Preparation method of carbon fiber reinforced nylon composite micro-powder for selective laser sintering

Abstract

The present invention discloses a preparation method of carbon fiber reinforced nylon composite micro-powder for selective laser sintering. The method comprises: carrying out surface pre-treatment on carbon fiber powder, adding the pre-treated carbon fiber powder and nylon particles into a polymer good solvent containing a dispersing agent, carrying out heating stirring to completely dissolve the polymer, adding a poor solvent of nylon to make the nylon gradually crystallize by adopting the carbon fibers as the crystal nucleus and be coated on the carbon fiber surface, carrying out suction filtration, drying, screening, and adding other auxiliary agents to obtain the carbon fiber reinforced nylon composite micro-powder for selective laser sintering. Compared to the method in the prior art, the method of the present invention has characteristics of no requirement of high-temperature and high-pressure equipment, simple process, economy, effectiveness, environmental protection, and easy performing; and the sintering performance of the prepared material is excellent, the carbon fiber content in the material is controllable, and the mechanical property of the obtained SLS molded member is substantially improved compared to the SLS molded member of the matrix resin material.

Description

technical field

[0001] The invention relates to the technical field of selective laser sintering materials. More specifically, it relates to a preparation method of carbon fiber reinforced nylon composite micropowder for selective laser sintering. Background technique

[0002] Selective laser sintering (SLS) is an important technology of 3D printing-additive manufacturing. The computer controls the infrared laser beam, scans and sinters the solid powder layer by layer at a certain speed and energy density, accumulates layers, and finally forms a shaped part. Material performance is a key link in the development of SLS technology, which directly affects the forming speed, precision and physical and chemical properties of sintered samples. Polymer powders represented by nylon 12 and their modified materials have the advantages of low water absorption, low melting point, low density, low shrinkage, heat resistance, and easy molding. source material. However, the strength an...

Examples

Embodiment 1

[0038] (1) Extract 1.5 kg of commercially available carbon fiber powder with acetone in a Soxhlet extractor for 48 h, add 1.0 L of nitric acid with a concentration of 14 mol / L after vacuum drying, and oxidize under reflux for 5 h. Dilute with distilled water, vacuum filter, wash until neutral, dry, and pass through a 300-mesh sieve.

[0039] (2) Add 1kg of carbon fiber powder treated in step (1), 3kg of nylon 12 pellets, and 2kg of polyvinylpyrrolidone into 15L of formic acid, heat and stir at 80°C for 2 hours to fully dissolve the nylon 12 pellets.

[0040] (3) While vigorously stirring, add 10 L of absolute ethanol to step (2), and precipitate out after standing still. After suction filtration, washing with ethanol, and drying, sieve with a 200-mesh sieve.

[0041](4) Take step (3) gained carbon fiber-nylon powder 4kg, and flow aid nano silicon dioxide 20g, antioxidant 2,2'-methylene bis-(4-methyl-6-tert-butylphenol ) 10 g, stirred and mixed for 1 h in a vertical mixer to ...

Embodiment 2

[0043] (1) Commercially available 1.5kg carbon fiber powder was extracted with acetone in a Soxhlet extractor for 48 hours, vacuum-dried, added to a toluene solution to stir and disperse, added an ethanol solution of silane coupling agent KH550, ventilated with nitrogen, heated to reflux for 1 hour, and vacuumed Filter, wash, dry, and pass through a 300-mesh sieve.

[0044] (2) Add 1kg of carbon fiber powder treated in step (1), 3kg of nylon 12 pellets, and 2kg of polyvinylpyrrolidone into 15L of formic acid, heat and stir at 80°C for 2 hours to fully dissolve the nylon 12 pellets.

[0045] (3) While vigorously stirring, add 10 L of absolute ethanol to step (2), and precipitate out after standing still. After suction filtration, washing with ethanol, and drying, sieve with a 200-mesh sieve.

[0046] (4) Take step (3) gained carbon fiber-nylon powder 4kg, and flow aid nano silicon dioxide 20g, antioxidant 2,2'-methylene bis-(4-methyl-6-tert-butylphenol ) 10 g, stirred and mix...

Embodiment 3

[0048] (1) Commercially available 1.5kg carbon fiber powder was extracted with acetone for 48 hours in a Soxhlet extractor, dried in a vacuum, added to 14 mol / L nitric acid, heated to reflux for 5 hours for oxidation. Dilute with distilled water, vacuum filter, wash until neutral, dry, and pass through a 300-mesh sieve.

[0049] (2) Add 1kg of carbon fiber powder treated in step (1), 3kg of nylon 66 pellets, and 2kg of polyvinylpyrrolidone into 18L of acetic acid, heat and stir at 100°C for 2 hours to fully dissolve the nylon 66 pellets.

[0050] (3) While vigorously stirring, add 10 L of absolute ethanol to step (2), and precipitate out after standing still. After suction filtration, washing with ethanol, and drying, sieve with a 200-mesh sieve.

[0051] (4) Take step (3) gained carbon fiber-nylon powder 4kg, and flow aid nano silicon dioxide 20g, antioxidant 2,2'-methylene bis-(4-methyl-6-tert-butylphenol ) 10 g, stirred and mixed for 1 h in a vertical mixer to obtain carb...

technical field

[0001] The invention relates to the technical field of selective laser sintering materials. More specifically, it relates to a preparation method of carbon fiber reinforced nylon composite micropowder for selective laser sintering. Background technique

[0002] Selective laser sintering (SLS) is an important technology of 3D printing-additive manufacturing. The computer controls the infrared laser beam, scans and sinters the solid powder layer by layer at a certain speed and energy density, accumulates layers, and finally forms a shaped part. Material performance is a key link in the development of SLS technology, which directly affects the forming speed, precision and physical and chemical properties of sintered samples. Polymer powders represented by nylon 12 and their modified materials have the advantages of low water absorption, low melting point, low density, low shrinkage, heat resistance, and easy molding. source material. However, the strength an...

Examples

Embodiment 1

[0038] (1) Extract 1.5 kg of commercially available carbon fiber powder with acetone in a Soxhlet extractor for 48 h, add 1.0 L of nitric acid with a concentration of 14 mol / L after vacuum drying, and oxidize under reflux for 5 h. Dilute with distilled water, vacuum filter, wash until neutral, dry, and pass through a 300-mesh sieve.

[0039] (2) Add 1kg of carbon fiber powder treated in step (1), 3kg of nylon 12 pellets, and 2kg of polyvinylpyrrolidone into 15L of formic acid, heat and stir at 80°C for 2 hours to fully dissolve the nylon 12 pellets.

[0040] (3) While vigorously stirring, add 10 L of absolute ethanol to step (2), and precipitate out after standing still. After suction filtration, washing with ethanol, and drying, sieve with a 200-mesh sieve.

[0041](4) Take step (3) gained carbon fiber-nylon powder 4kg, and flow aid nano silicon dioxide 20g, antioxidant 2,2'-methylene bis-(4-methyl-6-tert-butylphenol ) 10 g, stirred and mixed for 1 h in a vertical mixer to ...

Embodiment 2

[0043] (1) Commercially available 1.5kg carbon fiber powder was extracted with acetone in a Soxhlet extractor for 48 hours, vacuum-dried, added to a toluene solution to stir and disperse, added an ethanol solution of silane coupling agent KH550, ventilated with nitrogen, heated to reflux for 1 hour, and vacuumed Filter, wash, dry, and pass through a 300-mesh sieve.

[0044] (2) Add 1kg of carbon fiber powder treated in step (1), 3kg of nylon 12 pellets, and 2kg of polyvinylpyrrolidone into 15L of formic acid, heat and stir at 80°C for 2 hours to fully dissolve the nylon 12 pellets.

[0045] (3) While vigorously stirring, add 10 L of absolute ethanol to step (2), and precipitate out after standing still. After suction filtration, washing with ethanol, and drying, sieve with a 200-mesh sieve.

[0046] (4) Take step (3) gained carbon fiber-nylon powder 4kg, and flow aid nano silicon dioxide 20g, antioxidant 2,2'-methylene bis-(4-methyl-6-tert-butylphenol ) 10 g, stirred and mix...

Embodiment 3

[0048] (1) Commercially available 1.5kg carbon fiber powder was extracted with acetone for 48 hours in a Soxhlet extractor, dried in a vacuum, added to 14 mol / L nitric acid, heated to reflux for 5 hours for oxidation. Dilute with distilled water, vacuum filter, wash until neutral, dry, and pass through a 300-mesh sieve.

[0049] (2) Add 1kg of carbon fiber powder treated in step (1), 3kg of nylon 66 pellets, and 2kg of polyvinylpyrrolidone into 18L of acetic acid, heat and stir at 100°C for 2 hours to fully dissolve the nylon 66 pellets.

[0050] (3) While vigorously stirring, add 10 L of absolute ethanol to step (2), and precipitate out after standing still. After suction filtration, washing with ethanol, and drying, sieve with a 200-mesh sieve.

[0051] (4) Take step (3) gained carbon fiber-nylon powder 4kg, and flow aid nano silicon dioxide 20g, antioxidant 2,2'-methylene bis-(4-methyl-6-tert-butylphenol ) 10 g, stirred and mixed for 1 h in a vertical mixer to obtain carb...

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