The Difference Between PP Material And PE Material In Rotational Molding Process
There are significant differences between rotomolded PP materials and PE materials in many aspects. These differences are mainly reflected in composition, physical properties, chemical properties, processing characteristics and application fields. The following is a detailed analysis of the differences between the two:
1. Ingredients
PP material (polypropylene): It is made of propylene monomer through polymerization reaction and has a three-dimensional molecular chain. PP materials can be divided into homopolymerized PP and copolymerized PP according to their different polymerization methods. Copolymerized PP is divided into block copolymerization and random copolymerization.
PE material (polyethylene): It is polymerized from ethylene monomer and has a relatively simple molecular chain structure. There are many types of PE materials, such as LDPE (low density polyethylene), HDPE (high density polyethylene) and LLDPE (linear low density polyethylene). Different types of PE also have different physical properties.
2. Physical properties
PP material: has high strength, hardness and rigidity, but relatively low toughness. PP material has a low density, is one of the lightest varieties of all plastics, and has good insulation properties. However, PP materials have poor cold resistance and low low-temperature impact strength, making them unsuitable for use in low-temperature freezing environments.
PE material: usually soft and transparent, with good flexibility and low temperature resistance. The density of PE material is slightly higher than that of PP material, but it is still a lightweight material overall. Different types of PE also differ in flexibility, transparency, etc.
3. Chemical properties
PP material: has good chemical stability and can resist the erosion of most chemicals, but has poor oxidation resistance. Under high temperature and ultraviolet radiation, PP materials are prone to oxidative degradation.
PE material: It also has good chemical stability and can resist the erosion of various chemical substances. However, PE materials also have relatively poor UV resistance and oxidation resistance, and long-term exposure to sunlight may cause performance degradation.
4. Processing characteristics
PP material: Due to its higher melting point and crystallinity, PP material requires higher processing temperatures and requires better processing equipment and technology. At the same time, the fluidity of PP materials is relatively poor, so attention needs to be paid to controlling temperature and pressure during processing.
PE material: relatively easy to process and suitable for a variety of plastic processing methods, such as blow molding, injection molding, etc. PE material has a wide processing window and is suitable for long-term high-temperature environments. It also reduces the requirements for rotational molding machinery.
5. Application areas
PP material: widely used in the manufacturing of household appliances, packaging materials, auto parts, fiber production and other fields. Due to its high strength and heat resistance, PP materials are particularly suitable for use in environments that need to withstand higher temperatures and pressures.
PE material: often used to make plastic bags, containers, pipes, mulch films, etc. PE material has good flexibility and low temperature resistance, making it widely used in packaging and agricultural fields. At the same time, PE materials are also widely used in the medical and food packaging fields and are popular for their non-toxic, tasteless and odorless properties.
To sum up, there are significant differences between rotomolded PP materials and PE materials in terms of composition, physical properties, chemical properties, processing characteristics and application fields. When choosing which material to use, specific application needs and conditions need to be considered.