In Process 18537

Giant all-electric multimaterial machine goes to eager novice

A new all-electric, two-shot, Cincinnati Milacron Powerline 935 helped Maca Plastics (Winchester, OH) secure a multimaterial part order from an automotive OEM. Featuring 72- and 5.8-oz shot sizes, Milacron officials think the big machine may be the largest all-electric multimaterial press in North America. Maca is fond of Milacron all-electrics, with six of its 14 machines being Milacron Roboshot units. Maca had no previous multimaterial experience and leaned on Milacron to get the press and the program up and running, including cell integration and sequencing software. The part that Maca won was actually two components previously, molded on two machines, and assembled afterward. Now the two materials are shot into one cavity, eliminating a machine, a mold, as well as extra labor and auxiliaries.

The tool itself is two cavities with three sliding cores per cavity that must move in sequence to avoid collisions. To achieve this Milacron developed custom sequencing software. The Class-A finish part is made from 12 oz of polypropylene and less than an ounce of thermoplastic elastomer. Production volumes on the component hit 30,000/month and three color changes/day. For more information on Cincinnati Milacron go to www.milacron.com.

Moldmaker unscrews caps at speed of lightning

Speed in caps and closures molding is essential, with little time available to wait on unscrewing systems. An Illinois moldmaker has reduced that time to less than a second through a patent-pending system that created a thermoplastics tamper-evident cap in an overall cycle of 12 seconds.

The PERC (programmable electric rotating core) system from moldmaker B A Die Mold Inc. (Aurora, IL) features fast, accurate positioning and has unlimited turns and programmable speed profiles. B A Die Mold reports the system has created significant reduction in the cycle needed to mold tamper-evident caps that have three ejection stages.

The system can produce almost any size-threaded part; is set up easily; and integrates well with all-electric molding machines. For more information visit www.badiemold.com.

Building an extrusion business around composite lumber

In response to the booming composite lumber market, Elk Composite Building Products (Lenexa, KS) has expanded with Davis-Standard extrusion equipment, adding five profile extruders and three sheet lines to its 195,000-sq-ft plant. The company will use the machines to make decking, fencing, and railing products; a market Elk executives feel will see double-digit growth in the coming years.

The 140-mm extruders and sheet lines, extruders through stackers, will make decking and panels that combine oak flour and polypropylene for a durable composite lumber with the texture and look of real wood. Five colors and three surface styles will be available. The decking is said to resist sagging, warping, and splintering. For more information on the extrusion systems, go to www.davis-standard.com.

Shelf-mounted robot looks down on molding

Space saving and flexibility were tops on Decoma?s wish list when it set out to design a production cell to make bumpers and sill covers for the Chrysler PT Cruiser and Audi A4 convertibles at its Sulzbach, Germany facility. Instead of a linear layout, where postmolding operations and robots would fall in line after the injection molding machine, occupying a great deal of floor space, the company opted for shelf-mounted six-axis articulating-arm robots from Kuka that actually sit on top of the press.

The robots remove the parts from the cavity, and in the case of the sill cover, cut away the runners as well. Decoma bought two Kuka KR 150 KS that use a PC-based controller and are affixed to the top of the press, saving floor space.

After molding, one robot removes the 4-kg fascia and places it onto a special fixture. There, the robot removes runners using a blade attached to its gripper, dropping the scrap into a bin. Finally, bumpers are placed onto a conveyor and carried out to shipping.

During sill-cover production, the robot pulls two covers out of the machine and places them on a table. Next while the robot holds the parts in position, 14 blades from the table cut off scrap from the 14 gates at once. From there, the sills are moved to a conveyor and the robot drops the scrap into a bin. The robots? grippers feature a vacuum system to hold the parts, and this grip is monitored by the controls.

Being lightweight and powerful allows the Kuka shelf mount to sit on top of a press without affecting the machine and be able to hold large parts.For more information, visit Kuka Robotics at www.kuka.com.

Insert molding task fulfilled with six-axis robot

When an Indiana molder decided to move from a Cartesian-style robot to a six-axis articulating-arm model, accuracy, speed, and competitive pricing were important considerations. The custom molder, which wishes to remain unidentified in print, produces about 155 million parts a year for the automotive, aerospace, appliance, electrical, and medical markets, using 63 Engel injection molding machines that range from 40- to 600-tons clamping force.

The problem application in this case was an electrical-connector component molded on a vertical Engel 85 press. This insert molding job went beyond a standard pick-and-place movement, which could have been handled by a three-axis robot, prompting the evaluation of three suppliers of articulating-arm robots.

Eight terminal pins needed to be loaded from into the mold, with four inserts going into each cavity in a two-cavity tool. Four feeder bowls supplied the inserted pins, which had very little wiggle room. Placement tolerance for the inserts was +/- .0008-inch. Working within the constraints of a 36-second molding cycle, the robot was required to remove the molded components? sprues and placing each finished part in a specific bin by the operator. After this, it had to prepare for the next cycle by picking up eight more pins.

Given the process parameters, and the opportunity to propose specific equipment, Stäubli recommended two of its RXplastics90L robots paired with a CS8 control. The molder?s engineers installed the system and reported being able to program the PC-based robots with relative ease. This was aided by Stäubli?s use of SPI hardware for direct connection to the injection molding machine.

Stäubli reports that the initial installation occurred in the Spring of 2004, and the robots have performed well enough to prompt the molder to order more six-axis Stäubli systems.

For more information on Stäubli, visit www.staubli.com.

Stretching your shipping performance

Molding quality components is really only half the story for most shops. Once parts are manufactured, processors still must package and ship them in a timely fashion to their customers, and this portion of molder?s business is often overlooked. Rev-A-Shelf (Louisville, KY), a custom injection molder whose primary market is appliances, decided to pay shipping a little attention, installing Lantech Q-300XT stretch wrappers. The Lantech system works by automatically cutting the film on a finished load and restarting the film on the next one.

This eliminates the need for a worker to manually perform these functions, freeing them for more value-added work, and it also reduces fork-truck downtime. Rev-A-Shelf actually reduced their fork-truck fleet by one after the Lantech installation, but company officials report that it feels as though the number of trucks has doubled.

Previously, the company had one person who banded together cartons on the pallets or skids, doing 10 to 20 while trucks waited, and then sending them to the stretch wrapper, where they started the film on the pallet and cutting it once the pallet was wrapped. The company was able to push through 300 pallets/day with this system over two shifts, but it took a great deal of resources.

The Q-300XT eliminated this bottleneck thanks to its flexible, robust design. The system features a mast-height extension, which allows it to handle loads up to 110 inches high. The turntable can support loads up to 4000 lb and runs from 1 to 12 rpm. The Power Roller Stretch on the Lantech prestretches film 200% so less is used.

For more information on Lantech visit www.lantech.com.