Method of preparing hydrogel structure

1. A method of preparing hydrogel structure, wherein the hydrogel structure comprises:

(a) a one way penetrating polyurethane film layer,

(b) a hydrophobic pressure sensitive adhesive layer,

(c) a multi-directional elastic meltblown nonwoven,

(d) an interpenetrating polymer network, and

(e) a hydrophilic hydrogel;

and the method comprises:

(i) coating the hydrogel in a form of solution on the meltblown non-woven to form a product 1 ,

(ii) UV curing the product 1 in step (i), forming a composite comprising a hydrogel layer on the top, an interpenetrating polymer network in the middle, and a meltblown non-woven layer on the bottom, wherein the interpenetrating polymer network is a mixture of the hydrogel and the meltblown non-woven,

(iii) providing polyurethane film layer coated with pressure sensitive adhesive layer, and

(iv) laminating part of exposed fibers of meltblown non-woven with the pressure sensitive adhesive layer, forming a hydrogel structure.

2. The method of claim 1 , further comprises cutting the composite in step (ii).

3. The method of claim 1 , wherein the interpenetrating polymer network strengthens tension and adhesive ability for wound covering.

4. The method of claim 1 , wherein the hydrogel absorb excess moisture or wound tissue fluid to maintain proper skin moisture.

5. The method of claim 1 , wherein the hydrogel comprises:

(a) a monomer;

(b) a plasticizer;

(c) a photoinitiator;

(d) a cross-linking agent; and

(e) a thickener.

6. The method of claim 5 , wherein the monomer is acrylic amide monomer or acrylic sulfonate monomer.

7. The method of claim 6 , wherein the acrylic sulfonate monomer provides the hydrogel antiseptic effect.

8. The method of claim 5 , wherein the plasticizer is glycerol.

9. The method of claim 5 , wherein the thickener is glycerol.

10. The method of claim 8 , wherein the glycerol provides the hydrogel flexibility and increases the hydrophilicity.

11. The method of claim 5 , wherein the photoinitiator generates free radical and completes polymerization under 1 to 50 seconds of UV light irradiating.

12. The method of claim 5 , wherein the cross-linking agents are esters with unsaturated double functional groups.

13. The method of claim 5 , wherein posses weight ratios of the hydrogel are:

Acrylic amide monomer

15 to 30 units

Acrylic sulfonate monomer

10 to 50 units

Glycerol

15 to 45 units

Photoinitiator

0.01 to 0.1 units

Unsaturated double functional groups ester monomer

0.01 to 0.2 units.