TIRE GRADE HIGH TENACITY AND MODULUS RECYCLE NYLON 6.6 YARN AND PRODUCTION METHOD THEREOF

Abstract

A tire grade oiled and non-oiled nylon 6.6 drawn and undrawn scrap yarns is converted to a recycled nylon 6.6 pellet. The recycled nylon 6.6 pellet is used with virgin nylon 6.6 pellet in a different ratio to produce tire grade recycled nylon 6.6 yarn.

Claims

1. A tire grade nylon 6.6 mono- and/or multi filament yarn comprising: at least 10% recycled nylon 6.6 pellet, wherein the nylon 6.6 filament yarn has at least 8.0 gpd tenacity according to ASTM-D 885.

2. The tire grade filament yarn according to claim 1 further comprising 20% recycled nylon 6.6.

3. The tire grade filament yarn according to claim 1, further comprising at least 1.25 gpd 4% SASE according to ASTM-D 885.

4. A manufacturing method of a tire grade filament yarn according to claim 1 further comprising the steps of: preparing recycled nylon 6.6 pellet by cutting of tire grade oiled and/or non-oiled drawn and/or undrawn nylon 6.6 fiber scraps including mono- and/or multi-filament yarn into 3-5 cm to get nylon 6.6 chopped fibers, feeding to an extruder that has minimum 250 C. and maximum 290 C. in 6 zones to get the molten nylon 6.6 polymer from the scrap yarns, cooling of strands, cutting in a size between 300 to 500 pellet in 10 gram which is shaped as a pellet form, wherein the recycled nylon 6.6 pellet has a maximum 0.05% finish oil in it, preparing a virgin nylon 6.6 pellet mixing the virgin nylon 6.6 pellet and the recycled nylon 6.6 pellet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present disclosure can be more understood by reading the following detailed description of the drawings as follows;

[0012] FIG. 1: Standard yarn bobbins (1.8) (tire grade nylon 6.6 yarn bobbins) production steps consist of virgin nylon 6.6 pellets (virgin nylon 6.6 pellets flake) (1.1) fed to silos, first nylon 6.6 pellets purged (1.2) and then they have solid state polymerization process (1.3), polymerized nylon 6.6 pellets converted to molten nylon 6.6 polymer (1.4), molten nylon 6.6 polymer go through a die to get the round filament shape (1.5), nylon 6.6 polymer filament cooled (1.6), nylon 6.6 filament have some process steps to get the desire end properties (1.7), at the end tire grade nylon 6.6 yarn bobbins (1.8) were produced.

[0013] FIG. 2: The method for recycling nylon 6.6 pellets includes the steps of collecting oiled and non-oiled nylon 6.6 drawn and undrawn yarn scraps during yarn production (2.1); chopping nylon 6.6 yarn scraps into short strands (2.2); transporting the chopped nylon 6.6 yarn scraps to the compressing unit (2.3); feeding the compressed nylon 6.6 scraps into the extruder (2.4); melting of nylon 6.6 scraps (2.5); vacuuming of oil from molten polymer (2.6); to form nylon 6.6 strands (2.7); cooling the nylon 6.6 strands in the water bath (2.8); drying nylon 6.6 strands coming out of the water bath (2.9); pelletizing of nylon 6.6 strands (2.10); collecting recycled nylon 6.6 pellets (2.11) and packaging of recycled nylon 6.6 pellets (2.12).

[0014] FIG. 3: This figure is very similar to FIG. 1. Only difference is that at the beginning of the process, virgin (3.1) and recycled (3.2) flakes are mixed homogeneous with a blending system in a certain proportion. [0015] Tire grade yarn: Nylon 6.6 yarn that have minimum 8,0 gpd (grams per denier) tenacity and 100 to 5000 dtex density level. [0016] 4% SASE: Stress at 4% elongation (gpd) [0017] Tenacity: strength of yarn (gram)/density of yarn (denier) (gpd) Virgin nylon 6.6 pellet: Raw nylon 6.6 pellet [0018] Recycled nylon 6.6 pellet: nylon 6.6 pellet that is form from scrap material [0019] Tire grade nylon 6.6 yarn: nylon 6.6 yarn used in cord in tires [0020] Oiled and non-oiled nylon 6.6 drawn and undrawn yarn scraps: yarn scraps that are processed and unprocessed [0021] Nylon 6.6 strands: molten polymer after the extruder (like a spaghetti)

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0022] The invention relates to a tire grade nylon 6.6 mono- and/or multi filament yarn comprising at least 10% recycled nylon 6.6, preferably 20% recycled nylon 6.6 wherein the said nylon 6.6 mono or multi filament yarn has at least 8.0 gpd tenacity according to ASTM-D 885.

[0023] ASTM-D 885 is a standard test methods for tire cords, tire cord fabrics, and industrial filament yarns made from man-made organic-base fibers.

[0024] The tire grade nylon 6.6 mono- and/or multi filament yarn has at least 1.25 gpd 4% SASE according to ASTM-D 885.

[0025] A manufacturing method of a tire grade nylon 6.6 mono- and/or multi filament yarn comprises the steps of: [0026] a) Recycled nylon 6.6 pellet production, [0027] Cutting of tire grade oiled and/or non-oiled drawn and/or undrawn nylon 6.6 fiber scraps including mono- and/or multi-filament yarn into 3 cm to 5 cm to get nylon 6.6 chopped fibers, [0028] Feeding to extruder that has minimum 250 C. and maximum 290 C. in 6 zones to get the molten nylon 6.6 polymer from the scrap yarns, [0029] Cooling of strands, [0030] Cutting in a size between 300 to 500 pellet in 10 gram which is shaped as a pellet form, wherein recycled nylon 6.6 pellet that has maximum 0.05% finish oil in it, [0031] b) Virgin nylon 6.6 pellet production, [0032] c) Mixture of virgin and recycled nylon 6.6 pellets in minimum 20% recycle pellet ratio to produce tire grade recycled nylon 6.6 yarn.

[0033] At the beginning of the process, tire grade oiled and/or non-oiled drawn and/or undrawn nylon 6.6 fiber scraps including filament yarn is cut ranges from 3 cm to 5 cm to get nylon 6.6 chopped fibers. Chopped fibers feed to extruder to get the molten polymer from the scrap yarns. Molten polymer shaped to molten fiber in a certain diameter and cool in a water bath. After cooling of the fiber polymer, they cut in a certain size that called strand pelletizing system in the literature.

[0034] Vacuum is active during the tire grade recycled pellet production to remove the finish oil in the polymer matrix coming from the scrap oiled yarn production process. It is very critical process for the production since the high finish oil level caused in low production yields and high break levels in spinning. Main aim is to minimize the finish oil level in the recycled pellet.

[0035] Since the tire grade recycled pellet and virgin pellet mixed during the production, homogeneous mixing is another critical parameter in the preparation phase of the solid state polymerization. Pellet size of the two pellet grade need to be as much as close each other to prevent separation in the silos. So that, granulometry of the tire grade recycled pellet were improved for the tire grade recycled yarn production.

[0036] Tire grade recycled amount in the yarn depends on the customer expectations and minimum specification requirements. However according to Global Recycling Certification system, minimum requirement of the recycled amount is 20% in the end product. So that according to this regulation, studies were focused to 20% recycled material in the tire grade yarn. Recycled pellet and virgin pellet was mixed and fed to silo for conditioning. Solid state polymerization was adjusted according to new mixtured raw material to get the same RV level at the end of the conditioner exit.