2017 Nissan Maxima Quarter Panel Molding

The 2017 Nissan Maxima, a vehicle celebrated for its blend of sporty handling and near-luxury comfort, relies on a combination of engineering and design to achieve its aesthetic and functional goals. One often overlooked component that contributes significantly to both is the quarter panel molding. This seemingly simple piece plays a crucial role in protecting the vehicle's body and enhancing its visual appeal. Let's delve into the technical details of the 2017 Nissan Maxima's quarter panel molding, examining its materials, construction, installation, and the underlying engineering considerations.

Material Selection and Properties

The selection of materials for the quarter panel molding is paramount. It must withstand a variety of environmental conditions, including extreme temperatures, UV radiation, road debris, and potential impacts. For the 2017 Maxima, manufacturers typically employ a high-quality thermoplastic material, often a blend of Polypropylene (PP) and Ethylene Propylene Diene Monomer (EPDM) rubber.

Polypropylene (PP): PP is chosen for its excellent chemical resistance, high tensile strength, and relatively low cost. It provides the molding with structural rigidity and the ability to maintain its shape over time. However, PP alone is brittle and susceptible to cracking, especially in cold temperatures.
Ethylene Propylene Diene Monomer (EPDM) Rubber: EPDM is a synthetic rubber known for its exceptional resistance to weathering, ozone, and heat. The addition of EPDM to the PP blend improves the molding's impact resistance and flexibility, preventing cracks and breaks under stress. This is crucial as the quarter panel area is frequently subjected to minor impacts from other car doors or shopping carts.

The specific ratio of PP to EPDM, as well as the inclusion of any fillers or additives, is a closely guarded trade secret among molding manufacturers. These formulations are carefully optimized to achieve the best balance of strength, flexibility, and weather resistance. Furthermore, UV stabilizers are commonly added to the compound to prevent degradation and fading of the molding's color due to prolonged exposure to sunlight.

Manufacturing Process: Injection Molding

The quarter panel molding is typically manufactured using injection molding, a highly efficient and cost-effective process for producing large quantities of plastic parts. Here's a simplified breakdown of the injection molding process:

Material Preparation: The PP/EPDM blend, along with any additives, is fed into a hopper. This material is usually in the form of pellets.
Melting: The pellets are conveyed through a heated barrel by a rotating screw. The friction generated by the screw, combined with the heat from the barrel, melts the plastic into a viscous liquid.
Injection: The molten plastic is injected under high pressure into a precision-engineered mold cavity. The mold cavity is a negative impression of the desired molding shape.
Cooling: The mold is cooled using a network of water channels. As the plastic cools, it solidifies into the shape of the mold cavity.
Ejection: Once the plastic has sufficiently cooled and solidified, the mold opens, and the finished molding is ejected.
Finishing: The molding may undergo finishing processes such as trimming any excess material (flash) and applying a protective coating or paint.

The precision of the mold is critical to the final product's quality. The mold must accurately reproduce the complex curves and features of the quarter panel molding, ensuring a perfect fit against the vehicle's body. The cooling process is also crucial, as uneven cooling can lead to warping or distortion of the molding. Computer-Aided Engineering (CAE) tools are often used to simulate the injection molding process and optimize the mold design to minimize these issues.

Design Considerations and Functionality

The design of the quarter panel molding is driven by several key considerations:

Aesthetics: The molding must seamlessly integrate with the overall design of the vehicle. This includes matching the color, texture, and profile of the surrounding body panels.
Protection: The primary function of the molding is to protect the quarter panel from minor impacts, scratches, and road debris. Its shape and placement are carefully chosen to deflect potential damage.
Aerodynamics: While the quarter panel molding is not a major contributor to the vehicle's overall aerodynamics, its design must not create excessive drag or wind noise.
Attachment Method: The molding must be securely attached to the vehicle's body, while also being relatively easy to remove and replace for maintenance or repairs.

The molding typically features a complex cross-sectional profile, often incorporating a slight lip or flange that overlaps the edge of the quarter panel. This lip helps to deflect impacts and prevent scratches from reaching the painted surface. The surface texture of the molding is also carefully chosen. A slightly textured surface is less likely to show scratches and swirls than a smooth, glossy surface.

Attachment Mechanisms and Installation

The 2017 Nissan Maxima quarter panel molding uses a combination of mechanical fasteners and adhesive to ensure secure attachment. Here's a common attachment strategy:

Clips: Plastic clips are strategically positioned along the backside of the molding. These clips are designed to snap into corresponding holes in the quarter panel. The clips provide a strong mechanical connection and help to distribute the load evenly across the molding.
Adhesive Tape: Double-sided adhesive tape, typically made from acrylic foam, is applied to the backside of the molding. This tape provides an additional layer of adhesion and helps to seal the molding against the body, preventing water and debris from entering the gap between the molding and the quarter panel.

Installation of the quarter panel molding requires careful alignment and pressure. The installer must ensure that the clips are properly engaged in the corresponding holes and that the adhesive tape is making full contact with the body. A roller tool is often used to apply uniform pressure along the length of the molding to ensure optimal adhesion. Proper surface preparation is also crucial. The area of the quarter panel where the adhesive tape will be applied must be clean, dry, and free of any wax or grease.

Removal and Replacement Considerations

Removing a damaged quarter panel molding requires caution to avoid damaging the surrounding body panels. Here are some key considerations:

Heat: Applying heat to the molding with a heat gun or hair dryer can soften the adhesive tape and make removal easier. However, care must be taken not to overheat the plastic molding, as this can cause it to deform or melt.
Plastic Trim Tools: Specialized plastic trim tools are designed to pry the molding away from the body without scratching the paint. These tools have a wide, flat blade that can be inserted between the molding and the quarter panel to release the clips and adhesive tape.
Adhesive Removal: After the molding has been removed, any remaining adhesive residue must be carefully removed from the quarter panel using a solvent-based adhesive remover. The area should then be cleaned and prepped before installing the new molding.

When replacing a quarter panel molding, it's essential to use a genuine Nissan replacement part or a high-quality aftermarket equivalent. Inferior moldings may not fit properly, may be made from substandard materials, and may not provide adequate protection. Furthermore, when installing a new molding, it's critical to follow the manufacturer's instructions carefully to ensure proper alignment and adhesion.

Conclusion

The quarter panel molding on the 2017 Nissan Maxima, though seemingly a minor component, represents a carefully engineered solution to protect the vehicle's body and enhance its aesthetics. The selection of materials, the precision of the manufacturing process, and the thoughtful design of the attachment mechanisms all contribute to its overall effectiveness. By understanding the technical details of this component, we gain a deeper appreciation for the engineering that goes into even the smallest parts of a modern automobile. The next time you see a Maxima, take a moment to appreciate the humble, yet crucial, quarter panel molding – a testament to the power of thoughtful design and material science. It's a simple part, executed well. And that is the essence of good engineering.