Troubleshooting method of ultrasonic plastic welder thermoplastic sound wave welding machine

Troubleshooting method of ultrasonic plastic welder thermoplastic sound wave welding machine

Ultrasonic plastic welder is prominent selection to joint thermoplastic in creating a solid weld, during this process,high frequency ultrasonic vibrations are applied to localized area where work-pieces are joined together under controlled pressure, the vibrations cause the plastic to form a solid weld without use of high temperature, glue or fasteners

Because this method uses acoustics rather that heat or fastening materials, it offers many advantages, such as reliability, repeatability, low energy consumption and efficiency on materials and labor. However, ultrasonic plastic welder offers many salient features, it is an extremely delicate process that can result in various problems, fortunately, most malfunction with ultrasonic plastic welder is traceable

Despite being a sophisticated process, ultrasonic plastic welder is relatively simple to troubleshoot, to assist you in determining how to fix your ultrasonic plastic welder malfunctions

01: Over-weld

Over-weld is when the resulting weld is more extensive that is specified, over-weld can result in functional and aesthetic problems, altering the dimensions, finish and functionality of the part

Malfunction: Over-welding often occurs because of excess energy that leeches outside of the intended area, affecting surface that are not  intended to be welded, the following are the common causes of over-welding

011: Too much energy is being exert into the joints

012: The weld is being applied for too long, resulting in excess energy

013: The weld travels distance, also know as the melting down, distance or collapse, is too high

014: The absolute is too high

Resolving Method: The best method to reduce over-welding is to reduce the amount of energy applied to the part, this can be done through the following channels

015: Reduce the pressure, trigger force and down speed used to reduce overall energy input

016: Lessen the overall amount of time exert into the weld

017: Decrease the amplitude produced by the ultrasonic plastic welder by changing to a lower ratio booster, digitally reducing the amplitude percentage, using amplitude profiling or using a lower gain horn

018: Reducing the absolute distance by re-calibrating the absolute distance and adjusting it accordingly

When correcting an over-welding, it is important to adjust each parameter individually rather than adjust them all simultaneously, you may also consider making sizeable parameter changes of 20 to 30 percent to induce opposite failure, this way, you can more easily gauge the efficacy of the charge and work to find the optimal setting

02: Under-welding

An under-welding is the opposite of an over-welding, in these cases, the weld has not covered the entire area needed, so some areas are left untouched, this causes serious functional problem, as the part is not welded together strongly sufficient to meet specification

Malfunction:Under-welding most often happen for the opposite cause as over-welding, alternate of too much energy being put into the part, too little energy is being put in. Additionally, under-welding may be improper setup. The followings are the most common causes of under-welding

021: Insufficient energy is being applied to the working-piece

022: The amount of time the weld is applied is too short

023: The amplitude of the ultrasonic welder is too low

024: The absolute distance is too low

025: Energy is being lost into the fixture rather than focusing on the part

026: The part is contaminated with mold release or moisture

027: The part is set incorrectly on the anvil

Resolving method: under-welding is easily fixed with small adjustments in procedure and welder settings, this can be accomplished through the following steps

028: Check all parts before welding to ensure that they are clean and free of moisture

Re-calibrate the base of welder to ensure that it is level and makes full contact with the attachment before welding

029: If energy is being lost into the fixture, change the fixture to a rigid material like aluminum

0210: Increase the pressure, trigger force or down speed to increase the energy applied

0211: Increase the amount of time the weld is applied

0212: Increase amplitude by using a higher ratio booster or changing to a higher gain horn

0213: Increase the absolute distance

With under-welding, it is generally best to check the setup and cleanliness of the parts before adjusting welder setting, as these problems are quickly and easily remedies, once these aspects have been eliminated as possible causes, adjust welder setting one at a time to achieve desired results

03: Non-uniform joint weld

Non-uniform welds are both aesthetically unappealing and can have functional drawbacks, non-uniform welds are mot as strong in some area as in others, meaning that the part my have a low-quality seal

Malfunction: Faulty parts or fixtures most often cause non-uniform welds around the joint, most often, these issues are caused by the following errors

031: One part is improperly make or warped,or the wall is flexed so that is doesn’t fit properly to the other part

032: The part is improperly cleaned, leaving behind mold release or moisture that can reduce the efficacy of the weld

033: The parts are not properly aligned during setup

034: Filler is accumulating in certain area, resulting in more joint weld in some areas over others

035: The horn, fixture and part are not parallel or have poor contact, resulting in a low-quality weld

036: The fixture on which the part rests is not sufficiently supported

037: The horn of the ultrasonic welder is not producing an uniform amplitude

Resolving Method: Non-uniform joint welds are mot often fixed with simple part, equipment and setup testing and adjustment, common solutions include

038: Check the part for any signs of manufacturing error or warping, this may include checking the parts’ dimensions and molding conditions for any inconsistencies, if the part is not made to specification, tighten tolerances and check molding conditions to ensure that parts are made correctly, if wall flexure is occurring, consider increasing wall thickness, and internal ribs or modifying the fixture to prevent it

039: Check the parts for any signs of mold release or moisture, if there is any evidence of improperly cleaned parts, update cleaning protocols appropriately

0310: Check the setup to ensure that parts are properly aligned before and during welding, keep an eye out from proper alignment of mating parts and any shifting during the welding process

0311: Check the parts for signs that filler is accumulating in one area over another, if this is an issue, make sure that you are using short fibers and reduce the amount of filler used

0312: Check the setup to make sure that the fixture is firm and that the horn is making uniform, contact with the part, if the setup is not right, shim the fixture as needed and test the parallelism

0313: If the fixture is sufficiently supported, you may want to either improve support or, in especially bad cases, change to a rigid fixture

0314: If the problem may be the horn, have the horn tested and modified or repaired to produce an uniform amplitude

There are many more potential causes of non-uniform joint welds that most other ultrasonic welding issues, so be sure to be systematic in the troubleshooting procedures if this issue arises

04: Part-to-part welds inconsistent

In Some cases, the weld on one part may differ from the weld on another, this poses a problem for a company’s overall production, value, as production consistent is a point of interest for many clients

Malfunction: There are numerous potential causes of part-to-part inconsistencies, many of them relate to part, setup and procedure issue, including the following

041: The parts are improperly or inconsistently cleaned, leaving behind mold release or moisture that can negatively effect weld consistency

042: The ultrasonic plastic welder is producing less consistent results due to maintenance issue or a drop in air line pressure

043: The parts are made with poor-quality or compatible materials, resulting in less consistent results

044: Too much filler is being used or is distribute unevenly

045: The parts are made inconsistently so that dimensions do not match from part to part

046: The parts are designed in a way that they fit poorly

Resolving method: Many issues that lead to inconsistent weld results are fixable with basic changes at the process level, but higher-level issues may require more extensive fixes, here are some potential solutions to help with part-to-part consistency

047: Check the cleaning procedures to make sure that all parts are cleaned consistently to eliminate mold release and moisture

048: Check the welder to ensure that it is functioning properly, if a drop in air-line pressure is the cause of the problem, check that your supply line capacity and compressor output supports the number of operating welders, if this isn’t the cause of the problem, have a professional check you welder to ensure that it is operating properly

049: Check your materials to ensure that they are good quality and compatible, poor-quality materials may have too much regrind in them, you can check for material compatibility by referring to your supplier specifications

0410: Check the amount and distribution of your filler, you may need to check molding condition to ensure that filler is mixed thoroughly and not accumulating near weld area, if possible,try to reduce the percentage of filler used and change the type of filler

0411: To check that parts are made consistently, check the dimensions of several parts, if inconsistencies are found, you may need to tighten tolerances and check molding conditions to ensure that parts are made more consistently

0412: In some cases, the design of the part may not facilitate consistent results due to poor part fits or incorrect joint design, in these cases the design of the part may need to be adjusted

Part-to-part weld inconsistencies can be caused by issues at any level of part design, so it is important to troubleshooting from the least complex to the most complex possible causes

05: Marking

Marking is when the weld process causes a problem in the surface finish of a part, while marking doesn’t always affect the dimension or functionality of a part, marking can negatively affect the aesthetic results

Malfunction: Marking is often caused by the same problem as over-welding and non-uniform joint welds, most often, marking results from setup and process errors some part fit issue can also result in marking

051: The horn, fixture and part are not aligned properly, resulting in uneven contact

052: The energy director is too large, resulting in the dispersal of energy beyond the weld area

053: The horn of the ultrasonic plastic welder heats up to much

054: The part doesn’t fit properly into the fixture, causing the welder to hit area that it is not meant to

055: The part is designed with localized high spot along the surface, such as details or raised lettering

Resolving Method: Most marking issues can be resolved by adjusting the setup or process, though some errors may require a slight part redesign if the issue persists

056: Check the alignment of the horn, fixture and part, this may require making adjustments to bring everything level

057: Reduce the size of energy director to improve localization

058: Troubleshoot the horn of the ultrasonic plastic welder to determine if it is heating up to much, some issue may require repair or setting adjustments

059: Check the part to make sure that it sits properly in the fixture, if it doesn’t check the dimensions of part and the fixture, resolving this issue may require increasing part tolerances

0510: IF the part is designed with high spots that pose a consistent issue, consider redesigning the part to have recesses instead

If the above solutions do not resolve the marking issue, use the solutions provided for over-welding, as marking is a common side-effect of over-welding

06: Flash

Flash is thin amount of excess plastic that appears on the joining point after welding,flash can negatively affect the surface quality of the part, potentially affecting both the functional and aesthetic quality of the finished piece

Malfunction: Flash is often caused by excess energy application and poor part design, some of the most significant causes are listed below

061: The weld is applied for too long

062: The energy director is too large

063: The joint is poorly designed or inconsistent

Resolving Method: Flash is often fixed with slight adjustments in process, though consistent issues with flash many require slight part redesigns

064: Reduce the weld time

065: Reduce the size of energy director or reduce the applied pressure

066: Redesign the joint to direct flash appropriately and increase tolerances to minimize variation

07: Misalignment

Misalignment of the assembly after welding is a significant problem as the faulty product will likely need to be scrapped

Malfunction: Misalignment is mot often caused by issues with part design and setup, though over-welding may also be cause of error

071: The matching parts are not aligned correctly before welding

072: The fixture is not supported properly, resulting in movement during welding

073: The parts are inconsistent or prone to warping

Resolving method:Misalignment most often requires adjustments to the part or fixture, these potential fixes are listed below

074: Add alignment features like pines and sockets to the mating halves to help improve alignment

075: Redesign the fixture with better support and alignment to minimize movement

076: If the part is prone to well flexure, redesign the part with ribs or thicker walls, if the parts are inconsistent, tighten tolerances and check the molding pressure to ensure that parts produced need specifications

If the above issues and solutions do not resolve the problem, troubleshoot for over-welding, another common cause of misalignment

08: Internal components damaged or welded

If a part includes internal components, there must remain untouched during the welding process, unfortunately, damage to internal components is a frequent issue

Malfunction: Internal component damage is often caused by procedural or design errors such as the following

081: Too much energy is applied

082: The weld is applied for too long

083: The internal component is mounted improperly

Resolving method: Internal component damage can be rectified by making small changes to procedure, though some issue may require redesigns

084: Reduce the energy applied by reducing amplitude, pressure or down speed

085: Reduce the amount of time the weld is applied

086: Redesign the part to ensure that internal components are mounted properly and isolated from the housing and any ares that require welding

In some cases, you may have trouble because internal parts are physically welded along with their housing in this cases, the problem is usually that the internal parts are made of the same material as the housing, the easiest solution to this issue to change the material of the internal parts so that it is incompatible with the housing material, or vise versa

09: Melting or fracture of parts

Excess melting and fracture can result in part becoming unusable, leading to excess waste and longer lead times

Malfunction: Melting and fracture are most often caused by issues in welding procedure and part design, including the following

091: Too much energy in applied to the part

092: The part is molded incorrectly, resulting in internal stress, flow lines and other problems

093: The part features sharp internal corners

Resolving Method: Melting and fracture can be resolved with small, relatively simple fixes like the following

094: Reduce the weld time, amplitude or pressure to reduce applied energy

095: Check the molding conditions, and process parameters to ensure that parts are molded correctly

096: Redesign the part with rounded corners instead of sharp corners

10: Diaphragmming

Diaphragmming, also know as the “oil-canning” effect, occurs when a wall distorts outward to create a bubble, this issue negatively affect the aesthetic and functional valve of the part, often resulting in scrapping the affected part

Malfunction: Diaphgragmming is often caused by issues in the welding process, though certain, design, choices exacerbate these issue

101: The welder is applied too much energy to the pat

102: The horn used is wrong or is placed in the wrong area

103: The part features a gate or thin wall

Resolving Method:Diaphgragmming can be avoided by changing the welding process or redesigning features of the part specifically to avoid this issue

104: Reduce the weld time or amplitude used

105: Eliminate horn contact over the area of concern or change the horn type to one which a nodal plunger or a vent hole, also, check that the horn fits the part appropriately

106: Redesign the part to change the shape of the gate or increase of the walls

The ultrasonic plastic welder process can run into many problems, most of which can be resolved with some basic troubleshooting techniques, there may be situation where the problem is your ultrasonic plastic welder, in these case, need a selective guidance from manufacturer, keepleader can fabricate your individual production in avoiding possibility of relative malfunctions not only with our knowledgeable concentration but also with our practical experience