Shijiazhuang Asa Technology Co., Ltd. , https://www.asaantiwrinkle.com
Taking into account that "white pollution" is mainly visual pollution, that is to say that the discarded plastic bags are always exposed to the natural environment. Therefore, we consider that the product should have both photodegradation and biodegradation in terms of performance design. The nature, in turn, can achieve the effect of complete degradation. 
The principle of degradation is that when plastic materials or products are exposed to sunlight, air, and moisture, a series of chemical changes can occur. Among them, the degradation of macromolecules in plastics mainly involves Norrish photochemical reactions. 
In this photochemical reaction, there are mainly two groups of products. The first group is a radical species that generates two small molecules. The second group mainly produces a methyl ketone-containing material and a terminal vinyl group-containing material. 
If the above two substances continue to be exposed to outside sunlight, air, and humidity conditions, it will be further degraded into small molecular weight ketones, acids, esters, aldehydes and other substances, which are easily used by microorganisms and released. CO2 and H2O achieve the effect of complete degradation. 
We also added a variety of biomasses that increase microbial activity in our bagged compound system. In this way, the degraded substances of small molecules can be more easily used by microorganisms to achieve the effect of assimilation with the environment. 
Test raw materials:
The base trees refer to HDPE (High Density Polyethylene), L-LDPE (Linear Low Density Polyethylene), LDPE (Low Density Polyethylene), PP (Polypropylene), and photo-biodegradable masterbatches. 
Processing conditions: 
Film blowing machine: screw diameter 50mm
L/D=26
Screw speed 160 rpm (ZK)〗 
Extrusion section temperature: 
The fuselage I section 150 °C II section 170 °C 
200°C machine head 200～210°C
Blow up ratio: 3.5 to 4.1 inches
Change in appearance
Samples of plastic shopping bags were placed on an exposure rack (wooden frame with a 40° angle facing the ground to the ground), and changes in the appearance of the samples were observed. 
When the sample was exposed outdoors for more than 20 days (cumulative radiation was 300 MJ/2), cracks and cracks occurred; 30 to 40 days were crushed or even powdery; about 60 to 80 days disappeared from the sensation. In addition, we have also developed a biodegradable bag that has a faster degradation effect. It breaks in more than 10 days and appears powdery for more than 20 days. It can disappear from the sensory perception in about 30 days. 
Change in chemical structure
When the degradable plastic bag is exposed outdoors for 20 to 35 days (the cumulative radiation is about 300 to 400 MJ/m 2 ), the use of an infrared absorption spectrometer to detect the degradation bag membrane clearly shows that the chemical structure has undergone significant changes. 
Degradation of polyethylene bags produces large amounts of oxygenates. Specifically speaking, the macromolecules of degraded plastics become ketones, aldehydes, acids, and esters of many small molecules. 
China Academy of Agricultural Sciences has used 1600 times the microscope to observe the degradation of debris, you can clearly see that a large number of fungi, bacteria and mycelium attached to the surface of the degradation debris. This shows that in the later stages of degradation, biodegradation can completely make it harmless, and it can be assimilated with the soil and absorbed by the environment. 
Another important test item for judging the degradation effect of degradable plastics is the decrease in molecular weight and the rate of reduction. After a 30 to 40-day exposure to the sun (the cumulative solar radiation is about 450 MJ/m2), the weight-average molecular weight drop is very significant. The reduction rate reached 89 to 95.6%. This photo-biodegradable plastic bag has a very good degradation effect. 
The photo-biodegradable masterbatch is added to a general-purpose polyethylene tree finger in a certain ratio to produce a degradable plastic bag with a very good degradation effect. This kind of photo-biodegradable plastic bag is a good substitute for common used bags and shopping bags, which can greatly reduce the "white pollution" troubles and harms. (Han Changtai has outstanding contributions to national experts, professor-level senior engineer)
Photo-biodegradable plastic bag degradation effect experiment
Due to the disposable plastic shopping bags used in the market, it is basically a general-purpose polyolefin resin made of HDPE, LLDPE, and LDPE. These trees refer to raw materials, because of their low price, easy processing and molding, high strength, and excellent sanitation. Therefore, it is a good material for making various shopping bags. However, due to the structural stability of this type of material, it is difficult to degrade, and if it is littered after use, it will cause “white pollutionâ€. 