Completely biodegradable food packing material and preparation method thereof

Abstract

The invention discloses a completely biodegradable food packing material and a preparation method thereof. The completely biodegradable material of plant fiber and starch is a product obtained by melting, blending and extruding potato starch, bamboo fiber, polycaprolactone, a plasticizer, an inorganic filling agent and a cross linker through a double-screw extruder; and the molten blend comprises the following components in parts by weight: 40 to 60 parts of potato starch, 10 to 30 parts of bamboo fiber, 5 to 10 parts of polycaprolactone, 2 to 10 parts of inorganic filling agent, 2 to 8 parts of cross linker, 5 to 20 parts of plasticizer and 2 to 10 parts of solubilizing agent. Compared with the traditional starch-based plastic degradable material, the tensile strength of the completely biodegradable material is improved by 20 to 40 percent; the stiffness is improved by 20 to 40 percent; the water absorption is reduced by 10 to 20 percent; and the completely biodegradable material has excellent properties of low cost, complete biodegradability and environmental friendliness, and can be widely used for packing food, particularly disposable instant snack boxes.

Description

technical field [0001] The invention relates to a completely biodegradable food packaging material and a preparation method. Background technique [0002] At present, most of the disposable fast food boxes used in large quantities are plastic products made of toxic additives, which not only affect human health, but also cause serious "white pollution" to the environment; a small amount of paper products are used, but the cost of paper products is high. One type of biodegradable material is starch, which will be decomposed into non-toxic CO by microorganisms in the natural environment. 2 and H 2 O, but the starch molecular chain contains a large number of hydroxyl groups, which are easy to form hydrogen bonds inside and outside the molecular chain, so it is insoluble, difficult to melt, and has poor water resistance. It is easy to absorb water when it meets water or in humid air for a long time. It is stable There is also plant fiber, such as peanut shells, waste paper powd...

AI Technical Summary

Problems solved by technology

[0002] At present, most of the disposable fast food boxes used in large quantities are plastic products made of toxic additives, which not only affect human health, but also cause serious "white pollution" to the environment; a small amount of paper products are used, but the cost of paper products is high. One type of biodegradable material is starch, which will be decomposed into non-toxic CO by microorganisms in the natural environment. 2 and H 2 O, but the starch molecular chain contains a large number of hydroxyl groups, which are easy to form hydrogen bonds inside and outside the molecular chain, so it is insoluble, difficult to melt, and has poor water resistance. It is easy to absorb water when it meets water or in humid air for a long time. It is stable There are also plant fibers, such as peanut shells, waste paper powder, wheat straw, wood chips, bamboo fibers, etc.

The addition of plant fibers provides a certain mechanical strength, which is conducive to improving the biodegradability of the material; but its water resistance is also limited, and it is easy to absorb moisture in humid air for a long time, thereby reducing its mechanical strength and affecting the quality and effect of packaging; Fully biodegradable materials are too expensive