The mi ma
(software translation)
Doctor of Engineering, Tsinghua University
906 people agreed
About the mask machine in the first half of this year, it really makes people feel "the world is really wonderful". I have only heard of similar scenes before, and it is my first time to experience them.
See a lot of comments, the mask machine is classified as a low-tech machine. Indeed, after the outbreak of the epidemic, many manufacturers, including many large garment factories, automobile factories and parts factories, electronic products factories, quickly mounted the line of masks and production at full capacity. The shelf of the mask machine belongs to a relatively simple non-standard automation production line, not to mention the large companies, dongguan several people of small automation companies within two or three weeks are also determined; But masks line core equipment, ultrasonic welding machine, is really need technology, super audio (generally more than twenty thousand times per second and, some also used fifteen thousand times) on the welding machine vibration and in the People's Daily life, all kinds of forced vibration of low frequency was completely different, need to welding machine each part size for precise design, guarantee the system work in its axial resonant frequency (typically the first ten order modal vibration mode), and the vibration of the output on the welding head end face evenly, after do this, still need to pay attention to: When the welder is working, it will generate heat and be subjected to continuous extrusion or impact load, the optimal operating frequency of the system will change, so a high-power power source that can monitor the output state and automatically adjust the frequency is needed. On the other hand, when the frame is put up, it is necessary to adjust various parameters, such as the welding time of ear belt and the holding time of pressure, as well as technical and physical work.
In addition, the dots, trademark marks and ear bands on the masks you see are processed by different types of ultrasonic welders, that is, welding together multiple layers of cloth and rubber bands. Ultrasonic welding machine is fast, and the connection process does not need glue, is environmentally friendly.
Think mask machines are easy? A lot of people fall on it.
Some people hoarding of piezoelectric ceramic piece (the inside of the ultrasonic welding machine core components of energy conversion) wu wear, or large orders for piezoelectric ceramic manufacturers make them unable to meet other customers, then his speculation in the market, as a result, a sell ten dollars at ordinary times (single set of welding machine generally need 4 pieces, a mask line will need about four sets of welding machines), to be fired more than 2000 in April, price one hundred times, and... By May, demand for mask machines had slowed, and the price of ceramic chips had collapsed, just as the stock market had collapsed. There is a saying in the stock market that "don't make the last penny," but when the stock market goes crazy, no one knows when the penultimate penny will appear.
The reason piezoelectric patches are a strategic resource is hyped is because other parts can be produced in a short period of time, but piezoelectric patches cannot. Generally, the performance of domestic piezoelectric patches should be stable after they are produced for a month. The piezoelectric patches of some cattle factories abroad will be stored in the warehouse for more than a year. But... Driven by interests, the market does not know how many low-quality piezoelectric pieces, anyway, most people do not know the industry, even do not know that piezoelectric ceramics is also a lot of brands, let alone by the standard test.
What do you look like when you're crazy? Barter. Yes, I never expected to see this primitive method of trading. I have a power supply, you have a piezoelectric piece, the za exchange, each save machine to sell.
There are a lot of people who like to do things over and over again. The family on the west wants a piezoelectric piece, the family on the west wants a welding head, the family on the South looks for a lug pole and the family on the North looks for a power source. All the resources that can be found are used. Moreover, even when the ultrasonic transducer is assembled, the screws are not twisted randomly, which requires a specific pre-tightening force. After the ultrasonic transducer is assembled, it usually needs to be placed for a few days before its performance is stable, but the market is too crazy, as long as it can be saved up, someone will buy it, can not be used again, and to rob, how to rob, private transfer without invoice.
Some people have some mechanical processing ability, see the structure of ultrasonic welder is simple, eager to try, how to do it? Copy! However, the ultrasonic thing, the size difference of a few tenths of a millimeter, or the material heat treatment process is different, the frequency difference is hundreds of kilohertz, and the appropriate welding bandwidth is also in the tens to tens of Hertz. However, the first wave of people, no matter how bad it is, have earned, because the market thieves crazy, behind the entry of people, a lot of production or hoarding a large number of parts, finally can not sell, had to sell the parts.
The last is the mask machine, at that time as long as not slow automation business probably all mixed in, if you can get the ultrasonic welder, the rest of the automation is not difficult, copy can be, online can download the drawings. The price of mask machine has increased several times, but it is still in short supply. It is often the case that the latter steal the orders from the previous customers at a high price. Later, the boss was afraid that others would grab the order, so he arranged for a few younger brothers to live and eat in the factory of mask machine and stare at them, and then immediately pull them away. It was quite interesting. A friend of mine who does non-standard automation once "complained" helplessly, "he took an order for two sets of mask lines and signed a contract, but one of them was just finished and had not been adjusted yet. Another boss dumped twice the cash and directly came to the truck and took it away.
Well, if you have the resources and the means to get a mask machine, then... You will find that debugging takes time. The equipment looks easy. Do you understand the welding process? Do you know how to adjust the welding time and holding time? The parameter setting is not reasonable, or the welding machine itself has a quality problem, it will not take long to break down. When the market is crazy, look for people to repair, then the market to ease a bit before there is better, as for the manufacturer's warranty, all see conscience and have time to manage you, because you then grab the goods when these conditions were not talked about, did not sign a contract, did not go to the formal payment procedures.
The domestic situation is such, after domestic saturation, small factories recognize deficit clearance, capable manufacturers get the corresponding certification to do export, but this wave of crazy operation after the product quality is not where to go, because the quality from the piezoelectric plate may be second. Then you have to find someone to debug and repair the equipment, this process is very complicated, once the fault means that this line can not be shipped for half a day or more days, put in Germany, the estimated cost is too high to accept.
So, Germany, with its highly developed manufacturing industry, can't make mask machines of its own? Of course, and the quality can be much better than ours. For the first wave of mask machines after the epidemic in China, many German welders, such as Hellman's, are used, but their usual price is 10 to 20 times that of domestic welders. But this kind of surprise research and development of things, The Germans can not do, you know that crazy time, China related industries of technical personnel work overtime every day, for a month or two consecutive, so... If you make money, it is also hard money, barely compensate for the impact of the epidemic; There are also a lot of people who put in a lot of manpower and material resources but ended up losing a lot of money. There are too many reasons. You can refer to the stock market, but it is much more exciting than the stock market I have experienced.
Now China masks capacity already came up, this wave of crazy, a lot of people the chance to gather together a lively, but the tide receded, the remaining or professional strength of the company, or they have been deep tillage technology in this field, or a large number of relevant raw materials preparation, or attaches great importance to the development of the value of feathers, no matter how crazy are not on the inferior product market (of course, only the truly knowledgeable talent points out product quality). Today, China has not only realized the freedom of masks for its own people, but also has the capacity to supply them to foreign countries. For developed countries, it is cheaper to import masks than to make them yourself.
Last but not least, if the labor is not expensive, the mask is actually a multi-layer cloth that can be sewn. In fact, it can also be made by hand with high-end customization. Each one is unique:
如何看德国口罩生产「去中国化」失败，开始大批进口中国口罩？
清华大学 工学博士
906 人赞同了该回答
关于今年上半年的口罩机，真的让人感觉“世界真奇妙”。以前只听说过类似的场面，第一次亲身经历，真的长见识了。
看很多评论里面，把口罩机归为低科技含量的机械。确实疫情爆发后很多厂家，包括很多大的服装厂、车厂及配件厂、电子产品厂等，迅速上马了口罩线并开足马力生产。口罩机的架子属于比较简单的非标自动化产线，不用说大公司，东莞几个人的小自动化公司两三周也搞得定；但是口罩线上的核心装备——超声焊机，真的是很需要技术含量的，超声频（一般每秒两万次及以上，某些焊机上也用一万五千次）的振动和人们日常生活中见到的各种低频的受迫振动完全不一样，需要对焊机每个部分尺寸进行精确设计，保证系统工作在其纵振谐振频率（一般都是第十几阶模态振型了），并且在焊头端面上输出均匀的振动，做到这点后，还需要注意：焊机工作时会发热，并且受到连续挤压或冲击载荷，系统的最佳工作频率会发生变化，所以需要能监测输出状态并自动调控频率的大功率电源。另一方面，架子搭起来，要调试好各种参数，比如耳带焊接时间和保压时间，也是技术活和体力活。
补充说明下，大家见到的口罩上那一排排小点点、商标印记、耳带等都是不同型号的超声焊机加工出来的，也就是把多层布料、橡皮筋等焊在一起。超声焊机速度快，且连接过程不需要胶水，是环保的。
认为口罩机很简单？很多人都是砸在这上面了。
有的人囤积压电陶瓷片（超声焊机里面的核心能量转换元件）捂着，或者给压电陶瓷厂家下大订单让其无法接其他客户，然后他在市场上炒作，结果，平时一片卖十几块钱（单套焊机一般需要4片，一条口罩线需要四套焊机左右），到了四月份被炒到2000多，涨价百倍，然后....到了五月，口罩机需求放缓，陶瓷片的价格暴跌，就像股市崩盘一样，不知道这里面多少人赚的盆满钵满，多少人亏得内裤都不剩。股市里有名言说“不赚最后一个铜板”，但是股市疯狂的时候，没人知道什么时候出现倒数第二个铜板。
压电片之所以成为战略资源被炒作，是因为，其他零件都可以短期内生产，而压电片不行。一般国产的压电片生产出来后要放置一个月性能才大概稳定，国外一些牛厂的压电片会先在仓库里保存一年以上。但是....利益驱使下，市场上不知道流入了多少劣质压电片，反正买的人大多不懂行，甚至都不知道压电陶瓷也是有很多牌号的，更不用说按标准检测了。
疯狂的时候什么样？以物易物，没错，我从没想到会见识这种原始交易方法。我有电源，你有压电片，那咱交换下，各自攒整机卖。
有很多喜欢折腾的人，东家求压电片，西家要焊头，南家找变幅杆，北家找电源，能找到的资源全用上，然后再找中家装配，这样弄出来的东西是很吓人的，要知道，各部分参数不一定匹配；而且就算是匹配的，超声换能器装配的时候，螺丝都不是随便拧的，需要达到特定的预紧力；超声换能器组装起来以后，一般也是要放置好多天性能才稳定，但是市场太疯狂，只要能攒起来就有人买，能不能用再说，而且要抢的，怎么抢，私人转账不用发票。
有人有些机械加工能力，看超声焊机的结构简单，就跃跃欲试，怎么搞呢？抄! 可是，超声这东西，尺寸差零点几毫米，或者材料热处理工艺不一样，频率就差几百上千赫兹，而合适焊接的带宽也就十几到几十赫兹。但是呢，第一波进来的人，不管做得多差都赚到了，因为市场贼疯狂，后面入场的人，很多生产或囤积了大量零部件，最后卖不出去，只得论斤卖零部件。
最后是口罩机，那段时间只要不迟钝的自动化商家估计都搀合进来了，如果你能搞到超声焊机，其他的自动化部分倒是不算难，照抄就可以，网上都能下载到图纸。口罩机价格翻了几倍依然供不应求，后来者出高价抢走之前客户的订单的情况屡屡发生，设备还没有调试就拉走；后来有老板怕别人抢单，安排几个小弟吃住在口罩机厂家盯着，装好立马拉走，挺有意思的。我一个做非标自动化的朋友，有一次很“无奈”地“抱怨”说：“他接了一个两套口罩线的订单，签过合同的，结果其中一条刚完工，还没调试完，被另一个老板甩下两倍的现金，直接来货车拉走了。”
好吧，如果你有足够的资源和手段搞到了口罩机，然后....你会发现调试很花时间，设备看上去不难，焊接工艺你懂吗？你知道焊接时间和保压时间怎么调吗？参数设置不合理，或者焊机本身质量有问题，用不了多久就坏了。市场疯狂的时候都找不来人维修的，后来市场缓和一点才有好转，至于售货厂家保修，全看良心以及有没有时间管你了，因为你当时抢货的时候这些条件都没谈呀，也没有签合同，也没有走正规付款程序呀。
国内的情况是这样，国内饱和后，小厂认亏清货，有能力的厂家拿到相应认证后做出口，但这一波疯狂操作后产品质量好不到哪里去吧，因为从压电片开始质量就可能是次的。然后你要找人调试和维修设备，这个过程很繁琐，一旦出故障就意味着这条线半天或多天不能出货，放在德国，估计成本高得接受不了。
那么，制造业高度发达的德国，自己做不了口罩机吗？当然可以，而且质量可以比我们的好很多，国内疫情后第一波口罩机，很多用的德国焊机，如海尔曼的，不过人家平时的价格就是国产焊机的一二十倍。但是这种突击研发的事情，德国人干不来的，要知道那段疯狂的时间，中国相关行业的技术人员天天加班的，连续一两个月，所以....如果赚了钱，也是辛苦钱，勉强补偿下因为疫情带来的影响吧；也有很多人投入大量人力物力最后反而亏了很多，那原因就太多了，可以参考股市，但比我经历过的股市刺激多了。
现在中国口罩产能早就上来了，这波疯狂中，很多人趁机凑一把热闹，但浪潮退去，剩下的还是专业实力强的公司，他们或一直在这个领域深耕技术，或有大量相关原材料准备，或重视研发爱惜羽毛、不管市场多疯狂都不投放劣质产品（当然也只有真正懂行的人才分的出产品质量)。时至今日，中国不仅实现了本国人民的口罩自由，也有余力供货给外国。对发达国家来说，与其自己造口罩，真心不如进口划算。
最后皮一下，如果不是劳动力贵，口罩其实也就是可以缝制的多层布料，其实也可以这样纯手工打造，高端定制，每一个都独一无二：
编辑于 5 小时前
