Three high two low” polypropylene PP.”

“Three high and two low” polypropylene (High Melt Index, High Modulus, high impact resistance, low odor, low VOC) is one of the most important varieties of PP, which has excellent mechanical properties, chemical stability, creep resistance and other advantages, the utility model can prepare large thin-wall products and save raw materials, and is widely used in the fields of automobiles, home appliances and the like.

With the rapid development of automobile industry, home appliance industry, logistics industry and electronic telecommunication industry, the market of“Three high and two low” polypropylene will be bigger and bigger.

1. High melting point

Melt flow rate MFR ≥30g/10min, generally there are 30,40,50,60,100,110,120, high melt index can meet the needs of large-scale products and high-speed injection molding. The improvement of fluidity can reduce the processing temperature, injection pressure, die-closing force and so on, thus reducing energy consumption, shortening the molding cycle of the product, and greatly increasing the product output, can meet the needs of large-scale products and high-speed injection molding. In addition, the use of high-flow polypropylene can be injection molded thin-walled products, reducing the amount of raw materials and reduce costs.

2. High modulus

in order to maintain the static stiffness of the original wall thickness product, the thin-walled material is required to have a higher bending modulus. 

In particular, the new generation of PP vehicle materials need to bear a greater force during the use of the process, in the external force must maintain a good shape, so must have enough rigidity, generally need bending modulus of more than 1700 MPA, domestic products generally low modulus, less than 1700 MPA, high modulus can meet the needs of thin-walled.

3. High impact

automotive and household electrical appliances polypropylene materials must have good energy absorption and transfer ability, which requires the raw materials have appropriate impact strength and wide molecular weight distribution, under normal temperature (usually 23 ° c) , the notched impact of simply supported beam is required to be larger than 5KJ/m2. 

modulus 1700 corresponds to impact strength 9-10 kj/m2(23 ° C, notched simply supported beam) ;

modulus 1800 corresponds to impact strength 8-9 kj/m2(23 ° C, notched simply supported beam) ;

modulus 1900 corresponds to impact strength 6-7 kj/m2(23 ° C, notched simply supported beam) .

4. Low odor

modified polypropylene is mainly used in automotive interior. It is a kind of ultra-low-emission plastic particles developed to solve the problem of indoor air pollution. The material should have balanced mechanical properties, excellent processing properties, high heat resistance, low odor (polypropylene material odor ≤3) .

The low-odour polypropylene, which has solved the odour problem, will become the first choice of modified raw material for automobile modified plants. According to the standard PV3900.

5. the TVOC content is less than 50

Especially after the new National Standard“Air quality evaluation guidelines for passenger vehicles” was enforced on January 1,2017, solving the HCPP smell problem has become one of the key indicators for PETROCHEMICAL COMPANIES TO COMPETE; The main sources of the volatile components in low VOC polypropylene materials are as follows: (1) the solvents added in the synthesis process of polypropylene include Hexane, ethanol and Heptane; Second, in the synthesis of polypropylene catalyst and other small molecules will remain in the material, these low-molecular substances will make polypropylene materials have a certain amount of volatile organic compounds (VOC) . 

In the field of automotive interiors, the volatility of organic compounds in materials needs to be strictly controlled to ensure safety to the human body. When the toxic volatile gas used in automobile interior materials reaches a certain concentration, people will have headache, nausea, even convulsion and other symptoms in a short time, and will damage the liver, kidney, brain and nervous system, is a serious threat to human health. 

With the implementation of the new low VOC national standard“Guidelines for assessment of air quality in passenger vehicles” on 1 January 2017, the VOC problem of polypropylene has become a key indicator.