DE102018133115A1 - injection system - Google Patents

Abstract

Injection system for mixing components of a thermoplastic resin system with at least one filler (11) and introducing a resulting mixture (33) into a mold cavity (35) of a molding tool (2)
a mixing container (34) which can be fluidly connected to the mold cavity (2),
a first introduction device (31) for introducing the at least one filler (11) into the mixing container (34),
- One of the first introduction device (31) separate second introduction device (32) for the common or separate introduction of the components of the thermoplastic resin system in the mixing container (34) and
- A piston (9) for jointly bringing the mixture in the mixing container (34) (33) from the mixing container (34) into the mold cavity (35).

Description

The present invention relates to an injection system and a method for mixing components of a thermoplastic resin system with at least one filler and for introducing a resulting mixture in a mold cavity of a mold and a use of a corresponding injection system.

The production of polyamide 6 from caprolactam by anionic polymerization is well known to those skilled in the art ( US3017391A ) and is widely used, especially in casting processes for the production of small batches. The use of reinforcing fibers to improve the mechanical properties of plastic components is also well known. Various methods have already been described for producing fiber-reinforced composite components.

First, the processing of short fibers reinforced thermoplastic molding compositions by injection molding. Here, short cycle times and thus an economically attractive process management are achievable. However, the range of realizable components is limited in particular to rather thin-walled components.

Continuous incorporation and impregnation of fibers using single screw extruders is also disclosed in U.S. Patent Nos. 5,416,866, 5,869,842, 5,805,842, 3,805,842, and 3,805,842 DE102009056653 described the use of co-rotating twin screw extruders for introducing fibers into a melt in the EP0995567B1 ,

In the field of reactive processing, the fiber spraying process has become established for the processing of cut or long glass fibers. Here, the fibers are sprayed together with the reactive matrix (usually polyurethane spray systems) in an open shaping tool. The mixing of fibers and matrix can already take place in the mixing head, for example, discloses DE102009011900B3 for this purpose a mixing head with a separate Faserzuführkanal. Alternatively, also in the DE2628854A1 Propagated mixing by the combination of different sprays of reactive matrix and the fibers outside of the mixing head possible. In both cases, the spray application is automated and along a given trajectory, then the mold is closed and the matrix hardens under elevated temperature.

Occasionally, there are already application examples for fiber spraying processes with carbon fibers, in particular if it is possible to fall back on waste residues or recycled material. In order for a spraying process to be used under normal ambient conditions, the resin system must be substantially insensitive to atmospheric moisture and it must still be liquid at room temperature.

For the addition of cut fibers with several millimeters of length to thermoplastic reactive systems, however, there are only isolated solutions. For example, in the field of prototype fabrication by vacuum casting, two caprolactam components with activator and catalyst are premixed using a static mixer. With the help of a stirrer then short glass fibers are introduced and by pivoting the mixing container, the fiber-containing mass can be poured under vacuum into a mold cavity. ( Ehleben, M., Cubic AS, Mertens T., Fischer F., Vogel H .: Testable prototypes reasonably priced and fast. Plastics 05 (2017), p. 48-51 )

In this context, instead of pivoting a mixing vessel, it has also been described the incorporation of filler particles, such as reinforcing fibers, using an agitator and discharge by means of piston systems ( Wagner, P .: Processing of Caprolactam to Polyamide Moldings by the RIM Process. Plastics 73 (1983), p. 588-590 ).

Excellent mechanical properties can be achieved through the use of continuous filaments such as woven fabrics. The textiles are introduced into the process in the form of preformed semi-finished products of glass or carbon fibers, so-called preforms.

In wet pressing, the preforms are wetted in an open mold with the reactive system used and then closed. At elevated temperatures, curing of the reactive matrix occurs. For reasons of process economy, the application of resin can also take place outside the mold, while at the same time in the mold cures another component. This procedure is eg in the EP 3 037 247 A1 described.

By contrast, in the high-pressure resin injection process, which is already undergoing widespread industrial application, preforms are impregnated in a closed molding tool with the reactive system and then cured under pressure and temperature. A more detailed description of the process gives the EP2492074A1 , As matrices two-component reactive systems such as the precursors of epoxy resins or polyurethanes can be used. For the production thermoplastic continuous fiber reinforced components are the reactive systems mentioned above based on ε-caprolactam used, the process is referred to as in situ, RIM-PA or T-RTM method.

For the injection of reactive matrix components of thermoplastic reactive systems, the in the AT515952B1 proven Kolbendosieraggregate, the mixing process of the reactive components takes place close to the tool in an associated mixing head or mixing system. Alternatively, also in the DE102015109770A1 modified high-pressure injection plants from polyurethane technology for the preparation, mixing and injection of a thermoplastic reactive matrix disclosed. These solutions are not intended for reactive systems that already contain fillers and reinforcing agents.

Also mentioned is the processing of bulk molding compounds (BMC). As exemplified in EP0325076B1 described BMC are compacted as a fiber-filled mass with reactive matrix in a first step and then discharged by means of a piston in an injection mold. Alternatively, compression and discharge can also be effected by a screw conveyor.

The use of unreinforced components made of polyamide or cast polyamide is severely limited by their mechanical properties. In particular, for structural applications in automobiles, the use of composite components is required to achieve strength and stiffness requirements with minimal weight (Dencheva, N. et al .: Preparation of Polyamide-6-Based Thermoplastic Laminate Composites by a Novel In-Mold Polymerization Technique; J. Appl Polym Sci., 2014, DOI: 10.1002 / APP.40083) to compete with steel or aluminum solutions.

When using the injection molding process, however, the processable fiber length is limited to a few millimeters and the plasticizing process leads to a further shortening of the fibers. In addition, the method is only suitable for small wall thicknesses in the component, since otherwise the resulting cooling time after the injection process of too long duration and the process is uneconomical. Although the mechanical properties of injection-molded short glass fiber reinforced components are superior to those of pure polyamide, the performance gain is usually insufficient for structural applications. Especially in the case of thicker components, more complex geometries or the use of continuous fibers, therefore, reactive processing methods are used.

Although the use of open spraying processes and thus the use of long glass fibers in caprolactam processing is theoretically conceivable, in practice it usually fails because of the serious sensitivity of the additives used to moisture from the direct environment. Even the smallest amounts are sufficient to deactivate the catalysts used and only incomplete polymerization takes place. Although this can be remedied by rigorous inerting of the production cells, a complete enclosure and / or dehumidification of entire spray booths is very complicated, which makes the actually very economical fiber spraying process not cost-effectively feasible.

The other concepts previously presented for the processing of reactive melts with short or long glass fibers, such as the vacuum casting process, in particular have disadvantages in the use of static mixers. Here after each manufactured component an elaborate cleaning or renewal is necessary. A use under serial condition could not be demonstrated yet.

With continuous fiber-reinforced composite components, the mechanical requirements for structural components are often very easy to achieve with a low component weight, but implementation must also make sense from an economic point of view.

In particular, the generally multi-stage production of the textile or preform preforms used in the high-pressure resin injection or in-situ process (T-RTM) often has a very negative effect on the economic efficiency of the production process. In addition, the necessary preforming of the preforms sometimes entails considerable geometrical limitations in the degree of deformation that can be realized in practice.

For wet pressing, the problem of an open spray or resin application method is comparable to fiber spraying: When using caprolactam as the matrix component, complete dehumidification of the working environment would be necessary in order to prevent damage to the reactive system. In addition, the fiber volume content achievable in the wet-pressing process is significantly limited in comparison with the high-pressure injection methods.

A processing filled, so offset with fillers or reinforcing fibers, matrix components with Hochdruckdosieranlagen also brings some disadvantages. First of all, a corresponding adaptation of the machine technology is necessary, since the commonly used feed and metering pumps are not sufficient Abbrasionsbeständig and thus not suitable for the promotion of filled systems. These must be replaced by tandem double piston pump systems. Furthermore, for reasons of wear, it is usually necessary to harden individual machine components, in particular in the region of the mixing head, or to carry them out of ceramic hard materials. In addition, an inhomogeneous material discharge is often observed, especially in highly-filled systems. In particular, it may happen that during downtime aggregates sediment in the day containers and not completely dissolved or brought into the circulation. This brings an undesirable change in the recipe and thus the processing, as well as the component properties with it.

Bulk molding compounds (BMC) are mostly based on polyester or vinyl ester resins, thermoplastic systems for mass production are not yet offered.

Despite the multitude of available processes for processing fiber-reinforced molding compositions, no satisfactory solution for the processing of short- or long-glass fiber-reinforced caprolactam-based reactive systems has yet been presented. The moisture-sensitive starting materials make the use of open spraying expensive and unprofitable, a direct admixture of solid additives in high-pressure processing fails because of the necessary adaptations in machine technology, these are not cost and wear reasons for series processes not attractive.

The invention is therefore based on the object of expanding the field of application of thermoplastic resin systems, in particular those which are sensitive to environmental influences such as moisture, with regard to use with fillers, in particular fiber-containing fillers.

• - einem Mischbehälter, welcher mit der Formkavität fließtechnisch verbindbar ist,
• - einer ersten Einbringvorrichtung zum Einbringen des zumindest einen Füllstoffs in den Mischbehälter,
• - einer von der der ersten Einbringvorrichtung gesonderten zweiten Einbringvorrichtung zum gemeinsamen oder getrennten Einbringen der Komponenten des thermoplastischen Harzsystems in den Mischbehälter und
• - einem Kolben zum gemeinsamen Verbringen der im Mischbehälter befindlichen Mischung aus dem Mischbehälter in die Formkavität.

This object is achieved in terms of a device by the features of claim 1. This is done by an injection system with

• a mixing container, which can be connected to the mold cavity in a flow-technical manner,
• a first introduction device for introducing the at least one filler into the mixing container,
• - One of the first introduction device separate second insertion device for the common or separate introduction of the components of the thermoplastic resin system in the mixing container and
• - A piston for jointly bringing the mixture in the mixing container from the mixing container into the mold cavity.

With regard to a method, the object is solved by the features of claim 14. This is done by the components of the thermoplastic resin system on the one hand and the at least one filler on the other hand are introduced separately from each other in a mixing vessel and transferred by a piston from the mixing vessel into the mold cavity. In this case, the components of the thermoplastic resin system can be introduced into the mixing container before and / or after the introduction of the at least one filler.

While a large part of the presented processing methods is based on homogeneously mixing fibers and the thermoplastic resin system already during the preparation of the raw materials, the objective is to solve the problem of introducing fillers, in particular reinforcing materials, by introducing them close to the cavity. That By separately providing the components of the thermoplastic resin system and the at least one filler and mixture in the area of the mold, environmental influences, such as moisture and the like, can be minimized while at the same time a wide variety of fillers can be used.

A core aspect of the invention is a (preferably arranged close to the tool) mixing container (can also be referred to as a chamber or homogenizer). In this mixing container, both the at least one filler (for example dry fibers) and the components of the thermoplastic resin system (reactive matrix) are introduced. At the mixing container, a piston (hereinafter also referred to as injection piston) is provided by means of which a volume of the mixing container can be varied and in particular a mixture present in the mixing container can be transferred into the mold cavity of the molding tool.

The mixture in the mixing container is present as soon as one or more components of the thermoplastic resin system and the at least one filler are in the mixing container.

Optionally, the mixing container can be integrated into a sprue of the mold cavity. Furthermore, the mixing container can be connected or connected to the cavity so that a reactive mixture mixed with reinforcing agents and / or fillers can be transferred from the mixing container into the mold cavity. This movement of the filled reactive mixture serves the (injection) piston which is arranged in or on the mixing container.

By a reactive system in general, the person skilled in the art will understand a matrix consisting of one or more components, which may be mentioned below increased pressure and / or elevated temperature and / or reacted by addition of an initiator in a chemical reaction to a plastic. The chemical reaction may be a polymerization, polycondensation, polyaddition, or pericyclic reaction.

By a thermoplastic reactive system (also thermoplastic matrix system or thermoplastic resin system) in particular, the skilled person understands a reactive system which reacts in a chemical reaction to a thermoplastic material. For the most part, but not exclusively, polymerization is the reaction type. Here, the term "thermoplastic resin system" is used for such systems.

Protection is also desired for a molding machine having an injection system according to the invention. Under molding machines can be understood as transfer molding, pressing, but also injection molding and the like.

In addition, protection for the use of the injection system of the invention or the molding machine of the invention for introducing the components of the thermoplastic resin system and the filler into a mold cavity of the mold is desired.

By using the piston to dispose the mixture immediately after it has been produced, the thermoplastic resin system together with the at least one filler can be conveyed by extrusion into the mold cavity. This allows at the same time a clean filling of the mold cavity and a homogeneous distribution of the at least one filler.

Individual aspects and further developments of a method according to the invention are described below and defined in the dependent claims.

The mixing container can - in particular air and / or vacuum-tight - be closed. Environmental influences, such as moisture and foreign substances, are therefore particularly easy to avoid.

The mixing container can also be heated.

First, fillers such as fibrous material or a mixture with non-fibrous fillers, preferably dry fillers, may be introduced into the mixing vessel. These fillers may be glass fiber, carbon fibers, aramid fiber, inorganic fillers, pigments, flame retardants and the like. It is also conceivable to use cut glass fibers or glass fiber bundles (rovings) comminuted by a cutting unit.

It can be provided that the mixing container by means of a closure element - in particular airtight and / or vacuum-tight - is closed. The mixing container can thereby be closed after the fiber addition. Preferably, closing of the homogenizing device takes place together with the closing of the associated forming tool. Particularly preferably, the closing movement is performed by the movement of a horizontally or vertically closing closing unit or press. Of course, the mixing container can also be opened and closed separately from the closing unit by means of a closure element.

• - der Mischbehälter an einem ersten Bauteil des Formwerkzeugs und/oder einer ersten Formaufspannplatte einer das Formwerkzeug tragenden Formaufspannplatte einer Formgebungsmaschine so befestigbar - insbesondere montiert - ist und
• - das Verschlusselement an einem zweiten Bauteil des Formwerkzeugs und/oder einer ersten Formaufspannplatte einer das Formwerkzeug tragenden, relativ zur ersten Formaufspannplatte bewegbaren zweiten Formaufspannplatte einer Formgebungsmaschine so befestigbar - insbesondere montiert - ist,

dass ein Öffnen und/oder Schließen des Formwerkzeugs ein Öffnen und/oder Schließen des Mischbehälters bewirkt.It can be provided that

• - The mixing container to a first component of the mold and / or a first mold mounting plate of the mold-carrying mold mounting plate of a molding machine so fastened - in particular mounted - and
• the closure element is fastened to a second component of the molding tool and / or a first mold clamping plate of a second mold mounting plate of a forming machine that carries the mold and is movable relative to the first mold mounting plate - in particular mounted -

that opening and / or closing of the mold causes opening and / or closing of the mixing container.

There may be provided an evacuation device for evacuating the mixing container and / or the mold cavity. In a preferred embodiment of the invention, the mixing vessel may be evacuated prior to introduction of the thermoplastic resin system, for example, to counteract contamination of the thermoplastic resin system.

Alternatively or additionally, a gas introduction device for inerting the mixing container by means of a protective or purge gas may be provided. In such an embodiment of the invention, the mixing vessel may be rendered inert prior to introduction of the thermoplastic resin system with a protective or purge gas. Particularly advantageous may be the combination of a previous evacuation and subsequent rinsing process. For example, argon, nitrogen or dried air are suitable as protective or purge gas.

The thermoplastic resin system can already be supplied to the mixing vessel in mixed form. Alternatively, it is also possible to supply two or more reactive components to a mixing system arranged on the mixing container. Such a mixing system may be a linear mixing system, a diverter mixing head, a high pressure mixing head, a linear gating system or a static mixer.

The arrangement of the mixing system for the reactive resin system at the mixing container (for the mixture with the at least one filler) is in principle freely selectable. However, advantageous arrangements result when, for reasons of space, the component feed of the reactive resin system and the mixing container are integrated into an injection or counter-piston or the mixing container is filled from below with the reactive resin system. It can thereby be achieved an increasing filling process, and thus a displacement of residual air from the homogenization zone. With sufficient power of the evacuation device, the filling process of the mixing container can be actively supported similar to a vacuum infusion process.

The supply of the individual components of the reactive resin system can be realized in principle in any way. It can be used for example on already known systems with piston or pump delivery. In an alternative embodiment, the treatment of the reactive resin system can also be carried out in a (preferably concurrent) twin-screw extruder. In this case, for example, ε-caprolactam and suitable additives in the catchment area of the twin-screw extruder are added and homogenized. A partial or complete filler addition is already possible in this step.

In a further embodiment of the invention, the at least one filler, in particular the fibers, can already be impregnated during the introduction into the mixing container with a reactive matrix. This can be done for example by impregnation of fiber rovings in a designated bath and subsequent cutting or shredding.

The filler in the mixing container or the mixture in the mixing container can be compressible by means of the piston (injection piston). A much more homogeneous distribution of the at least one filler in the mixture can thereby be achieved. This homogenization of the mixture may be important in practice, for example to produce filled (i.e., fiber reinforced) moldings having highly reproducible (mechanical) properties.

The at least one filler, in particular the fibers, can be compressed, for example, after closing the mixing container and an optional evacuation by means of a compression stroke of the piston. Thereby, the at least one filler can be impregnated with the components of the thermoplastic resin system.

The injection of the components of the thermoplastic resin system can take place before, after or during the compression stroke. As a thermoplastic resin system, for example, two-component reactive systems, preferably caprolactam-based systems for polyamide production are used.

Compression preferably takes place before the entry of the components of the thermoplastic resin system is completed, since in this way improved impregnation of the fibers with the components of the thermoplastic resin system can be achieved. Alternatively, compression of the mixture, i. after incorporation of the components of the thermoplastic resin system and the at least one filler.

It is also possible to provide at least one additional piston, by means of which a volume of the mixing container can be changed and / or displaced. The at least one further piston can also serve for compressing the at least one filler and / or the mixture in the mixing container.

The at least one further piston can be designed as an opposing piston to the injection piston.

Embodiments with two additional pistons, which are separate from the injection piston and which preferably act counter to one another (counter-piston), are also conceivable. The position of a homogenization zone in the mixing container can be varied and shifted in such a way that there is a shut-off of the homogenization zone with respect to the cavity. In a solution with at least two additional pistons, the shut-off device can optionally be dispensed with.

In a preferred embodiment of the invention, the mixing vessel is equipped with at least one pressure sensor for measuring the internal pressure. In this way, both the pressure in the impregnation of the fibers, at a possible compression step, as well as the transfer of the filled mixture into the cavity can be measured.

By injection of the components of the thermoplastic resin system and mixing with the presented at least one filler, In particular, the fibers, creates a filled reactive system.

The impregnation of the fibers can be assisted by external aids to support the convection, such as the entry of ultrasonic waves.

But it can also be provided a stirrer to support the mixing in the mixing vessel.

After mixing in the mixing vessel, the mixture, in particular the filled reactive system, can be transferred into the mold cavity. The transfer is accomplished by the injection piston, the stroke of which can correspondingly reduce the volume of the homogenization zone. Optionally, a shut-off device can be realized between the mold cavity and the mixing container, which must be opened before the transfer of the mixture, in particular the filled reactive system, begins.

For the homogeneous transfer of the filled reactive system, a viscosity of at least 100 mPas, preferably 250 mPas and particularly preferably 500 mPas, may be advantageous. Too low a viscosity entails the risk of segregation of the filler, in particular of the fibers, and of the components of the thermoplastic resin system and thus of an inhomogeneous or insufficient transfer of the at least one filler, in particular of the fibers, into the mold cavity of the molding tool.

Already after the mixing of the components of the reactive resin system and thus preferably with entry into the mixing container, the chemical reaction of the thermoplastic resin system starts. As the reaction progresses, this usually leads to an increase in the viscosity. From a certain, material-dependent degree of conversion occurs in most reactive resin systems for fishing the reactive mass and this is no longer flowable. The duration of injection of the components of the thermoplastic resin system and the compression of the filled reactive system is preferably chosen so that a sufficient increase in the viscosity is achieved by the onset of polymerization reaction to ensure a subsequent homogeneous transfer of the filled reactive system in the cavity. The higher viscosity leads in this scenario to a reduction of sedimentation phenomena of the at least one filler, preferably the fibers. In addition, the higher viscosity significantly facilitates the sealing of the mold cavity, so that dip edge tools comparable to SMC or prepreg compression technology can also be used.

In a further embodiment of the invention, the mold cavity into which the transfer of the mixture, in particular of the filled reactive system takes place, can be evacuated beforehand. Alternatively, prior pressurization may be performed to achieve a more homogeneous flow front or injection.

Likewise, prior to transfer of the mixture into the mold cavity, reinforcing structures, e.g. Faserpreforms or honeycomb structures, but for example, metal inserts, are inserted into the mold cavity.

After completion of the transfer of the mixture into the cavity can optionally be closed again the shut-off device. The structure of the desired pressure in the cavity can be effected both by the injection piston, but also at least partially by a closing unit of the shaping machine. This makes it possible to realize the desired pressure profile in the cavity both during the transfer, but also during the progressive polymerization.

After the reaction time, both the component, and the sprue can be removed from the mold. This can be done automatically, for example, with a common demolding of component and sprue from the process engineering point of view may be quite beneficial.

• 1, 2, 3a sowie 4 bis 8 ein erfindungsgemäßes Injektionssystems in verschiedenen Verfahrensstadien und
• 3b sowie 9 bis 13 verschiedene weitere Ausführungsbeispiele mit alternativen oder zusätzlichen Maßnahmen.

Further details and advantages will be apparent from the figures and the associated description of the figures. Showing:

• 1 . 2 . 3a and FIGS. 4 to 8 show an injection system according to the invention in various stages of the method and
• 3b and 9 to 13 different further embodiments with alternative or additional measures.

1 shows a possible expression of an injection system according to the invention 1 , The mixing container is executed close to the tool and the forming tool 2 which passes through the mold plates 3a (first component of the mold 2 ) and 3b (second component of the mold 2 ) is formed in open form. The components of the reactive resin system in this case by means of flexible, heated hoses 4a and 4b to one at the mixing container 34 installed component mixing system 5 guided. The component mixing system 5 has it with tax shifters 6a . 6b lockable discharge lines 7a . 7b which are in a discharge area 8th lead. The homogenizing unit further includes an injection piston 9 and a shut-off device designed as a gate valve 10 ,

Furthermore, a closure element 36 present, with the mixing container 34 on the first component 3a of the mold 2 and the closure element 36 on the second component 3b of the mold 3b is mounted. By closing the clamping unit on which the first component 3a and the second component 3b are mounted, at the same time the mixing container 34 by placing the closure element 36 closed. For this be on 3a directed.

In 2 is the introduction of dry fibers 11 by means of the first introduction device 31 in the mixing container 34 shown. The dry fibers may be added, for example, as chopped glass fibers or as in 2 shown as continuous fibers 13 fed and in a cutting unit 12 be crushed.

In 3a are the mold 2 and the mixing container 34 in closed condition. The shut-off device 10 is also closed and prevents passage of dry fibers 11 through the sprue into the mold cavity 35 , In the mixing container 34 are the fibers 11 , The mixing container 34 is through the walls of the corresponding component, the closure element 36 and the injection piston 9 limited or formed.

In 3b is an alternative embodiment to that of 3a shown. In contrast to 3a opens the outlet area 8th in the lower part of the mixing tank 34 , Alternatively, the outlet area 8th also in the pistons 9 be integrated. This is an increasing filling of the mixing container 34 possible. In the upper area of the mixing tank 34 can be an evacuation line or vacuum line 15 (optionally lockable or with resin flow detection) may be present, via which the mixing container 34 using a vacuum pump 16 can be vented. With sufficient dimensioning of the vacuum power can over the outlet area 8th introduced components of the reactive resin system similar to a vacuum bag method through the fibers 11 be sucked.

Optionally, the mixture 33 in a mixed area 14 the mixing container by means of an ultrasonic generator 17 in addition to being homogenized or impregnated. It is also conceivable to homogenize mechanically, for example with a stirrer.

In embodiments, a compression stroke of the piston 9 and / or other measures such as an ultrasonic generator 17 or a stirrer to achieve a homogeneous distributed filler 11 can use, the mixing area 14 of the mixing container 34 also be called Homogenisierungsbereich. The mixing container 34 can then also be referred to as a homogenization device.

In 4 stay the mold 2 and the mixing container 34 in closed condition. The dry fibers 11 be through a stroke of the injection piston 9 and thus a reduction of the volume of the mixing container 34 compacted. The slider 10 also remains closed and prevents dry fibers from penetrating into the mold cavity 35 ,

Also in 5 stay form tool 2 and the mixing container 34 in closed condition. The discharge lines 7a . 7b be by moving the slider 6a . 6b (indicated by arrows) open and the components of the reactive resin system flow over the mixing area 8th in the mixing container 34 , The shut-off device 10 also remains closed and prevents penetration of the fibers 11 or the components of the reactive resin system in the mold cavity 35 ,

6 : After complete impregnation of the fibers 11 with the components of the reactive resin system, the introduction of the components by closing the slide 6a . 6b completed. To transfer the mixture 33 made of fibers 11 and the components of the thermoplastic resin system in the actual mold cavity 35 then becomes the shut-off device 10 open.

7 : After opening the shut-off device 10 in the form of a gate valve is the movement of the mixture 33 through another stroke of the injection piston 9 supports or accomplishes and the necessary pressure in the mold cavity 35 built up.

8th After the polymerization of the thermoplastic resin system, the mold 2 and the mixing container 34 be opened. From the mold cavity 35 can the composite component 19 be removed. From the sprue, the sprue can 20 be removed. Those runner areas in the mixing tank 34 , in which the reactive resin system is also cured in a controlled manner, are used as a mixing chamber remainder 21 designated and can share with sprue 20 be removed.

9 shows another embodiment of the invention, in its functionality with the injection system 1 out 1 is comparable. The injection piston 9 becomes in a plane with the mold parting plane of the mold 2 arranged to deflect the fibers 11 and minimize associated fiber damage.

10 shows a further possible form of expression of the invention. Unlike in 1 is an additional counter-piston 22 which also forms part of the wall of the mixing container 34 forms. Thus, the cavity into which the fibers are introduced, inter alia, by two pistons 9 . 22 educated. By movement of this counter-piston 22 can also be the volume of Homogenisierungsbereich 14 (alternating in the molding cycle).

In 10 became the mixing container 34 already with fibers 11 loaded, this compressed and impregnated with the components of the thermoplastic resin system, the state of the process is thus comparable with 6 ,

In this arrangement 10 to 10 can the shut-off device 10 also omitted. The fibers 11 be between the two pistons 9 . 22 compressed and wetted. Then drive both pistons 9 . 22 together to the overflow channel (preferably synchronous, see also 12 ). Only then, for example, pushes the (lower) injection piston 9 the mixture 33 into the mold cavity 35 , The same applies to the 11 and 12 ,

11 shows a further possible form of expression of the invention. In contrast to 10 is the mixing system used (second introduction device 32 ) not fixed or flanged in the wall, but in the movable counter-piston 22 integrated (Alternatively, it can also be in the injection flask 9 be integrated to allow for increasing filling).

12 : To pass the mixture 33 become injection and counter-piston 9 . 22 so moved that the mixture 33 through the sprue into the mold cavity 35 can be entered. Then, analogously to 7 the passing of the mixture 33 made of fibers 11 and the component of the thermoplastic resin system by another stroke of the injection piston 9 , the counter-piston 22 , or both pistons supported or accomplished until the mold cavity 35 completely filled.

13 shows a further possible form of expression of the invention. There are two counter-piston 22 installed, which at the same time parts of the wall of the mixing container 34 form. With these other pistons 22 let the volume of the mixing container 34 and the location of the mixing area 14 (comparable to the 9-11 ) change. The injection piston 9 is used in this embodiment of the invention only to control the shipment of the mixture 33 , In addition, optionally a slide (shut-off device 10 ) to close the sprue (see 3 ) be installed.

LIST OF REFERENCE NUMBERS

1

injection system

2

mold

3 a, b

first and second component of the mold

4 a, b

heated hoses

5

Component mixing system

6 a, b

spool

7 a, b

lockable discharge lines

8th

Outlet area (mixing area)

9

(Injection) piston

10

Shut-off

11

fibers

12

cutting

13

continuous fibers

14

mixing area

15

vacuum line

16

vacuum pump

17

ultrasonic emitter

19

composite component

20

sprue

21

Mixing chamber Rest

22

opposed piston

31

first introduction device

32

second insertion device

33

mixture

34

mixing tank

35

mold cavity

36

closure element

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 3,017,391 A [0002]
• DE 102009056653 [0004]
• EP 0995567 B1 [0004]
• DE 102009011900 B3 [0005]
• DE 2628854 A1 [0005]
• EP 3037247 A1 [0010]
• EP 2492074 A1 [0011]
• AT 515952 B1 [0012]
• DE 102015109770 A1 [0012]
• EP 0325076 B1 [0013]

Cited non-patent literature

• Ehleben, M., Cubic A.S., Mertens T., Fischer F., Vogel H .: Testable prototypes reasonably priced and fast. Plastics 05 (2017), p. 48-51 [0007]
• Wagner, P .: Processing of Caprolactam to Polyamide Moldings by the RIM Process. Plastics 73 (1983), p. 588-590 [0008]

Claims (16)

Injection system for mixing components of a thermoplastic resin system with at least one filler (11) and introducing a resulting mixture (33) into a mold cavity (35) of a molding tool (2) a mixing container (34) which can be fluidly connected to the mold cavity (2), a first introduction device (31) for introducing the at least one filler (11) into the mixing container (34), - One of the first introduction device (31) separate second introduction device (32) for the common or separate introduction of the components of the thermoplastic resin system in the mixing container (34) and - A piston (9) for jointly bringing the mixture in the mixing container (34) (33) from the mixing container (34) into the mold cavity (35). Injection system according to Claim 1 , characterized in that the mixing container (34) by means of a closure element (36) - in particular airtight and / or vacuum-tight - is closed. Injection system according to Claim 2 , characterized in that - the mixing container (34) on a first component (3a) of the molding tool (2) and / or a first mold clamping plate of the forming tool (2) supporting mold clamping plate of a molding machine so fastened - in particular mounted - and - the closure element (36) on a second component (3b) of the mold (2) and / or a first mold mounting plate of the mold (2) supporting, relative to the first platen movable second mold clamping plate of a molding machine so fastened - in particular mounted - is that an opening and / or closing the mold (2) causes an opening and / or closing of the mixing container (34). Injection system according to one of Claims 1 to 3 , characterized in that an evacuation device (15, 16) for evacuating the mixing container (34) and / or the mold cavity (35) is provided. Injection device according to one of Claims 1 to 4 , characterized in that a gas introduction device for inerting the mixing container by means of a protective or purge gas is provided. Injection device according to one of Claims 1 to 5 , characterized in that in the mixing container (34) located filler (11) or in the mixing container (34) located mixture (33) by means of the piston (9) is compressible. Injection device according to one of Claims 1 to 6 , characterized in that at least one further piston (22) is provided, by means of which a volume of the mixing container (34) is variable and / or displaceable. Injection device according to the Claims 7 , characterized in that in the mixing container (34) located filler (11) or in the mixing container (34) located mixture (33) by means of the at least one further piston (22) is compressible. Injection device according to one of Claims 1 to 8th , characterized in that a pressure sensor for detecting a prevailing in the mixing container (34) pressure is provided. Injection device according to one of Claims 1 to 9 , characterized in that at least one of the following is provided to support an impregnation and / or a thorough mixing of the at least one filler (11) with the components of the thermoplastic resin system: - Ultrasonic emitter (17) for sonicating the mixing vessel (34) located mixture ( 33) - agitator in mixing vessel (34) Injection device according to one of Claims 1 to 10 , characterized in that a shut-off device (10) for shutting off the mixing container (34) against the mold cavity (35) is provided, wherein the shut-off device (10) for moving the mixing container (34) located mixture (33) can be opened. Shaping machine with a closing unit for opening and closing a mold and an injection system according to one of Claims 1 to 11 , Use of an injection system according to one of Claims 1 to 11 or a molding machine Claim 12 for introducing the components of the thermoplastic resin system and the filler (11) into a mold cavity (35) of a molding tool (2). A method for mixing components of a thermoplastic resin system with at least one filler (11) and introducing a resulting mixture (33) into a mold cavity (35) of a mold (2), in particular using an injection system (1) according to one of Claims 1 to 11 or a molding machine Claim 12 in which the components of the thermoplastic resin system on the one hand and the at least one filler (11) on the other hand are introduced separately from one another into a mixing container (34) be transferred by means of a piston (9) from the mixing container (34) in the mold cavity (35). Method according to Claim 14 , characterized in that the at least one filler (11) comprises fiber material. Method according to Claim 15 , characterized in that the fiber material before being introduced into the mixing container (34) is impregnated with the components of the thermoplastic resin system.

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