The specific embodiment
As depicted in figs. 1 and 2, the priming by vacuum method of p-aramid fiber composite product of the present invention is with flexible vacuum bag film coated, sealing fibre reinforced materials on the single face rigid die, then under negative pressure of vacuum, get rid of the gas in the die cavity, utilize flowing of resin, infiltration realizes the dipping to fiber and fabric thereof, and under room temperature or heating condition a kind of method method of curing molding.Fig. 3 is the flow chart of the method for the invention, and described method comprises the steps:
One, cleaning mould 1
The material of making mould 1 has multiple, should be selected according to specific product size, shape and access times.This method adopts stainless steel mould 1.If mould 1 is comprised of polylith, then need to fit together, note the assembling location, can not be excessive to the die slot crack, available adhesive tape seals in case of necessity, prevents the gummosis mucous membrane, and relevant knock-outs will will install, and jacking block is set level.
Mould 1 is stained with the cull that last time, the demoulding was left over, carefully roots out with flat chisel, can not damaging surface, polyvinyl alcohol (PVA) releasing agent can wash by water, and then dries stand-by.
Two, brushing releasing agent
The releasing agent that the present invention adopts is the PVA(polyvinyl alcohol) releasing agent.The PVA releasing agent is that water or the ethanolic solution of PVA is formulated, can be on mould 1 film forming.
When carrying out the preparation of releasing agent, water is heated to 60 ~ 70 ℃ first, add while stirring the PVA powder, and insulated and stirred is to fully dissolving.Cool to room temperature stirs and drips at a slow speed ethanol, prevents caking.Filtration after finishing except degranulation and impurity, adds proper quantity of defoaming agent at last, the dress Gutter.
When carrying out the brushing of releasing agent, with hairbrush or polyurethane foams piece dipping PVA releasing agent, attention can not suck air, produces bubble, then in mould 1 surface uniform brushing.With the dynamics of hand control brushing thickness, brushing is many and bad, brushes thickness and is preferably 0.2mm, can not holiday, and can not produce current mark and in groove, gather.Prevent during brushing that hair and winged insect from falling on the surface.Dry about 30min after having brushed, can use after the bone dry film forming.But when it is cold drying time longer, about 0.5 ~ 1 hour.Brushing is will note evenly brushing the improper minute bubbles that have.
If the PVA releasing agent resting period is long, when viscosity increases, can add an amount of water or ethanol and dilute again usefulness, can filter again usefulness, not impact effect if any impurity.
If room temperature is low, drying time, available hair-dryer was air-dry, but prevents that dust from falling into when long.Summer is the brushing releasing agent under light, have on the film cover, prevents that mosquito from falling into.
Remove the method for releasing agent and namely clean with running water, necessarily avoid with the flat chisel cleaning, in order to avoid scratch mould 1.
Three, preparation resin glue
1, resin glue I: adopt 100 parts of unsaturated polyester resins, 2 parts of initator methyl ethyl ketone peroxides, 1 ~ 4 part of promoter cobalt naphthenate or naphthoic acid cobalt, 2.5 ~ 3.5 parts of anti-caking agent aerosils, 2 ~ 3 parts of defoamers, 8 ~ 10 parts of pigment paste preparations.When preparation resin glue I adds pigment paste, the materials of a cover product or a collection of product once should be allotted, in order to avoid color to occur inconsistent because repeatedly preparing.Described umber is mass fraction.
2, resin glue II: adopt 100 parts of unsaturated polyester resins or epoxy resin, 5 ~ 10 parts of diluent acetone, 1 ~ 3 part of initator methyl ethyl ketone peroxide, 4 ~ 6 parts be promoter styrene solution, 10 ~ 20 parts of talcum powder preparations as filler of 8% ~ 10% that the dimethylaniline of 1:1 and benzoyl peroxide are made into by mass ratio.Described umber is mass fraction.
3, join glue
Join the glue instrument and comprise Plastic Drum, plastic tub, plastic cup, graduated cylinder, stirring rod, agitator etc.Preparation is during glue, and the quantity of preparation is used basin, manual stirring on a small quantity by product consumption and the consumption preparation that once pastes; A large amount of resin glues then need be used drum, and agitator stirs and can use.Join after the glue at every turn, should take out 10 ~ 20 grams and do sample gelling experiment, observe its gelling time, prevent from solidifying too fast or excessively slow.
Promoter, curing agent are metered into graduated cylinder respectively when joining glue, and once can only add a kind ofly, can add the second after stirring, and react to each other otherwise two kinds of auxiliary materials can occur, and burning and blast occur.If there is filler to add in the glue, then need often to stir, in order to avoid the filler precipitation.
The consumption of promoter is regulated from 1% ~ 4% voluntarily with the variation of weather, and the sky can add 6% at most when cold.
Curing agent can only add in proportion, can not arbitrarily increase and decrease.
The epoxy resin operating period is short, if adopt epoxy resin preparation resin glue, once can only prepare on a small quantity.
Four, make gel coating resin 2
The quality of gel coating resin 2 directly affects the presentation quality of product, and therefore, it is very crucial selecting high-quality gel coating resin and pigment paste and adopting correct brushing method.
Gel coating resin 2 adopts the resin glue I.
The brushing method that the present invention adopts is with hairbrush the resin glue I for preparing to be brushed equably on mould 1 surface, and the glue consumption of resin glue I is 500g/m
2, namely gel coat thickness is at 0.4 ~ 0.5mm, and gel coat cold curing 1 hour reaches tactile dried rear stand-by.The general fiberglass brush special that adopts during brushing, common hairbrush easily falls hair, and it is even try one's best during brushing, and hairbrush should not be brushed back and forth repeatedly, can not holiday, can not produce trace, can not gather.This method is adopted at home in a large number, abroad then seldom.Inhomogeneous because brushing, efficient is low.But to some complex structures, the goods that are difficult for brushing still must adopt.
Five, make superficial layer 3
The superficial layer 3 of p-aramid fiber composite is to make of the fiberglass surfacing mat laying.Superficial layer 3 can prevent that gel coat from appearing woven design, makes the surface form resin-rich layer, thereby the anti-seepage of product, corrosion resistance are further improved.
Make superficial layer 3 and adopt resin glue II and fiberglass surfacing mats, described fiberglass surfacing mat is that glass chopped strand mats is cut out, laid and form.
When making superficial layer 3, because being everlasting, uses in the atmosphere p-aramid fiber/epoxy composite material, the effect of sunshine especially ultraviolet light can make the mechanical property of composite that to a certain degree variation occurs.Ultraviolet luminous energy causes many chemical reactions, makes macromolecular material generation oxidation and degraded, and these reactions often are chain reactions, and is subjected to the adding of the conditions such as temperature, oxygen, humidity and accelerates.Therefore, need in the resin glue II, add ultra-violet absorber, perhaps outside superficial layer 3, be coated with UV resistant paint, thereby prolong the service life of p-aramid fiber/epoxy composite material.
When carrying out the making of superficial layer 3, at first glass chopped strand mats is pressed mould 1 surface size cutting, the surface is 30g/m with substance
2Or 50g/m
2Chopped felt for well, it is layered on the gel coat face, with a hair roller gluing, then use the deaeration of deaeration roller, strictly control does not have bubble.If the dell or the dead angle that are difficult for making are arranged, usable resins putty is filled and led up first.The glue content of superficial layer 3 should be controlled at 85% ~ 95%.
Six, make enhancement layer 4
Enhancement layer 4 is important bearing beds of composite product, plays a part to guarantee structure and the intensity of product.Enhancement layer 4 comprises para-aramid fiber cloth, glass chopped strand mats and twin beams bracing means 10, is filled with Sandwich materials between the twin beams of described twin beams bracing means 10.Can be according to size, shape, the stressing conditions of p-aramid fiber composite product, design twin beams bracing means 10.As required para-aramid fiber cloth and the glass chopped strand mats of selecting carried out the adaptability cutting, adapt if be used for 10 of coating twin beams bracing means and twin beams bracing means 10, if for then adapting with mould 1 on the superficial layer 3 that directly is layed in mould 1.
Para-aramid fiber cloth will boil 20min before the usefulness in 80 ~ 90 ℃ water.After p-aramid fiber carries out surface treatment, removed the oil stain of fiber surface herein, increased the adhesion of aramid fiber and resin, can realize the bonds well of p-aramid fiber and resin glue, made it obtain stable, good properties.
The concrete making step of enhancement layer 4 is as follows:
1. make twin beams bracing means 10;
Described twin beams bracing means 10 profiles are " II " shape, the employing wet process forming method is made, described wet process forming method is to paste first interior adventitia, again interior adventitia is combined, then in die cavity, pour into the hard polyurethane foams foamed plastics, foamed solidification, finally demould namely become the foam layer product.Described twin beams bracing means wet process forming method flow process as shown in Figure 4, described method is specially: at first paste interior adventitia, with described interior adventitia combination; Select the selection of suitable foamed material; Be under 20 ~ 30 ℃ of conditions in temperature, perfusion hard polyurethane foams foamed plastics in the die cavity; Last foamed solidification and the demoulding form goods.Wherein, should be noted that have following some:
A. the selection of foam material
Hard polyurethane foams item kind is a lot, and general producer all is made into it A, B two parts are sold, and wherein the A component is the PIC class, and the B component is the mixture of polyethers or auxiliary material.
In the auxiliary material, comprise blowing agent F-11, foaming agent silicone oil, the cooperation of the multiple materials such as curing agent triethylamine etc. and fire retardant forms.The kind of isocyanates and polyethers is different, and the foamy body of made is also different.
Wherein the consumption of F-11 determines the density of foam.So the selection of foam should be ordered to producer according to the specification requirement of product.B. pour into the consumption of foam and the speed of perfusion
When pouring into foaming machine, general proportioning is A:B=1:1.
The total consumption of foam is that the density with foam, the stereometer of mould 1 cavity are calculated, and consumption is crossed conference and caused the bad mould 1 that overflows or expand, and I haven't seen you for ages excessively hollow occurs or lack material.Because the lather quickness of foam material and the relation of curing rate, rate of flooding should be grasped suitably, avoids occuring the heartburn or avalanche phenomenon of foam.
The scene temperature of C. pouring into
Should 20 ~ 30 ℃ best, because temperature is too low, be difficult to bubble, need carry out mould 1 or feed liquid preheating, automatically volatilization of F-11 in the excess Temperature feed liquid.
D. the requirement of mould 1
Produce very large pressure during because of foaming, thus mould 1 thickening required, and enough rigidity is arranged, simultaneously location, assembling mechanism should be arranged.Answer coating release agent on the mould 1.
E. the design of perfusing hole, steam vent
Perfusing hole should allow feed liquid from pour into the bottom, bubble in the bottom.The gas outlet, the flash mouth is located at top.
In a word, note above main points, make its uniform in foaming, interlaminar bonding is firm, does not lack material, hollow just can not made satisfactory foam layer product.
2. select suitable para-aramid fiber cloth, glass chopped strand mats, cut out;
The material of enhancement layer 4 should be chosen in advance according to the specification requirement of product.The type of used glass chopped strand mats, p-aramid fiber woven roving, the trade mark of thickness and used resin, kind etc. all will strictly be checked before pasting, in order to avoid will expect to cause unnecessary loss with wrong.
A. the fabric dividing platform needs the fabric dividing platform of a proper area, and p-aramid fiber cloth is layered on the cutting of taking measurements on the table top.The width of para-aramid fiber fabric is 1.7m, thus platform wide be that 2.0m is more suitable.Put on dimension line on the table top.Yardage roll can be placed on the fabric dividing frame rotate use more convenient.
B. the fabric dividing instrument mainly is ruler, 526-H aramid fiber scissors and fabric dividing cutter.Ruler can be used Steel Ruler, wooden rule, box chi.Woollen goods scissors, common scissors can be adopted for glass chopped strand mats, the 526-H aramid fiber scissors of Japan's manufacturing can be adopted for p-aramid fiber cloth.
C. should check first before the fabric dividing fabric dividing whether the specification of chopped felt, woven roving, thickness meet the requirements; Observe the surface whether greasy dirt, foreign material, unequal are arranged; With the feel inspection moisture absorption that whether absorbed water, if moisture absorption then need have been dried again and used.
D. cutting sets size according to area shape, cutting on platform.Selvedge is crossed obstinately and is dismissed.The available scissors of complex-shaped or monolithic.The cloth sheet that shape is single, quantity is large, particularly chopped felt can stack felt, once cut several layers with cut-off knife.
E. number the cloth of different size, can number respectively and to place, in order to avoid confusion reigned when pasting.
3. described para-aramid fiber cloth is boiled 20min in 80 ~ 90 ℃ water; After p-aramid fiber carries out surface treatment, removed the oil stain of fiber surface herein, increased the adhesion of aramid fiber and resin, can realize the bonds well of p-aramid fiber and resin glue, made it obtain stable, good properties.
4. lay successively described para-aramid fiber cloth and glass chopped strand mats to setting thickness;
Described glass chopped strand mats and para-aramid fiber cloth in layer are routed on the described superficial layer 3, repeat successively until the thickness that needs.If when running into bent angle or shaggy block, then available scissors flattens the cloth clip with hairbrush.If when mould 1 two or more than two fiber cloth of larger palpus or felt overlap, should overlap 5cm.Simultaneously, the overlap joint between every layer should stagger as much as possible.The consumption mass ratio of para-aramid fiber cloth and resin glue II is 1:1 ~ 1:1.5.The consumption mass ratio of glass chopped strand mats and resin glue II is 1:1.9 ~ 1:2.9.
5. place described twin beams bracing means at described para-aramid fiber cloth and glass chopped strand mats.
Seven, the laying of priming by vacuum device and sealing
Spreading first release cloth 5, then is flow-guiding cloth 6, is vacuum bag 7 at last, and described flow-guiding cloth also comprises mozzle or flow-guiding screen 6 times, plays drainage, and described enhancement layer 4 is infiltrated evenly.Before the vacuum bag 7 that closes, think over the trend of resin glue and vacuum-pumping pipeline, otherwise the some places resin can can't infiltrate, adopt sealing strip that described vacuum bag 7 is sealed.Want extreme care during laying, in order to avoid some sharp objects puncture vacuum bag 7.Described priming by vacuum device is connected with other equipment by tube connector 8, and the bucket 12 that resin glue is used in perfusion is equipped with in end connection, and the other end connects vavuum pump.
Eight, the priming by vacuum of resin glue 13
Resin glue 13 heats in container, stirs 3 ~ 4h under 680-700Pa vacuum, de-bubbled; To vacuumize in mould 1 die cavity, take out bubble in the most resin glue and the moisture in the fiber parison, during dipping keep the vacuum of 40-42Pa in the die cavity; Injection initial vacuum treatment system drops to the vacuum that 130-140Pa(is not more than de-bubbled with the vacuum in the die cavity), and remain to always and fill with die cavity, with the pressure of 2.1 ~ 2.7MPa resin 13 is injected die cavities; Die cavity is full of the final vacuum degree and disappears, and the goods in the 101kPa lower impressions solidify.
Nine, the curing of product
Take steam as medium, heat energy is transmitted to 13 li of resins through mould 1 backing, shell, profile, and resin glue 13 is solidified.Because the thermal conductivity of mould therefor tool 1 is better, so firing rate is very fast.So the p-aramid fiber composite product requires 270 ~ 280 ℃ of lower curing of room temperature, cold curing 20 ~ 24h gets final product.
Ten, the demoulding
The demoulding is a crucial procedure, and the quality of the demoulding is directly connected to the quality of product and effective utilization of mould 1.Certainly, the quality of the demoulding also depends on the design of mould 1; The surface smoothness of mould 1; Releasing agent and be coated with brushing effects; The technology that depends in addition the demoulding.
This method adopts qi exhaustion, be about to Special air nozzle and be contained in advance on the mould 1, valve links to each other with air pump by sebific duct, passes through valve during the demoulding, in the adhesive surface slit with the high pressure gas press-in die 1 of 390 ~ 680kPa and product, along with constantly entering of high pressure gas can eject product.Can hammer tapped pore place into shape with skin when suppressing, gas is entered rapidly.This release method is very effective to the large tracts of land shell product.
Must not firmly beat mould 1 with hard hammer during the demoulding, split because easy gel coating resin 2 with product and mould 1 shakes.
11, girth member and connector is fixing
In the p-aramid fiber composite product, particularly massive article need to add various skeletons, to improve stressed ability.In addition, also have many connectors need to be embedded in the composite product, the pre-buried of these parts all pastes in enhancement layer 4 back.
According to size, shape, the product stressing conditions of composite product, the girth member of design goods, material can be PVC foam, polyurethane foam or metal material.Pass through above-mentioned steps, obtain respectively former and the formpiston of product to the demoulding from the cleaning of mould 1, between described former and formpiston, paste fixing described girth member and connector, paste and frontly with resin glue putty girth member and connector are bonded at the inner face of the enhancement layer 4 of described former and formpiston, coat again after cured; Metal connecting piece will be noted the location of connecting hole, if any screw, then should seal, and opens after the curing again, prevents that solation from advancing screw.
12, post processing
(1) cut edge: the p-aramid fiber composite product need to excise burr.Behind product stripping and fixing described girth member and the connector,, add water during cutting and can make otch level and smooth along the line cutting with skive, reduce dust pollution.But this method must be reserved allowance in advance, and it is skilled that cutting personnel's technology is also wanted, otherwise cut product bad easily.
(2) processing: the p-aramid fiber composite product all need be processed.Be edging, deburring, cut-out, perforate etc.
1. edging and deburring all available sanding machine the burr of hair side is destroyed, the blob of viscose of projection is tied finishing side cut, chamfering etc.
2. cutting can firmly be cut along the gel coat face with hacksaw, but saw kerf is not bright and clean, and effect is bad.Most toothless saws (also claiming the marble saw) that adopt add the water cutting, and not only cutting efficiency is high, and otch is bright and clean.
3. perforate: square hole can cut with toothless saw.The perforate more complicated of circular hole, aperture can be used electric hand drill, opens with common drill bit or diamond bit, and the Kong Douke of diameter below 20mm adopts this method.Should from the gel coat surface, use the aperture of bradawl head perforate smooth, effective during beginning during punching.
Middle shape hole, diameter be in the hole of 30 ~ 100mm, available hole making drill.Thin-wall product gets final product with metal hole-opener, and heavy wall then need be used the diamond hole making drill, but this hole making drill needs to realize ordering by size.
The perforate more than 100mm of large-scale circular hole, diameter is at first beaten many apertures with the bradawl head along the circle line, then will justify interior plate and destroy, and with little emery wheel grinding-head the polishing of circular hole wall is got final product again.
13, check and accept
The acceptance condition of each product is different, but all should comprise outward appearance, size 2 each side.So acceptance condition should be formulated by these 2 aspects.
(1) appearance surfaces is that the products appearance of gel coat should reach: any surface finish, smooth, color and luster evenly, flawless, free from admixture, no wrinkle, without bubble etc.
(2) size, weight, appearance and size, gauge, distortion size, bore size, skeleton size, press the drawing tolerance and check and accept.Monomer weight, accessory weight, overall weight are checked and accepted on request.
Embodiment one
A kind of vacuum infusion molding method of p-aramid fiber composite product, Fig. 1 and Fig. 2 are the layer structure schematic diagram of p-aramid fiber composite product of the present invention in the priming by vacuum process, as shown in Figure 3, described method comprises the steps:
One, cleaning mould 1
Adopt the Combined mould 1 of stainless steel, comprise relative former and formpiston, prepared p-aramid fiber composite product is the tabular product of rectangle.With the cull that last time, the demoulding was left over that is stained with on the mould 1, carefully root out with flat chisel, can not damaging surface; Water cleans releasing agent, dries stand-by.
Two, brushing releasing agent
Add 5 parts of polyvinyl alcohol (low molecule powdery, mean molecule quantity is 16000~20000) after 45 parts of water are heated to 60 ~ 70 ℃, insulated and stirred cool to room temperature to the complete dissolving, 50 parts of ethanol of agitation and dropping again, filtration after finishing is except degranulation and impurity.Add at last 1 part of defoamer.
At the releasing agent that stainless steel mould 1 surface uniform brushing prepares, dry 30min after having brushed with hairbrush, stand-by behind the drying and forming-film.
Three, preparation resin glue
1, resin glue I: adopt 100 parts of unsaturated polyester resins, 2 parts of initator methyl ethyl ketone peroxides, 1 ~ 4 part of promoter cobalt naphthenate or naphthoic acid cobalt, 2.5 ~ 3.5 parts of anti-caking agent aerosils, 2 ~ 3 parts of defoamers, 8 ~ 10 parts of pigment paste preparations.When preparation resin glue I adds pigment paste, the materials of a cover product or a collection of product once should be allotted, in order to avoid color to occur inconsistent because repeatedly preparing.Described umber is mass fraction.
2, resin glue II: adopt 100 parts of unsaturated polyester resins or epoxy resin, 5 ~ 10 parts of diluent acetone, 1 ~ 3 part of initator methyl ethyl ketone peroxide, 4 ~ 6 parts be promoter styrene solution, 10 ~ 20 parts of talcum powder preparations as filler of 8% ~ 10% that the dimethylaniline of 1:1 and benzoyl peroxide are made into by mass ratio.Described umber is mass fraction.
3, join glue
Join the glue instrument and comprise Plastic Drum, plastic tub, plastic cup, graduated cylinder, stirring rod, agitator.Adopt the less plastic tub preparation resin glue I of volume, stir with stirring rod by hand; Adopt the larger Plastic Drum preparation resin glue II of volume, agitator stirs.Join after the glue, should take out 10 grams and do sample gelling experiment, observe its gelling time, prevent from solidifying too fast or excessively slow.
Resin glue after the promoter of measuring corresponding umber with graduated cylinder add to be stirred; After stirring, the curing agent of consumption statistic corresponding scores adds in the resin glue again; After stirring, add talcum powder, after this keep the stirring of resin glue.
Four, make gel coating resin 2
With the fiberglass brush special resin glue I for preparing is brushed equably on the surface of mould 1 former and formpiston, the glue consumption of resin glue I is 500g/m
2, namely gel coat thickness is at 0.4 ~ 0.5mm, and gel coat cold curing 1 hour reaches tactile dried rear stand-by.Five, make superficial layer 3
1, at first in the resin glue II for preparing, adds ultra-violet absorber.The ultra-violet absorber that herein adopts is the ultra-violet absorber UV-320 light stabilizer that Nanjing produces through sky latitude chemical industry Co., Ltd.It is rear stand-by to stir, and continues to keep the stirring of glue.
2, will be layered on the fiberglass surfacing mat that mould 1 surface size adapts on the gel coating resin 2, be evenly coated on the surperficial felt with the resin glue II of hair roller with modulation in the step 1, then use the deaeration of deaeration roller; Fill and lead up with dell or dead angle that resin glue will be difficult for making.Surface felt consumption is substance 30g/m
2, glue content is 85%.
Six, make enhancement layer 4
Described enhancement layer 4 comprises fiber reinforcing layer 9 and twin beams bracing means 10, and described fiber reinforcing layer 9 comprises glass chopped strand mats and para-aramid fiber cloth, and the concrete making step of described enhancement layer 4 is as follows:
1. make twin beams bracing means 10;
Described twin beams bracing means 10 profiles are " II " shape, the employing wet process forming method is made, described wet process forming method is to paste first interior adventitia, again interior adventitia is combined, then in die cavity, pour into the hard polyurethane foams foamed plastics, foamed solidification, finally demould namely become the foam layer product.Described twin beams bracing means wet process forming method flow process as shown in Figure 4, described method is specially: at first paste interior adventitia, with described interior adventitia combination; Select the selection of suitable foamed material; Be under 20 ~ 30 ℃ of conditions in temperature, perfusion hard polyurethane foams foamed plastics in the die cavity; Last foamed solidification and the demoulding form goods.
2. select suitable para-aramid fiber cloth, glass chopped strand mats, cut out by the specification requirement of product;
3. described para-aramid fiber cloth is boiled 20min in 80 ~ 90 ℃ water;
4. lay successively described para-aramid fiber cloth and glass chopped strand mats to setting thickness;
Described glass chopped strand mats and para-aramid fiber cloth in layer are routed on the described superficial layer 3, repeat successively until the thickness that needs.If when running into bent angle or shaggy block, then available scissors flattens the cloth clip with hairbrush.If when mould 1 two or more than two fiber cloth of larger palpus or felt overlap, should overlap 5cm.Simultaneously, the overlap joint between every layer should stagger as much as possible.The consumption mass ratio of para-aramid fiber cloth and resin glue II is 1:1.5.The consumption mass ratio of glass chopped strand mats and resin glue II is 1:2.9.
5. place described twin beams bracing means 10 at described para-aramid fiber cloth and glass chopped strand mats.
Seven, the laying of priming by vacuum device and sealing
Spreading first release cloth 5, then is flow-guiding cloth 6, is vacuum bag 7 at last, and described flow-guiding cloth also comprises mozzle or flow-guiding screen 6 times, plays drainage, and described enhancement layer 4 is infiltrated evenly.Before the vacuum bag 7 that closes, think over the trend of resin 13 and vacuum-pumping pipeline, otherwise some places resin 13 can can't infiltrate, adopt 11 pairs of described vacuum bags 7 of sealing strip to seal.Want extreme care during laying, in order to avoid some sharp objects puncture vacuum bag 7.Described priming by vacuum device is connected with other equipment by tube connector 8, and the bucket 12 that resin is used in perfusion is equipped with in end connection, and the other end connects vavuum pump.
Eight, the priming by vacuum of resin 13
The resin glue 13 that priming by vacuum is used is resin glue II, and resin glue 13 heats in container, stirs 3h under 680Pa vacuum, de-bubbled; To vacuumize in mould 1 die cavity, take out the bubble of 13 li of most resin glues and the moisture in the fiber parison, during dipping keep the vacuum of 40Pa in the die cavity; Injection initial vacuum treatment system drops to the vacuum that 130Pa(is not more than de-bubbled with the vacuum in the die cavity), and remain to always and fill with die cavity, with the pressure of 2.1MPa resin glue 13 is injected die cavities; Die cavity is full of the final vacuum degree and disappears, and the goods in the 101kPa lower impressions solidify.
Nine, the curing of product
Take steam as medium, heat energy is transmitted to 13 li of resin glues through mould 1 backing, shell, profile, and resin glue 13 is solidified.Because the thermal conductivity of mould therefor tool 1 is better, so firing rate is very fast.So the p-aramid fiber composite product requires 270 ~ 280 ℃ of lower curing of room temperature, cold curing 20 ~ 24h gets final product.
Ten, the demoulding
This method adopts qi exhaustion, be about to Special air nozzle and be contained in advance on the mould 1, valve links to each other with air pump by sebific duct, passes through valve during the demoulding, in the adhesive surface slit with the high pressure gas press-in die 1 of 390 ~ 680kPa and product, along with constantly entering of high pressure gas can eject product.Can hammer tapped pore place into shape with skin when suppressing, gas is entered rapidly.This release method is very effective to the large tracts of land shell product.
Must not firmly beat mould 1 with hard hammer during the demoulding, split because easy gel coating resin 2 with product and mould 1 shakes.
11, girth member and connector is fixing
Obtain respectively former and the formpiston of product by above-mentioned steps, between described former and formpiston, paste fixing described girth member and connector, the material of described girth member is the PVC foam, paste and frontly with resin putty girth member and connector are bonded at the inner face of the enhancement layer of described former and formpiston, coat again after cured; Metal connecting piece will be noted the location of connecting hole, if any screw, then should seal, and opens after the curing again, prevents that solation from advancing screw.
12, post processing
1, cuts edge: behind the product stripping,, add water during cutting and can make otch level and smooth along the line cutting with skive, reduce dust pollution.
2, processing: the p-aramid fiber composite product all need be processed, i.e. edging, deburring, cut-out, perforate etc.
(1) adopts sanding machine that the burr of hair side is destroyed, the blob of viscose of projection is tied, finishing side cut, chamfering etc.
(2) adopt toothless saw (also claiming the marble saw), add water and cut into required form.
13, check and accept
Comprise outward appearance, size 2 each side.
(1) appearance surfaces is that the products appearance of gel coat should reach: any surface finish, smooth, color and luster evenly, flawless, free from admixture, no wrinkle, without bubble etc.
(2) size, weight, appearance and size, gauge, distortion size, bore size, skeleton size, press the drawing tolerance and check and accept.Monomer weight, accessory weight, overall weight are checked and accepted on request.
Embodiment two
A kind of vacuum infusion molding method of p-aramid fiber composite product, Fig. 1 and Fig. 2 are the layer structure schematic diagram of p-aramid fiber composite product of the present invention in the priming by vacuum process, as shown in Figure 3, described method comprises the steps:
One, cleaning mould 1
Adopt the Combined mould 1 of stainless steel, comprise relative former and formpiston, prepared p-aramid fiber composite product is rectangular body shape product.Mould is stained with the cull that last time, the demoulding was left over, carefully roots out with flat chisel, can not damaging surface; Water cleans releasing agent, dries stand-by.
Two, brushing releasing agent
Add 5 parts of polyvinyl alcohol (low molecule powdery, mean molecule quantity is 16000~20000) after 45 parts of water are heated to 60 ~ 70 ℃, insulated and stirred cool to room temperature to the complete dissolving, 50 parts of ethanol of agitation and dropping again, filtration after finishing is except degranulation and impurity.Add at last 1 part of defoamer.
With the releasing agent of hairbrush in stainless steel mould 1 surface uniform brushing preparation, dry 30min after having brushed, stand-by behind the drying and forming-film.
Three, preparation resin glue
1, resin glue I: adopt 100 part of 196 unsaturated polyester resin, 2 parts of initator methyl ethyl ketone peroxides, 1 part of promoter naphthoic acid cobalt, 3.5 parts of anti-caking agent aerosils, 3 parts of defoamers, 10 parts of pigment paste preparations.Pigment paste adopts the loyal vast and boundless board environmental-friendly pigment paste that Jiangyin City loyal vast and boundless glass-reinforced plastic material Co., Ltd produces herein, and the trade mark is 558 black.
2, resin glue II: adopt 100 parts of shrinkage factors little (being generally 1%~3%), low viscosity, the pre-high-performance methacrylic acid epoxy vingl ester resin MERICAN30-200P that promotes, 10 parts of diluent acetone, 3 parts of initator methyl ethyl ketone peroxides, 6 parts be promoter styrene solution, 20 parts of talcum powder preparations as filler of 10% that the dimethylaniline of 1:1 and benzoyl peroxide are made into by mass ratio.
3, join glue: join the glue instrument and comprise Plastic Drum, plastic tub, plastic cup, graduated cylinder, stirring rod, agitator.Adopt the less plastic tub preparation resin glue I of volume, stir with stirring rod by hand; Adopt the larger Plastic Drum preparation resin glue II of volume, agitator stirs.Join after the glue, should take out 20 grams and do sample gelling experiment, observe its gelling time, prevent from solidifying too fast or excessively slow.
Resin glue after the promoter of measuring corresponding umber with graduated cylinder add to be stirred; After stirring, the curing agent of consumption statistic corresponding scores adds in the resin glue again; After stirring, add talcum powder, after this keep the stirring of resin glue.
Four, make gel coating resin 2
With the fiberglass brush special resin glue I for preparing is brushed equably on the surface of mold cavity block and formpiston, the glue consumption of resin glue I is 500g/m
2, namely gel coat thickness is at 0.4 ~ 0.5mm, and gel coat cold curing 1 hour reaches tactile dried rear stand-by.
Five, make superficial layer 3
1, at first in the resin glue II for preparing, adds ultra-violet absorber.The ultra-violet absorber that herein adopts is the ultra-violet absorber UV-320 light stabilizer that Nanjing produces through sky latitude chemical industry Co., Ltd.It is rear stand-by to stir, and continues to keep the stirring of glue.
2, will be layered on the fiberglass surfacing mat that mould 1 surface size adapts on the gel coating resin 2, be evenly coated on the surperficial felt with the resin glue II of hair roller with modulation in the step 1, then use the deaeration of deaeration roller; Fill and lead up with dell or dead angle that resin glue will be difficult for making.Surface felt consumption is substance 50g/m
2, glue content is 95%.
Six, make enhancement layer 4
Described enhancement layer 4 comprises fiber reinforcing layer 9 and twin beams bracing means 10, and described fiber reinforcing layer 9 comprises glass chopped strand mats and para-aramid fiber cloth, and the concrete making step of described enhancement layer 4 is as follows:
1. make twin beams bracing means 10;
Described twin beams bracing means 10 profiles are " II " shape, the employing wet process forming method is made, described wet process forming method is to paste first interior adventitia, again interior adventitia is combined, then in die cavity, pour into the hard polyurethane foams foamed plastics, foamed solidification, finally demould namely become the foam layer product.Described twin beams bracing means wet process forming method flow process as shown in Figure 4, described method is specially: at first paste interior adventitia, with described interior adventitia combination; Select the selection of suitable foamed material; Be under 20 ~ 30 ℃ of conditions in temperature, perfusion hard polyurethane foams foamed plastics in the die cavity; Last foamed solidification and the demoulding form goods.
2. select suitable para-aramid fiber cloth, glass chopped strand mats, cut out by the specification requirement of product;
3. described para-aramid fiber cloth is boiled 20min in 80 ~ 90 ℃ water;
4. lay successively described para-aramid fiber cloth and glass chopped strand mats to setting thickness;
Described glass chopped strand mats and para-aramid fiber cloth in layer are routed on the described superficial layer 3, repeat successively until the thickness that needs.If when running into bent angle or shaggy block, then available scissors flattens the cloth clip with hairbrush.If when mould 1 two or more than two fiber cloth of larger palpus or felt overlap, should overlap 5cm.Simultaneously, the overlap joint between every layer should stagger as much as possible.The consumption mass ratio of para-aramid fiber cloth and resin glue II is 1:1, and the consumption mass ratio of glass chopped strand mats and resin glue II is 1:1.9.
5. place described twin beams bracing means 10 at described para-aramid fiber cloth and glass chopped strand mats.
Seven, the laying of priming by vacuum device and sealing
Step 7 with embodiment one.
Eight, the priming by vacuum of resin 13
The resin glue 13 that priming by vacuum is used is resin glue II, and resin glue 13 heats in container, stirs 3h under 700Pa vacuum, de-bubbled; To vacuumize in mould 1 die cavity, take out the bubble of 13 li of most resin glues and the moisture in the fiber parison, during dipping keep the vacuum of 42Pa in the die cavity; Injection initial vacuum treatment system drops to the vacuum that 140Pa(is not more than de-bubbled with the vacuum in the die cavity), and remain to always and fill with die cavity, with the pressure of 2.1MPa resin 13 is injected die cavities; Die cavity is full of the final vacuum degree and disappears, and the goods in the 101kPa lower impressions solidify.
Nine, the curing of product
Step 9 with embodiment one.
Ten, the demoulding
Step 10 with embodiment one.
11, girth member and connector is fixing
Described girth member material is metal, and other steps are with the step 11 of embodiment one.
12, post processing
Step 12 with embodiment one.
13, check and accept
Step 13 with embodiment one.
Above-described embodiment is described preferred embodiment of the present invention; be not that scope of the present invention is limited; design under the prerequisite of spirit not breaking away from the present invention; various distortion and improvement that those of ordinary skills make technical scheme of the present invention all should fall in the definite protection domain of claims of the present invention.