WO2016042378A1 - Method for producing a molding material for casting cores - Google Patents

Abstract

The invention relates to a method for producing casting cores (G) or casting mold parts from a molding material (F), which is mixed from the components "molding sand (S)", "binder (B)", and optionally at least one additive for adjusting the properties of the molding material (F), wherein in the course of the method a portion of the molding material (F) is provided, introduced into a core shooter (1), and shot by the core shooter (1) into a core mold (3), which represents the respective casting core (G) or casting mold part. By gassing at least the molding sand (S) of the molding material portion with dry CO2 gas (CG) before the core shooter (1) is filled, such that the ambient air contained in the molding sand (S) of the molding material portion is displaced and such that, after the gassing, the molding sand (S) of the molding material portion has an absolute moisture content that is less than the absolute moisture content of the molding sand (S) of the molding material portion before the gassing, casting cores and casting mold parts can be simply and economically produced by using a molding material that is mixed from known components and that optimally meets the requirements that arise in practice.

Description

 Process for producing a molding material for casting cores

The invention relates to a method for producing casting cores or moldings from a molding material.

Such cores and mold parts are used as parts of casting molds for the production of casting

Castings needed.

The casting cores usually form inside

Hollows, channels and the like on the casting, while the outer contours of the casting are formed by larger mold parts that form the outer end of a mold. Filigree castings, like

Cylinder heads for internal combustion engines and the like, however, are also cast in so-called core packages, which are all composed of a variety of complex-shaped casting cores. The terms "casting core" and "casting" are therefore often used interchangeably in the jargon synonymous. Accordingly, in the present text apply to the production of

Cores given hints in the same way for moldings and vice versa, unless expressly stated otherwise.

The molding material from which casting cores and mold parts of the type in question are produced is

usually from a molding sand and a binder mixed. Optional additives for adjusting the properties of the molding material can be added to this mixture. Due to the binder, the grains of the molding sand in the finished casting core or molded part are so firmly connected to each other that the casting core or the

Shaped part with standard dimensions are sufficiently stable even under the prevailing loads in the casting operation. Further information on the molding sands and binders which are suitable for the process according to the invention can be found at www.giessereilexikon.com.

The molding sands used in practice are accordingly usually mineral substances in the size range from 0.02 to 2.0 mm grain diameter. In practice, quartz sand is used as foundry sand in the vast majority of applications. For special applications, molding sands are used, which are characterized by higher sintering points or low expansion values. These include zirconium, olivine or

Chromite sands, chamotte, corundum (AI2O3), enamel mullite (3A1 ₂ 0 ₃ -Si0 ₂ ), Cerabead and the like.

As binders are inorganic or organic

Binder systems used. Organic binder systems are based on carbon compounds, e.g. B.

Resin binder, for example, cure by gassing with a reaction gas or heat.

Inorganic binder systems are based on chemical

Compounds of metals and / or non-metals, eg. B. Water glass (sodium silicate) Na ₂ 0 -xSi0 ₂ -yH ₂ 0, bentonite (montmorillonite) A1 ₂ 0 ₃ -4Si0 ₂ -H ₂ 0, kaolinite A1 ₂ 0 ₃ -2Si0 ₂ -2H ₂ 0 or cement (CaO) ₃ -SiO 2. Curing takes place here usually by supplying heat.

About the optional added to the molding materials

Additives, the flowability or storability of the molding material mixture can be improved. A particular challenge here is that premature curing of the binder due to environmental influences must be prevented.

In practice, there is a problem with the

Processing of the above-mentioned

Components mixed molding materials, if the components used in the molding materials, ie the

Foundry sand, the binder system or, if provided, the respective additives have too high a humidity or are exposed to high humidity or high temperature. So can by high

Moisture or excessive temperature trigger premature reaction of the particular binder used.

This can on the one hand a shortening of the

Shelf life triggered, d. H. the duration

be shortened between the mixing and the

Consumption of the respective molding material without the risk of unintentional curing of the molding material

can pass.

On the other hand, there is a risk that the tools used to make the cores

or the flowability of the molding material is impaired so that the proper filling of the used for molding the respective casting core

Core form is hampered.

Finally, to inject molding materials into the core mold, increased shot pressure is needed if the molding sand of the molding material is too wet.

Against the background of the prior art, the object of the invention was to provide a method which can be used in a simple, cost-effective manner

Casting cores and moldings using a

Can be made molding material, which is mixed from the known components and thereby in the

Practice-compliant requirements optimally met.

This object is achieved in that in the production of cores or moldings at least the steps specified in claim 1 are traversed.

Advantageous embodiments of the invention are specified in the dependent claims and are explained below as the general inventive concept in detail.

In the inventive method for producing casting cores or moldings from a molding material consisting of the components "molding sand", "binder" and optionally at least one additive for adjusting the

Characteristics of the molding material is mixed, first a portion of the molding material is provided, this molding material portion then in a core shooting machine filled and shot from the core shooter finally in a core shape, which images the respective casting core or the respective casting mold part.

According to the invention, at least the molding sand of the molding material portion is then gassed with dry CO ₂ gas prior to filling the core shooting machine in such a way that the ambient air contained in the molding sand of the molding material portion is displaced. As a result of the displacement of the ambient air from the molding sand by the C0 ₂ gas and the moisture with which the ambient air is loaded, driven out of the molding sand. All other moisture-carrying gases or vapors that are contained in the molding sand are displaced when the molding sand is traversed by dry C0 ₂ gas. As a result, the molding sand portion of the molding material portion after gassing in this way has an absolute humidity which is lower than the absolute moisture content of the molding sand of the molding material portion before the fumigation. The inventively guided by the molding sand C0 ₂ gas thus distributes the moisture and it is a molding sand or a using this

Formsands mixed molding material with optimally reduced moisture.

If here it is said that "at least the

Formsand the molding material portion "is gassed with dry C0 ₂ gas, it is meant that the

Fumigation according to the invention with C0 ₂ gas can be performed as a separate, related to the molding sand alone operation, in which the molding sand is purged with C0 ₂ gas before mixing with the other molding material components. But it is also possible, the fumigation of the Formsands of the molding material portion in the ready mixed

To make molding material. In this case, the

Formstoffportion total rinsed with C0 ₂ gas. The effect achieved is the same. By gassing

with C0 ₂ gas is present between the grains of the molding sand of the molding material portion, with moisture

laden ambient air and other moisture

carrying constituents from the molding material mixture

driven and a significant reduction in the absolute

Moisture of the molding material mixture achieved.

The dehumidification achieved by the invention can be assisted by the fact that the C0 ₂ gas used for gassing the molding material has a temperature which is lower than the temperature of the molding sand of the molding material portion before the fumigation, so that the temperature of the molding sand after fumigation lower is the temperature of the molding sand before fumigation. By cooling cooled, in particular cooled to below 0 ° C C0 ₂ gas is passed through the molding sand or the molding material, not only the existing there,

expelled moisture-laden ambient air, but the molding sand or molding material cooled to temperatures at which ambient air can absorb much less moisture than at the higher temperatures with which molding materials of the type in question are usually processed in the core shop of a casting operation. About the ambient air, which enters after the inventive Begasen in the previously flushed with cold C0 ₂ gas molding sand or molding material and is cooled as well, then only much less moisture in the foundry sand / molding material can reach than that at today's high

Processing temperatures is the case. Here, the poor thermal conductivity of foundry sand has a positive effect. This is typically 0.58 W / (m * K). Due to its poor thermal conductivity, the foundry sand heats up only slowly, maintaining a low temperature throughout the process and a correspondingly low tendency to absorb new moisture. The advantages brought about by the cooling of the foundry sand brought about according to the invention, in particular the improved processability and the reduced tendency to stick, thus remain until the molding material, which is mixed from the molding sand treated according to the invention and a suitable binder and optionally further additives, becomes a finished one Core is processed, which is used in the respective mold.

The cooling and dehumidifying of the foundry sand achieved according to the invention has the further positive effect that

due to the lower temperatures of the molding sand

mixing with the binder also the curing time of the binder

Binders is delayed. Produced according to the invention

Form material has a correspondingly extended

Shelf life, which also longer storage times without

the risk of clumping of the molding material allows.

The latter proves to be especially as

advantageous if an organic binder based on a synthetic resin mixed with a hardener the molding material

is added. The through the cold molding sand

reduced temperature of the fabric slows the

Reaction between hardener and resin binder, so that the

possible storage time of the molding material compared to molding materials in total is extended, consisting of the same binder, Hardener, optional additives and molding sand are mixed, but in which no treated in accordance with the invention molding sand has been used.

Fumigation of the molding sand or molding material may occur at any convenient location on the way from providing the components of the molding material to the core shooter

occur. It has an advantageous effect here if the gassing according to the invention takes place at the earliest possible time in order to avoid premature bonding of binder and molding sand of the molding material.

Optimally, the fumigation of the molding sand before it is mixed with the designated binder, so that the moisture of the molding sand is reduced to a minimum before it hits the binder. This has a positive effect in particular when a binder is used whose reactivity decreases at lower temperatures, and the molding sand is cooled by the gassing. For this purpose, the CC> 2 fumigation, for example, immediately after the removal of the molding sand from a Formsandspeicher done.

The gassing provided according to the invention can take place in any suitable container into which the foundry sand or molding material is filled in the course of casting core production.

If the molding sand, for example after removal from the reservoir, passes through a fluidizing device in which the molding sand is flowed through in order to improve its flow behavior with a gas flow, the gassing according to the invention can take place

for example, also take place in the collecting container of this device, in which the molding sand is collected after fluidization. It is particularly useful if the fumigation of the invention in the mixing container a

Mixing device is carried out in which the components "molding sand", "binder" and "optional additives" are mixed into the molding material.

Inexpensive and without costly modifications of the device used in each case, the gassing according to the invention can then be realized if the C0 ₂ in the form

at least one piece of frozen, solid C0 _{2 is} processed. When such a C0 ₂ piece is placed in the respective container, the C0 ₂ gas stream is formed by the C0 ₂ gas formed by heating the C0 ₂ piece as a result of contact with the components of the molding material and changes its state of aggregation from solid to gaseous. The lumpy introduction of the C0 ₂ in the respective container, for example in the form of a C0 ₂ granules or in the form of one or more C0 ₂ blocks or the like. Under normal conditions carbon dioxide is certainly present in solid, lumpy form, when the temperature of each C0 ₂ piece at the time of

Filling into the respective container is at most -78.5 ° C.

At the latest by the contact of the respective C0 ₂ piece with the molding sand, the temperature of the C0 ₂ exceeds the critical for the state of aggregate state temperature.

Under normal ambient pressure conditions and elevated room temperatures, as for the inventive

Are adopted and how they usually prevail in conventional Kernmachereien, then the then onset of change in the state of carbon dioxide typical way abruptly between the solid and the gaseous phase, without causing the formation of liquid CO ₂ . At this phase transition, the C0 ₂ expands by 760 times. As a result, there is a strong outgoing from the solid C0 ₂ gas flow, so that the molding sand surrounding the C0 ₂ piece is thoroughly flushed with C0 ₂ gas and displaced in the molding sand, laden with moisture ambient air and other moisture contained in the molding sand moisture are displaced. In this way, an intensive drying of the

Formsands or mixed using this sand molding material instead. The flow properties and, consequently, the miscibility of the by the

Fumigation with C0 ₂ such dried molding sand is significantly increased compared to untreated molding sand.

With regard to the desired cooling of the molding sand or molding material, it also has the positive effect that 571.1 J / kg are required for the change in state of the C0 ₂ from the solid to the gaseous state under normal conditions. This energy is essentially removed from the molding sand in the form of heat. As a result, therefore, in accordance with the invention by the

Mixing with C0 ₂ dried molding sand introduced in particulate form significantly colder than untreated molding sand.

Among those in the practice of a conventional

Foundry conditions prevailing conditions is in the summer ambient temperatures, the temperature of the molding sand before Begasen invention with a previously present in lumpy, frozen form C0 ₂ gas is typically 30-45 ° C, whereas under the same conditions it is typically in the range of 20-30 ° C at winter temperatures. By adding in present in solid particulate form, then to C0 ₂ gas expanding C0 ₂ , the temperature of the molding sand can be lowered so far that at normal

Run the temperature of the ready mixed

Formstoffportion when filling the core shooter up to 25 ° C, typically 12 - 25 ° C, is. At low ambient temperatures, temperatures well below 12 ° C are also between 6 and 10 ° C.

for example 8 ° C reached.

Basically, the fumigation of the

Formsands or molding material required C0 ₂ gas amount based on the temperature, humidity and mass of the molding sand to calculate. For this purpose, the weight, the moisture and the temperature of the molding sand of the respective molding sand portion to be fumigated are determined and the C0 ₂ volume required for gassing or the C0 ₂ mass required for gassing as a function of the measured

Weight, the measured moisture and the measured temperature of the molding sand and the volume of each container to be fumigated determined.

In practice, temperature-controlled fumigation systems based on the respective actual temperature of the gassed molding sand or molding material have proved successful. These keep the fumigation with cold C0 ₂ gas upright until the temperature of the fumigated

Formsands or molding material a target lower limit

reached . Alternatively or additionally, the fumigation can also be controlled moisture-dependent. This will be

recorded continuously or at certain intervals, the humidity of the gassed molding material or foundry sand and also here the fumigation with C0 ₂ gas maintained until the moisture has reached a predetermined target minimum value.

If an estimate is to be made of the mass MC0 ₂ required for the fumigation at C0 ₂ as a function of the mass MF of the molding sand to be fumigated, this can be done according to the formula MC0 ₂ ^ 0.01 × MF. It should be noted that even a gassing with comparably small C0 ₂ -volume streams has a positive effect on the processing properties of the molding material.

The effect achieved by the invention can be further enhanced by filling the molding material portion with molding sand from a storage container into a portioning container that is actively cooled to a temperature lower than the temperature of the molding material when it is removed from the mold

Reservoir.

An optimal function of the core shooter used for shooting the cores and moldings, which, as usual, has at least one shooting nozzle from which the molding material is shot into the core mold, can be achieved that the core shooter at least in the shooting nozzle in itself

known manner cooled to an operating temperature which is lower than the temperature of the

Formstoffportion in their provision.

Typically, the temperatures are the

Core shooter for this purpose in the shooting nozzle at up to 30 ° C, with temperatures of up to 27 ° C, especially 18-25 ° C, lead to good results.

As a result, the invention provides as conceivable

simple and inexpensive to implement means a molding material for the production of foundry cores available, which has optimal processing properties. The molded material produced according to the invention also makes it possible, by its low moisture content qualitatively

high quality castings with optimized

 Surface quality, since the risk of penetration of the casting surface by steam, which in the respective casting core as a result of the casting

could supply supplied heat is minimized.

The invention is based on a

Embodiment explained in more detail. Show it:

Fig. 1 shows a plant for the manufacture of casting cores in

 a schematic representation;

Fig. 2 shows the time course of the temperature and

 Damp from in the shooting head one

Core shooter pending sand molding. The plant A shown in FIG. 1 is part of a core shop, not shown here further, which produces casting cores G for casting molds in continuous operation, which are intended for the production by casting of cylinder heads from an aluminum melt.

The installation A comprises a core shooting machine 1, which shoots a portion of molding material F into the mold cavity G forming mold cavity 2 of a core mold 3.

For this purpose, the core shooting machine 1 includes in itself

a known manner, several shooting nozzles 4, which dive during shooting in associated openings of the core mold 3. The shooting nozzles 4 are supported by a weft plate 5, on which in turn sits a firing cap 6. The

Shot cap 6, the shooting plate 5 and the shooting nozzles 4 are connected to a cooling system 7, which

Shot cap 6, the shooting plate 5 and the shooting nozzles 4 at a temperature of about 22 ° C holds. The firing hood 6 bounds with the weft plate 5 a space into which the portion of molding material F to be shot into the core mold 3 is filled via a filling funnel 8.

The hopper 8 may also be connected to an active, not shown cooling device to keep its coming into contact with the filler surfaces at a temperature of 22 ° C maximum.

The molding material F passes through a suitable, also known per se, here for the sake of clarity not shown conveyor of a

Mixing device 9 in the hopper 8. In the

Mixing device 9 is the molding material F in one Mixing container 10 mixed from a portion of molding sand S and a binder B. The molding sand S is conventional quartz sand obtained in whole or in part by recycling foundry cores G destroyed during the coring of the respective casting, and one

Reuse has been supplied. The binder B is, for example, a conventional cold-binder process by gassing with a reaction gas-curing organic binder system, also known from practice, in the hot-box process by

Heat-curing binder system or a

water-based inorganic binder system.

If necessary, additives can be added to the molding material F to positively influence its processing properties.

The molding sand S is in a storage silo 11th

held, which contains the daily needs of the core making of molding sand S. The temperature of the molding sand S in the storage silo 11 is 38-40 ° C.

From the storage silo 11, the molding sand S is filled via a portioning device 12 into the mixing container 10 of the mixing device 9. The portioning device 12 can likewise be connected to a cooling device 13, which cools the surfaces of the portioning device 12 that come into contact with the molding sand S to such an extent that the molding sand S portioned in the portioning device 12 is cooled to a temperature of 32-35 ° C. The gassing according to the invention takes place in the course of

Mixing the molding material F in the mixing container 10 of the commercially available, conventionally trained

Mixer 9 instead. First, a portion of cooled to at least -78.5 ° C, lumpy

C0 ₂ dry ice C is added to the empty mixing container 10. Subsequently, the mixing device 9 is started and waiting in the portioning device 12 portion of molding sand S in a conventional manner in the

Drizzled mixing tank 10, so that the molding sand S and the C0 ₂ dry ice C are intensively mixed together. As a result of the associated warming, the C0 ₂ dry ice C suddenly changes its state of aggregation from solid to gaseous under strong expansion. This process continues until the C0 ₂ dry ice C is completely gaseous. The expanding C0 ₂ gas CG flushes through the molding sand S and displaces in the molding sand S existing ambient air and moisture.

At the same time, in the example considered here, when falling in, the temperature of the molding sand S still drops to 43 ° C. to 15 ° C. at the end of the premixing process. This is achieved when all in the

Blender 9 given C0 ₂ dry ice C is vaporized. The residual moisture remaining in the molding sand after pre-mixing is less than 1 g / m ³ immediately after mixing, compared to a moisture content of 47 g / m ³ before premixing.

Via a temperature measuring device 14, the temperature of the molding sand S in the mixing container 10 is continuously monitored during mixing and, if necessary, further lumpy C02 ~ dry ice C in the mixing container 10, until the molding sand S has reached the target temperature of 15 ° C.

Upon reaching this target temperature is the

required amount of binder in the mixing device 9, the molding material F mixed ready in the usual way and promoted to the core shooter 1.

For example, as a molding sand 24 kg quartz sand with a moisture content of 47 g / m ³ and a temperature of about 42 ° C by mixing 0.6 kg of a

conventional binder system consisting of 0.5 kg of an organic resin and 0.1 kg of one as well

conventional hardener is formed, to be processed into a serving of molding material F, will be about 1 kg

C0 ₂ dry ice C is required to cool the molding material F to 15 ° C and the absolute moisture content of the molding material F measured at the end of the mixing process to less than

1 g / m ³ to reduce. Measurements after a storage period of

2 hours showed that so by the

Fumigant according to the invention dehumidified and cooled molding material F has an absolute humidity of not more than 15 g / m ³ and a temperature of 25 ° C.

Through the use of molding material F cooled and dehumidified by the C0 ₂ gasification according to the invention, the proportion of defective casting cores G

be reduced by more than 70%, typically 70-80%, regardless of the climatic conditions. For example, in practice testing, the reject rate dropped from an average of 10% to 2 - 3%. From inventively treated molding material F produced

Gießkerne G also showed an improved

Surface texture, density and stability.

The number of shots scored with the core shooting machine 1 per hour operated with inventive molding material F was up to 30% higher than that of a core shooting machine operated with untreated molding material F.

Type be increased. Because of the drastic

lowered adhesion of the molding compound F for bonding, the time intervals in which the shot nozzles had to be cleaned could be extended 15 to 20 times compared to the maintenance intervals, in those operated with untreated molding material

Core shooting machines of the same design must be cleaned.

In Fig. 2 is an example of the development of

Temperature T and humidity F shown in the firing head of a core shooting machine, not shown over time. During a first transient phase A is the

Calibrated measuring apparatus. In the following phase B, the firing head has been loaded in accordance with the invention with C0 ₂ gassed molding sand. The absolute

Moisture here was in the range of 15-20 g / m ³ at a molding sand temperature of 21-25 ° C. Subsequently, the shooting head with conventional, not in

according to the invention gassed molding sand has been charged. In this case, over a phase C of the still existing in the shooting head, processed in accordance with the invention molding sand has been gradually replaced by conventionally untreated molding sand. Accordingly, within In phase C, the temperature T and moisture F of the molding sand in the weft head increased until the moisture reached a stable level of 25-28 g / m ³ and the temperature of the molding sand was 28-31 ° C.

REFERENCE NUMBERS

1 core shooter

 2 mold cavity of the core mold 3

 3 core shape

 4 shooting nozzles of the core shooting machine 1

 5 shooting plate of the core shooting machine 1

 6 firing hood of the core shooting machine 1

 7 Cooling system of the core shooting machine 1

 8 hopper

 9 mixing device

 10 mixing container of the mixing device 9

 11 storage silo

 12 portioning device

 13 Cooling device of the portioning device 12

14 temperature measuring device

A plant for the production of foundry cores G

 B binder

C lumpy C0 ₂ dry ice

CG C0 ₂ gas

 F molding material

 G casting cores

 S molding sand

Claims

P AT E N T IN P R E C H E 1. A method for producing cores (G) or  Casting parts of a molding material (F), consisting of the components "molding sand (S)", "binder (B)" and optionally at least one additive for adjusting the In the course of the process, a portion of the molding material (F) is provided, filled into a core shooting machine (1) and shot from the core shooting machine (1) into a core mold (3) containing the respective casting core (G) or the respective casting mold part, characterized in that at least the molding sand (S) of the molding material portion before filling the core shooting machine (1) with dry C0 ₂ gas (CG) is gassed, so that in the molding sand (S) of the molding material portion displaced ambient air is displaced and the molding sand (S) of the molding material portion after the gassing has an absolute humidity, which is lower than that  absolute humidity of the molding sand (S) of the  Formstoffportion before fumigation. The method of claim 1, d a d u r c h characterized in that the C0 ₂ gas has a temperature which is lower than that Temperature of the molding sand (S) of the molding material portion before the fumigation, so that the temperature of the molding sand (S) after fumigation is lower than the temperature of the molding sand (S) before fumigation. 3. The method of claim 2, d a d u r c h characterized in that the temperature of the C0 ₂ gas (CG) is less than 0 ° C. 4. Method according to one of the preceding claims,  The molding sand (S) of the molding material portion is placed in a container (10) prior to filling the core shooting machine (1) and the gassing takes place in the container (10). 5. The method of claim 4, d a d u r c h  If the container is a mixing container (10), then the components of the  Formstoffs (F) before filling the core shooter (1) are mixed. 6. The method of claim 4 or 5, d a d u r c h characterized in that the molding sand (S) is fluidized in the container. 7. The method according to claim 3 and one of claims 4 to 6, characterized in that at least one C0 ₂ piece (C) deep-frozen, present in solid form C0 ₂ in the container (10) is given, and that the molding sand (S ) C0 ₂ gas stream through the C0 ₂ gas (CG) is formed, which is characterized in that the C0 ₂ piece (C) is heated as a result of contact with the components of the molding material (F) and its state of matter from solid changes to gaseous. 8. The method of claim 7, d a d u r c h in that the temperature of the C0 ₂ piece (C) at the time of filling into the container (10) is at most -78.5 ° C. 9. Method according to one of the preceding claims, characterized in that the mass used for the gassing MC0 ₂ at C0 ₂ as a function of the mass MF to be fumigated Formsands (S) according to the formula MC0 ₂ ^ 0.01 x MF is determined. 10. The method according to any one of the preceding claims, characterized in that for the provision of the molding material portion molding sand (S) from a reservoir (11) in a portioning container (12) is filled, which is actively cooled to a temperature is, which is lower than the temperature of the molding material (F) when removing from the reservoir (11). 11. The method according to any one of the preceding claims, characterized in that the weight, the humidity and the temperature of the molding sand (S) of the molding sand Portionsung determined and required for gassing C0 ₂ volume depending on the measured weight, the measured moisture, the measured temperature of the molding sand (S) and the volume of Container is determined. 12. The method according to any one of the preceding claims, characterized in that the molding sand (S) of the molding material portion after the gasification with the C0 ₂ gas (CG) with the binder (B) and the optionally added additives is mixed. 13. The method according to any one of the preceding claims, characterized in that the temperature of the molding sand (S) before Begasen with the C0 ₂ gas 20 - 45 ° C and the temperature of the finished  mixed Formstoffportion when filling the  Core shooter (1) up to 25 ° C. 14. The method according to any one of the preceding claims, characterized in that the core shooting machine (1) has at least one shooting nozzle (4) from which the molding material (F) in the core shape (3) is shot and that the  Core shooter (1) at least in the area of  Shooting nozzle (4) is cooled to an operating temperature which is lower than the temperature of the  Formstoffportion in their provision. 15. The method of claim 14, d a d u r c h  e n c ia n, the s  Operating temperature is less than 30 ° C.