Cutting Tools For Plastic
Since there is such variety in plastic material, tooling has to be designed to perform under a wide variance of conditions. Consequently, selecting the right tool for the job may seem complex, but a few general guidelines can be followed to simplify the process.

Plastic material can be classified into two general categories; soft and hard for machining purposes. Soft plastic material requires single or double edge "O" flute tools, which are manufactured in straight or spiral configurations. (Figure 1 and Figure 2) Hard plastic requires double edge "V" flute tools, (Figure 3) spiral "O" flutes with hard plastic geometry. Three edge finishers are recommended (Figure 4). The tool materials for most of these router bits are readily available in high-speed steel for hand operations and solid carbide for CNC machining. One resource is Onsrud Cutter's website at www.plasticrouting.com. It provides specific tool recommendations by tool material with feed and speed data included.

To trim plastic, the arbor mounted saw blade (Figure 5) was developed to remove flashing from formed parts with use of a 3-axis router. These multi-tooth, carbide tipped saw blades allow the user to trim parts on the horizontal from a vertical tool position. The geometry of the saw blade is specific in terms of soft and hard plastic and slow and fast feed rate. The five-axis CNC router user has also embraced these tools because of left and right hand rotation cutting capability. Besides trimming, the saw blades are well suited for grooving in the body of the part.

Drilling

Drilling has long been a problem in plastic with the problems of chip wrap in soft plastic and crazing in hard plastic material. Drill bits (Figure 6) with a 60-degree point and a flat face rake provide the best plunging point to date in a wide variety of plastics. The drill reduces the stresses introduced into the hole walls and will provide a clean hole surface without clouding or crazing typical in standard drills.

Thickness

The thinner the plastic the more easily it will chip. Therefore the blade will require more teeth, the rake angle should be lower, and, particularly with extremely soft or paper thin plastics, the probable need for sharp top bevel angles.

The harder the plastic the more apt it is to chip when being cut. When experiencing chipping, increase the number of teeth per blade. However, should the material show signs of glazing or overheating, reduce the number of teeth. As stated previously, soft plastics require fewer teeth.

Heat sensitive plastics require fewer teeth, more radial clearance angle and more tooth overhang.

Many blade manufacturers specialize in the design and manufacture of blades specifically for the cutting of plastics. Most of these manufacturers have learned the importance of the careful selection of fabricating materials, the differences in blade design required for successfully cutting various plastics and have acquired the latest machines and techniques needed to produce and test their products.

Proper saw blade sharpening is also critical to long blade life and "like new" cutting performance. Contact the saw blade manufacturer or a factory authorized sharpening facility to ensure that your saw blades perform as they did when they were new.

The following manufacturers and suppliers offer a wide variety of tooling specifically designed for cutting, drilling, trimming and machining plastics. For additional information, a contact, phone number and E-mail address follows each manufacturer's listing. Complete contact information can be found by clicking here. In the January/February 2003 issue we will debut a new series on Routing and Trimming of plastics.

The series will be written by Van Niser of Onsrud Cutter. Onsrud Cutter manufactured the first router bit in 1920 and will ship its 22,000,000^th tool in 2002. They serve the wood, non-ferrous, and plastic market with tooling for all types of routers, but specializes in tooling for the CNC where close tolerance, high production, and long life are critical. Onsrud Cutter developed the first tool for plastic in 1986, and today, offers several hundred router tools directed at the plastic fabricator and former.

A.W.E.D. has new end mills in a variety of sizes for cut and finish operation that will leave a polished edge available for immediate shipment, (mm sizes). The process requires precutting the shape, then following with the finishing end mill for the final touch. Deep holes can be reamed to give a polished finish. The process requires the holes to be pre-bored to a few thousands smaller, then the reamer will give the exact size desired. End mills are available in sizes up to 1/2" and reamers up to 3/4". Contact Victor Miranda, A.W.E.D. at 770-831-9800, E-mail: awed-machine@aol.com.

Recognizing the need in the marketplace, BC Saw & Tool Inc. has designed a carbide-tipped saw blade that provides a superior finish cut in sheet and extruded plastics. Manufactured in Japan to meet the increasing need for clean cuts, this blade utilizes unique blade geometry and materials to ensure consistent finish quality, reducing secondary edge finishing and losses due to damaged or waste material. Blades range in size from 10" to 16" diameter and can be run on table and beam saw machines. Contact Brett Reid, BC Saw & Tool Inc. at 416-251-2236, Email: breid@bcsaw.com.

Craftics, Inc. sells a variety of drill bits for plastic and particularly acrylic, including the Plas-Drill series, Pro series and Plexi-point series. These bits drill clean without chipping, cracking or gumming up. Craftics also sells saber saw blades designed to give a smooth cut in acrylic, polycarbonate and styrene. Each package contains one blade for material up to 1/8" thick (gold) and one for material thicker than 1/8" (green). Designed to cut acrylic, polycarbonate and styrene so smooth that the edges can be polished. Craftics also distributes Onsrud router bits and carries a line of FS Tool circular saw blades for plastics. Designed for acrylic, polycarbonate and styrene, the blade will cut single or multiple stacked sheets. Eight and ten inch blades have a 5/8" arbor, 12" and 14" blades have a 1" arbor. Sharpening available. Contact Dave Granthem, Craftics, Inc. at 505-338-0005, E-mail: craftics@craftics.com.

Forrest developed their No-Melt blades to eliminate chipping and the formation of melted burrs, residue buildup on cross-cut sections of plastic materials. They also offer the Duraline Thin-Rim saw blade for cutting fine, fragile and thin-walled materials such as 1/32" to ¼" acrylic sheets, engraving stock and plastic extrusions. The No-Melt and Duraline Thin Rim are part of a family of Forrest blades that are specifically engineered and hand straightened to deliver peak performance. Forrest also has excelled in designing custom blades for cutting nylon and polypropylene and for overcoming other cutting challenges and problems. Contact Charles Bazikian, Forrest Manufacturing at 800-733-7111.

FS Tool Corporation manufactures the LNM series of "non-melt" saw blades specifically designed for plastics. These "non-melt" blades have a thin kerf, negative hool and modified triple-chip tooth design which help eliminate melting or chipping when cutting single or multi-stacked plastic sheets. They are well suited for cutting acrylics, delrins, PVC, styrenes and ABS (Cycolac). Contact Patricia O'Flaherty, FS Tool Corporation at 905-475-1999.

FTM, Inc. carries a full range of cutting and trimming tooling specifically made for the plastics fabrication industry. Our saw blades, router bits and "plexi point" drill bits will give you better results than products designed for wood or metal. Don’t be fooled by advertisements for "general purpose" tooling that claims to work on wood, metal and plastics. We supply cutting tools that are designed to eliminate chipping, cracking or melting when working with plastic. Using the correct tooling will get you the professional results you expect. Contact David Greer, FTM, Inc. at 530-626-1986 E-mail: info@123ftm.com.

LEUCO announced availability of their new Topline Plastic carbide-tipped saw blades designed specifically to cut plastic materials. LEUCO manufactures a complete line of saw blades exclusively for plastic. Manufactured in France under strict ISO 2002 quality control, this product sets a new high quality level for plastic tooling. Initially, LEUCO will market Topline Plastic blades exclusively in the US. Contact Ken DeMarce, LEUCO Tool Corporation at 770-459-5784, E-mail:kend@leucotool.com.

Onsrud Cutter’s 2002-2003 Production Routing Catalog (OC-02) offers over 1,800 products for the CNC/production routing industry. The expanded catalog includes new and proven products for the wood, plastic and non-ferrous markets. The addition of 250 new products makes the catalog one of the most comprehensive sources for solid carbide, high-speed steel- and carbide-tipped routing tools available today.

Onsrud's redesigned websites, www.onsrud.com and www.plasticrouting.com, feature customer friendly navigation for improved speed and ease of use. Visitors can download catalogs, use a product search engine for proper tool selection and find a feed rate table on the site. Distributor names and locations are listed to facilitate the location of suppliers. Many technical questions can be answered using their new FAQ and industry link pages. Contact Joanne Smith, Onsrud Cutter at 847-362-1560, E-mail: jsmith@ansrud.com.

Safranek Enterprises’ Her-Saf Screw-on Tooling is now being used in both automated and manual machines as well as handheld tooling. These bits are also known as Quick Change Cutters because they reduce downtime when changing bits: the arbor stays in the collet while the dull cutter is screwed off and a new cutter is spun on in its place.

The advanced cooling design extends the life of the carbide and, depending on the material being cut, improves the cut considerably. The structural design ensures a balanced tool capable of 22,000 rpms. Contact Linda Wyant, Safranek Enterprises Incorporated, at 805-466-1563, E-mail: sales@hersaf.com.

Southeast Tool, Inc. now offers a solid carbide two flute radius O flute for plastic cutting. The benefit of the two-flute tool is a better edge finish. This is especially true on problem materials. In addition, the O Flute design helps in the chip curl to keep the chips from rewelding to the part that is cut. The tool is currently available in 3 sizes with more planned soon.

Southeast also offers a solid carbide two flute straight O flute with the same benefits as the radius. It is currently available in 5 sizes with more to come. Contact Chuck Hicks, Southeast Tool at 828-465-7012, E-mail: router@southeasttool.com.

Techno, Inc. offers a full line of cutting tools for the plastics, woodworking and metal cutting markets. They also offer special set packages to accommodate specific markets. Selecting cutters to produce optimal finishes relies heavily on machine federates, spindle rpm, material grades and cutter type. Techno keeps an extensive inventory of tooling. In addition to cutting tools, Techno also offers a full line of tool holders, collets and other tooling accessories. Contact Herb Arum, Techno, Inc. at 516-328-3970 ext. 370, E-mail: hrarum@techno-isel.com, ask for Techno H841 Routing Tools Catalog.

Vortex Tool Co., Inc. manufactures and has in stock over one hundred individual router bit designs specifically for machining plastics. Because they are the manufacturer and deal direct to the end user, Vortex offers customers quality tooling and timely responses at the best possible price. One of the most recent tool geometries created by Vortex is its "low helix" series. "Low helix" bits are available in one, two, or three flute designs. They provide fabricators smooth, clean cuts right off the router. Contact Mike Serwa, Vortex Tool Co., Inc. at 715-355-7707, E-mail: mikes@vortextool.com.