DE8520156U1 - Containers for liquids, in particular fuel tanks made of thermoplastic material - Google Patents

Description

PATENTI NQ EN I £ UR
Dipl, -Landw, F>, Thielmann
βutupian paintl (Attorney

At eeohenbaro 14 - Tel. COS4eO

D-366 O BIEDENKOPF / LAHN

06 13 ^ Ei kämet

APPLICANT

ELKAMET-WERK Lahn-Kunststoff GmbH, Georg-Kramer-Stfäßes, D-3560 Biedenkopf

TITLE N UN 6

Containers for liquids, in particular fuel tanks from a thermoplastic. plastic

The invention relates to a container for liquids produced in a rotational molding process, in particular a fuel tank made of thermoplastic material with a multilayer wall.
5

For containers made of thermoplastic material for mixed Fuels have the problem that - depending on the type of fuel - certain components of the fuel mixture diffuse through the container wall. A Polyethylene containers, for example, exhibit greater permeation of hydrocarbons from the mixture; however, it is almost impervious to alcohol. A container made of polyamide 6, on the other hand, is against hydrocarbons almost tight, but leaves some alcohol diffuse.

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For fuels made from blends that are so different Components exist - would be a tank with a multilayer wall required.

Fuel tanks with multilayer walls are be ^ relts known. The EPS 0 069 303 is a double-walled Tank; especially for the storage of gasoline, solvents, acids, alkalis and oils, in toilet 1 brazen between the outer wall and the inner wall Spacer Provided in the form of a corrugated metal foil is, the inner wall made of a sprayed onto the metal foil, reinforced with fibers and on Epox1d-Sch1cht tested for freedom from pores and one on this sprayed-on electrically conductive epoxy layer consists.

Such containers are practically impermeable to all components of the liquids mentioned. However Is the production extremely complex. Another Disadvantage is that with these features practically only larger tanks with simple geometric Forms can be produced.

Smaller fuel tanks in vehicles or the like Containers in possibly complicated shapes with the Features according to EPS O 069 303 can practically not be produced at all.

After the rotation casting process, however, can be with relatively cheap molds practically all Manufacture desired shapes of fuel tanks. Included the production of series with smaller quantities is still economical, at least a lot more economical than other methods, e.g. according to a blow molding process.

However, this method can also be used to with a multilayer wall.

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Up to now, however, no fuel tanks produced by the rotary process have been known whose walls are multilayered in such a way that the different layers are impermeable to different liquids or their vapors. So far, for example, it has not been possible to manufacture containers using the rotational molding process, the outer layer of which is made of polyethylene and the inner layer of a polyamide, since these two materials cannot easily be connected to one another in a durable manner.

The invention is therefore based on the object of providing a liquid container that can be produced using the rotary casting process, especially fuel tank, to reveal its Wall is multilayer, such that the different Wall layers for the various components, e.g. hydrocarbons and alcohols, one mixed Liquid, e.g. a fuel mixture or its Vapors are impermeable to the various wall layers are firmly and inextricably linked.

The object set is achieved according to the invention by that the container wall has at least two layers of different, not immediately solid and insoluble interconnectable thermoplastics having, between these layers at least one adhesion promoter layer from the added means Propellant is assigned to a foam-forming plastic of the outer layer and / or the inner layer.

Further features of such a container emerge from claims 2 to 5.

The container according to the invention is based on the following a drawing showing an embodiment explained in more detail.

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Show it!

P ¹ Ig, a fuel tank for motorcycles in plan view.,

Fig * 2 shows a greatly enlarged cross-section through a

Section of the tank wall ,
5

The fuel tank is lltf rotary pouring process made of thermoplastic material. After this Procedure is practically any form adaptation of an ergonomic type and to the other components of the vehicle

10 'I can. The tank is double-walled in such a way that it has an outer layer 1 made of polyethylene and an inner layer 2 made of polyamide 6. These two layers are firmly and permanently connected to one another by an adhesion promoter layer 3. The adhesion promoter layer 3 consists of foamed polyethylene. This is a closed-cell foam made of the same material as the outer layer 1, but with the addition of a propellant.
The adhesion promoter layer 3 and the outer layer 1 thus also form a layer as seen in terms of the material

k "heterogeneous cross-section such that a compact outer

Ί layer 1 on the inside with a foamy surface is provided, on which an inner layer 2 is molded from a different material. 25th

The outer layer 1 and the adhesion promoter layer 3 are

impermeable to alcohol components of a fuel

'_; mixed. The inner layer 2 made of polyamide 6, however

Jg. Is impermeable to hydrocarbons.

3 0

Of course, other combinations are also in the same way of plastics possible. The adhesion promoter ^

; ' Layer 3 can, for example, also consist of the material of the inner layer 2 exist to which a foaming agent has been added to form foam.

They can also be designed as a double layer, DEI l \

art that the outer half is made of foamed material of the *

Outer layer and the inner half of foamed Mate \ l

rial of the inner layer. l |

Further, the multiple layers of the wall is not limited to ^l, the combination of polyethylene and polyamide. 6

Claims (5)

PATENT ENGINEER ·. · Dipl.-Landw, P, Thielmann ßutopean Patent c / Bffocneu Am Eschsnbero M - Tel. CO6} 2733 D-3SBO B I E D E N KO PF / LAH N 06 13 - El kämet ELKAMET-WERK Lahn-Kunststoff GmbH PROTECTION CLAIMS 1. Rotational molded container for Liquids, especially thermoplastic fuel tanks Plastic with multilayer walls, characterized in that £ the Behaiterwandung at least two layers (1, 2) of different, not immediately fixed and inseparable interconnectable thermoplastics having, between these layers at least one adhesion promoter layer (3) from the Forming a foam by a given propellant Plastic of the outer layer CO and / or the inner layer (2) is arranged. 2. Container according to claim 1, characterized in that its wall has an outer layer (1) made of polyethylene and an inner layer (2) made of Has polyamide. 3. Container according to claims 1 and 2, characterized marked that the between the outer layer (! O made of polyethylene and the inner layer (2) adhesive layer made of polyamide C3) consists of foamed polyethylene, iiit # * ■ II 1111 4. Container according to claims 1 and 2, characterized marked that the between the outer layer CD made of polyethylene and the inner layer C2} adhesive layer made of polyamide C3) consists of foamed polyamide. 5. Container according to claims 1 and 2 , characterized characterized in that between the outer layer CD made of polyethylene and the inner layer C2) made of polyamide, two layers of adhesion promoter arranged are, the outer adhesion promoter layer made of foamed Polyethylene and the inner adhesive layer is made of foamed polyamide. I IM ',' ■ ι. · Ι · III