Stainless steel pipe with high stability and forming process thereof

Abstract

The invention discloses a high-stability stainless steel pipe and a forming process thereof, and relates to the technical field of stainless steel pipe machining, the high-stability stainless steel pipe comprises a stainless steel pipe blank machined and manufactured by a stainless steel coil and a reinforcing film adhered to the inner wall of the stainless steel pipe blank, and the reinforcing film completely covers the inner wall of the stainless steel pipe blank. The reinforcing film is mainly composed of borosilicate, a transparent tackifying filling master batch is added into the reinforcing film, and the mass ratio of the transparent tackifying filling master batch to the borosilicate is 1: 2; the reinforced film is added and compounded on the inner wall of the stainless steel pipe, the oil resistance is further improved on the basis that the overall physicochemical property is improved, the overall light resistance of the stainless steel pipe is not changed after the reinforced film is attached, and the interior of the stainless steel pipe can be conveniently detected through objects.

Description

Technical Field

[0001] This invention belongs to the field of stainless steel pipe processing technology, and particularly relates to a highly stable stainless steel pipe and its forming process. Background Technology

[0002] Stainless steel pipe is a hollow, long, round steel material, widely used in industrial pipelines for petroleum, chemical, medical, food, light industry, and machinery, as well as in mechanical structural components. Additionally, it is lighter in weight while maintaining the same bending and torsional strength, making it widely used in the manufacture of mechanical parts and engineering structures. It is also commonly used in furniture and kitchenware.

[0003] Due to its diverse applications, and the fact that its interior is often filled with liquids of different acids, alkalis, and corrosive properties, stainless steel pipes are easily corroded during conventional use, which can further improve their physical and chemical stability. Summary of the Invention

[0004] The purpose of this invention is to provide a highly stable stainless steel tube and its forming process. The stainless steel tube has a cooling function. After polishing, in order to control the temperature rise after the skin peels off the feet, a metal plate is used to fit the foot and move, thereby improving the comfort after the skin is polished.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A highly stable stainless steel pipe and its forming process include a stainless steel pipe blank made from a stainless steel coil, a reinforcing film adhered to the inner wall of the stainless steel pipe blank, the reinforcing film completely covering the inner wall of the stainless steel pipe blank, the reinforcing film mainly composed of borosilicate, and containing a transparent adhesive filler masterbatch, the mass ratio of the transparent adhesive filler masterbatch to borosilicate being 1:2.

[0006] As a preferred embodiment of the present invention, the raw materials of the transparent tackifying filler masterbatch are divided into the following components by weight: 100-120 parts of high molecular weight polyethylene, 20-30 parts of modified tackifier, and 2-5 parts of thixotropic agent.

[0007] In a preferred embodiment of the present invention, the thixotropic agent is silica.

[0008] This invention also provides a forming process for a highly stable stainless steel tube, using the aforementioned raw materials, specifically including the following steps: (a) High molecular weight polyethylene, modified tackifier and thixotropic agent are fed into a granulator; (b) Start the granulator, and extrude coarse particles after the input is conveyed, melted, mixed and homogenized by the granulator; (c) The coarse particles obtained in the previous step are granulated underwater or in a water ring, dried, and vibrated and classified before being put into a homogenization bin for centralized storage, thus obtaining the finished transparent thickening filler masterbatch for stainless steel pipe protective film. (d) The obtained transparent thickening filler masterbatch is added and mixed with borosilicate in the corresponding mass ratio, and heated to 60°C to a molten state; (c) The above-mentioned molten mixture is uniformly coated on the inner wall of the stainless steel pipe blank, dried, the inner and outer walls of the stainless steel pipe are polished, and the outer side is polished to obtain the stainless steel pipe.

[0009] As a preferred embodiment of the present invention, the method for preparing the high molecular weight polyethylene includes the following steps: (1) Add ethylene monomer to a first reactor containing α-olefin comonomer, main catalyst, co-catalyst and a large amount of organic solvent. Introduce hydrogen into the first reactor, seal the reactor, and polymerize for 3 hours under the conditions of pressure of 0.1MPa~4.0MPa and temperature of 50-85℃. After the reaction is completed, stop introducing hydrogen and cool down to obtain a slurry suspension. (2) The slurry suspension obtained in step (1) is sent to a flash tank to remove small molecule monomer components by flash evaporation, and then placed into the second reaction vessel; (3) Add α-olefin comonomer, main catalyst and co-catalyst to the second reactor, and introduce hydrogen again. The reaction takes place at the same pressure and temperature as in step (1) for 2 hours to obtain the polymerization product. (4) The polymer product obtained in step (3) is degassed and cooled to obtain high molecular weight polyethylene.

[0010] As a preferred embodiment of the present invention, the following components are prepared in parts by weight: 50-60 parts of ethylene monomer, 15-20 parts of α-olefin comonomer, 3-5 parts of main catalyst, 2-3 parts of cocatalyst, and 90-120 parts of hydrogen. The α-olefin comonomer is selected from one or more of propylene, butene-1, and hexene-1. The main catalyst is a supported metallocene catalyst, and the cocatalyst is selected from one or more of trimethylaluminum, triisobutylaluminum, dimethylaluminum chloride, diisobutylaluminum chloride, and ethylaluminum chloride.

[0011] In a preferred embodiment of the present invention, the organic solvent is selected from one or more of propane, butane, isobutane, pentane, hexane, and cyclohexane.

[0012] As a preferred embodiment of the present invention, the method for preparing the improved tackifier includes the following steps: (1) Mix p-tert-octylphenol, toluene, and barium hydroxide, and heat to 140-150℃ and reflux for dehydration reaction for 4.5h; (2) After dehydration, slowly add formaldehyde solution and heat to 100-110℃ and reflux for 4-5 hours; (3) Neutralize with sulfuric acid, wash with water, and then distill to remove volatiles under negative pressure of 0.06-0.09 MPa and kettle temperature of 200-220℃. After 30 minutes, take a sample to measure the softening point. When it reaches 125-150℃, discharge the material to obtain the tackifying resin, which is a modified tackifier.

[0013] As a preferred embodiment of the present invention, it is prepared according to the following components in parts by weight: 25-35 parts of p-tert-octylphenol, 100-110 parts of toluene, and 1-3 parts of barium hydroxide.

[0014] In a preferred embodiment of the present invention, the formaldehyde solution concentration is 38%.

[0015] In summary, the beneficial technical effects of this invention are as follows: a composite reinforcing film is added to the inner wall of the stainless steel pipe. One component of the reinforcing film is high molecular weight polyethylene. High molecular weight polyethylene has good heat aging resistance, flame retardancy, chemical resistance and oil resistance. At the same time, it has high transparency, which can enhance its protective performance without affecting the transparency of the reinforcing film. This can improve the overall physical and chemical properties of the stainless steel pipe and further improve its oil resistance. Moreover, the reinforcement film does not change the overall light blocking property of the stainless steel pipe after it is attached, which facilitates the detection of objects passing through it. Detailed Implementation

[0016] The present invention will now be described in further detail.

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0018] The present invention provides a technical solution: a highly stable stainless steel pipe and its forming process, comprising a stainless steel pipe blank made from a stainless steel coil, a reinforcing film adhered to the inner wall of the stainless steel pipe blank, the reinforcing film completely covering the inner wall of the stainless steel pipe blank, the reinforcing film being mainly composed of borosilicate, and containing a transparent adhesive filler masterbatch, the mass ratio of the transparent adhesive filler masterbatch to borosilicate being 1:2.

[0019] The raw materials of the transparent tackifying filler masterbatch are divided into the following components by weight: 100-120 parts of high molecular weight polyethylene, 20-30 parts of modified tackifier, and 2-5 parts of thixotropic agent.

[0020] The thixotropic agent is silica.

[0021] In this invention, unless otherwise specified, all raw material components are commercially available products well known to those skilled in the art, wherein, Highly chlorinated polyethylene, CAS No.: 140-66-9; Metallocene catalyst, CAS No.: 456789; Silica, CAS No.: 179-10-6; Barium hydroxide, CAS No.: 17194-00-2.

[0022] The stainless steel tube is prepared using the following steps: (a) High molecular weight polyethylene, modified tackifier and thixotropic agent are fed into a granulator; (b) Start the granulator, and extrude coarse particles after the input is conveyed, melted, mixed and homogenized by the granulator; (c) The coarse particles obtained in the previous step are granulated underwater or in a water ring, dried, and vibrated and classified before being put into a homogenization bin for centralized storage, thus obtaining the finished transparent thickening filler masterbatch for stainless steel pipe protective film. (d) The obtained transparent thickening filler masterbatch is added and mixed with borosilicate in the corresponding mass ratio, and heated to 60°C to a molten state; (c) The above-mentioned molten mixture is uniformly coated on the inner wall of the stainless steel pipe blank, dried, the inner and outer walls of the stainless steel pipe are polished, and the outer side is polished to obtain the stainless steel pipe.

[0023] The preparation method of high molecular weight polyethylene includes the following steps: (1) Add ethylene monomer to a first reactor containing α-olefin comonomer, main catalyst, co-catalyst and a large amount of organic solvent. Introduce hydrogen into the first reactor, seal the reactor, and polymerize for 3 hours under the conditions of pressure of 0.1MPa~4.0MPa and temperature of 50-85℃. After the reaction is completed, stop introducing hydrogen and cool down to obtain a slurry suspension. (2) The slurry suspension obtained in step (1) is sent to a flash tank to remove small molecule monomer components by flash evaporation, and then placed into the second reaction vessel; (3) Add α-olefin comonomer, main catalyst and co-catalyst to the second reactor, and introduce hydrogen again. The reaction takes place at the same pressure and temperature as in step (1) for 2 hours to obtain the polymerization product. (4) The polymer product obtained in step (3) is degassed and cooled to obtain high molecular weight polyethylene.

[0024] Prepared according to the following components in parts by weight: 50-60 parts ethylene monomer, 15-20 parts α-olefin comonomer, 3-5 parts main catalyst, 2-3 parts cocatalyst, and 90-120 parts hydrogen. The α-olefin comonomer is selected from one or more of propylene, butene-1, and hexene-1. The main catalyst is a supported metallocene catalyst, and the cocatalyst is selected from one or more of trimethylaluminum, triisobutylaluminum, dimethylaluminum chloride, diisobutylaluminum chloride, and ethylaluminum chloride.

[0025] The organic solvent is selected from one or more of propane, butane, isobutane, pentane, hexane, and cyclohexane.

[0026] The preparation method of the improved thickener includes the following steps: (1) Mix p-tert-octylphenol, toluene, and barium hydroxide, and heat to 140-150℃ and reflux for dehydration reaction for 4.5h; (2) After dehydration, slowly add formaldehyde solution and heat to 100-110℃ and reflux for 4-5 hours; (3) Neutralize with sulfuric acid, wash with water, and then distill to remove volatiles under negative pressure of 0.06-0.09 MPa and kettle temperature of 200-220℃. After 30 minutes, take a sample to measure the softening point. When it reaches 125-150℃, discharge the material to obtain the tackifying resin, which is a modified tackifier.

[0027] Prepared according to the following components in parts by weight: 25-35 parts of p-tert-octylphenol, 100-110 parts of toluene, and 1-3 parts of barium hydroxide.

[0028] The formaldehyde solution concentration is 38%.

[0029] Examples 1-6 The raw materials are weighed in parts by weight: 100 parts of high molecular weight polyethylene, 20 parts of modified tackifier, and 3 parts of thixotropic agent.

[0030] One of the raw material components is thixotropic agent, which is silica.

[0031] The high molecular weight polyethylene is prepared according to the following steps: (1) Add ethylene monomer to a first reactor containing α-olefin comonomer, main catalyst, co-catalyst and a large amount of organic solvent. Introduce hydrogen into the first reactor, seal the reactor, and polymerize for 3 hours under the conditions of pressure of 0.1MPa~4.0MPa and temperature of 50-85℃. After the reaction is completed, stop introducing hydrogen and cool down to obtain a slurry suspension. (2) The slurry suspension obtained in step (1) is sent to a flash tank to remove small molecule monomer components by flash evaporation, and then placed into the second reaction vessel; (3) Add α-olefin comonomer, main catalyst and co-catalyst to the second reactor, and introduce hydrogen again. The reaction takes place at the same pressure and temperature as in step (1) for 2 hours to obtain the polymerization product. (4) The polymer product obtained in step (3) is degassed and cooled to obtain high molecular weight polyethylene.

[0032] In the preparation of the above-mentioned high molecular weight polyethylene, the components are weighed in parts by weight as follows: 50 parts of ethylene monomer, 15 parts of α-olefin comonomer, 3 parts of main catalyst, 2 parts of co-catalyst, and 90 parts of hydrogen.

[0033] The organic solvent is selected from one or more of propane, butane, isobutane, pentane, hexane, and cyclohexane; the α-olefin comonomer is selected from one or more of propylene, butene-1, and hexene-1; the main catalyst is a supported metallocene catalyst; and the cocatalyst is selected from one or more of trimethylaluminum, triisobutylaluminum, dimethylaluminum chloride, diisobutylaluminum chloride, and ethylaluminum chloride.

[0034] The modified thickener is prepared according to the following steps: (1) Mix p-tert-octylphenol, toluene, and barium hydroxide, and heat to 140°C and reflux for dehydration reaction for 4.5 h; (2) After dehydration, slowly add a 38% formaldehyde solution and heat to 100°C and reflux for 4 hours; (3) Neutralize with sulfuric acid, wash with water, and then distill to remove volatiles under negative pressure of 0.06-0.09 MPa and kettle temperature of 210℃. After 30 minutes, take a sample to measure the softening point. When it reaches 125-150℃, discharge the material to obtain the tackifying resin, which is a modified tackifier.

[0035] In the preparation of the above-mentioned improved thickener, the components are weighed in the following proportions by weight: 25 parts of p-tert-octylphenol, 100 parts of toluene, and 1.5 parts of barium hydroxide.

[0036] A method for preparing a transparent thickening filler masterbatch for a protective film on stainless steel pipes, specifically including the following steps: (a) High molecular weight polyethylene, modified tackifier and thixotropic agent are fed into a granulator; (b) Start the granulator, and extrude coarse particles after the input is conveyed, melted, mixed and homogenized by the granulator; (c) The coarse particles obtained in the previous step are granulated underwater or in a water ring, dried, and vibrated and classified before being put into a homogenization chamber for centralized storage, thus obtaining the finished product of transparent thickening filler masterbatch for stainless steel pipe protective film.

[0037] The proportions of each group in Examples 2-4 are different from those in Example 1, as shown in Table 1: Examples 5-7 The difference between Examples 5-7 and Example 4 is that the proportions of the high molecular weight polyethylene components are different, as shown in Table 2: Examples 8-10 The difference between Examples 8-10 and Example 4 is that the proportions of the modified tackifier components are different, as shown in Table 3: Comparative Example 1 Compared to Example 4, Comparative Example 1 replaced high molecular weight polyethylene with an equal amount of commercially available common polyethylene.

[0038] The preparation method is as follows: all raw materials are put into a granulator according to the same proportion as in Example 4, wherein high molecular weight polyethylene is replaced with commercially available polyethylene. The granulator is started first, and the input is conveyed, melted, mixed and homogenized by the granulator and then extruded into coarse particles. The obtained coarse particles are then cut into pellets underwater or in a water ring, dried, vibrated and classified, and then put into a homogenization chamber for centralized storage, thus obtaining the finished transparent thickening filler masterbatch for stainless steel pipe protective film.

[0039] Comparative Example 2 Compared to Example 4, in Comparative Example 2, commercially available polypropylene replaced high molecular weight polyethylene.

[0040] The preparation steps of Comparative Example 2 are the same as those of Comparative Example 1. After preparation, a transparent thickening filler masterbatch for stainless steel pipe protective film is obtained.

[0041] Comparative Example 3 Compared with Example 9, the modified tackifier in Comparative Example 3 was replaced by a commercially available tackifier, petroleum resin, with CAS number 64741-16-1.

[0042] The preparation steps of Comparative Example 3 were the same as those of Comparative Example 1, and the finished product was a transparent thickening filler masterbatch for stainless steel pipe protective film.

[0043] Comparative Example 4 Compared to Example 9, the modified tackifier in Comparative Example 4 was replaced with a commercially available common silicone resin.

[0044] The preparation steps of Comparative Example 4 were the same as those of Comparative Example 1, and the finished product was a transparent thickening filler masterbatch for stainless steel pipe protective film.

[0045] Comparative Example 5 Compared with Example 4, Comparative Example 5 replaced high molecular weight polyethylene with commercially available polypropylene without adding a modified tackifier, while keeping the proportions of other components unchanged. The finished product of transparent tackifying filler masterbatch for stainless steel pipe protective film was obtained by processing according to the same preparation steps as Comparative Example 1.

[0046] Regarding protective performance, the transparent tackifying filler masterbatches prepared in Examples 1-10 and Comparative Examples 1-5 were divided into 15 groups and filled into stainless steel pipe protective films of the same batch and type. The number of scratches and punctures before the notch appeared in each group was recorded, and the scratch resistance and puncture resistance of different groups were compared. The results are shown in Table 4. Regarding the thickening function, the finished transparent thickening filler masterbatches prepared in Examples 1-10 and Comparative Examples 1-5 were divided into 15 groups and filled with stainless steel pipe protective films of the same batch and model. Each group of protective films was cut into thin pieces of equal area and then wrapped onto the same aluminum alloy plate in an alternating order. The protective films were then pulled apart using a pull hook, and the pulling force required for the protective film to completely detach from the aluminum alloy plate was compared. The results are shown in Table 5. As can be seen from Examples 1-10, Comparative Examples 1-5 and Table 4, the stainless steel pipe protective film made from the transparent tackifying filler masterbatch prepared in this application has stronger scratch and puncture resistance characteristics than the protective film made from ordinary polyethylene and polypropylene. Among them, Examples 2 and 5-7 have relatively more scratch resistance and puncture resistance, and they contain a higher proportion of high molecular weight polyethylene.

[0047] As can be seen from Examples 1-10, Comparative Examples 1-5, and Table 5, the stainless steel pipe protective film made from the transparent tackifying filler masterbatch prepared in this application has stronger adhesion to stainless steel pipes compared to protective films containing commercially available tackifiers. This filler masterbatch has strong adhesion, thereby improving the adhesion of the protective film. Among them, Examples 3, 4, and 8-10 require relatively large tensile forces, and they also contain a higher proportion of tackifier than the other groups.

[0048] Based on the differences between Examples 1-10 and Comparative Examples 1-5, the transparent tackifying filler masterbatch of the stainless steel pipe protective film of this application has strong protective performance and great adhesion. The stainless steel pipe protective film made from it can significantly reduce scratches and wear caused during transportation compared with ordinary stainless steel pipe protective films, and is not easy to fall off, thus covering the surface of stainless steel pipe for a long time and greatly increasing the durability of protection.

[0049] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0050] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A stainless steel pipe having high stability, characterized by, The stainless steel pipe blank is made of a stainless steel coil, and a reinforcing film is adhered to the inner wall of the stainless steel pipe blank, wherein the reinforcing film completely covers the inner wall of the stainless steel pipe blank, and the reinforcing film is mainly composed of borosilicate and internally added with transparent adhesion filling masterbatch, and the mass ratio of the transparent adhesion filling masterbatch to the borosilicate is 1:

2.

2. The strongly stable stainless steel pipe according to claim 1, characterized by The raw materials of the transparent adhesion filling masterbatch include the following components by weight: 100-120 parts of high molecular weight polyethylene, 20-30 parts of modified adhesion agent, and 2-5 parts of thixotropic agent.

3. The strongly stabilized stainless steel pipe according to claim 2, characterized by, The thixotropic agent is white carbon black.

4. A forming process of a strong-stability stainless steel pipe using the raw material of claim 1, characterized by, The method specifically comprises the following steps: (a) putting the high molecular weight polyethylene, the modified adhesion agent and the thixotropic agent into a granulator; (b) starting the granulator to convey, melt, mix and homogenize the input materials, and then extruding coarse particles; (c) cutting the coarse particles obtained in the previous step underwater or by a water ring, drying, and then classifying by vibration to obtain the transparent adhesion filling masterbatch of the stainless steel pipe protection film; (d) mixing the obtained transparent adhesion filling masterbatch with borosilicate according to the corresponding mass ratio, and heating to 60 DEG C to be in a molten state; (c) uniformly coating the mixture in the molten state on the inner wall of the stainless steel pipe blank, drying, polishing the inner and outer walls of the stainless steel pipe, and polishing the outer side to obtain the stainless steel pipe.

5. The forming process of a strong-stability stainless steel pipe according to claim 4, characterized by, The preparation method of the high molecular weight polyethylene comprises the following steps: (1) adding ethylene monomer into a first reaction kettle containing alpha-olefin comonomer, main catalyst, auxiliary catalyst and a large amount of organic solvent, introducing hydrogen into the first reaction kettle, sealing the reaction kettle, and polymerizing for 3 hours under the conditions of a pressure of 0.1-4.0 MPa and a temperature of 50-85 DEG C, stopping the introduction of hydrogen and cooling after the reaction is completed, and obtaining slurry suspension; (2) sending the slurry suspension obtained in step (1) to a flash tank to remove small molecule monomer components by flashing, and then putting into a second reaction kettle; (3) adding alpha-olefin comonomer, main catalyst and auxiliary catalyst into the second reaction kettle, introducing hydrogen again, and reacting under the same pressure and temperature as in step (1) for 2 hours to obtain a polymerization product; (4) degassing and cooling the polymerization product obtained in step (3) to obtain high molecular weight polyethylene.

6. The forming process of a highly stable stainless steel pipe according to claim 5, characterized by, The components are prepared according to the following weight parts: 50-60 parts of ethylene monomer, 15-20 parts of alpha-olefin comonomer, 3-5 parts of main catalyst, 2-3 parts of auxiliary catalyst, and 90-120 parts of hydrogen, and the alpha-olefin comonomer is selected from one or more of propylene, butene-1 and hexene-1, the main catalyst is a supported metallocene catalyst, and the auxiliary catalyst is selected from one or more of trimethyl aluminum, triisobutyl aluminum, dimethyl aluminum chloride, diisobutyl aluminum chloride and ethyl aluminum dichloride.

7. The process for forming a strong and stable stainless steel tube according to claim 5, wherein The organic solvent is selected from one or more of propane, butane, isobutane, pentane, hexane and cyclohexane.

8. The process for forming a strong and stable stainless steel tube according to claim 4, wherein The preparation method of the modified adhesion agent comprises the following steps: (1) mixing p-tert-octylphenol, toluene and barium hydroxide, heating and warming to 140-150 DEG C to reflux and dehydrate for 4.5 hours; (2) after dehydration, slowly adding formaldehyde solution, and heating to 100-110 DEG C to reflux for 4-5 hours; (3) add sulfuric acid to neutralize, washed with water, in negative pressure 0.06~0.09mpa, kettle temperature 200~220 ℃ conditions under distillation dewatering, 30min after sampling to measure softening point reach 125~150 ℃, discharge, namely the tackifying resin, is improved tackifier.

9. The forming process of a strong and stable stainless steel pipe according to claim 8, wherein The following components are prepared according to the weight parts: p-tert-octyl phenol 25-35 parts, toluene 100-110 parts, barium hydroxide 1-3 parts.

10. The forming process of a strong and stable stainless steel pipe according to claim 8, wherein The formaldehyde solution concentration is 38%.

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