Last month, when I visited a dairy company in Inner Mongolia, the workshop director, Lao Ma, pulled me straight to the production line: "Your volumetric metering equipment is really amazing! Before, we had to sample thirty or forty cans after each batch of canning, but now the error of sampling ten cans is no more than half a spoonful!" Hearing this, I touched the milk powder industry packaging machine developed by our factory, and I was as proud as if my own child had scored full marks.
"Gram anxiety" in the milk powder industry
Everyone in this industry knows that the biggest headache for packaging machines in the milk powder industry is metering accuracy. The fluidity of milk powder is sometimes good and sometimes bad. When canning, it is either agglomerated or dusty. In the industry exhibition a few years ago, I saw some manufacturers using weighing measurement. The accuracy is high, but the cost of the equipment is enough to buy three ordinary packaging machines. After three months of squatting in the milk powder workshop, our factory's technical team found that: in fact, 90% of dairy companies do not want laboratory-level accuracy, but a stable and controllable ±0.5% error range. Just like what Lao Ma said: "The error exceeds 1%,
"Stupid method" turns into a trick
In order to solve the problem of milk powder hanging on the wall that year, we turned the laboratory into a "milk powder playground". Technician Xiao Zhou invented the "three-temperature test method" - filling milk powder at room temperature, low temperature and high temperature respectively. It was found that the measurement error jumped by 0.2% for every 5°C increase in temperature.
Now our milk powder industry packaging machine has an inconspicuous small device: hopper temperature compensator. The principle is simple, that is, to automatically adjust the screw feeding speed according to the real-time temperature, but it is this trick that improves the canning stability during spring and summer production by 60%.
Chemical reaction of servo motor + "memory metal"
Go When we renovated old equipment for a customer in Xinjiang in 2017, their workshop was 1,800 meters higher than the plain. The originally precise metering screw began to "gasp" when it reached the plateau - the change in air pressure caused the fluctuating degree of milk powder.
We changed the plan overnight, replaced the ordinary motor with a servo motor with pressure feedback, and added a compensation ring made of shape memory alloy in the metering cavity. Guess what? Last week, the customer sent the data, and the canning error of different batches of milk powder was firmly locked within the red line of ±0.5%.
The "Precision Long March" from the laboratory to the assembly line
Last month, when debugging the new machine in the workshop, the quality inspector Xiao Zhang took a vernier caliper and asked seriously: "Mr. Li, can the gap of this metering cavity be reduced by 0.03 mm?" I smiled and patted him on the shoulder: "You are more serious than the milk powder particles! ”
But it is this kind of fighting spirit that has enabled our milk powder industry packaging machines to develop unique skills: the metering screw made of aviation aluminum has a laser-engraved anti-sticking texture thinner than a hair; the servo closed-loop control system adjusts the speed 200 times per second, which is ten times faster than the blink of an eye.
Conclusion
Now every time I see the line "canning accuracy ±0.5%" on the quality inspection report of the milk powder manufacturer, I think of the late night when I ate instant noodles in the laboratory three years ago. At that time, the old factory director stared at the metering module we changed to version 17 and said: "Making equipment is like making milk powder. The water temperature difference is one degree, and the taste is ten points different."
I have always remembered this. Next time if you pass by our workshop, you will hear the "click" metal collision sound mixed with the roar of the machine - that is the metering cavity opening and closing accurately, and it is also a technical poem we wrote for the milk powder industry packaging machine.
