferably, the dispersant is a reactant of acrylic acid and alcohol.

[0034] Preferably, in the gravure printing process, the viscosity is adjusted to 15-25s; segmented hot air drying is adopted, the pre-drying temperature is: 50-60°C in the first stage, and the complete curing temperature is: 70-80°C in the second stage.

[0035] The raw materials used in oil-based release inks are: 40% acrylic resin, 52% ethyl acetate, 6% silicone oil, and 2% dispersant by weight. The acrylic resin enhances the ink's adhesion to the polyethylene film, the silicone oil adjusts the release force, and the dispersant improves uniformity.

[0036] Use biaxially oriented polyethylene film as the substrate, with a thickness ranging from 20-50 μm, preferably 30-40 μm. The substrate must meet the following performance requirements: Mechanical properties: Tensile strength ≥ 2 N / inch, elongation at break ≥ 80%, ensuring no damage during use. Surface properties: Surface tension ≥ 40 mN / m to improve ink adhesion (refer to ASTM D2578). Environmental friendliness: RoHS compliant, free of heavy metals and harmful plasticizers.

[0037] Using a gravure printing process, the thickness of the printed ink layer is controlled at 1-8μm, the depth of the printing plate is controlled at 20-60μm, the printing speed is controlled at 80-120m / min, the drying temperature is controlled at 50-80°C, and the printing pressure is controlled at 0.2-0.8Mpa. The viscosity of the oil-based ink is controlled at 15-25S, which can be adjusted according to the actual situation to coordinate the adhesion and release forces. The pre-drying temperature is 50-60°C in the first stage and the complete curing temperature is 70-80°C in the second stage.

[0038] The release force test of the printed hygiene release film was carried out.

[0039] The test method is: refer to the FINAT FTM 10 standard and use a universal material testing machine to test the release force.

[0040] Test conditions: peel angle 180°, peel speed 300mm / min, test width 1inch.

[0041] Target range: 0.4-2.5N / inch (adjusted according to the type of sanitary napkin adhesive).

[0042] In the above technical solution, for every 5% increase in the acrylic resin content, the release force decreases by 0.1-0.15N / 25mm (adhesion needs to be balanced), and for every 10μm increase in the plate roller depth, the release force decreases by 0.5-1N / 25mm (the target value is adjusted through thickness compensation). Therefore, the proportion of resin, solvent, and additives can be adjusted according to the release force of the desired sanitary release film.

[0043] The above does not limit the technical scope of the present invention. Any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for preparing a release film for sanitary materials, characterized in that: include: Biaxially oriented polyethylene film is used as the base material; Water-based release ink includes the following raw materials in the following weight proportions: silicone resin 25%-35%, deionized water 55%-65%, defoaming agent 3%-5%, thickener 2%-4%; The gravure printing process is adopted, and the working parameters are mesh count: 50-150 lines / inch, plate roller depth: 20-60um, printing speed: 80-120m / min, drying temperature 50-80℃, and the ink layer is printed on the polyethylene film by adjusting the scraper pressure at 0.2-0.8Mpa and the plate roller depth to control the thickness of 1-8um.

2. The method for preparing a release film for sanitary materials according to claim 1, wherein: The defoamer is a foam-breaking polymer solution that does not contain silicone; the thickener is acrylic acid.

3. The method for preparing a release film for sanitary materials according to claim 1, wherein: In the gravure printing process, the viscosity is adjusted to 20-30s; segmented hot air drying is adopted, the pre-drying temperature is: 50-60°C in the first segment, and the complete curing temperature is: 70-80°C in the second segment.

4. A method for preparing a release film for sanitary materials, characterized in that: include: Biaxially oriented polyethylene film is used as the base material; Oil-based release ink includes the following raw materials in the following weight proportions: acrylic resin 35%-45%, ethyl acetate 45%-55%, silicone oil 5%-8%, dispersant 1%-2%; The gravure printing process is adopted, and the working parameters are mesh count: 50-150 lines / inch, plate roller depth: 20-60um, printing speed: 80-120m / min, drying temperature 50-80℃, and the ink layer is printed on the polyethylene film by adjusting the scraper pressure at 0.2-0.8Mpa and the plate roller depth to control the thickness of 1-8um.

5. The method for preparing a release film for sanitary materials according to claim 4, wherein: The dispersant is a reactant of acrylic acid and alcohol.

6. The method for preparing a release film for sanitary materials according to claim 4, wherein: In the gravure printing process, the viscosity is adjusted to 15-25s; segmented hot air drying is adopted, the pre-drying temperature is: 50-60°C in the first segment, and the complete curing temperature is: 70-80°C in the second segment.

7. A release film for hygiene materials, characterized in that: The method is prepared by any one of claims 1 to 3.

8. A release film for hygiene materials, characterized in that: The method is prepared by any one of claims 4 to 6.

9. A water-based ink formula for a release film for medical materials, characterized in that: include: The water-based release ink includes the following raw materials in proportion by weight: 25%-35% silicone resin, 55%-65% deionized water, 3%-5% defoaming agent, and 2%-4% thickener.

10. A formula of oil-based ink for a release film of a hygiene material, characterized in that: include: The oil-based release ink includes the following raw materials in proportion by weight: 35%-45% acrylic resin, 45%-55% ethyl acetate, 5%-8% silicone oil, and 1%-2% dispersant.