REKO CASTS TRACTOR ROOF prototypes in epoxy tooling with Parts-in-Minutes® polyurethane

To quickly produce 30 89-lb tractor roofs, each measuring nearly 7-feet high x more than 6-feet wide with multiple, hard-to-demould bosses, Reko International, Oldcastle, Ontario, recently turned to a series of epoxy tooling and polyurethane prototyping materials. Using a glass-reinforced epoxy paste from the RenShape® Solutions Tooling Group of Vantico A&T US Inc. for the mould, a Shore 50A Ren® silicone rubber for loose pieces and a modified Vantico Parts-In-Minutes polyurethane for prototypes, Reko generated the required functional parts for evaluation and testing.

According to Rick Stone, Model Shop and Prototype Manager at Reko Tool & Mould Inc., a part of the Reko International Group, "After we had quoted and received the job, we plotted data in our CAD/CAM software and found that the roof was so large we had to print it out at 3/4 size. That was a shock, along with the realization that there was no fast-setting material with a pot life long enough to shoot the part."

Material Selection

Stone met with his RenShape Solutions technical representative to review materials requirements for the roof prototypes. Based on their discussions, the East Lansing Technical Support Group began testing alternative hardener combinations that would increase the two-minute work life of RP 6455 R/H Parts-In-Minutes polyurethane resin. They established that blending RP 6455 hardener with Ren RP 6470 hardener would slow the pot life of the polyurethane to seven minutes, satisfying the needs of the Reko project.

As the next step, to evaluate polyurethane shrinkage, a single ribbed boss was cast in a small epoxy paste test mould. The resulting part exhibited the desired dimensional accuracy. Prototypers, therefore, proceeded with plans to build the full-sized tool.

Mould Building

Reko began by using CAD data to cut a Ren Shape® 450 model. The model was sealed and released with paste wax. The core half of the tool was then started by applying two layers of RP 4026R/RP 1510H surface coat. After the surface coat became almost tack free, a coupling layer was brushed on followed by a 1/4 inch of RP 569R/RP 569-1H laminating paste. Next, 1/4-inch thick copper water lines were installed and covered with three piles of epoxy/fiberglass to build up a 3/8-inch thick tool wall. Once the tool cured, RP134 Si R/H silicone rubber inserts were cast, vents were drilled and square block ejectors were added. The core side of the tool was waxed out for wall thickness of the part and then the cavity half was formed using the same process.

Casting Parts

Given the size of the tool, two meter/mix dispensing machines were used to shoot each roof through multiple injection holes. The first shot was experimental because a precise demould time was not established for the RP 6455 R/H/RP 6470H polyurethane system. The prototype was left in the closed tool for two hours and then removed while it was still soft. Toolmakers determined that they could fill the mould within the seven-minute work life of the polyurethane, but demould time would have to be increased and more ejectors were needed. An air ejection system was, therefore, added along with additional vents. Exotherm did not appear to be a problem so water lines were not used for the second shot.

The mould was then prepared and closed and 89 lbs of RP6455 R/H polyurethane with RP6470 hardener was dispensed through the two sprues into the mould until material flowed from the vents. The prototype was shot the first thing in the morning and allowed to remain in the mould until mid-afternoon. The part was acceptable but still difficult to demould. Still more ejectors were added in problem areas of the tool core so that the mould could be opened while the prototype remained in the cavity half of the tool. Resulting parts exhibited good accuracy with virtually no warping. Based on the initial prototypes, Reko's customer made some design changes, but the mould was altered to add more ribs, and additional prototypes were made before proceeding to production parts that were moulded using structural foam.

Reko International was founded in 1976 by Steve Reko. In 1987, Reko Tool & Mould Inc. and its fixture building division were formed to produce injection and compression moulds, lost core tooling, prototype and vacuum form tools, models, patterns and trim dies. More recently, the company entered the rapid prototype arena building fast-setting polyurethane parts produced in silicone rubber, fiberglass and epoxy moulds. Reko Tool & Mould was awarded its ISO 9001 certification in 1997, confirming the group's capabilities as a world class operation.

Vantico Inc.

WASHINGTON MILLS REAPS COST SAVINGS with environmentally safe synthetic lubricant

Selecting the right lubricant for milling applications is critical for ensuring budgetary and productivity goals. For Niagara Falls-based Washington Mills, a large worldwide producer of abrasives and electro minerals, this became evident when untimely, costly breakdown of its milling operation equipment began affecting its distribution to the refractory, electronics, automotive and other high-tech ceramics industries. This challenge prompted the company to switch from a mineral-based lubricant to a synthetic for improved protection. Washington Mills now uses the non-asphaltic ANDEROL Polyguard 4100 open gear synthetic lubricant. Today the company's operations run smoothly 24/7/365 facility without unpredictable ball mill shutdowns. Other benefits include less volatile organic carbons (VOC), decreased disposal costs and prevention of metallurgical fatigue.

"Since implementing the ANDEROL Polyguard 4100, we have reduced wear and replacement of pinion gears, for an annual cost savings of about $30,000," says Brian Fisher, maintenance superintendent of Washington Mills. "This lubricant will allow us to better reallocate money and manpower toward other business priorities."

The lubricant's excellent cling properties enable it to quickly stick on to the ball mill's gears to form a protective shear coating, providing excellent lubrication while cooling the gear teeth. These characteristics have significantly reduced site maintenance and virtually eliminated schedule repair, thereby creating a more economical and productive business for Washington Mills.

Easy Maintenance, Extended Performance

The immediate improvements Washington Mills gained from the lubricant's performance included excellent cold-weather pumpability, negligable maintenance and alleviation of excessive spare-part inventory previously required in anticipation of equipment failure.

In addition, low viscosity analysis readings of the ball mill's surface have indicated little to no friction or misalignment of gears, which has enhanced machine reliability and performance. Another major benefit of ANDEROL's synthetic lubricant is a significant reduction in Washington Mills' disposal costs and emissions of hydrocarbons into the environment. Also, due to the absence of asphaltic materials, the lubricant has a transparent amber colour, allowing gear teeth to be easily viewed and inspected without stopping the machinery.

"Using a non-asphaltic product has provided a more user-friendly environment, virtually eliminating weekly clean-ups," says Fisher. "Our previous lubricant left heavy black residue throughout the entire plant that employees would track all over the place."

The ANDEROL Polyguard 4100 also enhances productivity and machinery performance by pumping quicker. Its viscosity allows consistent flow during winter months without the need of a heat trace.

Peace of Mind

Washington Mills found that the proprietary chemistry of the ANDEROL lubricant promotes evaporation at nearly twice the rate of its previous products. This results in rapid set-up on gear teeth to prevent metal loss. The lubricant's additive system also enhances milling output by providing EP protection, showing less instance of wear, thereby optimizing equipment efficiency. All of these lubricant features work together to improve the process of milling abrasives and delivering them to customers.

"Our previous mineral-based, asphaltic lubricant required annual replacement of pinion gears which took between 16-24 hours at each change-out," says Fisher. "The ANDEROL Polyguard 4100 gives us the peace of mind that adequate lubrication is happening around the clock and equipment failure is the exception and not the rule."

Upon request, ANDEROL tailored the amount of lubricant delivered to Washington Mills into 180 kg drums, which has streamlined storage and usage. The company will also provide the mineral producer with a full range of lubricant-related services that will continue to enhance the results over the long term.

"From this point on we will be able to focus our efforts on delivering customers the highest quality abrasive grain and specialty electro-fused minerals without having to worry about whether or not our equipment will work or negatively impact our bottom line," says Fisher.

ANDEROL Inc.

PCL TOWER CRANE uses radio remote control

At the PCL pipe fabrication plant in Nisku, Alberta, a tower crane is used to load and unload trucks. To provide increased safety for this operation, PLC uses radio remote control.

PLC is one of Canada's largest construction companies. At their Industrial Fabrication Facility, raw materials are unloaded and finished pipe is loaded onto flatbed trucks. An 85 foot tower crane with a 135 foot boom was their choice for efficiency and cost effectiveness, as the crane can access a wide area without the need for a large enclosed structure to be built.

One drawback of the tower crane was the need for an operator to be located in a small cab at the top of the tower. The operator's line of sight was restricted and a signal person was required to give the operator directions. PCL brought the operator out of the cab and down to ground level by using a radio remote control system.

With the help of Wayne Zuchotzki and Wade McIntyre of Hoisting Ltd. in Edmonton, a distributor of remote control and other crane products, PCL chose a Cattron-Theimeg™ AT series remote control system. Hoisting Ltd. arranged to have a Cattron-Theimeg™ paddle-type transmitter specifically engineered to interface with the tower crane's unique controls.

Now, the PCL crane operator can handle the loading and unloading on his own, positioning himself in the best vantage point out of harm's way. Safety and efficiency have been greatly improved.

"Radio remote control makes a big difference in this application," says Wayne Zuchotzki, "PCL has been using the system for more than two years and are definitely happy with the results."

Cattron-Theimeg Canada Limited

Canadian Industrial Equipment News July 2003