Forging grain aramid sheet molding compound and preparation method thereof

Abstract

The invention relates to the technical field of aramid fiber composite materials, in particular to a forging grain aramid sheet molding compound and a preparation method thereof.The forging grain aramid sheet molding compound comprises an aramid color silk one-way prepreg, an aramid fiber one-way prepreg, an aramid woven cloth prepreg and flame-retardant epoxy resin; the preparation method comprises the following steps: respectively sizing aramid color yarns, aramid fibers and aramid woven cloth, and then impregnating flame-retardant epoxy resin to obtain an aramid color yarn unidirectional prepreg, an aramid fiber unidirectional prepreg and an aramid woven cloth prepreg; a sizing agent used in the sizing treatment comprises water-soluble polyamide resin prepared by polymerizing alpha, omega-dicarboxyl polyethylene glycol and polyether amine. Aiming at the problems of insufficient aesthetic property, poor impact resistance and the like of the forging grain carbon fiber sheet molding compound in the prior art, the invention provides the forging grain aramid fiber sheet molding compound and the preparation method thereof, and the forging grain aramid fiber sheet molding compound has the advantages of aesthetic property, strong designability, impact resistance and flame retardant property.

Description

Technical Field

[0001] The invention relates to a forged texture aramid sheet molding compound and a preparation method thereof, belonging to the technical field of aramid fiber composite materials. Background Art

[0002] Aramid fiber has high specific strength, high specific modulus, high temperature resistance, acid and alkali resistance, light weight and excellent wear and impact resistance, so it is widely used in aerospace, rail transportation and new energy vehicles. However, with the development of new energy vehicles and low-altitude flight, the demand for lightweight composite materials continues to increase, and more requirements are placed on their appearance texture and decoration.

[0003] Sheet molding compounds appeared in the late 1950s and have attracted widespread attention since their introduction. So far, the main automotive parts that can be replaced by sheet molding compounds (SMC) are: roofs, bumpers, side panels-lining assemblies, radiator grilles, hoods, side panels, trunk lids, battery trays, interior panels, etc. As an advanced new composite material, forged sheet molding compounds have the advantages of light weight, high specific strength, strong design flexibility, high production efficiency, and easy preparation of complex configuration parts. Due to its unique marble texture and light weight and high strength, it has gradually replaced continuous fiber reinforced composites and become a common material for new energy vehicles and low-altitude aircraft.

[0004] In recent years, with the development of the economy, people have put forward more and more demands for forged pattern sheet molding compounds, which not only require forged pattern sheet molding compounds to have light weight and high strength, but also hope that they are more beautiful and decorative. At present, carbon fiber sheet molding compounds are commonly used materials with marble texture, high performance and lightweight. Chinese patent CN118144372A proposes a forged pattern carbon fiber sheet molding compound and a preparation method thereof, by which the complex shape of forged texture carbon fiber composite materials can be manufactured, and the product surface is free of defects such as pinholes, bubbles, and lack of glue. Chinese patent application CN118752802A proposes a gold foil-modified carbon fiber sheet molding compound, which sprinkles gold foil on the outer surface of the carbon fiber base sheet to enhance its aesthetics. However, due to its inherent black color and the inability to change the color, the design aesthetics is poor; in addition, due to the higher modulus of carbon fiber, its toughness and impact resistance are poor.

[0005] In addition, due to its own inertness and smoothness, aramid fiber is difficult to form a relatively good interface with the resin, and is prone to debonding and stratification with the resin during preparation and use, resulting in a decrease in the mechanical properties of the prepared sheet molding compound. Therefore, it is of great significance to develop a flame-retardant, impact-resistant, multi-color forged aramid sheet molding compound. Summary of the invention

[0006] Aiming at the problems of insufficient aesthetics and poor impact resistance of forged carbon fiber sheet molding materials in the prior art, the present invention proposes a forged aramid sheet molding material and a preparation method thereof. The forged aramid sheet molding material has the advantages of aesthetics, strong designability, impact resistance and flame retardancy.

[0007] The technical solution of the present invention to solve the above technical problems is as follows: a forged texture aramid sheet molding compound, the forged texture aramid sheet molding compound comprising aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg, aramid woven cloth prepreg and flame retardant epoxy resin; Aramid colored yarn, aramid fiber and aramid woven fabric are sizing treated respectively, and then impregnated with flame retardant epoxy resin to obtain the aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; The sizing agent used in the sizing treatment includes a water-soluble polyamide resin prepared by polymerizing α,ω-dicarboxyl polyethylene glycol and polyether amine.

[0008] Furthermore, the width of the aramid colored yarn unidirectional prepreg is 15-20 mm; The aramid colored yarn unidirectional prepreg is composed of one or more colors of three primary colors, namely red, yellow and blue, and colors mixed by the three primary colors.

[0009] Furthermore, the aramid fiber unidirectional prepreg is made by impregnating a primary color aramid fiber unidirectional tape with a flame retardant epoxy resin; The aramid woven fabric prepreg is prepared by sizing and impregnating one or more of aramid plain fabric and aramid twill fabric with flame retardant epoxy resin.

[0010] Furthermore, the preparation method of the water-soluble polyamide resin is: pyridine, triphenyl phosphite, calcium chloride and lithium chloride are added to N-methylpyrrolidone, and the calcium chloride and lithium chloride are completely dissolved by stirring, and then polyetheramine and α, ω-dicarboxyl polyethylene glycol are added to the system, and the system is heated and stirred until the system becomes completely clear, and then the system is heated under the protection of an inert gas to carry out a polymerization reaction, and after the reaction is completed, the water-soluble polyamide resin is obtained by post-treatment.

[0011] Furthermore, the water-soluble polyamide resin is dissolved in water to prepare an aqueous solution with a concentration of 5-10 wt%, and then a wetting agent is added to the aqueous solution in an amount of 0.1-0.2% by weight of the aqueous solution to obtain the sizing agent.

[0012] The present invention also discloses a method for preparing a forged texture aramid sheet molding compound, the preparation method comprising: S1, sizing aramid colored yarn, aramid fiber and aramid woven fabric, and then respectively impregnating them with flame retardant epoxy resin to obtain aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; S2, cutting the aramid colored yarn unidirectional prepreg into chopped fiber bundles, evenly spreading the chopped fiber bundles on the aramid fiber unidirectional prepreg, and then pressing to obtain a forged textured aramid fiber prepreg; S3, laying a forged texture aramid fiber prepreg and an aramid woven fabric prepreg on the mold cavity surface in sequence, and then laying an isolation film, a breathable felt, and a vacuum bag in sequence, and pressing a flame-retardant epoxy resin into the composite material by vacuuming; the forged texture aramid fiber prepreg having a side with a chopped fiber bundle is in contact with the mold cavity surface; S4, heating and pressurizing the entire mold after the composite material is laid in step S3 to achieve curing and molding to obtain the forged aramid sheet molding compound.

[0013] Furthermore, in step S2, the length of the chopped fiber bundle is 20 mm-40 mm; and the thickness of the chopped fiber bundle spread on the aramid fiber unidirectional prepreg is 0.5 mm-1.5 mm.

[0014] Furthermore, in step S2, the pressing conditions are: temperature 145-155° C., pressure 1.0-2.0 MPa, and time 60-120 min.

[0015] Furthermore, the amount of the flame retardant epoxy resin is 30%-40% of the total mass of the forged aramid sheet molding compound.

[0016] Furthermore, in step S4, during the curing process, the injection pressure is 0.1-1.0 MPa; the heating is gradient heating, and the gradient heating process is: from room temperature, at a heating rate of 4-5°C / min, the temperature is increased to 100±2°C, and then kept warm for 20-30min; then at a heating rate of 4-5°C / min, the temperature is continued to be increased to 145±5°C, and kept warm for 100-120min.

[0017] The beneficial effects of the present invention are: (1) The present invention uses aramid colored yarn unidirectional prepreg as the forging texture, which can overcome the shortcomings of the original carbon fiber forging texture of single color and poor designability, and can provide a more beautiful texture design. In addition, the inherent flexibility of aramid fiber can also improve the impact resistance of the product.

[0018] (2) The present invention uses aramid woven fabric prepreg as raw material. Compared with the high modulus of carbon fiber woven fabric, it can improve the damage tolerance and impact resistance of the product. The inherent flame retardancy of aramid fiber can also improve the flame retardant performance of the product.

[0019] (3) The present invention uses a self-made water-soluble polyamide resin as a sizing agent. Compared with the traditional sizing agent, the water-soluble polyamide resin sizing agent is more environmentally friendly, and the sizing agent has a similar structure to the aramid fiber, which can improve the adhesion of the resin to the aramid fiber.

[0020] (4) The present invention uses transparent, flame-retardant epoxy resin as the base resin, which can improve the flame retardant properties of the product and can more fully demonstrate the design and multi-color display of the product. DETAILED DESCRIPTION

[0021] The specific implementation of the present invention is described in detail below. The present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0023] A forged aramid sheet molding compound, comprising aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg, aramid woven cloth prepreg and flame retardant epoxy resin; Aramid colored yarn, aramid fiber and aramid woven fabric are sizing treated respectively, and then impregnated with flame retardant epoxy resin to obtain the aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; The sizing agent used in the sizing treatment includes a water-soluble polyamide resin prepared by polymerizing α,ω-dicarboxyl polyethylene glycol and polyether amine.

[0024] Specifically, the width of the aramid colored yarn unidirectional prepreg is 15-20 mm; The aramid colored yarn unidirectional prepreg is composed of one or more colors of three primary colors, namely red, yellow and blue, and colors mixed by the three primary colors.

[0025] Specifically, the aramid fiber unidirectional prepreg is made by impregnating a primary color aramid fiber unidirectional tape with a flame retardant epoxy resin; The aramid woven fabric prepreg is prepared by sizing and impregnating one or more of aramid plain fabric and aramid twill fabric with flame retardant epoxy resin.

[0026] More specifically, the flame retardant epoxy resin is a transparent, flame retardant epoxy resin, which can be obtained by self-production or commercial purchase, such as Huibo New Materials GT-910A / B or GT-920A / B.

[0027] More specifically, the aramid fiber used in the embodiment of the present invention is TH529S; the aramid colored yarn is of the same model as the aramid fiber, but is colored; among the aramid woven fabrics, the aramid plain fabric is TH51081, and the aramid twill fabric is TH5209.

[0028] Specifically, the preparation method of the water-soluble polyamide resin is as follows: pyridine, triphenyl phosphite, calcium chloride and lithium chloride are added to N-methylpyrrolidone, and the calcium chloride and lithium chloride are completely dissolved by stirring, and then polyetheramine and α, ω-dicarboxyl polyethylene glycol are added to the system, and the system is heated and stirred until the system becomes completely clear, and then the system is heated under the protection of an inert gas to carry out a polymerization reaction, and after the reaction is completed, the water-soluble polyamide resin is obtained by post-processing.

[0029] More specifically, the polyetheramine is polyetheramine D400 (Mw=400); the Mn of α,ω-dicarboxyl polyethylene glycol is 600.

[0030] Specifically, the water-soluble polyamide resin is dissolved in water to prepare an aqueous solution with a concentration of 5-10 wt %, and then a wetting agent in an amount of 0.1-0.2 wt % of the aqueous solution is added to the aqueous solution to obtain the sizing agent.

[0031] More specifically, the wetting agent is ECORO FCRCORE® 3747 or HS-465.

[0032] More specifically, the sizing operation is: aramid fiber, aramid colored yarn and aramid woven fabric are placed in a sizing agent for dipping and coating, and after a residence time of 25-35 seconds, hot air drying is performed at 95-100° C. for 4-5 minutes to form a uniform sizing layer to obtain aramid fiber, aramid colored yarn and aramid woven fabric after sizing.

[0033] A method for preparing a forged texture aramid sheet molding compound, the preparation method comprising: S1, sizing aramid fiber, aramid colored yarn and aramid woven fabric, and then respectively impregnating them with flame retardant epoxy resin to obtain aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; S2, cutting the aramid colored yarn unidirectional prepreg into chopped fiber bundles, evenly spreading the chopped fiber bundles on the aramid fiber unidirectional prepreg, and then pressing to obtain a forged textured aramid fiber prepreg; S3, laying a forged texture aramid fiber prepreg and an aramid woven fabric prepreg on the mold cavity surface in sequence, and then laying an isolation film, a breathable felt, and a vacuum bag in sequence, and pressing a flame-retardant epoxy resin into the composite material by vacuuming; the forged texture aramid fiber prepreg having a side with a chopped fiber bundle is in contact with the mold cavity surface; S4, heating and pressurizing the entire mold after the composite material is laid in step S3 to achieve curing and molding to obtain the forged aramid sheet molding compound.

[0034] Specifically, in step S2, the length of the chopped fiber bundle is 20 mm to 40 mm; the thickness of the chopped fiber bundle spread on the aramid fiber unidirectional prepreg is 0.5 mm to 1.5 mm; In step S2, the pressing conditions are: temperature 145-155°C, pressure 1.0-2.0 MPa, and time 60-120 min.

[0035] Specifically, the amount of the flame retardant epoxy resin is 30%-40% of the total mass of the forged aramid sheet molding compound.

[0036] Specifically, in step S4, during the curing process, the injection pressure is 0.1-1 MPa; the heating is gradient heating, and the gradient heating process is: from room temperature, at a heating rate of 4-5°C / min, the temperature is increased to 100±2°C, and then kept warm for 20-30min; then at a heating rate of 4-5°C / min, the temperature is continued to be increased to 145±5°C, and kept warm for 100-120min.

[0037] More specifically, the thickness of the forged texture aramid sheet molding compound finally obtained is 2-5 mm.

[0038] More specifically, the isolation membrane (SAFECLEAR®), breathable felt (AIRMAT), and vacuum bag (AIRSAFETY®) used in the embodiments of the present invention are all purchased from Hebei Feiom Composite Materials Co., Ltd.

[0039] Example 1

[0040] A forged aramid sheet molding compound, comprising aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg, aramid woven cloth prepreg and flame retardant epoxy resin; the aramid colored yarn unidirectional prepreg has a width of 20 mm and is red; the aramid woven cloth used in the aramid woven cloth prepreg is aramid plain fabric, and the flame retardant epoxy resin is Huibo New Material GT-910A / B.

[0041] A method for preparing a forged aramid sheet molding compound is as follows: S1, sizing aramid colored yarn, aramid fiber and aramid woven fabric, and then respectively impregnating them with flame retardant epoxy resin to obtain aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; The preparation method of the sizing agent is as follows: a water-soluble polyamide resin is dissolved in water to prepare an aqueous solution with a concentration of 8wt%, and then a wetting agent with a mass percentage of 0.1% of the aqueous solution is added to the aqueous solution to obtain the sizing agent.

[0042] The preparation method of the water-soluble polyamide resin is as follows: 12 mL of N-methylpyrrolidone, 2 mL of pyridine, 6.2 g of triphenyl phosphite, 0.6 g of calcium chloride and 0.2 g of lithium chloride are added into a reaction bottle, and the calcium chloride and lithium chloride are completely dissolved by stirring; 4 g of polyetheramine D400 and 6 g of α,ω-dicarboxyl polyethylene glycol are continuously added into the system, and the system is heated and stirred until the system becomes completely clear, and then the system is evacuated 3 times, the air in the system is replaced with nitrogen, the system is sealed, and the reaction is stirred in an oil bath at 110° C. for 36 hours, and the water-soluble polyamide resin can be obtained by precipitation, filtration, washing and drying.

[0043] The specific operation of sizing treatment is: put aramid fiber, aramid colored yarn and aramid woven fabric into sizing agent for dipping and coating, stay for 30 seconds, and then dry with hot air at 100°C for 5 minutes to form a uniform sizing layer to obtain aramid fiber, aramid colored yarn and aramid woven fabric after sizing.

[0044] S2, cutting the aramid colored yarn unidirectional prepreg into chopped fiber bundles, evenly spreading the chopped fiber bundles on the aramid fiber unidirectional prepreg, and then pressing to obtain a forged textured aramid fiber prepreg; The length of the chopped fiber bundle is 20 mm; the thickness of the chopped fiber bundle spread on the aramid fiber unidirectional prepreg is 0.5 mm-1.0 mm; The pressing conditions are: temperature 150° C., pressure 1 MPa, and time 120 min.

[0045] S3, laying a forged texture aramid fiber prepreg and an aramid woven fabric prepreg on the mold cavity surface in sequence, and then laying an isolation film, a breathable felt, and a vacuum bag in sequence, and pressing a flame-retardant epoxy resin into the composite material by vacuuming; the forged texture aramid fiber prepreg having a side with a chopped fiber bundle is in contact with the mold cavity surface; S4, heating and pressurizing the entire mold after the composite material is laid in step S3 to achieve curing and molding to obtain the forged aramid sheet molding compound; The amount of the flame retardant epoxy resin accounts for 36% of the total mass of the forged aramid sheet molding compound; During the curing process, the injection pressure is 0.3 MPa; the heating is gradient heating, and the gradient heating process is: from room temperature, the temperature is increased to 100°C at a heating rate of 5°C / min, and then kept warm for 30 minutes; then the temperature is continued to be increased to 145°C at a heating rate of 5°C / min, and kept warm for 120 minutes.

[0046] Example 2

[0047] A forged aramid sheet molding compound, comprising aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg, aramid woven cloth prepreg and flame retardant epoxy resin; the aramid colored yarn unidirectional prepreg has a width of 15 mm and is yellow; the aramid woven cloth used in the aramid woven cloth prepreg is aramid twill cloth, and the flame retardant epoxy resin is Huibo New Material GT-920A / B.

[0048] A method for preparing a forged aramid sheet molding compound is as follows: S1, sizing aramid colored yarn, aramid fiber and aramid woven fabric, and then respectively impregnating them with flame retardant epoxy resin to obtain aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; The preparation method of the sizing agent is as follows: a water-soluble polyamide resin is dissolved in water to prepare an aqueous solution with a concentration of 10wt%, and then a wetting agent with a mass percentage of 0.2% of the aqueous solution is added to the aqueous solution to obtain the sizing agent.

[0049] The preparation method of the water-soluble polyamide resin is as follows: 12 mL of N-methylpyrrolidone, 2 mL of pyridine, 6.2 g of triphenyl phosphite, 0.6 g of calcium chloride and 0.2 g of lithium chloride are added into a reaction bottle, and the calcium chloride and lithium chloride are completely dissolved by stirring; 4 g of polyetheramine D400 and 6 g of α,ω-dicarboxyl polyethylene glycol are continuously added into the system, and the system is heated and stirred until the system becomes completely clear, and then the system is evacuated 3 times, the air in the system is replaced by nitrogen, the system is sealed, and the reaction is stirred in an oil bath at 105° C. for 36 hours, and the water-soluble polyamide resin can be obtained by precipitation, filtration, washing and drying.

[0050] The specific operation of sizing treatment is: put the aramid fiber, aramid colored silk and aramid woven fabric into the sizing agent for dipping and coating, after a residence time of 20 seconds, and then dry with hot air at 95°C for 5 minutes to form a uniform sizing layer to obtain the sizing-treated aramid fiber, aramid colored silk and aramid woven fabric.

[0051] S2, cutting the aramid colored yarn unidirectional prepreg into chopped fiber bundles, evenly spreading the chopped fiber bundles on the aramid fiber unidirectional prepreg, and then pressing to obtain a forged textured aramid fiber prepreg; The length of the chopped fiber bundle is 30 mm; the thickness of the chopped fiber bundle spread on the aramid fiber unidirectional prepreg is 1.0 mm-1.5 mm; The pressing conditions are: temperature 155° C., pressure 2.0 MPa, and time 60 min.

[0052] S3, laying a forged texture aramid fiber prepreg and an aramid woven fabric prepreg on the mold cavity surface in sequence, and then laying an isolation film, a breathable felt, and a vacuum bag in sequence, and pressing a flame-retardant epoxy resin into the composite material by vacuuming; the forged texture aramid fiber prepreg having a side with a chopped fiber bundle is in contact with the mold cavity surface; S4, heating and pressurizing the entire mold after the composite material is laid in step S3 to achieve curing and molding to obtain the forged aramid sheet molding compound; The amount of the flame retardant epoxy resin accounts for 30% of the total mass of the forged aramid sheet molding compound; During the curing process, the injection pressure is 0.5 MPa; the heating is gradient heating, and the gradient heating process is: from room temperature, the temperature is increased to 102°C at a heating rate of 4°C / min, and then kept warm for 20 minutes; then the temperature is continued to be increased to 150°C at a heating rate of 4°C / min, and kept warm for 100 minutes.

[0053] Example 3

[0054] A forged aramid sheet molding compound, comprising aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg, aramid woven cloth prepreg and flame retardant epoxy resin; the aramid colored yarn unidirectional prepreg has a width of 15 mm and is yellow; the aramid woven cloth used in the aramid woven cloth prepreg is aramid plain fabric, and the flame retardant epoxy resin is Huibo New Material GT-920A / B.

[0055] A method for preparing a forged aramid sheet molding compound is as follows: S1, sizing aramid colored yarn, aramid fiber and aramid woven fabric, and then respectively impregnating them with flame retardant epoxy resin to obtain aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; The preparation method of the sizing agent is as follows: a water-soluble polyamide resin is dissolved in water to prepare an aqueous solution with a concentration of 5wt%, and then a wetting agent with a mass percentage of 0.1% of the aqueous solution is added to the aqueous solution to obtain the sizing agent.

[0056] The preparation method of the water-soluble polyamide resin is as follows: 12 mL of N-methylpyrrolidone, 2 mL of pyridine, 6.2 g of triphenyl phosphite, 0.6 g of calcium chloride and 0.2 g of lithium chloride are added into a reaction bottle, and the calcium chloride and lithium chloride are completely dissolved by stirring; 4 g of polyetheramine D400 and 6 g of α,ω-dicarboxyl polyethylene glycol are continuously added into the system, and the system is heated and stirred until the system becomes completely clear, and then the system is evacuated 3 times, the air in the system is replaced with nitrogen, the system is sealed, and the reaction is stirred in an oil bath at 110° C. for 36 hours, and the water-soluble polyamide resin can be obtained by precipitation, filtration, washing and drying.

[0057] The specific operation of sizing treatment is: put aramid fiber, aramid colored yarn and aramid woven fabric into sizing agent for dipping and coating, stay for 30 seconds, and then dry with 100°C hot air for 4 minutes to form a uniform sizing layer to obtain aramid fiber, aramid colored yarn and aramid woven fabric after sizing.

[0058] S2, cutting the aramid colored yarn unidirectional prepreg into chopped fiber bundles, evenly spreading the chopped fiber bundles on the aramid fiber unidirectional prepreg, and then pressing to obtain a forged textured aramid fiber prepreg; The length of the chopped fiber bundle is 40 mm; the thickness of the chopped fiber bundle spread on the aramid fiber unidirectional prepreg is 1.0 mm-1.5 mm; The pressing conditions are: temperature 145° C., pressure 1.5 MPa, and time 100 min.

[0059] S3, laying a forged texture aramid fiber prepreg and an aramid woven fabric prepreg on the mold cavity surface in sequence, and then laying an isolation film, a breathable felt, and a vacuum bag in sequence, and pressing a flame-retardant epoxy resin into the composite material by vacuuming; the forged texture aramid fiber prepreg having a side with a chopped fiber bundle is in contact with the mold cavity surface; S4, heating and pressurizing the entire mold after the composite material is laid in step S3 to achieve curing and molding to obtain the forged aramid sheet molding compound; The amount of the flame retardant epoxy resin accounts for 40% of the total mass of the forged aramid sheet molding compound; During the curing process, the injection pressure is 1.0 MPa; the heating is gradient heating, and the gradient heating process is: from room temperature, the temperature is increased to 98°C at a heating rate of 5°C / min, and then kept warm for 30 minutes; then the temperature is continued to be increased to 140°C at a heating rate of 5°C / min, and kept warm for 120 minutes.

[0060] Comparative Example 1 The forged aramid sheet molding compound was prepared by the same method as in Example 1, except that no aramid woven fabric prepreg was added in this comparative example 1. The details are as follows: A forged texture aramid sheet molding compound, comprising aramid color yarn unidirectional prepreg, aramid fiber unidirectional prepreg and flame retardant epoxy resin; the aramid color yarn unidirectional prepreg has a width of 8-10 mm and is red; the flame retardant epoxy resin is Huibo New Material GT-910A / B.

[0061] A method for preparing a forged aramid sheet molding compound is as follows: S1, sizing the aramid colored yarn and the aramid fiber, and then respectively impregnating them with a flame retardant epoxy resin to obtain an aramid colored yarn unidirectional prepreg and an aramid fiber unidirectional prepreg; The preparation method of the sizing agent is as follows: a water-soluble polyamide resin is dissolved in water to prepare an aqueous solution with a concentration of 8wt%, and then a wetting agent with a mass percentage of 0.1% of the aqueous solution is added to the aqueous solution to obtain the sizing agent.

[0062] The preparation method of the water-soluble polyamide resin is as follows: 12 mL of N-methylpyrrolidone, 2 mL of pyridine, 6.2 g of triphenyl phosphite, 0.6 g of calcium chloride and 0.2 g of lithium chloride are added into a reaction bottle, and the calcium chloride and lithium chloride are completely dissolved by stirring; 4 g of polyetheramine D400 and 6 g of α,ω-dicarboxyl polyethylene glycol are continuously added into the system, and the system is heated and stirred until the system becomes completely clear, and then the system is evacuated 3 times, the air in the system is replaced with nitrogen, the system is sealed, and the reaction is stirred in an oil bath at 110° C. for 36 hours, and the water-soluble polyamide resin can be obtained by precipitation, filtration, washing and drying.

[0063] The specific operation of sizing treatment is: put the aramid fiber and aramid colored silk into the sizing agent for dipping and coating, and after a residence time of 30 seconds, dry it with hot air at 100°C for 5 minutes to form a uniform sizing layer to obtain the sizing aramid fiber and aramid colored silk.

[0064] S2, cutting the aramid colored yarn unidirectional prepreg into chopped fiber bundles, evenly spreading the chopped fiber bundles on the aramid fiber unidirectional prepreg, and then pressing to obtain a forged textured aramid fiber prepreg; The length of the chopped fiber bundle is 20 mm; the thickness of the chopped fiber bundle spread on the aramid fiber unidirectional prepreg is 0.5 mm-1.0 mm; The pressing conditions are: temperature 150° C., pressure 1.0 MPa, and time 120 min.

[0065] S3, laying the forged texture aramid fiber prepreg on the mold cavity surface, and then laying the isolation film, breathable felt, and vacuum bag in sequence, and pressing the flame-retardant epoxy resin into the composite material by vacuuming; the forged texture aramid fiber prepreg having a side of the chopped fiber bundle is in contact with the mold cavity surface; S4, heating and pressurizing the entire mold after the composite material is laid in step S3 to achieve curing and molding to obtain the forged aramid sheet molding compound; The amount of the flame retardant epoxy resin accounts for 36% of the total mass of the forged aramid sheet molding compound; During the curing process, the injection pressure is 0.3 MPa; the heating is gradient heating, and the gradient heating process is: from room temperature, the temperature is increased to 100°C at a heating rate of 5°C / min, and then kept warm for 30 minutes; then the temperature is continued to be increased to 145°C at a heating rate of 5°C / min, and kept warm for 120 minutes.

[0066] Comparative Example 2 The forged texture aramid sheet molding compound was prepared by the same method as in Example 1, except that: in this comparative example 2, the aramid colored yarn unidirectional prepreg and the aramid fiber unidirectional prepreg were replaced with forged texture carbon fiber prepreg. The details are as follows: A forged aramid sheet molding compound, comprising a forged carbon fiber prepreg, an aramid woven cloth prepreg and a flame retardant epoxy resin; the forged carbon fiber prepreg is prepared from a Zhongfu Shenying T700 / 12k carbon fiber bundle; the aramid woven cloth used in the aramid woven cloth prepreg is an aramid plain fabric (TH51081), and the flame retardant epoxy resin is Huibo New Materials GT-910A / B.

[0067] A method for preparing a forged aramid sheet molding compound is as follows: S1, sizing the carbon fiber bundle and the aramid woven fabric, and then respectively impregnating them with flame-retardant epoxy resin to obtain a carbon fiber unidirectional prepreg and an aramid woven fabric prepreg; The preparation method of the sizing agent is as follows: a water-soluble polyamide resin is dissolved in water to prepare an aqueous solution with a concentration of 8wt%, and then a wetting agent with a mass percentage of 0.1% of the aqueous solution is added to the aqueous solution to obtain the sizing agent.

[0068] The preparation method of the water-soluble polyamide resin is as follows: 12 mL of N-methylpyrrolidone, 2 mL of pyridine, 6.2 g of triphenyl phosphite, 0.6 g of calcium chloride and 0.2 g of lithium chloride are added into a reaction bottle, and the calcium chloride and lithium chloride are completely dissolved by stirring; 4 g of polyetheramine D400 and 6 g of α,ω-dicarboxyl polyethylene glycol are continuously added into the system, and the system is heated and stirred until the system becomes completely clear, and then the system is evacuated 3 times, the air in the system is replaced with nitrogen, the system is sealed, and the reaction is stirred in an oil bath at 110° C. for 36 hours, and the water-soluble polyamide resin can be obtained by precipitation, filtration, washing and drying.

[0069] The specific operation of the sizing treatment is: put the forged texture carbon fiber and aramid woven cloth into the sizing agent for dipping and coating, and after a residence time of 30 seconds, dry it with hot air at 100°C for 5 minutes to form a uniform sizing layer to obtain the sizing aramid fiber, forged texture carbon fiber and aramid woven cloth.

[0070] S2, cutting the carbon fiber unidirectional prepreg into the same size as the aramid colored silk unidirectional prepreg, and then evenly spreading it on the carbon fiber unidirectional prepreg, and then pressing it to obtain the forged texture carbon fiber prepreg; The spreading thickness of the forged texture carbon fiber prepreg is 0.5mm-1.0mm; The pressing conditions are: temperature 150° C., pressure 1.0 MPa, and time 120 min.

[0071] S3, laying the forged texture carbon fiber prepreg and the aramid woven fabric prepreg on the mold cavity surface in sequence, and then laying the isolation film, breathable felt, and vacuum bag in sequence, and pressing the flame-retardant epoxy resin into the composite material by vacuuming; the forged texture aramid fiber prepreg has one side of the forged texture carbon fiber prepreg in contact with the mold cavity surface; S4, heating and pressurizing the entire mold after the composite material is laid in step S3 to achieve curing and molding to obtain the forged aramid sheet molding compound; The amount of the flame retardant epoxy resin accounts for 36% of the total mass of the forged aramid sheet molding compound; During the curing process, the injection pressure is 0.3 MPa; the heating is gradient heating, and the gradient heating process is: from room temperature, the temperature is increased to 100°C at a heating rate of 5°C / min, and then kept warm for 30 minutes; then the temperature is continued to be increased to 145°C at a heating rate of 5°C / min, and kept warm for 120 minutes.

[0072] Comparative Example 3 The forged aramid sheet molding compound was prepared by the same method as in Example 1, except that the flame retardant epoxy resin was replaced with a conventional resin in Comparative Example 3. The details are as follows: A forged aramid sheet molding compound, comprising aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg, aramid woven cloth prepreg and resin; the aramid colored yarn unidirectional prepreg has a width of 8-10 mm and is red; the aramid woven cloth prepreg uses aramid plain weave fabric, and the resin is Huibo New Material AM-8931A / B.

[0073] A method for preparing a forged aramid sheet molding compound is as follows: S1, sizing the aramid colored yarn, aramid fiber and aramid woven fabric, and then respectively impregnating them with resin to obtain aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; The preparation method of the sizing agent is as follows: a water-soluble polyamide resin is dissolved in water to prepare an aqueous solution with a concentration of 8wt%, and then a wetting agent with a mass percentage of 0.1% of the aqueous solution is added to the aqueous solution to obtain the sizing agent.

[0074] The preparation method of the water-soluble polyamide resin is as follows: 12 mL of N-methylpyrrolidone, 2 mL of pyridine, 6.2 g of triphenyl phosphite, 0.6 g of calcium chloride and 0.2 g of lithium chloride are added into a reaction bottle, and the calcium chloride and lithium chloride are completely dissolved by stirring; 4 g of polyetheramine D400 and 6 g of α,ω-dicarboxyl polyethylene glycol are continuously added into the system, and the system is heated and stirred until the system becomes completely clear, and then the system is evacuated 3 times, the air in the system is replaced with nitrogen, the system is sealed, and the reaction is stirred in an oil bath at 110° C. for 36 hours, and the water-soluble polyamide resin can be obtained by precipitation, filtration, washing and drying.

[0075] The specific operation of sizing treatment is: put aramid fiber, aramid colored silk and aramid woven cloth fiber into sizing agent for dipping and coating, after residence time of 30 seconds, and then dry with hot air at 100°C for 5 minutes to form a uniform sizing layer to obtain aramid fiber, aramid colored silk and aramid woven cloth after sizing.

[0076] S2, cutting the aramid colored yarn unidirectional prepreg into chopped fiber bundles, evenly spreading the chopped fiber bundles on the aramid fiber unidirectional prepreg, and then pressing to obtain a forged textured aramid fiber prepreg; The length of the chopped fiber bundle is 20 mm; the thickness of the chopped fiber bundle spread on the aramid fiber unidirectional prepreg is 0.5 mm-1.0 mm; The pressing conditions are: temperature 120° C., pressure 1 MPa, and time 30 min.

[0077] S3, laying the forged texture aramid fiber prepreg and the aramid woven fabric prepreg on the mold cavity surface in sequence, and then laying the isolation film, breathable felt, and vacuum bag in sequence, and pressing the resin into the composite material by vacuuming; the forged texture aramid fiber prepreg having a side with chopped fiber bundles is in contact with the mold cavity surface; S4, heating and pressurizing the entire mold after the composite material is laid in step S3 to achieve curing and molding to obtain the forged aramid sheet molding compound; The amount of the resin accounts for 36% of the total mass of the forged aramid sheet molding compound; During the curing process, the injection pressure is 0.3 MPa; the heating is gradient heating, and the gradient heating process is: from room temperature, the temperature is increased to 100°C at a heating rate of 5°C / min, and then kept warm for 30 minutes; then the temperature is continued to be increased to 145°C at a heating rate of 5°C / min, and kept warm for 120 minutes.

[0078] Comparative Example 4 The forged texture aramid sheet molding compound was prepared by the same method as in Example 1, except that: in this comparative example 4, the aramid fiber, aramid colored yarn and aramid woven fabric were not subjected to sizing treatment. The details are as follows: A forged aramid sheet molding compound, comprising aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg, aramid woven cloth prepreg and flame retardant epoxy resin; the aramid colored yarn unidirectional prepreg has a width of 8-10 mm, and the aramid colored yarn unidirectional prepreg is red; the aramid woven cloth used in the aramid woven cloth prepreg is aramid plain fabric, and the flame retardant epoxy resin is Huibo New Material GT-910A / B.

[0079] A method for preparing a forged aramid sheet molding compound is as follows: S1, respectively impregnating aramid colored yarn, aramid fiber and aramid woven fabric with flame-retardant epoxy resin to obtain aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; S2, cutting the aramid colored yarn unidirectional prepreg into chopped fiber bundles, evenly spreading the chopped fiber bundles on the aramid fiber unidirectional prepreg, and then pressing to obtain a forged textured aramid fiber prepreg; The length of the chopped fiber bundle is 20 mm; the thickness of the chopped fiber bundle spread on the aramid fiber unidirectional prepreg is 0.5 mm-1.0 mm; The pressing conditions are: temperature 150° C., pressure 1.0 MPa, and time 120 min.

[0080] S3, laying a forged texture aramid fiber prepreg and an aramid woven fabric prepreg on the mold cavity surface in sequence, and then laying an isolation film, a breathable felt, and a vacuum bag in sequence, and pressing a flame-retardant epoxy resin into the composite material by vacuuming; the forged texture aramid fiber prepreg having a side with a chopped fiber bundle is in contact with the mold cavity surface; S4, heating and pressurizing the entire mold after the composite material is laid in step S3 to achieve curing and molding to obtain the forged aramid sheet molding compound; The amount of the flame retardant epoxy resin accounts for 36% of the total mass of the forged aramid sheet molding compound; During the curing process, the injection pressure is 0.3 MPa; the heating is gradient heating, and the gradient heating process is: from room temperature, the temperature is increased to 100°C at a heating rate of 5°C / min, and then kept warm for 30 minutes; then the temperature is continued to be increased to 145°C at a heating rate of 5°C / min, and kept warm for 120 minutes.

[0081] Comparative Example 5 The forged aramid sheet molding compound was prepared by the same method as in Example 1, except that the sizing agent in this comparative example 5 was replaced with a conventional waterborne polyurethane resin (R025 sizing agent). The details are as follows: A forged aramid sheet molding compound, comprising aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg, aramid woven cloth prepreg and flame retardant epoxy resin; the aramid colored yarn unidirectional prepreg has a width of 8-10 mm, and the aramid colored yarn unidirectional prepreg is red; the aramid woven cloth used in the aramid woven cloth prepreg is aramid plain fabric, and the flame retardant epoxy resin is Huibo New Material GT-910A / B.

[0082] A method for preparing a forged aramid sheet molding compound is as follows: S1, sizing aramid colored yarn, aramid fiber and aramid woven fabric, and then respectively impregnating them with flame retardant epoxy resin to obtain aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; The preparation method of the sizing agent is as follows: waterborne polyurethane resin is dissolved in water to prepare an aqueous solution with a concentration of 8wt%, and then a wetting agent with a mass percentage of 0.1% of the aqueous solution is added to the aqueous solution to obtain the sizing agent.

[0083] The specific operation of sizing treatment is: put aramid fiber, aramid colored silk and aramid woven cloth fiber into sizing agent for dipping and coating, stay for 30 seconds, and then dry with hot air at 120°C for 5 minutes to form a uniform sizing layer to obtain aramid fiber, aramid colored silk and aramid woven cloth after sizing.

[0084] S2, cutting the aramid colored yarn unidirectional prepreg into chopped fiber bundles, evenly spreading the chopped fiber bundles on the aramid fiber unidirectional prepreg, and then pressing to obtain a forged textured aramid fiber prepreg; The length of the chopped fiber bundle is 20 mm; the thickness of the chopped fiber bundle spread on the aramid fiber unidirectional prepreg is 0.5 mm-1.0 mm; The pressing conditions are: temperature 150° C., pressure 1.0 MPa, and time 120 min.

[0085] S3, laying a forged texture aramid fiber prepreg and an aramid woven fabric prepreg on the mold cavity surface in sequence, and then laying an isolation film, a breathable felt, and a vacuum bag in sequence, and pressing a flame-retardant epoxy resin into the composite material by vacuuming; the forged texture aramid fiber prepreg having a side with a chopped fiber bundle is in contact with the mold cavity surface; S4, heating and pressurizing the entire mold after the composite material is laid in step S3 to achieve curing and molding to obtain the forged aramid sheet molding compound; The amount of the flame retardant epoxy resin accounts for 36% of the total mass of the forged aramid sheet molding compound; During the curing process, the injection pressure is 0.3 MPa; the heating is gradient heating, and the gradient heating process is: from room temperature, the temperature is increased to 100°C at a heating rate of 5°C / min, and then kept warm for 30 minutes; then the temperature is continued to be increased to 145°C at a heating rate of 5°C / min, and kept warm for 120 minutes.

[0086] The forged aramid sheet molding compounds prepared in the above examples and comparative examples were subjected to performance tests, and the specific results are shown in Table 1 below.

[0087] Table 1 Performance test results of forged aramid sheet molding compound

[0088] It can be seen from the data in the above table that the forged aramid sheet molding compound prepared by the preparation method of the present invention in Examples 1 to 3 has more excellent impact resistance, and the surface color is diversified, rich in color, and has better aesthetics; at the same time, it has good flame retardant properties, strong interlayer bonding, and excellent mechanical properties.

[0089] From the comparison of the results of Comparative Example 1 and Example 1, it can be seen that if aramid woven cloth prepreg is not added when preparing the forged aramid sheet molding compound, during the impact process, the aramid unidirectional prepreg cannot evenly disperse the impact stress in all directions, and the higher modulus of the aramid unidirectional prepreg makes it more susceptible to impact damage.

[0090] From the comparison of the results of Comparative Example 2 and Example 1, it can be seen that if the aramid colored yarn unidirectional prepreg is replaced with the forged texture carbon fiber prepreg when preparing the forged texture aramid sheet molding compound, the surface color of the forged texture aramid sheet molding compound product is single, with only black forging texture, while the surface color of the forged texture aramid fiber sheet molding compound prepared with aramid colored yarn is diversified, rich in color, and has better aesthetics. In addition, since the sheet molding compound uses a large amount of carbon fiber, the impact resistance of the molding compound is reduced, but due to the addition of carbon fiber, the mechanical properties of the aramid sheet molding compound are greatly improved.

[0091] From the comparison of the results of Comparative Example 3 and Example 1, it can be seen that if the flame-retardant epoxy resin is replaced with a conventional resin when preparing the forged aramid sheet molding compound, the flame retardant properties of the forged aramid sheet molding compound will be significantly reduced. The conventional resin is more likely to burn when exposed to fire, while the flame-retardant epoxy resin is not easy to burn when exposed to fire and will extinguish itself when away from the fire.

[0092] From the comparison of the results of Comparative Example 4 and Example 1, it can be seen that when preparing forged aramid sheet molding compound, when the surface of aramid fiber, aramid colored yarn and aramid woven cloth has not been treated with sizing and activation, the obtained forged sheet molding compound is easy to delaminate when bent. This is because the surface of the aramid fiber that has not been activated is smooth and inert, and the interface bonding ability with the matrix resin is poor. The matrix resin is difficult to achieve effective bonding to the fiber surface. Under the action of external force, the interface failure between the aramid fiber and the matrix resin and between the aramid prepreg layers is more likely to occur, making the prepared sheet molding compound easier to delaminate under the action of external force, and the mechanical properties are reduced.

[0093] From the comparison of the results of comparative example 5 and example 1, it can be seen that if the sizing agent is replaced with a conventional waterborne polyurethane resin when preparing the forged aramid sheet molding compound, the mechanical properties of the forged aramid sheet molding compound will be significantly reduced, and stratification will easily occur. The sizing agent used in the present invention contains a water-soluble polyamide resin, which is more conducive to improving the interlayer bonding strength and the mechanical properties of the final product, because the polyethylene glycol segment and polyetheramine D400 in the water-soluble polyamide resin molecule enhance the polarity matching and wettability with the epoxy resin, and the molecular structure of the water-soluble polyamide resin is similar to that of aramid fiber, which also enhances the polarity matching and wettability with the aramid fiber. In addition, when cured at high temperature, the Tg of the polyamide is greater than 180°C (significantly higher than the Tg of the polyurethane), which avoids interface slip and improves the interlayer shear strength.

[0094] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0095] For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, all of which belong to the protection scope of the present invention. The protection scope of the present invention shall be based on the attached claims.

Claims

1. A forged aramid sheet molding compound, characterized in that: The forged texture aramid sheet molding compound comprises aramid colored silk unidirectional prepreg, aramid fiber unidirectional prepreg, aramid woven cloth prepreg and flame retardant epoxy resin; Aramid colored yarn, aramid fiber and aramid woven fabric are sizing treated respectively, and then impregnated with flame retardant epoxy resin to obtain the aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; The sizing agent used in the sizing treatment includes a water-soluble polyamide resin prepared by polymerizing α,ω-dicarboxyl polyethylene glycol and polyether amine.

2. The forged aramid sheet molding compound according to claim 1, characterized in that: The width of the aramid colored yarn unidirectional prepreg is 15-20 mm; The aramid colored yarn unidirectional prepreg is composed of one or more colors of three primary colors, namely red, yellow and blue, and colors mixed by the three primary colors.

3. The forged aramid sheet molding compound according to claim 1, characterized in that: The aramid fiber unidirectional prepreg is made of primary color aramid fiber unidirectional tape impregnated with flame retardant epoxy resin; The aramid woven fabric prepreg is prepared by sizing and impregnating one or more of aramid plain fabric and aramid twill fabric with flame retardant epoxy resin.

4. The forged aramid sheet molding compound according to claim 1, characterized in that: The preparation method of the water-soluble polyamide resin comprises the following steps: adding pyridine, triphenyl phosphite, calcium chloride and lithium chloride into N-methylpyrrolidone, stirring to completely dissolve the calcium chloride and lithium chloride, then adding polyetheramine and α,ω-dicarboxyl polyethylene glycol into the system, heating and stirring until the system becomes completely clear, heating under the protection of inert gas to carry out polymerization reaction, and obtaining the water-soluble polyamide resin through post-treatment after the reaction is completed.

5. The forged aramid sheet molding compound according to claim 1, characterized in that: The sizing agent is prepared by dissolving a water-soluble polyamide resin in water to prepare an aqueous solution with a concentration of 5-10wt%, and then adding a wetting agent in an amount of 0.1-0.2% by weight of the aqueous solution to the aqueous solution.

6. A method for preparing a forged aramid sheet molding compound according to any one of claims 1 to 5, characterized in that: The preparation method is: S1, sizing aramid fiber, aramid colored yarn and aramid woven fabric, and then respectively impregnating them with flame retardant epoxy resin to obtain aramid colored yarn unidirectional prepreg, aramid fiber unidirectional prepreg and aramid woven fabric prepreg; S2, cutting the aramid colored yarn unidirectional prepreg into chopped fiber bundles, evenly spreading the chopped fiber bundles on the aramid fiber unidirectional prepreg, and then pressing to obtain a forged textured aramid fiber prepreg; S3, laying the forged texture aramid fiber prepreg and the aramid woven fabric prepreg on the mold cavity surface in sequence, and then laying the isolation film, breathable felt, and vacuum bag in sequence, and pressing in the flame-retardant epoxy resin by vacuuming to obtain a composite material; S4, heating and pressurizing the entire mold after the composite material is laid in step S3 to achieve curing and molding to obtain the forged aramid sheet molding compound.

7. The method for preparing a forged aramid sheet molding compound according to claim 6, characterized in that: In step S2, the length of the chopped fiber bundle is 20 mm-40 mm; the thickness of the chopped fiber bundle spread on the aramid fiber unidirectional prepreg is 0.5 mm-1.5 mm.

8. The method for preparing a forged aramid sheet molding compound according to claim 6, characterized in that: In step S2, the pressing conditions are: temperature 145-155°C, pressure 1.0-2.0 MPa, and time 60-120 min.

9. The method for preparing a forged aramid sheet molding compound according to claim 6, characterized in that: The amount of the flame retardant epoxy resin used accounts for 30%-40% of the total mass of the forged aramid sheet molding compound.

10. The method for preparing a forged aramid sheet molding compound according to claim 6, characterized in that: In step S4, during the curing process, the injection pressure is 0.1-1.0 MPa; the heating is gradient heating, and the gradient heating process is: from room temperature, at a heating rate of 4-5°C / min, the temperature is increased to 100±2°C, and then kept warm for 20-30min; then at a heating rate of 4-5°C / min, the temperature is continued to be increased to 145±5°C, and kept warm for 100-120min.

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