There are many grades of PVC. The viscosity or K value commonly used in the industry indicates the average molecular weight (or average degree of polymerization) of PVC, that is, the length of the PVC molecular chain, which determines the grade of the resin and the corresponding processing parameters. The molecular weight of the resin is related to the physical and mechanical properties of the product.
PVC used to be the largest general-purpose plastic in the world, and it is widely used. It is widely used in construction materials, industrial products, daily necessities, floor leather, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foam materials, sealing materials, fibers, etc
SG3 (K-70, S1300): mostly used for soft products, hoses, wires and cables, films, shoe materials, toys, auto parts etc.
PVC RESIN SG3 has high purity, less fish eyes, easy to blister, high temperature resistance, insulation, soft product texture, etc. It is mainly used to produce soft products such as wires and cables, agricultural films, conveyor belts, and daily plastic products.
PVC RESIN SG3,Pvc Resin Sg3 Sg5 Sg8,Pvc Resin K70,Pvc Resin Powder Sg3,Suspension Pvc Resin Sg3 Henan Shunbang Chemical Industry CO.,Ltd , https://www.suspensionpvc.com
It is understood that in the face of pollution in river waters, soils in some areas of China are also polluted to varying degrees, posing a threat to the ecological environment, food safety and sustainable agricultural development. According to incomplete investigations, there are currently about 150 million acres of arable land in China, 32.5 million acres of polluted arable land for sewage irrigation, and 2 million acres of land for solid waste storage, which together account for about 1/10 of the total area of ​​arable land. .
At present, the main causes of soil pollution in China are:
Indiscriminate application of fertilizers and pesticides. Calculated according to the amount of cultivated land, the use of chemical fertilizers in China reaches 40 tons per square kilometer, far exceeding the safety upper limit per unit area set by developed countries to prevent chemical fertilizers from harming the soil and water bodies.
Plastic film flooding. In the past 20 years, China has occupied the top place in the world for the amount of plastic film and its coverage area. According to a survey conducted by the Environmental Protection Bureau of Zhejiang Province, the average residue of plastic film in the surveyed area was 3.78 tons/km2, resulting in a production loss of about 20% of the output value. With the progress of agricultural modernization in the Midwest, this type of pollution is also common in the main grain production areas in the central and western regions.
Oil, solid liquid waste and other organic materials leaked.
It is understood that the main contents of this survey include: Soil environmental risk assessment based on soil environmental risks by analyzing the contents of heavy metals, pesticide residues, organic pollutants, and soil physicochemical properties in the soil, combining land use types and soil types. . In addition, the risk assessment and safety classification of soil pollution in key regions were carried out. The investigation focused on the environmental hot spots around the heavily polluting enterprises, industrial legacy or abandoned sites, solid waste disposal and disposal sites, oil fields, and mining areas, and identified the type, scope, extent of soil pollution, and the spatial distribution of soil heavy pollution areas. , analyze the causes of pollution.
According to another report, the Soil Pollution Prevention Law is being drafted.
PVC Resin is a kind of non-crystalline linear polymer compound. The larger the relative molecular mass, the higher the viscosity, the higher the molecular weight, and the higher the tensile strength, impact strength, and elastic modulus of the product, but the flow of the resin melt Decline in sex and plasticity. The viscosity number is usually used to indicate the molecular weight of the polymer, and the polymer model is divided
The country invests a lot of money for the first time to carry out a special survey on soil pollution and prevention The chemical industry is facing a new round of “environmental protection stormsâ€
The reporter learned from the National Soil Pollution Survey and the Special Conference on Pollution Prevention and Control held in Beijing on July 18th that the National Environmental Protection Administration and the Ministry of Land and Resources have jointly undertaken the national soil pollution that lasted three and a half years and invested 1 billion yuan. The system investigation has entered the implementation stage. The survey aims to identify soil pollution caused by organic matter in key areas in order to establish soil pollution prevention laws and regulations and standards system. Experts in the industry have warned that this means that the chemical industry that has just undergone environmental pollution inspections in rivers and waters across the country will face the “environmental protection storm†of soil pollution.