Pultrusion tops the news in equipment for composites.

From entry-level systems to high-end units with all the bells and whistles, you could find it all among the new hardware exhibits at this year's SPI Composites Expo in Nashville, Tenn. Pultrusion accounted for the greatest number of developments, but there was news for filament winding, RTM, SMC, and spray-up, too.

PULTRUSION PROCESS MONITOR

On-line process analysis is now available to pultruders in a relatively inexpensive and easy-to-use instrument from Pultrusion Dynamics Inc. (which just became a division of Creative Pultrusions), Oakwood Village, Ohio. The Topscan Process Optimizer is a step beyond the company's Topdie off-line computer simulation of temperature profiles within the pultrusion die, says president Joe Sumerak. Topscan reads up to 32 die thermocouples and a line-speed encoder to give a real-time view of what is actually happening in the process. The touch-screen display. lets you overlay color-coded curves of temperature profiles for different areas of the profile at different positions along the length of the die. Or, you can superimpose current performance and a reference standard. The temperature curves can also be animated to show how they change when line speed is altered or when a process upset occurs - caused, for example, by a sudden draft of cold air.

Topscan data can be printed out or downloaded to a PC. For process development, it can be used to monitor temperatures in disposable thermocouples embedded in a profile. The instrument also contains a bath for SPI gel and exotherm tests. Price with top-mounted color ink-jet printer is $9500.

A Windows-based PC control system for pultrusion is new from Composite Machines Co., Salt Lake City. The ATP Delta controller for the company's high-end machines gathers up to 206 data points on temperature, speed, or force and displays both instantaneous data and historical trends. Two variables can be plotted simultaneously. The data can be downloaded to a PC for analysis using the company's Pultrusion Analysis Software. In addition, complete set-up recipes can be stored for instant recall.

NEWEST PULTRUSION MACHINES

The newest supplier of pultrusion hardware is Martin Pultrusion Group, Hudson, Ohio. It was founded by industry veteran Jeff Martin to act as a single source of machinery, tooling, technology, and training. The company's line of Durapul machines has touchscreen PC controls and reciprocating-clamp pullers that get a 20-in.-long grip on the part. Down-acting clamps do not displace the part from the production plane, thereby reducing warpage, Martin says. He adds that these machines have a special die-alignment system that allows not only raising and lowering the tool, but also pivoting it in two dimensions to counteract any bowing tendency in complex profiles. Four standard models have pulling forces of 3-12 tons and product envelopes from 10 x 4 in. to 40 x 12 in.

Martin Pultrusion also offers standard Duralife dies of P-20 or 4140 steel, as well as Duralife 55 dies made of A2 steel hardened to 55 Rc. The latter are more brittle but are said to last longer. In addition, Martin supplies Duralife Thermally Enhanced Dies, which have a unique heating pattern determined for each die design. Die reworking services are also available.

In the technology area, Martin Pultrusion is a new licensing representative for the Pulrite process from Caledonia Composites of the UK (PT, Jan. '96, p. 25). Pul-Rite involves folding dry 'glass cloth into an envelope that can be filled with a variety of granular core materials in order to save weight and cost.

Martin is also exclusive representative for the Braid Insertion Device from A&P Technology. It's a special S-shaped mandrel extension that allows production of hollow profiles from a continuous tube of braided reinforcements. Two wheels feed the braid over the curved mandrel extension (whose shape prevents it from being pulled into the die) and onto the straight part of the mandrel, which projects beyond the die entrance. Although the mandrel "floats" within the die, Martin says the uniform thickness of the braided sleeve keeps the mandrel centered.

FILAMENT WINDING NEWS

In the last year, EnTec, Salt Lake City, has introduced dual-sided machines that can wind on one side while mandrels are being loaded or unloaded on the other. Different products can be wound on either side, too. These machines can have multiple spindles on each side. The spindles are arranged along common axes, and the winding carriage's "rest" position is between the spindles or groups of spindles. A larger dual-side version for pipe has the carriage move along a parallel axis between two mandrels. It can wind alternately on either side.

Also new from EnTec is WiMaX 2, an upgraded version of its computer control, which is based on a Pentium PC. New features include unlimited pattern length, ability to nm larger files, and both digital and analog I/O for controlling tensioners, uv-curing lamps, etc. Control of up to eight axes is now standard, versus six before. The system records all production data and, in case of a shutdown, provides an operator message explaining why. Because WiMaX 2 uses the same control panel as before, older WiMaX systems can be upgraded easily, EnTec says.

EnTec also has a new low-cost, entry-level benchtop winder for R&D and educational uses. It has an aluminum rail frame, chain or belt drive, and PC-based servo control of up to four axes. It winds parts up to 12 in. diam. and 4-12 ft long. A larger version winds pipe up to 60 in. diam. x 40 ft long.

A very low-cost series of winders for pipe, ducts, and tanks has been introduced at 30% lower cost than standard models by Composite Machines Co., Salt Lake City. They have a chain-driven carriage and a spindle with DC drive and digital ratio control for 10-90 [degrees] winding. The spindle can have servo drive and computer control for 0-90 [degrees] winding. Four models offer a choice of one to four spindle speeds and maximum mandrel diameters of 24 to 160 in. Maximum carriage stroke for all models is 50 ft.

For higher-end winding markets, Composite Machines offers new Cad-wind 6.0 pattern-development software. Created by Material S.A. in Belgium, the software is described as a major upgrade of the previous version. It offers new generators for circumferential, polar, and geodesic helical winding (the latter two are particularly useful for pressure vessels). Programming of parts that were "impossible" with the usual calculation methods reportedly now can be done by converting externally calculated or experimentally generated windings.

ECONOMICAL, MODULAR RTM

The new modular Spartan RTM system from Glas-Craft Inc., Indianapolis, allows processors to start with a basic system ($6600) and later expand its capabilities by adding various control modules for $400 to $1000 each. The Accu-Shot module counts pump strokes and automatically stops the machine when the preset count is reached. Accu-Flush includes a timer to alert the operator to flush the as well as a timer that indicates when parts can be demolded. Accu-Master is an automatic air/solvent flush sequencer for high-volume operations where the gun is built into the press. And Accu-Vac provides a venturi-type vacuum assist for filling molds.

Low-pressure presses for RTM, prepregging, and other uses are new from Composite Machines Co., Salt Lake City. PIE-controlled ECP presses have all-electric ball-screw drive, which is said to be much quieter and cleaner than hydraulics. The lower platen and mold half are mounted on a cart that can roll in and out of either side of the press. This way, one mold can be in the press while another is being loaded or unloaded outside the press. Both platens are heated. A 50-ton model has 4 x 6 ft platens, and a 75-tonner has 4 x 12 ft platens. Prices start around $65,000. The company also offers a computer-controlled resin mixing/metering/dispensing system for use with the press.

SMC PRESSES & AUXILIARIES

Relatively low-cost hydraulic presses for molding low-pressure SMC (LPMC) are available from BGF Composites Inc., Naperville, Ill., a new firm offering single-source consulting on LPMC molding. The presses are built by Jesse Engineering Co., Tacoma, Wash., which also has marketed LPMC presses through its Wallace Coast Machinery Div. in Glenview, Ill. The newest generation has five cylinders, one in the center and four on the corners. The center cylinder alone raises and lowers the platen, while all five cylinders engage for pressing. A 700-ton BGF-Jesse press with 84 x 108 in. platens, 84-in. stroke, and 250-in./min closing speed costs around $200,000. A 200-ton model runs $125,000-150,000. BGF is setting up a demonstration LPMC molding facility.

Coming later this year is a different press version that locks the upper platen against racks on the sides of the frame, while an up-acting, short-stroke cylinder on the bottom platen applies molding pressure. This new design will take advantage of new LPMC materials technology that will allow molding with as little as 35-50 psi, according to BGF technical director John Neate.

Easier mold flow and faster cures are said to result with a new radio-frequency preheater from Nemeth Engineering Associates, Inc., Crestwood, Ky. This 15-kw, 80-MHz model can heat a 24 x 24 in. stack of SMC charges up to 5 in. high. It heats 8-10 lb/min of material to 220 F. Dual timers (heat and hold) ensure that the preheater's air-powered hood opens when the press is ready for loading. Options include an exhaust blower and PIE to send production data to a host computer.

A 3-D laser dimensional inspection system used on automotive assembly lines is now being marketed by Diffracto Ltd., Detroit, for inspection of large SMC parts after molding. The company's SmartLine laser sensors can capture surface contours and features like the center of a hole, while the touchscreen computer software calculates precise x-y-z dimensions. Measurements are virtually instantaneous and can be cross-checked with much slower coordinate measuring machines. The company says readings can be made down to 0.1 mil with three-sigma accuracy while the sensor is anywhere from 4 to 80 in. from the part. The system can signal a technician's or, supervisor's beeper if off-spec parts are detected.

FOR CLEANER OPEN MOLDING

Acknowledging the recent revival of interest in electrostatic gelcoaters as a means of reducing overspray and styrene emissions, Venus-Gusmer, Kent, Wash., is offering its standard spray system with the addition of a Graco electrostatic gun.

Venus-Gusmer also has updated the "flow coater," a different approach to reducing styrene emissions in open molding. The flow coater emits a dense stream of resin rather than an atomized spray. To optimize the use of chopped glass with such a device, Venus-Gusmer has come out with the Flow Chop system. It includes a glass chopper with a special discharge chute designed to break up the glass bundles, eliminate glass dumping, and distribute the glass over the fan pattern with minimal glass "fall-off." Very little glass is wasted with this enhancement, says a company spokesman. The internal-mix device is completely airless, causes no misting, and reportedly requires only 5 g of solvent to flush.

New for boat makers is the APD adhesive putty dispensing system from Glas-Craft Inc., Indianapolis. Reliable and accurate catalyst delivery in putties with viscosities above 1 million cp is said to be ensured by hydraulically (rather than mechanically) slaving the catalyst pump to the putty pump. Also, catalyst is injected into the putty from three directions before the material enters the static mixer. This eliminates catalyst lead/lag and incomplete, "candy cane" mixes, the company claims.

While normal operating pressure is 200-300 psi, pressure on the putty is released the moment dispensing stops so as to avoid static pressure on the material, which could collapse hollow microsphere fillers. Price of the system is $12,750.

A spray-up system for making granite-appearance gelcoats is new from Composite Machines Co., Salt Lake City. Built by Resipol in Italy, the Polygran system uses an external-mix, air-assisted gun and a pumping system that can spray up to four colors simultaneously. Droplets of each gelcoat color are dispersed in the spray fan, producing the speckled granite effect. A system with training costs around $30,000.