science

Kirza

Kirza is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Kirza rather than just read about it. In short: Kirza (Russian: кирза) is an early Russian type of artificial leather based on a multi-layer textile fabric, modified by membrane-like substances. It consisted of cotton, latex and rosin.

Key takeaways

Kirza belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Kirza to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Kirza from memory before moving on to harder problems.

Reference excerpt

Kirza (Russian: кирза) is an early Russian type of artificial leather based on a multi-layer textile fabric, modified by membrane-like substances. It consisted of cotton, latex and rosin. It was produced mainly in the Soviet Union. The surface of kirza imitates pig leather. The material is mainly used in the production of military boots, where it is a cheap and effective replacement for natural leather. It is also used in the production of belts for machinery and automobiles. The Kirza SK high boots were named by soldiers as 'shit trampers'. It is also used in holsters.

Etymology While some English dictionaries translate кирза as kersey, this is incorrect, as kersey is a material of natural origin known since the Middle Ages. However, kersey was used in the production of the first kirza. According to a popular legend, the name kirza is an acronym for Kirovskiy zavod (Kirov factory), a factory producing artificial leather located near Kirov. However, the actual name of the factory was IsKozh (an acronym for "Iskusstvennaya Kozha" - artificial leather), and the legend is simply an example of folk etymology.

History In 1904, Mikhail Pomortsev invented the original leather substitute. He used a mixture of egg yolk, rosin and paraffin wax to impregnate kersey. Despite receiving several awards in Russia and abroad, it was not used due to lobbying by leather boot manufacturers. It remained expensive, despite the demand, until the invention of synthetic latex in the early 1930s which replaced the initial impregnating mixture. During 1920s and 1930s, Aleksandr M. Khomutov and Ivan Plotnikov developed a new material called Kirza SK. Kirza SK is a pig leather imitation based on multi-layer coarse cotton fabric, impregnated by a film-forming synthetic rubber type substance involving a vacuum manufacturing process, which produced a fabric that is impervious to water, yet with a breathable membrane to let air through. Kirza was first used in 1936-1937 and authorized to replace leather goods in 1940. The Red Army trialed boots with kirza SK uppers during the Winter War but it proved unfit for winter conditions, and production was halted. In 1941, as technology improved, mass production was resumed to meet demand for army boots during the German invasion of the Soviet Union. Plotnikov became the chief engineer for the supply of kirza SK boots to the army. On 10 April 1942, Aleksandr Khomutov, Ivan Plotnikov and seven other specialists were awarded the 2nd Degree Stalin Prize for their invention of the new kirza production technology. By the end of the war, an estimated ten million Soviet soldiers were wearing kirza boots. Kirza has remained in production in Russia and in several other countries. About 85% of the kirza produced in Russia is used in military boots (including modern combat boots). Most modern kirza boots are produced from a combination of 85% kirza and 15% of specially prepared natural leather (the so-called yuft or Russia leather). About 150 million pairs of kirza footwear have been produced up to the present day.

Illustrations

Worked examples

Example 1 — a first encounter with Kirza

Start with the simplest possible case. Write down what Kirza claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Kirza before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Kirza ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Kirza

In research: Kirza appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Kirza in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Kirza is common in secondary-school and first-year university syllabi. It links to neighbouring topics Artificial leather, Footwear, Soviet Army, so understanding it makes those chapters shorter.
In everyday life: Look for Kirza outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Kirza in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Kirza means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Kirza out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Kirza in simple terms?

Kirza (Russian: кирза) is an early Russian type of artificial leather based on a multi-layer textile fabric, modified by membrane-like substances. It consisted of cotton, latex and rosin.

Why does Kirza matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Kirza?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Kirza.