DE202019103481U1 - Mold insert for a mold part, suitable for a method for producing a molded part, and molded part - Google Patents

Abstract

Mold insert (120. 160) for an apparatus for producing a molded part with a molded part mold (110, 150), in particular a foam or Galvanoform, with an upper part (160) and a lower part associated therewith (120), which form a cavity the mold part shape, via the mold insert (120, 160), a material introduced into the cavity, in particular a foam, imprints a mold, characterized in that the mold insert (120, 160) has a surface, in particular full surface, on the mold part mold (110, 150) is adapted so that the mold part (110, 150) receives the mold insert (120, 160) in a form-fitting manner, so that the mold part mold (110, 150) acts uniformly on the mold insert (120, 160), so that in the adapted state a volume-reduced cavity (111) is formed, and the mold insert (120, 160) contributes to the molding of the introduced material.

Description

The invention relates to a mold insert for a molded part, in particular a foam or Galvanoform, with an upper part and a lower part associated therewith, with a cavity, in particular a die, wherein the mold part shape in the cavity introduced material, in particular a foam, a Shape is imprintable.

For the production of foam moldings from foam systems such as soft, semi-hard, hard and integral foam foaming molds are usually used, which are made of different base materials, depending on the purpose and the required expression or service life. For example, for prototype or pilot series molds plastic, plastic casting resins or plastic sheets are used, while for serial purposes or for the application of high numbers and complex parts, molds made of aluminum and / or steel are used.

These forms usually consist of a lower and upper shell, which are connected with lateral hinges. Closed form the two "halves" a desired cavity, which is also called cavity and forms a negative of the required molding.

To remove "undercuts", ribs or the like, slides and inserts or the like are used, which are inserted and operated manually, semi-automatically and also fully automatically. When the mold is open and / or when the mold is closed, a processed foam system is introduced into the cavity through a sprue system via a mixing head.

A negative or undesirable characteristic of the aforementioned systems is that the foam adheres to the aluminum or the steel of the foam molds and often can only be removed mechanically again.

In order not to damage the parts during demolding or to remove them intact, various release agents are used. These release agents prevent "sticking" of the foam parts to the surface of the molds. Most wax-based release agents are used, which are liquefied by solvents to apply these by means of a spray gun or brush on the molds.

These release agents must be applied before each cycle. The solvent volatilizes and the wax leaves a relatively thin layer on the surface of the molds.

This is an independent process, which must be stable, so that a consistent quality of the parts can be guaranteed. The release agents are usually manually introduced by a worker at the foaming by spray gun and the resulting spray and solvent vapors must be removed by suction.

Due to the repetitive introduction of the separating layer, in particular at small radii or the ribs, a thicker wax layer is formed, which must be removed on a regular basis.

The introduction of the release layer, as well as the regular removal of the wax residue means a considerable time and cost, which is associated with a recurrent interruption of the production process.

On the foam parts themselves also remains a thin release agent layer. This layer is only problematic if the part is not to be further processed, so it is a finished part.

However, should the foam parts subsequently be laminated, this layer of release agent residues makes it difficult to bond the foam to the laminating material. Laminating takes place for example with a leather or a foil. Thus, the foam part must be cleaned before laminating.

The release agents described are also used in the production of spray skins or thermoformed films. For the production of spray skins and deep-drawn foils often so-called electroforming are used. By means of these electroforming surfaces, for example, surfaces for door panels, control panels or center consoles are made.

For example, two-component polyurethane systems are sprayed onto these electroforms. This forms a skin whose thickness varies depending on the entry quantity and after appropriate reaction time of the form is removed. In order to be able to remove or remove the resulting skin, it is necessary, as already explained above, to use release agents which are introduced either manually or robotically.

The spray skins thus produced are often foamed with a carrier, resulting in more complex components. Again, it must be ensured that the spray is freed of any release agents.

Another disadvantage is that electroforming is very expensive to manufacture. This is due, among other things, to the fact that these shapes are often imprinted with a surface grain which, for example, is supposed to impress a leather-like grained surface on the skin to be produced. Even the slightest touch by a worker can destroy such Galvanoform.

Furthermore, molded foam parts are often coated with so-called coatings. Such a coating is a protective layer. Without this protective layer, the surfaces of foam moldings tend to fade and become brittle when exposed to UV light. The protective layer prevents the action of UV light, for example by absorbing the UV radiation.

Coatings are, for example, lacquers, which are introduced into the foam molds before the foaming processes, in order to then homogeneously combine with the foam. After demolding the foam is then practically coated with the "coat". The reject rate of coated foam parts is relatively high and can be up to 30% or more. Release agents must also be used for clean removal.

In the manufacture of carpets, as used for example in vehicle construction, the back of the carpet - usually a thermally preformed carpet - provided with a relatively thin-walled foam layer. The aim of this measure is to increase pedaling comfort, to absorb tolerances, to prevent fraying and to achieve noise insulation. In order to remove this large-scale foam after the reaction time the tool is usually a thin-walled film, which was previously thermoformed, inserted as a release medium on the appropriate tool side and disposed of after removal. This process is labor intensive and costly.

The object of the invention is to improve the state of the art.

The object is achieved by a mold insert for a molded part, in particular a foam or Galvanoform with an upper part and a lower part associated with this, with a cavity, in particular a die, wherein with the mold part introduced into the cavity material, in particular a foam, a Shape can be imprinted, wherein the mold insert can be arranged on the mold part, so that in the arranged state, a volume-reduced cavity is formed and the mold insert contributes to the imprinting of the material.

Thus, a rapid replacement of the actual shaping cavity can be ensured.

Furthermore, the reaction time can thus be waited for independently by the removal of the mold insert from the mold part form, while the next foam part is already produced by newly introduced mold inserts into the mold part mold.

The following concept is explained:

The "mold part mold" is a custom molded mold part made of, for example, aluminum or steel, which is usually used for producing a molded article. In particular, the molded part mold comprises a "foam mold" with an upper part and a lower part associated therewith. In this case, the upper and lower part can be separated from each other to remove a molded part. In addition, in the closed state of the foam mold foams can be injected, which simulate the form formed by the upper part and lower part, whereby the foam molding is formed.

Furthermore, the mold part form can be designed as Galvanoform. The Galvanoform can also have an upper part and a lower part associated therewith, usually only one upper part or a lower part is used. Electroforming can be used to produce thin-surface structures such as skins. High-quality skins are produced by etching the electroform, so that it has a so-called scarring. Thus, skins can be produced which have, for example, a leather-like surface structure.

The "mold insert" may completely fill the mold part or cover only parts of the mold part mold. Ultimately, the mold insert may be a plate or other physical object which is demolded together with the molding.

The "cavity" is a cavity which is formed by the mold part shape. In the case of a one-part mold part, the term "die" is used in this context in particular. The cavity and the die have in common that when introducing a material, such as a foam, the shape of the cavity or the die is simulated by the material.

The "introduced material" is in particular a liquid or foamed material, which forms a solid body by a curing process. For example, the material may be a plastic foam, in particular a soft, semi-hard, hard and / or integral foam. In addition, epoxy resins can be used as incorporated material. Also can soaked Fibers such as epoxy impregnated fiber mats (prepregs) are introduced, which harden in the cavity. Also included may be powdery materials such as those used in a slush molding process.

"Anordenbar" in this context means, in particular, that the mold insert is adapted to the mold part shape, so that the mold part form receives the mold insert and by means of the mold insert, the molded part to be produced can be produced. Preferred is a positive-locking arrangement, so that the mold part form can act uniformly on the mold insert.

In order to produce moldings without a release agent, a surface of the mold insert assigned to the volume-reducing cavities can have little or no interfacial tension. In this case, the interfacial tension is determined both by the material introduced and by the material of the associated surface. The low interfacial tension relates in particular to the materials steel and aluminum, which form the surface of a conventional molded part.

Since the quantitative values for the interfacial tension depend on the system used, which interacts with the surface, it is sufficient that the above condition is satisfied for the particular system. Particularly in the case of the "foam" system, it is important that in the case of the cured foam, the interfacial tension between cured foam and the surface of the mold insert be lower than aluminum or steel.

In the literature, instead of the interfacial tension is often spoken of a surface tension. These terms are to be considered synonymous in the following.

Since only the material property of the surface of the mold insert is essential for the release agent freedom, the surface of the mold insert assigned to the volume-reducing cavity can be coated.

In a further embodiment, the volume-reducing cavity associated surface of the mold insert is formed by a plastic. Thus, material alternatives to aluminum and steel can be provided.

Low interfacial tensions or interfacial tensions can be achieved in that the surface of the mold insert assigned to the volume-reducing cavity is formed by a polyolefin, in particular by polyethylene.

In a further embodiment, the mold insert has a temperature-conducting element, which is manufactured in particular from metal. By means of this temperature-guiding element, the temperature gradient from the material into the mold insert can be increased or reduced to form the actual mold part, for example made of aluminum or steel. Thus, both heating of the material in the mold insert and effective cooling of the material in the mold insert can be realized. Preference is given to using metals with good heat conduction properties, it also being possible to use other heat conductors or insulators.

In order to also ensure a good thermal conductivity of the mold insert, the material thickness of the mold insert can be between 0.8 mm and 8 mm, and particularly preferably about 2.5 mm. It is particularly advantageous for the heat conduction to ensure very low material thicknesses.

In a further embodiment, the mold insert is manufactured as an injection-molded part. As a result, mold inserts can be produced in large quantities, which significantly reduces costs.

In order to ensure a defined fastening and a defined release of the mold insert in or from the mold part form, the mold insert may have a fastening element which enables a releasably fixed arrangement with the mold part form. In particular, clamping or screwing devices are possible embodiments for the fastening element.

In order to impart stability to the mold insert, the mold insert can form a carrier structure.

In order to reduce weight or to form a specific heat insulation, the support structure may have cavities.

In another embodiment, joined part mold inserts form the mold insert. Thus, in particular large-scale molded parts such as carpet coverings can be made in automobiles.

In order to form as homogeneous a mold insert as possible with the part mold inserts, the part mold inserts can have connecting elements which can form a stable mold insert. The connecting elements can for example form a kind of tongue and groove principle. Also screw with associated threads are feasible.

In a further aspect of the invention, the object can be achieved by a device for producing a molded part with a molded part mold having a cavity with which an introduced material can be imprinted with a mold which can be arranged in the molded part mold according to a previously described mold insert, so that when arranged Form insert a volume-reduced cavity is formed, which imprints an introduced material a volume-reduced form. Thus, molded parts can be produced which use the previously described advantageous properties of the mold insert.

In order to ensure an optimum connection of molded part shape and mold insert, the volume-reduced cavity can express a shape of the molded part to be produced, wherein the cavity formed by the molded part shape is increased by the material thicknesses of the mold insert.

In a further embodiment, the molded part has an associated receptacle for the fastening element. Thus, advantageously, a releasable connection between mold part and mold insert can be ensured.

In order to provide material alternatives for the molding die, the molding mold may be made of a metal, in particular stainless steel, steel, aluminum and / or magnesium, or a metal alloy.

In order to form a cavity with an optimal three-dimensional shape, the molded part form can have an upper part and a lower part, wherein a mold insert can be introduced both in the upper part and in the lower part or in both.

In a further aspect of the invention, the object is achieved by a molded part, in particular a foam molding, which has been manufactured with a device described above.

• - Einbringen eines zuvor beschriebenen Formeinsatzes in die Formteilform einer zuvor beschriebenen Vorrichtung,
• - Einspritzen eines formbaren Materials, insbesondere eines Schaumes, in die volumenverringerte Kavität, sodass die volumenverringerte Kavität dem Material die Form des Formteils aufprägt, sodass ein Formteil entsteht,
• - Entnehmen des Formteils,
• - Entfernen des Formteils.

In a further aspect, the object of the invention can be achieved by a method, which is not claimed here, for producing a molded part, in particular a foam molding, the method comprising the following steps:

• Inserting a previously described mold insert into the molded part mold of a previously described device,
• Injecting a moldable material, in particular a foam, into the volume-reduced cavity, so that the volume-reduced cavity imprints the material on the shape of the molded part, so that a molded part is produced,
• - removing the molding,
• - Remove the molding.

In order to use the mold insert several times, further moldings can be produced in the method prior to removal of the mold insert.

In a further embodiment, a coating layer is applied prior to the injection of the moldable material on the mold insert, which is impressed during manufacture of the molding. Thus, there is a molded part, which forms a solid connection with the coating layer. Thus, the molding is protected, for example, from harmful UV radiation.

To produce composite components, a molded part carrier, in particular a plastic carrier, can be introduced into the cavity or into the volume-reduced cavity prior to the injection of the moldable material. It is only necessary to ensure that the molded part carrier can form a connection to the material in the cavity.

In a further embodiment, the mold insert is replaced by a further mold insert after removal of the molded part. So can be dispensed with an exchange of moldings and it comes only the cheaper mold inserts for use.

To further reduce costs, a used mold insert can be cleaned and reused.

In an additional aspect of the invention, the object can be achieved by a molded part which has been produced according to a method described above.

In another aspect, the object is achieved by a mold part suitable for a method for producing a molded part, wherein release agents of any kind are avoided. Thus, the cost of release agent in manufacturing a molded article can be reduced. Release agents are all substances, liquids, powders or the like, which are used in the manufacture of the molding, without being necessary for the actual function of the molding and only serve to better demolding.

In a final aspect of the invention, the object can be achieved by a molded part, which is manufactured according to the preceding method.

Furthermore, the invention will be explained in more detail with reference to embodiments.

• 1 eine schematische Darstellung eines Werkzeuges mit separierten Formteilformen und Formeinsätzen zum Herstellen eines Formteils,
• 2a eine schematische Darstellung eines Schnittes durch ein Werkzeug für ein Schaumformteil mit Kunststoffformteilträger,
• 2b einen vergrößerten Teilausschnitt der 2a mit einem verfülltem Schaumsystem und einem Coating,
• 3a eine schematische Darstellung eines Schnittes durch ein Werkzeug für ein Schaumformteil,
• 3b einen Teilausschnitt des Werkzeuges aus 3a,
• 4a eine schematische Darstellung eines thermogeformten Teppichs für Fahrzeugböden,
• 4b eine reduzierte schematische Darstellung eines Schnittes eines Werkzeugs zum Herstellen des thermogeformten Teppichs aus 4a,
• 5 eine schematische Darstellung eines Galvanoformwerkzeugs zum Herstellen von Sprühhäuten,
• 6a eine schematische Darstellung eines Schnittes durch ein Werkzeug zum Herstellen eines Lenkrades und
• 6b einen vergrößerten Ausschnitt des Werkzeuges aus 6a

It shows

• 1 a schematic representation of a tool with separated mold part molds and mold inserts for producing a molded part,
• 2a a schematic representation of a section through a tool for a foam molding with plastic mold carrier,
• 2 B an enlarged part of the 2a with a filled foam system and a coating,
• 3a a schematic representation of a section through a tool for a foam molding,
• 3b a partial section of the tool 3a .
• 4a a schematic representation of a thermoformed carpet for vehicle floors,
• 4b a reduced schematic representation of a section of a tool for producing the thermoformed carpet from 4a .
• 5 a schematic representation of a Galvanoformwerkzeugs for producing spray skins,
• 6a a schematic representation of a section through a tool for producing a steering wheel and
• 6b an enlarged section of the tool 6a

A basic form of a tool according to the invention ( 1 ) consists of a molded part (lower part) 110 , one of the mold part (lower part) 110 assigned mold insert (lower part) 120 and a molded part (upper part) 150 , one of the molded part (upper part) 150 assigned mold insert (upper part) 160 ,

The mold part (lower part) 110 has a partial cavity 109 on. The same applies analogously to the molded part form (upper part) 150 (not shown). Both partial cavities together form a cavity. The mold insert (lower part) 120 has a volume reduced Teilkavität 111 on. The same applies to the mold insert (upper part) 160 (not shown). Both volume-reduced partial cavities form a volume-reduced cavity.

Both the mold part (lower part) 110 as well as the molding part (upper part) 150 are designed so that the assigned mold inserts 120 . 160 through the molding parts 150 . 110 be recorded positively.

Be shaped part (upper part) 150 and molded part (lower part) 110 with the mold inserts 120 . 150 assembled, forms the mold, which is used for producing a molded part.

A tool 201 for making a on a plastic mold carrier 220 attached foam molding ( 2a) includes a molded part (upper part) 150 and a molded part (lower part) 110 , In the mold part form 110 is the mold insert 120 brought in. The thereby forming positive connection is through the clamp connection 240 fixed. In the mold part (upper part) 150 is a plastic carrier 220 arranged. At this plastic mold carrier 220 During manufacture, the foam molding (not shown) is attached. The assembled tool forms a volume-reduced cavity 222 out.

For producing a component with a plastic carrier, foam molding and a coating covering the foam molding 270 becomes the mold insert 120 of the tool 201 covered with a coating material (see 2 B) , In the mold part form 150 becomes the plastic mold carrier 220 brought in. Molding part (upper part) 150 and molded part (lower part) 110 with associated mold insert 120 are closed. In the volume-reduced cavity 222 becomes the foam system 290 brought in. The foam system 290 makes with the coating 270 and the plastic mold carrier 220 a solid connection. As the mold insert 120 made of polyethylene, remain during removal no or only small residues of the coating 270 on the mold insert 120 stick.

With the tool 301 becomes a foam molding 333 made (see 3a and 3b) , Both the mold insert (upper part) 160 as well as the mold insert (lower part) 120 are made of polyethylene. The two mold inserts 120 . 160 be through the associated molding parts 150 and 110 accurately recorded. The clamp connections 240 ensure a sufficiently strong connection of the molding parts 150 . 110 with the mold inserts 120 . 160 , In the volume-reduced cavity 333 a foam is sprayed, so that the foam molding 333 forms. Through the material selection for the mold insert 120 . 160 No residues of the foam molding are formed on the mold inserts 120 . 160 ,

With the mold insert 160 become thermoformed carpets 405 manufactured for vehicle floors (see 4b) , This is done using a tool like the one in 4b is shown reduced. A carpet for vehicle floors has in principle three layers. For a foam back 444 , a foam backing this 444 associated Teppichägrägergewirke 442 and the sling 448 which forms the actual carpet surface for the user. In the present case there is the Schlingware 448 made of velor. The at the Schlingenware 448 attaching mold part form is not shown. However, this molding form limits the expansion possibilities of the carpet carrier fabric 442 and the sling 448 , The one for the foam back 444 required cavity is through the mold insert (lower part) 160 educated. This is made of polyethylene.

In the cavity, a foam is introduced, so that a foam backing 444 which forms a firm connection with the carpet carrier knitted fabric 442 formed. Through the material selection of the mold insert (lower part) 160 remain small remnants of the foam back 444 on the mold insert (lower part) 160 so that the thermoformed carpet 405 for vehicle floors essentially release agent is produced.

With the tool 501 sprayed skins are made (see 5 ). The tool consists of a Galvanoformteil (upper part) 550 and a Galvanoformeinsatz assigned to this (upper part) 560 , The Galvanoformeinsatz (upper part) 560 is through a spray nozzle 565 sprayed with a two-component polyurethane system. The polyethylene mold insert (upper part) 560 has a scarring, which imparts a leather-like structure to a sprayed-on skin.

The spray nozzle 565 distributes the polyurethane system so that over time a thin skin on the surface of the Galvanoformeinsatzes (top) 560 formed. When demoulding, this skin is from the Galvanoformeinsatz (top) 560 deducted. Through the material selection for the Galvanoformeinsatz (upper part) 560 no residues of the skin produced remain on the Galvanoformeinsatz.

With the tool 601 a steering wheel is made. The tool 601 has a molded part (upper part) 110 and a molded part (lower part) 150 on. These molding forms 110 . 150 each take a mold insert 120 . 160 on. In addition, the tool points 601 a clearance for the steering wheel hub 659 on. For stability is before foaming a steering wheel core 667 in the tool 601 appropriate. In the forming volume-reduced cavity 666 the foam system is sprayed in, so that the steering wheel is formed.

LIST OF REFERENCE NUMBERS

109

partial cavity

110

Molding front (lower part)

111

Volume-reduced partial cavity

120

Mold insert (lower part)

150

Molding front (upper part)

160

Mold insert (upper part)

201

Tool for producing a foam molding attached to a plastic mold carrier

220

Plastic molding carrier

222

Volume-reduced cavity

240

clamp connection

270

coating

290

foam system

301

Tool for producing a foam molding

333

Foam molding

405

Thermoformed carpet

444

foam backing

446

Teppichträgergewirke

448

Sling fabric (suede)

501

Tool for making a skin

550

Galvanoformteil front (top)

560

Galvanoformeinsatz (upper part)

565

nozzle

601

Tool

659

Free space for steering wheel hub

666

foam system

667

steering wheel core

Claims (23)

Mold insert (120. 160) for an apparatus for producing a molded part with a molded part mold (110, 150), in particular a foam or Galvanoform, with an upper part (160) and a lower part associated therewith (120), which form a cavity the mold part shape, via the mold insert (120, 160), a material introduced into the cavity, in particular a foam, imprints a mold, characterized in that the mold insert (120, 160) has a surface, in particular full surface, on the mold part mold (110, 150) is adapted so that the mold part form (110, 150) the form insert (120, 160) receives a form-fitting, so that the mold part form (110, 150) uniformly on the mold insert (120, 160), so that in the adapted state, a volume-reduced cavity (111) is formed, and the mold insert (120, 160) contributes to the molding of the introduced material. Mold insert (120, 160) after Claim 1 , characterized in that the mold insert (120, 160) has at least one fastening element. Mold insert (120, 160) after the Claims 1 - 2 , characterized in that at least one fastening element in the form of a clamping device or a screw device is present. Mold insert (120, 160) after the Claims 1 - 3 , characterized in that the mold insert has a support structure. Mold insert (120, 160) after the Claims 1 - 4 , characterized in that the mold insert has a carrier structure with cavities. Mold insert (120, 160) after the Claims 1 - 5 , characterized in that the mold insert has connecting elements. Mold insert (120, 160) after the Claims 1 - 6 , characterized in that the connecting elements are designed according to a tongue-and-groove or screw principle. Mold insert (120, 160) according to one of the preceding claims, characterized in that a surface of the mold insert (120, 160) assigned to the volume-reduced cavity has little or no interfacial tension. Mold insert (120, 160) according to one of the preceding claims, characterized in that the volume of the reduced cavity associated surface of the mold insert (120, 160) is coated. Mold insert (120, 160) according to one of the preceding claims, characterized in that the volume of the reduced cavity associated surface of the mold insert (120. 160) is formed by a plastic. Mold insert (120, 160) according to one of the preceding claims, characterized in that the surface of the mold insert (120, 160) assigned to the volume-reduced cavity is formed by a polyolefin, in particular by polyethylene. Mold insert (120, 160) according to one of the preceding claims, characterized by a temperature-conducting element, in particular of metal. Mold insert (120, 160) according to one of the preceding claims, characterized in that a material thickness of the mold insert (120, 160) is between 0.8 mm and 8 mm, preferably approximately 2.5 mm. Mold insert (120, 160) according to one of the preceding claims, characterized in that the mold insert (120, 160) is manufactured as an injection-molded part. Mold insert (120, 160) according to one of the preceding claims, characterized in that joined-together part mold inserts form the mold insert (120, 160). Mold insert (120, 160) according to one of the preceding claims, characterized in that the mold insert (120, 160) can be removed after each molding operation. Mold part mold (110, 150) for a mold insert (120, 160) according to one of the preceding claims, characterized in that the mold part mold (110, 150) has a receptacle for at least one fastening element of the mold insert (120, 160). Apparatus for producing a molded part with a molded part mold (110, 150) having a cavity which imparts a shape to an introduced material, characterized in that a mold insert (120, 160) according to one of the FIGS Claims 1 to 17 in the molded part form (110, 150) can be arranged, so that when arranged mold insert (120. 160) a volume-reduced cavity is formed, which imprints an introduced material a volume-reduced form. Device after Claim 18 , characterized in that the volume-reduced cavity (111) forms a mold of the molded part to be produced, wherein the cavity formed by the molded part mold (110, 150) is enlarged by the material thicknesses of the mold insert (120, 160). Device according to one of Claims 18 or 19 , characterized in that the molded part form (110, 150) has an associated receptacle for the fastening element. Device according to one of Claims 14 to 20 , characterized in that the molded part form (110, 150) made of a metal, in particular stainless steel, steel, aluminum and / or magnesium, or a metal alloy is made. Device, according to one of Claims 18 to 21 , characterized in that the molded part form (110, 150) has an upper part and a lower part. Molded part, in particular foam molding, which with a device according to one of Claims 18 to 22 is made.

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