草榴短视频

Young scientists of the Department of Nanostructured, Fiber and Composite Materials named after A.I. Meos of St. Petersburg State University of Industrial Technologies and Design (草榴短视频) Olga Gladunova and Natalia Lukicheva as a part of the group of scientists of the leading universities of the country and experts in the field of carbon fibers and composite materials at the invitation of ANO 鈥淚nformation Center of Nuclear Industry鈥� and Composite Division of the State Corporation 鈥淩osatom鈥� visited the production line of the enterprise 鈥淎LABUGA-VOLOKNO鈥�. Here is what the scientists of the University of Industrial Technologies and Design told about their trip.

Let's dive into the history.

The plant is located in the special economic zone 鈥淎labuga鈥� in the Republic of Tatarstan and includes three production facilities: synthesis of polyacrylonitrile (PAN), molding of PAN-fiber - precursor for carbon fiber and carbon fiber production itself.

The opening of the carbon fiber production shop took place in 2015. It became a landmark event for the domestic industry and an important step in the implementation of the state import substitution program. In 2021, the production of polyacrylonitrile precursor was launched there, in a neighboring workshop.

Today the capacity of the PAN precursor production line is up to 5 thousand tons per year. The capacity of the production line for carbon fiber of different denominations is up to 1.2 thousand tons per year.

PAN or gone.

鈥�This project was not very much believed by everyone, many doubted. Well, first of all, they thought that in principle it is impossible to build a high-tech production from scratch in Russia: the technological base will not allow, there are no people, there is no production chain.... Nevertheless, we managed to do it,鈥� said Alexey Likhachev, Director General of Rosatom State Corporation, at the launching ceremony of the PAN-precursor plant.

The technological process of PAN fiber production starts with synthesis of fiber-forming polymer - polyacrylonitrile - in the suspension polymerization shop. Modern equipment allows to obtain high quality polymer with low polydipersity (narrow range of molecular-mass distribution). The polymer is dried and stored in silos.

To manufacture the precursor, PAN fiber, the polymer, which looks like flour, is dissolved in dimethylacetamide. The resulting spinning solution is filtered, dehumidified and fed to the next stage - molding. The ready spinning solution is squeezed through the holes in the dies and thousands of thin jets fall into the precipitation (coagulation) bath. Then the fiber is washed from the solvent in several washing baths, followed by the stages of fiber orientation drawing and application of special lubricants. Finished PAN fibers are spooled onto spools weighing up to 300 kg each.

Stages of orientational drawing are determinant for obtaining qualitative PAN precursor with highly oriented structure of macromolecules and minimal irregularity in diameter. There is a connection between strength of PAN-fiber and carbon fiber, because precursor determines 70 % of qualitative characteristics of carbon fiber.

Carbon fiber. Cut off all unnecessary!

Production of carbon fiber is a single technological line 250 m long and 3 m wide, where the initial raw material, PAN-fiber, is subjected to oxidation, high-temperature and surface treatment, application.

At the initial stage, the PAN fiber is subjected to relatively long heating in air to a temperature of 300 掳C. During such consecutive heat treatment (thermo-oxidation) in 6 furnaces polymer structurization takes place, i.e. rearrangement of linear PAN macromolecules into molecules with ladder structure. This process is considered as the initial stage of polymer structure transformation into carbon-graphite structure. The duration of thermal oxidation is one of the most important parameters determining the quality of future carbon fibers. Also of particular importance is the fiber drawing during the thermo-oxidation process, which contributes to the orientation of the prestructures.

This is followed by 鈥渓ow-temperature鈥� up to 800 掳C and 鈥渉igh-temperature鈥� carbonization stages up to 1500 掳C in an inert gas environment. At temperatures from 400 to 800 掳C the main loss of fiber mass occurs, almost all elements except nitrogen and carbon are detached. At temperatures from 600 to 1200 掳C the main elements of carbon fiber structure are formed and the remaining atoms (nitrogen) are removed. At temperatures of 1200-1500 掳C carbon fibers begin to possess high physical and mechanical properties, which are realized due to the formation of oriented graphite-like turbostable fibrils. The content of carbon atoms in carbon fibers after high-temperature treatment is 94-96 %.

Production of carbon fiber is a complex multistage process in which each stage is crucial for obtaining a high-quality product.

At the end of the technical tour the General Director of LLC 鈥淎LABUGA-VOLOKNO鈥� Gaberling Andrey Vladimirovich answered all the questions and shared his plans for the future. The plans include scaling of production and launch of additional production lines for PAN precursor and carbon fiber production; development of new generation of PAN precursors and carbon fiber with advanced characteristics; optimization of PAN precursor and carbon fiber production in order to reduce the cost of carbon fiber.