After Shi Wei took a few steps back, he stood still, stepped forward and back, and said confidently: "Mr. Yu, you have something to say." ”

Yu Fan's language was even more severe: "Isn't it? Mr. Shi, greed is not enough to swallow elephants, and in the end he will always find his own hardships. ”

Shi Wei said unconvinced: "Mr. Yu, don't spew blood, whether it's black or white, you have to say something, don't talk nonsense." ”

Yu Fan took a slight breath and said: "Our barrel seal cover is particular about the design, the words on the seal cover and the trademark on the side wall of the barrel are completely parallel, but you see, the words on the seal cover in this warehouse are not parallel, each has its own angle, which shows that these disposable seals have been opened!" ”

Shi Wei defended: "You sent the logistics from the main factory, after such a long distance, the road was bumpy, and now the logistics are all violent loading and unloading, maybe these barrels have experienced something on the road, and the position of the disposable sealing cover is normal." ”

Yu Fan continued: "Each cap is pressed by our special capper, and it is generally impossible to be turned. As he spoke, Yu Fan clasped the lid with his hand, and the sealing cover was very loose and could be rotated on it.

Yu Fan continued: "This is just one of them, the more important reason why I can determine that this seal has been opened is that this seal is not the original seal at all. ”

Shi Wei was startled, and even his assistant Li Boring could see Shi Wei's panic.

Yu Fan: "The font on this sealed lid is Songti. And the font on our genuine seal cover is a square font, which is licensed for commercial use, and we have paid for it. And the average knowledgeable design company does not dare to use this font when designing things. If I'm right, our previous safety cover was opened, and then replaced with this fake one. ”

Shi Wei continued to ask: "Then what am I doing when I have nothing to do with the safety cover?" That's a lot of work. ”

Yu Fan: "Mr. Shi, I haven't said that you changed this safety cover." ”

Shi Wei paused for a moment.

Yu Fan continued to say lightly: "The purpose of changing the lid is very simple, that is, to open the lid of the barrel and add something to it. As he spoke, Yu Fan held up the sample he had just taken, and looked at eye level, and through the sunlight, the liquid appeared crystal clear.

Yu Fan: "What you bought from us is the cheapest HR-3S water-based transparent cutting fluid, the color of our stock solution should be slightly yellow, and the color of this liquid is dark yellow, obviously overpowered." ”

Shi Wei said: "Then why am I... He found that there was a problem with his wording, and immediately changed his words: "Then why does this person do things?" Could it be that a business competitor is maliciously sabotage? ”

Yu Fan smiled, glanced at everyone, and said: "Oleic acid and polyether defoamers are not cheap, no malicious competitors will be stupid enough to use these two things to destroy, if I, sprinkle a handful of salt, it is enough to destroy the entire cutting fluid system, and it will not change the color, and it is not easy to be discovered." ”

Guo Na asked curiously next to him: "Brother Yu, how do you know what you added, you can see it with your eyes?" ”

Yu Fan turned around and smiled mysteriously at Guo Na: "I didn't see it, I smelled it." Oleic acid has a distinctive lard taste, and polyether also has its own unique smell. ”

The crowd looked stunned.

Yu Fan continued to explain: "In addition to the happy flow mode, this is also my stunt, when I focus on the sense of smell, and then suddenly burst out of the sense of smell at that moment, I will ask about the smell that ordinary people can't smell, and through my experience, these flavors are separated and filtered, and I will know which one is which." In fact, all of us can learn this skill through training, but this skill is not always available, when you start to smell, the sense of smell will become less and less sensitive, which is a self-protection mechanism of the human body. That's why when we arrive at a new house, we suddenly have a very obvious sense of the smell of the house, and after a while, we don't smell the smell of the house. “

Shi Wei interrupted again: "Then, uh, what is the purpose of this person adding these things?" ”

Yu Fan: "It is said on the Internet that oleic acid can improve the lubrication performance of cutting fluid, but it will produce foam. So the purpose of the person who adds these things is to improve the lubrication through oleic acid, so that this ordinary cutting fluid can be sold at a high price, but in order to suppress the production of foam, some defoamers should be added, and polyether seems to be a good choice. ”

The roots of Shi Wei's ears began to turn red, and he began to pull the collar unconsciously.

Yu Fan continued: "It's a pity that he was very wrong, the deployment of cutting fluid is not simply to add a little thing to do well, pay attention to the balance of various properties, even if it is our cheapest product, it still implements this concept, and still has a high scientific and technological content." Although oleic acid can improve some lubrication, but the side effects are also obvious, oil and soap, more easy to corrode, in our system to add oil acid, is to drink water to quench thirst. The desire to use polyether defoamer to inhibit foam is even more superficial, the efficacy of polyether defoamer will decrease over time, especially when the PH value becomes low, when below a certain value, the effect of the defoamer is completely lost, and the previously added oleic acid will cause rancidity and PH value decrease. So there was a situation that Mr. Shi just said, it was okay at first, and the more you used the foam, the more you used. “

Shi Wei didn't dare to answer again.

Guo Na took over: "I understand, in fact, the reason for all this is that a layman, in order to increase his own interests, he self-righteously added things to it, and wanted to make high-end products and sell them for more money, but he shot himself in the foot." ”

Yu Fan nodded to Guo Na, and said earnestly: "Your reasoning is logical. But as chemists, we only look at real evidence and don't speculate. As psychologists, we don't directly put the information of the suspect into the clues, so that you will feel that the person being suspected is the ultimate offender no matter how you look at it. Instead, the suspect should always be treated as X, through evidence clues and psychological behavior logic, list the equations, and finally solve the equations to get the results. ”

Guo Na nodded with deep understanding. It turns out that this is the psychochemist.

Yu Fan turned his head sideways to everyone and said, "Mr. Shi, don't worry about it first. The evidence is clearly inconclusive, and everything I have just done is a preliminary reasoning. We still have some data to add to the equation to solve, and this is the last data we need. Yu Fan shook the sample bottle. When I go back and do a component analysis, I'll see if my reasoning is correct. Finally, I will go to the end user to inquire whether the product model you sell is HR-3S and whether the price is in line with the market price, and I think the truth will be revealed. ”

Shi Wei stood in place, looking dejected.