Machining Value into
Pressure Molded Products

Louisiana-based Industrial Plastics and Machine has found success
by specializing in the manufacturing and machining of Teflon rods,
tubes and sheets and then selling these items exclusively through its distributor network.

Sidebar: Processing an Idea

BY KAREN M. KOENIG

Things are heating up at Louisiana-based Industrial Plastics and Machine -- and it's not from any cajun hot sauce.

The 120,000-square-foot Baton Rouge company which specializes in manufacturing molded Teflon rods, tubes and sheets is also creating a niche for itself by machining envelope gaskets, solid ring gaskets, spacers and other specialty items.

"We've always done machine work," said Julius Beard, vice president of the 18-year-old company. "Machining accounts for approximately 10 percent of our business."

Stock parts and specialty items are sold exclusively through IPM distributors. "Our customers are strictly plastics distributors, even for parts," Beard said. "In this day it may be considered unusual to sell strictly to distributors, but we find we do more business that way." He added that IPM avoids the conflict of "competing against our own customers" by not selling direct to equipment manufacturers. IPM's distributors are located throughout the United States, Canada and Mexico.

Machining Adds Value to Products
Although it currently accounts for a small portion of IPM's business, the machining area is becoming a growing profit center for the company. It is here that IPM uses many of its custom capabilities to manufacture gaskets, spacers, disks for pneumatic pumps and other types of products. "The customer will send in drawings and specifications of maybe just one or two of the pieces for us to make. So a lot of times, we don't know what the (completed) product is," Beard added.

"We specialize in small runs -- anything from one to 500," said Roy Hunt, sales and marketing manager. "It's done as a value-added service for our distributors."

Much of the machining is done on the company's eight automatic Victor lathes and two Bridgeport milling machines. A Marvel bandsaw and a Hendrick panel saw are also used for cutting stock to size.

"We're looking at getting some CNC equipment, though it will be strictly lathes or milling machines," Beard said, adding that there are no plans to purchase routers or other types of trimming machines. "A lot of our distributors have their own routers for that type of work," he said.

Only carbide-tipped tooling and high-speed steel tooling is used for milling and cutting the material. "With any filled compound, such as carbon or glass, you have to use carbide-tipped tools. For the virgin material, we can use high-speed steel because it's not as abrasive," Beard added.

Although Teflon is the primary material used at IPM, the company will manufacture and machine others types of material. "One nice part about being a custom shop is that it gives us a great deal of flexibility," Beard said. This flexibility extends not only to IPM's capability for molding and machining but also to the shipping of product to customers.

Called the Fastship Program, IPM can ship, within one working day, small orders of compression-molded Teflon rod or tube from stock. Normal shipment of small quantities of Teflon products can be made within three working days, with large orders shipping within seven working days.

Compression Molding Rods & Tubes
Although inventory is maintained on some of the standard rods, tubes and sheets, IPM will also manufacture products to customers' exact specifications. "We have hundreds of molds that range in size from 1 inch diameter to as high as 32 inches," said Paul James, engineer.

"Each molder has a sheet that tells him what size mold to utilize and what size poundage (of resin) to put in. The tubular molds, for the most part, vary in the outer dimension by 1/4-inch increments in molds up to 12 inches in diameter. We also have molds that can go to a 32-inch outside diameter. The inside diameter for the tubular molds varies by 1/8-inch increments," James said.

Molds for rods will vary by 1/4-inch increments in the 1-inch to 9-inch diameter rods, then by 1/2-inch increments for the 91/2-inch diameter rods up to the 15-inch diameter rods. Larger molds vary by 1-inch increments, up to 32-inch diameters.

The molding process is done manually by experienced molders who determine the compression points and set times for each job, James said.

According to James, "The amount of time it takes to mold a rod or tube depends on the the amount of mass. You slowly compress the material, and when it reaches the compression point, it gets held under that pressure, setting the particles to coalesce," he said. "It gets compressed from both directions, giving it sufficient strength, and is then sintered in an oven at 700F. That's when it begins to coalesce," James added. "Once it coalesces, the cooling process begins, and the temperature in the oven drops approximately 75 degrees an hour," he added.

Hunt offered an example. "It would take approximately one hour to compression mold a 6-inch rod, including 30 minutes molding time, at 1,800 pounds of pressure. Larger rods could take up to 4,600 pounds of pressure," Hunt added.

To sinter rods, tubes and small sheets, IPM has nine Grieve ovens which it runs approximately 24-hours a day. The temperature control on these ovens is CAM driven. The company also has two larger, auto programmable New England Oven and Furnace ovens for the manufacture of large sheet stock.

Manufacturing Sheets & Billets
In manufacturing sheet stock, resin is measured by weight then poured into the mold cavity and leveled. Standard press plates are 36 inches by 36 inches and 48 inches by 48 inches, with thicknesses ranging from 3/8 inch up to 4 inches. "The whole operation, however can be customized. For example, we usually vary by 1/4 inch thick, but we can also vary by 1/8 inch," James said.

According to Joey LeBlanc, press operator, the RD Wood & Co. press molds from the bottom, applying pressure of approximately 3,800 pounds per square inch to the nickel-plated mold. "It takes approximately 25 minutes to compress, then it sits and holds the pressure for another 25 minutes," LeBlanc said. The plates are then stacked and heated at approximately 720 degrees in the New England ovens, and sintered at approximately 500 degrees for approximately two hours, he added. For quality control and tracking purposes, "Each plate has its own number mike on the corners. We can also track the lot number," LeBlanc said.

Large billets of stock are skived using a Wyson cutter. The billets -- sometimes weighing 800 pounds -- can be skived in thicknesses ranging from 10 mil to 1/4 inch, James said. The skived sheets are cut to size on a Hendrick panel saw, then heated to approximately 500 degrees and flattened in a 50-inch by 50-inch press where they are held under pressure until cool. Skived Teflon sheets are available in 24-inch squares, 36-inch squares, 48-inch squares and 60-inch squares; rolls are also available. Standard thicknesses for the skived sheet range from 1/64 inch to 1/4 inch. "One nice thing about being a custom shop though, if someone wants 3/8-inch, we can make it," James added.

Processing an Idea

Industrial Plastics and Machine began in 1979 as a joint venture between Julius Beard, vice president, and Jim Benham, company president.

"I was in the valve repair business and used a lot of Teflon products. I had a manufacturer come in one day who said he could mold the products for me direct. I thought that was a good idea (for a business).

"I bought from him for a couple of years before I got together with Jim, who had just sold his machine shop. We went out on our own...and that's how it started," Beard said.

Today, the Baton Rouge, LA-based company processes approximately 15,000 pounds of resin per week which it purchases from companies such as DuPont and ICI. Its standard product lines of compression molded rods, tubes and sheet are available in 55 materials including: virgin Teflon, glass-filled Teflon, carbon-filled Teflon, carbon graphite-filled Teflon, calcium fluoride-filled Teflon, graphite-filled Teflon, bronze-filled Teflon, moly/bronze-filled Teflon, moly/glass-filled Teflon, poly/comp 185-filled Teflon, moly-filled Teflon, ekonol-filled Teflon, ceramic-filled Teflon, graphite glass-filled Teflon, green glass-filled Teflon, blue glass-filled Teflon and Fibralon (a hybrid of Teflon and Kevlar)

"The virgin material and glass-filled are the most popular," said Roy Hunt, IPM sales and marketing. The company can custom-tint Teflon to customer specifications, he added.

IPM can also custom machine parts for customers, including gaskets, spacers and disks. According to Beard, approximately 10 percent of IPM's business is from machine work.

Plastics Machining & Fabricating
P: (847) 634-4347 F: (847) 634-4379 EMAIL: hfrankurba@aol.com	P.O. BOX 1400 LINCOLNSHIRE ILLINOIS 60069