DE10062154A1 - Blow molding thermoplastic containers for fuel or other fluid storage involves coating the inside of a preform and compressing before inflating to form a container with an internal anti-splashing structure - Google Patents

Abstract

A coating, which when heated becomes viscous and tacky, is applied to the inside of a tubular thermoplastic plastic preform and the preform compressed such that both inner surfaces contact each other. The compressed preform is then placed in a blow molding tool(4) and inflated under pressure(P2) to produce a container. When the container inflates a thread-like structure(5) is formed transversely between the container walls which reduces noise and splashing. An Independent claim is made for a container for fuels and other fluids produced by the claimed process and incorporating a thread like structure to prevent splashing and noise.

Description

The invention relates to a method for producing a container for fuels or other liquids made of a thermoplastic as well as the container the container being made by blow molding and sloshing inside and has noise cancelers.

Liquid containers, such as B. fuel tanks on motor vehicles are in increasingly produced by blow molding, preferably a pipe or tubular hollow body made of a possibly fuel-resistant, however thermoplastic, which can be polyethylene, heated, in a blow mold introduced and exposed to such high internal pressure that Wall clings in plastic state to the inner contour of the blow mold and after has the desired contour of the container after cooling.

Such a manufacturing process is essentially EP 0 556 552 B. remove, during the blow molding of a hollow body made of thermoelastic Plastic also a so-called surge pot on the inner wall of the Hollow body, for example a fuel tank, is attached, which in turn is therefor ensures that regardless of the fuel acting in the tank Forces such as B. centrifugal forces when cornering, in the area of the intake for Fuel pump always has enough fuel available.

From practice, however, it is also known that liquids such as fuels are used in Fuel tanks, generate annoying sloshing noises while driving.

In order to counter this maladministration, there are various technical solutions been disclosed.  

DE 39 43 710 C proposes, for example, in a fuel tank Arrange so-called baffle elements, which consist of a plastic material and held between the walls of the fuel tank using Heat is fixed or attached to a holder within the fuel tank.

With these impact elements, the waves should be broken and the sloshing noises, also referred to as impact noises can be reduced.

Certainly a reduction of the same can be achieved with this measure, however the Assembly of such a two-part, consisting of upper and lower shell Fuel tanks, the manufacture of the impact elements and the definition of the same within the fuel tank assessed as complicated and expensive.

Solutions are also known from DE 196 50 415 C and DE 197 29 818 A, which provide a plurality of damping elements or porous fillers which swim freely inside the tank or fill it completely.

The object of the present invention is to use blow molding simple and inexpensive method for producing a container from a thermoplastic for fuels or other liquids with integrated so-called slosh and noise killers.

It is also an object of the invention to produce one which can be produced by this method Specify container.

According to the invention, the object is achieved by a method for producing a container for fuels or other liquids made of a thermoplastic, being on the inner surface of a tubular or tubular hollow body made of this thermoplastic an inner coating is applied, at least has a viscous and sticky texture when heated, hereinafter the Hollow bodies placed in a plastic state due to heating and thus with a pressure "P1" that the two are forming contact opposite inner surfaces with each other and finally the compressed hollow body by blow molding such an increased internal pressure "P2" is exposed, that its wall in plastic state adjoins the  Inner contour of a blow mold, forming the desired contour of the container, hugs and that is in a viscous sticky state Internal coating at least during the blow molding of the hollow body threadlike structure that runs across the extends from the hollow body in the form of the desired container.

In one embodiment of the invention, the inner coating is almost solid non-sticky state in the tubular or tubular hollow body thermoplastic introduced and then by heating in one viscous sticky state, with the original after cooling almost solid non-sticky state is achieved.

In another embodiment of the invention, the inner coating is in one. viscous, possibly heated state on the inner surface of the pipe or applied tubular hollow body, being after cooling or a Drying an almost solid non-sticky state is achieved.

In this case, it makes sense to have the inner coating in one viscous, possibly heated state on the inner surface of the pipe or to spray or spread on tubular hollow body.

It is also proposed that the inner surface of the tubular or tubular Hollow body is provided over the entire surface or in sections with the inner coating.

An advantageous development provides for the inner surface of the tubular or hose-like To provide hollow body with a net-like distributed inner coating.

Furthermore, it is proposed to use a plastic or an inner coating Use synthetic resin.

The container for fuels or other liquids made by blow molding a hollow body made of a thermoplastic, is particularly notable characterized in that the hollow body in the form of the container is at least one inside the same thread-like extending across the enclosed space Forms as sloshing and noise eliminators.  

In a development of the container according to the invention, the thread or threads are supported Form on the inner surface of the container

Furthermore, it is considered to be according to the invention that the thread-like structure consists of a material that is viscous and sticky at least when heated and after cooling or drying, an almost firm, but elastic to some extent Shows quality.

As the invention further provides, the thread-like structure almost extends orderly aligned or disordered across the enclosed space of the Container.

As the invention finally provides, the thread-like structure consists of one Plastic or a synthetic resin.

With regard to the prior art, the proposed method has the advantage that a container with just a few simple steps can be made of thermoplastic, which in turn is already effective acting, namely waves breaking, slosh and noise eliminators, the for its part not manufactured separately outside of the container and subsequently in this must be introduced, but in one step with the blow molding of the container itself and be fixed to the wall of the same.

Furthermore, the volume is reduced by the above sloshing and Noise reduction to be estimated as low.

The invention is illustrated below with reference to one in the drawings illustrated embodiment explained in more detail.

Show it:

Fig. 1 shows a sectional view of a tubular or hose-like hollow body of thermoplastic material with inserted inner coating,

FIG. 2, the situation during compression of the hollow body,

Fig. 3 shows the situation after the blow molding of the container from the compressed hollow body according to FIG. 2.

Fig. 1 shows a tubular or tubular hollow body 1 , which in turn consists of a thermoplastic material and serves as a preferred starting workpiece for the production of containers, such as fuel or other liquid containers, by the blow molding process.

As already shown above, it is appropriate to use so-called To provide slosh and noise eliminators that are suitable in turn, for example waves caused by the driving of the motor vehicle to break and the Reduce sloshing noises.

According to the invention, an inner coating 2 is accordingly applied in the tubular or hose-like hollow body 1 , which in turn consists of a material which, at least when heated, has a viscous and sticky nature.

Suitable materials are, for example, synthetic resins or similar Viewed plastics.

On the one hand, there is the possibility of introducing the inner coating 2 into the tubular or hose-like hollow body 1 in an almost solid, non-sticky state, and subsequently to bring it into a viscous, sticky state by heating.

Tubular or hose-like structures are also suitable for this purpose, which are introduced into the space enclosed by the hollow body 1 .

On the other hand, it can also be expedient to preheat the inherently solid material of the inner coating 2 , accordingly to put it in an injectable, preferably viscous state and then to apply it to the inner surface of the hollow body 1 by spraying or brushing.

Furthermore, there is the possibility of using an inner coating 2 , which originally has a preferably viscous nature and only hardens by drying, if appropriate using heat, and thus has an almost solid, non-tacky state.

After the inner coating 2 has been applied, the tubular or hose-like hollow body 1 is brought into a plastic state as a result of heating and is compressed by means of pressing devices (not shown) which are known per se, with a pressure "P1" such that the two opposing inner surfaces 3 that form a; 3 b contact with each other ( Fig. 2).

Gem. Fig. 3 is finally the compressed hollow body 1 transferred in a per se known blowing mold 4 and subjected to such increased inner pressure "P2", at its wall the desired contour of the container that in the plastic state to the inner contour of the blow mold 4, ausbildend, snugly.

During the blow molding of the compressed hollow body 1 , due to the previous contacting of the two inner surfaces 3 a; 3 b from the inner coating 2 thread-like structures 5 which extend across the space enclosed by the hollow body 1 .

Depending on the type of material used for the inner coating 2 , the thread-like structures 5 harden after cooling or after drying, possibly in conjunction with the supply of heat, and have an almost firm but, to a limited extent, elastic nature.

Is easy to understand for the skilled person that depending on the chosen distribution of the internal coating filamentary 2 within the hollow body 1 and the distribution of extending in the space enclosed by the hollow body 1 and space on the inner surfaces 3 a, 3 of the same or the inner surface b of the container is supported Form 5 results.

Accordingly, the inner surface of the tubular or tubular hollow body 1 can be provided with the inner coating 2 over the entire surface or in sections.

In a preferred embodiment, a net-like inner coating 2 is aimed for, which results in thread-like structures 5 which, in an approximately aligned manner, extend across the enclosed space of the container which is finished per se ( FIG. 3).

However, it may also be intended to produce thread-like structures 5 which extend in a disorderly manner across the enclosed space of the container, where appropriate not only being supported exclusively on the inner surface of the container, but also being mutually supported as a result of further points of contact (not shown in more detail).

According to the above-described method, a container made of thermoplastic material can accordingly be produced, which has a plurality of thread-like ones extending within the same across the enclosed space. Form 5 has so-called slosh and noise eliminators.

By means of these slosh and noise eliminators, breaking becomes possible, for example while driving a motor vehicle in the fuel tank or container forming waves of liquid fuel guaranteed.

Claims (12)

1. A method for producing a container for fuels or other liquids made of a thermoplastic, an inner coating ( 2 ) is applied to the inner surface of a tubular or tubular hollow body ( 1 ) made of this thermoplastic, which has a viscous and sticky at least when heated having texture, below the hollow body (1) due to heating in a plastic state and is set in such a manner pressed together with a pressure "P1" that the two forming opposing inner surfaces (3 a, 3 b) contact with each other and finally the compressed hollow body (1 ) is subjected to such increased internal pressure "P2" by blow molding that its wall clings in the plastic state to the inner contour of a blow mold ( 4 ), forming the desired contour of the container, and the inner coating, which is in a viscous, sticky state ( 2 ) during the blow molding of the hollow body ( 1 ) pulls at least one thread-like structure ( 5 ) which extends as a slosh and noise eliminator across the space enclosed by the hollow body ( 1 ) in the form of the desired container. 2. The method according to claim 1, characterized in that the inner coating ( 2 ) is introduced in an almost solid non-tacky state in the tubular or tubular hollow body ( 1 ) made of thermoplastic material and is subsequently brought into a viscous sticky state by heating, after cooling, the original almost solid non-sticky state is achieved. 3. The method according to claim 1, characterized in that the inner coating ( 2 ) is applied in a viscous, optionally heated state to the inner surface of the tubular or tubular hollow body ( 1 ) and achieves an almost solid non-sticky state after cooling or drying becomes. 4. The method according to claim 3, characterized in that the inner coating ( 2 ) is sprayed or brushed onto the inner surface of the tubular or tubular hollow body ( 1 ) in a viscous, optionally heated state. 5. The method according to any one of claims 1 to 4, characterized in that the inner surface of the tubular or tubular hollow body ( 1 ) is provided over the entire surface or in sections with the inner coating ( 2 ). 6. The method according to any one of claims 1 to 5, characterized in that the inner surface of the tubular or tubular hollow body ( 1 ) is provided with a mesh-like inner coating ( 2 ). 7. The method according to any one of claims 1 to 6, characterized in that a plastic or a synthetic resin is used as the inner coating ( 2 ). 8. Container for fuels or other liquids, produced by blow molding a hollow body from a thermoplastic, characterized in that the hollow body ( 1 ) in the form of the container at least one thread-like structure ( 5 ) extending within the same across the enclosed space as a slosh - And has noise cancellation. 9. A container according to claim 8, characterized in that the thread-like structure ( 5 ) is supported on the inner surface of the container. 10. Container according to one of claims 8 and 9, characterized in that the thread-like structure ( 5 ) consists of a material which, at least when heated, has a viscous and sticky and, after cooling or drying, an almost solid, but to a certain extent elastic. 11. Container according to one of claims 8 to 10, characterized in that the at least one thread-like structure ( 5 ) extends almost ordered or disordered across the enclosed space of the container. 12. Container according to one of claims 8 to 11, characterized in that the thread-like structure ( 5 ) consists of a plastic or a synthetic resin.