Comfort zone

Today’s car buyers take quality as a given. Ditto for ride, handling and braking. That’s why automakers are increasingly focusing on interior design, content and layout as brand differentiators in an industry under tremendous competitive pressure.

A panel of high-level industry executives and designers at this year’s Society of Automotive Engineers World Congress in Detroit discussed the evolution of auto interiors, and the critical role they now play in distinguishing car models and meeting consumer expectations.

Mike Warsaw, director of design for the Automotive Group of Johnson Controls, noted that consumers are demanding more up- market features that are smarter, better crafted and easier to use, but at an affordable cost.

“All around us, we see more sophisticated design and engineering showing up in more common places,” Warsaw said. “Mass market is now being redefined as high-end.”

Warsaw identified six trends he believes are shaping the direction of present and future interior design (see box). Increased consumer awareness about good design has raised the bar that designers are scrambling to clear. Engineers and manufacturers are trying to create designs that connect emotionally with car buyers, while, at the same time, meet expectations for craftsmanship, comfort, user-friendly interfaces and aesthetic sophistication.

More and more the cockpit of a person’s automobile serves as a “third”–a non-home, non-work–space. Electronics, such as Bluetooth devices, as well as satellite and video services, allow a person to stay connected with the outside world, although car manufacturers are increasingly concerned that the environment is creating a new safety hazard: Cognitive overload.

Smart products based on sensor technology, such as self-dimming mirrors and automatically adjustable seating, as well as personalized “works for me” features, including stash-and-go seating, will increasingly become standard items on many car lines, Warsaw noted. A “one-size-fits-all” or universal design has become a requirement for commercially successful automotive interiors, he added. The critical features of universal design are simple, intuitive operation, flexibility of use and tolerance for error.

ELEMENTS OF DESIGN

Amy McFarren, senior manager at J.D. Power and Associates, stressed the importance of getting the design right. “In a sense, quality has become less of a differentiator,” she said, noting the significant cost of poor design to carmakers. “If there is a quality concern, if something is broken, it can be fixed. If there is a design problem, it’s more difficult to set right.”

Both Initial Quality Surveys (IQS) and J.D. Power’s Automotive Performance Execution and Layout (APEAL) surveys have improved over the years. The IQS measures the quality performance of a vehicle in the first 90 days of ownership. The APEAL scores help determine the most important factors for consumers when purchasing vehicles. Yet, McFarren noted, good quality is no longer a guarantee of high sales if the vehicle lacks enticing design elements.

The most important design element in the interior, as measured by APEAL surveys, is seats, followed by sound systems and cockpit design. McFarren said that new technology, if too advanced or complicated, can actually have an adverse affect on a customer’s perception of quality. As an example, she noted how the Audi A6 Graphical User Interface (GUI) has brought down the interior APEAL score of the vehicle. A more conservative alternative to expensive technology or risky design layout, according to McFarren, is to incorporate a longer list of standard features in the layout of interior designs, or to continue to refine the basic features of a current design.

“Hyundai and Kia offer low cost products but they have brought up APEAL rankings with more feature packages,” she said.

Additionally, design concepts developed along the lines of traditional market segmentation may have become obsolete, according to Peter Davis, director of interior strategy and quality for General Motors.

“Customers are becoming more diverse,” he explained. “Minorities, women and people under 35 have unique needs and buying preferences.” He noted that more people today want products that compliment or express their values, personalities and lifestyles.

Customers adept at using Internet search technologies are much more informed about vehicle design and alternatives. GM is attempting to capitalize on the Internet savvy customer with its GM Fastlane blog site. The blog site has grown in popularity, Davis said, because people like the idea of having the ear of our company leaders.

Management outlook has evolved from a seeing design as a mere service to viewing it is a competitive advantage, he explained.

“We are all asking ourselves how do we develop ‘gotta have’ trucks and cars without breaking the bank? A vehicle’s interior must provide a customer with unexpected delights.”

NEW MATERIALS, TECHNOLOGY REDEFINING DESIGN

Materials suppliers and engineers are taking the lead in providing car manufacturers with new options for interior design.

GE Advanced Materials has launched what it terms, a “reinvigorated Instrument Panel program”. The initiative features several new high performance ABS and polycarbonate grades complimented by an expanded range of technical resources and support.

GE’s resin portfolio for the IP program includes the company’s recently launched series of Xtreme Cycoloy, PC/ABS resin blends. The resin family is characterized by good impact resistance, best-in-class thermal aging and hydrolytic stability, as well as low odor and emissions. Improved flow performance also offers processors the opportunity to reduce wall thickness and cycle time for specific components.

The company is also introducing an entirely new resin targeted to help in the integration of air bag cover and instrument panel design. The Lexan EXL 1414H resin is a new polycarbonate-siloxane copolymer grade with low temperature ductility down to -40C. The material is said to allow robust airbag deployment with no material fragmentation, a safety enhancement not provided by competing resins on the market, according to GE.

According to Robert Nelson, GE market director for Interiors & Structures, the IP program can help suppliers and OEMs achieve “enhanced performance and better looks for instrument panels, new innovations in integrated airbag door designs, or all of the above.”

Lanxess Lustran Ultra 4105, a PC/ABS blend, is distinguished by its combination of high impact strength and heat resistance. It is ideal for use in the manufacture of glove boxes, glove box doors, door panels, centre console components and knee bolsters on the driver’s side. Lustran Ultra 4115 has a slightly higher heat resistance than the 4105 grade, which makes it a good fit for automotive interior applications subject to high heat exposure, such as post finishers, interior door handles, air vents and defroster strips.

Seating comfort is one of the most important factors in customer perception of interior design quality. A group of researchers at Foamex International described a process to produce advanced seating material for improved passenger comfort (SAE paper 2005-01-0974). Variable pressure foaming (VPF) can be used to manufacture low density, supersoft foam with high resiliency. The foam, which is produced in a pressure-controlled, enclosed chamber, is composed of 17.5% polyurea, with a density of 1.66 lb/ft3. Water is used as the blowing agent under vacuum conditions to produce a foam with less water and less polyurea than conventional foaming techniques.

Engineers from Solvay Engineered Polymers described the development of a new polyolefin geared to meet the demands of an airbag design (SAE paper 2005-01-0978). The design incorporates the passenger side airbag into the mold-in-color instrument panel. The design results in improved aesthetics, as well as cost and weight savings. As
the airbag is hidden in the IP to provide a seamless fit, the new IP material must have both the rigidity to meet the performance requirements of the instrument panel, and low temperature ductile impact properties to meet the requirements of airbag function.

The engineered polymer is a blend consisting of elastomers dispersed in a semi- crystalline polypropylene matrix, along with various additives and fillers. The new material strikes a balance between the properties required for an instrument panel and those needed for an airbag cover. The flexural modulus of the polymer, designated EPO 3, is 1600 MPa, similar to that of a standard IP material, which in turn provides the necessary stiffness and dimensional stability. On the other hand, the impact properties at -30C of EPO 3 are similar to the ductile behavior of a conventional airbag material.

Stephen Sopher of JSP International presented details of a new class of thermoplastic foam products (SAE paper 2005-01-0976). The new polyolefin expanded-bead foam materials described by Sopher are produced using metallocene catalysts. The materials have improved mechanical and acoustic properties that make them useful in a variety of potential applications.

According to Sopher, only recently have metallocene materials been available for expanded-bead foam types of applications. The types of resins under development include expanded polypropylene (EPP) based on both random copolymer and homopolymer and expanded polyethylene (EPE) using mLDPE, mLLDPE and other blends. Tests show that these metallocene-catalyzed resins can produce a very stiff foam useful in automotive energy management applications. As well, Sopher’s team has produced a porous expanded polypropylene (PEPP) foam material with a unique, cylindrical, hollow shape. The PEPP material has significantly improved acoustic properties compared with conventional expanded polypropylene, and also molds faster.

Equipped with these and other new materials, engineers will continue to tweak automotive interiors with the goal of meeting the ever-higher expectations of the car buyer.

SIX TRENDS AFFECTING INTERIOR DESIGN*

* Consumers are more aware of good design

* Auto interior used as “third space”

* Smart products

* “Works for me” features

* Intuitive, universal design

* Car as statement

As presented by Mike Warsaw, director of design, Johnson Controls

INTERIOR DESIGN GETTING “SMARTER”

Germany-based supplier Grammer AG has developed a second-generation, crash active headrest designed to mitigate or eliminate whiplash injuries resulting from rear-end collisions. Two vehicles sold in North America, the BMW 5 and 7 Series, are equipped with Grammer’s first generation active headrest.

In the second-generation version, two coil springs push the headrest forward when triggered by a signal from the vehicle’s control unit; a magnetic switch triggers a U-shaped locking spring. The activation time following a rear-end collision is 50 to 55 ms, faster than a typical airbag deployment of 120 ms.

The second-generation headrest is comprised of two coil springs, a plastic headrest housing, an electromagnetic activation plate and wiring. The main difference between the first- and second-generation product is that the first-generation model uses a pyrotechnic method of deployment.

L&P Automotive Group (Lakeshore, ON) is developing seats equipped with massage technology. Several OEMs have chosen the technology for use on selected 2006-2007 luxury models. A lumber “support basket” made of nylon and other materials is incorporated into the seating. The massage cycle is activated by a switch, producing a dynamic, four-way massaging action designed specifically for driving conditions.

Grammer Automotive has been selected by Jaguar to supply headrests with integrated video displays for the company’s Jaguar XJ. The video unit consists of two high-resolution, 6.5 inch LCD monitors that are integrated into the rear of the front-seat headrests. The location is more ergonomically favorable than overhead displays, which require passengers to look up. The two headrest monitors may be operated independently. The multimedia control panel allows playback of videos, CDs and DVDs, plus video games and laptops can also be connected. Sound is transmitted via headphones.