Trim component for a vehicle interior

A trim component for a vehicle interior includes first and second skin layers, a core layer sandwiched between the first and second skin layers with the core layer having first and second sides, a first thermoplastic adhesive material including a polyamide disposed between the first skin layer and the core layer to adhere the first skin layer to the first side of the core layer, and a second thermoplastic adhesive material including a polyamide disposed between the second skin layer and the core layer to adhere the second skin layer to the second side of the core layer.

FIELD OF THE DISCLOSURE

The present disclosure relates generally to a trim component for a vehicle interior.

BACKGROUND

Load floors are often disposed within a cargo, luggage, or other similar area within a vehicle. The load floor is typically constructed from lightweight materials, and should be strong enough to support a load. However, many load floors still tend to break or crack when exposed to heavy loads. Accordingly, there remains an opportunity to provide a trim component for a cargo area of a vehicle, such as a load floor, that is lightweight and can withstand heavy loads without breaking or cracking.

SUMMARY

An embodiment of a trim component for a vehicle interior comprises a first skin layer, a second skin layer, a core layer sandwiched between the first and second skin layers with the core layer having first and second sides, a first thermoplastic adhesive material including a polyamide disposed between the first skin layer and the core layer to adhere the first skin layer to the first side of the core layer, and a second thermoplastic adhesive material including a polyamide disposed between the second skin layer and the core layer to adhere the second skin layer to the second side of the core layer.

Another embodiment of a trim component for a vehicle interior comprises a first skin layer formed from a blend of glass fibers and a thermoplastic material, a second skin layer formed from a blend of glass fibers and a thermoplastic material, a core layer sandwiched between the first and second skin layers with the core layer having a honeycomb structure with first and second sides, a first thermoplastic adhesive material including a polyamide disposed between the first skin layer and the core layer to adhere the first skin layer to the first side of the core layer, and a second thermoplastic adhesive material including a polyamide disposed between the second skin layer and the core layer to adhere the second skin layer to the second side of the core layer.

DETAILED DESCRIPTION

Referring now to the figures, wherein like numerals indicate corresponding parts throughout the several views, embodiments of a trim component100are shown in the figures and are described in detail below. In the illustrated embodiments, the trim component100is a load bearing surface, such as a load floor for a vehicle interior that is capable of bearing a load without damaging the structure of the component. For example,FIG. 1illustrates a portion of a vehicle10having a cargo area12, and the trim component100is disposed within and forms a load floor for the cargo area12of the vehicle10. While the trim component100is used in the cargo area12of a suitable vehicle, such as a van, truck, sport utility vehicle, and/or the like, it is to be appreciated that the trim component100can be used anywhere within the vehicle interior. It is further to be understood that the trim component100can be used in any type of vehicle, not limited to automobiles. For example, the trim component100could be used in airplanes, boats, trains, trailers, buses, etc.

An embodiment of the trim component100is described below with reference toFIGS. 2-4. The trim component100is a sandwich composite including a first skin layer102, a second skin layer104, and a core layer106sandwiched between the first102and second104skin layers. The trim component100further includes a first thermoplastic adhesive material108disposed between the first skin layer102and the core layer106, and a second thermoplastic adhesive material110disposed between the second skin layer104and the core layer106.

The first102and second104skin layers are generally lightweight, thin layers of material disposed on opposing first112and second114sides of the core layer106. Each of the first102and second104skin layers is formed from a material chosen from glass, a glass fiber composite material, a carbon fiber-reinforced polymer, a thermoplastic polymer, a thermoset polymer, and combinations thereof. In one particular embodiment, each of the first102and second104skin layers are formed from a blend of glass fibers and a thermoplastic material, such as polypropylene. In another particular embodiment, each of the first102and second104skin layers are formed from glass fiber-reinforced polypropylene. Non-limiting examples of suitable materials for the first102and second104skin layers include SymaLITE®, a glass-reinforced thermoplastic composite material available from Quadrant Engineering Plastic Products, Inc. (Reading, Pa.) and SuperLite®, a thermoformable composite of plastic resin and long chopped fibers available from Hanwha Azdel Inc. (Forest, Va.). Typically, the first102and second104skin layers are formed from the same material, such as the glass fiber-reinforced polypropylene. Alternatively, the first102and second104skin layers could be formed from different materials or combinations of different materials.

In an embodiment, the weight of each of the first102and second104skin layers is from about 500 to about 2,000 gsm (grams per square meter). In another embodiment, the weight of each of the first102and second104skin layers is from about 500 to 1,200 gsm. It is to be appreciated that the weight of the first102and second104skin layers is typically based, at least in part, on load specifications of the vehicle12. To this end, the weight of each of the first102and second104skin layers may be lower for smaller vehicles (such as a small sport utility vehicle) and may be higher for larger vehicles (such as a van). In another embodiment, the weight of the first skin layer102may be different from the weight of the second skin layer104. In an example, the weight of the first skin layer102(which would be the top layer of the trim component100) may be 25 to 30% less than the weight of the second skin layer104(which would be the bottom layer of the trim component100). In another example, the weight of the first skin layer102(top layer) may be from 500 to 700 gsm, and the weight of the second skin layer104(bottom layer) may be from 900 to 1,200 gsm.

As previously mentioned, the core layer106is sandwiched between the first102and second104skin layers. More particularly, the core layer106has opposed first114and second116sides, and the first skin layer102is disposed on the first side114of the core layer106and the second skin layer104is disposed on the second side116of the core layer106. The core layer106is a generally thick layer chosen from a suitable lightweight material having relative low strength such that the core layer106has low density and a high bending stiffness. As best shown inFIG. 3, the core layer106has a honeycomb structure. For example, the honeycomb structure may have an array of hollow cells formed between thin vertical material walls. The cells are typically columnar and hexagonal in configuration, however other configurations of the cells are also contemplated. In addition, the honeycomb structure is an unfilled honeycomb structure. Alternatively, the honeycomb structure could be filled; e.g., the columns of the honeycomb structure could be filled with one or more foams for added strength. In one embodiment, the core layer106has a paper-based honeycomb structure, having a paper weight of from 23 to 29 lbs/ft3(pounds per cubic feet), a thickness of about 1 to 4 mm, and a honeycomb cell diameter of from 6 to 12 mm (millimeters). In a non-limiting example, the core layer106is formed from an Axxor endless honeycomb core, a paper-based honeycomb structure available from Axxor BV (The Netherlands). Alternatively, the core layer106could have a honeycomb structure formed from open-cell-structured foams, closed-cell-structured foams, balsa wood, syntactic foams, metal, and/or combinations thereof.

The first thermoplastic adhesive material108is disposed between the first skin layer102and the first side112of the core layer106, and the second thermoplastic adhesive material110is disposed between the second skin layer104and the second side114of the core layer106. The first thermoplastic adhesive material108operates to form suitably strong adhesive bond between the first skin layer102and the core layer106, and the second thermoplastic adhesive material110operates to form a suitably strong adhesive bond between the second skin layer104and the core layer106. In an embodiment, the first108and second110adhesive materials are chosen from a thermoplastic adhesive material including a polyamide. It was found that the thermoplastic adhesive including the polyamide forms a suitably strong adhesive bond between the skin layer102,104formed from a blend of glass fibers and polypropylene (such as glass fiber-reinforced polypropylene) and the core layer106. A non-limiting example of a suitable adhesive material includes APT 9B9B, a thermoplastic adhesive material including a polyamide available from Advance Packaging Technologies (Waterford, Mich.).

In an embodiment, the thermoplastic adhesive materials108,110are activated by applying heat. In an example, the thermoplastic adhesive material including the polyamide is activated when heated to a temperature of at least 290° F. (at least 143° C.). When activated, the thermoplastic adhesive material108forms an adhesive film between the first skin layer102and the core layer106, which forms a suitable surface-area bond between the first skin layer102and the core layer106. Similarly, when activated, the thermoplastic adhesive material110forms an adhesive film between the second skin layer104and the core layer106, which forms a suitable surface-area bond between the second skin layer104and the core layer106. In an embodiment, the film formed by each of the first108and second110adhesive materials has a weight of from 40 to 110 gsm.

The trim component100may be formed utilizing a molding/layering process. This process involves applying the first thermoplastic adhesive material108to the first side112of the core layer106, and disposing a sheet of the first skin layer102over the first thermoplastic adhesive material108on the first side112of the core layer106. The process further involves applying the second thermoplastic adhesive material110to the second side114of the core layer106, and disposing a sheet of the second skin layer104over the second thermoplastic adhesive material110on the second side114of the core layer106. The skin layer102, the first adhesive material108, the core layer106, the second adhesive layer110, and the second skin layer104are laminated together to form a sandwich composite. The composite is placed in an oven and heated at least to the activation temperature of the adhesive materials108,110. In an embodiment, the oven is heated to an activation temperature of at least 290° F. When activated, the adhesive material108,110operates to form an adhesive surface-area bond between the skin layers102,104and the core layer106.

After heating, the composite is placed into a molding tool (operated at a lower temperature, such as at or near 60° F.) and the composite is molded into a desired configuration under pressure. During a compression stage of the molding process, the skin layers102,104are pressed into the individual cores of the honeycomb structure of the core layer106, and the underlying adhesive material108,110causes additional bonding of the skin layers102,104to the core layer106within the individual cores of the core layer106. To this end, it has been found that a suitably strong bond between the skin layers102,104and the core layer106can be formed with the specific of the materials selected for the skin layers102,104, the core layer106, and the adhesive materials108,110. It has also been found that a superior bond between the skin layers102,104and the core layer106can be formed during the compression stage of the molding process when the skin layers102,104are pressed into the individual cores of the core layer106.

In an embodiment, and as shown inFIG. 4, the periphery116of the trim component100may be pinched to form a seal. Pinching may be accomplished, for example, during the molding process described above. When pinched, the skin layer102(with the adhesive material108), contacts the other skin layer104(with the adhesive110) and forms a seal along the periphery116of the trim component100. By forming a seal, the skin layers102,104encapsulate the core layer106to protect the core layer106, for example, from degradation.

In another embodiment, and as shown inFIG. 5, the trim component100may further include cover layers118,120that may be used for decorative purposes. The cover layers118,120may be disposed on and adhered to the skin layers102,104, respectively, utilizing a suitable adhesive (not illustrated in the drawings), non-limiting examples of which include heat-activated polypropylene adhesives or other thermoplastic perforated or solid film adhesives.

The embodiments and examples of the trim component100described in detail above is desirably lightweight and has a suitable stiffness for resistance to deflection and to satisfy load bearing requirements. Additionally, the trim component is desirably strong due, at least in part, to the strong and superior bond formed between the skin layers102,104and the core layer106. As mentioned above, the strong and superior bond is formed by the specific combination of materials of the skin layers102,104(namely, a glass fiber-reinforced polypropylene), a paper-based honeycomb core layer106, and the thermoplastic adhesive material108,110including a polyamide. The strong and superior bond may also be formed by the specific combination of materials of the skin layers102,104, the core layer106, and the adhesive materials108,110, in combination with compression of the layers102,104,106during the molding process.

The trim component100of the present disclosure is further illustrated in the Examples set forth below. It is to be understood that the Examples are provided for illustrative purposes and are not to be construed as limiting the scope of the present disclosure.

EXAMPLES

Three composite samples were prepared, and each of the samples were tested for bond strength utilizing the ASTM C297-15 test method. The first sample is identified by PA-A, which is a sandwich composite including a paper-based honeycomb core sandwiched between Azdel SuperLite® skin layers utilizing APT 9B9B, which is a thermoplastic adhesive material including a polyamide. The second sample is identified by PA-Q, which is a sandwich composite including a paper-based honeycomb core sandwiched between Quadrant SymaLITE® skin layers utilizing the APT 9B9B adhesive. The third sample is identified by PP-A, which is a sandwich composite including a paper-based honeycomb core sandwiched between Azdel SuperLite® skin layers utilizing an adhesive material including polypropylene.

The three samples were tested for bond strength utilizing the ASTM C297-15 test method (2015). In particular, this test method is designed to determine the flatwise tensile strength of the core, the core-to-facing bond, or the facing of an assembled sandwich panel. Utilizing a testing machine, the test method consists of subjecting the sandwich composite samples to a uniaxial tensile force normal to the plane of the sample. The force is transmitted to the sandwich composite sample through thick loading blocks, which are bonded to the sandwich composite facings (or skin layers) or directly to the core.

Three specimens of each sample were tested, and a maximum load (N) was determined for each of the specimens at the point when breakage occurred in the adhesive layer at the skin-core layer interface. The maximum load for each of the specimens for each sample tested is set forth in Tables 1-3 below.

TABLE 1Bond Strength Test Results for Sample PA-ASpecimenMaximum Load (N)Break Mode11153Adhesion of Core-Facing Adhesive21142Adhesion of Core-Facing Adhesive31153Adhesion of Core-Facing AdhesiveMean1149

TABLE 2Bond Strength Test Results for Sample PA-QSpecimenMaximum Load (N)Break Mode11114Adhesion of Core-Facing Adhesive21087Adhesion of Core-Facing Adhesive31336Adhesion of Core-Facing AdhesiveMean1179

TABLE 3Bond Strength Test Results for Sample PP-ASpecimenMaximum Load (N)Break Mode190Adhesion of Core-Facing Adhesive2104Adhesion of Core-Facing Adhesive360Adhesion of Core-Facing AdhesiveMean85

As shown in Tables 1-3 above, the sandwich composite samples utilizing the thermoplastic adhesive material with a polyamide could withstand much higher loads (N) compared to the sandwich composite sample utilizing the adhesive material including polypropylene. These results indicate superior bond strength between the skin layers and the core layer of the composite samples utilizing the thermoplastic adhesive material including the polyamide, compared to the composite sample utilizing the adhesive material including polypropylene.