A method for producing a composite sheet for medical packaging

Abstract

The publicly disclosed method for manufacturing composite sheets for pharmaceutical packaging is as follows: S1 Mix 12-19 parts of LLDPE granules, 65-72 parts of LDPE granules, 12-18 parts of titanium dioxide, and 0.6-1.2 parts of silica, heat to melt and extrude, blow into film, cool and form, and rotate and roll to obtain the middle layer milky white PE film; S2 Flexographically print graphics on the inner surface of the outer PE film; S3 Compositely connect the obtained middle layer milky white PE film and the outer PE film with printed graphics to form a semi-finished composite sheet structure; S4 Solventlessly composite the semi-finished composite sheet with an Al barrier film and an inner PE film in sequence using EAA adhesive to form a composite sheet structure of "outer PE film layer - flexographic ink layer - middle milky white PE film layer - first EAA adhesive layer - Al barrier film layer - second EAA adhesive layer - inner PE film layer". In this manufacturing method, the self-made intermediate milky white PE film layer meets the whiteness standard and is thin and flat. It can reduce the overall thickness of the composite sheet while maintaining whiteness, thereby improving the quality problem of bulging edges caused by excessive thickness.

Description

Technical Field

[0001] This invention belongs to the field of composite sheets, and specifically relates to a method for manufacturing a composite sheet for pharmaceutical packaging. Background Technology

[0002] The composite sheets used in the pharmaceutical packaging industry can be used to make tubes for plasters. In order to achieve sufficient whiteness, the amount of white masterbatch added to the milky white extruded layer in the middle of the composite sheet needs to be above 16%. In order to meet the content ratio of this white masterbatch, the extruded layer is often made very thick, usually above 60um. An excessively thick milky white extruded layer is prone to uneven extrusion thickness deviation, which eventually leads to bulging edges of the composite sheet, affecting the customer's tube manufacturing and use.

[0003] In addition, the composite sheets used for pharmaceutical packaging are usually gravure printed on the outer transparent PE film layer. Gravure printing has the problem of high ink cost and high plate making cost due to the large amount of ink applied. If the graphics on the PE film layer are printed using the lower cost flexographic printing method, there will be a problem of blurry edges of the graphics. Summary of the Invention

[0004] Based on the content in the background art, the present invention provides a method for manufacturing a composite sheet for pharmaceutical packaging, comprising the following steps:

[0005] S1. Preparation of the intermediate layer milky white PE film: Mix 12-19 parts of LLDPE granules, 65-72 parts of LDPE granules, 12-18 parts of titanium dioxide and 0.6-1.2 parts of silica according to the following weight proportions, then heat and melt the mixture, extrude it through an extruder, blow it into a film, cool it to form a film, and then rotate and rewind it to obtain the intermediate layer milky white PE film. By controlling the blowing pressure, the thickness of the intermediate layer milky white PE film is 35-45 μm. In this raw material formula, titanium dioxide is a white masterbatch. The raw material ratio can make the whiteness of the intermediate layer milky white PE film meet the standard and be thin and flat. While maintaining whiteness, the overall thickness of the composite sheet can be reduced, thereby improving the quality problems of blistering and edge swaying caused by excessive thickness.

[0006] S2. Flexographic printing of images and text on the inner surface of the outer PE film;

[0007] S3. The intermediate milky white PE film obtained in step S1 and the outer PE film printed with graphics are combined and connected to form a semi-finished composite sheet structure of "outer PE film layer - flexographic ink layer - intermediate milky white PE film layer".

[0008] S4. The semi-finished composite sheet obtained in step S3 is sequentially laminated with an Al barrier film and an inner PE film using EAA adhesive to form a composite sheet structure of "outer PE film layer - flexographic ink layer - middle milky white PE film layer - first EAA adhesive layer - Al barrier film layer - second EAA adhesive layer - inner PE film layer".

[0009] The thicknesses of each layer of the resulting composite sheet are as follows: the outer PE film layer is 90 μm thick, the middle milky white PE film layer is 35-45 μm thick, the first EAA adhesive layer is 30 μm thick, the Al barrier film layer is 30 μm thick, the second EAA adhesive layer is 30 μm thick, and the inner PE film layer is 70 μm thick. This composite sheet meets the whiteness standard and has no quality issues such as bulging edges.

[0010] Preferably, in step S1, the weight percentages of the LLDPE granules are 15.4 parts, the weight percentages of the LDPE granules are 68.7 parts, the weight percentages of the titanium dioxide are 15 parts, and the weight percentages of the silica are 0.9 parts.

[0011] Preferably, in step S1, the die temperature of the extruder is 175-195°C.

[0012] Further, the flexographic printing method in step S2 is as follows: First, a high-adhesion ink is applied to the flexible resin printing plate using an anilox roller. Then, the flexible resin printing plate is bonded to the inner surface of the PE film. Finally, pressure is applied by an impression cylinder to transfer the image ink on the flexible resin printing plate to the PE film. The flexible resin printing plate consists of multiple staggered vertical image plates, specifically five. The impression cylinder spans the multiple vertical image plates of the flexible resin printing plate. The high-adhesion ink is Solimax series ink from D.E.S. Pigment Ltd. This flexible resin printing plate, containing multiple staggered vertical image plates, can disperse the printing pressure of the impression cylinder, making the printing pressure uniform throughout. Combined with the high-adhesion ink, it can successfully overcome the problem of blurred image edges in flexographic printing on the PE film layer. Through the flexographic printing method of this application, the images printed on the inner surface of the PE film layer are clear and not blurred.

[0013] Preferably, the pressure applied by the impression roller is 0.2-0.4 MPa.

[0014] Through the above technical solutions, the present invention has at least the following beneficial effects:

[0015] In the manufacturing method of the composite sheet for pharmaceutical packaging of the present invention, the intermediate layer is replaced by the existing milky white extruded composite layer by using a milky white PE layer formed by blown film. The self-made intermediate milky white PE film layer has the required whiteness and is thin and flat. It can reduce the overall thickness of the composite sheet while maintaining the whiteness, thereby improving the quality problems of bubbling and edge swaying caused by excessive thickness.

[0016] In the preferred embodiment, by using a flexible resin printing plate composed of multiple staggered vertical graphic plates, combined with ink with high adhesion, the problem of blurred edges of graphics in flexographic printing on PE film can be successfully overcome. Through the flexographic printing method described in this application, the graphics printed on the inner surface of the PE film are clear and not blurred, which can replace the traditional gravure printing method in composite sheets, thereby reducing the cost of plate making and the amount of ink used, achieving the goal of economy and environmental protection. Attached Figure Description

[0017] Figure 1 This is a schematic diagram showing the disassembly of each layer of the composite sheet for pharmaceutical packaging prepared in Examples 1 to 3 of this application;

[0018] Figure 2 This is a schematic diagram of the structure of the misprinted flexible resin printing plate used in Embodiments 1 to 3 of this application;

[0019] Figure 3 This is a schematic diagram of the structure of a conventional flexible resin printing plate used in Comparative Example 2 of this application. Detailed Implementation

[0020] The technical solution of the invention will be clearly and completely described below with reference to the accompanying drawings and embodiments. The application of the invention is not limited to the embodiments described.

[0021] Example 1

[0022] A method for manufacturing a composite sheet for pharmaceutical packaging, comprising the following steps:

[0023] S1. Preparation of the intermediate layer milky white PE film: Mix 15.4 parts of LLDPE granules, 68.7 parts of LDPE granules, 15 parts of titanium dioxide and 0.9 parts of silica according to the following weight proportions, then heat and melt the mixture, extrude it through an extruder, blow it into a film, cool and shape it, and then rotate and rewind it to obtain the intermediate layer milky white PE film; the die temperature of the extruder is 185℃, and the thickness of the intermediate layer milky white PE film is 40um by controlling the blown film pressure; in this raw material formula, titanium dioxide is a white masterbatch, and the raw material ratio can make the whiteness of the intermediate layer milky white PE film meet the standard and be thin and flat. While maintaining whiteness, the overall thickness of the composite sheet can be reduced, thereby improving the quality problems of blistering and edge swaying caused by excessive thickness.

[0024] S2. Flexographic printing of images and text on the inner surface of the outer PE film. The flexographic printing method is as follows: First, a high-adhesion ink is applied to a flexible resin printing plate using an anilox roller. Then, the flexible resin printing plate is bonded to the inner surface of the PE film. Finally, pressure is applied using an impression cylinder at a pressure of 0.3 MPa to transfer the image and text ink from the flexible resin printing plate to the PE film. (Refer to...) Figure 2 The flexible resin printing plate is composed of multiple staggered vertical graphic plates, specifically five. The impression cylinder spans the multiple vertical graphic plates of the flexible resin printing plate. The high-adhesion ink is Solimax series ink from D.E.S. Pigment Ltd. This flexible resin printing plate, which includes multiple staggered vertical graphic plates, can disperse the printing pressure of the impression cylinder, making the printing pressure uniform in all places. Combined with the high-adhesion ink, it can successfully overcome the problem of blurred edges of images when flexographic printing on PE film. Through the flexographic printing method of this application, the images printed on the inner surface of PE film are clear and not blurred.

[0025] S3. Combine the intermediate milky white PE film obtained in step S1 with the outer PE film printed with graphics in step S2 to form a semi-finished composite sheet structure of "outer PE film layer - flexographic ink layer - intermediate milky white PE film layer".

[0026] S4. The semi-finished composite sheet obtained in step S3 is sequentially laminated with an Al barrier film and an inner PE film using EAA adhesive to form a composite sheet structure of "outer PE film layer - flexographic ink layer - middle milky white PE film layer - first EAA adhesive layer - Al barrier film layer - second EAA adhesive layer - inner PE film layer".

[0027] The thicknesses of each layer of the resulting composite sheet are as follows: the outer PE film layer is 90 μm thick, the middle milky white PE film layer is 40 μm thick, the first EAA adhesive layer is 30 μm thick, the Al barrier film layer is 30 μm thick, the second EAA adhesive layer is 30 μm thick, and the inner PE film layer is 70 μm thick. This composite sheet meets the whiteness standard and has no quality issues such as bulging edges.

[0028] Example 2

[0029] A method for manufacturing a composite sheet for pharmaceutical packaging, comprising the following steps:

[0030] S1. Preparation of the intermediate layer milky white PE film: Mix 12 parts of LLDPE granules, 72 parts of LDPE granules, 18 parts of titanium dioxide and 0.6 parts of silica according to the following weight proportions, then heat and melt the mixture, extrude it through an extruder, blow it into a film, cool and shape it, and then rotate and rewind it to obtain the intermediate layer milky white PE film; the die temperature of the extruder is 195℃, and the thickness of the intermediate layer milky white PE film is 35um by controlling the blown film pressure; in this raw material formula, titanium dioxide is a white masterbatch, and the raw material ratio can make the whiteness of the intermediate layer milky white PE film meet the standard and be thin and flat. While maintaining whiteness, the overall thickness of the composite sheet can be reduced, thereby improving the quality problems of bubbling and edge swaying caused by excessive thickness.

[0031] S2. Flexographic printing of images and text on the inner surface of the outer PE film. The flexographic printing method is as follows: First, a high-adhesion ink is applied to a flexible resin printing plate using an anilox roller. Then, the flexible resin printing plate is bonded to the inner surface of the PE film. Finally, pressure is applied using an impression cylinder at a pressure of 0.2 MPa to transfer the image and text ink from the flexible resin printing plate to the PE film. (Refer to...) Figure 2 The flexible resin printing plate is composed of multiple staggered vertical graphic plates, specifically five. The impression cylinder spans the multiple vertical graphic plates of the flexible resin printing plate. The high-adhesion ink is Solimax series ink from D.E.S. Pigment Ltd. This flexible resin printing plate, which includes multiple staggered vertical graphic plates, can disperse the printing pressure of the impression cylinder, making the printing pressure uniform in all places. Combined with the high-adhesion ink, it can successfully overcome the problem of blurred edges of images when flexographic printing on PE film. Through the flexographic printing method of this application, the images printed on the inner surface of PE film are clear and not blurred.

[0032] S3. Combine the intermediate milky white PE film obtained in step S1 with the outer PE film printed with graphics in step S2 to form a semi-finished composite sheet structure of "outer PE film layer - flexographic ink layer - intermediate milky white PE film layer".

[0033] S4. The semi-finished composite sheet obtained in step S3 is sequentially laminated with an Al barrier film and an inner PE film using EAA adhesive to form a composite sheet structure of "outer PE film layer - flexographic ink layer - middle milky white PE film layer - first EAA adhesive layer - Al barrier film layer - second EAA adhesive layer - inner PE film layer".

[0034] The thicknesses of each layer of the resulting composite sheet are as follows: the outer PE film layer is 90 μm thick, the middle milky white PE film layer is 35 μm thick, the first EAA adhesive layer is 30 μm thick, the Al barrier film layer is 30 μm thick, the second EAA adhesive layer is 30 μm thick, and the inner PE film layer is 70 μm thick. This composite sheet meets the whiteness standard and has no quality issues such as bulging edges.

[0035] Example 3

[0036] A method for manufacturing a composite sheet for pharmaceutical packaging, comprising the following steps:

[0037] S1. Preparation of the intermediate layer milky white PE film: Mix 19 parts of LLDPE granules, 65 parts of LDPE granules, 12 parts of titanium dioxide and 1.2 parts of silica according to the following weight proportions, then heat and melt the mixture, extrude it through an extruder, blow it into a film, cool and shape it, and then rotate and rewind it to obtain the intermediate layer milky white PE film; the die temperature of the extruder is 175℃, and the thickness of the intermediate layer milky white PE film is 45um by controlling the blown film pressure; in this raw material formula, titanium dioxide is a white masterbatch, and the raw material ratio can make the whiteness of the intermediate layer milky white PE film meet the standard and be thin and flat. While maintaining whiteness, the overall thickness of the composite sheet can be reduced, thereby improving the quality problems of blistering and edge swaying caused by excessive thickness.

[0038] S2. Flexographic printing of images and text on the inner surface of the outer PE film. The flexographic printing method is as follows: First, a high-adhesion ink is applied to a flexible resin printing plate using an anilox roller. Then, the flexible resin printing plate is bonded to the inner surface of the PE film. Finally, pressure is applied using an impression cylinder at a pressure of 0.4 MPa to transfer the image and text ink from the flexible resin printing plate to the PE film. (Refer to...) Figure 2 The flexible resin printing plate is composed of multiple staggered vertical graphic plates, specifically five. The impression cylinder spans the multiple vertical graphic plates of the flexible resin printing plate. The high-adhesion ink is Solimax series ink from D.E.S. Pigment Ltd. This flexible resin printing plate, which includes multiple staggered vertical graphic plates, can disperse the printing pressure of the impression cylinder, making the printing pressure uniform in all places. Combined with the high-adhesion ink, it can successfully overcome the problem of blurred edges of images when flexographic printing on PE film. Through the flexographic printing method of this application, the images printed on the inner surface of PE film are clear and not blurred.

[0039] S3. Combine the intermediate milky white PE film obtained in step S1 with the outer PE film printed with graphics in step S2 to form a semi-finished composite sheet structure of "outer PE film layer - flexographic ink layer - intermediate milky white PE film layer".

[0040] S4. The semi-finished composite sheet obtained in step S3 is sequentially laminated with an Al barrier film and an inner PE film using EAA adhesive to form a composite sheet structure of "outer PE film layer - flexographic ink layer - middle milky white PE film layer - first EAA adhesive layer - Al barrier film layer - second EAA adhesive layer - inner PE film layer".

[0041] The thicknesses of each layer of the resulting composite sheet are as follows: the outer PE film layer is 90 μm thick, the middle milky white PE film layer is 45 μm thick, the first EAA adhesive layer is 30 μm thick, the Al barrier film layer is 30 μm thick, the second EAA adhesive layer is 30 μm thick, and the inner PE film layer is 70 μm thick. This composite sheet meets the whiteness standard and has no quality issues such as bulging edges.

[0042] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Based on the present invention and the above description, those skilled in the art can make various changes and modifications without departing from the technical concept of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0043] Comparative Example 1

[0044] The pharmaceutical composite tube sheet used in this comparative example comes from the tube packaging of the typical product "Mayinglong Hemorrhoid Ointment". Its structure is "PE-INK-WPE-AL-EAA-PE". It is gravure printed on the outer transparent PE layer. In order to achieve sufficient whiteness, the middle milky white extruded WPE layer needs to be made very thick, and the thickness of the extruded WPE layer is 63um.

[0045] The composite flexible tube sheet has the following two problems: the use of gravure printing results in high ink costs (large ink application) and high plate-making costs; the excessively thick intermediate milky white extruded WPE layer causes the composite sheet to have a slight bulging edge quality problem.

[0046] Comparative Example 2

[0047] This comparative example demonstrates flexographic printing of images on PE film using a conventional flexible resin printing plate, see... Figure 3 The preparation methods for the remaining composite sheets are the same as in Example 1.

[0048] Conventional flexible resin printing plates: Each plate is aligned in parallel, and the printing pressure of the impression cylinder is concentrated on a horizontal line, which can lead to uneven local stress and printing defects.

[0049] The composite sheet products of the above embodiments and comparative examples were evaluated for appearance and quality in accordance with the standard requirements of "YBB00252005-2015 Polyethylene / Aluminum / Polyethylene Composite Pharmaceutical Ointment Tube", and the blue light whiteness of the products was measured on a WSD-3C fully automatic whiteness meter.

[0050] Table 1:

[0051]

[0052]

[0053] As can be seen from the comparison of the various embodiments and Comparative Example 1, in the manufacturing method of the composite sheet for pharmaceutical packaging in this application, the intermediate layer is replaced by the existing milky white extruded composite layer by using a milky white PE layer formed by blown film. The self-made intermediate milky white PE film layer has the required whiteness and is thin and flat. It can reduce the overall thickness of the composite sheet while maintaining the whiteness, thereby improving the quality problems of bubbling and edge swaying caused by excessive thickness.

[0054] As can be seen from the comparison between Example 1 and Comparative Example 2, the solution of this application, by using a flexible resin printing plate composed of multiple staggered vertical graphic plates and high-adhesion ink, can successfully overcome the problem of blurred edges of graphics in flexographic printing on PE film. Through the flexographic printing method described in this application, the graphics printed on the inner surface of the PE film are clear and not blurred, which can replace the traditional gravure printing method in composite sheets, thereby reducing the cost of plate making and the amount of ink used, achieving the purpose of economy and environmental protection.

Claims

1. A method for manufacturing a composite sheet for pharmaceutical packaging, characterized in that, Includes the following steps: S1. Preparation of intermediate layer milky white PE film: Mix 12-19 parts of LLDPE granules, 65-72 parts of LDPE granules, 12-18 parts of titanium dioxide and 0.6-1.2 parts of silica according to the following weight parts, then heat and melt, extrude through an extruder, blow film, cool and form, and rotate and rewind to obtain the intermediate layer milky white PE film. The thickness of the intermediate layer milky white PE film is 35-45um by controlling the blow film pressure. S2. Flexographic printing of images and text on the inner surface of the outer PE film; the flexographic printing method is as follows: first, a high-adhesion ink is applied to a flexible resin printing plate using an anilox roller; then, the flexible resin printing plate is bonded to the inner surface of the PE film; finally, pressure is applied by an impression cylinder to transfer the image ink from the flexible resin printing plate to the PE film; the flexible resin printing plate consists of multiple staggered vertical image plates, and the impression cylinder spans the multiple vertical image plates of the flexible resin printing plate; the high-adhesion ink is Solimax series ink from D.E. Color Co., Ltd. S3. Combine the intermediate milky white PE film obtained in step S1 with the outer PE film printed with graphics in step S2 to form a semi-finished composite sheet structure of "outer PE film layer - flexographic ink layer - intermediate milky white PE film layer". S4. The semi-finished composite sheet obtained in step S3 is sequentially laminated with an Al barrier film and an inner PE film using EAA adhesive to form a composite sheet structure of "outer PE film layer - flexographic ink layer - middle milky white PE film layer - first EAA adhesive layer - Al barrier film layer - second EAA adhesive layer - inner PE film layer".

2. The method for manufacturing a composite sheet for pharmaceutical packaging according to claim 1, characterized in that: In step S1, the weight percentages of the LLDPE granules are 15.4 parts, the weight percentages of the LDPE granules are 68.7 parts, the weight percentages of the titanium dioxide are 15 parts, and the weight percentages of the silica are 0.9 parts.

3. The method for manufacturing a composite sheet for pharmaceutical packaging according to claim 1, characterized in that: In step S1, the die temperature of the extruder is 175-195℃.

4. The method for manufacturing a composite sheet for pharmaceutical packaging according to claim 1, characterized in that: The pressure applied by the impression cylinder is 0.2-0.4 MPa.

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