RU2321606C1 - Method of production of prepreg - Google Patents

Abstract

FIELD: production of prepreg on base of cores of carbon, glass and organic fibers or their combination, as well as fabrics of various interweaving for manufacture of transport facilities, aircraft and spacecraft.

SUBSTANCE: proposed method includes first impregnation of filler in first bath filled with 5- 20-% solution of polymer binder preheated to temperature of 25-30 C at impregnation rate of 0.45-1.5 m/min when filler is acted on by supersonic waves. Then drying is carried out with the aid of infra-red radiation at filler flow rate of 0.45-1.5 m/min. Second impregnation of filler is carried out in second bath filled with 49- 65-% solution of the same polymer binder preheated to temperature of 25-30 C at impregnation rate of 0.45-1.5 m/min under action of ultrasonic waves. Then, filler is dried at rate 0.45-1.5 m/min flowing through horizontal drying chamber at temperature which is below gelatinization temperature of binder by at least 20 C. Then, partially dried filler is passed through system of drawing heated and cooled calendars.

EFFECT: improved quality of impregnation of prepreg.

7 cl, 2 tbl, 5 ex

Description

The invention relates to the field of producing prepregs on the basis of bundles of carbon, glass, organic fibers or any combination thereof, as well as fabrics of various weaving based on them, used for the manufacture of articles of transport, aerospace and other purposes.

A known method of producing a carbon fiber prepreg based on the continuous impregnation of a carbon fiber filler with a polymer binder after passing an electric current through a segment of a carbon fiber filler moving between the electrodes with the complete removal of water adsorbed from the environment, process lubricant and surface contaminants (RU, No. 2162864, class C08J 5/06, published on October 20, 2000).

The disadvantage of this method is that it is not applicable for the manufacture of prepregs, the fillers of which are fibers having dielectric properties, for example glass fibers or organic fibers, since they are not electrically conductive and do not form an electric arc. This method is not applicable to carbon fillers treated with an active lubricant to activate the surface of the carbon filler and increase the adhesive properties of the filler, since it is removed together with moisture.

There is also known a method of manufacturing prepregs, in which a solvent-free thermosetting resin-based liquid composition is applied to a sheet material coated with a release agent, after which the sheet material is applied to a substrate and the resulting assembly is heated, transferring the composition to the substrate, and then solidified to B -stages (JP, No. 4-6525 B4, class B29B 11/16, publ. 02/06/1992).

The disadvantage of this method is the impossibility of using it in the manufacture of prepregs, which use binders containing solvent, as well as tows and fabrics of thick denominations that cannot be uniformly impregnated in thickness. Highly concentrated binders do not have the same fluidity as solvent containing binders. They impregnate the tows only superficially, “locking” the air between the fibers that make up the tow.

Closest to the proposed method for the manufacture of the prepreg is a method that involves impregnating a glass fiber substrate with a solvent, impregnating a solvent impregnated glass fiber substrate with an epoxy resin, heating the glass fiber substrate impregnated with epoxy resin, further impregnating the glass fiber substrate impregnated with epoxy resin impregnated with epoxy resin wherein the epoxy resin is already partially cured, and heating the resulting glass fiber substrate impregnated with the epoxy resin. The method is characterized in that the degree of polymerization of the epoxy resin in the inner layer is 85% or more, and in the outer layer the degree of polymerization of the epoxy resin is 65% or less (EP, No. 1241208 A1, class C08J 5/24, published on September 18, 2002 g., prototype).

The disadvantage of this method is that it cannot be applicable in the manufacture of prepregs, in which fillers are used bundles of carbon, glass, organic fibers treated with active sizing, as well as fabrics based on these fibers, since when these fillers are impregnated with solvents used in the prototype, active lubricants designed to improve the adhesive properties between the filler and the binder used are unevenly removed from the surface of the filler for impregnation of the filler. In addition, due to the different degrees of polymerization of the epoxy resin in the inner and outer layers of the prepreg, a zone of additional stress arises, which leads to weakening of cohesive and adhesive bonds, which negatively affects the quality of the prepared prepreg. All this does not allow to obtain a prepreg with a given level of characteristics.

The objective of the invention is to develop a method of manufacturing a prepreg from a solution impregnated with a polymer binder, bundles of carbon, glass, organic fibers, or combinations thereof, as well as fabrics of various weaving, made on the basis of these bundles, and allowing to obtain a prepreg with a given level of performance.

The technical result is achieved in that in a method for manufacturing a prepreg, comprising first impregnating a filler with a polymer binder solution, drying an impregnated filler, a second impregnating a filler with a solution of the same polymeric binder, drying an impregnated filler in a drying chamber, according to the invention, the first filler impregnation is carried out 5-20% a solution of a polymer binder, heated to a temperature of 25-30 ° C, with an impregnation speed of 0.45-1.5 m / min when exposed to the filler by ultrasonic waves. Drying of the filler after the first impregnation is carried out by infrared radiation while passing it at a speed of 0.45-1.5 m / min. The second impregnation of the filler is carried out with a 49-65% solution of the same polymer binder, heated to a temperature of 25-30 ° C, with a speed of impregnation of 0.45-1.5 m / min when exposed to the filler with ultrasonic waves. Drying of the filler after the second impregnation is carried out when it passes at a speed of 0.45-1.50 m / min through a horizontal drying chamber at a temperature below the gelatinization temperature of the binder by at least 20 ° C. Then, the dried filler is passed through a system of pulling heated and cooled calendars to obtain the nominal thickness of the prepreg and to ensure the total amount of polymer binder.

In this case, bundles of carbon, glass, organic fibers or any combination, as well as fabrics of various weaving made of bundles based on carbon, glass, organic fibers or any combination thereof, can be used as filler.

The influence of ultrasonic waves during the impregnation of the filler with a polymer binder solution is advisable to perpendicular to the location of the fibers in the bundle when the filler directly touches the waveguide located in the binder bath. In this case, the parameters of the effect of ultrasonic waves during the impregnation of the filler with a polymer binder solution can have the following values: the ultrasound frequency is 19.5-20.5 kHz, the vibration amplitude is 1.5-3 microns, and the ultrasonic vibration power is 300 W. The temperature in the impregnation zone should not exceed 60 ° C.

Drying the filler with infrared radiation after its first impregnation with a polymer binder solution can be carried out at a temperature not exceeding the boiling point of the polymer binder solvent.

It is advisable to pass the filler in the form of a bundle before the second impregnation with a polymer binder solution through a folding rotary device so that the distance between the centers of the bundles when laying on the rotary device is equal to the width of the rolled bundle.

The drawing shows the installation diagram for the preparation of the prepreg: 1 - creel crest, 2 - bobbin holders for bobbins with a bundle, 3 - distribution comb, 4 - tissue attachment device, 5 - unwinding device for fixing the release liner, 6 - first impregnation bath, 7 - device for drying the prepreg with infrared radiation, 8 - folding swivel device, 9 - second impregnation bath, 10 - first heated impregnation tank, 11 - second heated impregnation tank, 12 - tension unit, 13 - lamination calendar, 14 - horizontal the first chamber for drying the filler after the second impregnation; 15 — heated and cooled calendars; 16 — receiving device for the obtained prepreg.

A method of manufacturing a prepreg based on a bundle consisting of carbon, glass, polymer fibers, or combinations thereof, is as follows: the bundles from the bobbin holders 2 of the creel 1 enter the distribution comb 3, in which they are evenly distributed across the width and enter the first impregnation bath 6 s a solution of a polymer binder of 5-20% concentration, which is supplied from the first heated impregnation tank 10. Impregnation is carried out by exposure to the filler with ultrasonic waves when touched by a tow wave ode perpendicular arrangement of fibers in a bundle with the amplitude of oscillation of 1.5-3.0 microns, the frequency of ultrasonic vibration 19,5-20,5 kHz and power of ultrasonic vibrations 300 watts. The impregnated filler enters the device 7 for drying by infrared radiation. The drying temperature does not exceed the boiling point of the solvent of the polymer binder. Next, the impregnated harness enters the folding swivel device 8, in which the harness is expanded so that the distance between the centers of the harness is equal to the width of the rolled harness. In the second impregnation bath 9, the dried filler is impregnated with a 49-65% polymer binder solution when exposed to ultrasonic waves when the waveguide touches the waveguide perpendicular to the location of the fibers in the bundle with an ultrasonic vibration frequency of 19.5-20.5 kHz; the oscillation amplitude of 1.5-3 microns and the power of ultrasonic vibrations of 300 watts. The binder solution enters the bath from the second heated tank 11. Then, the impregnated filler is placed on a release liner, which is wound from the unwinding device 5 and enters the horizontal drying chamber 14. In this case, the drying temperature of the impregnated filler is reduced by at least 20 ° C. From the horizontal drying chamber 14, the dried filler passes through a system of pulling heated and cooled calendars 15 to obtain a nominal prepreg thickness and an optimal total polymer binder deposit. The finished prepreg arrives at the receiving device 16, previously dissolved along the length of the prepreg to the desired width. The process of impregnation and drying of the filler is carried out at a speed of 0.45-1.5 m / min.

A method of manufacturing a prepreg based on fabrics of various weaving, made of bundles based on carbon, glass, organic, polymer fibers or various combinations thereof, is as follows: the fabric from the unwinding device 4 enters the first impregnation bath 6, which is fed from the first impregnated heated tank 10 polymer binder solution of 5-20% concentration. After the first impregnation, carried out when exposed to ultrasonic waves when the filler touches the waveguide located in the impregnation bath, when exposed to ultrasonic waves, perpendicular to the fibers in the tow of which the fabric is made, at a frequency of ultrasonic vibrations of 19.5-20.5 kHz, the power of ultrasonic vibrations of 300 W and an oscillation amplitude of 1.5-3.0 μm, the impregnated fabric is dried by infrared radiation in the device 7. The temperature in the drying zone should not exceed the boiling point of the polymer solvent binder. The dried fabric enters the second impregnation bath 9 with a 49-65% solution of the polymer binder 9, which is supplied from the second heated tank 11. The concentration of the binder in the second impregnation is 49-65%. Further, the prepreg manufacturing process is similar to the harness-based prepreg manufacturing process described above.

The inventive method of impregnation allows to obtain a prepreg with the required parameters, regardless of the thickness of the fibrous filler in the form of a bundle or fabrics based on it, such as filler and polymer binder, as well as the width of the fabric.

Example 1. The carbon harness "Grapan-27" TU 1916-204-51385208-2001 from the bobbin holders of the creel goes to the distribution comb and then to the first impregnation in the first bath. The solution of the epoxy modified binder "ENFB" TU 1-596-36-98 5% concentration comes from the first heated tank having a constant temperature equal to 25 ° C. The first impregnation of the filler is carried out in an ultrasonic field at a frequency of 20.5 kHz, an amplitude of 2.0 μm and an ultrasonic vibration power of 300 W. The temperature in the zone of impregnation of the tow is 30 ° C. The impregnated tow is fed into the device for drying with infrared radiation to remove the solvent of the alcohol-acetone mixture. The temperature in the drying zone for this solvent is 70 ° C. Then, after the first impregnation, the tow is dried and fed to the folding rotary device. The distance between the centers of the bundles is 10 mm. From the folding rotary device, the dried tow is fed to the second impregnation in the second bath with the same modified epoxy binder of 49% concentration coming from the second heated tank having a constant temperature of 25 ° C. The parameters of exposure to ultrasonic waves and the temperature are the same as during the first impregnation in the first impregnation bath. The impregnated tow is laid on release paper and fed into a horizontal drying chamber. The temperature in the drying chamber is 90 ° C. From the drying chamber, a prepreg, laid between two release papers, passes through a calendaring system. Clearance on calendars is maintained in the range of 0.25-0.33 mm; the temperature of the calendars must not exceed the temperature in the drying chamber. The speed of impregnation and drying is 1 m / min. Technological parameters are shown in table 1, physico-chemical parameters of the prepreg are shown in table 2.

Example 2. Combined fabric 4510 of Porcher industries based on carbon fibers, fiberglass from the unwinding device enters the first impregnation bath, into which from the first heated tank an epoxy modified binder of ENFB of 10% concentration with a constant temperature of 25 ° C. The first impregnation is carried out in an ultrasonic field with an ultrasound frequency of 19.5 kHz, an oscillation amplitude of 1.5 μm and an ultrasonic oscillation power of 300 W. The temperature in the impregnation zone is 30 ° C. After impregnation, the fabric enters the dryer for drying with infrared radiation at 70 ° C and in the second impregnation bath for the second impregnation. In the future, the process proceeds as in example 1. The impregnation parameters are presented in table 1, physico-chemical parameters are presented in table 2.

Example 3. The carbon fabric 3692 of the company "Porche industries" based on carbon fibers is impregnated according to example 2. The impregnation parameters are presented in table 1, physicochemical parameters of the prepreg are shown in table 2.

Example 4. Fiberglass TR-0.56-117A (TU 5952-060-0.5763895-2003) from the unwinding device enters the first impregnation bath for the first impregnation. The phenolic binder BFOS (TU 1-596-113-81) of 20% concentration enters the bath from a heated tank with a stable temperature of 25 ° C. The impregnation process is similar to example 2. The impregnation parameters are shown in table 1. The physicochemical parameters of the prepreg are shown in table 2.

Example 5. Polymeric fabric of CBM, art. 56313N (TU 17VNIIIPKHV-350-88) is impregnated with an EP-2MK epoxy polyisocyanate binder (TU 1-596-66-86) according to Example 2. The impregnation parameters are shown in Table 1. The physicochemical parameters of the prepreg are presented in Table 2.

From the above examples 1-5 and tables 1 and 2 it is seen that the proposed method allows to obtain a prepreg based on a solution of polymer binder impregnated bundles of carbon, glass, organic fibers or combinations thereof, as well as fabrics of various weaving, made on their basis, with given level of characteristics.

Table 1 Technological parameters of the preparation of the prepreg No. p / p Technological parameters Carbon harness Grapan-27 Combine. fabric 4510 Carbon fabric 3692 Fiberglass TR-0.56-117A Polymer fabric CBM 56313N one 2 3 four 5 6 7 one Technical paper TU 1916-204-5138 5208-2001 "Porcher inddustries" Porcher industries TU 5952-060-0576389 5-2003 TU 17VNIIIPHV-350-88 2 Polymer binder Epoxy binder ENFB ENFB ENFB Phenolic Binder BFOS Epoxy polyisocyanate binder EP-2MK 3 Technical paper TU 1-596-36-98 TU 1-596-36-98 TU 1-596-36-98 TU 1-596-113-81 TU 1-596-66-86 four The concentration of the binder in the first bath,% 5 10 10 twenty 5 5 The concentration of the binder in the second bath,% 49 51 fifty 65 49 6 Infrared temperature, ° С 70 70 70 76 67 7 Binder temperature, ° С thirty thirty thirty 25 25 8 The frequency of ultrasound, kHz 20.5 19.5 19.5 20,0 20.5 9 Amplitude of vibrations, microns 2.0 1,5 1,5 2.0 3.0 10 Power of ultrasonic vibrations, W 300 300 300 300 300 eleven Impregnation, drying speed, m / min 1,0 0.65 0.5 1,5 1.4 12 Temperature in the drying chamber, ° С 90 90 90 110 70 13 Temperature on calenders, ° С 90 90 90 110 70 fourteen Clearance on calenders, mm 0.25-0.33 0.5-0.55 0.47-0.5 0.5-0.8 0.15-0.25

table 2 PHYSICAL AND CHEMICAL INDICATORS No. p / p Name and characteristics of the filler material TU requirements Actual figures mass fraction of binder,% mass fraction of volatiles,% mass fraction of binder,% mass fraction of volatiles,% one Grapan-27 (Russia). Carbon fiber roving with a filament count of 12,000 and a linear density of 740 tex 41-47 no more than 2 42-43 less than 1.5 2 Fabric carbon fiber based 4510 and weft fiberglass 39-46 no more than 3 42-43 less than 1.5 3 Fabric 3692 based on carbon fiber warp and weft 38-42 no more than 3 40-41 less than 1.5 four Fiberglass TR-0.56-117A 44-50 no more than 5 45-46 less than 2 5 Polymer fiber based CBM fabric 42-52 no more than 4 45-46 less than 2

Claims (7)

1. A method of manufacturing a prepreg, comprising first impregnating the filler in the bath with a polymer binder solution, drying the impregnated filler, a second impregnating the filler in the bath with a solution of the same polymeric binder, drying the impregnated filler in the drying chamber, characterized in that the first filling of the filler is carried out in the first bath 5 -20% solution of a polymer binder, heated to a temperature of 25-30 ° C, with a speed of impregnation of 0.45-1.5 m / min when exposed to ultrasonic waves on the filler, drying the filler after the first the impregnations are carried out by infrared radiation while passing it at a speed of 0.45-1.5 m / min, the second impregnation of the filler in the second bath is carried out with a 49-65% solution of the same polymer binder, heated to a temperature of 25-30 ° C, at a speed impregnation of 0.45-1.5 m / min, when exposed to ultrasonic waves, and the filler is dried after the second impregnation by passing it at a speed of 0.45-1.5 m / min through a horizontal drying chamber at a temperature below the gelation temperature of the binder is not less than 20 ° C, after which dried the fill is passed through a system of pulling heated and cooled calendars. 2. A method of manufacturing a prepreg according to claim 1, characterized in that the filler is used bundles of carbon, glass, organic fibers or any combination thereof. 3. The method of manufacturing the prepreg according to claim 1, characterized in that as a filler using fabrics of various weaving, made of bundles based on carbon, glass, organic fibers or any combination thereof. 4. A method of manufacturing a prepreg according to claim 2 or 3, characterized in that the action of ultrasonic waves when the filler is impregnated with a polymer binder solution is perpendicular to the location of the fibers in the bundle when the filler directly touches the waveguide located in the impregnation bath at a temperature in the impregnation zone of not higher than 60 ° C. 5. The method of manufacturing the prepreg according to claim 1, characterized in that the parameters of the action of ultrasonic waves when the filler is impregnated with a polymer binder solution have the following values: ultrasound frequency 19.5-20.5 kHz, vibration amplitude 1.5-3.0 μm, power of ultrasonic vibrations 300 W. 6. The method of manufacturing the prepreg according to claim 1, characterized in that the filler is dried by infrared radiation after the first impregnation is carried out at a temperature not exceeding the boiling point of the polymer binder solvent. 7. The method of manufacturing the prepreg according to claim 2, characterized in that the bundle before the second impregnation is passed through a folding rotary device so that the distance between the centers of the bundles during layout on the rotary device is the width of the rolled bundle.