WO2002018478A2

WO2002018478A2 - Process of integrating decorative layers onto an interior trim article

Info

Publication number: WO2002018478A2
Application number: PCT/US2001/027271
Authority: WO
Inventors: Alex J. Kaminski; Michael W. Muench; Timothy F. O'brien
Original assignee: Intier Automotive, Inc.
Priority date: 2000-08-31
Filing date: 2001-08-31
Publication date: 2002-03-07
Also published as: AU2001287008A1; WO2002018478A3

Abstract

The invention is a method for manufacturing an article having multiple layers. These mutiple layers have differing surface areas. The method incorporates the use of a mold assembly having a first mold portion (50) and a second mold portion (60). The two mold portions define a mold cavity having first and second mold surfaces (52, 62). The first and second mold surfaces define first and second surface areas, respectively. The method includes the steps of placing a first layer (32, 34) of material on the first mold such that the first layer of material extends along a portion of the first mold surface (52). A second layer is applied to the first mold surface (52) over the first mold cavity and the first layer. The second layer extends over the first layer and the entire first mold surface (52). A pressure is then applied within the mold cavity to form the article.

Description

PROCESS OF INTEGRATING APPLIQUES ONTO AN INTERIOR TRIM ARTICLE

BACKGROUND ART

1. Field of the Invention

The invention relates to a process of making interior trim articles mountable in an interior of a motor vehicle. More specifically, the invention relates to a process of making interior trim articles having one or more different layers of material or appliques visible when mounted within an interior of a motor vehicle.

2. Description of the Related Art

Interior trim articles such as instrument panels, door panels, armrests, headrests, floor consoles, glove compartment doors and the like generally include a relatively soft decorative layer or skin covering a rigid substrate, which is mountable in the vehicular body to a particular structure or other interior trim article.

Commonly, a cellular polyurethane padding is interposed between the skin and the rigid substrate to provide the skin with a compressive feel. For added decorative appearance, layers of other material and/or appliques are often adorned to the front surface of the skin for enhancing the decorative appearance of the article. These pieces usually have exposed surfaces with wood grain or metallic designs which surface towards the vehicle interior when the article is mounted to the vehicle body. Although it is known to form appliques from wood or metallic materials, more often the appliques are formed, at least in part, from a plastic material having the feel and appearance of the design the part is replicating.

One conventional method for making such interior trim articles is shown in Figure 5. In this instance, an applique 10 includes a decorative portion 12 having a particular pattern, such as by cutting a stock sheet or roll. The applique 10 also includes a structural component 14. The structural component 14 of the applique 10 is fabricated from a suitable polymeric material, such as acrylonitrile-butadiene-styrene copolymer (ABS).

Separately, the relatively soft layer or skin 16 is prepared from a patterned polymeric film, such as a polyurethane or poly( vinyl chloride) (PNC). The polymeric film is applied against a second mold surface having a configuration that is substantially complementary to the desired configuration of the exposed surface of the interior trim article. However, the second mold surfaces is provided with one or more protrusions and indentations having corresponding configurations to the appliques 10. The polymeric film is vacuum thermoformed against the second mold surface in a traditional manner. For example, a carrier frame typically delivers the polymeric film in a preheated state to the second mold surface, where the polymeric film is clamped and sealed against at the edges of the second mold surface. A vacuum is applied at the second mold surface to urge the polymeric sheet against the first mold surface so that the polymeric sheet assumes a configuration complementary to the second mold surface. The reconfigured polymeric sheet is then cooled to form the skin 16 and is removed from the mold. The protrusions and indentations formed on the second mold surface cause complementary recesses to be formed in the surface of the skin 16. Next, the skin 16 is transferred to a third mold surface, where the skin 16 is united with a reinforcing substrate 18 carried on a fourth mold surface. Optionally, a cellular foam precursor material (not shown), such as polyols and polyisocyanates with a blowing agent, is sprayed between the skin 16 and reinforcing substrate 18 and allowed to foam and thereby unite the skin 16 and reinforcing substrate 18. The resultant panel 20 is removed from the molds.

After the separate formation of the appliques 10 and the panel 20, the applique 10 (and rug portion 22 as shown in Figure 5) are placed into complementary recesses formed in the surface of the skin 16 so that the applique substrates 14 abut against the recesses of the skin 16, and so that the appliques 10 are exposed when the panel 20 is mounted in a vehicle interior. Conventional fastening means, such as bolts, rivets, and screws, are commonly used to retain the appliques 10 against the skin 16 and substrate 18. Implementation of such fastening means can be accomplished by forming boring holes, bosses, and the like in the appliques 10 and the panel 20 during molding or via post-molding procedures. In Figure 5, a hole 24 is bored through the panel 20 to receive a clamp similar to clamp 26.

This conventional process is, however, relatively labor intensive and time consuming due to separate formation of the panels and the applique substrates and the requirement for subsequent fastening steps to attach the reinforced appliques to

the interior trim panels.

SUMMARY OF THE INVENTION The invention is a method for manufacturing an article having multiple layers. These multiple layers have differing surface areas. The method incorporates the use of a mold assembly having a first mold portion and a second mold portion. The two mold portions define a mold cavity having first and second mold surfaces. The first and second mold surfaces define first and second surface areas, respectively. The method includes the steps of placing a first layer of material on the first mold cavity such that the first layer of material extends along a portion of the first mold surface. A second layer is applied to the first mold surface over the first mold cavity and the first layer. The second layer extends over the first layer and the entire first mold surface. A pressure is then applied within the mold cavity to form the article.

BRIEF DESCRIPTION OF THE DRAWINGS Advantages of the invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein: Figure 1 is a sectional, partially exploded perspective view of an interior trim article made in accordance with an embodiment of this invention;

Figure 2 is a sectional view of a mold surface showing a step of applying appliques onto a first mold surface in accordance with an embodiment of this invention; Figure 3 is a section view of the mold surface of Figure 2 having the appliques applied thereto, showing the next step of applying a heated polymeric film to the rear of the appliques and the exposed portions of the mold surface to form a skin;

Figure 4 is a sectional view of the mold surface of Figure 3 having the skin with the appliques integrated thereon, showing the step of uniting the skin with its integrated appliques to a reinforcing substrate via polyurethane foam precursor materials; and

Figure 5 is a sectional, partially exploded perspective view of a conventional interior trim article.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now more particularly to the drawings, there is shown in Figure

1 an article, generally shown at 30, that is manufactured using the inventive method. The article 30 to be formed, by way of example, is a door panel. It should be appreciated by those skilled in the art that any component having a finish that includes multiple visible layers in the interior of a motor vehicle may be manufactured using the inventive method.

The article 30 includes, as integrated appliques, a first applique 32 and a second applique 34. The first applique 32 has a relatively hard surface designed to replicate a wood grain, whereas the second applique 34 is a rug section made of fabric. As shown in cross-section in Figure 1, the door panel 30 has a front surface 36 exposed to the vehicle interior and a rear surface 38, which is hidden from the vehicle interior when the door panel 30 is mounted in the vehicle (not shown).

The door panel 30 includes a reinforcing (or rigid) layer or substrate 40 having one surface defining the rear surface 38 of the door panel 30. The door panel 30 further includes another layer 42. The layer 42 is a skin 42 having front 44 and rear 46 surfaces which respectively surface towards and away from the vehicle interior when the panel 10 is mounted to the vehicle. A portion of the front surface 24 of the skin 22 is masked or covered by the appliques 32, 34. In some trim articles designed for the interior of a motor vehicle, an intermediate layer (discussed subsequently with reference to Figure 4) may extend between the substrate 40 and the skin 42. The substrate 40 should have sufficient strength and rigidity to reinforce the skin 42 and the intermediate layer for mounting into a motor vehicle sub-structure while retaining the touch and compressing feel provided to the skin 42 by the intermediate layer. The intermediate layer may be formed from a cellular polyurethane foam.

As shown in Figure 2, a first step of the inventive method is shown. This step utilizes a first mold portion 50 having a first mold surface 52. The first mold surface 52 is shaped to define a configuration that substantially complements to the desired configuration of the skin 42 and appliques 32 and 34. Optionally, the first mold surfaced 52 can be grained to define a texture that substantially complements the desired texture of the skin 42 so as to simulate leather.

Figure 2 illustrates a first step of the invention, in which the appliques 32, 34 are placed into respective recesses 54, 56 formed in the first mold surface 52. In the embodiment shown, the remainder of the first mold surface 52 has a configuration, which is substantially complementary to the exposed surface 36 of the door panel 30. The recesses 54, 56 are designed to receive the appliques 32, 34 such that the front surfaces of the appliques 32, 34 abut the first mold surface 52 and rear surfaces of the appliques 32, 34 extend away from the first mold surface 52. At this time, a vacuum may be applied at the first mold surface 52 to retain the appliques 32, 34 against first mold surface 52.

In the illustrated embodiment, the appliques 32, 34 selected are a trim section having a wood grain pattern printed on a surface thereof and a rug section made of fabric, respectively. The wood grain material can be, by way of example, a film stored as a sheet or roll that is cut into its desired pattern and size. Preferably, the selected film is somewhat rigid so that its feel is consistent with the feel of real finished wood. The thickness of the film is preferably in a range of about 0.25 mm to about 0.5 mm, more preferably about 0.25 mm to about 0.33 mm. The material from which is the film is comprised of can be, by way of example, plastics such as thermoplastics, wood, graphitic grain, metal such as chrome, and/or other materials exhibiting bright or dull mechanical finishes or other colors. The fabric used for the rug section, cloth, or cloth bolster may optionally have a foam backing. Selection of an appropriate material for forming the applique is within the purview of the skilled artisan, and will largely depend on the intended feel and appearance of the applique as well as cost considerations. It is within the scope of this invention to use applique having appearances other than that of wood or fabric. For example, the applique may be formed of a metal or brushed to have a metallic appearance, such as that of aluminum. Thermoplastics, such as ABS film are preferred for making the applique.

The next step of the method of the illustrated embodiment is depicted in Figure 3. A first layer 42 is applied to the first mold portion 50 and the appliques 32, 34. (The first layer 42 will become the skin 42, discussed above and, hence, uses the same reference character.) The first layer 42 has a front side 44 and a rear side 46. The front side 44 will become the front surface 36 of the article or, in this instance, door panel 30 upon the completion of the inventive method. The first layer 42 may be made of at least one thermoplastic material. Many other suitable materials may be used to fabricate the first layer 42. The first layer 42 is applied onto both the rear surfaces of the appliques 32, 34 and portions of the first mold surface 52 not covered by the appliques 32, 34. Preferably, the first layer 42 is preheated prior to being applied to the first mold surface 52. In addition, the first mold surface 52 may also be heated. The first layer 42 is heated to a temperature sufficient to at least soften, and preferably partially melt, the thermoplastic material. Suitable temperatures will depend on the particular film material selected. However, generally the first layer 42 should be heated to a temperature in the

range of from 80°C to about 100°C.

A vacuum is applied at the first mold surface 52 so that the first layer 42 conforms to both the rear surfaces of the appliques 32, 34 and portions of the first mold surface 52 not covered by the appliques 32, 34. Optionally, one or more gases can be blown against the rear surface of the first layer 42 facing away from the first mold surface 52 creating a positive pressure against the layer 42 to improve conformance of the first layer 42 to the first mold surface 52. Various other techniques known in the art can also be practiced, such as plug assistance, which is especially desirable where the first layer 42 is relatively thick. A fairly fast drop in vacuum pressure may be critical in accomplishing essentially 100% vacuum coverage of the film area to be drawn, with or without plug assistance.

The vacuum-formed first layer 42 is then cooled to provide the skin 42. The cooling of the first layer 42 against the appliques 32, 34 causes the appliques 32, 34 to adhere to the skin 42 and, hence, be integrated with the skin 42.

Representative thermoplastic materials include, by way of example, poly(vinyl chloride), polyolefins, ABS, PC, polyurethane, and mixtures and alloys thereof. Such backing materials are commonly commercially available in roll or sheet form. One commercial supplier to a suitable first layer 42 is ABS of Avery, Dennison, Troy, MI. The film can contain various additives, including inert fillers and the like. Generally, the skin 42 can have a thickness in a range of from 0.5 mm to 3.0 mm. The skin 42 having the appliques 32, 34 integrated thereon can then optionally be moved to a different mold having a second mold surface with a configuration which is substantially complementary to the exposed surface 36 of the article 30 so that the exposed surfaces of the appliques 32, 34 cover the second mold surface. A second cooperating mold portion 60 carrying the pre-formed substrate

40 is placed into cooperating relation with the first mold portion 50, as shown in Figure 4. The substrate 40 is formed mirror a second mold surface 62 of the second mold portion 60. Representative materials from which the substrate 40 can be fabricated include polyolefins, such as polypropylene and ethylene-propylene copolymers, thermoplastic olefins (TPOs), and thermoplastic polyolefm elastomers (TPEs). In some instances where even higher levels of performance are required, engineering thermoplastics may be selected. These include injection molding thermoplastics, such as acrylonitrile butadiene styrene (ABS), polycarbonate (PC), a PC/ABS alloy, thermoplastic polyurethane (TPU), styrene maleic anhydride (SMA), and reaction injection molded polyurethanes (RRIM). Other materials, such as metals, metal alloys, wood-fiber composites, or any combination thereof, can also be used.

The substrate 40 can optionally also include reinforcement fillers, such as glass or nanoparticles comprising platelet minerals dispersed in the desired polymer in desired ratios. The components can be blended by general techniques known to those skilled in the art. For example, the components can be blended and then melted in mixers or extruders. Additional specific methods for forming a polymer composite having dispersed therein exfoliated layered particles are disclosed in United States Patents 5,717,000, 5,747,560, 5,698,624, and WO 93/11190, each of which is hereby incorporated by reference. For additional background the following are also incorporated by reference: United States Patents. 4,739,007 and 5,652,284.

A reactive mixture 64 for forming the intermediate layer, such as a polyurethane semi-rigid cellular foam with a reticulated structure, is sprayed, poured, and/or injected into a cavity defined between portions the substrate 40 and the rear surface 46 of the skin 42. The reactive mixture 64 can be applied, for instance, by employing high pressure impingement mixing and a mix-head nozzle. The mixture 64, which is typically relatively viscous, is in a transient state of reaction during application to the cavity and begins to foam within seconds of application. A suitable temperature

range for the first 50 and second 60 mold portions at this stage is 20°C to 70°C. After

applying the reactive mixture 64 into the cavity, the mold portions 50, 60 are moved relatively towards each other to a predetermined clearance, and the mixture 64 is foamed. The resulting intermediate layer serves to unite the substrate 40 with the skin 42. Although the desired thickness of the intermediate layer generally depends upon the intended use of the article structure 30, generally the intermediate layer can have a thickness in a range of from about 1.0 mm to about 2.5 mm.

The article 30, including the united substrate 40 and skin 42 can then be removed from the mold portions 50, 60 and be subject to post-production steps, such as painting and attachment of further applique or supplemental fasteners for the article 30, if required or desired.

Various modifications and variations to the above-described embodiment fall within the scope of this invention. For example, to enhance the releasability of the skin 42 from the first mold surface 52, the first mold surface 52 can be pretreated with a suitable releasing agent. Exemplary releasing agents include, without limitation, those manufactured by ChemTrend.

According to another variant embodiment of the inventive method, a non- foamable adhesive can be selected for uniting the substrate 40 to the skin 42. Additionally, an adhesive, such as a urethane adhesive, can be applied to the rear surfaces of the appliques 32, 34 on which the first layer 42 is applied.

The invention has been described in an illustrative manner. It is to be understood that the terminology, which has been used, is intended to be in the nature of words of description rather than of limitation.

Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.

Claims

We claim:

1 . A method for manufacturing an article having multiple layers having differing surface areas using a mold assembly having a first mold portion and a second mold portion that define a mold cavity having first and second mold surfaces defining first and second surface areas, the method comprising the steps of: placing a first layer of material on the first mold portion such that the first layer of material extends along a portion of the first mold surface; applying a second layer over the first mold portion and the first layer such that the second layer extends over the first layer and all of the first mold surface; applying a pressure within the mold cavity to form the article; and applying thermal energy to the first and second layers.

2 . A method as set forth in claim 1 including the step of cooling the first and second layers after the step of applying the pressure thereto allowing the second layer to bond to the first layer.

3 . A method as set forth in claim 2 wherein the step of applying a pressure includes applying a negative pressure by creating a vacuum within the mold cavity to force the second layer to form against the first mold surface of the first mold portion.

4 . A method as set forth in claim 3 wherein the step of applying a pressure includes applying a positive pressure by inserting a gas into the mold cavity to force the second layer to form against the first mold surface of the first mold portion.

5 . A method as set forth in either of claims 3 or 4 including the step of securing the article to a substrate.

6 . A method as set forth in claim 5 wherein the step of securing the article to the substrate includes applying a third layer of material to the second layer of material after the step of cooling the first and second layers of material.

7 . A method as set forth in claim 6 including the step of heating the second layer of material before the step of applying the pressure within the mold cavity.

8 . A method for manufacturing an article having multiple layers having differing surface areas using a mold assembly having a first mold portion and a second mold portion that define a mold cavity having first and second mold surfaces defining first and second surface areas, the method comprising the steps of: positioning an applique on the first mold surface such that the applique extends along a portion of the first mold surface; applying a layer over the first mold cavity and the applique such that the layer extends over the applique and all of the first mold surface; and applying a pressure within the mold cavity to form a skin; and applying a subsfrate material into the mold cavity over the layer to form the article.

9 . A method as set forth in claim 8 including the step of adhering the substrate material to the layer prior to removing the article from the mold cavity.

10 . A method as set forth in claim 9 including the step of cooling the layer and applique before the step of applying the substrate material to the layer.

11 . A method as set forth in claim 10 wherein the step of applying a pressure includes applying a negative pressure by creating a vacuum within the mold cavity to force the second layer to form against the first mold surface of the first mold portion.

12 . A method as set forth in claim 10 wherein the step of applying a pressure includes applying a positive pressure by inserting a gas into the mold cavity to force the second layer to form against the first mold surface of the first mold portion.

13 . A method as set forth in claim 12 wherein the step of positioning the applique includes the step of aligning the applique in a recess within the first mold surface.