78: Bringing his wife and children to Harbin Institute of Technology

He asked Professor Zhao for half a day off.

Professor Zhao didn't ask any further questions, only saying, "Finish up your notes."

At 8:30, Ye Bingwen rode his bicycle to the factory.

Master Li specially changed into a clean work uniform today, saying, "I can't let my colleagues at Harbin Military Engineering Institute laugh at me."

Wang Guoqiang also came over from the purchasing department, carrying a notebook in his hand.

"Section Chief Wang, don't be nervous."

Ye Bingwen said.

"He's just a student, not a leader inspecting him."

"The students are also students of Harbin Military Engineering Institute."

Wang Guoqiang opened the notebook.

"I need to write down everything he said so I can follow it in the future."

At 9:00 AM sharp, a green Jeep stopped at the factory gate.

The car door opened, and a young man in his early twenties, wearing black-rimmed glasses, stepped out.

The work clothes had the words "Harbin Military Engineering Institute" printed on the chest.

He was carrying a canvas tool bag.

Ye Bingwen went to greet him.

"Hello, I am Ye Bingwen."

Hello.

The young man quickly put down his toolbox and reached out his hand.

"My name is Chen An, and I'm Professor Cai's student. Professor Cai asked me to come and assist you with your work."

"Welcome, welcome. You must be tired from your journey."

"It wasn't hard work, I came by car."

Chen An smiled, looking a little nervous.

Ye Bingwen led him into the workshop.

Liu Xiaojun, Master Li, and Wang Guoqiang were all standing inside, staring at Chen An.

Chen An felt a little embarrassed being stared at by so many people.

"Don't be nervous, everyone. I'm just a student. Professor Cai said you're doing a trial production of composite materials, and he asked me to help out."

Ye Bingwen poured him a glass of water and asked him to sit down and catch his breath.

Chen An didn't sit down; he took a sip of water and then walked around the workshop.

He looked very carefully, examining each piece of equipment closely.

"Director Ye, did you modify this press yourself?"

He squatted in front of the press, looking up at the nameplate on it.

"Yes. It was an old piece of equipment. We repaired it ourselves, replaced the seals, and modified the heating system."

Chen An stood up and looked at the control box of the heating system again.

Ye Bingwen made the control box himself, which contained several relays and a temperature controller.

It looks a bit rudimentary, but the route is laid out in a very orderly manner.

"What level of temperature control accuracy can be achieved?"

Chen An asked.

"Plus or minus five degrees."

Ye Bingwen said.

Chen An frowned.

"Five degrees is a bit too high. The curing temperature window for phenolic resin is very narrow; plus or minus two degrees is safer."

"That's why we need you to come."

Ye Bingwen said.

"If the equipment isn't precise enough, we can compensate with the process. You adjust the process parameters, and we'll cooperate."

Chen An nodded.

He opened the toolbox and took out a few items.

"Professor Cai asked me to bring this. It's a small sample of phenolic resin and curing agent."

"Let's make a few small test pieces first to get a feel for the process parameters."

He handed the documents to Ye Bingwen.

Ye Bingwen took it and flipped through it. It was a handwritten process instruction manual, with each step written very clearly.

Professor Cai said to try this plan first. If it doesn't work, we can adjust it.

"Okay. Xiaojun, come here."

Liu Xiaojun quickly came over.

Ye Bingwen handed him the documents.

"Write down every word Chen says, and ask him if you can't remember them. Chen, I'm entrusting this apprentice to you. Please teach him well."

Chen An glanced at Liu Xiaojun and smiled.

"Okay, no problem. I'm not some Engineer Chen, just call me Xiao Chen."

Liu Xiaojun grinned.

Ye Bingwen accompanied Chen An on a tour of the workshop, going over the process flow roughly.

"Chen—Xiao Chen, do you think we can produce a qualified product with our current conditions?"

Chen An thought for a moment.

"It's hard to say. Composite materials are highly sensitive to processing conditions; even a slight deviation in temperature, pressure, or time can make a difference."

"The results are all different. But Professor Cai said that your application scenario is very suitable for verification."

"Military products are produced in small batches and have high requirements for material performance, which is where the advantages of composite materials can be fully utilized."

"Then let's give it a try."

Ye Bingwen said.

At noon, Ye Bingwen treated Chen An to a meal at the factory.

Chef Li specially asked the cafeteria to cook two extra dishes and also opened a bottle of baijiu (Chinese liquor).

Chen An doesn't drink alcohol, saying he still has work to do in the afternoon.

Ye Bingwen did not force him.

After finishing his meal, Chen An went straight to the workshop.

He called Liu Xiaojun over, and the two of them squatted down next to the press and began to adjust the equipment.

Ye Bingwen watched for a while and saw that he picked it up quickly, which made him feel much more at ease.

He told Wang Guoqiang to "take good care of Engineer Chen" and then rode his bike back to school.

I have Professor Zhao's class this afternoon, and I can't miss it.

During class, Ye Bingwen was still thinking about things at the factory.

He flipped through the process instruction manual that Chen An brought and could basically understand it.

In his previous life at Peking University, he had some contact with composite materials, but not much.

At that time, he mainly worked on mechanical dynamics, and the materials were handled by the collaborating units.

Professor Zhao was speaking loudly on the podium about the fatigue strength of mechanical parts.

Ye Bingwen brought his thoughts back and began to take notes diligently.

The bell rang, and Professor Zhao called him over.

"Ye Bingwen, please stay behind."

Ye Bingwen walked to the edge of the podium.

Professor Zhao was tidying up his lecture notes, without even looking up.

"Did you take the morning off?"

"Yes. A graduate student from Harbin Military Engineering Institute came to the factory, and I made some arrangements."

Professor Zhao looked up and glanced at him.

"Professor Cai told me that composite materials are a good thing, but you shouldn't focus on one aspect while neglecting others."

"Your priority now is to do well on your final exams; everything else is secondary."

"I know, Professor Zhao."

"Good to know."

Professor Zhao waved his hand.

"Go."

After leaving school, Ye Bingwen went to the factory.

Inside the workshop, Chen An and Liu Xiaojun were still busy.

The press has been heated up, and the pointer of the temperature gauge is swinging back and forth around the set value.

Chen An squatted in front of the control box and drew a temperature curve on a piece of paper with a pen.

"Director Ye, look."

He handed the paper over.

A curve was drawn on the paper, showing the temperature fluctuating around the set value by about three degrees.

"This is the temperature curve under no-load conditions. Once the mold is installed and the material is added, the temperature fluctuations will be even greater. I estimate it will be within plus or minus five degrees."

Ye Bingwen looked at the curve.

Is there any way to reduce the volatility?

"Yes. Add a PID controller."

Chen An said.

"But your current control box is a relay type, controlled by a switch, so the temperature will naturally fluctuate."

"Switching to PID control can keep the temperature within ±1 degree."

How much does a PID controller cost?

"It's not cheap. But you can make it yourself. Professor Cai's lab has the blueprints, and I can make one for you."

Ye Bingwen thought for a moment.

"Do it. Make a list of what materials you need, and I'll have someone buy them."

Chen An wrote a list on a piece of paper and handed it over.

Ye Bingwen took a look and found that they were all common electronic components that could be bought at hardware stores in the city.