1, density
PP is the smallest of all synthetic resins, only 0.90~0.91g/cm3, which is about 60% of PVC density. This means that a larger number of products of the same volume can be produced with the same weight of raw materials.
2, mechanical properties
The tensile strength and rigidity of PP are relatively good, but the impact strength is poor, especially at low temperatures. In addition, if there is orientation or stress during molding of the article, the impact strength is also significantly reduced. Although the impact strength is poor, its mechanical properties can compete with higher cost engineering plastics in many fields after modification by filling or reinforcement.
3, surface hardness
The surface hardness of PP is low in five general-purpose plastics, only better than PE. When the crystallinity is higher, the hardness is also increased correspondingly, but still not as good as PVC, PS, ABS, and the like.
4, thermal properties
Among the five general-purpose plastics, the heat resistance of PP is the best. PP plastic products can work at 100 ° C for a long time, and when there is no external force, the PP products will not be deformed when heated to 150 ° C. After the use of a nucleating agent to improve the crystalline state of PP, the heat resistance can be further improved, and it can even be used to make a vessel for heating food in a microwave oven.
5, stress crack resistance
Stress is left in the molded product, or the product works under continuous stress for a long time, which may cause stress cracking. Organic solvents and surfactants can significantly promote stress cracking. Therefore, the stress cracking test is carried out in the presence of a surfactant. A commonly used auxiliary is an alkyl aryl polyethylene glycol. Tests have shown that PP has good resistance to stress cracking when immersed in surfactant, and has good resistance in air, and the smaller the melt flow rate of PP (the larger the molecular weight), the stronger the stress crack resistance.
Please feel free to contact us if you have any problems.
Xiamen LFT Composite Plastic Co.,Ltd
Candy Hu
Email: candyhu@lfrtplastic.com
Tel : 0086-186-5906-9962 (wechat/whatsapp)
Skype:candy328520
Address : No. 27,Hongxi Road, Ma xiang town, Xiang 'an district, Xiamen(361000),China
