DD|Compound (Ibbenbüren, Germany) displayed its latest resin infusion aid, the MTI valve. MTI addresses a common problem during the infusion process: Prior to infusion, the resin is at ambient pressure. When it enters the mold cavity during infusion, the vacuum compaction is released, resulting in a gradient of higher thickness and lower fiber volume across the part from resin inlet to vacuum outlet. The company pointed out that The Boeing Co. (Chicago, Ill.) developed its Controlled Atmospheric Pressure Resin Infusion (CAPRI) process to address this problem, using an additional vacuum pump to reduce the pressure in the resin feed tank and, thus, reduce the pressure differential. The MTI valve reportedly accomplishes the same goal by simulating a calculated delta in pressure — e.g., 150 mbar for 55 percent fiber volume fraction. The valve automatically shuts off when the pressure equalizes, based on these calculations.