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KR-102962819-B1 - A method for preparing multi-functional blending film

KR102962819B1KR 102962819 B1KR102962819 B1KR 102962819B1KR-102962819-B1

Abstract

The present invention relates to a novel manufacturing method for producing a high-performance blending film and a high-performance blending film produced according to the novel manufacturing method. The manufacturing process of the present invention provides various advantages in the manufacturing process, such as reducing initial purging defects, maintaining a stable bubble shape, maintaining stable mechanical properties (tensile strength, elongation, tear strength) on the recycled film, and enabling stable process production and stable property management due to the smooth flow of raw materials on the raw material conveying device.

Inventors

  • 김미진
  • 박철민
  • 심희준

Assignees

  • 주식회사 대인

Dates

Publication Date
20260512
Application Date
20231211

Claims (10)

  1. A method for manufacturing a recycled polyethylene high-performance film that meets GR certification standards, Step 1: Preparing a first resin mixture by introducing a primary raw material mixture, in which recycled polyethylene (PE) resin meeting GR certification standards and a new material polyethylene (PE)-based resin are blended at a weight blending ratio (w/w) of 21-70:30-79 (%), into a stainless steel container and mixing the primary resin mixtures together; Step 2, in which the first resin mixture of Step 1 is placed into a stirrer and stirring (kneader) is performed at a stirring speed of 20 to 80 stirring cycles/min in a cylinder temperature range of 40 to 100℃; A third step in which a specially manufactured impeller rotates at high speed while introducing and stirring a secondary additive mixture containing a slip agent and a dispersant to uniformly mix and fuse the secondary mixture (mixer) to obtain a regenerated mixed resin with added additives; Step 4, obtaining a recycled resin extruder by extruding the recycled mixed resin into which the additives of Step 3 are introduced in an extruder at a prime mover speed of 500 RPM under conditions where the cylinder temperature (°C) is in the range of 110 to 162°C, the screen temperature (S°C) is in the range of 150 to 160°C, the adapter temperature (A°C) is in the range of 135 to 165°C, and the die temperature (D°C) is in the range of 140 to 170°C; A fifth step of cooling the recycled resin extruded product of the above fourth step in a cooler; Step 6, cutting the cooled extruded material from Step 5 with a cutter to obtain a cut; Step 7, obtaining a dried product by subjecting the cut product of Step 6 above to a drying step in a dryer; It includes an 8th step of completing the drying process of the above 7th step and packaging the final product using a packaging machine utilizing aluminum packaging/moisture barrier (PE Aluminum Packaging), and A manufacturing process for producing a high-performance recycled polyethylene film, characterized in that, in the third step above, the secondary mixture is mixed in a relative mixing weight ratio (w/w/w/w) of recycled resin: new material: slip agent: dispersant of 100-500: 100-440: 5-35: 1-1.5, and mixing and blending are performed under conditions of a mixing time of 40 minutes to 120 minutes.
  2. In Article 1, A manufacturing process characterized in that the above polyethylene (PE) is at least one selected from high-density polyethylene (HDPE), low-density polyethylene (LDPE), medium-density polyethylene (MDPE), linear low-density polyethylene (LLDPE), and ethylene vinyl copolymer (EVA).
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  4. In Article 1, The dispersant of the third step above is an additive added for compatibility between the resins used, selected from carboxylated polyethylene, phthalic acid, stearic acid, monocarbonate, or derivatives thereof, in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the total resin composition. A manufacturing process characterized by use within a range.
  5. In Article 1, A manufacturing process characterized in that the slip agent (anti-blocking agent) of the third step is selected from alkali metal salts of fatty acids, alkaline earth salts of fatty acids, transition metal salts of fatty acids, fatty acid amides, or any combination thereof, and is used in a range of 0.1 to 20 parts by weight based on 100 parts by weight of the total resin composition.
  6. In Article 1, A manufacturing process characterized by performing, in the above-mentioned fourth step, an EC (Electronic chemical) reaction and/or a PC (Polygonum Change) reaction as an additional process, wherein the residence time in the EC (Electronic chemical) reactor is 1 hour to 10 hours, and the process includes a raw material input step, a heating step, an initial reaction step, a reaction progress step, a Ripening atmosphere, a catalyst input step, and a transfer step.
  7. In Article 1, A manufacturing process characterized by performing, in the above-mentioned fourth step, a process including, as an additional process, oligomer transfer, heating, a low vacuum reaction step, a high vacuum reaction step, a high viscosity oligo change reaction step, a mixing step after the reaction is completed, a compounding step, a dehumidification step, and a packaging step while maintaining a residence time in a PC (Ploe Change) reactor for 1 to 10 hours.
  8. In Article 1, A manufacturing process characterized by comprising, in the above 4th step, (1) setting the temperature of the die and cylinder, (2) checking the temperature change of the die and cylinder, (3) a die temperature setting step, (4) a die purging step, (5) a bubble shape correction step, (6) a bubble shape correction step 1, (7) a bubble shape correction step 2, (8) a winder winding execution step, and (9) a finished product production step.
  9. A high-performance blending film manufactured according to the manufacturing process described in Clause 1.
  10. The high-performance blending film described in claim 9 is a high-performance blending film exhibiting physical properties such as a melt index (M.I) in the range of 0.8 to 3.0 (g/10min); a density (g/cc) in the range of 0.900 to 0.950 (g/cc); a Vicat softening point (°C) in the range of 100 to 105 (°C); a tensile strength (N/cm²) in the range of 120 to 375 (N/cm²); and an elongation (%) in the range of 530 to 985 (%).

Description

A method for preparing a multi-functional blending film The present invention relates to a method for manufacturing a high-performance blending film. Plastics have advantages such as being easy to mold and lightweight, so plastics such as PET (polyethylene terephthalate), PS (polystyrene), PP (polypropylene), PE (polyethylene), ABS (acrylonitrile-butadiene-styrene copolymer), and SAN (styrene acrylonitrile copolymer) are used in various fields. As the amount of plastic used increases, the amount of plastic discarded also rises, making the recycling of waste plastics, such as used beverage containers and cosmetic containers, a serious challenge. To recycle discarded plastics, they undergo processes such as washing, crushing, centrifugation, melting, and drying. Research is needed to control these processes so that the properties of the plastic are not altered or deteriorated. In addition, research is needed to optimize recycled plastics produced through the recycling process so that they possess the physical properties required for the products to which they are applied. (Korean Published Patent No. 10-2015-0107239) Meanwhile, methods for recycling waste plastics (resins) include mechanical recycling, chemical recycling, and thermal recycling. Mechanical recycling is a method in which collected waste plastics are crushed and sorted to separate them by type, then melted and pelletized, and mixed with virgin material in a specific ratio to manufacture resin products. Chemical recycling is a method in which specific polymers are extracted from waste plastics using various chemical means, or pure monomers are recovered and repolymerized. Thermal recycling is a method in which waste plastics are incinerated to recover thermal energy. (Korean Published Patent No. 10-2023-0138359) Waste plastics, which account for approximately 70% of marine pollution, have recently emerged as a serious social issue. Consequently, countries are regulating the use of single-use plastics while simultaneously promoting the reuse of waste plastics. Currently, waste plastics are collected, crushed, and cleaned, then melt-extruded to form re-pellets, which are then used as raw materials for reuse. However, it is very difficult to provide high-quality products due to impurities within the waste plastics. Therefore, there is an urgent need for research to produce high-quality plastic products from waste plastics (Korean Patent Publication No. 10-2021-0009844). Various additives, such as stabilizers, slip agents, flame retardants, and lubricants, are used in plastics to exhibit physical properties suitable for their intended purpose. As environmental and human health hazards have become a global concern, regulations have been established regarding previously used hazardous additives. While mechanical recycling methods such as melting and extrusion are used to recycle plastics easily and quickly, this process makes it difficult to remove the additives contained within the plastic. In addition to the mechanical recycling method described above, a process was applied to remove additives from plastic using a solvent extraction method and obtain recycled plastic. In the stirring process typically performed in the solvent extraction method, if stirring is not sufficiently carried out, additives cannot be effectively removed from the waste plastic. (Korean Published Patent No. 10-2023-0040545) Recycled polyolefins are derived from the stream of post-consumer waste (PCW) materials that undergo various separation steps from other polymers such as PVC, PET, or PS. In particular, when processing material flows from post-consumed waste (PCW), one of the major problems in polyolefin recycling is that it is difficult to quantitatively separate polyethylene (PE) into polypropylene (PP) and vice versa. Therefore, even though they are named recycled PE (rPE) or recycled PP (rPP), commercially available products from PCW resources have been found to be mixtures of PP and PE, with trace components reaching up to less than 50 wt%. This fact leads to the conclusion that, in relation to the presence of additives and trace components in the recycled material that may not be entirely suitable for the intended application, the recycled PP/PE blends may exhibit defects such as deterioration of mechanical, optical, and aesthetic properties and poor compatibility between the main polymer phases during remolding. Consequently, low reliability of articles resulting from the use of r-PP or r-PE is recognized due to the low performance of the compositions derived from these blends. Consequently, the use of recycled materials in applications requiring high performance levels is strongly hindered and is limited to low-cost applications where there is no demand (Korean Published Patent No. 10-2023-0078817). Prior art regarding methods for manufacturing recycled plastics includes: Korean Patent Publication No. 10-2008-0056470, regarding the technology for “heat shrink film us