It's the peak of spring, the vegetation is flourishing, and some things that couldn't be done in winter can finally be done, such as making paper.

The papermaking technology had been perfected as early as last winter, but due to the limited season, it could not go any further.

All the paper made from last year to now is hemp paper. Now that the weather is getting warmer, all kinds of grass and bark can be found.

Li Mengxi asked the papermaking craftsmen which grasses or barks were better for making paper. As a result, the craftsmen gave different answers. Li Mengxi realized that his papermaking skills had far surpassed those of the craftsmen, and the craftsmen's experience was no longer enough to draw on.

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Li Mengxi didn't know what material was best for making paper, but he knew how to test it.

The order was once again issued to the cavalry. Li Mengxi ordered the cavalry to go out and collect all the vegetation they could find, whether it was trees, grass, vines, wild flowers or wild vegetables, as long as it was vegetation. Moreover, he specifically emphasized that all collected

The materials cannot be mixed.

Last time, the cavalrymen were reprimanded for not doing what they were asked to do. This time they went out again, and the cavalrymen were much more cautious and meticulous.

Nearly two hundred cavalrymen scattered out of the city and went looking for vegetation.

According to Li Mengxi's request, all grass and trees were collected. Some cavalrymen encountered a grass ditch halfway out of the city. They dismounted and went to the grass ditch to cut a sack of grass and put it back.

Some people found trees and peeled off bark and branches, some chose to plant vines, some cut bamboo, and all kinds of busy work.

The cavalry were very efficient. In less than half a day, all kinds of raw materials were sent back in an endless stream.

Li Mengxi was in the yard, looking at more and more messy materials piled up in the yard, and he was in trouble at this time.

I don’t even know these grasses, tree barks, etc. I don’t even recognize them. How can I record and label them?

Li Mengxi had no choice but to find someone to help.

The carpenters came and helped distinguish part of it, while the remaining large part was mostly weed parts. The craftsmen had different opinions. A kind of weed can have three or five names.

At this time, Li Mengxi realized that the same grass has different names in different regions.

It was difficult to label all the vegetation. Just after finishing the work, another cavalryman came back carrying a large bundle of bark.

Li Mengxi looked at the greenery on the ground and thought that for papermaking, the materials should be dried in the sun. At this time, houses were being built everywhere in the city, and there was no place to dry grass. After much deliberation, only the city walls were suitable.

Later, Li Mengxi led people to move all the materials to the city wall, and then painted each section of the city wall with a kind of material, and labeled each place to prevent confusion.

The craftsmen were busy using ropes to tie up various materials and hang them on the battlements. Li Mengxi was thinking that if the materials were all dried, the grass would not look like it when it was dried. And because, what was needed this time

There are too many types of plants, and they may be repeated in the future. Therefore, they have to be classified from time to time. Sun-dried grass is not easy to distinguish.

At this time, a question arises: how to maintain the appearance of plants for a long time.

Li Mengxi thought of using a bowl to plant grass, but then he thought that a lot of grass would have no roots when cut back, so this method was useless.

Furthermore, Li Mengxi thought about how the specimen should be prepared, soaked in water? In grease? Or in alcohol?

Ginseng soaked in alcohol will still look like ginseng no matter how many years it is soaked. In addition to discoloration, alcohol has a strong preservation ability.

Thinking of this, Li Mengxi ran down to the city.

Coming up again, Li Mengxi and his men brought many jars filled with water. He was not rich in alcohol and could not afford alcohol.

Then, in the area where the materials were dried, Li Mengxi went to grab a handful of drying grass and stuffed it into jars at each area, and then put a jar for soaking the materials in one place.

The craftsmen watched Li Mengxi busy and placed the jars one by one in the corner, but they didn't understand.

After the material handling problem is solved, there is another problem that needs to be solved urgently, the utensil problem.

Last winter, the papermaking materials used at that time were limited, and there were not many cooking tools, so it didn't matter whether the vat for cooking pulp was larger or smaller.

However, this time is different. This time there is a huge testing demand. This time hundreds of materials have to be tested. The quality of the paper made from these hundreds of materials has to be compared. It is precise and subtle, and there can be no deviation.

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The urn for cooking the pulp should be larger or smaller, add more or less water, and the pulp should be thicker or thinner. This will all affect the strength of the paper. Therefore, you need to have a batch of utensils of exactly the same size.

According to Li Mengxi's understanding of pottery technology, clay embryos are manually kneaded, and the sizes vary and are difficult to be exactly the same. Therefore, another technology must be used.

Li Mengxi thought of casting iron and using molds to cast iron. A set of molds can cast hundreds of identical iron parts. This is the only method that can be mass-produced under current technical conditions.

Outside the city, where the kiln site is, the earthen kiln is still burning. When I look up, I can see black smoke billowing.

After thinking for a while, Li Mengxi went down to the kiln.

Li Mengxi found the head potter in the kiln and discussed with him whether he could use molds to make a batch of pottery of exactly the same size.

The head craftsman nodded without thinking, "We can do it, we just have to make a mold."

There are many ways to make molds, including wood, iron casting, clay firing, etc. Considering the trade-off between cost and speed, Li Mengxi finally chose to use wood to make the mold.

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At the carpenter camp, Li Mengxi discussed the technical details with the carpenters.

After the carpenters listened to Li Mengxi's request, someone said, "It's hard to find big wood. How about using wooden boards to make barrels?"

Li Mengxi thought for a moment, and it seemed easier to build a mold out of some thin wooden boards than to dig out a mold from a whole section of tree stump.

Another valuable and ingenious technology appeared, and Li Mengxi immediately wrote a military ticket and gave it to the carpenter.

After receiving the military ticket, the carpenter was stunned for a moment, then smiled.

It's always like this, every time the craftsmen don't realize the value of their few words, and the reward comes unexpectedly.

This chapter is not over yet, please click on the next page to continue reading! The technology of the mold has been determined. Just take a wooden board and piece it together to make a groove. Making a mold is much simpler than making a barrel, because there is no need to seal or put it together.

That’s it.

Regarding the shape of the mold, Li Mengxi thought that since the subsequent test required precise addition of sample and water, the instrument could be made more precise. The instrument could be made into a test tube shape and a long and slender tube, which would facilitate precise operation.

After determining the shape, Li Mengxi left the carpenter's camp and returned to the City Lord's Mansion. The courtyard of the City Lord's Mansion was filled with straw and rice seedlings.

After a while, the carpenters made the mold and sent it to the kiln.

The head of the kiln took the mold and was surprised when he saw that the mold was long and thin and had the same shape as a tube.

Although he was surprised, when he thought about the many strange things that military advisors did on a daily basis, the kiln leader did not ask any more questions and went about his business with the molds.

To make pottery, you first need to wash the clay, then shape it by hand, then trim it, dry it, and then fire it in a kiln, etc. A series of processes.

There was no shortage of materials in the kiln. In a short while, the potters made the first clay embryo according to the mold, then the second, and the third.

Soon, problems arose.

Because the mold is too slender, the clay embryo is also too slender. After the clay embryo is placed there, it will collapse and deform due to gravity.

The head of the kiln came over and looked at the deformed clay embryo. He couldn't help but frown. According to long-term experience, if the clay embryo is so slender and slender, once it is fired in the kiln, the water vapor will evaporate and then shrink, it will definitely deform and crack.

After hesitating for a moment, the leader of the kiln farm entered the city and came to the city lord's mansion.

In the City Lord's Mansion, Li Mengxi was labeling a bundle of bark. Seeing the person in charge of the kiln coming, Li Mengxi asked, "How is it? Is the mold ready?"

The head of the kiln explained the purpose of his visit and said that the mold was not working. As for why it was not working, Balabala talked a lot about it.

Li Mengxi frowned and listened. He understood that when the clay embryo was fired in the kiln, it would shrink. A three-foot-large embryo was only one foot long after it was burned, and it had to shrink by as much as two-thirds.

The mold is too slender and will easily deform and crack when it shrinks.

But why is it easy to deform and crack when it is slender? Li Mengxi frowned and thought.

Speaking of which, up to now, Li Mengxi has had enough contact with the soil. He led people to build earthen kangs, led people to set up heat treatment kilns, and led people to cross stoves in lakes. Especially when building earthen kangs, he was afraid that the kangs would not work properly.

It was strong enough to prevent people from falling off, so the arched shape was taken into consideration.

(Yes, arch!) Li Mengxi suddenly realized that he understood that the relationship between the shape of the clay embryo and cracking and deformation was that the stronger the shape of the clay embryo, the less likely it is to deform and crack.

If a cuboid clay embryo and a spherical clay embryo are burned in the same way, which one is more likely to crack? There is no doubt that the cuboid is far easier to crack than the sphere.

If you want to ask why, dome, eggshell, Sydney Opera House and so on.

As big as the eggshell is, the ball will be as big as it is.

After understanding this, Li Mengxi thought of a solution. Since the clay embryo that is too slender is easy to burn, then change the mold to an ordinary mold.

In view of the fact that the clay embryo will shrink significantly during the firing process, Li Mengxi realized that because the shrinkage is too large, when making the clay embryo, the humidity of the cement embryo will be very different if there is more water and less water, which can easily cause

When clay embryos of the same size are fired in the same kiln, one will be larger and the other smaller.

What's more, kilns are different from kiln to kiln, and the firepower of each kiln is also different, which is another unexpected variable.

Li Mengxi realized that it was easy to cast thousands or hundreds of identical iron pieces from ironware, but it was difficult to produce a batch of exactly the same pottery.

At this point, Li Mengxi remembered - [Big Industrial Technology].

The core principle of large-scale industrial technology is "discrete" in mathematical principles. Discrete, to simply describe it, is, assuming that the processing accuracy of a machine is 0.1 mm, then how to produce ultra-high-precision parts with an accuracy of 0.1000 mm

?

The answer is, directly produce 10,000 units.

Why is it enough to produce only 10,000 units?

Because when a machine with a processing accuracy of 0.1 mm is produced, the size of each part processed fluctuates around 0.1. The previous size may be 0.099, and the next size may be 0.11 or 0.111.

If you draw a function graph and look at it, you will find that the actual size is evenly distributed around the value 0.1.

When the number of parts produced reaches as many as 10,000, and when the number is so large, there are always one or two parts whose dimensions happen to be stuck to the accuracy of 0.1000.

Ever since, with a sufficient quantity, the ultra-high-precision part was produced.
To be continued...