Integrated solvent-free process for the production of PVC tape

Abstract

This disclosure relates to a solventless preparation method for preparing polyvinyl chloride (PVC) tape, comprising the following steps: (1) forming an aqueous primer layer on a PVC film layer; (2) forming granular natural rubber by kneading and crushing natural rubber raw materials; (3) preparing the granular natural rubber into a solventless hot melt pressure-sensitive adhesive; and (4) coating the solventless hot melt pressure-sensitive adhesive onto the aqueous primer layer, wherein the aforementioned steps (1) to (4) are performed on a single continuous production line.

Claims

1. A solvent-free preparation method for preparing polyvinyl chloride (PVC) tape, comprising the following steps: (1) forming an aqueous primer layer on a PVC film layer; (2) forming granular natural rubber by kneading and crushing natural rubber raw materials; (3) preparing the granular natural rubber into a solvent-free hot melt pressure-sensitive adhesive; and (4) coating the solvent-free hot melt pressure-sensitive adhesive onto the aqueous primer layer, wherein the aforementioned steps (1) to (4) are performed on a single continuous production line; and wherein the solvent-free preparation method further comprises a cooling step, wherein the cooling section in the coating section path accounts for 20-40% of the overall film material travel path length.

2. The solvent-free preparation method of claim 1, wherein the length, height and / or width of the granular natural rubber are in the range of 0.5 to 1.5 cm.

3. The solvent-free preparation method of claim 1, wherein step (2) further comprises adding an anti-sticking agent to the granular natural rubber after kneading and crushing.

4. The solvent-free preparation method of claim 3, wherein the anti-sticking agent comprises zinc stearate.

5. The solventless preparation method of claim 1 further includes the following steps: (5) refluxing the solventless hot melt pressure-sensitive adhesive residue from step (4) back to the adhesive preparation process in step (3).

6. The solventless preparation method of claim 5, wherein step (5) comprises single-screw mixing of the solventless hot melt pressure-sensitive adhesive residue.

7. The solvent-free preparation method of claim 6, wherein the temperature of the single-screw compounding is in the range of 140~180°C.

8. The solvent-free preparation method of claim 1, wherein step (3) comprises twin-screw compounding of the granular natural rubber.

9. The solventless preparation method of claim 5, wherein the mass flow rate of the solventless hot melt pressure-sensitive adhesive residue returning to the adhesive preparation process in step (3) is 5 to 10% of the mass flow rate of the solventless hot melt pressure-sensitive adhesive flowing out of the mixer in step (3).

10. The solventless preparation method of claim 1 further includes a thickness measurement step after the cooling step, wherein the parameters of the coating head in step (4) are adjusted by using a thickness gauge to provide feedback on the thickness distribution in order to ensure the uniformity of the thickness of the solventless hot melt pressure-sensitive adhesive on the water-based primer.

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