Mr. Ma, a citizen, parked his car near his residential community the day before yesterday. Unexpectedly, the car was hit by bricks that fell from a building during renovation. The damage to his car was over ten thousand yuan, but the insurance company only compensated 70%. On the wall beside the car, there was a notice saying "No parking under construction upstairs." After negotiation, the construction party finally agreed to bear 20% of the maintenance cost. The construction party stated that they would restore the warning tape as soon as possible to prevent similar incidents from happening again.　

According to relevant reports, some citizens have raised the question of whether the white LED lights on the isolation belt of Jianghai Avenue overpass have a certain impact on driving and whether they can be changed in color to facilitate driving. In response, the relevant department provided an explanation: Based on a comprehensive comparison and screening of related experiments, white LED lights are more suitable for road lighting.　

Polyoxymethylene is a high-density, highly crystalline linear polymer compound without side chains. It has a highly crystalline structure in the solid state. The crystallinity of copolymer formaldehyde mixed with C-C bonds on C-O bonds is 70% to 75%. Due to the shorter distance between C-O bonds and C-C bonds, the filling density along the chain axis is greater, which makes the crystallinity of homopolymethylene in the main chain with C-O bond positions higher, reaching 75% to 85%.　

To produce homopolymer formaldehyde with formaldehyde as the monomer, high-purity formaldehyde monomers must be used. The production process mainly consists of three steps: purification of formaldehyde, polymerization and end sealing.　

PC/PE alloys are manufactured by mechanical blending. The dried PC and PE are added to a mixer equipped with an insulation device to mix evenly. Then they are transferred into the extruder hopper. The temperature of the extruder barrel is controlled at around 290℃. After melt extrusion, cooling and pelletizing, the product is obtained.　

There are two common production methods: 1. Long fiber method 2. Short fiber method