你的超聲波焊接質量怎麼了？——塑料焊接技術
你的超聲波焊接質量怎麼了？——塑料焊接技術
What Happened to Your Ultrasonic Weld Quality?
你的超聲波焊接質量怎麼了？
The most important factor in troubleshooting problems in ultrasonic welding is understanding the fundamentals of the process.
超聲波焊接中故障排除中，重要的因素是了解超聲波焊接過程的基本原理。
Sometimes poor ultrasonic welds can be traced back to the injection molding process. Injection mold wear can lead to a rounded energy director in the part (upper right), which produces a weak weld (lower right). A well-maintained mold produces a sharply pointed energy director (upper left), which produces a stronger weld (lower left) with lower welding amplitude and less flash.
有時不良的超聲波焊縫可以追溯到注射成型過程。注塑模具磨損會導致零件(右上)出現圓形能量指向，從而產生弱焊縫(右下角)。維護良好的模具產生尖銳的能量指示符(左上)，產生更強的焊縫(左下角)和較低的焊接幅度和較少的溢料。
The most important factor in troubleshooting problems in ultrasonic welding is understanding the fundamentals of the process. With this basic knowledge, most problems can be easily diagnosed and resolved. Even so, sometimes your time-tested weld recipe may suddenly fail for no discernible reason.
超(chao)聲(sheng)波(bo)焊(han)接(jie)中(zhong)故(gu)障(zhang)排(pai)除(chu)中(zhong)重(zhong)要(yao)的(de)因(yin)素(su)是(shi)了(le)解(jie)超(chao)聲(sheng)波(bo)焊(han)接(jie)過(guo)程(cheng)的(de)基(ji)本(ben)原(yuan)理(li)。有(you)了(le)這(zhe)些(xie)基(ji)本(ben)知(zhi)識(shi)，大(da)多(duo)數(shu)問(wen)題(ti)都(dou)可(ke)以(yi)很(hen)容(rong)易(yi)地(di)診(zhen)斷(duan)和(he)解(jie)決(jue)。即(ji)使(shi)如(ru)此(ci)，有(you)時(shi)你(ni)經(jing)過(guo)時(shi)間(jian)考(kao)驗(yan)的(de)焊(han)接(jie)配(pei)方(fang)可(ke)能(neng)會(hui)突(tu)然(ran)失(shi)效(xiao)，沒(mei)有(you)明(ming)顯(xian)的(de)原(yuan)因(yin)。
Perhaps your welder has been running the same application for months, maybe years, with no problems. Abruptly, this cheery continuity is disrupted. Has your weld strength decreased? Are you seeing excessive flash? Does your welder overload as soon as the cycle starts? Here, we will discuss a few unseen factors that can cause sudden changes in your weld quality and how to prevent and correct them.
也(ye)許(xu)您(nin)的(de)焊(han)工(gong)已(yi)經(jing)運(yun)行(xing)了(le)幾(ji)個(ge)月(yue)，也(ye)許(xu)幾(ji)年(nian)，沒(mei)有(you)問(wen)題(ti)，同(tong)樣(yang)的(de)應(ying)用(yong)程(cheng)序(xu)。突(tu)然(ran)間(jian)，這(zhe)種(zhong)令(ling)人(ren)愉(yu)快(kuai)的(de)連(lian)續(xu)性(xing)被(bei)打(da)斷(duan)了(le)。你(ni)的(de)焊(han)接(jie)強(qiang)度(du)下(xia)降(jiang)了(le)嗎(ma)？你(ni)看(kan)到(dao)太(tai)多(duo)溢(yi)料(liao)了(le)嗎(ma)？你(ni)的(de)焊(han)工(gong)在(zai)循(xun)環(huan)一(yi)開(kai)始(shi)就(jiu)過(guo)載(zai)了(le)嗎(ma)？在(zai)這(zhe)裏(li)，我(wo)們(men)將(jiang)討(tao)論(lun)一(yi)些(xie)看(kan)不(bu)見(jian)的(de)因(yin)素(su)，可(ke)以(yi)導(dao)致(zhi)您(nin)的(de)焊(han)接(jie)質(zhi)量(liang)突(tu)然(ran)變(bian)化(hua)，以(yi)及(ji)如(ru)何(he)防(fang)止(zhi)和(he)糾(jiu)正(zheng)它(ta)們(men)。
KNOW THE BASICS
了解基本知識
Ultrasonic welding works by applying a vibration at a frequency of 15 to 70 kHz to a plastic part. This vibration is generated through the use of piezoelectric ceramics in the transducer, that convert an electrical signal into mechanical motion. The transducer creates a vertical vibration that is then translated through the booster, and subsequently, the ultrasonic horn. The horn is typically designed to contact the part directly above the weld area so that the vibrations can travel though the upper part to the weld area.
超聲波焊接的工作方式是將頻率為15至70 kHz的de振zhen動dong施shi加jia到dao塑su料liao部bu件jian上shang。這zhe種zhong振zhen動dong是shi通tong過guo在zai換huan能neng器qi中zhong使shi用yong壓ya電dian陶tao瓷ci產chan生sheng的de，這zhe種zhong壓ya電dian陶tao瓷ci將jiang電dian信xin號hao轉zhuan化hua為wei機ji械xie運yun動dong。換huan能neng器qi產chan生sheng垂chui直zhi振zhen動dong，然ran後hou通tong過guo調tiao幅fu器qi和he隨sui後hou的de超chao聲sheng波bo焊han頭tou進jin行xing轉zhuan換huan。焊han頭tou通tong常chang被bei設she計ji成cheng與yu焊han縫feng上shang方fang的de部bu分fen直zhi接jie接jie觸chu，這zhe樣yang振zhen動dong就jiu可ke以yi通tong過guo上shang部bu到dao達da焊han縫feng區qu域yu。
The ultrasonic vibrations create cyclical strain at the weld area, which generates heat that melts the plastic in a restricted area and welds the two parts. Because the ultrasonic vibration acts on the entire weld surface, an energy director is often added to control the melting and reduce the amplitude necessary to achieve a weld.
超(chao)聲(sheng)波(bo)振(zhen)動(dong)在(zai)焊(han)接(jie)區(qu)域(yu)產(chan)生(sheng)周(zhou)期(qi)性(xing)應(ying)變(bian)，產(chan)生(sheng)熱(re)量(liang)，在(zai)限(xian)定(ding)區(qu)域(yu)內(nei)熔(rong)化(hua)塑(su)料(liao)並(bing)焊(han)接(jie)這(zhe)兩(liang)個(ge)部(bu)分(fen)。由(you)於(yu)超(chao)聲(sheng)波(bo)振(zhen)動(dong)作(zuo)用(yong)於(yu)整(zheng)個(ge)焊(han)縫(feng)表(biao)麵(mian)，通(tong)常(chang)會(hui)添(tian)加(jia)能(neng)量(liang)指(zhi)向(xiang)器(qi)來(lai)控(kong)製(zhi)熔(rong)融(rong)，降(jiang)低(di)達(da)到(dao)焊(han)接(jie)需(xu)要(yao)的(de)振(zhen)幅(fu)。
It is important to prevent metal-to-metal contact on your horn to increase its longevity. Because the horn is a tool with acoustical properties, users should be careful to preserve its structural integrity. Any nicks or gouges in the surface of the horn act as stress concentrators that can rapidly lead to cracks when the horn is in use.
zhongyaodeshifangzhijinshuyujinshujiechuzainidehantoushang，yiyanchangtadeshouming。youyuhantoushiyizhongjuyoushengxuetexingdegongju，yonghuyinggaixiaoxinbaochiqijiegouwanzhengxing。hantoubiaomianderenhequekouhuoquekoudouhuiqidaoyinglijizhongqidezuoyong，zaishiyongshihuixunsudaozhiliewen。
WARNING SIGNS警告
Many signs can indicate a change in your welding process. Some indications of a problem with your part include decreased weld strength, increased flash, and the appearance of cosmetic damage. Some things that signify a problem with the welder or ultrasonic horn are an increased wattage draw, a change in the sound of your weld (typically apparent on lower-frequency welders), and overloading.
許xu多duo跡ji象xiang表biao明ming你ni的de焊han接jie過guo程cheng發fa生sheng了le變bian化hua。你ni的de部bu分fen出chu現xian問wen題ti的de一yi些xie跡ji象xiang包bao括kuo焊han接jie強qiang度du下xia降jiang，溢yi料liao增zeng加jia，以yi及ji化hua妝zhuang品pin損sun壞huai的de外wai觀guan。有you些xie東dong西xi意yi味wei著zhe焊han工gong或huo超chao聲sheng波bo焊han頭tou有you問wen題ti，比bi如ru功gong率lv的de增zeng加jia，焊han縫feng聲sheng音yin的de變bian化hua(通常在低頻焊工上很明顯)，以及過載。
The first step in eliminating unseen problems is to record your welding setup. Make a “Weld Process” sheet that includes information such as your weld parameters (weld time, hold time, trigger mode, amplitude); manual settings (thruster height, pressure); and the critical dimensions of your part (diameter and energy-director/shear-joint size). Also include photos of the welder, showing the alignment and design of the horn and fixture. Refer to this document when problems arise—it may save you a lot of time and trouble.
消除未見問題的第一步是記錄焊接設置。製作“焊接過程”表格，包括焊接參數(焊接時間、保持時間、觸發模式、幅度)；手動設置(推進器高度、壓力)；以及零件的臨界尺寸(直徑和能量導向/剪切接頭尺寸)。還包括焊機的照片，顯示了角和夾具的對準和設計。當出現問題時，請參考這份文件-它可以為你節省很多時間和麻煩。
There are many not-so obvious factors that can negatively impact your weld quality. One of the most frequent causes of problems in a long-running process is wear on the mold that produces the parts to be joined. This is a slow, but sure, event in any molding process. Because most joint designs are relatively small compared with the size of the overall part, changes in their size or shape may go largely unnoticed. For many applications, a change in shear width from 0.016 in. to 0.020 in. can make a huge difference in weld quality. Such changes can be caused by just 0.002 in. of mold wear on each part.
有you許xu多duo不bu那na麼me明ming顯xian的de因yin素su會hui對dui你ni的de焊han接jie質zhi量liang產chan生sheng負fu麵mian影ying響xiang。在zai一yi個ge長chang期qi運yun行xing的de過guo程cheng中zhong，常chang見jian的de問wen題ti之zhi一yi是shi模mo具ju上shang的de磨mo損sun，該gai模mo具ju生sheng產chan要yao連lian接jie的de零ling件jian。這zhe是shi一yi個ge緩huan慢man，但dan肯ken定ding的de，事shi件jian，在zai任ren何he成cheng型xing過guo程cheng。因yin為wei與yu整zheng體ti的de尺chi寸cun相xiang比bi，大da多duo數shu的de連lian接jie設she計ji都dou相xiang對dui較jiao小xiao，所suo以yi它ta們men的de大da小xiao或huo形xing狀zhuang的de變bian化hua可ke能neng在zai很hen大da程cheng度du上shang沒mei有you被bei注zhu意yi到dao。對dui於yu許xu多duo應ying用yong程cheng序xu，剪jian切qie寬kuan度du從cong0.016英寸改變。0.020英寸。會對焊接質量產生巨大影響。這樣的變化可能是由0.002的。模具磨損的每個部分。
Another important factor is environmental changes such as ambient heat, cold, or humidity. Humidity is a particular concern if you are using a hydrophilic material such as nylon, polycarbonate, or polysulfone. Very cold temperatures can cause polymers to become brittle, which may cause them to crack rather than weld at a normal welding pressure. High heat can lead to longer solidification times, causing problems if you are working with short hold times.
另一個重要因素是環境變化，如環境熱、冷或濕度。如果您使用的是親水性材料，如尼龍、聚ju碳tan酸suan酯zhi或huo聚ju碸feng，濕shi度du是shi一yi個ge特te別bie關guan注zhu的de問wen題ti。非fei常chang冷leng的de溫wen度du會hui導dao致zhi聚ju合he物wu變bian得de脆cui性xing，這zhe可ke能neng導dao致zhi它ta們men開kai裂lie，而er不bu是shi在zai正zheng常chang的de焊han接jie壓ya力li下xia焊han接jie。高gao熱re量liang會hui導dao致zhi更geng長chang的de凝ning固gu時shi間jian，如ru果guo你ni的de工gong作zuo時shi間jian很hen短duan，就jiu會hui產chan生sheng問wen題ti。
Some materials are less sensitive to process changes. Try switching to an easily welded material, like ABS, to achieve greater consistency in your process.
有些材料對工藝變化不太敏感。嚐試切換到容易焊接的材料，如ABS，以實現更大的一致性在您的過程。
Probably one of the most overlooked factors contributing to welding problems is changes in the time from molding the part to welding the part. Proper ultrasonic welding setup can be drastically different when welding “cold” parts as opposed to welding “hot” parts. It is generally not a good idea to weld “cold” parts to “hot” parts.
可能導致焊接問題的被忽視的因素之一是從成型到焊接的時間的變化。當焊接“冷”件時，適當的超聲波焊接裝置可能會與焊接“熱”零件大不相同。通常情況下，把“冷”部分焊接到“熱”部分並不是一個好主意。
If at all possible, leave plenty of time for the part to cool after molding before welding. “Hot” parts are more difficult to control and can cause inconsistency in your weld process. Also, try to perform the welding operation in a climate-controlled environment to eliminate seasonal effects on your process. This is especially important in humid regions.
如果可能的話，在焊接前留出足夠的時間讓零件在成型後冷卻。“熱”部bu分fen更geng難nan控kong製zhi，並bing可ke能neng造zao成cheng不bu一yi致zhi的de焊han接jie過guo程cheng。此ci外wai，嚐chang試shi在zai氣qi候hou控kong製zhi的de環huan境jing中zhong執zhi行xing焊han接jie操cao作zuo，以yi消xiao除chu對dui您nin的de過guo程cheng的de季ji節jie性xing影ying響xiang。這zhe在zai潮chao濕shi地di區qu尤you為wei重zhong要yao。
MORE FACTORS TO CHECK
更多的因素需要檢查
If you know it is not your parts causing the problems, it could be your ultrasonic tooling. Occasionally a horn will develop a crack. While most horns will not run at all after forming a crack, some do. Those will often emit a high-pitched ringing sound or run at a higher wattage than normal. It is very important to discontinue use of a cracked horn because it tends to put excess stress on the transducer and can lead to broken piezoelectric ceramics.
如ru果guo你ni知zhi道dao不bu是shi你ni的de零ling件jian造zao成cheng了le問wen題ti，它ta可ke能neng是shi你ni的de超chao聲sheng波bo工gong具ju。有you時shi喇la叭ba會hui裂lie開kai。雖sui然ran大da多duo數shu角jiao在zai形xing成cheng裂lie縫feng後hou根gen本ben不bu會hui運yun行xing，但dan有you些xie則ze會hui。它ta們men通tong常chang會hui發fa出chu高gao音yin調tiao的de振zhen鈴ling聲sheng或huo以yi比bi正zheng常chang更geng高gao的de瓦wa特te數shu運yun行xing.停止使用有裂紋的喇叭是非常重要的，因為它會對換能器施加過多的應力，從而導致壓電陶瓷的斷裂。
Probably the easiest diagnostic test is to mix-and-match your ultrasonic stack if you have multiple welders of the same frequency. Try the horn with a transducer and booster that have been working well. If all is good after this switch, then you know the horn is not the problem. Likewise, you can put a working stack in a questionable welding machine. This is a quick and easy way to locate the trouble spot in your machine without any special equipment.
kenengjiandandezhenduanceshishihunhehepipeinidechaoshengboduidie，ruguoniyouduogexiangtongpinlvdehangong。yonghuannengqihezhutuiqishiyixialaba，tamenyizhigongzuodehenhao。ruguozhegekaiguanhouyiqiedouhao，namenijiuzhidaolababushiwenti。tongyang，niyekeyibayigegongzuodeduidiezaiyigeyouwentidehanjiejiqizhong。zheshiyizhongkuaisu、簡便的方法，可以在沒有任何特殊設備的情況下找到機器上的故障點。
If you find that the problem is your horn, check it for cracks. To locate cracks in a horn, spray it with a foaming cleaner. Then use the test feature on your welder to introduce short bursts of ultrasonic energy into the horn. The cleaner will collect in the crack and turn a blackish color. WD-40 oil can be used if a foaming cleaner is not available.
如(ru)果(guo)你(ni)發(fa)現(xian)問(wen)題(ti)是(shi)你(ni)的(de)喇(la)叭(ba)，檢(jian)查(zha)它(ta)是(shi)否(fou)有(you)裂(lie)縫(feng)。若(ruo)要(yao)找(zhao)出(chu)喇(la)叭(ba)中(zhong)的(de)裂(lie)縫(feng)，請(qing)用(yong)泡(pao)沫(mo)清(qing)潔(jie)劑(ji)噴(pen)灑(sa)。然(ran)後(hou)利(li)用(yong)你(ni)的(de)焊(han)機(ji)上(shang)的(de)測(ce)試(shi)特(te)性(xing)，在(zai)喇(la)叭(ba)中(zhong)引(yin)入(ru)短(duan)脈(mai)衝(chong)超(chao)聲(sheng)波(bo)能(neng)量(liang)。清(qing)潔(jie)工(gong)會(hui)在(zai)裂(lie)縫(feng)中(zhong)收(shou)集(ji)，並(bing)使(shi)顏(yan)色(se)變(bian)黑(hei)。如(ru)果(guo)沒(mei)有(you)泡(pao)沫(mo)清(qing)潔(jie)劑(ji)，可(ke)以(yi)使(shi)用(yong)WD-40油。
Finally, the welding fixture has a significant effect on the accuracy and precision of your welds. Make sure the fixture is providing support to the entire joint area, and that there is no room for misalignment of parts during loading. When welding softer materials such as polyethylene and polypropylene, be sure that there is support around the joint area in both lateral and vertical directions. Soft materials tend to deform outwards, which will hinder or prevent proper welding.
hanjiejiajuduihanfengdejingduhejingduyouzhezhongyaodeyingxiang。quebaojiajuweizhenggelianjiequyutigongzhichi，bingqiezaizhuanghuoguochengzhongmeiyoulingjianbuduiqidekongjian。danghanjiejiaoruandecailiao，rujuyixihejubingxi，quebaozaijiefengquyuzhouweiyouhengxianghezongxiangdezhicheng。ruancailiaoqingxiangyuxiangwaibianxing，zhejiangfangaihuozuzhishidangdehanjie。
關於作者
米蘭達·馬庫斯，伊利諾伊州聖查爾斯杜卡內智能組裝解決方案的應用工程師，廣泛從事超聲波和旋轉焊接工藝，並為SPE年度技術會議(ANTEC)合著了三份技術論文。馬庫斯還合著了一本教科書的一章。她歡迎在internet或(630)797-4937上提問。
ABOUT THE AUTHOR
Miranda Marcus, applications engineer at Dukane Intelligent Assembly Solutions in St. Charles, Ill., has worked extensively in ultrasonic and spin welding processes and has coauthored three technical papers for the SPE Annual Technical Conference (ANTEC). Marcus has also coauthored a chapter of a textbook. She welcomes questions at internet or (630) 797-4937.