Medical polyurethane foam dressing and preparation method thereof

A preparation method of medical polyurethane foam dressing, comprising:

• step 1, preparing a polyurethane film, which comprises:
• coating PU/TPU resin on a release film material, with a coating amount of 15 to 30 g/m2, which is dried to obtain a polyurethane film with a thickness of 15 to 18 μm;
• and then performing a corona treatment with a corona value of 1 to 4 A and a running speed of 5 to 10 m/min, so that surface roughness of the polyurethane film after the corona is 9 to 10;
• step 2, preparing hydrophilic polyurethane foam, in which:
• a formula of the hydrophilic polyurethane foam is made in parts by weight, which comprises:
• 60 to 87.5 parts of isocyanate prepolymer, 12 to 36 parts of water, 0.16 to 2.8 parts of surfactant and 0.34 to 1.2 parts of sodium bicarbonate;
• and
• mixing the formula, the isocyanate prepolymer and a aqueous phase substance which consists of the water, the surfactant and the sodium bicarbonate are stirred separately, with a stirring temperature of the isocyanate prepolymer of 25 to 35° C. and a stirring temperature of the aqueous phase substance of 15 to 25° C.;
• a low-pressure foaming mixer is adopted to mix the isocyanate prepolymer and the aqueous phase substance at a rotating speed of 5,000 r/min, and pouring is carried out by connecting a conical plastic pouring head, and a discharging size and diameter of the pouring head is adjusted according to a flow rate;
• mixed materials are poured on a running polyurethane film, which is covered with a release paper, and a surface of the release paper is coated with a surface coating, which is a silicon layer or a polymer material layer;
• mixed liquid poured on the release paper is leveled by an upper pressing plate and a lower pressing plate, which is then cured at a room temperature for 7 to 10 minutes, and then dried in an oven, and the dried polyurethane foam is the polyurethane foam of a composite single-sided waterproof and breathable polyurethane film;
• step 3, providing a soft silicone composite layer, in which
• the soft silicone composite layer is compounded with the hydrophilic polyurethane foam layer, with a compounding pressure range of 5 to 7 KPa and a running speed of 5 to 8 m/min, a through hole being defined on the soft silicone composite layer;
• and
• step 4, cutting, molding, packaging and sterilizing the manufactured polyurethane foam dressing so as to obtain the medical polyurethane foam dressing.