Plant leaf plug. Cover tissue of secondary origin. Advantages of technical plug

The property of plants is growth throughout life.

All meristems are characterized by the ability to intensively divide,

their cells are small in size, closely packed together, cellular

the walls are thin (cellulose), the nuclei are large, and the vacuoles are small or completely absent.

After cell division, cells are able to differentiate, with one cell always remaining

in the meristem, and the other undergoes changes and participates in the formation of other structures.

Depending on the location, educational tissues are divided into: apical, lateral,

insertion and wound.

Apical (apical ) the meristem is located at the top of the axial organs (the tip of the shoot or the tip of the root), this is the primary plant tissue, as it is formed from embryonic tissues. It determines the vertical growth of the plant.

Lateral (lateral) the meristem is located on the periphery of the axial organs, forms a cylinder, called cambium. it ensures the growth of organs in thickness. Cambium cells are arranged in a single layer, they are flat, located between the xylem and phloem. Participates in the formation of annual rings in perennial plants.

Insert (intercalary) The meristem is located in the lower part of the internodes or the base of the leaves and determines the vertical intercalary growth of plants. well developed in cereal plants, it functions for a short time, so the growth of cereals and leaf growth stops in the first half of the growing season.

wound The meristem can arise in any part of the plant, where tissue damage occurs, and develops, as a rule, from parenchyma cells.

Today we will talk about integumentary tissues; they are located on the surface of plant organs and protect them from drying out, overheating, mechanical and chemical influences. In addition, it provides gas exchange and transpiration (evaporation of water). There are three main groups depending on the time and place of their origin:

- epidermis, plug, crust.

A feature of these tissues is the presence of highly thickened cell walls, as a result of which the gas- and water-impermeable substances lignin, subberin or cutin are deposited in them. This often leads to the death of the protoplast. The cells are tightly adjacent to each other, so there are no intercellular spaces.

Epidermis

The epidermis (skin) is a living tissue, it is located on the surface of young parts of plants (annual shoots, leaves, petals, fruits). This is a living tissue formed by one layer of flattened cells; their walls have a tortuous shape, which contributes to better closure with each other. The cells are colorless.

?1. Why do epidermal cells lack chlorophyll? (Answer at the end of the post)

The cell walls are not evenly thickened, the outer ones are very thick and covered with a layer of cutin, and the inner ones are thin cellulose.

?2 . Why do epidermal cells have unevenly thickened walls?

For gas exchange and transpiration, the epidermis has specialized structures - stomata. This is a slit-like opening bordered by guard cells. They are bean-shaped, green because they contain chlorophyll, and the internal (facing the slit) walls are thickened. Stomata are most often located on the underside of the leaf.

?3. Which plants have all the stomata on the upper side of the leaves? Why?

ANSWERS

?1 . In order not to impede the penetration of sunlight, the epidermis is colorless to the underlying photosynthetic tissues.

?2 . The outer walls provide protection from external influences, and the inner walls carry out metabolism, since the epidermis does not have chloroplasts and, therefore, is not capable of photosynthesis. Nutrients come from the underlying cells.

?3 . Stomata are located on the upper side of those leaves that lie on the water, that is, in aquatic plants, since the release of gases downward is impossible.

Conductive fabrics. Epidermis

Conducting tissues are complex, since they consist of several types of cells, their structure has an elongated (tubular) shape, and is penetrated by numerous pores. The presence of holes in the end (lower or upper) sections provides vertical transport, and pores on the side surfaces facilitate the flow of water in the radial direction. Conductive tissues include xylem and phloem. They are found only in fern-like and seed-bearing plants. Conductive tissue contains both dead and living cells
Xylem (wood)- This is dead tissue. Includes the main structural components (trachea and tracheids), wood parenchyma and wood fibers. It performs both a supporting and conductive function in the plant - water and mineral salts move up the plant through it.
Tracheids – dead single spindle-shaped cells. The walls are greatly thickened due to the deposition of lignin. A special feature of tracheids is the presence of bordered pores in their walls. Their ends overlap, giving the plant the necessary strength. Water moves through the empty lumens of the tracheids, without encountering any interference in the form of cellular contents on its way; from one tracheid to another it is transmitted through the pores.
In angiosperms, tracheids have evolved into vessels (trachea). These are very long tubes formed as a result of the “joining” of a number of cells; the remains of the end partitions are still preserved in the vessels in the form of rims-perforations. The sizes of the vessels vary from several centimeters to several meters. In the first vessels of protoxylem to form, lignin accumulates in rings or in a spiral. This allows the vessel to continue to stretch as it grows. In metaxylem vessels, lignin is concentrated more densely - this is an ideal “water pipeline” operating over long distances.
?1. How are tracheae different from tracheids? (Answer at the end of the article)
?2 . How do tracheids differ from fibers?
?3 . What do phloem and xylem have in common?
?4. How are sieve tubes different from tracheas?
Parenchyma cells of the xylem form peculiar rays connecting the pith with the bark. They conduct water in a radial direction and store nutrients. New xylem vessels develop from other parenchyma cells. Finally, wood fibers are similar to tracheids, but unlike it they have a very small internal lumen, therefore, they do not conduct water, but provide additional strength. They also have simple pores, not bordered ones.
Phloem (bast)- this is a living tissue that is part of the plant bark; a downward flow of water with assimilation products dissolved in it occurs through it. Phloem is formed by five types of structures: sieve tubes, companion cells, bast parenchyma, bast fibers and sclereids.
The basis of these structures are sieve tubes , formed as a result of the connection of a number of sieve cells. Their walls are thin, cellulose, the nuclei die off after ripening, and the cytoplasm is pressed against the walls, clearing the way for organic substances. The end walls of the cells of the sieve tubes gradually become covered with pores and begin to resemble a sieve - these are sieve plates. To ensure their vital functions, companion cells are located nearby, their cytoplasm is active, and their nuclei are large.
?5 . Why do you think that when sieve cells mature, their nuclei die off?
ANSWERS
?1. Tracheae are multicellular structures and do not have end walls, but tracheids are unicellular, have end walls and bordered pores.
?2 . Tracheids have bordered pores and a well-defined lumen, while fibers have a very small lumen and simple pores. They also differ in function, tracheids perform a transport role (conductive), and fibers perform a mechanical role.
?3. Phloem and xylem are both conductive tissues; their structures are tubular in shape and contain parenchyma cells and mechanical tissues.
?4. Sieve tubes consist of living cells, their walls are cellulose, they carry out the downward transport of organic substances, and the trachea are formed by dead cells; their walls are greatly thickened with lignin, they provide the upward transport of water and minerals.
?5. Downward transport occurs along the sieve cells and the nuclei, carried away by the flow of substances, would cover a significant part of the sieve field, which would lead to a decrease in the efficiency of the process.

Cork and crust in plants

Today we continue, interrupted for a while, the conversation about integumentary tissues.
CORK - This is a secondary integumentary tissue. It begins to mature at the end of the growing season and causes the color of the annual shoots to change from green to brown.
arises from the cells of the cork cambium Phellogen. In woody plants, cork forms on perennial shoots,
roots and bud scales, sometimes also on tubers and fruits.

in herbaceous dicotyledons it usually covers the roots and hypocotyl;

Among monocots, it is found in some palms (coconut), dracaenas, and agave;
phyllogene can also form during damage, and therefore a plug is formed here in the future.

Cork cells are dead due to the deposition of subberin in their walls, a process called suberization.
The shells become impermeable to liquids and gases, which leads to the death of the protoplast.
The cavities are filled with air and resinous substances, due to which the fabric acquires the ability to protect the plant from excessive evaporation,
temperature fluctuations, penetration of microorganisms, eating by animals.

The most powerful, annually growing cork oak can reach a thickness of 12 cm,
It is mainly used for hermetically sealing bottles of fine wine, juice, mineral water, as well as for the manufacture of linoleum, insulating boards, gaskets, floats, lifebuoys, etc.

Crust

Crust - this is dead tissue, which consists of layers of surface tissue of the trunk and branches, of various shapes and thicknesses,
separated from the rest of the mass, due to the formation between them and the latter of the so-called periderm - a special tissue arising from the cork cambium ( phellogen ).

It begins to form approximately in the third year of plant life (sometimes later).

The fact is that as a result of the activity of the cambium, the stem constantly increases in thickness,
and the inextensible wire can withstand the stress for some time, but there comes a moment when it cannot withstand it and bursts.
In the depths of the cortex, under the crack, phylogen is laid down, this leads to the formation of a new plug,

As soon as it matures, all overlying tissues also die, since the layers are separated by it from the internal tissues and cut off from the flow of nutrients.

Thus, the crust is a block of compressed, dry tissue, which is then shed by the plant.
Not all plants form a crust. In some, relatively rare cases, once formed phellogen remains functional for a long time.

On stems and roots, after the death of the cells of the integumentary tissues of primary origin, the functions of the integumentary tissue are performed by more complex formations, usually arising through corresponding changes in the tissues located after the primary integumentary tissues.

This newly formed tissue system is called periderm. Even through a superficial study, it is easy to detect a certain difference in the cover of the shoots of the first and subsequent growing seasons. First of all, the color of the integument becomes brown or dark; the surface of the above-ground shoots of most plants, when the periderm is formed, becomes covered with clearly visible tubercles, like warts, - lentils, and from some shoots the old covering tissue begins to peel off. In this case, periderm of the same type is formed on above-ground shoots and on roots; Even lentils form on the exposed roots.

The periderm consists of three tissues, following each other from the outer surface of the organ to its internal parts. The outer of these tissues is the integumentary tissue itself, called cork, or phellem, followed by a layer of secondary meristem - the cork cambium, or phellogen, and then the innermost tissue of the secondary integumentary tissue system - phelloderm. Phellema and phelloderm can be single- or multilayered, and phellogen is always single-layered.

The cork consists of tabular lashes arranged in strict radial rows; the membranes of its cells are suberized and tightly, without intercellular spaces, closed to each other. The cork cells are dead. The cork cambium is a series of thin-walled flat parenchyma cells filled with active protoplast. The cells of the cork cambium form both the cork itself and the phelloderm next inside it, which consists of completely vital cells, little distinguishable from the parenchyma of the organ’s cortex.

The cork cells in the adult state are either empty and filled with air, or contain a brownish mass; Phelloderm cells contain chloroplasts, accumulate starch, and generally have all the properties of a normal living parenchyma plant cell.

The periderm can arise in different layers of the cortex: the epidermis and subepidermal layer, as well as in various deeper layers of the cortical parenchyma and in the endoderm. After appropriate cytological rearrangement, the cells of the initial row, mostly along the entire circumference of the axial organ, divide periclinally. Of the two formed layers of cells, the inner one usually differentiates as phelloderm and does not divide further, and the outer one is again divided by tangential partitions. As a result of this second division of phellogen, a layer of phellem (outer) is formed, and the inner one continues to act as phellogen, dividing periclinally and laying down more and more new layers of cells. Often these layers are deposited only outwards, then differentiating as elements of a cork, while the inner zone of the periderm - phelloderm - remains single-layered.

Phellogen is sometimes divided anticlinal. Due to such divisions, the number of radial rows of periderm cells increases, which ensures the correct ratio of tissues in the axial organs growing in diameter.

All cells located outside the cork tissue die, since the cork isolates them from the water supply system and from the oxygen necessary for respiration. The formation of the periderm in cherries, for example, occurs in the epidermis, in currants - in the innermost layer of the primary cortex, therefore, in currants, after the formation of the periderm, the outer layers of the cortex die off and peel off. The cork cambium does not always lay out only those cells that quickly suberize. In some plants, for example, European euonymus, true cork cells alternate with rows of cells in which the shells are not suberized, but lignified. Such cells are called corky, and the fabric made up of them is pheloid. Phelloid tissue is rare and reaches different thicknesses in different plants. The presence of cork-like cells facilitates the exfoliation of the cork in separate pieces.

Many plants are characterized by the fact that on their axial organs, only one periderm is formed as a secondary integumentary tissue, i.e., a complex of tissues deposited by the once formed phellogen (gray alder, bird cherry, plane tree, eucalyptus, etc.). But there are also many plants in which the cork cambium dies off at a certain age of the axial organ and instead of it, a new cork cambium appears in the deeper layers of the bark. Then, after a certain period of activity, this layer of phellogen also dies off, and a new phellogen appears to replace it.

Since phellogen always deposits outward layers of cork cells, which cause the death of all tissues, solid masses of dead tissue often form on the surface of organs. Such a complex of various dead tissues, cut off by re-emerging layers of phellogen, is called crusty. Crust is formed in most temperate trees (oak, birch, pine, larch, etc.). Externally, the branches and trunks of trees that form the crust differ from the branches and trunks of trees covered only with periderm, where the cork cambium only suspends its activity during the cold periods of the year and does not periodically reappear. In trunks with a periderm that has only once begun to form, the surface is smooth over a large area from the top to the base of the trunk. Only at the very base of the trunk of very old trees do cracks appear in the bark. In plants that form a crust, cracks in the bark spread much higher.

So, in trees that form a crust, the periderm appears in the thickness of the bark several times, gradually cutting off deeper and deeper a number of anatomical elements of the bark. The latter die off and dry up along with the strips of cork tissue that isolate them from the internal living elements of the bark. If the new formation of the periderm does not extend along the entire circumference of the trunk or root, but only in places, then the crust is formed in irregular pieces. This crust is called scaly and occurs in most plants.

Develops much less frequently ring-shaped crust. Such a crust is created only if each newly emerging periderm, encircling the trunk in a ring, periodically cuts off cylindrical sections of the bark. A regular ring-shaped crust is formed in the grapevine, as well as in the bladderwort (Physocarpus).

Since the periderm contains phellogen, which is active only during the growing season and less active in winter, the plug deposited during different periods of the growing season decreases differently. As a result, annual layering of the cork tissue array occurs. However, well-defined layering of cork is rare.

Cork formation occurs not only in woody plants, but also in some herbaceous plants. Especially often, periderm in herbaceous plants occurs in the hypocotyledon, as well as on the roots. Sometimes on the subcotyledon, the epidermis, cut off from the bark by the resulting plug, peels off (garden quinoa is a common weed plant growing in the Caucasus). The cork is quite well expressed on the roots of some umbelliferous plants (carrots). The cork on potato tubers is well known. The formation of a plug occurs not only in dicotyledons and gymnosperms, but also in monocotyledons. In monocots capable of secondary thickening of the stem, even true periderm appears (dracaenas, yuccas).

Cork tissue also appears in places where there was injury. In such cases, the so-called wound plug, having the appearance of a real periderm. For example, after cutting pieces of tissue from cherry laurel leaves, the wounds heal within two weeks, and periderm forms on the exposed edges of the wounds. If you make an incision in the bark of a tree, then along the edges of the cut areas a periderm appears, spreading deeper and along the exposed surface of the wound.

The periderm develops when leaves fall in autumn, covering the remaining scars, as well as when flower shoots (for example, horse chestnut), fruits and branches (short shoots of plum, twigs of elm, poplar, hackberry, and in some years oak) fall off.

Under appropriate conditions, periderm can appear on almost all plant organs. It is formed not only in stems, roots, leaves, but also in fruits (Apples, pears). The thickness of the periderm varies from very thin films to masses of tissue of considerable thickness.

Cork tissue and, in general, the entire complex of periderm tissues protects the organ not only from excessive water loss, but also from various microorganisms, bacteria and fungi that destroy plant tissue. The mechanical protective role of cork is also quite possible. Not only does it completely replace the epidermis with its cuticle, but its protective properties are more pronounced.

Cork tissue is even more impermeable to gas and vapor exchange than the epidermis, therefore, to communicate internal tissues with the external air environment, there are special devices, somewhat similar in function to stomata, called lentils. Lentils appear differently depending on the depth of the periderm. In plants with a periderm that originates either in the epidermal cells or in the layers of the cortex closest to the epidermis (cherry, lilac), the lenticels are located under the stomata. Moreover, if there are few stomata on the shoot, then a lentil is formed under each of them; with a high density of stomata, lentils are formed only under some stomata. When stomata are arranged in close groups, lenticels can appear directly under such groups of stomata. The lenticels are laid either simultaneously with the beginning of the formation of the periderm, or slightly earlier, and then the formation of the periderm begins from the places where the lenticels are laid.

Lentils are part of the periderm. In different plants they occur at different periods of the shoot's existence, depending on the duration of the vital state of the epidermis. Often the beginning of the death of the epidermis serves as an incentive for the formation of the periderm; at the appropriate stage of development, the periderm causes isolation of the superficial tissues, which therefore die.

The formation of lentils begins with the fact that the cortex cells lying under the stomata divide, lose chlorophyll and turn into round, loosely connected cells, the protoplast of which dies soon after division. These cells form a characteristic cluster called performing lentil fabric. As the cells of the performing tissue accumulate, the underlying epidermis is torn, and these cells partially protrude outward. The new formation of performing cells occurs as a result of the activity of educational tissue directly associated with the phellogen of the periderm. In some plants, the performing tissue consists of cells so loosely connected to each other that they have the appearance of powder (cherry shoots, mulberry roots). These cells are protected from rash by a special covering fabric, also formed by phellogen. Like the supporting tissue, it is penetrated by intercellular spaces in the form of radial passages of this tissue. With a significant accumulation of executing cells, the layer of covering tissue breaks through, the executing cells spill out, and in place of the old covering tissue, a new layer of covering tissue appears from the educational layer of the lentil. Despite the presence of air-filled intercellular spaces, the cells of the covering tissue are connected to each other much more firmly than the cells of the filling tissue.

If the periderm is laid down in the deeper layers of the bark (currant, barberry), then no new formations occur under the stomata, and the lentils are laid down directly in the phellogen. When dead areas of bark fall off, the lenticels are exposed. In plants that form a thick crust that does not immediately fall off, but only cracks, lenticels develop in places exposed by cracks. In cases of crust formation, the lentils are formed again from new phellogen each time. In plants that do not form a crust, once the lentils are set, they can exist for several years. In the fall, the educational tissue of such a lentil can deposit a plug instead of producing cells, clogging the lentil. In spring, the supporting tissue develops again, tearing the cork film. The layer of covering fabric is similar to the layer of cork lentil fabric. The difference lies only in the degree of suberization of the cell membranes that make up these tissues.

Lentils are very common, but there are plants that do not have them: these are mainly vines, for example, grapevines. Aeration of the tissues of the shoots of these plants appears to be due to the fact that each year fresh areas of bark are exposed, which are more permeable to air than cork.

In conclusion, it should be added that lentil-like formations also form on fruits (wart-like spots on apples, plums, etc.).

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1What is the significance of the skin and the cork? 2Where is the phloem located and what cells does it consist of? 3What is cambium and where is it located? and got the best answer

Answer from Anastasia Popova[guru]
1) The skin and cork are classified as integumentary tissues. The main function is to protect the plant from mechanical damage, penetration of microorganisms, sudden temperature fluctuations, excessive evaporation, etc.
Epidermis (epidermis, skin) is the primary integumentary tissue located on the surface of leaves and young green shoots. It consists of a single layer of living, tightly packed cells that do not have chloroplasts. The cell membranes are usually tortuous, which ensures their strong closure. The outer surface of the cells of this tissue is often covered with a cuticle or waxy coating, which is an additional protective device. The epidermis of leaves and green stems contains stomata that regulate transpiration and gas exchange in the plant.
Periderm is the secondary integumentary tissue of stems and roots, replacing the epidermis in perennial (less often annual) plants. Its formation is associated with the activity of the secondary meristem - phellogen (cork cambium), the cells of which divide and differentiate in the centrifugal direction (outward) into the cork (phellema), and in the centripetal direction (inward) - into a layer of living parenchyma cells (phelloderm). Cork, phellogen and phelloderm make up the periderm.
The cells of the cork are impregnated with a fat-like substance - suberin - and do not allow water and air to pass through, so the contents of the cell die and it fills with air. The multilayer cork forms a kind of stem cover that reliably protects the plant from adverse environmental influences. For gas exchange and transpiration of living tissues lying under the plug, the latter has special formations - lentils; These are gaps in the plug filled with loosely arranged cells.
2) Bast is a conductive tissue. Another name is phloem. Phloem conducts organic substances synthesized in the leaves to all plant organs (downward current). It is a complex tissue and consists of sieve tubes with companion cells, parenchyma and mechanical tissue. Sieve tubes are formed by living cells located one above the other. Their transverse walls are pierced with small holes, forming a kind of sieve. The cells of the sieve tubes are devoid of nuclei, but contain cytoplasm in the central part, strands of which pass through through holes in the transverse partitions into neighboring cells. Sieve tubes, like vessels, stretch along the entire length of the plant. Companion cells are connected to the segments of the sieve tubes by numerous plasmodesmata and, apparently, perform some of the functions lost by the sieve tubes (enzyme synthesis, ATP formation).
3) Cambium is a secondary educational tissue. Located in the roots and stems of plants. Gives rise to secondary conducting tissues and ensures plant growth in thickness. Cambium also plays an important role in wound healing in plants. If the outer tissues of the stem are damaged, the cambium grows into the damaged area and differentiates into new xylem, phloem and cambium, each of these tissues continuing continuously with the corresponding tissue type in the undamaged part of the plant.

Answer from 3 answers[guru]

Hello! Here is a selection of topics with answers to your question: 1What is the significance of the skin and cork. 2Where is the phloem located and what cells does it consist of? 3What is cambium and where is it located?

When it comes to natural, eco-friendly building materials, one of the first materials that comes to mind is cork. Today it is used in different fields and for different purposes. Technical cork is used for heat and sound insulation of rooms, and also as a substrate for many floor coverings, for example, laminate. What are the features of this material, why is it so popular - we will tell you in this article, and also dwell on the technical characteristics and methods of using technical cork.

Features of cork materials and their advantages

Why are cork materials considered environmentally friendly? The fact is that the raw material for their production is the bark of a tree - the cork oak. And in the production of the final materials no synthetic substances are used; the material is obtained exclusively natural.

Cork oaks grow in Mediterranean countries, of which Portugal is considered the largest supplier of cork materials. When the cork oak tree reaches 25 years of age, the bark is removed from it for the first time. Thanks to natural intensive regeneration, the bark grows back and the tree does not die. After 9 years, you can remove the bark from the tree again, and with each removal, the quality of the bark becomes better and better.

After removal, the bark is dried naturally and then sent to a factory where various products are produced. To produce technical cork, the bark is crushed, and then the granules of the crushed bark are pressed under pressure and treated with steam. In this case, additional binders are not used, as is the case with artificial polymers, since the composition of the cork itself includes suberin - a natural glue, of which more than 45% is present in the material. The production technology of cork materials is called agglomeration, which is why technical cork positions are called black cork agglomerate and white cork agglomerate. They differ from each other only in that the bark of tree branches is used for the white agglomerate, and the bark of the trunk for the black agglomerate.

A unique feature of cork is its honeycomb structure. For every 1 cm3 of traffic jam there are up to 40 million cellular cells. Each cell has the shape of a polyhedron with 14 faces; the internal space of the polyhedron is filled with a gaseous mixture. It is thanks to this unique structure that cork materials have excellent thermal insulation properties and also do not allow water and gases to pass through. The cells are separated from each other by intercellular partitions.

Cork materials have both purely technical advantages over others and have other advantages that can play a decisive role when choosing an insulating material.

Advantages of technical plug:

• Completely environmentally friendly and hypoallergenic. Cork materials do not emit any harmful substances, either at rest or when heated or burned.
• Cork easily restores its shape after compression or torsion or bending. The material is extremely elastic. Even after years of use, it does not sag or get trampled, but continues to spring pleasantly underfoot.
• Cork is a natural antiseptic, so building materials made from it are not susceptible to rotting and the appearance of mold.
• Rodents and insects do not eat cork.
• Cork materials are not afraid of ultraviolet radiation and do not allow it to pass through.
• They do not become electrified and do not accumulate static electricity.
• When burned, cork materials do not emit phenols, chlorine, cyanide or other hazardous substances. To prevent the cork from burning, it is treated with a special substance, after which it can be classified as class G1 (non-flammable substances).
• Due to its natural unique structure, cork has low thermal conductivity, which makes it possible to use it for insulation or thermal insulation of buildings.
• Cork also has excellent soundproofing properties, reducing noise coming from the street.
• The material is easy to use, durable and versatile.
• Safe for the environment as it is disposed of naturally.
• Technical cork retains all its properties at subzero temperatures, which is why it is used in the production of refrigeration chambers.
• The water resistance of the cork allows you not to worry about the material even if the house is flooded.
• The following exceptional features can be distinguished: cork reduces the level of radioactive radiation, and also isolates it from the harmful effects of technopathogenic zones.

Also, cork materials are not afraid of alkalis and other substances.

Depending on the purpose for which it will be used, technical cork can be purchased in two forms: in rolls or in sheets. They differ not only in the release form, but also in the thickness of the material. Let's take a closer look at the characteristics and features of the use of rolled and sheet technical cork.

Technical roll cork is also called cork backing. Usually produced in rolls with a width of 1000 and 1400 mm, but the thickness of the material is more important. The thickness of cork in rolls can be 2 mm, 2.5 mm, 3 mm, 4 mm, 8 mm, 10 mm.

From the table above you can glean information about the technical characteristics of roll and sheet positions of technical cork.

To the above, we can add that the service life of the rolled substrate is equal to the service life of the building; it is one of the most durable natural materials.

Humidity material maximum 7%, which is extremely important during installation and further operation.

Permanent deformation 0.2%. Thanks to such low indicators, cork material does not wrinkle and returns to its previous shape after prolonged loads. For example, already 1.5 minutes after the cessation of exposure, the residual deformation is only 0.35%, after 15 minutes - already 0.25%, and after 150 minutes - only 0.17%.

Rolled cork is inert towards various chemicals.

pay attention to sound insulation coefficient. With a cork thickness of 2 mm it is 16 dB, and with a larger thickness (4 - 10 mm) the sound absorption coefficient can increase to 22 dB or more.

It is also important sonic boom resistance- 12 dB.

Deformation modulus of elasticity 2000 - 2500 kgf/cm2. This suggests that the material is able to withstand enormous loads without significant deformation and is not subject to destruction. Thanks to these properties, it can be used on many construction sites where the pressure of heavy equipment, for example, is very high.

Rolled technical cork is used as a heat-insulating and sound-proofing material. It fits under laminate, linoleum, parquet boards and panel parquet, serving as a substrate that reduces the transmission of clapping sounds from movement on a wooden floor. The underlay also serves as insulation between the base under the floor covering and the floor covering itself.

When installing heated floors, a rolled cork is also used and performs all the same functions.

An important advantage of using rolled cork when arranging floors is that the material allows you to level out minor unevenness in the base, and also has excellent shock-absorbing properties.

Rolled cork can also be used for insulation and soundproofing of walls and ceilings, but this is less convenient than using sheet technical cork. The fact is that the rolled cork must be straightened to secure it to the surface, and the sheets are already even. Rolled cork is an ideal option as a substrate for the floor, since it is pressed down by the floor covering. This is inconvenient when insulating walls and ceilings.

When laying rolled technical cork on the floor, the room temperature should not be lower than +10 ° C, the humidity should not be higher than 75%. Laying can begin a day after the roll is unpacked and the material is straightened. The floor screed must be level, clean and dry, the residual moisture should not exceed 2.5%. During the installation process, the roll is cut into the required lengths, which are laid on the floor surface without gaps. The joints are carefully taped. By the way, you cannot attach the rolled underlay to the floor mechanically, only by gluing it.

Technical cork in the form of sheets differs from rolled cork only in the strength of the material and size. Typically it consists of slabs 940x640 mm thick from 2 to 10 mm. The most common items are cork sheets with a thickness of 4, 6 and 10 mm. The price for sheet technical cork depends on the thickness of the material, because it also affects the technical properties.

The table of characteristics of sheet cork clearly shows that the so-called white agglomerate has greater sound absorption, which means it is more suitable for soundproofing rooms.

In addition, I would like to note that the material is easily restored after applying pressure. For example, when a load of 7 kg/cm2 is applied, the compression is 10%, and after an hour it is already 0.7%.

Sound absorption coefficient sheet cork measured at 2.1 kHz is 0.85. This allows for significant noise reduction and also completely eliminates reverberation. This is especially important when soundproofing recording studios and cinemas. After all, reverberation is the propagation of the sound of reflected sound - echo.

Application of technical sheet cork

Sheet technical cork is used for thermal insulation and sound insulation of premises. It insulates the floor, walls, ceilings, and ceilings. In a room that is isolated with technical cork, there is completely no echo and minimal noise from the street.

Technical cork can be found in any environment, so it can be used for finishing the external façade, for interior finishing of a room, and as a substrate for floor coverings and underfloor heating systems, just like rolled cork. As insulation, technical cork can be used in ceilings, on the floor, on walls, on the roof, and on external walls.

Important! The only limitation to the use of technical cork is in production facilities where metal is processed. The fact is that metal shavings quickly clog the pores of the cork, and it ceases to perform its functions.

In combination with other materials, technical cork significantly reduces noise and reverberation. Cork is also used to reduce vibrations coming from machine tools and other mechanisms, regardless of the load they place on the cork.

Cork provides the best sound absorption in the high frequency range above 1.5 kHz. This makes it possible to completely isolate the room from sudden loud sounds coming from the street, such as barking dogs or screaming. Also, when you soundproof the partitions between rooms, you can isolate the room so that you can’t hear the stereo system or TV.

But cork is not capable of reducing vibration noise that is transmitted through floors or vibration of mechanisms. Actually, like any sound insulation.

For the best sound insulation, the room is finished with cork in a comprehensive manner: ceiling + walls + floor. To improve the acoustic properties of the cork, it is advisable not to cover it with other finishing material. You can, for example, use cork decorative panels in addition to technical cork.

The technology for installing sheet technical cork is practically no different from installing a roll substrate. The only difference is that the sheet material can be laid immediately, since it is already flat. The sheets are glued to the surface with special glue, always end-to-end. Sometimes sheets are fastened mechanically, but much less frequently.

And finally, the advantages of sheet cork over rolled cork, which professional installers noticed:

• Leaf cork is denser.
• It is easier to install, since one person can handle it, unlike a roller, where an assistant is required.
• The sheet plug does not need to be leveled.
• It is more convenient to cut to the required size.
• The sheet cork does not break or crack, since it is not rolled up.

Technical cork is a universal material that is used in almost all places where insulation is needed: both indoors and outdoors. An undeniable advantage is water resistance and immunity to the influence of mold, rodents, and insects. The only drawback of technical cork is its high price compared to synthetic insulating materials of the same class.

The following main functions of plant stems can be mentioned:

movement of water and dissolved minerals from roots to leaves;

movement of organic substances from leaves to all other plant organs (roots, flowers, fruits, buds and shoots);

removal of leaves to sunlight and support function.

In connection with the functions they perform, the stems of higher plants, especially angiosperms, acquired their characteristic internal structure.

As you know, plants have woody and herbaceous stems. In terms of their internal structure, they differ from each other by the stronger development of some tissues and the underdevelopment of others. The clearest picture of the internal structure of the stem can be seen in the cross section of the tree.

The stem of a woody plant usually consists of four layers: bark, cambium, wood and pith. Moreover, each layer can include cells of different tissues. Thus, the bark contains peel, cork, bast fibers, sieve tubes and other tissues.

In young stems of woody plants, the surface remains skin. Like the skin of leaves, it has stomata through which gas exchange occurs. Under the skin or, if there is none, on the surface is cork. In a number of trees, the cork forms a fairly thick layer. There is a plug for gas exchange lentils, which are tubercles with holes. The cells of the skin and cork belong to the integumentary tissue. They protect the internal parts of the stem from damage, penetration of pathogens, and drying out.

Under the plug there may be a so-called primary cortex, and already under it is bast, which consists mainly of sieve tubes And bast fibers. Sieve tubes are bundles of living cells. Organic substances that were synthesized in the leaves during photosynthesis move along them. The cells of bast fibers have thick walls. Bast fibers are quite strong; they perform a mechanical support function.

Under the bark there is a thin layer cambium, which is an educational fabric. Its small cells actively divide during the growing season of the tree (from spring to autumn) and provide thickening of the stem. The resulting cambium cells, which are located closer to the cortex, differentiate into phloem cells. Those cambium cells that are closer to the wood become wood. Over the summer, more wood cells are formed than bast cells. On a tree cut, each year's wood cells are separated from each other by darker, smaller autumn wood cells. Thus, the growth rings are visible.

Under the cambium is wood, which usually makes up the bulk of the stem of a woody plant. Wood contains vessels. An aqueous solution moves along them from the roots. Vascular cells are dead. In addition to vessels, wood contains other types of tissues. So there are cells with thickened, strong walls.

core usually consists of loose storage tissue, consisting of large cells with thin walls.