What is Ultrasonic Welding when it comes to Plastic Parts? Title:
Body: One of the key reasons companies use injection molding for their parts is how precisely pieces can be manufactured — both in part complexity, and in aesthetics. Being able to establish how a part will look at the beginning of the design phase and retaining that vision through the manufacturing phase (barring any major necessary functional changes) is a level of control that injection molding provides where other processes fall short. Still, to be fully functional, some parts require finishing after they have been molded. This includes parts that need to be joined or attached to other components to form the fully realized part. But joining these pieces together usually requires screws, bolts, adhesives, or other hardware that ultimately defaces the finished piece and takes away from that aesthetically pleasing finish that designers work so diligently to perfect. Fortunately, there is another method of joining plastic parts that is less invasive, equally durable, ultimately much faster and easier for companies. Enter ultrasonic welding. What is Ultrasonic Welding? Ultrasonic welding is a process that joins two separate plastic pieces together to form one cohesive part. This is done using friction to generate heat, warming the plastics to a high enough temperature that they’re able to form a molecular bond. Specialized welding machines use a vibrating “horn” to apply high-frequency pressure via sound waves to the sides of the plastic pieces being welded together, which is what creates the friction and heat between the pieces to join them. Once the pieces are heated and joined, they need to cool for a set “hold time” to complete the bonding process. As the melded plastic cools, pressure is maintained — this is what completes the “weld” between the pieces, and forms the finished molecular bond. Why Use Ultrasonic Welding for Plastic Parts vs Traditional Assembly Methods? Ultrasonic welding forms a clean, strong bond between plastic pieces. Because it only forms a bond using heat and pressure, with no outside additional materials or agents, the welded part is left uncontaminated from outside agents, preventing the introduction of undue duress, corrosion, or discoloration into the part. This is also ideal for joining different types of plastics that may not be able to be molded together, or for parts that needed to be molded in separate batches. This does not work for joining all material types, but those that are chemically compatible and have similar melt flow dynamics tend to weld together easily. The ultrasonic welding process is also fully contained, meaning no additional assembly is required once the assembly process is finished. Because this process takes seconds to minutes per piece, rather than minutes to hours for physical assemblies, it ultimately saves time and money during the manufacturing process, as well. Considerations with Ultasonic Welding