Damping material is a special material with vibration and noise reduction and certain sealing properties, and polymer damping material is the most effective type of damping material, which is widely used due to its unique structure. Damping materials have been widely used for shock absorption and noise reduction of aircraft, rockets, various aircraft, armored vehicles, tanks, cars, and other transportation vehicles, as well as for wave absorption and stealth of submarines, and environmental protection. Polymer materials generally have significant damping near the glass transition temperature (Tg). When polymers are in a glass state, their modulus is very high, and molecules can hardly move, therefore they cannot absorb mechanical energy; In high elastic states, molecules move easily and cannot absorb sufficient mechanical energy; However, near Tg, the modulus of the polymer significantly decreases, accompanied by obvious mechanical damping characteristics. Mechanical vibration is converted into the motion of macromolecular chains or segments, and mechanical energy is converted into thermal energy through internal friction between molecules, achieving damping effect. The phase angle difference between strain and stress δ It is called the mechanical loss angle, commonly known as the tangent tan of the mechanical loss angle δ (also known as damping factor) to represent the magnitude of internal friction. The relationship between mechanical loss and damping performance is very close, and the greater the internal friction of the polymer, the better the damping effect δ The relationship between energy storage modulus E 'and loss modulus E' is as follows: Tan δ= E "/E ' Damping factor tan δ The larger the damping temperature range, the better the damping performance of the material.

During the injection molding process of plastic products, when it is found that plastic melt fills the cavity, if two or more strands of melt have cooled down in the front section when they meet, making it impossible for them to fully fuse, grooves will be formed at the intersection, forming fusion marks.

Polytetrafluoroethylene (PTFE) is a special type of engineering plastic that has good physical and chemical properties and can withstand "aqua regia", commonly known as the "king of plastics". PTFE has a wide temperature range and can be continuously used for a long time between 180-250 ℃. Its friction coefficient is very low, only 0.04, without water absorption and is not flammable. However, due to the non polarity of PTFE molecular chains, the mechanical properties of PTFE are poor. By utilizing the excellent friction and high-temperature performance of PTFE and using other engineering plastics with higher mechanical strength for blending modification, the advantages of each component can be comprehensively blended, achieving complementary advantages, and producing high-performance engineering plastic friction materials, thereby expanding the application field of engineering plastics.

Polyphenylene sulfide (PPS), also known as polyphenyl sulfide, is a thermoplastic resin with a benzene sulfide group in the main molecular chain. It is a special engineering plastic with excellent comprehensive performance and is widely used in fields such as electronics, electronics, machinery, aerospace, and chemical engineering.

The definition of plastic is a polymer compound formed from monomers through addition or condensation polymerization. Its resistance to deformation is moderate, intermediate between fibers and rubber, and mainly composed of resin, fillers, plasticizers, stabilizers, lubricants, pigments, and other additives. The main component of plastic is resin, which accounts for approximately 40% to 100% of the total weight of plastic. The basic properties of plastic are mainly determined by the nature of the resin, but additives also play an important role. Some plastics are basically composed of synthetic resins without or with little additives, such as organic glass, polystyrene, etc.

There are many low-quality plastic water cups on the market, and holding hot water can cause chemicals to dissolve into the water; The cup is also difficult to clean and can easily breed bacteria. In addition, polycarbonate plastic water cups, mainly made of bisphenol A, are also internationally recognized substances related to cancer risk.