The following properties are high adhesion to. What adhesion is. Adhesion of the main building materials

Why paint, applied to the painted surface after some time, is firmly held on it? Why is plastering when frozen grabbing with the base? Why is it possible to concrete in principle? The answer to these questions is one: the whole thing in adhesion is the phenomenon of the adhesion of two surfaces connected to each other.

What is adhesion

Adhesion determines the possibility of gluing solids using adhesive composition, as well as the strength of the connection of the decorative or protective coating with the basis. The reason for the adhesion of the adhesion relationship is the effect of molecular forces ( physical adhesion) or chemical interaction forces ( chemical adhesion).

The intensity of adhesion is determined by the pressure of the separation, which should be attached to the coating (plaster, paint, sealant, etc.) to tear / separate it from the base.

Thus, this indicator is made to measure in units of specific effort - megapascals (MPa). For example, the value of the bulk force (or sticking, that the same thing) in 1 MPa means that for separating the coating having an area of \u200b\u200b1 mm 2, an effort should be applied to 1 H (recall that 1 kg \u003d 9.8 H). Adhesive coating rates are their main characteristic, which provides the necessary strength, reliability, and also determines the complexity of working with them.

What affects the adhesive ability of substances used in construction

In the process of setting the working mixture, various processes occur in it, which determine certain changes in its properties. In particular, when shrink The mortar mixture is possible to reduce the contact surface with the appearance tensile stressesthat will lead to education shrinking cracks. As a result, the clutch of surfaces is weakened. For example, the adhesion of the old concrete surface with the new concrete does not exceed 0.9 ... 1.0 MPa, while the adhesion of dry building mixtures (which includes components, initiating chemical adhesion processes) with new concrete reaches 2 MPa and more.

How to improve adhesion

Typically implement a set of measures to improve adhesion: carry out mechanical (grinding), physico-chemical (shtclovation, primer) and chemical (elastification) processing of the base surface. The specified processes in repair and construction work are particularly effective when contacting surfaces are heterogeneous not only in its chemical service, but also under the conditions of their formation.

Important! Fresh alkaline cement solution is always poorly connected with the surface of the old concrete, so when working with old concrete, multilayer adhesive compositions should be used.

How to measure the adhesion ability of materials

GOST 31356-2007 regulates the determining the strength of the adhesion of dry construction mixtures with the base. On the sequence of test tests of materials on their adhesion. The technology of conducting such tests allows you to determine the adhesion strength of such coatings, such as ceramic tiles, various protective coatings, plaster, etc. Based.

To control the quality of work performed, it is convenient to use the onyx-up adhesimetre system. The measurement range of the grasp effort using this instrument is 0 ... 10 kN. When testing, an effort is measured, which is necessary for separating or separating the coating from the surface of the base in the direction perpendicular to the coating plane. The convenience of applying the adhesiveter is that it is possible to operately control the quality of finishing and plastering. The device is compact and convenient to maintain (see Fig. 1.2.3).

Fig.1. Determination of the grasp of ceramic tiles with an adhesiometer (step 1)

Adhesion (from Lat. Adhasio - adhesion) in physics - the adhesion of the surfaces of heterogeneous solid and / or liquid bodies. Adhesion is due to intermolecular interactions (van der Wales, polar, sometimes mutual diffusion) in the surface layer and is characterized by the specific work required for the separation of surfaces. In some cases, adhesion may turn out to be stronger than cohesion, that is, the adhesion inside a homogeneous material, in such cases, when applying a tearing force, a cohesive gap occurs, that is, the gap in the volume is less durable of contacting materials.
Adhesion significantly affects the nature of the friction of contacting surfaces: so, when the surface interacts with low adhesion, friction is minimal. As an example, polytetrafluoroethylene (Teflon) can be brought, which, by virtue of the low adhesion, in combination with most materials has a low friction coefficient. Some substances with a layered crystal lattice (graphite, molybdenum disulfide), characterized simultaneously low adhesion and cohesion values, are used as solid lubricants.
The most famous adhesion effects are capillary, wettability / non-inspireness, surface tension, menisy of fluid in a narrow capillary, friction of two absolutely smooth surfaces. In some cases, adhesion criterion in some cases can be the time of separation of the layer of material of a certain size from another material in the laminar fluid flow.
Adhesion takes place in the processes of gluing, soldering, welding, coating. The adhesion of the matrix and filler of composites (composite materials) is also one of the most important factors affecting their strength.
In biology, cell adhesion is not just a cell connection between themselves, and such a compound, which leads to the formation of certain proper types of histological structures specific to data types of cells. The specificity of cell adhesion is determined by the presence of cell adhesion proteins on the surface of cells - integrins, cadgers, etc. For example, platelet adhesion on the baseal membrane and on collagen fibers of the damaged vascular wall.
In the anti-corrosion protection of the adhesion of the paint and varnish material to the surface, the most important parameter affecting the durability of the coating. Adhesion is the adhesion of paint and varnish material to the surface of the surface, one of the main characteristics of industrial LKM. The adhesion of paints and varnishes may have a mechanical, chemical or electromagnetic nature and is measured by the power of the parallery coating per unit area of \u200b\u200bthe substrate. The good adhesion of the paint and varnish material to the stained surface can be ensured only with a thorough cleaning of the surface from dirt, fat, rust and other contaminants. Also, to ensure adhesion, it is necessary to achieve a given coating thickness, which is used for the thickness gauge of the wet layer. To assess adhesion / cohesion, criteria were adopted and approved.

ADHESION

(from Lat. Adhasio -), the occurrence of communication between the surface layers of two heterogeneous (solid or liquid) bodies (phases) listed in contact. It is the result of intermolecular interaction, ionic or metal. connections. Private case A.- - Viction of contacting identical bodies. Labor case A.- Chem. Viction on the surface of the section (hemosorption) with the formation of the Him layer. Connections. A. Measured by force or work of separation to units. The surface of the surfaces of the surfaces (adhesive seam) and it becomes extremely large with full contact over the entire area of \u200b\u200bcontact bodies (for example, when applying liquid (lacquer, glue) on TV. Body in conditions of complete wetting; forming one body as a new phase of another; formation of electroplating etc.).

In process A. The free body decreases. Reducing this energy, which is included in 1 cm2 of adhesion seam, called. The free energy of A. FA, K-paradium is equal to the work of the WA adhesion separation (with a reverse sign) in reversible isothermich. Process and expressed through tension at the borders of the section The first body - external. Wednesday (in K-Roy are Body) S10, Second Body - Wednesday S20, First Body - Second Body S12:

Fa \u003d Wa \u003d S12-S10-S20.

With full wetting q \u003d 0 and w \u003d 2s10.

The combination of methods for measuring the force of separation or rocking with A. Naz. A d g E. and about m. A. may be accompanied by mutual diffusion in B, which leads to the blurring of the adhesion seam.

Physical encyclopedic dictionary. - M.: Soviet Encyclopedia. . 1983 .

ADHESION

(from Lat. Adhasio - sticking, grip, attraction) - the connection between heterogeneous condensed bodies when they are configured. A special case of A.- authezia, manifested in contact with homogeneous bodies. With A. and autohezia, the border of the phase partition between bodies is maintained, unlike cohesion Determining the connection within the body within the same phase. Naib The value has A. to a solid surface (substrate). Depending on the properties of the adhesive (adhesive body), A. liquid and solid bodies (particles, films and structured elase-cycle plastic are distinguished. Mass, eg melt, bitumen). Outgeezia is characteristic of solid films in multilayer coatings and particles, determines dispersed systems and compositions. Materials (powders, soil, concrete, etc.).

A. Depends on the nature of the contacting bodies, the SV-in their surfaces and the area of \u200b\u200bcontact. A. is determined by the forces of intermolecular attraction and increases, if one or both of the body is electrically charged if the donor-acceptor bond is formed during contact, as well as the capillary condensation of vapors (for example, water) on the surfaces, as a result of the occurrence of Him. Communication between adhesive and substrate. In the process of diffusion, the mutual penetration of the molecules of contacting bodies are possible, erosion of the border of the phase separation and transition A. in cohesion. A. Major may change when Adsorption At the border of the phase partition, as well as due to the mobility of the polymer chains between solid bodies, a thin layer of fluid is formed in a liquid medium and arises that prevents A. consequence A. Fluid to the surface of a solid body is wetting.

The possibility of A. for isothermich. The reversible process is determined by the loss of free surface energy, K-paradium is equal to the equilibrium operation of adhesion:

where - the surface tension of the substrate 1 and adhesive 2 at the border with the environment 3 (eg, air) to A. and with A. with an increase in the surface tension of the substrate A. Grows (for example, a large for metals and small polymers). The above urination is the initial to calculate the equilibrium operation of A. liquid. A. solid bodies are measured by an external value. Effects with the separation of adhesive, A. and the authezia of particles - moderate force (calculated as Mat. Waiting), and powder - UD. force. Forces A. and authezia particles increase friction when moving powders.

When separating the films and structurr. The masses are measured by adhesive strength, K-paradium, except A., includes an effort to deformation and the course of the sample, the discharge of the double electric. layer and other phenomena. Adhesion strength depends on the size (thickness, width) of the sample, directions and the speed of the application external. efforts. With A., weak compared to cohesion, there is an adhesive gap, with relatively weak cohesion - the cohesion gap of the adhesive. A. Polymer, paintwork, etc. The film is determined by wetting, the condition for the formation of the contact area with liquid adhesive and when it is solidified by an injection. Stresses and re-laxac. processes, influence external. Conditions (pressure, tempo, electric fields, etc.), and the strength of adhesive compounds is also a cohesion of the hardened adhesive layer.

Change A. Due to the occurrence of double electric. The layer in the contact zone and the formation of donor-no-acceptor communication for metals and crystals is determined by states external. electrons of surface layer atoms and crystal defects. Grills, semiconductors - surface states and the presence of impurity atoms, and dielectrics - dipole moment of functional groups of molecules at the border of the phases. The area of \u200b\u200bcontact (and the value of A.) solid bodies depends on their elasticity and plasticity. Strengthen A. can be activated, i.e., changes in morphology and energy. Surface Meache. Cleaning, cleaning with solutions, vacuuming, exposure to EL.-Magn. radiation, ion bombardment, as well as the introduction of Split. Functional groups. So. A. Metalch. The film is achieved by electrodeposition, metal. And Nemoy Tallich. Flock - Termich. Evaporation and vacuum spraying, refractory films - with a plasma jet.

A combination of methods for determining A. Naz. adhesiometry, and their instruments implementing adhesiometers. A. can be measured by direct (effort in violation of adhesive contact), non-destructive (by changing the parameters of ultrasonic and e-magnes. Waves due to absorption, reflection or refraction) and indirect (characterizing A. in comparable conditions only relative, for example. Having flaking the films after the end, the slope of the surface for powders and others) methods.

LIT: 3Imon A. D., adhesion dust and powders, 2 ed., M., 1976; His adhesion of films and coatings, M., 1977; His adhesion, M., 1983; Dryagin B. V., Krotova N. A., Smilga V. P., Adhesion of solid bodies, M., 1973; 3Imon A. D., Andrianov E. I., Outgestion of bulk materials, M., 1978; Basin V. E., adhesion strength, M., 1981; Coagulation contacts in dispersed systems, M., 1982; Vakula V. L., Podtykin L. M., Physical chemistry of adhesion of polymers, M., 1984. A. D. Zimon.

Physical encyclopedia. In 5 volumes. - M.: Soviet Encyclopedia. Editor-in-Chief A. M. Prokhorov. 1988 .

Synonyms:

Watch what is "adhesion" in other dictionaries:

- (from lat. Adhasio sticking) in physics clutch surfaces of heterogeneous solid and / or liquid tel. Adhesion is due to intermolecular interaction (Vanderwals, polar, sometimes by the formation of chemical connections or ... ... Wikipedia

adhesion - clutch strength The totality of forces connecting the coating with the surface in the surface. [GOST R 52804 2007] adhesion Surface phenomenon, leading to the adhesion between the solumed materials presented in contact with heterogeneous materials under the action of physico ... ... Technical translator directory

Adhesion - - the grip of the surfaces of heterogeneous bodies. It is achieved when applying electroplated and paint coatings, gluing, welding, etc., as well as in the formation of surface films (for example, oxide, sulphide). When the interaction of the molecules of one ... Encyclopedia Terms, Definitions and Explanations of Building Materials

- (Lat. Adhasio, from Adharere adhere, be connected). Adhesion, clutch. A dictionary of foreign words included in the Russian language. Chudinov A.N., 1910. LAT adhesion. Adhasio, from Adharere, adhere. Cunning. Explanation of 25,000 foreign ... Dictionary of foreign words of the Russian language

Adhesive, gluing, sticking, gluing, grip dictionary of Russian synonyms. The adhesion is SUB., Number of synonyms: 5 Printing (12) ... Synonym dictionary

adhesion - And, g. Adhésion f., it. Adhäsion Lat. Adhasio adhesion. 1372. Lexis. Adhesive surfaces of two heterogeneous solid or liquid tel. SIS 1985. The bonding phenomenon was known for a long time, but began to think about his nature relatively recently ... ... Historical Dictionary of Gallicalism Russian Language

- (from Lat. Adhasio sticking) The grip of the surfaces of heterogeneous bodies. Thanks to adhesion, applying electroplated and paint coatings, gluing, welding, etc., as well as the formation of surface films (eg, oxide) ... Big Encyclopedic Dictionary

Adhesion, attraction of molecules of one substance to other molecules. In rubber, glue and pastes, the adhesion property for holding together various substances. See also Cugezzia ... Scientific and Technical Encyclopedic Dictionary

There are many different ways of interaction between physical bodies. One of them is the adhesion of the surface. Let's look at what this phenomenon and what it has properties.

What is adhesion

The definition of the term becomes more understandable if you find out how this word was formed. With Latin Adhasio translates as "attraction, adhesion, sticking". Thus, adhesion is nothing but the relationship of condensed heterogeneous bodies, which occurs when they are contacting. When homogeneous surfaces come into contact, a special case of this interaction occurs. It is called authezia. In both cases, you can make a clear line of the phase partition between these objects. In contrast, it is released by cohesion at which molecules inside the substance itself occurs. To be clearer, consider an example from life. Take conventional water. Then we will apply them to different parts of the same glass surface. In our example, water is a substance that is inherent poor adhesion. It is easy to check, turning the glass upside down. Cugezzia characterizes the strength of the substance. If you glue two pieces of glass with glue, the connection will be quite reliable, but if you combine them with plasticine, the latter breaks up in the middle. From which it can be concluded that its cohesion for durable communication will not be enough. We can say that both these forces complement each other.

Types of adhesion and factors affecting its strength

Depending on which bodies interact with each other, certain features of adhesion are manifested. The greatest value is adhesion arising when interacting with a solid surface. This property has a practical value in the manufacture of all sorts of adhesives. In addition, the adhesion of solids and liquid is also distinguished. You can select multiple key factors that directly determine the strength with which adhesion will appear. This is the area of \u200b\u200bcontact, the nature of contacting bodies and the properties of their surfaces. In addition, if at least one of the pair of objects carrying on itself, the donor-acceptor connection will appear when interacting, which will strengthen the clutch force. A significant role is played by the capillary condensation of water vapor on the surfaces. Due to this phenomenon between the substrate and adhesive, chemical reactions may occur, which also increases the power strength. And if the solid is dipped into the liquid, then you can see the consequence, which also causes adhesion, is wetting. This phenomenon is often used in coloring, gluing, soldering, lubrication, enrichment of rocks, etc. To eliminate adhesion, a lubricant is used, which prevents the direct contact of the surfaces, and for its amplification, on the contrary, the surface is activated by means of mechanical or chemical purification, the effects of electromagnetic radiation or the addition of various functional impurities.

Quantifying the degree of such interaction is determined by the effort to be applied to divide the contacting surfaces. And in order to measure the effect of adhesion, special devices are used, which are called adhesiometers. The same combination of methods for its definition is called adhesiometry.

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This clutch of various in its composition and structure of materials, due to their physical and chemical properties. The term adhesion occurred from the Latin word ADHESION - adhesion. In construction, they give a more narrow-controlled and specific designation of what adhesion is the ability of decorative and finishing coatings (LKM, plaster), sealing or adhesive mixtures to a solid and reliable compound with the outer surface of the base material.

Impressive demonstration of the effect of adhesion of modern adhesive compositions

Important! The concepts of adhesion and cohesion should be distinguished. Adhesion connects differentty materials, affecting only the surface layer. For example, paint on a metal surface. Cugezzia is a compound of the same type of materials, as a result of which intermolecular interactions are formed.

Adhesion is one of the key properties of materials in the following areas:

Metallurgy - anti-corrosion coatings.
Mechanics - Lubrication layer on the surface of machine elements and mechanisms.
Medicine - dentistry.
Building. In this industry, adhesion is one of the main indicators of the quality of work and reliability of structures.

Almost all stages of construction are controlled by adhesion indicators for the following compounds:

paints and varnishes;
plaster mixes, screed and fill;
adhesive compositions, masonry solutions, sealants, etc.

An example of chemical adhesion - the reaction of the compound of silicone sealant with glass

There are three basic principles of the adhesive connection of materials. In construction and technology, they are manifested as follows:

Mechanical - The grip occurs by sticking the material applied to the base. The mechanism of such a compound is to penetrate the applied substance in the pores of the outer layer or compound with the rough surface. An example is the color of the surface of concrete or metal.
Chemical - Communication between materials, including different density, occurs at the atomic level. To form such a connection it is necessary for the presence of a catalyst. An example of adhesion of this type is a soldering or welding.
Physical - Electromagnetic intermolecular communication occurs on mating surfaces. It may be formed as a result of a static charge or under the influence of a permanent magnetic or electromagnetic field. An example of using technology - staining of various surfaces in an electromagnetic field.

Adhesion properties of construction and finishing materials

The adhesion of construction and finishing materials is carried out mainly, according to the principle of mechanical and chemical compound. The construction uses a large number of different substances, performance characteristics and specific interaction of which differ radically. We divide them into three main groups and characterize in more detail.

paints and varnishes

The adhesion of the LKM to the surface of the base is carried out by a mechanical principle. At the same time, the maximum strength indicators are achieved if the work surface of the material has roughness or porous. In the first case, the area of \u200b\u200bcontact is significantly increasing, in the second, the paint penetrates into the surface layer of the base. In addition, the adhesive properties of the LKM increase due to various modifying additives:

organosilanes and polyorganosyloxanes have an additional hydrophobic and anti-corrosion action;
polyamide and polyester resins;
metallo-organic catalysts of chemical processes of disconcing LKM;
ballast fine fillers (for example, talc).

Talc filler paint - non-pesticating flame retardant

Construction plaster and dry adhesive mixtures

Until recently, construction and finishing works were conducted using various solutions based on plaster, cement and lime. Often, they were mixed in a certain proportion, which gave a limited change in their main properties. Modern ready-made dry construction mixes: starting, finishing and multifinic plasters and putty, have a much more complex composition. Additives of various origins are widely used:

mineral - Magnesia catalysts, liquid glass, clamping, acid-resistant or non-shrinkable cement, microsinking, etc.
polymer - dispersible polymers (PVA, polyacrylates, vinyl acetates, etc.).

Such modifiers significantly change the following main characteristics of building mixtures:

plastic;
water-retaining properties;
thixotropy.

Important! The use of polymer modifiers gives a more pronounced effect of adhesion enhancement. However, the formation of stable compounds of polymer films on the boundary of different type materials (base - hardening plaster) is possible only at a certain temperature. This term is called the minimum fleet of film formation - MTP. In different plasters, it can be different from + 5 ° C to + 10 ° C. To avoid bundle, it is necessary to accurately adhere to the manufacturer's recommendations relative to the temperature, both the environment and the grounds.

Sealants

Sealants used in construction distinguish three different types, each of which requires certain conditions for high-strength adhesion with the base material. Consider each type of Read more.

Drying sealants. The composition includes various polymers and organic solvents: styrene butadiene or nitrile, chloroprene rubber, etc. As a rule, there are a pasty consistency with a viscosity of 300-550 Pa. Depending on the viscosity, they are applied either with a spatula or brush. After applying them to the surface, a certain time is necessary for drying (evaporation of the solvent) and the formation of a polymer film.

Sleep sealants. It is usually from rubber, bitumen and various plasticizers. Have limited resistance to high temperature, not more than 70 0 C-80 0 s, after which they begin to deform.

Cutting sealants. After applying them, under the influence of various factors: moisture, heat, chemical reagents, there is an irreversible polymerization reaction.

Of all these varieties, curable sealants provide maximum clutch reliability with the micronether base of the base. In addition, they are resistant to high temperatures, mechanical and chemical influences. They have an optimal combination of rigidity and viscosity, allowing to maintain an initial form. However, are the most expensive and complex in use.

How is adhesion measured?

Adhesion measurement technology, test methods, as well as all indicators of the strength of the compound of the materials are indicated in the following standards:

GOST 31356-2013 - Plots and plasters;
GOST 31149-2014 - Paintwork materials;
GOST 27325 - LKM to wood, etc.

Information! Adhesion is measured in kgf / cm 2, MPa (megapascular) or KN (kilonutytons) is an indicator of force that must be applied to separate the materials of the base and coating.

If earlier the adhesive characteristics of the materials could be measured only in laboratory conditions, then at the moment there are many devices that can be used directly at the construction site. Most of the methods for measuring adhesion, both "field" and laboratory associated with the destruction of the external covering, layer. But there are several devices, the principle of which is based on ultrasound.

Knife adhesimetre. Used to determine the adhesion parameters by the method of lattice and or parallel cuts. It is used for paint and varnish coatings with a thickness of up to 200 microns.

Pulsar 21. The device determines the density of materials. It is used to detect cracks and bundles in concrete both pieces and monolithic. There are special firmware and subprogrammes that in the density of adjustment, allow to determine the strength of the adhesion of the plastecrops of various types to concrete surfaces.

CM-1U. Used to determine the adhesion of polymer and bitumen insulating coatings by the method of partial destruction - shift. The measurement principle is based on the identification of linear deformations of the insulating material. As a rule, it is used to determine the strength of the insulating coating of pipelines. Use to test the quality of bituminous waterproofing to build structures: walls of basements and basement floors, flat roofs, etc.

Factors that reduce the adhesion of materials

Various physical and chemical factors affect the reduction of adhesion. Physical is the temperature and humidity of the environment at the time of applying decorative and finishing or protective materials. Also reduced adhesion interactions of various contaminants, in particular, the dust covering the base surface. In the process of operation, the effect on the strength of the combination of paints and varnishes may have ultraviolet radiation.

Chemical factors that reduce adhesion are represented by various material pollutants surface: gasoline and oil, fats, acidic and alkaline solutions, etc.

Also adhesion finishing materials can reduce various processes arising in building structures:

shrinkage;
stretching and compressive stresses.

Information! The substance applied to the surface to increase the clutch force between the base and finishing material is called adhesive. The basis for which adhesive is applied is called a substrate.

Methods of increasing adhesion

In construction, there are several universal ways to increase adhesion of decorative finishing materials with a base surface:

Mechanical - The surface of the base gives roughness to increase the area of \u200b\u200bcontact. To do this, it is treated with various abrasive materials, applied notches, etc.
Chemical - The composition of the applied protective finishing materials add various substances. This is, as a rule, polymers forming more durable bonds and give material additional elasticity.
Physical and chemical - The base surface is treated with primer changing the main chemical parameters of the material and affects certain physical properties. For example, a decrease in moisture absorption in porous materials, fixing the loose outer layer, and the like.

Ways to increase adhesion to various materials

Let us last in more detail on the methods of improving adhesion for various materials used in construction.

Concrete

Concrete building materials and structures are used everywhere in construction. Due to the high density and smoothness of the surface, their potential adhesion indicators are rather low. To increase the strength of the decoration compounds, the following parameters must be taken into account:

dry or wet surface. As a rule, adhesion to the dry surface is higher. However, many adhesive mixtures have been developed that require pre-wetting the surface of the base. In this case, you must pay attention to the requirements of the manufacturer;
ambient temperature and base. Most of the finishing materials are applied to concrete surfaces at an air temperature of at least + 5 ° C ... + 7 ° C. At the same time, the concrete should not be frozen;
primer. Used in mandatory. For dense concrete, these are compounds with quartz sand fillers (Betonontact), for porous concrete (foam, aerated concrete), these are primer in deep penetration based on acrylic dispersions;
adding modifiers. Ready dry plaster mixes already have various adhesive additives. If the plaster is mixed alone, it is recommended to add: PVA, acrylic primer, instead of the same amount of water, silicate adhesive, which gives the finishing material additional water-repellent properties.

Metal

A key role in the strength of the combination of paint materials with a metal surface is played by the method and quality of surface preparation. At home, it is recommended to perform the following steps:

degreasing - Metal processing by various solvents: 650, 646, P-4, White spirit, acetone, kerosene. In extreme cases, the surface is cleaned with gasoline;
matting - the processing of the base with abrasive materials;
padding - The use of special paints of primers. They are implemented complete with decorative LCMs of a definite type.

Important! Lead adhesion, aluminum and zinc is much lower than that of cast iron and steel. The reason is that these metals form oxide films on their surface. Therefore, peeling of paint coatings occurs through the oxide layer. Staining these materials is recommended immediately after removing the film with a mechanical or chemical method.

Wood and wood composites

Wood is a porous surface with a lot of irregularities and does not experience special problems with the strength of the compound of finishing materials. But there is no limit to excellence, therefore various technologies have been developed to improve adhesion in combination with the preservation of the protective and decorative properties of the finishing itself. Their use, for example, in combination with acrylic paints, significantly improves weather resistance, resistance to ultraviolet fading, gives biological protection material. The wood surface is treated with a variety of primers, most often, based on borazate compounds and nitrocellulose.

Adhesion when welding

Welding is one of the most durable methods for connecting metal structures. This grip of the molecules of two elements without the use of intermediate or auxiliary substances - glue or solder. This process occurs under the influence of thermal activation. The outer layer of the combined elements is heated above the melting point, after which the intermolecular convergence occurs and the connection of the materials.

The following factors can serve as an obstacle to high-quality adhesion during welding:

the presence of oxide films. They are removed mechanically or chemically during the preparation of the surface or disappear directly during the welding process under the influence of high temperature or fluxes;
missing the chemical composition of materials and electrodes. Special attention should be paid to the presence and amount of silicon and carbon in the details connected. To connect steels of different brands, it is recommended to use electrodes with a low content of diffusion hydrogen;
insufficient propulsion depth, which directly depends on the current strength and speed of the electrode.