The fast pace of today's product introduction cycles requires that suppliers meet shortened lead times for delivering product. Customers need the confidence that a supplier will deliver as promised. A missed delivery date can have a disastrous effect on a new product's marketing plan.

Rimnetics specializes in reaction injection molding (RIM), a process in which two or more liquid chemical components from separate tanks are fed through high pressure supply lines to a chamber where they are mixed by high-velocity impingement, and then injected into the mold at low pressure. The process is similar in concept to the familiar 2-part epoxy mix. With RIM the reactants become a low viscosity, exothermic, expanding material which readily flows into the mold. In fact, the mold clamping machine has microprocessor motion control to turn the mold, helping material flow into all cavities. When a successful series of movements are perfected they are stored as a program to ensure uniform molding for the entire parts run. As the mold fills the reactants are still releasing heat while tiny bubbles swell the plastic into the finest details of the mold. Clamping forces at this stage can reach 100 tons. The finished polymer has now taken on the shape of the mold cavity. Cooling coils built into the mold transfer heat to maintain an ideal working temperature. The reactants quickly harden and parts can be removed in a few minutes. The process is tuned by the molding technicians until the program steps are certified for a full production run.

Rimnetics was founded by Minimatics, Inc. CEO Walter Chew. Minimatics is a Silicon Valley high-tech machining facility started in 1960 which has long been a prototype and production parts house for generations of technologies in medical parts, disk drives, microwave assemblies, and Swiss part. Over the years Minimatics customers such as Beckman Instruments, Molecular Dynamics, LaserScope, and others needed enclosures for their medical and scientific products. Walter Chew knew that sheet metal covers were not appropriate for these high value products. The result was to incorporate in 1985 the first RIM production shop in Mountain View, California which he named Rimnetics. Clients quickly helped the new company to fulfill a vital niche in contract manufacturing.

At first Rimnetics contracted out its tooling needs while concentrating upon the molding process itself. Employees became expert at manufacturing, finishing, painting and assembling a high quality product. Molds made by outside vendors, however, were often not satisfactory. Problems included poor quality, inappropriate mold designs for the RIM process, and long, often unreliable tool delivery schedules. Rimnetics decided to investigate making their own tooling. They started out experimenting with production equipment that parent company Minimatics had in abundance. They quickly discovered that they were on to something worth while; they had the expert knowledge to build better molds than their vendors.

The decision was made to set up a separate facility in nearby Concord, California equipped especially for tool making. This has proven to be a sound business decision for Rimnetics. Manufacturing Manager Siegfried Waaga has enthusiastically created a world class RIM shop boasting the latest in high-tech computing, CNC machining centers and the newest RIM mixing machine. Gary knew the future of his molding facility lay in the rapidly advancing software system capable of running the latest generation of CNC machines. His first CAD/CAM system was a 2D wire frame program that was limited to 2D CAM programming only. 

After analyzing the quality gains and the cost savings to be had from machining aluminum molds directly, Rimnetics began searching for a 3D CAD/CAM system that was powerful as well as practical to use.

Walter Romanenko, of Tangent Concepts in San Jose, California, introduced Rimnetics to SURFCAM, a PC-based computer-aided design and manufacturing software for Microsoft Windows 95 and NT. Rimnetics determined that SURFCAM met their requirements. “We tried demo packages of other systems and machined sample parts. Nothing worked as well as SURFCAM did, including the short learning curve. Walter, of Tangent Concepts, proved to be very helpful by handling our start-up questions.”

Waaga designed and implemented a full CAD/CAM and CNC network system throughout Rimnetics' machine shop. He now uses a network of thirteen PCs, including four Pentium machines and a Dual Pentium Pro to run SURFCAM, SolidWorks and other software. CNC machines, including four new Cincinnati Milacron mills, run code directly from the computer network, allowing the shop to run twenty-four hours a day, seven days a week. SURFCAM's ability to produce large amounts of error free code permits the shop to run large program files without problems. With SURFCAM's solid model verification software, it is no longer necessary to proof programs at the machine. In one instance, a program for roughing out a molding tool ran unattended for over 300 hours!

Another important link in the Rimnetics' communication network is their website. While the site serves as an on-line company brochure, it's other value is for File Transfer Protocol (FTP) - an Internet standard which handles any size of data transfer by opening a continuous high speed link limited only by the sender's connection (T1, Frame relay, ISDN, or modem).

Simple instructions on the website explain how to transfer a file to the site without the need for a password. Both of Rimnetics' Bay Area locations have T1 or DSL conections which reliably download at high speed. This encourages clients to send CAD files to evaluate and bid in as little as 24 hour.

The Rimnetics system “goes into gear” when a potential customer forwards an IGES or any other design file for review. Tooling and finished molded part are quoted and any missing design information noted. Many Rimnetics' customers submit SolidWorks design files that are often helpful in calculating part volume to estimate the amount of material needed to mold the part. Gary encourages SolidWorks files since they can be saved directly to the SURFCAM file format for manufacturing.

When a tooling order is received, all required mold features such as water passages, ejector pin locations, base mounts, gating and venting are added using SURFCAM. Machine code is then easily generated. With SURFCAM, manufacturing can now go through the design and “code ready” process in just a few days. As a result, tool machining can now be accomplished in weeks instead of months. The finished code is sent to the computer server for distribution to the shop floor.

Rimnetics' machining centers run on Microsoft Windows NT using the latest graphical interface and are networked for continuous loading. Both rough and finish cut instructions are included in the same program. As file sizes get larger, reliability and speed become increasingly important. It is not uncommon for a total of 200 MB of code to be transferred to complete a tooling order. Reliable, continuous distribution of machine code is key to a twenty-four hour operation.

With all this technology in place, Rimnetics can quickly turn around jobs. On one rush order, a file was received electronically on Thursday and code sent to the shop floor by Friday. Two machining centers completed the machining over the weekend and by the following Wednesday, the molds were completed and the tooling was delivered to the molding shop. Molded first article parts were shipped to the customer by Thursday, just eight days after Rimnetics first received the design file. That is an impressive demonstration of what can be done with today's computer technology.

Rimnetics has now achieved high-end aluminum tooling at lower costs and can quote substantially shorter lead times.

© 2008 Rimnetics, Inc.   Mountain View & Loomis, California | Rimnetics is ISO 9001:2000 Certified