, Building/Construction, Gardening/Agricultual and Appliance/Electrical-COMPONENT Applications.
Although most SMC and BMC in North America and Europe are generally purchased in standard formulations from compounders, BMC does offer processors that have the right equipment the opportunity to compound at the press shortly before molding — an option used in China. ILC gives processors a broader opportunity to tailor reinforcements, fillers and other additives to achieve the properties required for a given application. For high-volume applications, this can be less costly than purchasing precompounded materials. The ability to adjust the formulation on the fly also saves time and grants more control to the processor. These attributes make it easier for molders to create custom compounds for short production runs and allows them to modify properties more quickly during preliminary part development and/or when field data for commercial products indicate that properties need adjustment.
Now, thanks to the work of a European consortium, it is possible to combine the lower cost and formulation flexibility of BMC with the higher mechanical performance of SMC in a hybrid process called Direct-SMC (D-SMC, also called direct-strand molding compound). Developed by research house Fraunhofer Institute for Chemical Technology (Fraunhofer ICT, Pfinztal, Germany), machinery OEM Dieffenbacher GmbH + Co. KG (Eppingen, Germany) and resin supplier DSM Composite Resins AG (Schaffhausen, Switzerland), the process eliminates the need for the several-day maturation period required with conventional SMC and reduces production delays. With D-SMC, the commonly lengthy interval between compounding raw ingredients and demolding finished parts can be shortened to minutes.
More challenging to the achieve with conventional smc. "
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-IN-TIME & RSQUO; SMC Process Was How to Dose and Compound the Material Accurately and Consistently. ""
; from compounding through molding & mdash; can take as little as 15 minutes.
FPC@Western, Which is set to open in the third quars of 2012 for North American Composits Development.
“The main idea of ??direct technology for thermoset compression-molded composite parts was to establish a continuous, integrated process chain with seamless process control, from raw material to ready-molded parts,” recalls Dieffenbacher’s technical director, Matthias Graf. “From the fiber-reinforced thermoplastics side, we have seen the shift from precompounded pellets and GMT sheet stock to a direct processing technology. Since SMC can be considered to be a thermoset type of LFT-D, the idea was to follow a similar process.” Although Dieffenbacher is one of the inventors of D-LFT and sells ILC units that are coupled to its large compression presses to compound and mold D-LFT parts sequentially, Graf shares the credit for D-SMC’s success, thus far, with its consortium partners. “We formed a team representing the best in each field of machinery, resin chemistry and research to get D-SMC to work,” he points out. “No single company could have achieved this alone.”
Capable of a high degree of automation, the continuous D-SMC process is fulfilling its promise. It provides full line control, visualization and documentation from compounding through molding. Moreover, it saves considerable energy and costs by eliminating previous transport and storage steps; it provides reproducible fiber impregnation and consistent, Class-A quality; and it allows individual recipes to be optimized for all ingredients. Notably, D-SMC also provides opportunities to increase fiber-volume fractions for more demanding applications. Given these benefits, D-SMC offers not only a greater degree of formulation freedom for compression-molded BMC molding manufacturer composites but also provides opportunities for SMC molders to fight for market share lost to D-LFT composites during the past decade.