Method of manufacturing a tank of thermoplastic material including a portion in relief for mounting an attachment, and a tank manufactured thereby

Abstract

A method provides a tank out of blown, thermoformed, or rotomolded thermoplastic material with a portion in relief for enabling mounting of an attachment inside the tank. The method includes making the portion in relief on the inside of the tank, the portion in relief enabling an attachment to be mounted inside the tank. The portion in relief is made by mounting a mounting member on the wall of the tank. Preferred mounting is by heat-sealing. The wall of the tank includes at least a layer of thermoplastic material and preferably includes a layer that forms a barrier against hydrocarbons. A tank with a portion in relief mounted on an inside wall is also provided.

Description

INCORPORATION BY REFERENCE [0001] This is a division of application Ser. No. 09 / 824,051 filed Apr. 3, 2001, the disclosure of which is hereby incorporated herein by reference in its entirety.BACKGROUND [0002] The present invention relates to a method of making a tank of blown, thermoformed, or rotomolded thermoplastic material. More particularly, but not exclusively, the invention relates to making a fuel tank for a motor vehicle. [0003] A fuel tank must be designed to prevent fuel being lost through its wall, in particular by diffusing through the thermoplastic material. [0004] To do this, it is known that the tank can be made from a multi-layer parison that includes a barrier-forming layer constituted by a material having good impermeability to hydrocarbons both in gaseous and in liquid form. [0005] By way example, such a layer can be based on EVOH. [0006] In general, a tank made in this way gives satisfaction concerning hydrocarbon emissions. [0007] It is also necessary to be abl...

AI Technical Summary

Benefits of technology

[0018] The invention makes it possible to provide a shape for mounting an attachment inside the tank without any need to cut through or pierce the wall of the tank, and this is particularly advantageous when the wall in question includes one or more layer(s) forming a barrier against hydrocarbons.

[0047] In a preferred embodiment, the parison has two layers of thermoplastic material, with a layer forming a barrier against hydrocarbons sandwiched between them. The outer layers thus protect the barrier-forming layer against mechanical damage.

Problems solved by technology

The attachment then projects into the inside of the attachment, thereby reducing the height available for performing the function for which the attachment, in particular a valve, is provided, and that can reduce the maximum depth of fuel that can be received by the tank, and thus reduce the capacity of the tank.

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