Polyethylene is commonly categorized into one of several major compounds, the most common of which include LDPE, LLDPE, HDPE, and Ultrahigh Molecular Weight Polypropylene. Other variants include Medium Density Polyethylene (MDPE), Ultra-low-molecular-weight polyethylene (ULMWPE or PE-WAX), High-molecular-weight polyethylene (HMWPE), High-density cross-linked polyethylene (HDXLPE), Cross-linked polyethylene (PEX or XLPE), Very-low-density polyethylene (VLDPE), and Chlorinated polyethylene (CPE). Low-Density Polyethylene (LDPE) is a very flexible material with unique flow properties that makes it particularly suitable for shopping bags and other plastic film applications. LDPE has high ductility but low tensile strength, which is evident in the real world by its propensity to stretch when strained. Linear Low-Density Polyethylene (LLDPE) is very similar to LDPE, but offers added advantages. Specifically, the properties of LLDPE can be altered by adjusting the formula constituents, and the overall production process for LLDPE is typically less energy-intensive than LDPE. High-Density Polyethylene (HDPE) is a robust, moderately stiff plastic with a highlypolyethylene-hdpe-trashcan-1 crystalline structure. It is frequently used in plastic for milk cartons, laundry detergent, garbage bins, and cutting boards. Ultrahigh Molecular Weight Polyethylene (UHMW) is an extremely dense version of polyethylene, with molecular weights typically an order of magnitude greater than HDPE. It can be spun into threads with tensile strengths many times greater than steel and is frequently incorporated into bulletproof vests and other high-performance equipment.

Biaxially oriented polypropylene (BOPP) film is a type of flexible packaging film. Biaxially oriented polypropylene overwrap film is stretched in machine and transverse directions. This results in a molecular chain orientation in both directions. This type of flexible packaging film is created via a tubular production process. A tube-shaped film bubble is inflated and heated to its softening point (this is different from the melting point) and is stretched with machinery. The film stretches between 300% - 400%. Alternatively, the film can also be stretched by a process known as tenter-frame film manufacturing. With this technique, the polymers are extruded onto a cooled cast roll (also known as a base sheet) and drawn along the machine direction. Tenter-frame film manufacturing uses several sets of rolls to create this film. The tenter-frame process generally stretches the film 4.5:1 in the machine direction and 8.0:1 in the transverse direction. That being said, the ratios are fully adjustable. The tenter-frame process is more common than the tubular variant. It produces a highly glossy, clear film. Biaxial orientation increases strength and results in superior stiffness, enhanced transparency, and high resistance to oil and grease. BOPP film also boasts increased barrier properties to vapor and oxygen. Impact resistance and flexcrack resistance are substantially better with BOPP versus polypropylene shrink film. Biaxially oriented polypropylene overwrap films are most commonly used for food packaging. They are fast replacing cellophane for applications including snack food and tobacco packaging. This is primarily due to their superior properties and lower cost. Many companies choose to use BOPP in place of traditional shrink films as they feature enhanced properties and capabilities that are superior to those of standard flexible packaging films. It should be noted that heat sealing is difficult for BOPP films. However, this can be made easier by coating the film after processing with a heat-sealable material or co-extruding with a co-polymer before processing. This will result in a multi-layer film.

According to customs data statistics: from January to February 2023, the domestic PE export volume is 112,400 tons, including 36,400 tons of HDPE, 56,900 tons of LDPE, and 19,100 tons of LLDPE. From January to February, the domestic PE export volume increased by 59,500 tons compared with the same period in 2022, an increase of 112.48%. 3361a1aab635d9eaba243cc2d7680a3 From the above chart, we can see that the export volume from January to February has increased significantly compared with the same period in 2022. In terms of months, the export volume in January 2023 increased by 16,600 tons compared with the same period last year, and the export volume in February increased by 40,900 tons compared with the same period last year; in terms of varieties, the export volume of LDPE (January-February) was 36,400 tons , a year-on-year increase of 64.71%; HDPE export volume (January-February) was 56,900 tons, a year-on-year increase of 124.02%; LLDPE export volume (January-February month) was 19,100 tons, a year-on-year increase of 253.70%. From January to February, polyethylene imports continued to decline, while exports continued to increase significantly. 1. Part of the equipment in Asia and the Middle East was overhauled, the supply of goods decreased, and the US dollar price went up, the domestic price was low, the price difference between internal and external markets was obviously inverted, and the import window was closed; Resumption of work, due to the impact of the previous epidemic control and other impacts, the resumption of work and production this year is relatively lagging behind, and the recovery of demand after the festival is weak. 3. In the first quarter, my country’s new PE production capacity was significantly launched, but the demand side did not follow up ideally. In addition, overseas device maintenance was still relatively concentrated in February, and the supply of external sources of goods decreased. The export operation of the industry was more active, and the export volume increased. It is expected to export in March Still growing slightly.

Polypropylene molecules contain methyl groups, which can be divided into isotactic polypropylene, atactic polypropylene and syndiotactic polypropylene according to the arrangement of methyl groups. When the methyl groups are arranged on the same side of the main chain, it is called isotactic polypropylene; if the methyl groups are randomly distributed on both sides of the main chain, it is called atactic polypropylene; when the methyl groups are arranged alternately on both sides of the main chain, it is called syndiotactic. polypropylene. In the general production of polypropylene resin, the content of isotactic structure (called isotacticity) is about 95%, and the rest is atactic or syndiotactic polypropylene. The polypropylene resin currently produced in China is classified according to the melt index and the additives added. Atactic polypropylene is a by-product of the production of isotactic polypropylene. Atactic polypropylene is produced in the production of isotactic polypropylene, and isotactic polypropylene is separated from atactic polypropylene by a separation method. Atactic polypropylene is a highly elastic thermoplastic material with good tensile strength. It can also be vulcanized like ethylene-propylene rubber.