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KR-20260065112-A - PELLET DERIVED FROM RECYCLED ASEPTIC PACKS

KR20260065112AKR 20260065112 AKR20260065112 AKR 20260065112AKR-20260065112-A

Abstract

The present invention relates to a pellet that can be blended with various polymers to control the physical properties of a product when manufacturing a plastic molded article, and is characterized by comprising 100 parts by weight of a mixed resin comprising a composition containing 65 to 80 parts by weight of recycled polyethylene, 15 to 30 parts by weight of recycled aluminum, and 5 to 10 parts by weight of recycled pulp fiber, and a molding resin in a weight ratio of 5:95 to 50:50, and 10 to 20 parts by weight of a flexural strength improver and 3 to 10 parts by weight of an impact strength improver.

Inventors

  • 문병철
  • 이민우
  • 서동준
  • 오준균

Assignees

  • 한솔제지 주식회사

Dates

Publication Date
20260508
Application Date
20241031

Claims (8)

  1. A pellet comprising 100 parts by weight of a mixed resin comprising a composition comprising 65 to 80 wt% recycled polyethylene, 15 to 30 wt% recycled aluminum, and 5 to 10 wt% recycled pulp fiber, and a molding resin in a weight ratio of 5:95 to 50:50, 10 to 20 parts by weight of a flexural strength improver, and 3 to 10 parts by weight of an impact strength improver.
  2. In claim 1, the flexural strength improving agent is a pellet selected from inorganic fillers, silicone-based additives, and elastomers.
  3. In claim 1, the impact strength improver is a pellet selected from polyolefin elastomers and rubber-based additives.
  4. In claim 1, the impact strength improver is a pellet of a polyolefin elastomer having a melt index (190℃ / 2.16 kg, ASTM D1238) of 3 to 10 g/10 min.
  5. A pellet according to claim 1, further comprising 1 to 5 parts by weight of a flowability improver per 100 parts by weight of the mixed resin.
  6. In claim 1, the flowability improver is a pellet selected from stearate-based, wax-based, magnesium and zinc oxide, and synthetic hydrotalcite.
  7. In claim 1, the molding resin is one or more pellets selected from acryl butadiene stadiene (ABS) resin, acrylic resin, high-density polyethylene (HDPE), low-density polyethylene (LDPE), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polypropylene (PP), and polystyrene (PS).
  8. A molded article manufactured by melt extrusion or injection molding of a pellet according to any one of claims 1 to 7.

Description

Pellet derived from recycled aseptic packs The present invention relates to sterile pack-derived pellets that can be used to extrude or inject other useful products, and a method for manufacturing the same. As the global economy has continuously developed over the past few years, demand for beverages, milk, and other products in various countries has been steadily increasing. Consequently, the use of aseptic cartons (commonly known as 'Tetra Pak' in distribution) used for beverages or milk has also increased, placing pressure on environmental protection and resource utilization. (On October 8, 2024, during the 2024 National Audit of the Environment and Labor Committee, Representative Park Hong-bae of the Democratic Party of Korea urged Environment Minister Kim Wan-sup to share the current status of aseptic carton recycling and to make improvements.) Aseptic packaging is a multilayer polymer-coated cardboard containing an aluminum foil layer, typically containing approximately 75% by weight of cardboard, 20% by weight of plastic, and 5% by weight of aluminum. The separation and recycling of cardboard fibers recovered from aseptic packaging are routinely carried out, and markets for processing them into industrial and consumer products already exist. However, the mixture of polymer and aluminum known as "polyal" remaining after separating the fibers is difficult to separate economically, resulting in a lack of commercial application for this material and a low recycling rate (1.4% compared to the mandatory recycling rate of 10.9% in 2023). Polyal is known to have higher thermal oxidation stability, crystallinity, and tensile strength than the corresponding pure olefin polymer, but lower impact resistance. WO2023-148259 A1 introduces that the polyal contains 85 wt% or more of polyethylene, 0.5 to 18 wt% (e.g., 2 to 15 wt%) of aluminum, and 0 to 2 wt% of other components such as cellulose, with the amount of aluminum generally being 2 to 5 wt%. It is known that additional virgin LDPE-containing polyal is processed into granular form for the utilization of polyal, and used to manufacture injection-molded products such as hangers, pens, crates, benches, and flowerpots. An example of the commercial use of polyal is the EcoAllene product sold by Ecoplasteam SpA. This product contains polyal blends with polypropylene or high-density polyethylene (HDPE). The EcoAllene product BA35PO5H contains polyal + 35 wt% polypropylene, 5 wt% HDPE, and 5 wt% additives, and has a density of 988 kg/ m³ , a melt index ME of 7.74 g/10 min, an Izod impact resistance of 14 kJ/ m² (ISO 180), and a flexural modulus of 905 MPa (ISO 178). EcoAllene products are known to be suitable for various molded products (WO2023-148259 A1). Although there are various attempts to utilize polyal, the development of diverse products capable of increasing its utility is still necessary. The present invention provides pellets derived from sterile packs that can be used together when extruding or injecting various products, and a method for manufacturing the same. The pellets according to the present invention use waste sterile packs recovered through the collection of recyclable materials as raw materials. The method for manufacturing pellets of the present invention comprises the following steps. First, waste sterile packs are fed into a dissociation facility to separate them into pulp fibers and residues. The dissociation process consists of first feeding waste sterile pack raw materials provided by a recycling collection company into a specialized pulp dissociation agitator called a pulper at a certain ratio along with water, and then applying a strong shear force to separate the pulp and polyal. Generally, the sterile pack consists of about 75% by weight of pulp fiber, about 20% by weight of polymer (mainly polyethylene), about 5% by weight of aluminum, and the remainder of other components. The amount of sterile pack fed into the dissociation equipment is adjusted so that the concentration is in the range of 3 to 10% by weight, and the dissociation time may take 10 to 30 minutes. The dissociation equipment has a perforated mesh at the bottom, through which separated pulp fibers are discharged, and residues are caught and placed on the perforated mesh. After undergoing a foreign matter removal process, the discharged pulp fibers can be used as raw materials for manufacturing white cardboard (some products such as dairy product packaging boxes). The residue placed on the perforated mesh is discharged after a washing process with a moisture content of 50 to 70 weight percent, and then subjected to a compression dewatering process to reduce the moisture content to 30 to 40 weight percent. Drying efficiency can be increased by undergoing the compression dewatering process. The residue from the compression dehydration is subjected to a drying process so that the moisture content is less than 10% by weight. In the case of natural drying, it can be processed