CW Blog

The March GBI: Composites Index moved lower as a significant slowing of new orders activity combined with an increase in production activity resulted in the sharpest contraction in backlogs since June 2016. The latest reading of 52.6 is 13.0 percent lower compared to the same month one year ago when the Composites Index was only one month away from reaching its all-time high in April 2018. Gardner Intelligence’s review of the underlying data indicates that the Index was sustained by production, supplier deliveries, employment and new orders. The Index – calculated as an average — was pulled lower by exports and backlogs, both of which contracted during the month.

February’s surprise expansion in new orders activity did not carry into March, as the latest reading for new orders fell nearly five points. Between January and March, the new orders reading experienced a net 2.5-point increase. Exports registered a fourth month of either contracting or flat activity, which further weakened order activity. The recent activity in new orders and exports combined with a small increase in production activity resulted in backlogs contracting at the steepest rate in more than two years.

A couple of years ago, Solvay Composite Materials (Alpharetta, Ga., U.S.) introduced a new carbon fiber-reinforced prepreg, SolvaLite 730, specifically developed for higher-volume automotive production. The product is said to offer shorter cycle times, less scrap during shutdown, zero tack for better automated handling, and lower labor, thereby reducing manufacturing costs — a desirable combination for automakers and suppliers, especially as carbon fiber composites expand into higher-volume vehicle platforms. Solvay was vague at the time of its introduction about what this material actually was, but more details have emerged; what we now know about SolvaLite 730 follows.

First, the matrix resin is not epoxy. Rather, it is based on a “toughened, highly engineered” vinyl hybrid resin system. It is designed to be styrene-free and very low in volatile organic compounds (VOCs) — something easy to do with epoxies but a real challenge with traditional unsaturated chemistries such as vinyl esters and unsaturated polyesters. Follow-on benefits are that this prepreg does not require freezer storage and temperature-controlled transportation (currently costly and rate-limiting steps), but rather can be kept at room temperature. "We see the primary benefit of not requiring frozen storage to be that it hugely simplifies inventory control," explains Dr. Stephen Jones, Solvay's materials scientist-composite materials, who worked on formulation of the final products. "Material can be stored, and plies, kits and preforms can be produced and managed, without the need for freezing and defrosting, which take space, time and cost money (both capital and operating expenses). Also, they add risks to production that are absent with metals." Another benefit is that at shift’s end, unused material need not be discarded, but rather can be covered and returned to a shelf for use at a later stage. The material has a long outlife (minimum 6 months), yet snap cures in less than 60 seconds at 170°C, making it fast enough to supply 150,000 parts/year from a single toolset. (In thin cross-sections, the material is said to cure in 45 seconds at 170°).

As carbon fiber-reinforced polymer (CFRP) and ceramic matrix composite (CMC) materials proliferate in aircraft engines, space components and hypersonic applications, machining becomes an issue where precision and efficiency can alter program outcomes. Trying to machine high-reliability and high-accuracy features into CFRPs and CMCs can be challenging due to their hardness and abrasiveness, resulting in slow machining rates, undesirable effects on material properties, inability to meet parts specifications and high operational costs, including recurring tool replacement.

To meet this challenge, a range of laser technologies have been developed for machining such advanced composites. While lasers offer the potential for increased efficiency and elimination of recurring tool costs, the heat generated dissipates into the material, creating potential for microcracking and material change. Lasers also cut at the focal point of the light beam, resulting in V-shaped cuts that can be problematic for precise tolerances.

“Too often, designs are thrown over the wall to manufacturing.” Neatly summarizing a common yet undesirable state of affairs, Robert Yancey, director of manufacturing and production industry strategy and business development at Autodesk (San Rafael, Calif., U.S.), goes on to talk about the “convergence of design and manufacturing” to which his company is devoting significant resources. Such efforts are a crucial element in the build-out of the digital thread, which is meant to provide the communications framework that ultimately will connect functions throughout a product’s lifecycle.

Variously called “smart manufacturing,” the “Industrial Internet of Things (IIoT),” or “Industry 4.0” (alternately, “Industrie 4.0”), the digitalization of today’s manufacturing operations is well underway in many sectors. In some instances, like the fully automated Siemens (Munich, Germany) Simatic programmable logic controller (PLC) factory in Amberg, Germany, or the Composites Technology Center (CTC, Stade, Germany; a subsidiary of Airbus Operations GmbH), full digitalization has been deliberately implemented from near-clean sheet design. Much more commonly, though, manufacturers must transition incrementally from existing operations to the fully digital future.

It’s an unfortunate fact of modern life that many school districts across the U.S. feel the need to protect themselves from violent intruders. In addition to training, schools have begun to implement a huge array of smart technology and materials to fight security threats, which the Washington Post (Nov. 13, 2018 issue) has estimated could represent a $2.7 billion market.

One composites manufacturer is a part of this growing market. Strongwell’s (Bristol, Va., U.S.) pultruded HS Armor panels, which were first produced as a military product application, are designed for ballistics resistance. The monolithic (non-cored) panels are pultruded using multiple layers of woven mat — with the number of layers dependent on the performance requirements — wet out with a proprietary (non-epoxy) resin matrix and cured in a controlled cycle. Panels are typically 4 ft. wide, in lengths ranging from 8 to 12 ft. When struck by a bullet or other projectile, HS Armor panels delaminate in a way that absorbs the energy while stopping the projectile. They have been independently tested to Underwriter’s Laboratory (UL) 752 (Levels 1 through 8) and National Institute of Justice (NIJ) Ballistics Specifications (Levels 1, 2A, 2 and 3A) and meet the UL 94 V-0 flammability rating.