SMC Flow Simulation Is More User-Friendly
An updated version of its “Cadpress” SMC compression molding simulation program for the PC has improved graphics and information displays, says the developer, The Madison Group: PPRC, Madison, Wis. Available for Windows 95, 98, and NT, the new version simulates mold filling, fiber orientation, curing, heat transfer, shrinkage, and warpage. It enables optimizing charge patterns to eliminate air traps and weld lines. Calculation of required press tonnage is new, as is prediction of anisotropic cured material properties based on fiber orientation. The latter data can be used for finite-element analysis of part properties.
New displays include animation of flow and cure and the ability to scroll forward and backward in time during the simulated molding cycle. Also new is a shaded-solid view of the part, which can be easier to interpret visually than a 2D mesh when the part has complex curves. The software has a database of typical grades from major SMC suppliers. Price is $15,000. An optional injection-compression module costs $5000.
TP Composite Prepregs Come in PP or PPS
Two new thermoplastic composite prepreg products for filament winding, pultrusion, hot-press molding, or other processes are based on resins at opposite ends of the price and performance scale.
An improved grade of TowFlex continuous glass or carbon fiber impregnated with polypropylene has been introduced by Applied Fiber Systems, Ltd., Clearwater, Fla. The chemically coupled PP in new Towflex CCPP is said to offer better fiber-resin adhesion and thus improved mechanical properties. Compared with standard PP homopolymer, composite flexural strength is increased 74-80%, and short-beam shear strength is more than 50% higher, according to the company. Produced by powder impregnation and heat fusion, TowFlex CCPP comes in flexible tow, unidirectional tape, and drapable unidirectional or bidirectional fabrics, as well as consolidated laminate sheets. The fabrics can be used to enhance performance of GMT PP sheet.
Sufex-1 unidirectional carbon-fiber/PPS prepreg tape is new from TPM2, Inc., a new affiliate of Thermoplastic Pultrusions, Inc. in Bartlesville, Okla. Standard product is 12 in. wide with 55% of AS4-type fiber (33-Mpsi modulus). Price is $26-32/lb. Special orders can have other carbon or aramid fibers.
Dielectric Heaters Speed Pultrusion
If you’re looking to accelerate pultrusion line speeds, radio-frequency dielectric heating systems from PSC, Inc., Cleveland, are starting to find use in this application. The firm, which is new to the composites market, says RF heaters offer much greater energy efficiency than conventional heaters, as well as instant on/off capability.
Entry-Level Machines Cast Marble or Concrete
At the K’98 exhibition in Dusseldorf, two firms showed new “starter” machines for small- to medium-volume continuous casting of highly filled thermosets:
Model DB 10/0 from Respecta-KWM GmbH, Wulfrath, Germany, is a small, simple-to-operate machine for mixing and casting polymer concrete and mortar at 8.8 to 22 lb/min. Unlike the company’s custom-built workhorse machines, its design has been standardized and simplified to reduce cost. Options include computer control and color injection.
From ADM-Isobloc GmbH in Germany comes the Junior 3/8 F for mixing and dispensing 6.6 to 17.6 lb/min of polymer concrete, cultured marble, or onyx. Options include color addition, dual-filler metering, marbling effect, and separate degassing unit. ADM-North America is in Springfield, Va.