Method for manufacturing fruit and vegetable humidity-adjusting fresh-keeping film

Abstract

The invention discloses a method for manufacturing a fruit and vegetable humidity-adjusting fresh-keeping film. Body paper is prepared through papermaking by means of plant fiber as the raw material and by adding a proper wet strength agent and a proper dry strength agent. The body paper is prepared into the humidity-adjusting fresh-keeping film by coating a mixed glue solution composed of a hydrophilic water-retention natural high-molecular polymer and a water-insoluble, safe and environment-friendly mildew-proof antibacterial agent. The manufacturing method is environmentally friendly and simple, and the special humidity-adjusting fresh-keeping film is used for a fruit and vegetable box with a fresh-keeping function and a refrigerator with the fresh-keeping fruit and vegetable box. The fruit and vegetable humidity-adjusting fresh-keeping film can make fruits and vegetables in the fruit and vegetable box hold moisture and kept fresh when relative humidity is small, moisture permeability is remarkably increased when relative humidity is large, and condensation and rotting are prevented. The humidity-adjusting fresh-keeping film can be completely and naturally degraded.

Description

technical field [0001] The invention relates to the technical field of fruit and vegetable fresh-keeping and the technical field of special paper, in particular to the technical field of production of a paper film for regulating humidity and keeping fresh of fruits and vegetables in a refrigerator freezer or a fruit and vegetable box. Background technique [0002] Fresh fruits and vegetables are fresh foods with high water content, and they can still continue to carry out life activities such as breathing and transpiration after picking. During the storage of fruits and vegetables, the consumption of water and nutrients is directly proportional to the intensity of respiration of fruits and vegetables. Losing water is equivalent to losing freshness and weight. Therefore, reducing water loss and inhibiting respiration are important links in fruit and vegetable storage. [0003] In order to prolong the freshness period of fruits and vegetables in the refrigerator, existing tech...

AI Technical Summary

Problems solved by technology

Generally, "temperature-sensitive and moisture-permeable film" uses nylon or polyester as the base material, and its moisture-permeability can respond to temperature, but it does not respond to changes in humidity. Therefore, when the relative humidity is above 90%, the temperature-sensitive and moisture-permeable film The film itself will generate condensation, especially when it is placed on the fruit and vegetable box of the refrigerator, and it is placed in a low-temperature environment, it is also prone to condensation

Although the Siemens silicon filter membrane has moisturizing properties, its moisture permeability cannot change with temperature and humidity

"Moisture-sensitive and moisture-permeable film" is to apply viscose solution on the paper-based substrate, and obtain a moisture-sensitive and moisture-permeable film through sulfuric acid acid precipitation regeneration and a series of subsequent purification processes, although the moisture-permeable film produced by this method The wet film has the characteristic that the moisture permeability increases with the increase of humidity, but there are several problems in the preparation of the moisture-sensitive moisture-permeable film by this method: First, the production process is complicated and the equipment investment is large

The second is that the production process has high requirements on water quality and equipment. Deionized water is used throughout the process, and the water consumption is very large. The equipment needs to be resistant to corrosion by acids, alkalis, and carbon disulfide.

Third, the investment in environmental protection facilities is large and the risk of pollution is high

The regeneration process of regenerated cellulose has high pollution risks such as air pollution, water pollution, and residual chlorine

Due to the use of carbon disulfide in the preparation of viscose liquid, a part of carbon disulfide will exist in a free state, and the side reaction in the xanthate regeneration process will generate hydrogen sulfide. These toxic substances pose a severe test to the production site environment and air pollution prevention and control; In the production process, a large amount of washing waste liquid after acid analysis, washing waste liquid after alkali desulfurization and bleaching waste liquid will also be produced, and there are problems in the treatment of a series of washing waste liquid; the bleaching liquid used in the bleaching process Generally, it is sodium hypochlorite. If the subsequent washing is not thorough, there will be a problem of excessive chloride ion content, which is a major taboo for food paper.

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