Polyvinyl formal sponge fabric, preparation method therefor and application of polyvinyl formal sponge fabric

Abstract

The invention discloses a polyvinyl formal sponge fabric, a preparation method therefor and an application of the polyvinyl formal sponge fabric. The sponge fabric is polyvinyl formal sponge and is prepared from the following raw material ingredients in parts by mass: 80-150 parts of polyvinyl alcohol, 300-1,800 parts of water, 10-150 parts of formaldehyde or hexamethylene tetramine, 10-300 partsof hydrochloric acid or sulfuric acid and 0.01-3 parts of surfactant. According to the sponge, both porosity and pore rate are not lower than 85%, the average pore size is between 10 microns and 2mm,the degree of acetalization is 30% to 70%, and the sponge has the thickness of 0.5mm to 10cm and has the dry density of 0.05 to 0.12. According to the polyvinyl formal sponge fabric, the preparation method therefor and the application of the polyvinyl formal sponge fabric, the process is short in cycle, low in emission, low in energy consumption and high in product uniformity and can be used for carrying out continuous production; the obtained sponge fabric is integrated sponge with a three-dimensional open-pore structure, is air-permeable, fluffy, soft and comfortable, is free of fiber falling and has excellent liquid sucking characteristics; and the materials can be applied to filtering industry instead of the traditional filter media such as non-woven fabrics, Kraft paper and glass fibers.

Description

technical field [0001] The invention relates to a filter material or a medical dressing, in particular to a polyvinyl formal sponge cloth and its preparation method and application. Background technique [0002] The properties of polyvinyl formal are similar to cotton, and its strength and abrasion resistance are better than cotton. It has good durability, moisture absorption, warmth retention, abrasion resistance and sunlight resistance. The safety of polyvinyl formal sponge used in the medical field has been certified by the US FDA. PVA sponge has two kinds of production techniques at present, and the one, starch filling pore-forming method, as publication number is in documents such as CN101508747, CN101508814, CN1289629, with starch granules such as potato starch, cornstarch, wheat starch as filler, in polyvinyl alcohol After the formal is formed and matured, the residual starch is washed away with a large amount of water. The second is the gas foaming process. For ex...

AI Technical Summary

Problems solved by technology

For products produced by starch filling process, larger starch granules can be washed off in repeated cleaning processes such as beating, squeezing, shaking, tumbling, etc., but starch granules with a diameter of less than 2 microns are difficult to be cleaned by physical action, so , if there is starch residue in the PVA sponge, it will cause the following consequences: 1. Formaldehyde is blocked in the starch, causing the product to exceed the standard due to the formaldehyde carried by the starch

2. Increase the risk of mildew during product storage and transportation

3. Cause the product to turn yellow during the sterilization process

4. Cause the product to become hard, greatly reduce the wetting rate of the product, and reduce the liquid absorption rate and magnification of the product

5. When the product in the dry state encounters liquid, water can quickly enter the interior of the PVA molecular chain and combine with the hydroxyl groups on the chain to form hydrogen bonds, making the PVA molecular chain quickly open from a compact three-dimensional cross state to a stretched state. Here During the process, the opening rate of the molecular chains of starch granules is much slower than that of PVA molecular chains. Such a difference in speed causes the shedding and dissolution of starch granules, which greatly increases the contamination of blood and tissues and organs during clinical use. Lesion risk

[0005] However, traditional medical gauze is generally not used for infected wounds. It has no promoting effect on wound healing, has limited ability to manage exudate, adheres to the wound, re-damages the new epithelial tissue and causes bleeding, and causes pain after the patient changes the dressing.

[0006] At the same time, traditional medical gauze has disadvantages such as low absorption rate, slow absorption, incomplete absorption, unsatisfactory drainage effect, and loss of fluffy and elastic feeling after absorbing tissue exudate during operation.

Due to the large friction coefficient during use, it is not soft and comfortable enough, which increases the pain of the patient

In addition, traditional medical gauze is woven from cotton fibers, and there is a possibility of fiber falling off during use

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