Preparation and processing technology of waterborne polyurethane film

Abstract

The invention belongs to the technical field of new materials, and particularly relates to a preparation and processing technology of a waterborne polyurethane film. The preparation and processing technology comprises the following steps: step 1, coating of waterborne polyurethane: uniformly coating a flat base material with the waterborne polyurethane; step 2, drying to form a thin film sheet: heating and drying the waterborne polyurethane on the base material to form the thin film sheet with uniform thickness; step 3, polyurethane film rolling: rolling the dried waterborne polyurethane filmsheet, wherein the process of coating of the waterborne polyurethane in the step 1 is completed by adopting a waterborne polyurethane film preparation and processing device. According to the invention, when the surface of a substrate is coated with the waterborne polyurethane, a conveying mechanism supplies materials at a constant speed, the waterborne polyurethane coating the surface of the substrate is in a continuous and non-overlapped state, so the waterborne polyurethane is prevented from being gathered on the surface of the base material; and transverse trowelling can be conducted on thewaterborne polyurethane, so the uniformity of the thickness of the dried film is improved.

Description

technical field [0001] The invention belongs to the technical field of new materials, and in particular relates to a preparation and processing technology of a water-based polyurethane film. Background technique [0002] Water-based polyurethane is a new type of polyurethane system that uses water instead of organic solvents as the dispersion medium, also known as water-dispersed polyurethane, water-based polyurethane or water-based polyurethane. Water-based polyurethane uses water as a solvent, which has the advantages of no pollution, safety and reliability, excellent mechanical properties, good compatibility, and easy modification. Water-based polyurethane becomes a thin film after coating and drying, which has air permeability, proper strength and good elasticity, so it is widely used in medical and health, clothing fabrics and other fields. In the process of preparing water-based polyurethane in the prior art, there are the following problems in the process of applying...

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Problems solved by technology

[0004] The invention provides a water-based polyurethane film preparation and processing technology, the purpose is to solve the following problems in the process of coating the water-based polyurethane on the surface of the substrate in the process of preparing the water-based polyurethane: (1) when the water-based polyurethane is coated longitudinally , the coating roller needs to be moved laterally after each coating, and it is difficult to accurately control the moving distance of the coating roller during the lateral movement; if the lateral movement distance is too large, there will be a gap between two longitudinal coatings, resulting in The water-based polyurethane on the surface of the substrate is discontinuous, which leads to the discontinuity of the film after drying; if the lateral movement distance is too small, there will be overlapping between the two longitudinal coatings, resulting in partial overlapping of the water-based polyurethane on the surface of the substrate. And then cause the film thickness after drying to be uneven; (2) when water-based polyurethane is carried out longitudinal coating, water-based polyurethane receives the pressure of coating roller and can gather to both sides of coating roller, causes the thickness of water-based polyurethane on substrate surface to be uneven. (3) when the coating roller coats the surface of the substrate with water-based polyurethane, it is difficult to control the constant speed of feeding the coating roller, resulting in the thickness of the water-based polyurethane on the surface of the substrate Uneven, which in turn leads to uneven film thickness after drying

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