Screw assembly for eliminating melt index fluctuation of polypropylene

Abstract

The utility model discloses a screw assembly for eliminating melt index fluctuation of polypropylene, and relates to the technical field of high polymer material processing. According to the screw assembly capable of eliminating the fluctuation of the polypropylene melt index, different kneading blocks and conveying thread elements are arranged, so that the mixing uniformity of polypropylene molten resin is improved, the fluctuation of the polypropylene melt index is eliminated, and the stability of product quality is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of polymer material processing, in particular to a screw assembly for eliminating fluctuations in the melt index of polypropylene. Background Art

[0002] Polypropylene is a thermoplastic synthetic resin with excellent performance. It primarily comes in three product categories: homopolymer, copolymer, and impact-resistant. It is widely used in injection molded parts, pipes, films, and fibers. The main production processes include liquid-phase bulk, liquid-phase bulk + vapor-phase combined, and vapor-phase processes. Polypropylene is widely used in the production of fiber products such as clothing and blankets, medical devices, automobiles, bicycles, parts, pipelines, chemical containers, and food and pharmaceutical packaging. However, existing screw assemblies used for polypropylene extrusion can cause uneven mixing, leading to fluctuations in the melt index and reduced product quality. Utility Model Content

[0003] In view of the shortcomings of the existing technology, the present invention provides a screw assembly that eliminates the fluctuation of the polypropylene melt index, so as to solve the problems raised in the above background technology:

[0004] When the existing screw assembly is used to process and extrude polypropylene, uneven mixing of the polypropylene will occur, resulting in fluctuations in the melt index and a decrease in product quality.

[0005] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0006] A screw assembly for eliminating polypropylene melt index fluctuations includes a screw assembly main body, the screw assembly main body including two groups of screws with identical structures and meshing with each other, the screw assembly main body including, in sequence from a first end to a second end, a conveying section, a melting section, a venting section, and a metering section, the conveying section, the melting section, the venting section, and the metering section all being screw structures, the conveying section being provided with a plurality of threaded elements, the threaded elements including a plurality of forward conveying threaded elements and a plurality of reverse conveying threaded elements arranged along the flow direction of the polypropylene, the melting section being provided with a plurality of kneading elements, the kneading elements including a plurality of forward kneading blocks and a plurality of reverse kneading blocks arranged along the flow direction of the polypropylene.

[0007] Preferably, the conveying section is responsible for conveying polypropylene.

[0008] Preferably, the melting section is responsible for melting the polypropylene.

[0009] Preferably, the exhaust section is used to discharge moisture and small molecular substances.

[0010] Preferably, the metering section is responsible for uniform mixing of the polypropylene.

[0011] The utility model provides a screw assembly that eliminates fluctuations in the melt index of polypropylene. Compared with the prior art, it has the following beneficial effects:

[0012] The screw assembly for eliminating polypropylene melt index fluctuation improves the mixing uniformity of polypropylene molten resin by arranging different kneading blocks and conveying screw elements, eliminates the fluctuation of polypropylene melt index, and ensures the stability of product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the internal structure of the utility model;

[0014] Figure 2 It is a schematic diagram of the three-dimensional structure of the utility model.

[0015] In the figure: 1. Conveying section; 2. Melting section; 3. Exhaust section; 4. Metering section; 5. Screw assembly body. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0017] See also Figure 1-2 The utility model provides a technical solution: a screw combination for eliminating fluctuations in the melt index of polypropylene, comprising a screw combination main body 5, the screw combination main body 5 comprising two groups of mutually meshing screws with the same structure, the screw combination main body 5 comprising, in sequence from the first end to the second end, a conveying section 1, a melting section 2, an exhaust section 3 and a metering section 4, the conveying section 1, the melting section 2, the exhaust section 3 and the metering section 4 are all screw structures, the conveying section 1 is provided with a plurality of threaded elements, the threaded elements comprising a plurality of forward conveying threaded elements and reverse conveying threaded elements arranged along the flow direction of polypropylene, the melting section 2 is provided with a plurality of kneading elements, the kneading elements comprising a plurality of forward kneading blocks and reverse kneading blocks arranged along the flow direction of polypropylene, the staggered angle is increased, the transmission capacity is reduced, the residence time of polypropylene in the extruder is prolonged, the mixing uniformity is improved, the fluctuations in the melt index of polypropylene are eliminated, and the stability of product quality is ensured.

[0018] Furthermore, the conveying section 1 is responsible for conveying polypropylene and sending the polypropylene into other structures for processing.

[0019] Furthermore, the melting section 2 is responsible for melting the polypropylene. The melting section 2 is located in a high-temperature heating environment to ensure the melting effect of the polypropylene.

[0020] Furthermore, the exhaust section 3 is used to discharge moisture and small molecular substances, and remove water vapor and other volatile impurities in the polypropylene.

[0021] Furthermore, the metering section 4 is responsible for uniform mixing of the polypropylene to ensure that all the polypropylene is melted.

[0022] During use, the conveying section 1 conveys the polypropylene, the melting section 2 melts the object, and the kneading block extrude and shears the polypropylene, thereby extending the residence time of the polypropylene, improving the mixing uniformity of the polypropylene molten resin, eliminating the fluctuation of the polypropylene melt index, and ensuring the stability of product quality. The exhaust section 3 removes water vapor and other volatile substances in the polypropylene, and the metering section 4 ensures that the polypropylene is mixed evenly to ensure that all the polypropylene is melted. By setting different kneading blocks and conveying screw elements, the mixing uniformity of the polypropylene molten resin is improved, the fluctuation of the polypropylene melt index is eliminated, and the stability of product quality is guaranteed.

[0023] Meanwhile, the contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0024] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include," "comprise," or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations. The phrase "includes an element defined by..." does not exclude the presence of other identical elements in the process, method, article, or device that includes the element.

[0025] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A screw assembly for eliminating polypropylene melt index fluctuations, comprising a screw assembly body (5), characterized in that: The screw assembly body (5) comprises two groups of mutually meshing screws of the same structure. The screw assembly body (5) comprises, in order from the first end to the second end, a conveying section (1), a melting section (2), an exhaust section (3) and a metering section (4). The conveying section (1), the melting section (2), the exhaust section (3) and the metering section (4) are all screw structures. The conveying section (1) is provided with a plurality of threaded elements, which comprise a plurality of forward conveying threaded elements and a plurality of reverse conveying threaded elements arranged along the flow direction of the polypropylene. The melting section (2) is provided with a plurality of kneading elements, which comprise a plurality of forward kneading blocks and a plurality of reverse kneading blocks arranged along the flow direction of the polypropylene.

2. A screw assembly for eliminating polypropylene melt index fluctuation according to claim 1, characterized in that: The conveying section (1) is responsible for conveying polypropylene.

3. The screw assembly for eliminating polypropylene melt index fluctuation according to claim 1, characterized in that: The melting section (2) is responsible for melting the polypropylene.

4. The screw assembly for eliminating polypropylene melt index fluctuation according to claim 1, characterized in that: The exhaust section (3) is used to discharge moisture and small molecular substances.

5. The screw assembly for eliminating polypropylene melt index fluctuation according to claim 1, characterized in that: The metering section (4) is responsible for uniform mixing of the polypropylene.

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