Ultrasonic welding and plastic properties 1. Summary Ultrasonic welding is a high-tech technology for welding thermoplastic plastic products. All kinds of thermoplastic rubber parts can be welded using ultrasonic welding without adding solvents, adhesives or other Auxiliary products. Its advantages are to increase productivity multiple times, reduce costs, improve product quality and production safety. ? The principle of ultrasonic plastic welding is that the generator generates 20KHZ (or 15KHZ) high-voltage and high-frequency signals. Through the energy conversion system, the signal is converted into high-frequency mechanical vibration, which is added to the plastic product workpiece and passes through the surface of the workpiece and the inner molecules. The friction causes the temperature transmitted to the interface to increase. When the temperature reaches the melting point of the workpiece itself, the workpiece interface melts rapidly, and then fills the gaps between the interfaces. When the vibration stops, the workpiece is cooled and shaped under a certain pressure at the same time. Achieve perfect welding effect. 2. Materials and ultrasonic welding characteristics
ABS? Acrylonitrile butadiene? Phytoethylene polymer is light in weight, has both flexibility, rigidity and chemical resistance, and has a wide range of uses. This material has good thermal conductivity and is particularly suitable for ultrasonic welding.
General purpose polystyrene, with light specific gravity, strong corrosion resistance to water and chemicals, stability and good insulation, especially suitable for injection and extrusion molding, commonly used Used in the manufacturing of toys, decorations, toilet equipment, pans, lenses, floating wheels, etc. Due to its high elasticity coefficient, it is suitable for ultrasonic welding. ?Acrylics? Acrylic has high hardness, is resistant to heavy impact, and is not affected by acids. It has high optical clarity and good colorability. It is often used in automobile taillights, dashboards, medals, faucet handles, etc. When used for ultrasonic welding, attention must be paid to the issue of brightness fading.
Impact?ps? Acetal acetal, high tensile and compressive strength, good wear resistance, the strongest and most powerful, commonly used for picks and screws , bearings, rollers, kitchen utensils, etc., due to the low friction coefficient, high vibration amplitude and long welding time are required when using ultrasonic welding.
20-30?glass?Filled?PS?Glass-woven reinforced polystyrene Celluloeics?ester acid woven fibrous material? The material is easy to change and discolor when ultrasonic vibration occurs, and the contact surface is not easy to absorb energy. Welding More difficult.
Unmodified PP polypropylene has light specific gravity, good insulation, high strength, and can withstand heat and chemical corrosion. It can be made into ropes and other fabrics after spinning. The manufactured products include toys, luggage, music casings, electrical insulators, food packaging, etc. ?This material has a low elastic coefficient and is easy to attenuate sound wave vibration, making it difficult to weld. ?Noryl polyphenylene ether has extremely strong properties, good electrical properties, and high insulation. It is commonly used in electronic parts. Due to the high melting point, the required welding time is long and the amplitude is high.
Filled?pp?Reinforced polypropylene; Nylon,
Nylon?, strong material, wear-resistant, extremely low friction coefficient?, acid-resistant, commonly used as bearings, gears, pipes ?, kitchen utensils, brushes, etc. When ultrasonic welding is used, the welding time is long due to the high melting point. Drying before welding will make welding easier.
PVC
Polyvinyl chloride has electrical properties, is resistant to weak chemicals, has excellent low-temperature properties, and is flame retardant. It is often used in various synthetic leather hoses and materials. Membrane, etc., are made of soft material and are easy to attenuate sound wave vibration, and the welded surface is easy to deteriorate. ?P.C. Polycarbonate?, heat-resistant, has excellent transparency, high tensile and bending strength, and is often used in lenses, such as heat pipes, filters, etc. Because the welding point is high, the welding time required is long. Since the material is hygroscopic, it should be dried before welding. Polyster: Polyester welding has high energy, High Density, PE, high density polyethylene, small specific gravity, high flexibility at low temperature and room temperature, waterproof, anti-corrosion, and can be made into various colors. ? Low-priced products, often used in pans, packaging films, soft water pipes, baby bottles, soft ropes, etc. The higher the density, the more suitable it is for ultrasonic welding.
Polysulfone
Polysulfone is hard, strong, capricious, and does not affect its electrical properties when exposed to heat for a long time. It is commonly used as TV parts protectors, motor parts, etc. . Because the welding point is high, higher energy is required for welding. ?Low?Density?PE? Low density polyethylene
Polypheny?lene?Qxide (ppO) Polyoxyxylene, heat-resistant and moisture-resistant, chemical-resistant, not afraid of steam, commonly used as terminals, Rotors, casings, impellers and pipe fittings have high melting points and require high energy for welding.