DE9407000U1 - Device for the co-vulcanization of thermoplastics and elastomers and composite profiles produced therewith - Google Patents

Description

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DIPLrING. HORST ROSE DlPLrlNGÄ.PETE.F? WOSEL.-.DIPLrlNG. PETER SOBISCH

PATENT ATTORNEYS AUTHORIZED BY THE EUROPEAN PATENT OFFICE - EUROPEAN PATENT ATTORNEYS

Patent Attorneys Rose, Kosel & Sobisch · Odastrasse 4a

Qdastrasse4a, D-37581 Bad Gandersheim D-37581 Bad Gandersheim

Germany

Telephone (05382)4038 Telex957422siedpd Fax (05382)4030

YourRef. OurRef. Date

2271/17 EN 15 July 1994

G βν-�Oδ 000, i
Meteor Gummiwerke KH Bädje GmbH & Co.

DESCRIPTION

Device for covulcanization of thermoplastics and elastomers

and composite profiles produced with them

The invention relates firstly to a device according to the preamble of claim 1.

In a known device of this type (EP 0 528 560 Al), a thermoplastic material on the one hand and an elastomer material on the other hand are fed into a multi-component injection head and extruded from it as a composite by coextrusion. This coextruded composite is immediately vulcanized and cooled. The plastic finally forms thin layers with a low coefficient of friction on those surface areas of a sealing profile that come into contact with a movable vehicle side window.

From EP 0 501 037 A2 it is known that the spray head

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Bank account: NORD/LB, NL Bad Gandersheim (bank code 250 599 Sdjf fcoj-Nrj22.-f1 8J373- Ifosfe Jokinto: Postgiroamt Hannover (bank code 25010O 30), account no. 66715-307

Oil from an elastomer extruder to feed a reactive urethane hot melt mixture. The result is the same, low-friction thin layers on the surface areas of a sealing profile that come into contact with the side window of the vehicle.

Another known device of the type mentioned above (DE 37 37 891 Al) uses certain types of rubber and thermoplastic molding compounds as elastomers. The two-stage extrusion process mentioned is used, which is time-consuming and labor-intensive.

DE 34 35 939 Cl shows, as is known per se, the use of two shear head extruders that feed into a common extrusion head when processing elastomers.

From DE-PS 2 059 496 a device for plasticizing plastics, in particular an injection molding machine, is known per se, in which two independently operating devices are provided for generating plasticizing heat. One of these devices is a shearing device that supplies shearing heat and is formed by a rotating mandrel.

From DE 31 18 429 A1 it is known per se to bond a cushioning strip made of foamed polyurethane or vinyl chloride via a pressure-sensitive, adhesive coating to a profile body made of thermoplastic material on the one hand and to a liner on the other hand.

From DE 38 35 211 Al it is known to produce a sealing strip from a U-shaped clamping strip made of

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Ol hard rubber, a complete covering of the clamping strip and with lips made of soft rubber and a sealing hose made of foam rubber from a common extrusion head. The composite profile then passes through a heating station and a hot air section that completes the vulcanization.

From DE 36 27 537 A1 (embodiment according to Fig. 1) it is known per se to extrude a U-shaped profile strand made of a PU-based adhesive mass with its central web onto an edge strip of a pivoting motor vehicle vent window (embodiment according to Fig. 3). The profile strand has an undercut insertion groove into which a complementary holding section of an insertion sealing profile can be pressed for form-fitting retention.

The invention is based on the object of expanding the field of application of the device mentioned at the beginning.

This object is achieved by the features of claim 1. In this way, the cost-effective and high-quality continuous production of composite profiles made of thermoplastics and elastomers is made possible. The device according to the invention is particularly suitable for the production of sealing profiles in which metal fastening rails have previously served as a holder for elastomer profile parts anchored to them. This latter construction is complex and relatively difficult to handle during assembly. The device according to the invention makes it possible to replace the metal fastening rails with profile parts made of plastics that are more suitable overall and to produce a composite profile made of plastics and elastomers at low cost.

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Oil stig in a combined extrusion process. This eliminates the need for subsequent anchoring of the elastomer profile parts with a metal fastening rail. According to the invention, plastic and elastomers are instead fastened to one another by chemical bonding during the joint extrusion. It is particularly advantageous to influence the operating parameters of each component of the composite profile. On the one hand, the plastic is calibrated and on the other hand, it is cooled down to the temperature for the subsequent joint extrusion with the elastomers from the multi-component extrusion head. For example, one to three different elastomer components can be used, e.g. foam or soft rubber in different hardnesses. These elastomer components are extruded into the multi-component extrusion head and extruded together with the at least one plastic component from the multi-component extrusion head. For the plastic, the processing or softening temperature is preferably 180 to 300 C. Crosslinking can be carried out in a conventional manner in a hot air or UHF system or in a salt bath or in a fluid bed.

The features of claim 2 allow an effective temperature control of the elastomer to achieve the optimum temperature level for all material components in the multi-component injection head.

The procedure according to claim 3 is used if the desired chemical bond cannot be achieved without an additional bonding layer made of composite material.

Claims 4 to 11 each characterize advantageous composite profiles produced according to the invention.

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Ol In principle, the invention is not only suitable for creating particularly inexpensive sealing profiles. In particular, it can be used for the automotive industry to inexpensively produce, for example, rain strips and water tank seals under the hood of vehicles. In these cases, the one component made of thermoplastic material takes over the function of the previous metal fastening rail.

Features and advantages of the invention are explained in more detail in the following description of embodiments of devices and composite profiles produced therewith according to the invention with reference to the drawings. It shows:

Fig. 1 is a plan view of a schematic representation of a first embodiment of the device,

Fig. 2 is a plan view of a part of a second embodiment of the device, enlarged compared to Fig. 1,

Fig. 3 is a plan view of a part of a third embodiment of the device, enlarged compared to Fig. 1 ,

Fig. 4 a cross-section through a first composite profile in assembled state,

Fig. 5 a cross-section through another composite profile in assembled state and

Fig. 6 a cross section through a third composite profile and

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Ol Fig. 7 a cross-section through a fourth composite profile.

Fig. 1 shows a device 1 for producing a chemical bond between thermoplastics on the one hand and elastomers on the other hand by covulcanization.

The device 1 has a plastic extruder 2, the outlet 3 of which is connected to an inlet 4 of a calibration and cooling section 5. An outlet 6 of the calibration and cooling section 5 is connected to an inlet 7 of a multi-component injection head 8.

The device 1 also has two elastomer extruders 9 and 10, whose outlets 11 and 12 are each connected to another inlet 13 and 14 of the multi-component injection head 8.

A composite profile consisting of plastic and elastomers is continuously extruded from an outlet 15 of the multi-component injection head 8, the components of which are chemically bonded to one another.

The composite profile moves in the direction of an arrow 16, first through a cross-linking section 17 and then through a cooling section 18, and then is fed by a conveyor 19 to a separation unit 20. In the separation unit 20, the endless composite profile is cut into the required sections.

In all drawings, identical parts are provided with identical reference numbers.

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Ol In the embodiment according to Fig. 2, the device 1 has, in addition to the elements according to Fig. 1, an inlet device 21 for a coupling material that promotes the chemical bond between the plastic and the elastomer (see e.g. 42 in Fig. 5 and 7). An outlet 22 of the inlet device 21 is connected to a further inlet 23 of the multi-component injection head 8. In this way, the coupling material can be introduced directly into the multi-component injection head 8 and fed between the plastic and elastomer surfaces to be combined. For reasons of space, the inlet device 21 can be arranged spatially above the extruders 2, 9, 10. An outlet channel 24 of the inlet device 21 then runs diagonally downwards to the inlet 23.

In the embodiment according to Fig. 3, the device 1 has a shearing head 25 and 26 at the outlets 11, 12 of the elastomer extruders 9, 10, the outlets 27 and 28 of which are each connected to the inlets 13, 14 of the multi-component injection head 8.

With the shear heads 25, 26 it is particularly effective to adjust the temperature of the elastomers to the desired level as they enter the multi-component injection head 8. In the embodiment according to Fig. 3, one or more feed devices corresponding to the feed device 21 according to Fig. 2 can also be used if required.

Fig. 4 shows a composite profile 29, which is composed of four profile strands 30 to 33. The profile strands 30, 32 consist of foam rubber, whereby the profile strand 30 is provided with a continuous cavity 34 in order to further improve its suspension properties.

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Ol The profile strand 31 is also provided with a continuous cavity 35 to achieve optimal suspension properties. The profile strand 31, like the profile strands 30, 32, consists of an elastomer. The following materials can be used as elastomers for the profile strands 30 to 32:

Foam rubber with a hardness of 10 to 30 Shore-α or soft rubber with a hardness of 30 to 70 Shore-α, both made from EPDM, SBR, CR, ECO, blends (mixtures) of EPDM with SBR with an EPDM weight proportion of 20 to 90%, blends of EPDM with SBR and/or polyoctenamer, or NBR.

The following thermoplastic elastomers (TPE) can also be used:

TPE based on styrene ethylene butylene styrene (S-EB-S),

TPE based on styrene butadiene styrene (SBS), TPE based on styrene isoprene styrene (SIS),

TPE based on elastomer alloys as TPO blends or TPO alloys, e.g. cross-linked EPDM/propylene blend (EPDM/PP) or

Ethylene vinyl acetate/vinylidene chloride (EVA/PVDC) or TPE based on thermoplastic polyurethanes (TPU); TPO is an abbreviation for thermoplastic polyolefin (elastomer)s.

The profile strands 30 to 32 are each formed by one of the previously described elastomer extruders and then vulcanized to one another along the contacting interfaces.

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There is a chemical bond of sufficient strength between the profile strands 30 to 32.

The profile strand 33, on the other hand, consists of a thermoplastic material. The following materials, for example, can be used:

PPE polyphenylene ether,

PP polypropylene,

PE (LDPE, low density PE),

PE (HDPE, high density PE),
piss polyisobutylene,

PS polystyrene,

PA polyamide,

PC polycarbonate,

PETP Polyethylene terephthalate,
POM polyoxymethylene,
Epoxy resins,
Phenolformaldehyde resins,

PES Polyester,

PPO polyphenyl ether or
PVC Polyvinyl chloride.

These plastics can be used with or without reinforcement, e.g. with carbon or glass fibers.

The profile strand 33 was produced by one of the previously described plastic extruders 2 with a subsequent calibration and cooling section 5 and was co-extruded with the profile strands 30 to 32 in the previously described multi-component injection head 8. The subsequent co-vulcanization also created a sufficiently strong chemical bond between the profile strands and 33.

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The composite profile 29 obtained in this way is held on the one hand by an anchoring groove 36 on a folded edge 37 of a motor vehicle body 38 and on the other hand is fastened to a body panel 40 with a self-tapping screw 39 penetrating the profile strand 33. This results in a stable connection of the composite profile 29 to the body 38 using the simplest of means. The composite profile 29 serves, for example, as a sealing profile for the side parts of the roof frame of a folding top or hardtop for a convertible or even for a coupe.

Fig. 5 shows a composite profile 41 that is essentially constructed and designed in the same way as the composite profile 29 according to Fig. 4. The connection to the motor vehicle body 38 is also made in the same way as in Fig. 4. The difference compared to Fig. 4 is that a layer of a coupling material 42 is arranged between the profile strands 31 and 32. The coupling material 42 has the task of improving the chemical bond between the elastomer of the profile strand 31 and the thermoplastic of the profile strand 33. The following materials, for example, can be considered as coupling material 42:

EPDM in blends with PP, PE, PS, PIB, PES, as well as other polymers from the above-mentioned list of materials of profile strand 33 in weight proportions < 20%,

Blends EPDM - CR - SBR - Polyoctenamer or EPDM compounds with resin additives (e.g. epoxy resins).

If the profile strand 33 consists of a TPE, a polypropylene primer, for example, can be considered as the coupling material 42.

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Ol Fig. 6 shows another composite profile 43, in which the profile strand 30 consists of foam rubber and almost completely surrounds the composite profile 43. The profile strand 31 is arranged inside the profile strand 30, which also consists of an elastomer and has a chemical bond with the profile strand 30 at the separating surfaces. Continuous cavities 44 and 45 are formed between the profile strands 30 and 31 to improve the elastic properties of the composite profile 43.

The profile strand 33 has a substantially T-shaped cross-sectional area in Fig. 6 and is partially embedded in the profile strands 30, 31, whereby here too there is a sufficiently strong chemical bond at the interfaces due to the aforementioned coextrusion and covulcanization.

At its lower free end, the composite profile 43 in Fig. 6 has assembly openings 46 arranged at a distance from one another in the longitudinal direction, through which a fastening element can be guided and connected to a body part (not shown). A lip 48 of the profile strip 30 made of foam rubber covers the assembly openings 46. The composite profile 43 serves, for example, as a sealing profile for the front cross section of the roof frame of a folding top or hardtop for a convertible or even for a coupe.

Fig. 7 shows yet another composite profile 47, which is particularly suitable as a sealing profile for the front cross section and the side parts of the roof frame of a folding top or hardtop for a convertible or also for a coupe.

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Ol The composite profile 47 has the profile strand 33 made of a thermoplastic material, which is essentially U-shaped in cross-section. The profile strand 33 is provided with several assembly openings 46 arranged at a distance from one another in the longitudinal direction, each of which is designed with all-round play for a sheet metal screw 39. During assembly, the composite profile 47 can thus be moved within limits in the longitudinal and transverse directions relative to the sheet metal screws 39 until the optimal position of the composite profile 47 is reached. The sheet metal screws 39 are then tightened.

One longitudinal end of the profile strand 33 is formed as a first coupling element 49. A cover profile strand 50 is vulcanized onto the profile strand 33 on its longitudinal side opposite the first coupling element 49. The cover profile strand 50 has an additional profile strand 51 made of foam rubber, which is vulcanized onto a base 52 and a leg 53 of the profile strand 33 via the coupling material 42. The cover profile strand 50 also includes a further profile strand 54 made of soft rubber that covers the profile strand 33 and is vulcanized onto the additional profile strand 51 with one long end and onto a coupling profile strand 55 with its other long end. The coupling profile strand 55 consists of a thermoplastic material and has a second coupling element that forms a snap closure 56 with the first coupling element 49.

57 on.

On the side of the profile strand 33 opposite the additional profile strand 51, a sealing profile strand

58 made of foam rubber vulcanized over the coupling material 42 .

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Ol In Fig. 7, the body panel 40 to which the composite profile 47 is to be mounted is indicated in dash-dotted lines at the top. The serrated parts of the profile strands 51, 58 are pressed against the body panel 40 to form a seal and are deformed accordingly. Until the sheet metal screws 39 are tightened as mentioned above, the snap fastener 56 is released and the further profile strand 54 is folded downwards out of the way of the screwdriver. After the sheet metal screws 39 are tightened, the further profile strand 54 with the coupling profile strand 55 is folded upwards and the snap fastener 56 is closed. This creates a cavity 59 into which a window 60 of the motor vehicle can deform the further profile strand 54 when the top is put on, as is indicated in dash-dotted lines in Fig. 7.

In Fig. 7, the largest part of the outer surface of the additional profile strand 51 and the further profile strand 54 is covered with an exaggeratedly thick but in reality extremely thin sliding layer 61. The sliding layer 61 reduces the sliding friction between the further profile strand 54 and the disk 60.

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Claims (11)

DIPL-ING. HORST ROSE DIPL-ING. PETER KOSEL: DIPLv-&Iacgr;&Ngr;&OHacgr;. PEtEf? SOBISCH PATENT ATTORNEYS AUTHORIZED BY THE EUROPEAN PATENT OFFICE - EUROPEAN PATENT ATTORNEYS Patent Attorneys Rose, Kosel & Sobisch · Odastrasse 4a Odastrasse 4a, D-37581 Bad Gandersheim D-37581 Bad Gandersheim Germany Telephone (05382)4038 Telex957422siedpd Fax (05382)4030 YourRef. OurRef. Date 2271/17 EN 26 April 1994 Meteor Gummiwerke K.H. Bädje GmbH & Co. PROTECTION CLAIMS 1. Device (1) for producing a chemical bond between thermoplastics on the one hand and elastomers on the other hand by covulcanization, characterized in that a calibration and cooling section (5) is inserted between an outlet (3) of at least one plastic extruder (2) and an inlet (7) of a multi-component injection head (8), that an outlet (11; 12) of at least one elastomer extruder (9; 10) is connected to an inlet (13; 14) of the multi-component injection head (8), and that a cross-linking section (17) is connected to an outlet (15) of the multi-component injection head (8) for a composite profile (29; 41; 43; 47) made of thermoplastic plastic and elastomer, and a cooling section (18) is connected to the cross-linking section (17). -2-PK/La Bank account: NORD/LB, NL Bad Gandersheim (bank code 250 5OQÖ0), account no. *i»li.'22S 18 S70* Bank account: Postgiroamt Hannover (bank code 250100 30), account no. 66715-307 —2— Oil 2. Device according to claim 1, characterized in that at least one of the elastomer extruders is designed as a shear head extruder (9,25;10,26). 3. Device according to claim 1 or 2, characterized in that at least one feed device (21) for a coupling material promoting the chemical bond between the plastic and the elastomer (42) is connected to an inlet (23) of the multi-component injection head (8), 4. Composite profile (29) manufactured with the device according to one of claims 1 to 3, characterized in that a profile strand (33) made of a thermoplastic material can be fixed to a body sheet (40), and that an elastomer profile strand (31) made of soft rubber is vulcanized onto the plastic profile strand (33). 5. Composite profile according to claim 4, characterized in that at least one additional elastomer profile strand (30; 32) made of foam rubber is vulcanized onto the elastomer profile strand (31) made of soft rubber, and that an additional elastomer profile strand (30) made of foam rubber can be coupled (at 36) to a body region (at 37). 6. Composite profile (43) manufactured with the device according to one of claims 1 to 3, characterized in that a profile strand (33) made of a thermoplastic material is essentially T-shaped, -3- -3- Ol that an elastomer profile strand (31) made of soft rubber is vulcanized onto a first part of the circumference of the plastic profile strand (33), and that an additional elastomer profile strand (30) made of foam rubber is vulcanized onto a second part of the circumference of the plastic profile strand (33) and onto the elastomer profile strand (31). 7. Composite profile according to claim 6, characterized in that the additional elastomer profile strand (30) essentially surrounds the entire remaining composite profile (43) and extends with a lip (48) over assembly openings (46) for receiving fastening elements which are located in the plastic profile strand (33) and in another end of the additional elastomer profile strand (30). 8. Composite profile (47) manufactured with the device according to one of claims 1 to 3, characterized in that a profile strand (33) made of a thermoplastic material is essentially U-shaped and has mounting openings (46) in its base (52) for receiving fastening elements (at 39), that a longitudinal end of the plastic profile strand (33) is shaped as a first coupling element (49), that a cover profile strand (50) is vulcanized onto the plastic profile strand (33) on its longitudinal side opposite the first coupling element (49), and that a free longitudinal end of the cover profile strand -4- -4- Oil (50) is provided with a second coupling element (57) forming a snap closure (56) with the first coupling element (49). 9. Composite profile according to claim 8, characterized in that the cover profile strand (50) has an elastomer profile strand (54) made of soft rubber covering the plastic profile strand (33). 10. Composite profile according to claim 9, characterized in that a longitudinal end of the elastomer profile strand (54) is vulcanized to an additional elastomer profile strand (51) made of foam rubber, which in turn is vulcanized to the plastic profile strand (33). 11. Composite profile according to one of claims 8 to 10,
characterized in that the second coupling element (57) is formed in a coupling profile strand (55) made of made of a thermoplastic material, and that the coupling profile strand (55) is connected to the
remaining cover profile strand (50) consisting of elastomers is vulcanized.