A method for producing an interlayer separation film

Abstract

The application discloses a preparation method of an interlayer separation film, which comprises the following steps: combining a sealing layer with a bottom film to form a supporting composite layer, cutting the supporting composite layer to form a drinking opening on the sealing layer, wherein the bottom film is made of a material with a tensile strength of 50-350 MPa and an elongation of 90-500%, combining the sealing layer on the supporting composite layer with a barrier layer through a colloid, curing the colloid between the barrier layer and the sealing layer to form a peeling layer, wherein the peeling strength between the bottom film and the sealing layer on the supporting composite layer is smaller than the peeling strength between the barrier layer and the sealing layer, and removing the bottom film to form the interlayer separation film. The interlayer separation film prepared by the method has good sealing performance and easy peelability, and has a high yield.

Description

Technical Field

[0001] This invention relates to the field of packaging, and more specifically to a method for preparing an interlayer separation membrane. Background Technology

[0002] Conventional lid films are typically made by combining a barrier layer and a heat-sealing layer, with an overall thickness of less than 200μm. In use, a straw is usually inserted. This method not only requires a straw, but also often results in the straw being damaged and unable to be inserted into the cup if the lid film is too rigid or the straw is improperly positioned, making operation very inconvenient. Furthermore, the use of straws is extremely environmentally unfriendly.

[0003] To overcome the problems of environmentally unfriendly use of existing straws and the inconvenience caused by damage when straws are inserted into the lid, an interlayer separation membrane with at least three layers has been developed. From the outside to the inside, the interlayer separation membrane consists of a barrier layer, a release layer, and a heat-sealing layer. A low-strength adhesive is used as the release layer, which is combined with the barrier layer and the heat-sealing layer. The heat-sealing layer has a drinking opening. In use, simply peel off the barrier layer, leaving the heat-sealing layer on the container. Drinking can be done through the pre-drinking opening on the heat-sealing layer without a straw, thus eliminating the problem of straw damage when inserted into the lid.

[0004] However, in the preparation of this interlayer separation membrane, a drinking opening needs to be created on the heat-sealing layer, which requires cutting to form an opening. Several problems arise during the actual preparation process, resulting in a low yield. Specifically, in cutting the drinking opening on the heat-sealing layer, a cutting tool is used to create the opening. Because the heat-sealing layer is relatively soft, has low hardness, and high elongation, directly cutting the opening with a blade before laminating it with the barrier layer causes significant deformation of the heat-sealing layer. This makes it impossible to fix the drinking opening position on the prepared interlayer separation membrane, resulting in a low yield of the final interlayer separation membrane. If the method involves first laminating the barrier layer and heat-sealing layer, and then reverse-cutting the cap film to create an opening in the heat-sealing layer to form the drinking spout, precise control of the cutting head is required. The reason is that the barrier layer, made of Al material with good barrier properties, has relatively low toughness and is prone to stress cracking under pressure. Therefore, if the cutting head cuts too shallowly, while it won't damage the barrier layer, it won't create an opening in the heat-sealing layer. Conversely, if the cutting head cuts too deeply, it will damage the barrier layer, causing stress cracking and compromising the sealing performance of the interlayer separation membrane, thus failing to achieve a seal. Existing equipment cannot precisely control the cutting head's accuracy, thus failing to achieve the goal of effectively creating an opening in the heat-sealing layer without damaging the barrier layer. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is that the interlayer separation membrane disclosed in the prior art has a low yield rate when prepared by conventional methods; and thus provides an interlayer separation membrane preparation method that can more effectively prepare qualified interlayer separation membranes.

[0006] Therefore, the present invention provides the following technical solution:

[0007] A method for preparing an interlayer separation membrane, comprising:

[0008] The sealing layer and the bottom film are combined to form a supporting composite layer. The supporting composite layer is cut to form a drinking opening on the sealing layer. The bottom film is made of a material with a compressive strength between 50MPa and 350MPa and an elongation between 90% and 500%.

[0009] The sealing layer on the support composite layer is bonded to the barrier layer with an colloid. The colloid is cured between the barrier layer and the sealing layer to form a release layer. The peel strength between the bottom film and the sealing layer on the support composite layer is less than the peel strength between the barrier layer and the sealing layer. After removing the bottom film, an interlayer separation membrane is formed.

[0010] The tensile strength of the base film is 150MPa-200MPa and the elongation is 110%-140%; preferably, the material of the base film is CPP.

[0011] The peel strength between the bottom film and the sealing layer on the supporting composite layer is less than 0.1 N / 15 mm.

[0012] The peel strength between the barrier layer and the sealing layer is greater than 1N / 15mm, preferably 1-7N / 15mm, and more preferably 2-4N / 15mm.

[0013] The thickness of the base film is 30-70 micrometers, preferably 50-70 micrometers.

[0014] The release layer consists of two layers: a base layer formed by curing an acrylic colloid and a top layer formed by curing a polyurethane colloid; the base layer is disposed adjacent to the barrier layer.

[0015] The coating amount of the primer layer is 0.05-0.15 g / m². 2 The coating amount of the adhesive layer is 0.3-4.5 g / m². 2 The greater the amount of adhesive coating, the greater the peel strength. To achieve both the peeling effect between the barrier layer and the sealing layer, and to maintain the seal between the sealing layer and the container, the preferred coating amount of the topcoat layer is 0.5-1.5 g / m³. 2 .

[0016] The barrier layer is made of Al;

[0017] And / or, the sealing layer is made of CPP.

[0018] The thickness of the barrier layer is 30-70 micrometers;

[0019] And / or, the thickness of the sealing layer is 30-70 micrometers.

[0020] The curing temperature for the release layer is 40-75℃, and the curing time is 48-72h; preferably 65±5℃, 48h.

[0021] The technical solution of this invention has the following advantages:

[0022] 1. The present invention provides a method for preparing an interlayer separation membrane, comprising first forming a support composite layer containing a sealing layer, then cutting the support composite layer to form a drinking spout on the sealing layer, then using an colloid to composite the sealing layer and a barrier layer, wherein the colloid forms a release layer between the sealing layer and the barrier layer, and finally removing the bottom film on the sealing layer to form an interlayer separation membrane having a barrier layer, a release layer and a sealing layer; the bottom film is selected from materials with a compressive strength between 50MPa and 350MPa and an elongation between 90% and 500%, which can ensure that the sealing layer is cut to achieve the purpose of forming a drinking spout, and the sealing layer will not deform; at the same time, the prepared interlayer separation membrane has good sealing performance and easy peeling, effectively ensuring the yield of the prepared interlayer separation membrane.

[0023] 2. In the preparation method of the interlayer separation membrane provided by this invention, the bottom membrane is made of CPP, which not only has suitable compressive strength and elongation, but also allows for bonding with the sealing layer using either an electrostatic method or an adhesive method. The only requirement is that the peel strength between the bottom membrane and the sealing layer is less than 0.1 N / 15 mm. This design ensures more effective peeling and removal of the bottom membrane in the final step, and offers more bonding options. Specifically, when using an electrostatic bonding method, no colloid is needed; electrostatic adsorption between the materials effectively ensures bonding between the bottom membrane and the sealing layer, meeting cutting requirements while effectively saving preparation costs. When using an adhesive bonding method, the composite stability is higher, and the operation is more stable.

[0024] 3. A method for preparing an interlayer separation membrane according to the present invention, wherein the peel strength between the bottom film and the sealing layer is less than 0.1 N / 15 mm, and the peel strength between the barrier layer and the sealing layer is set to be greater than 1 N / 15 mm, the two work together to avoid the bottom film removal process affecting the peeling layer. At the same time, further limiting the peel strength between the barrier layer and the sealing layer to 2-4 N / 15 mm ensures that the sealing layer and the barrier layer can be separated more easily during use, thereby effectively ensuring that the prepared interlayer separation membrane has good sealing performance and easy peeling.

[0025] 4. The method for preparing an interlayer separation membrane according to the present invention does not require a high-precision roller die cutting edge, nor does it require frequent replacement of the roller die to maintain its precision; at the same time, the cutting effect can be judged in advance by peeling off the bottom film and sealing film, without having to wait until the cover film is manufactured and sealed with the cup to peel it off to judge the cutting situation, thus shortening the production cycle and improving the yield. Detailed Implementation

[0026] The following embodiments are provided to better understand the present invention and are not limited to the preferred embodiments described. They do not constitute a limitation on the content and scope of protection of the present invention. Any product that is the same as or similar to the present invention, derived by any person under the guidance of the present invention or by combining the features of the present invention with other prior art, falls within the protection scope of the present invention.

[0027] For experiments not specifically described in the examples, the procedures or conditions should be followed according to the conventional experimental procedures described in the literature in this field. Reagents or instruments whose manufacturers are not specified are all commercially available conventional reagent products.

[0028] In the following embodiments, the method for testing tensile strength is GB / T 28118-2011;

[0029] The testing methods for elongation are: GB 1040.3 (thickness < 1 mm), GB 1040.2 (thickness > 1 mm);

[0030] The test method for peel strength is GB / T 8808-1988;

[0031] The method for detecting coating amount is as follows:

[0032] Step 1 (Sampling): Take a flat sample approximately 100cm long from the machine. Step 2 (Sample Cutting): Cut four 100cm square centimeter samples using a sampling knife. Step 3 (Weighing Gross Weight): Weigh the gross weight of the adhesive using an electronic balance and record the result. Step 4 (Wiping Adhesive): Wipe the aluminum foil repeatedly with a cloth soaked in ethyl acetate at least three times, carefully observing whether the adhesive is completely removed. Step 5 (Weighing Net Weight): Weigh the net weight of the aluminum foil using an electronic balance and record the result. Step 6 (Calculation): Use a calculator with the formula: (Gross Weight - Net Weight) / Number of Samples = Adhesive Weight per Sample; calculate the coating amount based on the area of ​​each sample.

[0033] Example 1:

[0034] A method for preparing an interlayer separation membrane, comprising:

[0035] Material preparation: Obtain a sealing layer with a thickness of 50 μm and made of CPP; obtain a base film with a thickness of 55 μm and made of CPP, wherein the tensile strength of the base film is 170-200 MPa and the elongation is 130-150% (average tensile strength is 173.44 MPa and average elongation is 138.80%); obtain a barrier layer with a thickness of 50 μm and made of Al; obtain an acrylate colloidal solution and a polyurethane colloidal solution;

[0036] Drinking spout forming: The sealing layer and the bottom film are combined to form a supporting composite layer, and the supporting composite layer is cut to form the drinking spout on the sealing layer;

[0037] Release layer forming: First, an acrylic colloid solution to form the primer layer is applied to the barrier layer. Then, a polyurethane colloid solution is applied onto the acrylic colloid solution used to form the primer layer. After drying, the acrylic colloid and the polyurethane colloid form the primer layer and the topcoat layer, respectively. The coating amount of the primer layer on the barrier layer is 0.1-0.15 g / m². 2 The coating amount of the adhesive layer is 0.5-1.5 g / m². 2 The sealing layer side of the supporting composite layer is brought into contact with the top adhesive layer side of the barrier layer and laminated together. After heat curing at 65±5℃ for 48 hours, a release layer is formed between the barrier layer and the sealing layer.

[0038] Obtaining the interlayer separation membrane: After the release layer is formed, the average peel strength between the barrier layer and the sealing layer is about 2.71 N / 15 mm, while the peel strength between the bottom film and the sealing layer is less than 0.1 N / 15 mm. Therefore, the bottom film is very easy to peel off from the sealing layer. After removing the bottom film, the interlayer separation membrane is obtained. Then, the interlayer separation membrane is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer membrane to complete the die-cutting and form the sealing cover film.

[0039] Example 2:

[0040] A method for preparing an interlayer separation membrane, comprising:

[0041] Material preparation: Obtain a sealing layer with a thickness of 50 μm and made of CPP; obtain a base film with a thickness of 70 μm and made of CPP, wherein the base film has a strength of 300-350 MPa and an elongation of 90-130%; obtain a barrier layer with a thickness of 50 μm and made of Al; obtain an acrylate colloidal solution; obtain a polyurethane colloidal solution;

[0042] Drinking spout forming: The sealing layer and the bottom film are combined to form a supporting composite layer, and the supporting composite layer is cut to form the drinking spout on the sealing layer;

[0043] Release layer forming: First, an acrylic colloid solution to form the primer layer is applied to the barrier layer. Then, a polyurethane colloid solution is applied onto the acrylic colloid solution used to form the primer layer. After drying, the acrylic colloid and the polyurethane colloid form the primer layer and the topcoat layer, respectively. The coating amount of the primer layer on the barrier layer is 0.05-0.15 g / m². 2 The coating amount of this adhesive layer is 1.5-2.5 g / m². 2 The sealing layer side of the supporting composite layer is brought into contact with the top adhesive layer side of the barrier layer and laminated together. After heat curing at 65±5℃ for 48 hours, a release layer is formed between the barrier layer and the sealing layer.

[0044] Obtaining the interlayer separation membrane: After the release layer is formed, the average peel strength between the barrier layer and the sealing layer is about 3.35 N / 15 mm, while the peel strength between the bottom film and the sealing layer is less than 0.1 N / 15 mm. Therefore, the bottom film is very easy to peel off from the sealing layer. After removing the bottom film, the interlayer separation membrane is obtained. Then, the interlayer separation membrane is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer membrane to complete the die-cutting and form the sealing cover film.

[0045] Example 3:

[0046] A method for preparing an interlayer separation membrane, comprising:

[0047] Material preparation: Obtain a sealing layer with a thickness of 50 μm and made of CPP; obtain a base film with a thickness of 45 μm and made of CPP, wherein the tensile strength of the base film is 130-160 MPa and the elongation is 150-180%; obtain a barrier layer with a thickness of 50 μm and made of Al; obtain an acrylate colloidal solution and a polyurethane colloidal solution;

[0048] Drinking spout forming: The sealing layer and the bottom film are combined to form a supporting composite layer, and the supporting composite layer is cut to form the drinking spout on the sealing layer;

[0049] Release layer forming: First, an acrylic colloid solution to form the primer layer is applied to the barrier layer. Then, a polyurethane colloid solution is applied onto the acrylic colloid solution used to form the primer layer. After drying, the acrylic colloid and the polyurethane colloid form the primer layer and the topcoat layer, respectively. The coating amount of the primer layer on the barrier layer is 0.05-0.15 g / m². 2 The coating amount of this adhesive layer is 2-3 g / m². 2 The sealing layer side of the supporting composite layer is brought into contact with the adhesive layer side of the barrier layer and laminated together. After heat curing at 45±5℃ for 72 hours, a release layer is formed between the barrier layer and the sealing layer.

[0050] Obtaining the interlayer separation membrane: After the release layer is formed, the average peel strength between the barrier layer and the sealing layer is about 5.42 N / 15 mm, while the peel strength between the bottom film and the sealing layer is less than 0.1 N / 15 mm. Therefore, the bottom film is very easy to peel off from the sealing layer. After removing the bottom film, the interlayer separation membrane is obtained. Then, the interlayer separation membrane is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer membrane to complete the die-cutting and form the sealing cover film.

[0051] Example 4:

[0052] A method for preparing an interlayer separation membrane, comprising:

[0053] Material preparation: Obtain a sealing layer with a thickness of 50 μm and made of CPP; obtain a base film with a thickness of 30 μm and made of CPP, wherein the base film has a strength of 90-130 MPa and an elongation of 180%-200%; obtain a barrier layer with a thickness of 50 μm and made of Al; obtain an acrylate colloidal solution; obtain a polyurethane colloidal solution;

[0054] Drinking spout forming: The sealing layer and the bottom film are combined to form a supporting composite layer, and the supporting composite layer is cut to form the drinking spout on the sealing layer;

[0055] Release layer formation: First, an acrylic colloid solution is applied to the Al layer. Then, a polyurethane colloid solution is applied over the acrylic colloid solution to form the base coat. After drying, the acrylic colloid and polyurethane colloid form the base coat and top coat, respectively. The coating amount of the base coat on the Al layer is 0.05-0.15 g / m². 2 The coating amount of this adhesive layer is 3.5-4.5 g / m². 2 The sealing layer side of the supporting composite layer is brought into contact with the top adhesive layer side of the barrier layer and laminated together. After heat curing at 65±5℃ for 48 hours, a release layer is formed between the barrier layer and the sealing layer.

[0056] Obtaining the interlayer separation membrane: After the release layer is formed, the average peel strength between the barrier layer and the sealing layer is about 6.83 N / 15 mm, while the peel strength between the bottom film and the sealing layer is less than 0.1 N / 15 mm. Therefore, the bottom film is very easy to peel off from the sealing layer. After removing the bottom film, the interlayer separation membrane is obtained. Then, the interlayer separation membrane is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer membrane to complete the die-cutting and form the sealing cover film.

[0057] Example 5:

[0058] A method for preparing an interlayer separation membrane, comprising:

[0059] Material preparation: Obtain a sealing layer with a thickness of 30 μm and made of CPP; obtain a base film with a thickness of 55 μm and made of CPP, wherein the base film has a strength of 160-180 MPa and an elongation of 130%-150%; obtain a barrier layer with a thickness of 35 μm and made of Al; obtain an acrylate colloidal solution; obtain a polyurethane colloidal solution;

[0060] Drinking spout forming: The sealing layer and the bottom film are combined to form a supporting composite layer, and the supporting composite layer is cut to form the drinking spout on the sealing layer;

[0061] Release layer forming: First, an acrylic colloid solution is applied to the Al layer. Then, a polyurethane colloid solution is applied onto the acrylic colloid solution used to form the primer layer. After drying, the acrylic colloid and polyurethane colloid form the primer layer and topcoat layer, respectively. The coating amount of the primer layer on the Al layer is 0.1-0.15 g / m². 2 The coating amount of this adhesive layer is 0.5-1.5 g / m². 2 The sealing layer side of the support composite layer is bonded to the adhesive layer side of the barrier layer, and after heat curing at 65±5℃ for 48 hours, a release layer is formed between the barrier layer and the sealing layer.

[0062] Obtaining the interlayer separation membrane: After the release layer is formed, the average peel strength between the barrier layer and the sealing layer is about 2.75 N / 15 mm, while the peel strength between the bottom film and the sealing layer is less than 0.1 N / 15 mm. Therefore, the bottom film is very easy to peel off from the sealing layer. After removing the bottom film, the interlayer separation membrane is obtained. Then, the interlayer separation membrane is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer membrane to complete the die-cutting and form the sealing cover film.

[0063] Example 6:

[0064] A method for preparing an interlayer separation membrane, comprising:

[0065] Material preparation: Obtain a sealing layer with a thickness of 30 μm and made of CPP; obtain a base film with a thickness of 30 μm and made of CPP, wherein the base film has a strength of 90-120 MPa and an elongation of 180%-200%; obtain a barrier layer with a thickness of 35 μm and made of Al; obtain an acrylate colloidal solution; obtain a polyurethane colloidal solution;

[0066] Drinking spout forming: The sealing layer and the bottom film are combined to form a supporting composite layer, and the supporting composite layer is cut to form the drinking spout on the sealing layer;

[0067] Release layer forming: First, an acrylic colloid solution is applied to the Al layer. Then, a polyurethane colloid solution is applied onto the acrylic colloid solution used to form the primer layer. After drying, the acrylic colloid and polyurethane colloid form the primer layer and topcoat layer, respectively. The coating amount of the primer layer on the Al layer is 0.1-0.15 g / m². 2 The coating amount of this adhesive layer is 0.5-1.5 g / m². 2 The sealing layer side of the support composite layer is bonded to the adhesive layer side of the barrier layer, and after heat curing at 65±5℃ for 48 hours, a release layer is formed between the barrier layer and the sealing layer.

[0068] Obtaining the interlayer separation membrane: After the release layer is formed, the average peel strength between the barrier layer and the sealing layer is about 2.83 N / 15 mm, while the peel strength between the bottom film and the sealing layer is less than 0.1 N / 15 mm. Therefore, the bottom film is very easy to peel off from the sealing layer. After removing the bottom film, the interlayer separation membrane is obtained. Then, the interlayer separation membrane is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer membrane to complete the die-cutting and form the sealing cover film.

[0069] Comparative Example 1:

[0070] The difference between this comparative example and the embodiment is that the base film is made of PE material whose tensile strength and elongation are both outside the range values. The specific process is as follows:

[0071] Material preparation: Obtain a sealing layer with a thickness of 50 μm and made of CPP; obtain a base film with a thickness of 70 μm and made of PE with electrostatic properties, wherein the tensile strength of the base film is 10-20 MPa and the elongation is 530%-570%; obtain a barrier layer with a thickness of 50 μm and made of Al; obtain an acrylic ester colloidal solution; obtain a polyurethane colloidal solution;

[0072] Drinking spout forming: The sealing layer and the bottom film are combined to form a supporting composite layer, and the supporting composite layer is cut to form the drinking spout on the sealing layer;

[0073] Release layer forming: First, an acrylic colloid solution is applied to the Al layer, then a polyurethane colloid solution is applied on top of the acrylic colloid solution to form the base coat. After drying, the acrylic colloid and polyurethane colloid form the base coat and top coat, respectively. The coating amount of the base coat on the barrier layer is 0.1-0.15 g / m². 2 The coating amount of this adhesive layer is 0.5-1.5 g / m². 2 The release layer and the barrier layer are combined and then thermo-cured at 65±5℃ for 48 hours to form a release layer between the barrier layer and the sealing layer.

[0074] Obtaining the interlayer separation membrane: After the release layer is formed, the average peel strength between the barrier layer and the sealing layer is about 2.77 N / 15 mm, while the peel strength between the bottom film and the sealing layer is less than 0.1 N / 15 mm. Therefore, the bottom film is very easy to peel off from the sealing layer. After removing the bottom film, the interlayer separation membrane is obtained. Then, the interlayer separation membrane is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer membrane to complete the die-cutting and form the sealing cover film.

[0075] Comparative Example 2:

[0076] The difference between this comparative example and the embodiment is that: the barrier layer and the sealing layer are directly laminated and then cut to form a drinking opening on the sealing layer; the specific process is as follows:

[0077] Materials preparation: Obtain an 80μm thick sealing layer made of CPP; obtain a 50μm thick barrier layer made of Al; obtain an acrylate colloidal solution; obtain a polyurethane colloidal solution;

[0078] Release layer forming: First, an acrylic colloid solution is applied to the barrier layer. Then, a polyurethane colloid solution is applied onto the acrylic colloid solution used to form the base coat. After drying, the acrylic colloid and polyurethane colloid form the base coat and top coat, respectively. The coating amount of the base coat on the barrier layer is 0.1-0.15 g / m². 2 The coating amount of this adhesive layer is 0.5-1.5 g / m². 2 The sealing layer side of the supporting composite layer is brought into contact with the top adhesive layer side of the barrier layer and laminated together. After heat curing at 65±5℃ for 48 hours, a release layer is formed between the barrier layer and the sealing layer.

[0079] Forming the drinking spout: Adjust the cutting depth of the roller die to cut the positioning line at the break point between the drinking spout and the edge of the cap film, so that the drinking spout is formed on the sealing layer, thus preparing the interlayer separation membrane.

[0080] Obtaining the sealing cap film: The interlayer separation film is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer film to complete the die-cutting and form the sealing cap film.

[0081] Comparative Example 3:

[0082] The difference between this comparative example and the embodiment is that: the barrier layer and the sealing layer are directly laminated and then cut to form a drinking opening on the sealing layer; the specific process is as follows:

[0083] Materials preparation: Obtain a sealing layer with a thickness of 50 μm made of CPP; obtain a barrier layer with a thickness of 80 μm made of Al; obtain an acrylate colloidal solution; obtain a polyurethane colloidal solution;

[0084] Release layer forming: First, an acrylic colloid solution is applied to the barrier layer. Then, a polyurethane colloid solution is applied onto the acrylic colloid solution used to form the base coat. After drying, the acrylic colloid and polyurethane colloid form the base coat and top coat, respectively. The coating amount of the base coat on the barrier layer is 0.1-0.15 g / m². 2 The coating amount of this adhesive layer is 0.5-1.5 g / m². 2 The sealing layer side of the supporting composite layer is brought into contact with the top adhesive layer side of the barrier layer and laminated together. After heat curing at 65±5℃ for 48 hours, a release layer is formed between the barrier layer and the sealing layer.

[0085] Forming the drinking spout: Adjust the cutting depth of the roller die to cut the positioning line at the break point between the drinking spout and the edge of the cap film, so that the drinking spout is formed on the sealing layer, thus preparing the interlayer separation membrane.

[0086] Obtaining the sealing cap film: The interlayer separation film is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer film to complete the die-cutting and form the sealing cap film.

[0087] Comparative Example 4:

[0088] The difference between this comparative example and the embodiment is that: the barrier layer and the sealing layer are directly laminated and then cut to form a drinking opening on the sealing layer; the specific process is as follows:

[0089] Materials preparation: Obtain a sealing layer with a thickness of 50 μm made of CPP; obtain a barrier layer with a thickness of 50 μm made of Al; obtain an acrylate colloidal solution; obtain a polyurethane colloidal solution;

[0090] Release layer forming: First, an acrylic colloid solution to form the primer layer is applied to the barrier layer. Then, a polyurethane colloid solution is applied onto the acrylic colloid solution used to form the primer layer. After drying, the acrylic colloid and the polyurethane colloid form the primer layer and the topcoat layer, respectively. The coating amount of the primer layer on the barrier layer is 0.1-0.15 g / m². 2 The coating amount of this adhesive layer is 0.5-1.5 g / m². 2The sealing layer side of the supporting composite layer is brought into contact with the top adhesive layer side of the barrier layer and laminated together. After heat curing at 65±5℃ for 48 hours, a release layer is formed between the barrier layer and the sealing layer.

[0091] Forming the drinking spout: Adjust the cutting depth of the roller die to cut the positioning line at the break point between the drinking spout and the edge of the cap film, so that the drinking spout is formed on the sealing layer, thus preparing the interlayer separation membrane.

[0092] Obtaining the sealing cap film: The interlayer separation film is embossed and die-cut. The die-cutting knife positions the outer contour positioning line of the sealing layer film to complete the die-cutting and form the sealing cap film.

[0093] Experimental example: The performance of the support composite layers prepared in the examples and comparative examples was tested. The performance test items included hole cutting effect, curling effect, sealing effect and easy peeling effect.

[0094] The method for testing the hole-cutting effect is as follows: randomly cut off a section, peel it apart and see if the hole is completely cut through; if it is completely cut through, the effect is good; if the cut is not completely broken and there is a connection, the effect is poor.

[0095] The method for detecting the curling effect is as follows: the prepared interlayer separation membrane is wound up, and the tightness of the roll is checked; if the roll is tight and not loose, the effect is good, and if the roll is loose, the effect is poor.

[0096] The specific results of the above-mentioned hole-cutting and curling effects are shown in Table 1 below.

[0097] Table 1

[0098] Hole cutting effect Curling effect Example 1 good good Example 2 good good Example 3 good good Example 4 good good Example 5 good good Example 6 good good Comparative Example 1 Difference good

[0099] The sealing films prepared using the examples and comparative examples were hot-pressed with PP cups at 240℃ and 0.5MPa for 1 second. After hot pressing, the cups were tested for sealing and ease of removal. The sealing test conditions were: negative pressure 50Kpa, 30s / 60s for leakage. The ease of removal test method was: a 15mm sample film was prepared, and a 180° peel test was performed to detect the force required for peeling, i.e., the peel strength in Table 2 below.

[0100] The test results for the sealing and easy-to-open properties are shown in Table 2 below.

[0101] Table 2

[0102]

[0103] Among them, sealing films that are leak-free and do not fray are considered qualified finished products.

[0104] The results above show that only by using a material with a compressive strength between 50MPa and 350MPa and an elongation between 90% and 500% as the base film and sealing layer to form a supporting composite layer, forming the drinking spout on the supporting composite layer, and finally bonding a barrier layer to form an interlayer separation membrane, can both sealing performance and easy peeling be guaranteed.

[0105] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for producing an interlayer separation film, characterized by, The application relates to a method for manufacturing a drinking straws, which comprises the following steps: a sealing layer is compounded with a bottom film to form a supporting composite layer, the supporting composite layer is cut to form a drinking port on the sealing layer; the bottom film is made of a material with a tensile strength of 50-350 MPa and an elongation of 90-500%; the sealing layer on the supporting composite layer is compounded with a barrier layer through a colloid, the colloid is solidified between the barrier layer and the sealing layer to form a peeling layer; the peeling strength between the bottom film and the sealing layer on the supporting composite layer is less than 0.1 N / 15 mm; the peeling strength between the barrier layer and the sealing layer is greater than 1 N / 15 mm; and the bottom film is removed to form an interlayer separation film. The tensile strength of the bottom film is 150-200 MPa, and the elongation is 110-140%. The material of the bottom film is CPP. The peeling strength between the barrier layer and the sealing layer is 1-7 N / 15 mm. The peeling strength between the barrier layer and the sealing layer is 2-4 N / 15 mm.

2. The method for producing an interlayer release film according to claim 1, characterized by, The thickness of the bottom film is 30-70 microns.

3. The method of claim 2, wherein the polymeric material is a polyolefin. The peeling layer is composed of a bottom adhesive layer formed by an acrylate colloid and a surface adhesive layer formed by a polyurethane colloid; the bottom adhesive layer is arranged adjacent to the barrier layer.

4. The method of claim 1, wherein the method further comprises the step of applying a primer to the surface of the substrate. The coating amount of the bottom adhesive layer is 0.05-0.15 g / m2, and the coating amount of the surface adhesive layer is 0.3-4.5 g / m2.

5. The method of claim 4, wherein the polymeric material is a polyolefin. The material of the barrier layer is Al.

6. The method of claim 1, wherein the interlayer separation film is prepared by the steps of: The material of the sealing layer is CPP.

7. The method for preparing an interlayer separation membrane according to claim 1, characterized in that, The thickness of the barrier layer is 35-70 microns.

8. The method of claim 7, wherein the method further comprises the step of applying a primer to the surface of the substrate. The thickness of the sealing layer is 30-70 microns.

9. The method for preparing an interlayer separation membrane according to claim 1, characterized in that, The solidification temperature of the peeling layer is 40-75 DEG C, and the solidification time is 48-72 h. The solidification temperature of the peeling layer is 65+ / -5 DEG C, and the solidification time is 48 h.

10. The method of claim 7, wherein the method further comprises the step of applying a primer to the surface of the substrate. ​ ​ 11. The method of claim 1-10, wherein the method is characterized by, ​ 12. The method of claim 11, wherein the method further comprises the step of applying a primer to the surface of the substrate. ​

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