Process for manufacturing vehicle headliners

Abstract

Manufacturing process for vehicle headliners comprising a substrate and at least one decorative lining extending along one of the faces of said substrate, joined to each other through a layer of adhesive, which specifically comprises the union of the decorative lining to the previously shaped substrate using a thermosetting adhesive with a high viscosity.

Claims

1. Process for manufacturing vehicle headliners comprising the following stages: a) arranging a previously shaped three-dimensional substrate and a decorative lining; b) applying a layer of thermosetting adhesive with a Brookfield viscosity between 1000 and 2500 mPa.Math.s measured at 25 C. with a no. 3 spindle and rotational speed of 20 rpm on the decorative lining; c) introducing the shaped three-dimensional substrate in a thermoforming mould at a temperature between 110 and 150 C.; wherein a predetermined shape of the thermoforming mould corresponds to the previously shaped three-dimensional substrate; d) introducing the decorative lining together with the layer of thermosetting adhesive on the shaped three-dimensional substrate such that the layer of thermosetting adhesive is in front of the shaped three-dimensional substrate; e) closing the thermoforming mould and applying pressure to establish the union between the decorative lining and the shaped three-dimensional substrate through the layer of thermosetting adhesive; f) opening the thermoforming mould and extracting the headliner.

2. Process for manufacturing vehicle headliners according to claim 1, wherein the adhesive application stage b) is performed using adhesive application rollers.

3. Process for manufacturing vehicle headliners according to claim 1, wherein the layer of thermosetting adhesive after setting on the headliner obtained in stage f) has a grammage of 10 to 35 g/m.sup.2.

4. Process for manufacturing vehicle headliners according to claim 1, wherein said stage d) further comprises stretching the decorative lining so that the lining remains taut.

Description

DESCRIPTION OF THE DRAWINGS

(1) The present specification is complemented by a set of figures that illustrate a preferred embodiment, in no way limiting the invention.

(2) FIG. 1 shows a schematic view of the stages of the headliner manufacturing process.

(3) FIG. 2 shows a method for applying high-viscosity thermosetting adhesive to the decorative lining.

DETAILED DESCRIPTION

(4) The headliner manufacturing process begins with stage a), which comprises arranging a previously shaped substrate (2) and a decorative lining (1).

(5) Said shaped substrate (2) consists of one or several layers and has a mainly structural function, that is, supporting the typical loads of a headliner first during its handling, and then during the lifetime thereof when assembled on the vehicle.

(6) The layer or layers forming said shaped substrate (2) can be shaped for example by thermoforming processes, that is, using processes in which heat and pressure are applied simultaneously, or by forming processes using pressure. In both cases the objective is to obtain a specific geometry.

(7) The decorative lining (1) forms the visible face of the headliner (10) when assembled in the vehicle, and therefore has a decorative function.

(8) Said decorative lining (1) can comprise several materials and structures commonly employed in the field of vehicle headliners.

(9) After arranging the main components of the structure of the headliner (10) the next stage of the process begins, stage b), which involves applying a layer of thermosetting adhesive (3) with a Brookfield viscosity between 1000 and 2500 mPa.Math.s measured at 25 with a No. 3 spindle and rotational speed of 20 rpm on the decorative lining (1) to join the shaped substrate (2) and the decorative lining (1) in a subsequent stage.

(10) The thermosetting adhesive layer (3) is applied with adhesive application means (4) allowing a controlled and even distribution of adhesives with high viscosity.

(11) Specifically, FIG. 2 shows an example of adhesive application means (4) comprising adhesive application rollers (4.2, 4.3) consisting of a first roller (4.3) for adhesive dosing in contact with the thermosetting adhesive contained in a vessel (4.4) for application on the decorative lining (1) which moves between said first dosing roller (4.3) and a second support roller (4.2), in order to apply a layer of thermosetting adhesive (3) on the decorative lining (1) with a controlled and even thickness.

(12) Another example, not shown, can comprise a doctor blade that controls the deposition of thermosetting adhesive on the decorative lining (1), making the adhesive flow as a continuous sheet with the aid of said blade in order to deposit a layer of thermosetting adhesive (3) on the decorative lining (1) in an even and controlled manner.

(13) After applying the layer of thermosetting adhesive (3) on the decorative lining (1), stage c) is performed which involves introducing the shaped substrate (2) in a thermoforming mould (5).

(14) Said thermoforming mould (5), the shape of which corresponds to that of the shaped substrate (2), comprises a first mould half (5.1) and a second mould half (5.2) and is at a temperature between 110 and 150 C.

(15) Stage d) then begins, comprising introducing the decorative lining (1) with the layer of thermosetting adhesive (3) applied in stage b) on the shaped substrate (2) such that the layer of thermosetting adhesive (3) is in front of the shaped substrate (2).

(16) For this purpose, the second mould half (5.1) can include stretching means (5.1.1) for the decorative lining (1) to ensure sufficient tautness thereof. In this way, when the mould is closed the appearance of wrinkles on said decorative lining (1) is prevented.

(17) The next stage e) comprises closing the thermoforming mould (5) and applying pressure on the decorative lining (1) and the shaped substrate (2) to join the two with the layer of thermosetting adhesive (3) by the combined application of heat and pressure.

(18) In stage e) the decorative lining (1) is stretched and is adjusted to the geometry of the shaped substrate in order to establish the union of the two throughout the entire contact surface.

(19) Finally, stage f) comprises opening the thermoforming mould (5) and removing the headliner (10) with a specific geometry.

(20) Preferably, the resulting adhesive layer, once the adhesive has set, in the headliner obtained has a grammage of 10 to 35 g/m.sup.2, confirming the reduction in adhesive material used in the manufacturing process of the invention.