RU2725381C1 - Fiberglass for applying protective fiberglass coating on pipe, method of applying protective glass fibre coating, device for applying protective glass fibre coating and pipe with protective glass fibre coating - Google Patents

Abstract

FIELD: chemistry.SUBSTANCE: invention relates to production of pipes with protective fiberglass coating, glass tape for coating of pipe, method of applying glass tape on steel pipe and device for application of glass tape on steel pipe. Pipe contains a coating from glass tape containing a cloth from glass winding impregnated with polymer melt; at that, the web is formed unwinding glass winding from bobbins and pulling glass-spinning through a system of shafts, which swirl threads at bending, the formed web is impregnated with polymer melt at melt temperature from 100 °C to 250 °C, as used polyethylene melt containing component A in the form of homo- and/or ethylene copolymer with density of 0.910–0.960 g/cm, component B in the form of homo- and/or copolymer of propylene with density of 0.860–0.920 g/cmand a stabilizer selected from: pentaerythrol tetrakis-3-(3,5-ditertbutyl-4-hydroxyphenyl)propionate, 2,6-di-tert-butyl-para-cresol, tris(2,4-di-tert-butylphenyl)phosphite, dysteryl thiodipropionate with the following content of components: component A from 49.2 % to 89.9 %, component B from 10 % to 50 %, stabilizer from 0.1 % to 0.8 %.EFFECT: invention provides lower rigidity of pipe for bending, reliable protection of pipe against mechanical damages during installation and operation of pipeline and longer service life of constructed pipeline.8 cl, 3 dwg, 1 tbl

Description

The invention relates to the production of pipes, namely the production of pipes with an external coating designed to protect the anticorrosive coating of pipelines from mechanical damage during pipeline construction by pulling in land, underground or underwater passages, sea shelves, in flooded or marshy areas and in the extreme North , as well as during reconstruction, repair and during operation.

It is known that when pulling a pipeline equipped with an anticorrosive coating, an important factor is the stability of the anticorrosive coating from damage due to exposure to stones, rocky soil, etc. This is especially true for the construction of pipelines in mountainous areas and in difficult soil conditions, the construction of underwater crossings, in permafrost soils, on sections of pipelines equipped with ballasting and fixing means without using lining means, as well as the construction of crossings under railways and roads.

Damage to the anti-corrosion coating as a result of such effects leads to rapid corrosion of the steel conductive pipe, the need for repair or replacement, which leads to significant material costs.

To prevent damage to the anticorrosive coating of the conductive pipe, various protective coatings are applied that are applied to the anticorrosive coating of the conductive pipes. So, it is possible to apply a concrete coating to the anticorrosive coating of a conductive pipe. For example, this is described in RF patent No. 93485, prior. 11.11.2009, publ. 04/27/2010. According to a utility model, a ballast-coated pipe consists of a central pipe and a ballast material. Moreover, inside the ballast material is a mesh or reinforcing cage with clamps that hold the mesh or reinforcing cage on the central pipe. At the same time, the reinforcing cage has at least four longitudinal reinforcement, onto which the transverse reinforcement is wound in a spiral with equal pitch. The connection of the longitudinal and transverse reinforcement is carried out using a knitting wire and / or welding. As ballast material, concrete was used, with a mobility of 10 to 14 cm along the Abrams KA Cone, which was applied by spraying followed by rolling rollers. The pipe resulting from the use of the proposed utility model is well protected from damage to the anti-corrosion coating layer during construction by pulling the pipeline. The main disadvantage of the utility model is the heavy weight, which entails difficulties in delivering pipes to the construction site.

You can get rid of this drawback, namely, heavy weight, using a light material, such as polymer, as a protective coating.

So, for example, in RF patent No. 50278, prior. 06.06.2005, publ. December 27, 2005, selected as a prototype, a utility model is described in which an insulating tape is used to protect the outer surface of the pipeline. It includes a polymer base film, a mastic layer, in the thickness of which a reinforcing material is placed, and a release layer. As a reinforcing material proposed, for example, fiberglass mesh. In this case, a film of polyethylene or a copolymer of ethylene with vinyl acetate, electronically chemically modified and uniaxially oriented, is used as the base polymer film. The main disadvantage of the proposed utility model is its low resistance to longitudinal slots, which arise as a result of the interaction of the applied protective insulating tape with the sharp edges of stones, rocky soil, ice in permafrost soils, etc. when pulling the pipeline during the construction process. Also, when pulling the hook of a reinforcing fiberglass mesh over a protrusion of, for example, stone or rocky soil, it leads to a shift or rush, which, in due time, leads to exposure or removal of the anti-corrosion coating.

The technical task is to create a pipe with a protective coating that can withstand any impact of sharp edges of stones, rocky soil, ice in permafrost soils when dragging the pipeline during construction. Also, a fiberglass coated pipe has less bending stiffness than a concrete coated pipe. That allows you to go through underground passages with pulling the pipeline with a large bend radius of the pipe whip, and accordingly reduce the length of this transition.

The technical result achieved by the present invention is to increase the service life of the constructed pipeline.

The problem is solved, and the technical result is achieved in that the glass tape includes a glass roving impregnated with a polymer melt. In this case, the web is formed by unwinding the glass roving from the spools and dragging the glass roving through a system of shafts that fluff the threads during bending. The formed web is impregnated with a polymer melt at a melt temperature of 100-250 ° C. As the melt, polyethylene is used containing component A in the form of a homo- and / or ethylene copolymer with a density of 0.910-0.960 g / cm ³ , component B in the form of a homo- and / or copolymer of propylene with a density of 0.860-0.920 g / cm ³ and a stabilizer selected from the series: pentaerythrol tetrakis-3- (3,5-ditretbutyl-4-hydroxyphenyl) propionate, 2,6-di-tert-butyl-para-cresol, tris (2,4-di-tert-butylphenyl) phosphite , disteryl thiodipropionate, in the following ratio of components:

component a from 49.2% to 89.9% component b from 10% to 50% stabilizer from 0.1% to 0.8%.

The problem is also solved, and the technical result is achieved by applying a protective fiberglass coating to the steel pipe by a method in which the steel pipe is installed on the drive rollers of the winding machine, and, rotating the pipe, wind a glass tape on it. When winding before the glass tape enters the pipe, the glass tape and the pipe are heated with at least one hair dryer to a temperature of at least 160 ° C, while the glass tape tension during winding should be in the range from 380 to 820 N.

It is preferable that when winding before the glass tape enters the pipe, the glass tape is heated with a hairdryer to a temperature of at least 160 ° C, and the pipe is heated with a second hairdryer to a temperature of at least 160 ° C.

The problem is also solved, and the technical result is achieved by the fact that the device for applying a protective fiberglass coating on a steel pipe consists of a winding machine with drive rollers for installing a steel pipe and a forming path with tensioners for installing a reel with fiberglass tape. At the same time, at least one hair dryer for heating the glass tape and the surface of the steel pipe is installed in the zone of entry of the glass tape onto the pipe.

Preferably, two hair dryers are installed, one hair dryer for heating the glass tape and a second hair dryer for heating the surface of the steel pipe.

In the particular case, it is desirable to make the nozzle of the first and second hairdryer in the form of a flat socket.

In the particular case, the nozzle of the first hairdryer is preferably made in the form of a tunnel nozzle, and the second hairdryer in the form of a flat socket.

The problem is also solved, and the technical result is achieved by the fact that the pipe with a protective fiberglass coating is provided with a coating of glass tape, including a glass roving impregnated with a polymer melt. In this case, the web is formed by unwinding the glass roving from the spools and dragging the glass roving through a system of shafts that fluff the threads during bending. The formed web is impregnated with a polymer melt at a melt temperature of 100 to 250 ° C. As the melt, a polymer is used containing component A in the form of a homo- and / or copolymer of ethylene with a density of 0.910-0.960 g / cm ³ , component B in the form of a homo- and / or copolymer of propylene with a density of 0.860-0.920 g / cm ³ , and stabilizer selected from the series: pentaerythrol tetrakis-3- (3,5-ditretbutyl-4-hydroxyphenyl) propionate, 2,6-di-tert-butyl-para-cresol, tris (2,4-di-tert-butylphenyl) phosphite, disteryl thiodipropionate, with the following components:

component a from 49.2% to 89.9% component b from 10% to 50% stabilizer from 0.1% to 0.8%.

A glass tape obtained from a web formed by dragging glass roving through a system of rolls that fluff out the filaments during bending and impregnated with a polymer melt including a homo- and / or copolymer of ethylene, a homo- and / or copolymer of propylene and the stabilizer proposed in the invention allows the application of the stabilizer it to the pipe reliably protect the anti-corrosion coating. The glass tape described in the invention has excellent adhesion when applied to an anti-corrosion coating with heating above 160 ° C. At the same time, the glass tape easily withstands any effects of sharp edges of stones, rocky soil, ice in permafrost soils when dragging the pipeline during construction.

The invention provides a method for applying a protective fiberglass coating to a steel pipe, according to which the steel pipe is mounted on the drive rollers of the winding machine, and, rotating the pipe, wind the glass tape on it, while before the glass tape enters the pipe, the glass tape and the pipe are heated to a temperature not using a hair dryer less than 160 ° C, while the tension of the glass tape during winding is selected in the range from 380 to 820 N. The method allows you to select the most suitable process parameters. To expand the possibilities of selecting the optimal process parameters for winding glass tape on the pipe, it is preferable to use two hair dryers, with the first hair dryer designed to heat the glass tape, and the second hair dryer designed to heat the outer surface of the pipe. Protective fiberglass coating made of glass tape applied to the pipe by the proposed method, has high adhesion to the corrosion-resistant coating of the pipe. Moreover, the presence of fiberglass allows you to get a coating with high hardness. Selection of glass tape tension during winding makes it possible to obtain an external surface without wrinkles or wrinkles. These factors make it possible to create a pipe with a protective coating capable of withstanding any effects of sharp edges of stones, rocky soil, ice in permafrost soils when dragging the pipeline during construction.

To apply glass tape to a steel pipe in order to obtain a protective fiberglass coating, according to the invention, it is proposed to use a device consisting of a winding machine with drive rollers for installing a steel pipe and a forming path with tensioners for installing a glass tape reel. At least one hair dryer for heating the glass tape and the surface of the steel pipe must be installed in the zone where the glass tape enters the pipe. In this case, it is desirable to use two hair dryers, the first hair dryer used to heat the glass tape, and the second to heat the pipe. The nozzle of the first and second hair dryer is made in the form of a flat socket. This allows you to create uniform heating of the glass tape and the outer surface of the pipe.

Thus, a device for applying glass tape to a steel pipe makes it possible to obtain a protective fiberglass coating that can withstand any effects of sharp edges of stones, rocky soil, ice in permafrost soils when dragging the pipeline during construction.

The pipe is equipped with a protective fiberglass coating of glass tape, including a glass roving impregnated with a polymer melt, the fabric is formed by unwinding the glass roving from the spools and dragging the glass roving through a system of rolls that fluff the threads during bending, and the formed web is impregnated with the polymer melt at a melt temperature of from 100 to 250 ° FROM. As the melt, polyethylene containing component A in the form of a homo- and / or ethylene copolymer with a density of 0.910-0.960 g / cm3, component B in the form of a homo- and / or copolymer of propylene with a density of 0.860-0.920 g / cm3 and a stabilizer selected from the series: pentaerythrol tetrakis-3- (3,5-ditretbutyl-4-hydroxyphenyl) propionate, 2,6-di-tert-butyl-para-cresol, tris (2,4-di-tert-butylphenyl) phosphite, disteryl thiodipropionate, with the following components:

component a from 49.2% to 89.9% component b from 10% to 50% stabilizer from 0.1% to 0.8%.

The implementation of the pipe according to the invention allows to obtain a protective fiberglass coating of glass tape with high adhesion to the anticorrosive layer covering the pipe, with high hardness and a flat surface, eliminating the formation of wrinkles and wrinkles, which solves the problem of withstanding any effects of sharp edges of stones, rocky soil, ice in permafrost soil, etc. when pulling the pipeline during the construction process.

In the following, the claimed invention is illustrated by a detailed description of a specific, but not limiting, solution of an example embodiment of a device and method for applying a protective fiberglass coating and the accompanying drawings, in which:

FIG. 1 is a schematic top view of a device for applying a protective fiberglass coating to a steel pipe;

FIG. 2 is a schematic side view of a device for applying a protective fiberglass coating to a steel pipe;

FIG. 3 - schematically shows a view of a device for applying a protective fiberglass coating on a steel pipe from the operator, the pipe is not shown.

For the manufacture of a pipe with a fiberglass coating according to the invention, a glass tape is required.

A glass tape is obtained by impregnating with a polymer a preformed glass roving web. For example, you can use glass roving from glass type E with an index of TECH 1200 or 2400.

The canvas is formed during glass unwinding from a spool, alignment through a system of shafts that fluff the thread during bending to the size of a single filament, and a certain pulling force when dragging. At the same time, up to 250 spools are subjected to this procedure, which creates a distributed web divided into separate threads. After the formation of the distributed web, the threads are pulled through an S-shaped forming tool equipped with rolls. The threads, repeatedly passing through the rolls, are bent. The formed web is impregnated with a polymer melt at a melt temperature of 100 to 250 ° C. The polymer melt with a temperature of less than 100 ° C has a low flow rate, which will lead to the fact that the formed fabric will be impregnated unevenly, that is, there will be sections of the fabric without polymer, which will reduce the resistance of the applied coating to the effects of sharp edges of stones, rocky soil, ice in permafrost soils, etc. when pulling the pipeline during the construction process. At a polymer melt temperature of more than 250 ° C, on the contrary, a high yield index will result in the sheet being poorly impregnated, which will reduce the adhesive properties of the formed sheet and, as a result, reduce the hardness of the coating, i.e., reduce the resistance of the applied coating to the influence of sharp edges of stones, rocky soil, ice in permafrost soils.

The polymer melt contains at least component A in the form of one ethylene homo- or copolymer having a density of 0.910-0.960 g / cm3 and at least component B in the form of one propylene homo- or copolymer having a density of 0.860- 0.920 g / cm ³ . The indicated density of ethylene and propylene makes it possible to obtain a melt for glass roving impregnation with optimal adhesion values.

Component A may be high density polyethylene (HDPE) or a mixture of high density polyethylene and low density polyethylene (LDPE). The copolymers include alpha olefins containing from 3 to 30 carbon atoms, for example, propylene, 1-butene, 1-pentene, 1-hexene. The melt flow rate (190 / 2.16) for one of the polyethylenes A is at least 30.0 g / 10 min, preferably 30.0-60.0 g / 10 min. Moreover, the content of component A in the final product should be 49.2-89.9%.

Component B may be: polypropylene or a copolymer of propylene and ethylene. Component B is grafted with a functional monomer. An example of grafted monomers can be carboxylic acids and their derivatives, for example, maleic, fumaric and itaconic. Maleic anhydride is most preferred. The grafting is carried out by heating the grafted polymers at elevated temperatures (150-280 ° C) in the presence of a radical initiator, for example, tert-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, di-tert-butyl peroxide, tert-butylcumene peroxide, methyl ethyl ketone peroxide. The amount of grafted monomer is chosen appropriately to obtain 0.1-0.5% maleic anhydride in the final composition. The amount of grafted maleic anhydride is determined using infrared spectroscopy. The melt flow rate (190 / 2.16) is preferably 15.0-60.0 g / 10 min. The content of component B in the final product should be 10-50%.

In addition, the polymer melt must contain a complex of stabilizers. Examples of system stabilizers are: Pentaerythrol tetrakis-3- (3,5-ditretbutyl-4-hydroxyphenyl) propionate; 2,6-di-tert-butyl-para-cresol; tris (2,4-di-tert-butylphenyl) phosphite; disteryl thiodipropionate. Their content in the final product should be 0.1-0.8%. The melt temperature in the production of polymer melt should be from 100 ° C to 250 ° C.

If the ratio of components exceeds the limits indicated in the table, the final tensile strength of the tape decreases and is at the level of not more than 600 MPa. Finished glass tape is wound on bobbins.

Thus, a glass tape is obtained, for example, 650 mm wide and 0.3 mm thick. It is possible to vary the width of the glass tape, cutting it, for example, to a width of 50 mm.

The thickness of the protective fiberglass coating can be different depending on the purpose and requirements. Depending on the thickness, a change in the winding pattern and pitch is possible.

To apply a protective fiberglass coating to a steel pipe, a glass tape is prepared, for example, by cutting it to the required width.

Then the anticorrosive coated steel pipe is mounted on a device for applying a protective fiberglass coating. The following coatings can be used as an anti-corrosion coating: polyethylene, polypropylene and epoxy.

Schematically, a device for applying a protective fiberglass coating is shown in FIG. 1, FIG. 2 and FIG. 3.

The device is a winding machine. The steel pipe 1 with a corrosion-resistant coating is installed on the drive rollers 2 of the winding machine. On the forming path 3 install the reel 4 with a glass tape 5.

The operator 6, which controls the process of winding the glass tape 5 on the steel pipe 1, is located on the carriage 8 moving along the carriages 7 parallel to the steel pipe 1. At the same time, the forming path 3 is moved along with the carriage 8 with the reel 4 mounted on it with glass tape 5. Moving the carriage 8 provides a drive 9, shown schematically in FIG. 1.

In the forming path 3 installed two hair dryers.

The first hair dryer 10 is designed to heat the glass tape 5, going into the steel pipe 1 with an anti-corrosion coating. The first hair dryer 10 is equipped with a flat bell 11 for uniform heating of the entire width of the glass tape 5 before it touches the surface of the steel pipe 1 and, partially, with glass tape 5 already wound on the steel pipe 1. Also, the first hair dryer can be made in the form of a tunnel nozzle (not shown shown), which improves the efficiency of the input heat. The second hair dryer 12 is designed to heat directly the surface of the anticorrosion coating of the steel pipe 1 and partially, with the glass tape 5 already wound on the pipe 1, before the winding glass tape 5 comes into contact with it. The second hair dryer 12 is also equipped with a flat socket 13.

In order for the temperature at the place of winding the glass tape on the pipe to be no lower than 160 ° C, the temperature on the hair dryers is set in the range from 250 ° C to 600 ° C, depending on the speed of winding.

Winding glass tape 5 on the surface of a rotating steel pipe 1 is made according to a predetermined program. For this, temperature and tension sensors of glass tape 5 are installed in the forming path 3 (not shown in the drawings). Data received from sensors located in the forming path 3 is transmitted to the control cabinet 14. If necessary, the heating temperature supplied by the first hairdryer 10 and the second hairdryer 12 can be adjusted. It is also possible to adjust the tension of the glass tape 5 when winding onto steel pipe 1. In this case, tensioners 15 are used. The tension during winding should be in the range from 380 to 820 N. When the tension is less than 380 N, the tape can sag and wrinkles can be formed during winding. At the place of wrinkling, the adhesion properties of the glass tape deteriorate and when the pipeline is pulled in these places, the coating tears off and the pipe surface is damaged. If the tension exceeds 820 N, then the probability of breaking the glass tape is high, which also affects the quality of the coating of the pipeline. It is also possible to adjust the speed of the carriage 8 with the forming path 3 and the reel 4 mounted on it with glass tape 5 and the rotation speed of the steel pipe 1 by changing the rotation speed of the drive rollers 2. This allows you to adjust the winding angle β of the glass tape 5, and, accordingly, the thickness of the protective fiberglass coating.

The presence of temperature sensors of the glass tape 5 makes it possible to prevent heating of the glass tape 5 below the melting temperature of the binder during winding, that is, to maintain the heating range of the tape 160-180 ° C. If the temperature of the glass tape 5 is lower, there will be no thermal bonding of the layers of glass tape 5 with each other, as well as with an anti-corrosion coating of the steel pipe 1.

After winding the glass tape 5, the steel pipe 1 with the finished protective fiberglass coating cools on the machine.

The thickness of the protective fiberglass coating can be different depending on the purpose and requirements. Depending on the required thickness, a change in the winding pattern and pitch is possible.

With a maximum thickness of 7 mm, the protective fiberglass coating will be wound in two or three passes. The beginning of the winding is made from one edge of the steel pipe 1, reaches the other, unfolds and returns to the starting point. In this case, the winding pitch will be from 50 mm to 150 mm / rev and the angle β of winding the glass tape 5 is about 10 °. With a minimum thickness of the protective fiberglass coating of 3 mm, the winding is produced in one pass and the angle β of winding the glass tape 5 is about 20 °.

Thus, the protective fiberglass coating applied to the pipe according to the invention reliably isolates the factory anti-corrosion coating of the pipe from mechanical damage during installation and operation of the pipeline. The strength of the protective fiberglass coating is significantly higher than the currently used standard coatings of polyethylene and polypropylene. Accordingly, the probability of corrosion of the steel pipe due to damage to the anti-corrosion coating becomes minimal. The use of a protective fiberglass coating made according to the invention leads to an increase in the service life of the constructed pipeline.

Claims (14)

1. Glass tape for applying a protective fiberglass coating to a pipe, including a glass roving fabric impregnated with a molten polyethylene, characterized in that the fabric is formed by unwinding glass roving from the spools and dragging glass roving through a system of rolls that fluff the threads during bending, the formed fabric is impregnated with a polymer melt at a melt temperature from 100 ° C to 250 ° C, polyethylene containing component A in the form of a homo- and / or ethylene copolymer with a density of 0.910-0.960 g / cm ³ , component B in the form of a homo- and / or copolymer of propylene with a density 0.860-0.920 g / cm ³ and a stabilizer selected from the series: pentaerythrol tetrakis-3- (3,5-ditretbutyl-4-hydroxyphenyl) propionate, 2,6-di-tert-butyl-para-cresol, tris (2, 4-di-tert-butylphenyl) phosphite, disteryl thiodipropionate, with the following components: component A from 49.2% to 89.9%, component B from 10% to 50%, stabilizer from 0.1% to 0.8%. 2. The method of applying glass tape according to claim 1 on a steel pipe, which consists in the fact that the steel pipe is mounted on the drive rollers of the winding machine and, rotating the pipe, wind a glass tape on it, characterized in that when winding the glass tape on the pipe before the glass comes in, the glass tape and pipe heated with at least one hair dryer to a temperature of at least 160 ° C, while the tension of the glass tape during winding should be in the range from 380 to 820 N. 3. The method according to p. 2, characterized in that when winding before entering the glass tape on the pipe, the glass tape is heated with one hair dryer to a temperature of at least 160 ° C and the pipe is heated with a second hair dryer to a temperature of at least 160 ° C, while the glass tape tension is winding should be in the range from 380 to 820 N. 4. A device for applying glass tape according to claim 1 to a steel pipe, consisting of a winding machine with drive rollers for installing a steel pipe and a forming path with tensioners for installing a reel with a glass tape, characterized in that at least in the zone of glass tape entry onto the pipe one hair dryer for heating the glass tape and the surface of the steel pipe. 5. The device according to claim 4, characterized in that in the zone of entry of the glass tape to the pipe there are two hair dryers, one hair dryer for heating the glass tape and a second hair dryer for heating the surface of the steel pipe. 6. The device according to p. 5, characterized in that the nozzle of the first and second hair dryer is made in the form of a flat socket. 7. The device according to p. 5, characterized in that the nozzle of the first hairdryer is made in the form of a tunnel nozzle, and the second hairdryer in the form of a flat bell. 8. A pipe with a protective fiberglass coating, characterized in that the protective coating is made of glass tape, including a glass roving impregnated with a polymer melt, the fabric is formed by unwinding glass roving from spools and dragging glass roving through a system of rolls that fluff the threads during bending, the formed fabric is impregnated polymer melt at a melt temperature from 100 ° C to 250 ° C. Polyethylene containing component A in the form of a homo- and / or ethylene copolymer with a density of 0.910-0.960 g / cm ³ , component B in the form of homo- and / or a propylene copolymer with a density of 0.860-0.920 g / cm ³ and a stabilizer selected from the series: pentaerythrol tetrakis-3- (3,5-ditretbutyl-4-hydroxyphenyl) propionate, 2,6-di-tert-butyl-para-cresol , tris (2,4-di-tert-butylphenyl) phosphite, disteryl thiodipropionate, with the following components: component A from 49.2% to 89.9%, component B from 10% to 50%, stabilizer from 0.1% to 0.8%.

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