Common sense of ultrasonic welding machine

Common sense of ultrasonic welding machine In general, plastic ultrasonic processing of low melting point is superior to the plastic of low hardness and high melting point. Therefore, this is involved in the distance of ultrasonic processing distance, as far as section 7, close range welding. The effect of plastic parts on ultrasonic welding The different processing forms of plastic parts, such as injection molding, extrusion, and blow molding, and different processing conditions can cause certain influences on ultrasonic welding. A: humidity defects: humidity defects in production have stripes or loose in the process of plastic parts, humidity defects in welding attenuation useful energy, make the seal water seepage, lengthen the period of welding, so the plastic parts before welding high humidity drying process. Formaldehyde and so on. B: the impact of the injection molding process: The adjustment of injection molding process parameters will cause the following defects: Change in size (contraction, bending) Weight variation Surface damage The unity is not good C: the shelf life: after plastic injection molding, after the minimum of 24 hours, the welding is done to eliminate the stress and deformation of the plastic parts. Shapeless plastic is not required by injection molding plastic. D: recycled plastic The strength of recycled plastic is poor, and the adaptability of ultrasonic welding is also poor, so it is necessary to consider all kinds of design dimensions, such as using recycled plastic. E: molds and impurities The stripper and impurities have a certain effect on ultrasonic welding. Although ultrasonic processing may be able to remove the solvent, impurities and so on the surface of the processing surface, but for the requirement to seal, or in the case of high intensity, should be removed as far as possible. In some cases, it is necessary to clean the plastic first. Plastic design Modern injection molding can provide perfect welding plastic parts. When we decide to use ultrasonic welding technology to complete the fusion, the structural design of the plastic parts must first be considered as follows: The size of the weld (i.e. the intensity required) Do you need water tight and gas tight Do you need a perfect look Avoid the overflow of plastic melt or synthetic Whether the head is suitable for the processing requirement The quality of welding can be obtained through the following control: material The structure of plastic parts The position and design of the welding line The size of the welding surface The position and looseness of the upper and lower surfaces The contact surface of the welding head and plastic parts The smooth welding path The support of the bottom module In order to achieve the perfect and repeatable fusion welding, three main design directions must be followed: (1) the initial contact with the surface of the two must be small, so that the energy you need to focus on, and try to reduce the total energy needed to weld (time) to complete. To find suitable methods for fixing and aligning, such as; Plastic parts for sockets, steps, etc. The welding surfaces around the interface must be uniform and close to each other. If possible, contact surfaces as far as possible in the same plane, allowing the energy conversion to be consistent. The working principle of ultrasonic plastic welding machine Ultrasonic plastic welding machine for welding principle is: the machine will power through ultrasonic transducer into ultrasound can beyond the human ear hearing threshold (that is, the frequency of high frequency mechanical vibration can), the energy through the welding head conduction to the plastic workpiece, tens of thousands of times per second the amplitude of ultrasonic frequency and must make plastic joint surface of the workpiece after violent friction melting. The temporary pressure on the workpiece after the vibration stops and the two welded pieces solidified in a molecular link. Normal welding time is less than one second, and the intensity of welding is comparable to that of the body. The application of ultrasonic in plastics processing: The ultrasonic wave used in plastic processing, the current number of work frequencies is 15KHZ, 18KHZ, 20KHZ, 40KHZ.The principle of which is the compressional wave crest amplitude to the plastic parts of the gap, in the case of pressure, the two plastic parts or other parts in contact with the plastic parts of molecular collisions produce melting, make contact with a plastic fusion, the purpose of processing. The composition and principle of ultrasonic welders The ultrasonic welding machine mainly consists of several parts: the generator, the pneumatic part, the program control part, the transducer part. The main purpose of the generator is to convert the power supply of 50HZ to high voltage waves that are converted to high frequencies (such as 20KHZ). The main function of pneumatic part is to complete the pressure of pressure and pressure in the process of processing. Control parts of the machine to control the process of the whole machine. The transducer is part of the conversion of the high voltage wave generated by the generator to mechanical vibrations, passing through, amplifying and reaching the surface of the processing. Parameter and regulation of ultrasonic welding machine: The general ultrasonic welding machine has the following parameters that can be adjusted: A: the tuning knob on the ultrasonic generator: this is the key adjustment knob for the ultrasonic welder. The purpose of the adjustment is to make the frequency of the high piezoelectric signal emitted by the ultrasonic generator consistent with the mechanical resonance frequency of the transducer part. The method is the light touch test switch, the control of the knob on the left and right, the current of the load indicating is minimal, and the tuning step is complete. B: the amplitude gear: this knob has no knobs on the machine. Its function is to achieve the high speed output amplitude by adjusting the output voltage of the generator. C: pneumatic part: includes governor, pressure adjustment knob. The governor is used to adjust the upper and lower velocity of the cylinder. The pressure adjustment knob regulates the working pressure. D: welding TIME (WELD TIME) : used to adjust the TIME of ultrasonic emission, under general plastic welding TIME is 0.6 S, often more than 1.5 S can be seen as failure welding welding TIME (can be seen as the amplitude is not enough, or design unreasonable). E: the holding TIME (HOLD TIME) : the holding TIME is equal to the processing of plastic parts after curing TIME, usually if the plastic parts the fixed position of set well, this TIME can need not consider, if there is a spring inside the plastic parts, such as the long TIME should be accordingly adjusted. F: trigger adjustment: there are two ways to trigger adjustment, one is delayed triggering. This adjustment is generally indicated as DELAY TIME. It refers to the time when the machine begins to emit ultrasonic waves. By adjusting, the ultrasonic can be fired first, then the plastic parts will be pressed before the ultrasonic wave can be triggered. Another is pressure triggering. This type of trigger is found in the American BRANSON 8400 and 8700 form of ultrasonic welders, which are designed to regulate the pressure of plastic parts to trigger ultrasound. For larger plastic parts, the use of the first trigger ultrasonic refusion, or a smaller trigger, to prevent the vibration failure. The effect of plastic material on ultrasonic welding Ultrasonic wave propagation in the plastic parts, plastic parts more or less have the absorption and attenuation of ultrasonic energy, to a certain influence on effect of ultrasonic machining, plastic generally has the branch of amorphous materials, according to the hardness of hard plastic and soft plastic, and modulus of distinction, generally speaking, high hardness, low melting point plastic ultrasonic machining performance is better than that of low hardness, high melting point of the plastics. Therefore, this is involved in the distance of ultrasonic processing distance, as far as section 7, close range welding. The effect of plastic parts on ultrasonic welding The different processing forms of plastic parts, such as injection molding, extrusion, and blow molding, and different processing conditions can cause certain influences on ultrasonic welding. A: humidity defects: humidity defects in production have stripes or loose in the process of plastic parts, humidity defects in welding attenuation useful energy, make the seal water seepage, lengthen the period of welding, so the plastic parts before welding high humidity drying process. Formaldehyde and so on. B: the impact of the injection molding process:The adjustment of injection molding process parameters will cause the following defects: Change in size (contraction, bending) Weight variation Surface damage The unity is not good C: the shelf life: after plastic injection molding, after the minimum of 24 hours, the welding is done to eliminate the stress and deformation of the plastic parts. Shapeless plastic is not required by injection molding plastic. D: recycled plastic The strength of recycled plastic is poor, and the adaptability of ultrasonic welding is also poor, so it is necessary to consider all kinds of design dimensions, such as using recycled plastic. E: molds and impurities The stripper and impurities have a certain effect on ultrasonic welding. Although ultrasonic processing may be able to remove the solvent, impurities and so on the surface of the processing surface, but for the requirement to seal, or in the case of high intensity, should be removed as far as possible. In some cases, it is necessary to clean the plastic first. Plastic design Modern injection molding can provide perfect welding plastic parts. When we decide to use ultrasonic welding technology to complete the fusion, the structural design of the plastic parts must first be considered as follows: The size of the weld (i.e. the intensity required) Do you need water tight and gas tight Do you need a perfect look Avoid the overflow of plastic melt or synthetic Whether the head is suitable for the processing requirement The quality of welding can be obtained through the following control: material The structure of plastic parts The position and design of the welding line The size of the welding surface The position and looseness of the upper and lower surfaces The contact surface of the welding head and plastic parts The smooth welding path The support of the bottom module In order to achieve the perfect and repeatable fusion welding, three main design directions must be followed: (1) the initial contact with the surface of the two must be small, so that the energy you need to focus on, and try to reduce the total energy needed to weld (time) to complete. To find suitable methods for fixing and aligning, such as; Plastic parts for sockets, steps, etc. The welding surfaces around the interface must be uniform and close to each other. If possible, contact surfaces as far as possible in the same plane, allowing the energy conversion to be consistent.