Soft tops free up designers while offering same driving comfort as hard tops

New technology for retractable roofs and soft tops is delivering the same – or better – acoustic and weather protection as standard hard tops. 

Earlier this year it was announced that the all-new 2015 Mustang convertible will be topped with Haartz’s Twillfast® RPC top. The Haartz Corporation has supplied topping material for the Mustang since 1983. The Mustang used a Double Texture PVC topping material until the 1997 model year, when it switched to a Single Texture PVC. In the 2006 model year, Ford began using the Haartz Twillfast RPC topping material. Twillfast RPC is an acoustically enhanced three-ply composite made of an acrylic twill weave outer fabric, a rubber inner layer and a polyester lining fabric. This unique material composition is designed to endure all temperature variations and weather conditions and allows drivers to enjoy a truly all-season vehicle. 

 

“The Twillfast RPC material is a great fit for sports cars like the Mustang because of its acoustic optimization and luxurious look,” said John Fox, president of Haartz. “We are honored to have the opportunity to work with Ford on this monumental vehicle.” The topping material for the Mustang will be produced in Haartz’ Acton, Mass. facility. 

 

Haartz says that its topping materials can be customized to meet OEM specifications and design targets while maintaining superior acoustical and NVH (noise, vibration and harshness) performance and optimized trunk space when the top is down. The range was showcased at the April Society of Automotive Engineers Automotive World Congress at Cobo Center, Detroit. Haartz also supported the Ride & Drive event with two iconic vehicles exhibiting Haartz advanced technologies for soft tops. 

 

Haartz says its convertible toppings are engineered to dispel the misconceptions of soft top convertibles. Combining the latest in textile and plastics technology, Haartz materials offer benefits on par with both coupes and retractable hard tops including allseason driving and superior acoustical and NVH (noise, vibration and harshness) performance. Featured in the Ride & Drive event were the the Audi A5 Cabriolet, which is fitted with the company’s Sonnenland® A5.B/DS acoustic topping; and the Jeep Wrangler which is covered by Haartz’s Twillfast RPC roof product. 

 

The interior trim section of the exhibition showcased the Soft-Tek line of TPO-skinned soft-touch moldable laminates, Deploy™ TPO skins for non-scored Instrument Panels, and Alura® & Pellano™ artificial leather products. All are designed to offer the OE and Tier 1 engineers and designers the optimum level of flexibility for the vehicle cabins of the future. Pellano has an inherent supple nature that will follow the contour of any surface. A shear touch of the surface against your skin will evoke a feeling of serene comfort and knowledge that the environment has been considered in every step of its processing, according to Haartz. 

 

The Massachusetts-based Haartz, has additional manufacturing in Mannheim, Germany and a facility in Pune, India will soon be operational. Beyond these manufacturing locations, Haartz maintains sales offices in Detroit, Munich, Tokyo, Delhi, India and Chongqing, China. Employing over 400 people worldwide, Haartz has been a trusted automotive supplier since 1907, and continues to be privately owned and operated by the Haartz family. 

 

In April this year, the Haartz Advanced Development Team were given the challenge to create a product that could release an airbag through a bilaminate skin without any pre-scoring. Their endeavors resulted in Deploy, a range of instrument panel surface materials designed specifically for processing in a negative vacuum form tool (NVF). The need for pre-scoring (which can lead to “A” surface read through after heat ageing) is no longer necessary. The Haartz team’s success developed a balance between both the function and aesthetic requirements of the consumer, says the company. 

 

Williams: The opportunity to highlight our latest technologies to the automotive engineering community. Of specific note were the Ride & Drive vehicles exhibiting our acoustically-enhanced and design-themed topping capabilities. 

 

Williams: While soft-tops remain a small portion of the global automotive marketplace, they are increasingly becoming an option for vehicle customization. 

 

 

• More design enhancements expressed in topping fabrics such as the cloth topping addition to the Jeep Wrangler, Jacquard design on the Citroen DS3 and HT toppings on vehicles such as the BMW 1-Series, Mini Cooper, and Smart Four Two 

• A broader range of roof types with open-air driving, including the semi-cabrio, such as Smart FourTwo and Fiat 500C; folding roof like the Renault Twingo, Citroen C1, Peugeot 107, and Toyota Aygo, and targa top on the Porsche 911 

• A reversion to soft-tops on models formerly offered as retractable hard tops due to the soft-tops’ ability to offer an open-air solution at a more reasonable engineering and manufacturing cost without compromise of the trunk space in the vehicle.

 

Williams: The reduction of vehicle interior noise levels has been a constant push by the OEMs for several years now. Haartz has responded with engineered solutions via our textile and rubber compounding capabilities to reduce sound transmission of our material by >=3dB-A across our Sonnenland® and Twillfast® product lines. This, in conjunction with the additional insulating layers introduced by the OEs/Tier 1s, has resulted in soft-tops having comparable, if not better, acoustic performance than the same model in a coupe. 

 

Williams: In our cloth topping products we offer our Sonnenland Jacquard product where contrasting yarn colors and the weave patterning provide for nearly limitless design opportunities. Most efforts are focused on implementing specific brand- or model-specific designs into the roof like the DS3 logo from Citroen’s popular line of sport hatchbacks. 

 

Williams: Of specific note are our Deploy™ and Pellano™ lines. Deploy is a TPO-foam bilaminate constructions for in-mold grain Instrument Panel (IP) applications. A specific advantage of Deploy is to alleviate the need for scoring the backside of the IP in the airbag deployment area. This allows OE designers to have a clean look on the A-class surface of the IP that enhances the aesthetic of the cockpit. With Pellano, Haartz has advanced the technology of synthetic leathers by offering a material with exceptional haptics and tailorability in a construction as minimal of an environmental impact as possible. 

 

Williams: Beyond Sonnenland Jacquard, Haartz has enhanced the design capabilities of topping fabrics with offerings in our Sonnenland and Twillfast ranges with metallic and colorshifting appearances. Respectively known as HT (high-tech) and Panama toppings, these offer the OE designers even more opportunity to express the unique design and look of the cabrio through the topcover. A recent introduction is the striped toppings of the Fiat 500C Gucci Edition and Corvette C6 60th Anniversary Edition. In both cases Haartz was able to match the color and maintain the dimensional tolerances the OEs provided while exhibiting a unique design feature through the soft-top