DE3122149A1 - Process for joining thermoplastic materials and metals - Google Patents

Abstract

The invention relates to a process for joining thermoplastic materials and metals by means of a self-hardening adhesive, the adhesion taking place not only via an end abutment, but at the same time by means of a two-sided overlapping of the thermoplastic part around the metal counterpart. Preferably the groove is delimited by hook-shaped or U-shaped legs whose inner leg surfaces are inclined towards one another, so that a groove which tapers towards the groove opening is formed. In one embodiment, sealing elements are present on the inner wall parts of the hook-shaped legs which enclose the groove, which sealing elements are embedded in the adhesive on adhesive bonding. The groove or groove opening of the thermoplastic part contains sealing elements and/or forms them itself by means of one or more groove constrictions in the vicinity of the groove opening or between the groove centre and groove opening. The space formed by the groove base, sealing element and inner wall parts of the hook-shaped or U-shaped legs serves as a receptacle for an adhesive or an adhesive component.

Description

Process for joining plastomer materials

and metals The present invention relates to a method for Joining of plastomeric materials and metals by means of a solidifying Adhesive, preferably a thermoset adhesive. The gluing does not take place only through a front edge joint, but at the same time through a two-sided overlap of the plastomer part around the metallic partner. Due to the special design of the groove or the use of sealing elements supports the strength of the connection.

There are already a wide variety of adhesives and processes for Bonding objects, in particular metals, using thermosets or thermosetting adhesives or plastomeric adhesives known (cf.

DE-PS 950 588, DE-PS 943 182 and DE-PS 885 902).

Especially with the different materials, plastic and Metal problems arise, for example, if the materials are not flat, but at their edges (forehead edge joints) must be glued and if it is when gluing is about extensive or larger, heavily used parts, which at their edge resp.

must be connected by an adhesive over a front edge joint.

The aim and object of the present invention was therefore to provide a method For joining plastomeric materials, especially plastic parts and metal parts where the gluing is carried out at least partially over the front edge joints got to. In the case of the material parts to be glued in this way, compared to one known per se Adhesion to the edge parts an increased connection strength can be achieved. Furthermore, it should be achieved that in addition to an improved adhesive bond Assembly of the work parts can be made easier in terms of the amount of work involved. Since that Gluing the material parts and applying the adhesive is time-consuming and leads to difficulties in handling when gluing (leakage or flow the adhesive, unclean glued areas, damage to work parts or machines), an improvement should also be achieved here.

According to the invention it has been found that a better connection then results of plastomeric materials, plastic parts, plastic plates and the like with metal parts, Sheet metal etc. results, if the bond is not only via a front edge joint, but at the same time by a two-sided overlap of the plastomer part around the metallic partner takes place.

This increases the strength of the connection compared to normal gluing reached or increased, the plastomeric material part is shaped in such a way that that on the part to be connected to the metal, the groove or groove opening of the plastomer Material part contains a sealing element or it forms. The groove is used as a depot used or formed for the adhesive or for an adhesive component.

According to a preferred embodiment, the groove is clipped or limited u-shaped legs, the inner leg surfaces are inclined towards each other, so that a groove tapered towards the groove opening (viewed in the unattached state) is formed. The tapered groove is bent up or down when the metal part is inserted. is widened, whereby an additional force effect and thus for gluing increased connection strength results.

According to another embodiment, the tapered groove on insertion of the metal part not or only slightly expanded, so that in the Nuthohlraum forms an adhesive wedge which, after hardening, leads to increased bond strength leads, According to a preferred embodiment, contain the groove or the inner wall parts of the clamp-like or U-shaped legs have grooves or webs, in which the adhesive is poured or embedded for bonding. By this training causes an increased connection strength.

According to a preferred embodiment are on the inner wall parts the clamp-like or U-shaped legs that enclose the groove, sealing elements present, which are embedded in the adhesive during gluing. The one to be connected The plastomer part has a groove that is separated from the inner wall parts of the two or U-shaped leg is limited to, the opening width of the groove bottom greater than or approximately equal to the cross-sectional thickness of the outer to be inserted than Spring formed edge part of the metal material is. The groove or groove opening of the plastomeric material part contains sealing elements and / or forms these itself by one or more groove constrictions (cross-sectional constriction of the groove) in the vicinity the slot opening or between the center of the slot and the slot opening. The from groove base, sealing element and inner wall parts of the clamp or U-shaped leg formed space serves as Depot for an adhesive or an adhesive component. Through this embodiment succeeds in using the adhesive or in the case of thermosets or thermosets, which consist of two thermoset components, an adhesive component of the thermoset, to be brought into the depot room before disposal and, if necessary, to be kept until assembly.

According to a preferred similar embodiment, the to be connected Plastomer part has a groove bounded by two clamp-shaped or U-shaped legs is on, the spring end of the metal part in terms of its cross section diameter on the outer spring edge part is not thicker than the opening width of the Groove base. The adhesive or, in the case of a thermoset or thermoset adhesive, a Adhesive component is brought into the depot before assembly, which is carried out by Groove base, inner wall surface parts, the clamp or groove delimiting the groove

U-shaped leg and one or more between the groove center or Groove opening and / or sealing elements located on the groove opening are limited and / or is formed, which has a channel-like, in cross-section circular, wedge or

Has triangular, elliptical, rectangular or parabolic shape.

The sealing elements are preferably made of the same plastomer Material like that to be connected to the metal part plastomers Material part (plastic part). They run depending on the outer edge shape and training approximately parallel or at an angle or with the outer edge of the clamp or u-shaped leg.

According to another preferred embodiment, at least one is Sealing element designed as a sealing sleeve, which, starting from the edges of the two clamps or U-shaped legs or from the inner wall parts of the bracket-shaped or U-shaped Leg, the groove opening or one between the middle part of the groove and the groove opening lying groove space along the plastomeric material part to be connected thin-walled encloses. When joining, the thin-walled sealing sleeve is removed from the metal spring separated and is preferably placed on the metal surface inclined to the groove base. The edge part of the spring can be heated briefly before joining, see above that a fusion bonding process can take place to a certain extent.

According to another preferred embodiment, the sealing element by overlapping or abutting one of the slot openings and / or from an inner wall surface of each of the clamp-shaped or U-shaped legs outgoing sealing lips or by formation two or more mutually extending sealing lips, which through a slot with a small Opening width separated in the middle or approximately in the middle, formed.

In this embodiment, the sealing element is admittedly by several Sealing lips are formed that do not form a complete seal like a sealing envelope at the groove opening within the groove opening. The formation of the sealing lip however, is done in such a way that by overlapping or abutting or colliding with each other the sealing lips, the adhesive remains in the depot space and even with Edges do not or hardly run downwards.

The points at which the channel-like groove with sealing elements ends, is preferred laterally through adhesive strips, material moldings or material formation limited, so that sideways running can also be prevented.

After a further training, the inner wall parts of the clamp- or U-shaped legs are provided with grooves that form the positive connection support. The grooves should be parallel, depending on the shape and formation of the edge or at an angle to the outer edge of the bracket-shaped leg get lost.

According to a preferred embodiment, the grooves have different ones Depths and different distances from one another.

According to another embodiment, the groove depths take the groove opening towards.

The one with the clamp or U-shaped legs on at least one The edge part provided with a plastomeric material part can be made from the known plastics exist (e.g. amorphous partially crystalline or crystalline thermoplastics or also made of other plastic materials). The experiments were inter alia. PVC, polyvinylidene fluoride, Polypropylene, polyethylene, polyvinyl fluoride and other plastics are used.

In one embodiment, a single component of the adhesive is used (Synthetic resin component or hardener) gently on the surfaces to be connected of the work parts applied so that a component of the adhesive is in the inner wall surface parts the clamp-shaped or U-shaped leg and / or on the base (groove base), the other Component on the surface parts to be connected of the edge part designed as a spring of the metal material part applied in a thin layer. When joining and pushing and / or pressing the molded parts through the direct contact of the components and their, by full or partial Mixing took place, chemical reaction resulting heat of reaction, the joining process accelerates and supports.

The invention thus also relates to the structural redesign as well the correct design and use of high-strength, integral connecting elements for plastic-metal constructions.

According to one embodiment, the high strengths are achieved by that by special expansion clamp connections an optimal material connection over a suitable adhesive is made possible.

The plastic-metal adhesive pairing is structured in such a way that all important functions are integrated in the plastic-side partner and from this can be taken over during the execution of the gluing. The connecting element on the plastic side should in the following, regardless of the type of manufacture, as an integrated expansion clamp # functional carrier, short (ISkF).

The function carrier should predominantly consist of partially crystalline plastomers can be produced with different degrees of crystallinity.

The invention is particularly concerned with technical parts to connect high strength, the z. B. in vehicle construction (body construction) and in structural engineering (Facade cladding) or should be used in other areas.

The problem of high joint strength is addressed in one embodiment solved in that the actually homogeneous plastic part by targeted, partial Stretching is reinforced in particularly stressed areas. So opened the possibility of increasing the connection strengths for these applications, what could previously only be achieved through composite construction.

The use of plastics in composite construction with metallic Materials is made more difficult by the fact that no welded connection is possible, therefore the force-locking or adhesive technology is used.

Bonding connections are, however, when it comes to butt-joint connections is extremely difficult to use.

For the proper implementation of an adhesive connection, the is constructive Correct formation of the edge regions is essential to ensure that the forces can be transmitted evenly.

The linear interlocking connections developed according to one embodiment are suitable for heavy-duty adhesive connections for technical applications provide.

Table: with details of the required separation forces Number of verses / connections Vers. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. line c #j RI 56.0 75.9 70.7 71.6 65.6 65.0 68.0 67.1 66.4 65.3 c 51 3.0 65.2 74.1 80.4 73.3 71.2 71.0 72.0 72.8 69.4 c 11.12.13.14.15.16.17.18.19.20. k Crack - - - - - - - - - E # ci 51 68.3 69.4 70.1 69.6 70.1 69.2 67.5 68.3 70.2 67.6 h C Specifications in daN / 100 mm connection length As mentioned above, the two-material adhesive connection consists of two fundamentally different elements, an elastic plastic part and a rigid metal partner, which form a unit after the joining process.

According to one embodiment, the plastic-side element is more symmetrical or asymmetrical Spreitz-Klemm-function carrier (SKF).

The following tasks are combined in it, depending on the embodiment: 1) During the joining process, it is elastically deformed (expanded), thereby exceeding the deformation does not have certain material limits.

2) The degree of deformation is precisely specified via the geometry.

3) After joining, the elastic parts are deformed back so that a certain joining pressure is built up 4) The SKF has a depot in which the glue is kept ready until use.

5) The shape of the SKF ensures that the adhesive during of the joining process is displaced from the depot and spreads evenly onto the adhesive surface distributed.

6) The direction of flow of the adhesive is opposite to the direction of joining.

7) The adhesive is hindered by integrated sealing elements at the outlet.

8) The contact pressure (joining pressure) required for gluing is in addition to the elastic recovery is also possible thanks to a spring-like design.

The metallic partner has the following tasks, depending on the embodiment: 1) increasing the stiffness of the connection, 2) pressing the glue out of the Depot, 3) opening up the plastic surfaces involved in the bond Frictional stress, temperature supply and removal, activation of the adhesive.

According to the method, gluing is therefore not only carried out via one Front edge joint, but at the same time through a two-sided overlap of the plastomer part to the metallic partner. The bond is therefore over a thermoset or Thermosetting plastics or another adhesive generated in the entire contact area.

A specially adjusted duromer adhesive thus generates on contact heat of reaction with the metal that is created when joining the joint. Simultaneously this heat of reaction causes the plastomer contact surfaces to melt ensures a network at this point.

During the reaction phase, the plastomer part becomes a more defined Pressure exerted on the surface. The bond created by pressure and temperature shows the high strength in all directions, as it is in such constructions are needed.

The thermoset or thermoset is thus activated by the metal.

After a. Embodiment, the metal is introduced warm and can trigger a reaction at the same time or subsequently or accelerate.

The thermoset or thermoset can, inter alia, a UP resin (PolV-urethane) Be epoxy resin or another two- or multi-component adhesive. Instead of one Duromer or

Druoplast adhesive can also be another adhesive, e.g. ß.

a plastomer adhesive can be used.

The glue is made from a reservoir that is constructive in the plastomer part is integrated, pressed out of these by the narrowing of the gap during joining and is evenly distributed over the area to be connected.

The structural design of the plastomer also enables one defined pressure on the adhesive (e.g.

Duromers) during bonding.

The stiffness of the plastomer is improved by the rib construction.

As already mentioned, the active surfaces of these plastomer parts have According to a preferred embodiment, undercuts, d. H. they are profiled.

When joining, the adhesive penetrates into these undercuts, and After hardening, there is a corresponding adhesive profile on the steel sheet educated. Both joining partners are thus positively connected.

The groove base is not always identical to the base of the groove, but rather can also be shifted a few millimeters forward. He is according to one embodiment shifted forward a few millimeters from the groove base and preferably has the largest there clear width of the groove. This denotes the greatest clear width of the groove in the vicinity the slot base (slot base or slot base) with coarse 3 A and the slot opening with small a, this results in an opening ratio A / a, which is defined by the inclination of the groove will. If A / a = 1, then there is a parallel groove, if A / a is greener than 1, a tapered one Groove and / or presence of sealing lips. Regardless of the presence of For sealing lips, the ratio A / a should be greater than 1.1. There will be no sealing lips is also used, the ratio of the opening widths should be between 1.2 and 2.0 lie.

Experimental example The glued samples were clamped and under Use of an upper and lower jaw and one with the lower jaw related traverse subjected to tension in which the traverse moved down (or up). The tensile strengths @@ in [N / mm2] are can be seen from the attached diagram, with a dependency on the selected Efficiency ratio (A / a) has been taken into account.

In the figures, a plastic part with the clamp-like or U-shaped legs that delimit the groove is shown schematically in FIG. 1. Under (A) the largest clear width of the groove base, which is a few millimeters away from the groove base in the embodiment shown, is shown. The clamp-like or U-shaped legs are inclined towards one another and form a groove which tapers towards the groove opening (a). The following arm measurements were chosen for the tests: A = 2.5 mm B = 25.0 mm C = 8.0 mm D = 1.0 mm L = 90.0 mm lüred. = 5 mm 1 = lü = lückez. = 10 mm lümax. = 15 mm, where under 1 the length of the surfaces used for gluing is shown.

In Fig. 2 the bonding and an embodiment of the with the groove provided plastic part shown schematically. The bracket-shaped or u-shaped Legs (1) delimit the groove (4) and have sealing lips in the vicinity of the groove opening (2) on. The sealing lips can also be in the area of the middle of the groove or between the middle of the groove and groove opening be attached. The groove base (3) contains shown schematically an amount of adhesive that adopts a flow direction when the metal part is inserted, which is shown schematically by the arrows. The metal part (7) is with its, possibly profiled edge (as a tongue) into the groove (4) of the plastic part (8) inserted. The figure below shows schematically that with the metal part and glued plastic part.

In Fig. 3, the groove opening of the plastic part is in the upper sketch closed by a thin sealing sleeve, which when inserting the metal part is cut open and attached to the inner surfaces of the clamp-shaped or U-shaped legs and is embedded by the adhesive during the joining process.

The drawing below shows schematically the one with grooves (6) provided inner wall surfaces of the clamp or. u-shaped leg, the sealing lip (2) and the Groove base (3) of the plastomeric material part (8), the preferably flat (plate or shaped plate) is formed.

FIGS. 2 and 3 are merely schematic representations.

In Fig. 4, the average tensile shear strength achieved is shown in the diagram «CN / mm21 shown as a function of the aperture ratio A / a.

In the diagram are above the actual aperture ratios Mean values of the individual series of measurements, each representing a certain shape, applied.

Claims (16)

Claims 17 A method for joining plastomeric materials and metals by means of a solidifying adhesive, preferably a duromer adhesive, characterized in that the bond is not only via a front edge joint, but at the same time by a two-sided overlap of the plastomer part around the metallic partner takes place. 2. The method according to claim 1, characterized in that the groove or groove opening of the plastomeric material part contains a sealing element or it forms and the groove is used as a depot for the adhesive or for an adhesive component is or is formed. 3. The method according to claim 1, characterized in that the groove is limited by clamp or U-shaped legs, the inner leg surface are inclined towards each other, so that one (viewed in the unattached state) to the groove opening tapered groove is formed. 4. Process according to Claims 1 to 3, characterized in that the tapered groove is bent or widened when the metal part is inserted is, whereby an additional force effect and thus increased connection strength for the gluing arises. 5. Process according to Claims 1 to 3, characterized in that the tapered groove is not or only slightly widened when the metal part is inserted and an adhesive wedge forms in the Nuthohiraum, which leads to a raised Bond strength leads. 6. Process according to Claims 1 to 5, characterized in that the groove contains grooves or ridges into which the adhesive is poured during bonding or is embedded, and thus causes an increased connection strength. 7. Process according to Claims 1 to 6, characterized in that on the inner wall parts of the bracket-shaped or U-shaped legs that enclose the groove, Sealing elements are present that are embedded in the adhesive during gluing. 8. The method according to one or more of claims 1 to 7, characterized characterized in that the plastomer part to be connected has a groove extending from the inner wall parts the two bracket-shaped or U-shaped legs is limited, the opening width of the groove base is greater than or approximately equal to the cross-sectional thickness of the outer, formed as a tongue edge part of the metal material part is that the groove or Groove opening of the plastomeric material part contains sealing elements and / or through them one or more groove constrictions (cross-sectional constriction of the groove) in the vicinity of the The groove opening or between the groove center and the groove opening itself and that the groove base, Sealing element and inner wall parts of the clamp-like or U-shaped legs are formed Space serves as a depot for an adhesive or an adhesive component. 9. The method according to one or more of claims 1 to 8, characterized characterized in that the plastomer part to be connected has a groove formed by two clamps or U-shaped legs is limited, wherein the spring end of the metal part not thicker in terms of its cross-sectional diameter on the outer tongue edge part is than the opening width of the groove base and the adhesive or an adhesive component is brought into the depot prior to joining, which is formed by groove base, inner wall surface parts, the clamp or the groove delimiting. u-shaped legs and one or more between the groove center or groove opening and / or sealing elements located on the groove opening limited and / or formed becomes, the one similar to a channel, in cross-section Has a circular, wedge or triangular, elliptical, rectangular or parabola-like shape. 10. The method according to claims 1 to 9, characterized in that the sealing elements are made of the same plastomeric material as that with the Metal part to be connected plastomeric material part and approximately parallel or run at an angle or with the outer edge of the bracket-shaped or U-shaped legs. 11. The method according to claims 1 to 10, characterized in that at least one sealing element is designed as a sealing sleeve, starting from the Edges of the two clamp or U-shaped legs or of the inner wall parts of the clamp-like or U-shaped leg, the groove opening or one between the middle part the groove and the groove opening lying groove space along the plastomer to be connected Part of the material encloses thin-walled. 12. The method according to any one of claims 1 to 10, characterized in that that the sealing element by overlapping or bumping into each other each of a groove opening and / or each of an inner wall surface of the clamp-like or U-shaped legs from the projecting sealing lips or by formation two or more mutually extending sealing lips that pass through a slot separated with a small opening width in the middle or almost in the middle are formed. 13. The method according to claims 1 to 12, characterized in that the inner wall parts of the clamp or U-shaped legs are provided with grooves, which the form-fitting Support connection. 14. The method according to claims 1 to 13, characterized in that the grooves parallel or at an angle to the outer edge of the bracket-shaped legs get lost. 15. The method according to claims 1 to 14, characterized in that the grooves have different depths and different distances from one another. 16. The method according to claims 1 to 15, characterized in that the groove depths increase towards the groove opening.