DE19853212A1 - EPS foam molding contains embedded fittings offering e.g. points of attachment for built-in furniture door, with improved mechanical- and handling properties - Google Patents

Abstract

Embedded components (7) are molded-into the interior of the foam plastic. The inner body (6) includes points of external attachment (9).

Description

The present invention relates to a molded part made of EPS Foam plastic. Expandable polystyrenes, usually be called EPS, and both made of pure polystyrene (PS) as well as styrene copolymers or polystyrene Copolymers, such as. B. styrene / acrylonitrile Copolymers can exist because of their low Dense, good processability by sawing or cutting, good heat and sound insulation in various areas technology more and more application. Hard as well as soft EPS Foam plastics are used as packaging material, in construction, as upholstery material, for refrigerator insulation and as coverings used.  

EPS is stored by foaming from intermediate pre-expanded beads to any shape with the help of Automatic molding foam machine.

Molded parts made of EPS particle foam, with usual densities of 20-50 kg / m ³ , are in any case much lighter than conventional parts with the same dimensions made of wood, metal or non-foamed plastic. If it is not a very simple shape, such as rectangular blocks or flat plates, molded parts are usually easier to produce than parts with similar dimensions made of wood, which have to be machined by relatively complex operations. It would therefore be desirable in many cases where weight or simplification of production play a major role to replace conventional components made of wood, metal or non-foamed plastic with molded parts made of EPS particle foam.

Molded parts made of EPS particle foam are used in the generally used only under conditions where they only withstand widely distributed pressure forces, and not torsional, shear, or localized Pulling forces, against which the material is generally one has poor resilience.

Molded parts made of EPS particle foam are used, for. B. as a wall or ceiling cladding elements used. You will remember  Glued wall surface because it is hardly possible to pass it through a other fasteners such. B. with nails or screws to attach to a wall or scaffold without the Area in the EPS mass around the screw or nail torn or crumbled under mechanical stress.

Transport containers made of EPS particle foam are made by a tongue and groove fastening that extends over the whole Edge area between the lid and container extends through Squeeze closed because of a locally engaging Closure means such as B. a buckle or hook, would soon lead to material wear.

It is already known to form so-called integral foam parts made of polystyrene using the "thermoplastic foam casting" technique (TSG). These parts are characterized by a porous core and an almost massive edge zone. They are used in the furniture industry for specifically shaped furniture parts and as housings for TV sets and the like. However, the density of these parts is still relatively high, between 500 kg / m ³ and 800 kg / m ³ depending on the processing method. As a result, the weight saving compared to conventional wood (densities at 600 kg / m ³ -800 kg / m ³ ) or hard wood fiber boards (density at 1000 kg / m ³ ) is low and the quantity of relatively expensive plastic is high.

It is therefore the object of the invention to produce a molded part made of EPS Foam plastic to create the mechanical stress and handling or interaction requirements with other objects or components or substrates better does justice to the conventionally foamed EPS Foam plastic moldings, and which has lower densities and uses less plastic than that Integral foam parts.

A molded part made of EPS foam plastic solves this task the features of claim 1. Preferred Embodiments and developments of the invention The molded part results from the subclaims.

The outer shape of the molded part is foamed Foam plastic mass determined. The molding has a Insert part, one inside the foam plastic foamed inner body and at least one from the outside has tangible connecting part. Preferably that is Provide connecting part with fasteners for this are provided, the molding via conjugate Fasten another object with this Connect object.

The connecting part of the insert can already be used in the production of the molded part according to the invention:
It can namely be gripped with appropriate tools in order to be held in the mold in which the molded part according to the invention is foamed so that on the one hand the inner body of the insert can be foamed in from all sides and on the other hand the fastening means for the later intended use of the molded part are positioned. Since the holding tools, e.g. B. plug or threaded rods protrude from the molded part during foaming, the connecting part, even if it is located inside the molded part, is accessible or graspable from the outside after foaming without having to remove foam plastic beforehand.

The inner body of the insert is through the Foaming process foamed in the foam plastic mass and thus firmly connected to it, so that the connecting part with its fasteners with the foam plastic mass connected is. If the connector is firmly attached to the inner body, so it is also firmly connected to the foam plastic mass. The connection made with the material contact Foam plastic mass thus extends over one larger area than if only a few Connection part, such as. B. a threaded sleeve in a hole the foam plastic mass would have been inserted. So that's it Molding according to the invention is able to a higher Total load, which is over the fasteners initiated and distributed over the inner body, without breaking  in foam plastic or without tearing out the connecting part, to resist.

The bulk density of the pre-expanded EPS essentially determines the density of the expanded EPS particle foam plastic. The density in turn has a decisive influence on its mechanical properties. Greater resistance to drawing, bending or shear forces both in the connection zone between the insert and the foam plastic and also the foam plastic part as a whole is obtained by a higher density. Depending on the foreseeable mechanical loads on the molded part, the bulk density can be between 20 kg / m ³ and 200 kg / m ³ .

By choosing the type of EPS used, the mechanical Properties of the molded part can be optimized. It is suitable preferably polyphenyl ether / polystyrene (PPE / PS) and modified PPE / PS copolymers.

The molded part according to the invention can thus not only firmly be connected to an object, e.g. B. on a scaffold a foamed threaded bushing, bayonet connection or the like are attached. It can also be used with moving Fasteners of an object, e.g. B. on a scaffold articulated hinges, with which a movable Connection with the other object, e.g. B. a swivel  Connection with the scaffold. thanks to the Distribution of forces caused by the foamed inner body the molded part can respond to the reaction forces at the relative Movement of the molded part relative to the object occur, without breaking the foam plastic or tearing the Resist connection part.

Further details and advantages of the inventive Shaped parts can be found in the following description and explained by embodiments that to the attached Refer to drawing.

Show it:

Figure 1 is a partial view of a molded part formed as a built-in kitchen cabinet door in section along the plane II-II of Fig. 2.

Figure 2 is a section of the same molding along the plane II of Fig. 1.

Fig. 3 is a partial schematic representation of a horizontal plate formed as a shelf molded in section along the plane IV-IV of Fig. 4;

Fig. 4 is a section along the plane III-III of Fig. 3;

Fig. 5 is a schematic representation of another embodiment.

Figs. 1 and 2 show a molded part which has the general form of a plate 1. The plate 1 made of EPS particle foam is designed as a cabinet door for a built-in kitchen cabinet. On the side provided as the outside of the cabinet door, the plate 1 has an area 2 projecting relative to the plate surface 3 of the edge area of the plate 1 . In the middle of the plate 1 , the outside again has an area 11 which recesses relative to the area 2 . This results in paragraphs 4 and 12 . The affordably projecting, profiled area 2 not only has a decorative effect, but also generally contributes to the torsional stability of the entire plate 1 . On the opposite side of the plate 1 , which is provided as the inside of the cabinet door, in the vicinity of one edge 13 of the plate 1 , there are two or more recessed areas, which act as recesses 5 for receiving hinge parts, which are on the side walls of the kitchen cabinet are attached, are provided. Near the edge 13 , next to the recesses 5 of the plate 1 , two or more separate inserts 7 are foamed into the foam plastic. The inserts 7 each consist of a sheet metal plate 6 , which is completely foamed in the foam plastic and thus forms an inner body. The sheet metal plate 6 can preferably be about 5 cm to about 15 cm long, about 3 cm to about 10 cm wide and about 0.5 cm to about 1.5 mm thick. In Fig. 1 it is shown flat, rectangular, with a cutout around the recess 5 . However, it can also have angled edges and / or other shapes. The plate 6 is perforated in several places. The perforations 8 can be round (diameter about 0.5 cm to about 2 cm) or other shapes. The surfaces of the perforations 8 allow direct contact of the foam plastic masses or particles which are located on either side of the sheet metal plate 6 , so that the sheet metal plate 6 is not only embedded in the foam plastic but firmly anchored. The sheet metal plate 6 carries two threaded bushings 9 , 10 perpendicular to it. The threaded bushings 9 , 10 serve to fasten a hinge part (not shown) which, on the other hand, is fastened to the inner side wall of the kitchen cabinet. In the embodiment shown in FIGS. 1 and 2, the threaded bushings 9 , 10 are shorter than the thickness of the plate 1 . When foaming the molded part, the sheet metal plate 6 is expediently brought to the correct position in the automatic foaming machine with the aid of the threaded bushings 9 , 10 and with the aid of threaded rods and held there. The sheet metal plate 6 is positioned in such a way that it is sufficiently surrounded by foam plastic on all sides. You can e.g. B. be positioned at approximately half the thickness of the plate 1 . At least a second position of the plate 1 and in the same arrangement opposite the plate edge 13 and a recess, there is a second (not shown) identically designed insert which is connected to a second hinge part of the kitchen cabinet, so that the plate 1 in the case of Kitchen built-in furniture is mounted in the usual way as a cabinet door. At another, also not shown point of the plate 1 there is another insert with a perforated plate and with a connecting part, the fastening means of which can be gripped from the outer side of the cabinet door, so that a handle can be mounted thereon. In a similar way, a door lock could also be foamed into the plate 1 , in such a way that the bolt is embedded flush on the side edge.

In the assembled state, the foamed component, namely the plate 1 , ie the foam plastic mass itself, assumes a load-bearing or mechanical function. If the door is not operated, the molded part is only loaded by its low static weight. When the door is actuated, the foam plastic mass transfers reaction forces from the actuated handle to the hinges, which can be very variable depending on the mode of actuation. In order to withstand even rough operations with tensile or torsional effects, an EPS particle foam is preferably selected from the polystyrene rigid foams foamed with a relatively high density or bulk density.

Polyphenyl ether / polystyrene (PPE / PS) and modified PPE / PS copolymers are suitable. They have good, albeit depending on the bulk density, resistance to pressure, drawing, bending and shear forces. For normal loads, the bulk density can be 50-80 kg / m ³ , so that a weight gain of approximately a factor of 10 over wood is achieved.

There are z. B. the EPS particle foams, which under of the CARIL brand manufactured by Shell Chemical be like the Caril Series 3. These products are at higher pressures and temperatures than conventional EPS Foams foamed, and are also more thermostable than this.

Both the outer and the inner surface of the door and generally the surfaces of the inventive Foam plastic molded part can have a finishing, e.g. B. by coating with a film, by painting, by Veneer, by sanding or laminating. A coating with a film not only contributes to an aesthetic effect, but can also protect against hot bodies or flames serve. The foam plastic expediently also contains flame retardant in its mass.

According to the invention described above can be special advantageous curved parts for corner cabinets with a  curved shape, in particular a cylindrical surface are manufactured. Round wooden doors are particularly expensive to manufacture. On the other hand, it is not expensive to buy one To produce a mold for a curved plate. This costs about the same as making one Forming tool for a flat plate.

In the same respect it should be noted that at Wooden cabinet doors trim strips are made separately and in a separate operation on the base wood panel need to be attached. For the molded parts according to the The present invention only needs the mold to be designed accordingly, in the same operation to manufacture the plate together with the decorative strips.

In FIGS. 3 and 4 shows a detail, namely a corner, of a molded part is shown, which is designed as a shelf and insert plate. The plate 101 made of foam plastic is shown rectangular. However, the plate 101 can also be generally polygonal, round or oval. The upper surface 103 can have a shoulder 104 and a thickened projecting edge part 102 . A cutout 105 in the plate 101 to allow electrical cables or the like to pass through is also conceivable. The foam plastic mass comprises an insert 107 with a frame-shaped inner body 106 , the dimensions of which essentially correspond to the mass per unit area of the plate 101 , ie the dimensions are shortened by at least so much that the inner body 106 is completely embedded in the foam plastic. The frame-shaped inner body 106 can be formed either from iron or aluminum or from a hard plastic. Angle or other profiled sheets can be used for stiffening. Over the entire circumference, this frame-shaped inner body 106 has perforations 108 through which the plastic mass can penetrate when foaming, so that the plastic masses weld to one another on both sides of the frame. The inner body 106 carries two threaded bushes 109 , 110 at each corner of the frame. As can be seen from FIG. 4, the threaded bushing 110 extends to the lower surface of the plastic plate 101 and the threaded bushing 109 extends to the upper surface of the plastic plate. The threaded bushes 109 , 110 could also protrude from the surface of the molded part, e.g. B. to extend the thread. The threaded bushing 110 enables a connection by means of a threaded rod to a shelf or display case surface located further down or to the floor. The threaded bush 109 also allows a connection to a higher component by means of a threaded rod. The threaded bushes 109 , 110 could also be designed as plug connections. In the illustrated embodiment, both the insert 107 in the edge zone and the foam plastic in the middle take on the supporting function for the objects placed on the shelf. If a particularly heavy load on the shelf is provided, it is also possible to foam into the molded part instead of a frame of a perforated, resistant plate, the surface of which corresponds essentially to the mass of the foam plate, i.e. the dimensions of the resistant plate are compared to the dimensions of the Foam plastic sheet shortened by so much that it is completely foamed. Both an iron sheet and an aluminum plate as well as a hard plastic plate can be used, each of which is designed as a perforated plate with the aid of perforations distributed over the entire surface. In this training, the insert essentially takes on the supporting function. An iron sheet has a relatively high density, but since a sheet with a thickness of about 1 mm is generally sufficient, a considerable weight gain compared to a wood or Wood fiber board of the same thickness achieved. Instead of a perforated, but rather solid sheet metal plate, a lattice-like framework of round or profile bars can also be used.

Fig. 5 shows schematically shown a further embodiment in the form of a partition wall element. The foam part 201 is indicated schematically by its edge 203 . The insert 207 includes, similar to the previous exemplary embodiments, a perforated plate 206 with perforations 208 which is foamed into the mass of the foam part 201 . To improve the anchoring, the perforated plate can have wings 204 , 205 bent at an angle, in particular at right angles to its plane. A hook 209 protrudes from the edge 203 , which makes it possible to hang the molded part on rods or other supports equipped with slots. This molding proves to be particularly suitable as a very inexpensive component of a modular system for setting up trade fair stands or office space subdivisions.

The exemplary embodiments described above illustrate that the molded parts according to the invention in various areas of application such as trade fair construction (wall elements, Showcase floors), shopfitting (counter components, panels), Interior fittings (cabinet doors, shelf components), Camping equipment, caravan interiors (Lining parts and furniture) or office equipment (Partitions) can be used.

If the molded part is plate-shaped and the inner body of the insert is an approximately 1 mm thick iron sheet, the surface of which has approximately the surface of the foam plastic plate, then a weight gain factor of approximately 2 is achieved with the molded parts according to the invention compared to wood fiber plates with plates of approximately 20 mm. With inserts of small dimensions, as shown in FIGS. 1 or 5, a weight gain factor of up to 8 can be achieved. In special cases, with low mechanical requirements, the bulk density of the EPS or other foams can be reduced, so that an even greater weight gain factor is achieved.

The corresponding design of the mold allows Realization of flat, structured and freely shaped Surfaces and components in lightweight construction with simultaneous Compliance with static and mechanical requirements through foamed inserts. The molded parts according to the invention replace wooden parts, the surfaces of which are usually only returning through material removal or projecting through Composite of several components can be formed, and their Forming into curved or curved parts is very complex.

Claims (31)

1. molded part made of EPS foam plastic, characterized by at least one insert ( 7 , 107 , 207 ) which has an inner body ( 6 , 106 , 206 ) foamed in the interior of the foam plastic and at least one connecting part ( 9 , 10 , 109) 110 , 209 ). 2. Molding according to claim 1, wherein said Connection part is provided with fasteners are intended to conjugate the molded part Fastening another object with the to connect the named object. 3. Molding according to claim 1 or 2, characterized in that the connection between the molded part and the The object is a fixed connection. 4. Molding according to claim 1 or 2, characterized in that the connection between the molded part and the Subject a movable connection, in particular a Hinge connection is. 5. Molding according to one of claims 1-4, characterized characterized that the EPS between pure polystyrene and polystyrene copolymers is selected.   6. Molding according to one of claims 1-5, characterized characterized that the EPS between the Polyphenyl ether / polystyrene and modified Polyphenyl ether / polystyrene copolymers is selected. 7. Molded parts according to one of claims 1-6, characterized in that the EPS has a bulk density of 20-200 kg / m ³ . 8. Molding according to one of claims 1 to 7, characterized in that the EPS has a bulk density of 50-80 kg / m ³ . 9. Molding according to one of claims 1 to 8, characterized characterized that the foam plastic Contains flame retardants. 10. Shaped part according to one of claims 1 to 9, characterized in that the surface ( 2 , 3 , 4 , 11 , 13 , 102 , 103 , 104 , 203 ) of the foam plastic is refined, in particular by coating with a film, painting, Veneer, sanding or laminating. 11. Molding according to one of the preceding claims, characterized in that the insert part ( 7 , 107 , 207 ) is formed from metal and / or plastic parts. 12. Shaped part according to one of the preceding claims, characterized in that said inner body ( 6 , 106 , 206 ) has perforations ( 8 , 108 , 208 ) or at least one perforated plate. 13. Molding according to one of claims 11 or 12, characterized characterized in that said inner body Hard plastic is molded. 14. Molding according to one of claims 11 or 12, characterized in that said inner body has a sheet metal plate ( 6 ). 15. Molding according to one of the preceding claims, characterized in that the foam plastic is essentially in the form of a plate ( 1 , 101 , 201 ). 16. Molding according to claim 15, characterized in that said plate ( 1 , 101 , 201 ) is rectangular, polygonal, round or oval. 17. Molding according to claim 15 or 16, characterized characterized that the said plate is curved, is curved in particular according to a cylindrical surface. 18. Shaped part according to one of claims 15 to 17, characterized in that said plate ( 1 , 101 ) has projecting areas ( 2 , 102 ) opposite the plate surface. 19. Shaped part according to one of claims 15 to 18, characterized in that said plate ( 1 ) has recessed areas ( 11 , 5 ) opposite the plate surface. 20. Molding according to one of claims 15 to 19, characterized characterized in that the molding as a door, in particular is designed as a cabinet door for furniture. 21. Molding according to claim 20, characterized in that said plate ( 1 ) is formed from foam plastic with recesses ( 5 ) for receiving hinge parts on one side. 22. Shaped part according to one of claims 15 to 19, characterized in that the shaped part is designed as a shelf part ( 101 ) or showcase part. 23. Molding according to one of claims 15 to 19, characterized in that the molding is designed as a wall element ( 201 ). 24. Molding according to one of the preceding claims, characterized characterized in that the molded part as a lining part is trained. 25. Shaped part according to one of claims 15 to 24, characterized in that the foam plastic comprises an inner body in the form of a sheet, the surface of which essentially corresponds to the mass per unit area of said plate ( 101 ) made of foam plastic. 26. Shaped part according to one of claims 15 to 24, characterized in that the foam plastic comprises a frame-shaped inner body ( 106 ), the dimensions of which essentially correspond to the mass per unit area of the said plate ( 101 ) made of foam plastic. 27. Molding according to one of claims 15 to 24, characterized in that the foam plastic comprises a plurality of separate inserts ( 7 ). 28. Shaped part according to one of the preceding claims, characterized in that said connecting part ( 109 , 110 ) extends at least up to a surface of the shaped part. 29. Molding according to claim 28, characterized in that the connecting part protrudes from the molded part.   30. Molding according to one of the preceding claims, characterized in that the fastening means of the connecting part are selected from the groups consisting of plug-in connection means, threaded connection means ( 9 , 10 , 109 , 110 ) and hooking means ( 209 ). 31. Molding according to claim 30, characterized in that the said fastening means of the connecting part are threads of threaded bushings ( 9 , 10 , 109 , 110 ).