Plastic welding rod and preparation method and application thereof

Abstract

The invention provides a plastic welding rod and a preparation method and application thereof. The plastic welding rod is composed of iron powder, a PP material and a POE elastomer material. The mass ratio of the iron powder to the PP material to the POE elastomer material in the plastic welding rod is (70-80): (10-15): (10-15). The plastic welding rod provided by the invention is composed of iron powder, a pp material and a POE elastomer material, and can be prepared by extrusion molding through a mold with the size diameter of 2.0-3.0 mm; in addition, the plastic welding rod has the advantages of excellent welding effect, high-smoothness appearance, good flexibility and bendability at the same time.

Description

Technical Field

[0001] The invention belongs to the technical field of welding rods and relates to a plastic welding rod, in particular to a plastic welding rod and a preparation method and application thereof. Background Art

[0002] Plastic welding rods are currently in the rising stage of development. The product shape is mostly cylindrical and strip-shaped, and it needs to contain the characteristics of plastic materials. Therefore, plastic welding rods have physical properties such as flexibility, elasticity, and bending performance, and need to meet functional characteristics such as melting, softening and bonding under high temperature conditions, and high hardness and firmness under normal temperature conditions. However, most existing welding rods are made of a single material, that is, plastic welding rods or metal welding rods, which cannot meet the needs of practical applications.

[0003] CN105694348A discloses a welding rod, and more particularly, relates to a plastic welding rod. The welding rod is a solid strip structure, and the cross section of the plastic welding rod is a rectangle. The welding rod comprises plastic and metal powder, wherein the plastic mass percentage is 70-80%, and the metal powder mass percentage is 20-30%. The plastic is phenolic resin, polyethylene, polypropylene or polyvinyl chloride. The metal powder is copper powder, iron powder or aluminum powder. The plastic welding rod also includes a deoxidizer. The plastic welding rod prepared in the document can be applied to various plastic weldings, is firm after welding, is not easy to fall off, and is beautiful. However, the plastic welding rod is difficult to prepare by extrusion molding with a mold having a smaller diameter.

[0004] CN109367030A discloses a plastic welding rod, which is provided with a first clamping slot and a second clamping slot for inserting two welded parts and arranged in parallel with each other, and each clamping slot is provided with a protrusion that shrinks toward the inner side of the clamping slot to clamp the welded part, so that automatic welding can be realized, and when the plastic welding rod is used to weld pipes, it is not necessary to manufacture a socket, thereby improving welding efficiency and qualified rate and ensuring welding quality. However, the plastic welding rod is prepared by extrusion molding with a mold of a smaller diameter, and the plastic welding rod has poor flexibility and bendability.

[0005] The plastic welding rods disclosed in the prior art all have certain defects. There is a problem that it is difficult to prepare them by extrusion molding through a small-sized mold, and there is also a problem that it is difficult to have excellent welding effect, smooth appearance, good flexibility and bendability at the same time. Therefore, it is very important to develop and design a new type of plastic welding rod. Summary of the invention

[0006] In view of the deficiencies in the prior art, the object of the present invention is to provide a plastic welding rod and a preparation method and application thereof. The plastic welding rod provided by the present invention is composed of iron powder, PP material and POE elastomer material, and can be prepared by extrusion molding through a mold with a diameter of 2.0 to 3.0 mm; in addition, the plastic welding rod also has excellent welding effect, a smooth appearance, good flexibility and bendability.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a plastic welding rod, which is composed of iron powder, pp material and POE elastomer material; the mass ratio of iron powder, pp material and POE elastomer material in the plastic welding rod is (70-80):(10-15):(10-15).

[0009] The plastic welding rod provided by the present invention is composed of iron powder, PP material (polypropylene material) and POE elastomer material (polyolefin elastomer material), and has good fluidity, so that it can be prepared by extrusion molding through a mold with a size diameter of 2.0 to 3.0 mm; in addition, the plastic welding rod also has excellent welding effect, a smooth appearance, good flexibility and bendability.

[0010] The mass ratio of iron powder to PP material in the plastic welding rod provided by the present invention is (70-80):(10-15), for example, it can be 70:10, 70:11, 70:13, 70:15, 73:10, 73:11, 73:13, 73:15, 77:10, 77:13, 77:15, 80:10, 80:11, 80:13 or 80:15, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0011] The mass ratio of iron powder to POE elastomer material in the plastic welding rod provided by the present invention is (70-80):(10-15), for example, it can be 70:10, 70:11, 70:13, 70:15, 73:10, 73:11, 73:13, 73:15, 77:10, 77:13, 77:15, 80:10, 80:11, 80:13 or 80:15, but is not limited to the listed values, and other unlisted values ​​within the numerical range are equally applicable.

[0012] Preferably, the mass ratio of iron powder, PP material and POE elastomer material in the plastic welding rod is (75-80):(10-15):(10-12).

[0013] The mass ratio of iron powder to PP material in the plastic welding rod of the present invention is (75-80):(10-15), for example, it can be 75:10, 75:11, 75:13, 75:15, 79:10, 79:11, 79:13, 79:15, 80:10, 80:11, 80:13 or 80:15, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0014] The mass ratio of iron powder to POE elastomer material in the plastic welding rod of the present invention is (75-80):(10-12), for example, it can be 75:10, 75:11, 75:12, 79:10, 79:11, 79:12, 80:10, 80:11 or 80:12, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] Preferably, the iron powder includes spherical iron powder and / or flake iron powder.

[0016] Preferably, the average diameter of the plastic welding rod is 2.0-3.0 mm, for example, it can be 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm or 3.0 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] In a second aspect, the present invention provides a method for preparing the plastic welding rod according to the first aspect, the method comprising:

[0018] After the iron powder, PP material and POE elastomer material are mixed to obtain a mixture, the mixture is first subjected to twin-screw granulation and then subjected to single-screw extrusion to obtain the plastic welding rod.

[0019] Preferably, the twin-screw granulation comprises twin-screw extrusion and granulation performed sequentially.

[0020] Preferably, the twin-screw extruder uses a six-outlet die with a diameter of 4 to 8 mm, for example, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, 7 mm, 7.5 mm or 8 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the temperature of the twin-screw extrusion is 170-180°C, for example, it can be 170°C, 171°C, 172°C, 173°C, 174°C, 175°C, 176°C, 177°C, 178°C, 179°C or 180°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0022] Preferably, air cooling is further included between the twin-screw extrusion and granulation.

[0023] Preferably, the granulation comprises automatic cutting granulation.

[0024] Preferably, the die used for the single-screw extrusion is of the one-in-one type, and the diameter of each caliber is 2.0 to 3.0 mm, for example, it can be 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm or 3.0 mm, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, the temperature of the single screw extrusion is 180-190°C, for example, it can be 180°C, 181°C, 182°C, 183°C, 184°C, 185°C, 186°C, 187°C, 188°C, 189°C, or 190°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] Preferably, the preparation method further comprises cooling and winding in sequence after the single-screw extrusion.

[0027] Preferably, the cooling comprises cooling the extruded strip obtained by single-screw extrusion into water.

[0028] Preferably, the winding includes winding the extruded strip after cooling in water into a reel.

[0029] As a preferred technical solution of the preparation method of the present invention, the preparation method comprises:

[0030] (1) mixing iron powder, PP material and POE elastomer material to obtain a mixture;

[0031] (2) using a die with six holes and each having a diameter of 4 to 8 mm, extruding the mixture obtained in step (1) through a twin-screw extruder at 170 to 180° C., automatically cutting and granulating after air cooling, and then extruding through a single-screw extruder at 180 to 190° C. using a die with one hole and each having a diameter of 2.0 to 3.0 mm, to obtain extruded strips;

[0032] (3) Cooling the extruded strip obtained in step (2) in water, and then winding the extruded strip after water cooling into a roll to obtain the plastic welding rod.

[0033] In a third aspect, the present invention provides an application of the plastic welding rod described in the first aspect, wherein the plastic welding rod is used for welding.

[0034] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The plastic welding rod provided by the present invention is composed of iron powder, PP material and POE elastomer material, and can be prepared by extrusion molding through a mold with a diameter of 2.0 to 3.0 mm; in addition, the plastic welding rod has excellent welding effect, a smooth appearance, good flexibility and bendability. DETAILED DESCRIPTION

[0037] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0038] Example 1

[0039] This embodiment provides a plastic welding rod, which is composed of spherical iron powder and / or flaky iron powder, pp material and POE elastomer material; the mass ratio of iron powder, pp material and POE elastomer material in the plastic welding rod is 80:10:10; and the average diameter of the plastic welding rod is 2.5 mm.

[0040] The preparation method of the plastic welding rod is:

[0041] (1) mixing iron powder, PP material and POE elastomer material to obtain a mixture;

[0042] (2) using a die with six openings and each opening having a diameter of 5 mm, extruding the mixture obtained in step (1) through a twin-screw extruder at 175° C., automatically cutting and granulating after air cooling, and then extruding through a single-screw extruder at 185° C. using a die with one opening and each opening having a diameter of 2.5 mm, to obtain extruded strips;

[0043] (3) Cooling the extruded strip obtained in step (2) in water, and then winding the extruded strip after water cooling into a roll to obtain the plastic welding rod.

[0044] Example 2

[0045] This embodiment provides a plastic welding rod, which is the same as that of Embodiment 1 except that the mass ratio of iron powder, PP material and POE elastomer material in the plastic welding rod is 75:15:10.

[0046] Example 3

[0047] This embodiment provides a plastic welding rod, which is composed of spherical iron powder and / or flaky iron powder, pp material and POE elastomer material; the mass ratio of iron powder, pp material and POE elastomer material in the plastic welding rod is 80:10:12; and the average diameter of the plastic welding rod is 2.0 mm.

[0048] The preparation method of the plastic welding rod is:

[0049] (1) mixing iron powder, PP material and POE elastomer material to obtain a mixture;

[0050] (2) using a die with six openings and each opening having a diameter of 4 mm, the mixture obtained in step (1) is subjected to twin-screw extrusion at 170° C., air-cooled, and then automatically cut and granulated, and then subjected to single-screw extrusion at 180° C. using a die with one opening and one opening having a diameter of 2.0 mm, to obtain extruded strips;

[0051] (3) Cooling the extruded strip obtained in step (2) in water, and then winding the extruded strip after water cooling into a roll to obtain the plastic welding rod.

[0052] Example 4

[0053] This embodiment provides a plastic welding rod, which is composed of spherical iron powder and / or flaky iron powder, pp material and POE elastomer material; the mass ratio of iron powder, pp material and POE elastomer material in the plastic welding rod is 70:15:10; and the average diameter of the plastic welding rod is 3.0 mm.

[0054] The preparation method of the plastic welding rod is:

[0055] (1) mixing iron powder, PP material and POE elastomer material to obtain a mixture;

[0056] (2) using a die with six openings and each opening having a diameter of 8 mm, extruding the mixture obtained in step (1) through a twin-screw extruder at 180° C., automatically cutting and granulating after air cooling, and then extruding through a single-screw extruder at 190° C. using a die with one opening and each opening having a diameter of 3.0 mm, to obtain extruded strips;

[0057] (3) Cooling the extruded strip obtained in step (2) in water, and then winding the extruded strip after water cooling into a roll to obtain the plastic welding rod.

[0058] Example 5

[0059] This embodiment provides a plastic welding rod, which is the same as that of Embodiment 1 except that the mass ratio of iron powder, PP material and POE elastomer material in the plastic welding rod is 75:10:15.

[0060] Example 6

[0061] This embodiment provides a plastic welding rod, which is the same as that of Embodiment 1 except that twin-screw extrusion is performed at 195° C. in the preparation method of the plastic welding rod.

[0062] Example 7

[0063] This embodiment provides a plastic welding rod, which is the same as that of Embodiment 1 except that a single-screw extrusion is performed at 165° C. using a one-out-one die in the preparation method of the plastic welding rod.

[0064] Example 8

[0065] This embodiment provides a plastic welding rod, which is the same as that of Embodiment 1 except that a single-screw extrusion is performed at 200° C. using a one-out-one mold in the preparation method of the plastic welding rod.

[0066] Comparative Example 1

[0067] This comparative example provides a plastic welding rod, which is the same as Example 1 except that the mass ratio of iron powder, PP material and POE elastomer material in the plastic welding rod is 75:5:20.

[0068] Comparative Example 2

[0069] This comparative example provides a plastic welding rod, which is the same as Example 1 except that the PP material in the plastic welding rod is omitted, that is, the plastic welding rod only contains iron powder and POE elastomer material in a mass ratio of 80:10.

[0070] Comparative Example 3

[0071] This comparative example provides a plastic welding rod, which is the same as Example 1 except that the mass ratio of iron powder, PP material and POE elastomer material in the plastic welding rod is 75:20:5.

[0072] Comparative Example 4

[0073] This comparative example provides a plastic welding rod, which is the same as Example 1 except that the POE elastomer material in the plastic welding rod is omitted, that is, the plastic welding rod only contains iron powder and PP material in a mass ratio of 80:10.

[0074] The plastic welding rods provided in the above embodiments and comparative examples were used for welding, and the welding quality after welding was tested. The welding quality was classified into firm, relatively firm, easy to fall off and very easy to fall off in order from good to bad. The test results are shown in Table 1.

[0075] The flexibility of the plastic welding rods provided in the above embodiments and comparative examples was tested, and they were divided into excellent, good, general, poor and very poor according to the flexibility from strong to weak. The test results are shown in Table 1.

[0076] The bendability of the plastic welding rods provided in the above embodiments and comparative examples was tested, and the cracking of the obtained plastic welding rods when bent 180° was classified into no cracking, slight cracking, and fracture according to the bendability from strong to weak. The test results are shown in Table 1.

[0077] The smoothness of the appearance of the plastic welding rods provided in the above embodiments and comparative examples was tested, and the smoothness of the appearance of the plastic welding rods was divided into smooth surface and rough surface from good to bad. The test results are shown in Table 1.

[0078] Table 1

[0079] Welding quality Flexibility Bendability Appearance finish Example 1 firm good No cracking Smooth surface Example 2 Strong good No cracking Smooth surface Example 3 firm good No cracking Smooth surface Example 4 Strong good No cracking Smooth surface Example 5 Easy to fall off Excellent No cracking Smooth surface Example 6 Strong Difference fracture Smooth surface Example 7 Strong generally Small cracks Rough surface Example 8 Strong generally fracture Rough surface Comparative Example 1 Unable to weld Excellent No cracking Smooth surface Comparative Example 2 Unable to weld Very bad fracture Smooth surface Comparative Example 3 Easy to fall off Excellent No cracking Smooth surface Comparative Example 4 Very easy to fall off Very bad fracture Smooth surface

[0080] From Table 1, we can get:

[0081] (1) When the plastic welding rods provided in Examples 1 to 4 are used for welding, good welding quality is exhibited, and the plastic welding rods also have good flexibility, strong bendability and a smooth appearance;

[0082] (2) By comparing Example 1 with Example 5, it can be seen that the mass ratio of iron powder, pp material and POE elastomer material in the plastic welding rod of the present invention is (75-80):(10-15):(10-12), which can make the plastic welding rod have better performance. This is because the iron powder material in the welding rod is the welding main body, the pp material has the characteristics of high temperature softening and low temperature hardening, and the POE elastomer has excellent thermoplasticity and toughening. Only when the mass ratio of iron powder, pp material and POE elastomer material meets the range in this application, can the plastic welding rod show better welding quality during welding.

[0083] (3) By comparing Example 1 with Example 6, it can be seen that the twin-screw extrusion in the preparation method of the plastic welding rod of the present invention will affect the performance of the plastic welding rod; when the twin-screw extrusion temperature is 170-180°C, the plastic welding rod has better performance. This is because the melting point of PP material is generally 164-170°C. Granulation at a temperature of 170-180°C ensures that the PP material can melt while avoiding brittleness of the material caused by excessive temperature.

[0084] (4) By comparing Example 1 with Examples 7 and 8, it can be seen that the temperature of single-screw extrusion in the preparation method of the plastic welding rod of the present invention will affect the performance of the plastic welding rod; when the temperature of single-screw extrusion is 180-190°C, the plastic welding rod has better performance, because in this temperature range, the best extrusion effect can be guaranteed; when the temperature is low, the granular material in the extruder screw cannot be melted, resulting in abnormal processing, and the welding rod cannot be extruded or has a rough surface; when the temperature is too high, it will cause the material to become brittle, and the welding rod will have poor toughness and breakage after extrusion.

[0085] (5) By comparing Example 1 with Comparative Examples 1 to 4, it can be seen that the plastic welding rod provided by the present invention is composed of iron powder, pp material and POE elastomer material, and the mass ratio of the iron powder, pp material and POE elastomer material is further limited, and can be prepared by extrusion molding through a mold with a diameter of 2.0 to 3.0 mm; in addition, the plastic welding rod also has excellent welding effect, a smooth appearance, good flexibility and bendability.

[0086] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention are within the protection scope and disclosure scope of the present invention.

Claims

1. A plastic welding rod, characterized in that: The plastic welding rod is composed of iron powder, pp material and POE elastomer material; the mass ratio of the iron powder, pp material and POE elastomer material in the plastic welding rod is (70-80):(10-15):(10-15).

2. The plastic welding rod according to claim 1, characterized in that: The mass ratio of iron powder, PP material and POE elastomer material in the plastic welding rod is (75-80):(10-15):(10-12).

3. The plastic welding rod according to claim 1 or 2, characterized in that: The iron powder includes spherical iron powder and / or flake iron powder.

4. The plastic welding rod according to any one of claims 1 to 3, characterized in that: The average diameter of the plastic welding rod is 2.0-3.0 mm.

5. A method for preparing the plastic welding rod according to any one of claims 1 to 4, characterized in that: The preparation method comprises: After the iron powder, PP material and POE elastomer material are mixed to obtain a mixture, the mixture is first subjected to twin-screw granulation and then subjected to single-screw extrusion to obtain the plastic welding rod.

6. The preparation method according to claim 5, characterized in that: The twin-screw granulation comprises twin-screw extrusion and granulation performed sequentially; Preferably, the twin-screw extruder adopts a six-outlet die, and the diameter of each caliber is 4 to 8 mm; Preferably, the twin-screw extrusion temperature is 170-180°C; Preferably, air cooling is further included between the twin-screw extrusion and granulation; Preferably, the granulation comprises automatic cutting granulation.

7. The preparation method according to claim 5 or 6, characterized in that: The die used for the single screw extrusion is a one-out-one type, and the diameter of each caliber is 2.0-3.0 mm; Preferably, the temperature of the single screw extrusion is 180-190°C.

8. The preparation method according to any one of claims 5 to 7, characterized in that: The preparation method further comprises cooling and winding in sequence after the single screw extrusion; Preferably, the cooling comprises cooling the extruded strip obtained by single screw extrusion into water; Preferably, the winding includes winding the extruded strip after cooling in water into a reel.

9. The preparation method according to any one of claims 5 to 8, characterized in that: The preparation method comprises: (1) mixing iron powder, PP material and POE elastomer material to obtain a mixture; (2) using a die with six holes and each having a diameter of 4 to 8 mm, extruding the mixture obtained in step (1) through a twin-screw extruder at 170 to 180° C., automatically cutting and granulating after air cooling, and then extruding through a single-screw extruder at 180 to 190° C. using a die with one hole and each having a diameter of 2.0 to 3.0 mm, to obtain extruded strips; (3) Cooling the extruded strip obtained in step (2) in water, and then winding the extruded strip after water cooling into a roll to obtain the plastic welding rod.

10. An application of the plastic welding rod according to any one of claims 1 to 4, characterized in that: The plastic welding rod is used for welding.