Rhombic embossed film and preparation method thereof

Abstract

The invention belongs to the field of thin films, and particularly relates to a rhombic embossed film and a preparation method thereof.The preparation method of the rhombic embossed film comprises the following steps that S1, raw materials are in a casting molten state after being heated and sheared through a machine barrel screw, then extruded through a T-shaped flat seam die head and attached to a pre-shaping roller to form a thin film to be cooled, the to-be-cooled film is cooled after passing through the fan and the primary shaping roller and forms a primary film; and S2, the primary film sequentially passes through a preheating roller pair, a deep embossing roller pair and a secondary shaping roller to finish secondary embossing, and a rhombic embossed film is formed. The transparency of the rhombic embossed film is improved by adopting a method of primary shaping and secondary embossing, and the shaping effect of the rhombic embossed film is improved and lines are easy to strip by adopting a method of reducing the preheating temperature, changing the film penetrating direction and changing the surface lines of the deep embossing roller; the produced rhombic embossed film is high in transparency, obvious in lines and free of curled edges and vertical lines.

Description

Technical Field

[0001] The invention belongs to the field of films, and in particular relates to a diamond embossed film and a preparation method thereof. Background Art

[0002] Diamond embossed film is used on cooling patches. The film protects the drug layer by contacting it. Therefore, the film is required to have a high barrier effect. While blocking the penetration of the drug layer, it must also have a good release effect. When peeling off the film, the peeling force generated is small, and no drug residue is left.

[0003] The existing production technology generally adopts a one-time film forming method to produce diamond embossed films, that is, the film forming and embossing processes are carried out simultaneously. However, the diamond embossed films formed by this method have a high haze and the transparency cannot meet the requirements. Summary of the Invention

[0004] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a diamond embossed film and a preparation method thereof. The transparency of the diamond embossed film is improved by adopting the method of one-time shaping and secondary embossing, and the shaping effect of the diamond embossed film is improved and the lines are easy to peel off by lowering the preheating temperature, changing the film penetration direction, and changing the surface texture of the deep embossing roller. The produced diamond embossed film has high transparency, obvious texture, and no curling and vertical lines.

[0005] The specific technical solution adopted in the present invention is:

[0006] A diamond embossed film comprising, by weight, 80-95 parts of homopolypropylene and 5-20 parts of linear polyethylene with 4C side groups;

[0007] Among them, the density of homopolymer polypropylene is 0.9-0.91g / cm 3 , melt index is 1.5-3;

[0008] The density of linear polyethylene with 4C side groups is 0.92-0.93 g / cm 3 , the melt index is 2-3.

[0009] A method for preparing a diamond embossed film comprises the following steps:

[0010] S1, the raw material is heated and sheared by the barrel screw to form a cast molten state, then extruded through a T-type flat die and attached to a pre-setting roller to form a film to be cooled. The film to be cooled is cooled by a fan and a primary setting roller to form a primary film;

[0011] S2. The primary film passes through the preheating roller, deep embossing roller, and secondary shaping roller in sequence to complete the secondary embossing and form a diamond embossed film.

[0012] Furthermore, the preheating temperature of the preheating roller is 60-70°C.

[0013] Furthermore, the deep embossed roller pair includes a deep embossed flower roller and a deep embossed rubber roller. The deep embossed flower roller is formed into diamond patterns by means of raised lines that are distributed horizontally and vertically. The diamond area formed by the intersection of the raised lines is concave, and the surface of the deep embossed rubber roller is smooth.

[0014] Furthermore, the raised lines are trapezoidal in structure, the top width of the raised lines is 0.22-0.25 mm, the bottom width of the raised lines is 0.55-0.65 mm, and the concave depth of the diamond-shaped area relative to the top of the raised lines is 0.35-0.45 mm.

[0015] Furthermore, the temperature of the deep embossing roller is 105-115°C.

[0016] Furthermore, the pressure of the deep embossing rubber roller is 6 MPa.

[0017] Furthermore, the equipment used for the secondary embossing also includes a flattening roller and a guide roller. The primary film is flattened along the bottom of the flattening roller and then passes through a preheating roller. The primary film preheated by the preheating roller passes from top to bottom through the gap between the deep embossing roller and the deep embossing rubber roller with the help of the guide roller. The primary film extends along the bottom of the deep embossing roller to the secondary shaping roller for cooling and shaping to form a diamond embossed film.

[0018] The beneficial effects of the present invention are:

[0019] 1. The present invention improves the transparency of the diamond embossed film by adopting a method of one-time shaping and two-time embossing. However, since this method will produce shallow lines, poor shaping effect and difficult line peeling, the shaping effect of the diamond embossed film is improved and the lines are easy to peel off by lowering the preheating temperature, changing the film penetration direction, and changing the surface texture of the deep embossing roller. The produced diamond embossed film has high transparency, obvious texture, and no curling or vertical lines.

[0020] 2. The film penetration direction of the present invention causes the film to be subjected to greater tension during the embossing process, reducing the blurring of the lines caused by film rebound or relaxation, thereby making the lines of the produced diamond embossed film more obvious.

[0021] 3. The lines on the deep embossed roller of the present invention are convex, and the diamond-shaped area is concave. During production, the concave diamond-shaped area forms an "inverted" structure after cooling. Since the material deforms toward the rubber roller when shrinking, the actual demoulding resistance is small, so the mechanical bite force during peeling is weak, making it easy to peel.

[0022] In addition, the raised lines directly extrude the film material, forcing the molten material into the concave diamond area, filling it more fully, making the texture of the diamond embossed film clearer and more obvious. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is the film forming path of the diamond embossed film in the present invention;

[0024] Figure 2 This is an example of the texture of the diamond embossed film of the present invention;

[0025] Figure 3 is the film penetration direction of the film in Comparative Examples 1-6;

[0026] Figure 4 Schematic diagram of the surface texture of the deep embossing roller in Comparative Example 7;

[0027] Figure 5 This is an example of the texture of the diamond embossed film in Comparative Example 7; DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to the accompanying drawings and specific embodiments: 1. Specific embodiments

[0030] Example 1

[0031] A method for preparing a diamond embossed film, comprising the following steps:

[0032] S1, the raw material is heated and sheared by the barrel screw to form a cast molten state, then extruded through a T-type flat slot die and attached to a pre-setting roller to form a film to be cooled. The film to be cooled is first cooled by a fan, and then cooled by a primary setting roller and a fan at the same time. After cooling, the primary setting is completed and formed into a primary film;

[0033] The linear speed ratio during extrusion is 1.063, the interior of the primary shaping roller is filled with circulating water cooling medium, and the water inlet temperature of the primary shaping roller is 30°C;

[0034] S2, the primary film is flattened along the bottom of the flattening roller and then passes through the preheating roller. The primary film preheated by the preheating roller passes through the gap between the deep embossing roller and the deep embossing rubber roller from top to bottom with the help of the guide roller. The primary film extends along the bottom of the deep embossing roller to the secondary shaping roller for cooling and then completes the secondary embossing to form a diamond embossed film. The secondary embossing direction of the diamond embossed film is as follows: Figure 1 As shown, the surface texture of the membrane is as follows Figure 2 As shown;

[0035] Among them, the preheating roller temperature is: 90℃, the deep embossing roller temperature is: 110℃, the deep embossing rubber roller pressure is: 6MPa, the interior of the secondary shaping roller is filled with circulating water cooling medium, and the water inlet temperature of the secondary shaping roller is 40℃;

[0036] The top width of the raised line is 0.24 mm, the bottom width of the raised line is 0.6 mm, and the concave depth of the diamond-shaped area relative to the top of the raised line is 0.4 mm.

[0037] Example 2

[0038] The only difference between Example 2 and Example 1 is that the temperature of the preheated roller in Example 2 is 65°C.

[0039] Example 3

[0040] The only difference between Example 3 and Example 1 is that the temperature of the preheated roller in Example 3 is 50°C.

[0041] Comparative Example 1

[0042] A method for preparing a diamond embossed film, comprising the following steps:

[0043] S1, the raw material is heated and sheared by the barrel screw to form a cast molten state, then extruded through a T-type flat slot die and attached to a pre-setting roller to form a film to be cooled. The film to be cooled is first cooled by a fan, and then cooled by a primary setting roller and a fan at the same time. After cooling, the primary setting is completed and formed into a primary film;

[0044] The water inlet temperature of the primary shaping roller is 30℃;

[0045] S2, the primary film is flattened along the bottom of the flattening roller and then passes through the preheating roller. The primary film preheated by the preheating roller passes through the gap between the deep embossing roller and the deep embossing rubber roller from top to bottom with the help of the guide roller. The primary film extends along the top of the deep embossing roller to the secondary shaping roller for cooling and then completes the secondary embossing to form a diamond embossed film. The secondary embossing direction of the diamond embossed film is as follows: Figure 3 As shown;

[0046] Among them, the preheating roller temperature is: 90℃, the deep embossing roller temperature is: 110℃, the deep embossing rubber roller pressure is: 6MPa, and the water inlet temperature of the secondary shaping roller is 40℃;

[0047] The top width of the raised line is 0.3 mm, the bottom width of the raised line is 0.8 mm, and the concave depth of the diamond-shaped area relative to the top of the raised line is 0.15 mm.

[0048] Comparative Example 2

[0049] The only difference between Comparative Example 2 and Comparative Example 1 is that the pressure of the deep embossing rubber roller in Comparative Example 2 is 8 MPa.

[0050] Comparative Example 3

[0051] The only difference between Comparative Example 3 and Comparative Example 1 is that the preheating roller temperature in Comparative Example 3 is 80°C.

[0052] Comparative Example 4

[0053] The only difference between Comparative Example 4 and Comparative Example 1 is that the preheating roller temperature in Comparative Example 4 is 65°C.

[0054] Comparative Example 5

[0055] The only difference between Comparative Example 5 and Comparative Example 1 is that the preheating roller temperature in Comparative Example 5 is 50°C.

[0056] Comparative Example 6

[0057] The only difference between Example 6 and Example 1 is that the top width of the raised lines on the deep embossing roller in Example 6 is 0.24 mm, the bottom width of the raised lines is 0.6 mm, and the concave depth of the diamond area relative to the top of the raised lines is 0.6 mm.

[0058] Comparative Example 7

[0059] The only difference between Comparative Example 7 and Example 1 is that the lines on the deep embossing roller in Comparative Example 7 are concave, the diamond-shaped area is convex, and the lines on the deep embossing roller are as follows: Figure 4 As shown, the pressed texture is as Figure 5 As shown;

[0060] The concave depth of the line is 0.14 mm, the cross-section of the line is an inverted triangle, and the width of the top of the line is 0.3 mm.

[0061] 2. Performance Testing

[0062] The diamond embossed films prepared in Examples 1-3 and Comparative Examples 1-7 were subjected to performance tests, wherein the transparency test was to measure the transmittance of direct light. The higher the value, the higher the direct light transmittance, indicating that the transparency of the product is better.

[0063] The test results are shown in Table 1.

[0064] Table 1

[0065]

[0066] It can be seen from Table 1 that the process of Example 2 is the best, and Examples 1 and 3 have different problems because the preheating temperature is too high or too low.

[0067] The present invention improves the transparency of the diamond embossed film by adopting a method of one-time shaping and two-time embossing, and improves the shaping effect of the diamond embossed film and makes the lines easy to peel off by lowering the preheating temperature, changing the film penetration direction, and changing the surface texture of the deep embossing roller. The produced diamond embossed film has high transparency, obvious texture, and no curling or vertical lines.

Claims

1. A diamond embossed film, characterized in that: Calculated by weight, it comprises 80-95 parts of homopolymer polypropylene and 5-20 parts of linear polyethylene with 4C side groups; Among them, the density of homopolymer polypropylene is 0.9-0.91g / cm 3 , melt index is 1.5-3; The density of linear polyethylene with 4C side groups is 0.92-0.93 g / cm 3 , the melt index is 2-3.

2. The method for preparing a diamond embossed film according to claim 1, characterized in that: The preparation method comprises the following steps: S1, the raw material is heated and sheared by the barrel screw to form a cast molten state, then extruded through a T-type flat die and attached to a pre-setting roller to form a film to be cooled. The film to be cooled is cooled by a fan and a primary setting roller to form a primary film; S2. The primary film passes through the preheating roller, deep embossing roller, and secondary shaping roller in sequence to complete the secondary embossing and form a diamond embossed film.

3. The method for preparing a diamond embossed film according to claim 2, wherein: The preheating temperature of the preheating roller is 60-70°C.

4. The method for preparing a diamond embossed film according to claim 2, wherein: The deep embossed roller pair includes a deep embossed flower roller and a deep embossed rubber roller. The deep embossed flower roller is formed into diamond patterns by means of raised lines that are distributed horizontally and vertically. The diamond areas formed by the intersection of the raised lines are concave. The surface of the deep embossed rubber roller is smooth.

5. The method for preparing a diamond embossed film according to claim 4, wherein: The raised lines are in a trapezoidal structure, the top width of the raised lines is 0.22-0.25 mm, the bottom width of the raised lines is 0.55-0.65 mm, and the concave depth of the diamond-shaped area relative to the top of the raised lines is 0.35-0.45 mm.

6. The method for preparing a diamond embossed film according to claim 4, characterized in that: The temperature of the deep embossing roller is 105-115°C.

7. The method for preparing a diamond embossed film according to claim 4, characterized in that: The pressure of the deep embossing rubber roller is 6 MPa.

8. The method for preparing a diamond embossed film according to claim 4, characterized in that: The equipment used for the secondary embossing also includes a flattening roller and a guide roller. The primary film is flattened along the bottom of the flattening roller and then passes through a preheating roller. The primary film preheated by the preheating roller passes from top to bottom through the gap between the deep embossing roller and the deep embossing rubber roller with the help of the guide roller. The primary film extends along the bottom of the deep embossing roller to the secondary shaping roller for cooling and shaping to form a diamond embossed film.

Images