WO2019197562A1 - Appareil amélioré pour moulage par réaction et injection - Google Patents

Appareil amélioré pour moulage par réaction et injection Download PDF

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Publication number
WO2019197562A1
WO2019197562A1 PCT/EP2019/059318 EP2019059318W WO2019197562A1 WO 2019197562 A1 WO2019197562 A1 WO 2019197562A1 EP 2019059318 W EP2019059318 W EP 2019059318W WO 2019197562 A1 WO2019197562 A1 WO 2019197562A1
Authority
WO
WIPO (PCT)
Prior art keywords
feeding
mixing
shutter device
mold
dosing head
Prior art date
Application number
PCT/EP2019/059318
Other languages
English (en)
Inventor
Marco VOLPATO
Andrea CASTELNOVO
Original Assignee
Cannon Tipos S.R.L.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cannon Tipos S.R.L. filed Critical Cannon Tipos S.R.L.
Publication of WO2019197562A1 publication Critical patent/WO2019197562A1/fr

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B7/00—Mixing; Kneading
    • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
    • B29B7/76—Mixers with stream-impingement mixing head
    • B29B7/7631—Parts; Accessories
    • B29B7/7636—Construction of the feed orifices, bores, ports
    • B29B7/7642—Adjustable feed orifices, e.g. for controlling the rate of feeding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B7/00—Mixing; Kneading
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B7/00—Mixing; Kneading
    • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
    • B29B7/7471—Mixers in which the mixing takes place at the inlet of a mould, e.g. mixing chambers situated in the mould opening
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B7/00—Mixing; Kneading
    • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
    • B29B7/76—Mixers with stream-impingement mixing head
    • B29B7/7631—Parts; Accessories
    • B29B7/7647—Construction of the mixing conduit module or chamber part
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B7/00—Mixing; Kneading
    • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
    • B29B7/76—Mixers with stream-impingement mixing head
    • B29B7/7663—Mixers with stream-impingement mixing head the mixing head having an outlet tube with a reciprocating plunger, e.g. with the jets impinging in the tube
    • B29B7/7684—Parts; Accessories
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29B—PREPARATION OR PRETREATMENT OF THE MATERIAL TO BE SHAPED; MAKING GRANULES OR PREFORMS; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIAL CONTAINING PLASTICS
    • B29B7/00—Mixing; Kneading
    • B29B7/74—Mixing; Kneading using other mixers or combinations of mixers, e.g. of dissimilar mixers ; Plant
    • B29B7/76—Mixers with stream-impingement mixing head
    • B29B7/7663—Mixers with stream-impingement mixing head the mixing head having an outlet tube with a reciprocating plunger, e.g. with the jets impinging in the tube
    • B29B7/7684—Parts; Accessories
    • B29B7/7689—Plunger constructions
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/27—Sprue channels ; Runner channels or runner nozzles
    • B29C45/28—Closure devices therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C45/00—Injection moulding, i.e. forcing the required volume of moulding material through a nozzle into a closed mould; Apparatus therefor
    • B29C45/17—Component parts, details or accessories; Auxiliary operations
    • B29C45/26—Moulds
    • B29C45/27—Sprue channels ; Runner channels or runner nozzles
    • B29C45/30—Flow control means disposed within the sprue channel, e.g. "torpedo" construction
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C67/00—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00
    • B29C67/24—Shaping techniques not covered by groups B29C39/00 - B29C65/00, B29C70/00 or B29C73/00 characterised by the choice of material
    • B29C67/246—Moulding high reactive monomers or prepolymers, e.g. by reaction injection moulding [RIM], liquid injection moulding [LIM]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
    • B29K2101/00—Use of unspecified macromolecular compounds as moulding material
    • B29K2101/10—Thermosetting resins

Definitions

  • the present invention refers to an improved apparatus for reaction and injection molding comprising at least one mixing and dosing head of expanding thermosetting resins and a mold, said mold having:
  • the invention refers, in particular, to an apparatus that allows to eliminate idle time due to waiting for the end of the reaction times of the material in a system that adopts an injection technology with mixing and dosing.
  • the invention also refers to industrial processes of the HPRTM (High Pressure Resin Transfer Moulding) type in which production times are optimized.
  • HPRTM High Pressure Resin Transfer Moulding
  • reagent resins are dosed in a stoichiometric ratio in connection with a mixing device, commonly referred to as mixing and dosing head.
  • a mixing device commonly referred to as mixing and dosing head.
  • resins are intimately mixed as a result of mechanical agitation obtained by means of rotating mixers or as a result of high turbulence generated by jets of the resins that crash in an area of limited dimensions commonly referred to as mixing chamber.
  • mixing the mixed resins are still in a liquid state and, while the chemical reaction thereof starts, they are released or injected as a result of the pressure existing in the mixing chamber, in the molding cavity where they are intended to be.
  • the mixing head releases a certain quantity of material that, once expanded, saturates the inner volume of the mold, expanding, for example, thirty times with respect to the volume of the liquid, and making manufactured products with said characteristics.
  • the mixing and dosing head is moved towards a different mold, repeating the same process, and so on, thus obtaining a production in parallel.
  • Such process which guarantees an advantage due to the use of more than one mold simultaneously, adopting a unique mixing and dosing head, can be actuated only with molds that are open during the casting phase or closed but whose injection holes are positioned on the head of the fluid introduced and, in any case, only when the introduction of the reagent resin occurs at atmospheric pressure and the expansion and solidification reaction of the material is relatively slow.
  • the mixing head can be removed without particular problems and can be substituted by a non-hermetic closing device of the injection hole and without mechanical peculiarities.
  • a silicone cap activated by an air piston is enough.
  • the vacuum must be practiced in the mold before injection, or if the injection is made with a pre-determined pressure and particularly with a high gradient of pressure to make the resins slide within stratified fibers, or still if the cavity, even if filled, must be kept under pressure until the solidification of the resins, it is not conceivable to operate the removal of the mixing head unless the cavity is kept in said conditions to obtain components that require high quality.
  • HPRTM processes are also known that are different from the processes with expanding resins and that are used on the basis of the characteristics of the piece to obtain.
  • HPRTM processes have recently been developed in the automotive sector, mainly to make components of the structural and aesthetic highest quality in a composite material, for example carbon fiber, basically to lighten the weight of the supporting structure of automobiles or of the component parts thereof considering the pressing need to reduce fossil fuels consumption and the necessity to build electric propulsion cars.
  • This technology allows to produce in a relatively short time thousands of pieces with the same dimensions and characteristics and by means of a repeatable and quick industrial process.
  • a HPRTM process provides for the operation with virgin or recycled, not pre-impregnated, fiber layers, with an affordable basic and provision cost and with impregnation and polymerization times of the order of some hundreds of seconds.
  • the HPRTM process also provides for the mixing of the reactive resins by means of a high pressure mixing head where the mixing of the resins is obtained thanks to the high turbulence generated by the impingement of jets produced by high pressure and to the injection of the reagent compound in the cavity of the mold in an almost barycenter position or anyway in a proper position for being able to impregnate all the fiber contained therein.
  • the injection operation lasts from a few seconds to some tenths of seconds and the reagent resin spreads from the injection point through all the fiber until it arrives to the most peripheral spread end areas.
  • the pressure within the cavity of the mold increases in correspondence of the injection point and in the first spread area on account of the resistance to sliding that the resin encounters while it spreads through the fibers.
  • the reagent resin has filled the whole cavity, an abrupt increase in pressure in the cavity occurs and this peak of pressure is limited by the closure of the mixing head.
  • a pressure sensor installed facing the cavity of the mold in proximity of the resin inlet area, detects the pressure of the reagent resin in the cavity of the mold and provides the signal for the closure of the mixing head in such a way as to stop the filling and to limit the peak of pressure to the desired values for compacting.
  • the mold is kept at a temperature suitable for accelerating the reaction of the resin (for example, higher than 100°C) and, once the injection phase has been completed, the reagent resin injected quickly starts to polymerize until solidification and to form the mechanical characteristics of the piece to obtain.
  • a temperature suitable for accelerating the reaction of the resin for example, higher than 100°C
  • the polymerization is also stimulated by the heat produced by the reaction of the resin itself, so that the polymerization necessary to the removal of the piece from the mold, the so-called de-molding, is obtained.
  • the HPRTM process Even if advantageous under various aspects, and always more intended to be spread in the industrial field, the HPRTM process still has operative inconveniences; in particular it still requires a temporal optimization of the production process.
  • the traditional HPRTM process described above provides that, once the mixing and injection phase has been completed the supply of the reagent resin and has hermetically closed its own resin introduction duct, the head remains in position, locking the access hole to the cavity of the mold until the completion of the thermosetting of the material, since a detachment or the anticipated removal would imply serious damages due to the high pressures still at stake. In fact, it is not conceivable to separate the head, thus causing the release of the pressure without causing the immediate damage of the component to make. This situation basically takes place with all thermosetting resins, and in particular with the following resins: polyure thane, epoxy, vinyl ester, polyamide, unsaturated polyester, phenolic resins, and with silicones.
  • the dosing process of expanded materials in a cavity provides that the final density of the manufacture is determined by the dosed quantity of reagent materials in said cavity during the first phase of the process and by the pressure generated by the expansion itself of the material injected.
  • the forming area In order to generate the correct pressure inside the forming area, the forming area itself must be hermetic.
  • the technical problem that is at the basis of the present invention is that of devising an apparatus and a relative industrial process for allowing a correct dosing of material in one mold having more than one cavity, even different ones, and a safe detachment of a mixing and dosing head from a reaction and injection molding system employable both for compact thermosetting reagent resins and for expanding thermosetting resins, said apparatus and said process having respective structural and functional characteristics such as to overcome the inconveniences that still limit the processes of the prior art.
  • Another aim of the present invention is to devise an apparatus and a relative industrial process that allows to increase the efficiency of the whole reaction and injection molding industrial process.
  • Another aim of the present invention is to devise a process that can be applied and actuated in industry with relatively low costs, though guaranteeing a very high efficiency in terms of quality for obtaining components obtained by molding in large series.
  • the idea of solution that is at the basis of the present invention is that of providing an apparatus capable of allowing isolating of every cavity present in a mold from the other ones connected to the same adduction portion of both compact and expanding thermosetting resins, allowing then decoupling the mixing and dosing head from the mold at the end of the injection phase, so that the mixing and dosing head can eventually be repositioned and used on at least one different mold in the course of the completion of the polymerization and formation of the components of the first mold.
  • the invention must allow to use molds in which there is more than one forming area even of different dimensions, adapted to obtain pieces of even different densities, having a unique introduction point of the material and therefore using a unique mixing and dosing head. Further, the apparatus according to the invention must provide for the possibility of feeding multiple casting areas in the same mold through a unique adduction portion of the compact or expanding thermosetting resins.
  • an improved apparatus for reaction and injection molding comprising at least one mixing and dosing head of a mixture of expanding thermosetting resins and a mold, said mold having:
  • a shutter device that is active on at least a fluid path defined between the adduction portion and said at least one feeding and distribution channel, upstream of said at least one casting and forming area to allow decoupling said mixing and dosing head by intercepting said at least one fluid path at the end of the introduction phase of said mixture of expanding thermosetting resins.
  • the shutter device is a hollow cylinder coaxial to the coupling bush of the adduction portion and in which a depressor piston is housed that is mobile along the cavities of the cylinder interlocked to a negative pressure actuator.
  • Said shutter device provided on the fluid path is interlocked to a flow rate measurement system that thus allows precisely adjusting the distribution of dosed quantities of mixture of thermosetting reagent resins in the casting and forming area, meanwhile allowing decoupling said mixing and dosing head at the end of the introduction phase of said mixture of expanding thermosetting resins.
  • the adduction portion is the only introduction inlet for a plurality of feeding and distribution channels flowing into corresponding casting areas.
  • Such adduction portion comprises a coupling bush for connecting said operating end of the mixing and dosing head by means of a through-hole and flows in at least one feeding and distribution channel on which said shutter device is active transversally.
  • a closing and abutment bush is provided in a position facing the shutter device with respect to the feeding and distribution channel and has a recess that is structured for shape coupling with a beveled end of the shutter device.
  • the shutter device is made of a harder material than the material which said closing and abutment bush is made of.
  • the shutter device can be preferably positioned in a condition coaxial to the axis of the adduction portion and can also be extended in an offset position with respect to the axis of the adduction portion in order to lock one or more unique feeding and distribution channels.
  • the shutter device When in an offset position the shutter device comprises a cylindrical rod that is movably guided transversally to said at least one feeding and distribution channel interlocked to a flow rate measurement system to detect at least a completion and the end of the injection phase.
  • the invention also refers to a reaction and injection molding process wherein the use of at least one dosing and mixing head of reagent and expanding thermosetting resin and a mold are provided, said mold comprising:
  • thermosetting reagent resin a thermosetting reagent resin into the mold until the injection phase has been completed
  • a depressurization and suction phase of residues of the mixture of thermosetting resins by means of the same shutter device comprising a hollow cylinder having an end that is movably guided transversally to the fluid path and inside which a depressor piston is movable.
  • thermosetting resin occurs sequentially in multiple casting areas inside the mold itself and in fluid communication by means of respective feeding and distribution channels with a unique adduction portion of unique injection point.
  • the sequentiality and selection of the feeding and distribution channel to be fed occurs by activating respective shutter devices provided in a number equal to the channels present and arranged on the respective channel.
  • the activation of the depressor to increase the volume can be activated both following the actual sealing of the adduction chamber detectable by means of a pressure switch installed on the control device or with a slight anticipation on the detected sealing position by means of a micro-switch or a proximity sensor installed on the cylinder that controls the movement of the shutter.
  • the depressor is controlled in an extended or retracted position in the hollow cylinder by means of a hydraulic piston that moves a carriage provided with inclined grooves along which it engages by means of proper sliding pins or slides applied at the end thereof along the sides.
  • coupling bush, inserting bush, shutter device and depressor piston are assembled in the respective seats using sliding gaskets and seals composed of materials adapted to resist to high temperatures, for example Teflon or FKM-Viton gaskets that resist up to 200°C.
  • Figure 1 shows a schematic diagram in plan view of a portion of a mold having the molding imprint and made according to the present invention
  • figure 2 shows a perspective and schematic view of the mold comprising the imprint of figure 1
  • figure 3 shows a perspective view of a detail of an apparatus according to an embodiment of the present invention
  • figure 4 shows a section view of the details of figure 3 taken according to an orthogonal direction
  • - figure 4A shows an enlarged scale view of the details of figure 4
  • figure 5 shows the apparatus of figure 3 in the introduction phase of the mixture of thermosetting reagent resins
  • figure 6 shows the apparatus of figure 3 in the condition in which a shutter is in sealing phase of the adduction duct
  • - figure 7 shows the apparatus of figure 3 in the activation phase of a depressor piston
  • figure 8 shows the apparatus of figure 3 in the detachment phase of the mixing and dosing head
  • figure 9 shows a schematic view in section of an alternative embodiment according to the present invention
  • - figure 10 shows a further embodiment according
  • reaction and injection molding apparatus made according to the present invention for decoupling a mixing and dosing head 9 of reagent resins from a mold 2 in which the mixture of reagent resins is kept under pressure.
  • This decoupling occurs according to the invention immediately after the completion of the introduction of the mixture of fluid reagent resins, that is, in order to optimize the production process times.
  • the invention is particularly suitable when it is useful to adopt multiple molds for a manufacture in parallel, having a unique injection system available with mixing and dosing head 9.
  • the description that follows is made with particular reference to this embodiment with the aim of simplifying the presentation thereof.
  • the apparatus 1 is associated with a mold 2 structured with a pair of semi-shells that are closable with valves.
  • the mold 2 has at least one adduction and insertion portion 3 of the resin, at least one feeding and distribution channel or chamber 4 and at least one forming tank or area 5.
  • the mixture of fluid reagent resins is made to advance to the adduction portion 3 by the mixing and dosing head 9 and flows through the feeding and distribution channel 4 up to the inside of the casting and forming area 5.
  • feeding and distribution channels 4 there can also be two or more feeding and distribution channels 4, in which case on them are provided housing holes 16, which can be seen in figure 1 , of valve means 6 of casting selection, which can be seen in figures 9, 10 and 1 1 and as will become apparent from the description that follows.
  • the adduction portion 3 of the apparatus 1 comprises a coupling bush 7 for the mixing and dosing head and a feeding bush 8.
  • the feeding bush 8 is connected to the coupling bush 7 in correspondence of an inner end thereof 10 substantially seamlessly and in coaxial extension.
  • the coupling bush 7 is adapted to receive the operative end of the mixing and dosing head 9.
  • the coupling bush 7, in the present illustrative and non-limiting embodiment, has a T-shaped longitudinal section with a central through-hole 10 of constant diameter.
  • the feeding bush 8 is placed between the coupling bush 7 and the feeding and distribution channel 4.
  • the coupling bush 7 and the feeding bush 8 coincide in the same monolithic structure.
  • the two bushes 7 and 8 have been hypothesized as structurally independent even if coupled between them seamlessly to form a unique introduction duct that flows into the feeding and distribution channel 4.
  • the feeding bush 8 in the non-limiting example described here, has a trunk-conical-shaped inner channel with a first trunk-conical portion 1 1 having base section in communication with the top section of a second trunk-conical portion 12 still more flared with respect to the previous one. This second portion 12 flows into the feeding and distribution channel 4.
  • the feeding bush 8 provides that the first trunk-conical portion 1 1 has a smaller diameter 13 that is in correspondence and coincides with the diameter of the through-hole 10 of the coupling bush 7, and a larger or base diameter 14 that is in correspondence of the second trunk-conical portion 12. None would impede, however, that the inner channel of the feeding bush 8 is conformed according to a unique trunk-conical shape that puts the hole 10 in communication with the feeding and distribution channel 4.
  • the apparatus 1 comprises, further, a hollow cylinder shutter device 15 preferably arranged coaxially to the coupling bush 7 and transversally to the feeding and distribution channel 4.
  • the shutter device 15 is advantageously situated in proximity of the adduction portion 3, that is, of the coupling bush 7 and of the relative feeding bush 8 in such a way as to be able to interfere with the fluid path of the section of feeding duct formed by the holes 10, 1 1 and 12 facing the feeding and distribution channel 4.
  • the shutter device 15 is housed inside the mold 2, in particular in one of the two semi-molds, in a substantially facing position with respect to the flared second portion 12 of the feeding bush 8, coaxially with it.
  • the shutter device 15 is conformed as a cylinder that is internally hollow along a longitudinal dimension thereof for internally housing a depressor piston 21.
  • the shutter device 15 has a distal end 17 addressed towards the feeding and distribution channel 4, which has a peripheral bevel 26, which can be clearly seen in the sections of figures 4, 4A and 5.
  • This shutter device 15 is movably guided by motorized means 30 from and towards the adduction portion 3, and, in particular, from and towards the feeding bush 8, in such a way as to lock and seal the fluid path of the section of feeding duct formed by the holes 10, 1 1 and 12 facing the feeding and distribution channel 4 downstream of the feeding bush 8.
  • the flared second portion 12 of the bush 8 in correspondence of its own larger diameter 14, has a corresponding inner- wall inclination in same shape coupling with the peripheral bevel 26 of the shutter device 15.
  • the shutter device 15 is activated approaching and moving away with respect to the feeding bush 8 by an actuator device 24 that, in this case, always in a non-limiting manner, is arranged with a cavity 32 that allows the insertion of a carriage mechanism 34 that controls the movement of the depressor 21 independently.
  • the shutter device 15 and the feeding bush 8 are preferably made of a different material, in particular the material of the shutter device 15 being harder than the material of the feeding bush 8.
  • the feeding bush 8 can coincide with the adduction bush 7 according to the need to arrange the apparatus 1.
  • the shutter device 15 in the hollow cylinder shape, houses in the inner cavity 20 thereof a depressor piston 21 movable along the shutter device 15.
  • the depressor piston 21 in correspondence of a proximal end 22 opposite to the feeding and distribution channel 4 slides along a specific carriage 34 with inclined slide 23 to obtain the longitudinal movement along the inner cavity 20.
  • coupling bush 7, feeding bush 8, shutter device 15 and depressor piston 21 are assembled in the respective seats using seals 29 adapted to resist to high temperatures, for example Teflon or FKM-Viton seals or gaskets that resist even up to 200°C.
  • the shutter device 15 with depressor piston 21 in a particular version thereof with fixed depressor piston 21 , can be advantageously used, other than for HPRTM processes, also for reaction molding processes with expanding resins.
  • the shutter device 15 can be installed no more coaxially to the adduction portion 3, but in correspondence of the feeding and distribution channel 4.
  • the shutter device with relative depressor piston can be provided for separating the adduction area from the feeding area and therefore from the rest of the mold, since the pressure inside the cavity of the mold will be generated by the expanding material itself, subsequently to the end of the injection, that is, to the removal of the mixing and dosing head.
  • the devise of the present invention can be exploited with expanding resins to leave space to the expansion of the residue material in the adduction portion, with the shutter device installed in a coaxial position with respect to the mixing and dosing head.
  • These shutter devices 15 constitute, basically, the valve means 6 described previously with reference to the relative housing holes 16 provided in the mold 2 for the casting selection.
  • each shutter device 15 a corresponding closing and abutment bush 25 is arranged in a position facing the shutter device with respect to the feeding and distribution channel 4.
  • the closing and abutment bushes 25 have a recess 27 in correspondence of the feeding and distribution channel that is likely to shape couple with the peripheral bevel 26 of the shutter device 15 as with the previous embodiment.
  • the shutter devices can be conformed as a full cylinder, as represented, for example, in figure 1 1.
  • the operative end of the mixing and dosing head 9 is inserted in the adduction portion 3.
  • the mixing and dosing head 9 has an operative end containing the supply chamber in which a conventional closure and expulsion valve element of the mixture of reagent resins slides and that is inserted in the hole 10 of the coupling bush 7.
  • the mixture of fluid reagent resins is introduced through the adduction fluid path and the canalization represented by the coaxial holes 10, 1 1 and 12 of the bushes 7 and 8 and flows through the flared second portion 12 of the feeding bush 8 inside the feeding and distribution channel 4, through which it flows inside the forming area 5.
  • the end of the injection phase is determined according to modalities known in the dosing technique of the reagent resins.
  • the shutter device 19 activated by the motorized means 30 shape couples the shutter device 15 with the feeding bush 8, in particular, the peripheral bevel 26 with the inner wall 18 of the flared second portion 12.
  • the fluid communication between the flared second portion 12 and the feeding and distribution channel 4 is therefore interrupted and sealed.
  • the actuator 24 makes the carriage 34 with inclined slide 23 slide, inducing the movement of the depressor piston 21 away from said feeding and distribution channel 4.
  • the pressure inside the volume comprised between depressor piston 21 and the flared second portion 12 diminishes abruptly and it is possible to separate and extract the mixing and dosing head 9 from the mold 2 without problems, no residues of mixture of fluid reagent resin or in course of thermosetting remaining along the fluid path.
  • the possibility is thus obtained of disengaging and removing the head without staining the mold and of adequately cleaning the hole of the coupling bush 7 and of the feeding duct.
  • thermosetting reagent resins are introduced, and if mixtures of expanded thermosetting reagent resins are introduced.
  • the difference between the two cases is in the greater space freed by residues of resin that is required to be formed by the movement of the depressor piston 21 away from the feeding channel 4, to consider a different volume of expansion of the mixtures of expanding or non-expanding compact thermosetting reagent resins.
  • thermosetting reagent resins In the case of the mixtures of compact thermosetting reagent resins it is possible to determine the end of the introduction of material adopting without distinction the techniques described above, in the case of the expanded thermosetting resins such end is identified only by means of reaching the desired casting weight.
  • the process described is bound to a preventive selection phase.
  • the locking by means of the activation of the respective shutter of a branch of feeding and distribution channel 4, or of a series of feeding and distribution channels 4 can occur in a plurality of modalities, of the sequential or contemporaneous type, on the basis of the specific characteristics of the material that has to flow and of the specific filling process of the cavity of the mold required, variable on a case by case basis.
  • the shutter device for production easiness reasons, in some cases, as can be seen in figure 1 1 , can be conformed as a full cylinder.
  • the present invention solves the technical problem and has several advantages, the first one is surely that it is possible to produce manufacturing in parallel on more than one mold 2 under pressure adopting a unique mixing and dosing head 9, without waiting the various polymerization times. This allows to increase significantly the efficiency of the whole reaction molding process.
  • the invention allows to optimize the necessary number of molds and, consequently, the number of placements of the mixing and dosing head, allowing to make more than one part, the same or different, with a unique molding equipment, eliminating inactivity time relative to the passage of the mixing and dosing head from a mold to another one.
  • the invention avoids the staining or locking of the adduction portion 3 of the mold even if it is used in a continuous manner, without periodic human intervention.
  • a further advantage is also represented by the fact that the safety of the operation is guaranteed, a clue point given the high pressures at stake and the temperature of the reagent resins.
  • Another advantage is that of allowing a functioning that is adaptable to the cases in which one or a plurality of forming tanks 5 internal to the same mold 2 is provided.
  • thermosetting reagent resins for compact thermosetting resins.
  • thermosetting resins for expanded thermosetting resins.
  • a further advantage is given by the optimization in economic terms of the production connected with the optimization of production times.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Injection Moulding Of Plastics Or The Like (AREA)
  • Processing And Handling Of Plastics And Other Materials For Molding In General (AREA)
  • Polymerisation Methods In General (AREA)

Abstract

L'invention concerne un appareil et un procédé relatif de moulage par réaction et injection, l'appareil comprenant au moins une tête de mélange et de dosage (9) pour un mélange de résines thermodurcissables expansibles et un moule, comprenant : - au moins une partie d'adduction (3) à accoupler avec une extrémité de fonctionnement de la tête de mélange et de dosage (9), - au moins un canal d'alimentation et de distribution (4) et au moins une zone de formation (5) en communication fluidique l'un avec l'autre et avec la partie d'adduction. Avantageusement, l'appareil comprend en outre au moins un dispositif d'obturation (15) qui est actif sur au moins un trajet de fluide défini entre la partie d'adduction (3) et le ou lesdits canaux d'alimentation et de distribution (4), qui est en amont de la ou desdites zones (5) pour permettre le découplage de la tête de mélange et de dosage (9) en interceptant le ou lesdits un trajets de fluide à la fin de la phase d'introduction dudit mélange de résines thermodurcissables expansibles, le dispositif d'obturation (15) comprenant un cylindre creux qui est coaxial à l'embout de raccordement (7) de la partie d'adduction (3) et dans lequel est logé un piston de dépression (21), qui est mobile le long des cavités (20) du cylindre verrouillé à un actionneur de dépression (19). En outre, une phase de dépressurisation et de lavage à contre-courant des résidus du mélange de résines thermodurcissables est fournie, au moyen du même dispositif d'obturation (15) ; à ce moment, il est possible d'enlever la tête de mélange et de dosage en toute sécurité.
PCT/EP2019/059318 2018-04-13 2019-04-11 Appareil amélioré pour moulage par réaction et injection WO2019197562A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT102018000004506A IT201800004506A1 (it) 2018-04-13 2018-04-13 Apparecchiatura perfezionata per stampaggio a reazione ed iniezione
IT102018000004506 2018-04-13

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WO2019197562A1 true WO2019197562A1 (fr) 2019-10-17

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4307760A (en) * 1977-11-02 1981-12-29 Wilhelm Hedrich Vakuumanlagen Gmbh & Co. Kg Pressure-regulated mold-filling apparatus for thermosetting material
DE19811466A1 (de) * 1998-03-17 1999-09-23 Zahoransky Formenbau Gmbh Spritzgießwerkzeug
EP1052078A1 (fr) * 1999-05-08 2000-11-15 HEKUMA Herbst Maschinenbau GmbH Contrôle de processus individuel dans un moule
WO2001021377A1 (fr) * 1999-09-21 2001-03-29 Synventive Molding Solutions, Inc. Systeme de rampe de distribution a regulation de debit

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4307760A (en) * 1977-11-02 1981-12-29 Wilhelm Hedrich Vakuumanlagen Gmbh & Co. Kg Pressure-regulated mold-filling apparatus for thermosetting material
DE19811466A1 (de) * 1998-03-17 1999-09-23 Zahoransky Formenbau Gmbh Spritzgießwerkzeug
EP1052078A1 (fr) * 1999-05-08 2000-11-15 HEKUMA Herbst Maschinenbau GmbH Contrôle de processus individuel dans un moule
WO2001021377A1 (fr) * 1999-09-21 2001-03-29 Synventive Molding Solutions, Inc. Systeme de rampe de distribution a regulation de debit

Also Published As

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