Machinists Handbook
- 1. Quadrant’s Machinist Handbook You inspire … we materialize®
- 2. The World’s Leading Manufacturer of Plastic Stock Shapes Plastics increasingly replace traditional materials such as bronze, stainless steel, cast iron and ceramics. They are chosen for improved performance and TABLE OF CONTENTS cost reduction. Plastics can: Coolants. . . . . . . . . . . . . . . . . . . . . . 5 • Reduce Weight • Eliminate Corrosion Annealing . . . . . . . . . . . . . . . . . . . . . 6 • Improve Wear Performance in Unlubricated Conditions Machinability. . . . . . . . . . . . . . . . . . . 9 • Reduce Noise Drilling . . . . . . . . . . . . . . . . . . . . . . . 10 • Increase Part Life • Insulate, both Thermally and Electrically Sawing . . . . . . . . . . . . . . . . . . . . . . . 16 Typical applications for engineering plastics range from semiconductor Milling . . . . . . . . . . . . . . . . . . . . . . . . 19 processing equipment components to heavy equipment wear parts, to food Turning . . . . . . . . . . . . . . . . . . . . . . . 21 processing industry components. Machinable plastic stock shapes (sheet, rod, and tube) are now available in more than 50 grades, spanning the performance/price range of both ferrous and non-ferrous metals to specialty ceramics. Plastics capable of long term service up to 300°C, with short term exposures to 500°C are now available. As the number of material options has increased, so has the difficulty of selecting the right material for a specific application. 2 You inspire … we materialize®
- 3. The following guidelines are presented for those thumb for machining tolerances on plastics is 0.1 to 0.2% of the nominal size machinists not familiar with the machining although tighter tolerances are possible with very stable, reinforced materials. characteristics of plastics. They are intended as guidelines only, and may not represent the most Quadrant Engineering Plastic Products’ stock shapes can be easily machined on optimum conditions for all parts. The trouble- ordinary metalworking and in some cases on woodworking machines. However, shooting quick reference guides in this booklet there are some points which are worth noting to obtain improved results. should be used to correct undesirable surface In view of the poor thermal conductivity, relatively low softening and melting finishes or material responses during machining temperatures of thermoplastics, generated heat must be kept to a minimum operations. All Quadrant materials are stress and heat build up in the plastics part avoided. This is in order to prevent relieved to ensure the highest degree of machi- deformations, stresses, colour changes or even melting. nability and dimensional stability. Compared to metals, however, the higher coefficient of thermal Therefore: expansion, lower stiffness and higher elasticity • Tools must be kept sharp and smooth at all times (ground cutting edges), as well as eventual swelling due to moisture • Feed rates should be as high as possible, absorption (mainly with nylons) and possible • Tools must have sufficient clearance so that the cutting edge only comes in deformations caused by internal stress-relieving contact with the plastic material, during and after machining, generally result in • A good swarf removal from the tool must be assured, greater difficulty maintaining tight tolerances • Coolants should be applied for operations where plenty of heat is generated during and after machining. A good rule of (e.g. drilling). www.quadrantplastics.com 3
- 4. When machining Quadrant stock shapes, remember... • Thermal expansion is up to 20 times greater with plastics than with metals. GETTING STARTED • Plastics lose heat more slowly than metals, so avoid localized overheating. • As engineering plastics are not as rigid • Softening (and melting) temperatures of plastics are much lower than those of as metals, it is essential to support metals. the work adequately during machining • Plastics are much more elastic than metals. in order to prevent deflection or deformation. • High speed steel tools work well with Because of these differences, you may wish to experiment with fixtures, tool many plastics. materials, angles, speeds and feed rates to obtain optimum results. • For long runs, use tungsten carbide, ceramic or polycrystalline diamond tooling. • Polycrystalline diamond tooling pro- vides optimum surface finish when machining celazole pbi or torlon pai. ® ® 4 You inspire … we materialize®
- 5. Coolants • Exept for drilling and parting, coolants are not typically necessary for thermoplastic machining operations. • Keeping the cutting area cool generally improves surface finish and tolerances. • When coolants are required, water-soluble coolants generally do very well. They should, however, not be used when machi- ning amorphous thermoplastics, such as PC 1000, RADEL® PPSU 1000, ULTEM® PEI 1000, PSU 1000 and SEMITRON® ESd 410C, because these materials are susceptible to environmental stress-cracking. The most suitable coolants for these materials are pure water or compressed air. • When the use of water-soluble coolants or general purpose petroleum based cutting fluids cannot be avoided during the machining of amorphous thermoplastics (e.g. during drilling of large diameters and/or deep holes or during tapping operations), the parts should immediately after machining be thoroughly cleaned with isopropyl alcohol first and rinsed with pure water afterwards in order to reduce the risk of stress-cracking. www.quadrantplastics.com 5
- 6. Annealing Quadrant Engineering Plastic Products’ stock shapes are annealed using a proprietary stress-relieving cycle to minimise any internal stresses that may result from the manufacturing process. This annealing procedure generally assures optimum dimensional stability during and after machining. However, when machining parts that have to meet stringent requirements with respect to dimensional stability (tolerances, distortion, warpage,...) and/or when machining causes asymmetric and/or heavy section changes, it is recommended to apply an intermediate annealing procedure after pre-machining and prior to final machining of the part. Annealing can be done in an air or preferably a nitrogen circulating oven, or in an oil bath. 6 You inspire … we materialize®
- 7. Recommended annealing T1: heat-up time (heating rate: 10 – 20°C/hour) T2: hold-time (depends on the wall thickness: TH 10 minutes per mm part thickness) T3: cool-down time (cooling rate: 5 – 10°C/hour) T4: additional time required to establish normal (1) Temperature in the centre of the plastic part room temperature (depends on the wall thickness: 3 minutes per mm part thickness) (2) Oven or oil temperature TIPS FOR ANNEALING • When pre-machining, leave enough oversize to allow machining to final sizes after annealing. • Fixturing parts to desired shape or flatness during the entire annealing cycle often proves advantageous. • Do not unfixture until parts have completed entire Time annealing cycle and are cool to the touch. RT • Make sure that temperatures are uniform and within T1 T2 T3 T4 +/- 3°C all over the oven or the oil bath at all times during the annealing cycle. RT : room temperature - TH : hold-temperature • Do not take short-cuts. www.quadrantplastics.com 7
- 8. Annealing guidelines Materials Heat up Hold temperature Hold-time (T2) Cool Down Environment(*) PA 10-20 °C/h 150°C 10 min/mm 5-10°C/h air, nitrogen or oil POM 10-20 °C/h 150°C 10 min/mm 5-10°C/h air, nitrogen or oil PET 10-20 °C/h 150°C 10 min/mm 5-10°C/h air, nitrogen or oil PE-(U)HMW 10-20 °C/h 80°C 10 min/mm 5-10°C/h air, nitrogen or oil PC 10-20 °C/h 130°C 10 min/mm 5-10°C/h air or nitrogen PEEK 10-20 °C/h 250°C 10 min/mm 5-10°C/h air, nitrogen or oil PPS 10-20 °C/h 200°C 10 min/mm 5-10°C/h air, nitrogen or oil PPSU 10-20 °C/h 200°C 10 min/mm 5-10°C/h air or nitrogen PEI 10-20 °C/h 200°C 10 min/mm 5-10°C/h air or nitrogen PSU 10-20 °C/h 170°C 10 min/mm 5-10°C/h air or nitrogen PVDF 10-20 °C/h 140°C 10 min/mm 5-10°C/h air, nitrogen or oil (*): when annealing in air, a more or less pronounced colour change of the outer surface is to be expected (particularly with nylons) – the thin oxidised surface-layer involved, however, is most of the time removed during further machining operations. 8 You inspire … we materialize®
- 9. Machinability Relative Machinability (1 to 6 ; 1 = easiest) 1 2 3 4 5 6 1. TIVAR / ERTACETAL 2. ERTALON & NYLATRON GRADES / SYMALIT PVDF 1000 / FLUOROSINT 207 & 500 3. ERTALYTE / ERTALYTE TX / KETRON PEEK-1000 / TORLON 4203 & 4503 PAI / PC 1000 / RADEL PPSU 1000 / ULTEM PEI 1000 / PSU 1000 4. ERTALON 66-GF30 / TECHTRON HPV PPS / KETRON PEEK-HPV / TORLON 4301 & 4501 PAI 5. KETRON PEEK-GF30 / KETRON PEEK-CA30 / TORLON 5530 PAI 6. CELAZOLE PBI www.quadrantplastics.com 9
- 10. Drilling Plastics can build up heat very easily during drilling operations, especially when hole depths are greater than twice the diameter. Therefore a cooling liquid is generally recommended. • Small diameter holes (0.5 - 25 mm diameter) High speed steel twist drills generally work well. In order to improve heat and swarf removal, frequent pull-outs (peck-drilling) are necessary. A slow spiral (low helix) drill will allow for better swarf removal. • Large diameter holes (25 mm diameter and larger) It is advised to use drills with a thinned web (dubbed drill) in order to reduce friction and hence heat generation. Drill large holes stepwise: a bore diameter of 50 mm e.g. should be made by drilling successively with Ø 12 mm and Ø 25 mm, then by expanding the hole further with large diameter drills or with a single point boring tool. 10 You inspire … we materialize®
- 11. For the following materials it is recommended to bore holes in round rods on a lathe, using “insert drills” or a rigid, flat boring tool with its cutting edge perfectly set on centre-height (see drawing on the right). • Rods > 50 mm diameter: CELAZOLE® PBI, TORLON® PAI, KETRON® PEEK-HPV, KETRON® PEEK-GF30, KETRON® PEEK CA30, TECHTRON® HPV PPS and SEMITRON® ESD 410C. • Rods > 100 mm diameter: ERTALON® 66-GF30, ERTALYTE®, ERTALYTE® TX and KETRON® PEEK-1000. • Rods > 200 mm diameter: ERTALON® and NYLATRON®. Note: for these materials, some machinists prefer to heat the stock shapes up to about 120 - 150°C prior to drilling. www.quadrantplastics.com 11
- 12. Drilling Section AB � � B α: relief angle (°) A γ : rake angle (°) φ: top angle (°) � v : cutting speed (m/min) s : feed (mm/rev.) 12 You inspire … we materialize®
- 13. α γ φ s v ERTALON / NYLATRON • TIVAR • SYMALIT PVDF 1000 10-15 3-5 90-120 0.1-0.3 50-100 ERTACETAL • SEMITRON ESd 225 5-10 3-5 90-120 0.1-.03 50-100 ERTALYTE • TORLON 4203 / 4503 PAI 5-10 3-5 90-120 0.1-0.3 50-80 KETRON PEEK-1000 PC 1000 • RADEL PPSU 1000 • ULTEM PEI 1000 • PSU 1000 5-10 3-5 90-120 0.1-0.3 50-100 ERTALON 66-GF30 • TORLON 4301 / 5-10 3-5 90-120 0.1-0.3 50-80 4501 / 5530 PAI • KETRON PEEK-HPV / GF30 / CA30 • TECHTRON HPV PPS • SEMITRON ESd 410C / 520 HR CELAZOLE PBI 5-10 3-5 90-120 0.1-0.3 25-50 FLUOROSINT 207 / 500 • SEMITRON 5-10 3-5 90-120 0.1-0.3 50-100 ESd 500 HR www.quadrantplastics.com 13
- 14. Drilling - Troubleshooting Difficulty Feed Marks or Tapered Burned or Melted Chipping of Difficulty Chatter Spiral Lines on Hole Surface Surfaces Inside Diameter Common 1. Incorrectly 1. Wrong type drill 1. Feed too heavy 1. Too much 1. Feed too heavy Cause sharpened oil clearance 2. Incorrectly 2. Clearance too 2. Drill not 2. Insufficient sharpened oil great 2. Feed too light centered clearance 3. Feed too light 3. Too much rake 3. Drill overhang 3. Drill ground 3. Feed too heavy 4. Web too thick (thin web as too great off-center described) 4. Too much rake (thin web as described) 14 You inspire … we materialize®
- 15. Oversize Undersize Holes Not Rapid Dulling Burr at Cut-off Holes Holes Concentric of Drill 1. Drill ground 1. Dull drill 1. Feed too heavy 1. Dull cut-off tool 1. Feed too light off-center 2. Too much 2. Spindle speed too slow 2. Drill does not 2. Spindle speed 2. Web too thick clearance 3. Drill enters next piece too far pass comple- too fast 3. Insufficient 3. Point angle too tely through 3. Insufficient 4. Cut-off tool leaves nib, which piece clearance small deflects drill lubrication from 4. Feed rate too coolant 5. Web too thick heavy 6. Drill speed too heavy at start 5. Point angle too great 7. Drill not mounted on center 8. Drill not sharpened correctly www.quadrantplastics.com 15
- 16. Sawing Proper clamping of shapes on worktable is required to avoid vibrations and consequent rough cutting or even rupture. SAWING TIPS • Tungsten carbide tipped saw blades wear well and provide optimum surface Band saws, circular saws or reciprocating saws need to have widely spaced finishes ; particularly alternate top bevel teeth, to assure good chip removal. They should have enough set to minimize and triple chip grinds yield smooth cuts the friction between the saw and the work and also to avoid close-in behind with little or no chipping or burrs. the cutting edge, causing excessive heat build-up and even blocking of the saw. IMPORTANT: Reinforced materials such as ERTALON® 66-GF30, TORLON® 4301 PAI, TORLON® 4501 PAI, TORLON® 5503 PAI, KETRON® PEEK-HPV, KETRON® PEEK-GF30, KETRON® PEEK-CA30, TECHTRON® HPV PPS, SEMITRON® ESd 410C and SEMITRON® ESd 520HR are preferably cut with a brand saw which has a tooth pitch of 4 to 6 mm (CELAZOLE® PBI: 2-3 mm). Do not use circular saws, as this usually leads to cracks. 16 You inspire … we materialize®
- 17. Circular saw Circular saw Band saw Band saw (carbide tipped) (carbide tipped) X X tc tc tb tb �c �c �b �b �c X �c X X–X X–X �b �b � c � circular saw : b : band saw � = 10 – 15 α relief � = 10 –: 15 angle (°) γ : rake angle (°) t : pitch (mm) v : cutting speed (m/min) www.quadrantplastics.com 17
- 18. αc γc tc vc αb γb tb vb ERTALON / NYLATRON • TIVAR • 10 - 15 0 - 15 8 - 45 1,000-3,000 25 - 40 0 - 8 4 - 10 50 - 500 SYMALIT PVDF 1000 ERTACETAL • SEMITRON ESd 225 10 - 15 0 - 15 8 - 45 1,000-3,000 25 - 40 0 - 8 4 - 10 50 - 500 ERTALYTE • TORLON 4203 / 4503 PAI 10 - 15 0 - 15 8 - 25 1,000-3,000 25 - 40 0 - 8 4 - 10 50 - 400 KETRON PEEK-1000 PC 1000 • RADEL PPSU 1000 • ULTEM PEI 1000 • PSU 1000 10 - 15 0 - 15 8 - 25 1,000-3,000 25 - 40 0 - 8 4 - 10 50 - 400 ERTALON 66-GF30 • TORLON 4301 / 4501 / 5530 10 - 15 0 - 15 8 - 25 1,000-3,000 25 - 40 0 - 8 4 - 6 50 - 200 4501 / 5530 PAI • KETRON PEEK-HPV / GF30 / CA30 • TECHTRON HPV PPS • SEMITRON ESd 410C / 520 HR CELAZOLE PBI 10 - 15 0 - 15 8 - 25 1,000-3,000 25 - 40 0 - 8 2 - 3 25 - 100 FLUOROSINT 207 / 500 • SEMITRON ESd 500HR 10 - 15 0 - 15 8 - 25 1,000-3,000 25 - 40 0 - 8 4 - 6 50 - 200 18 You inspire … we materialize®
- 19. Milling Two flute end mills, face mills and shell mills with inserts as well as fly cutters can be used for milling thermoplastics. MILLING TIP • Thin workpieces are often fixed Climb milling is recommended to help reduce heat by dissipating it into the onto the work table by means of chip, and melting and poor surface finishes are minimized. suction plates or double-sided adhesive tape. α α: relief angle (°) γ : rake angle (°) v : cutting speed (m/min) s : feed (mm/tooth) γ www.quadrantplastics.com 19
- 20. Climb Milling vs. Conventional Milling CUTTER CUTTER CUTTER CUTTER ROTATION ROTATIONROTATION ROTATION vs. TABLE FEED TABLE FEED TABLE FEED TABLE FEED CLIMB MILLING CLIMB MILLING CONVENTIONAL MILLING CONVENTIONAL MILLING 20 You inspire … we materialize®
- 21. Turning Typical turning tool with tungsten carbide insert TURNING TIP • The continuous chip stream pro- 5° duced when turning and boring many thermoplastics can be handled well 5° using a compressed air powered suc- tion system (directly disposing the swarf Insert onto a container), in this way avoiding the chip wrapping around the chuck, the tool or the workpiece. 11° 3°30' www.quadrantplastics.com 21
- 22. Turning & Boring Troubleshooting Difficulty Cracking or Melted Rough Burrs at Edge Difficulty Chipping of Chatter Surface Finish of Cut Corners Common 1. Tool dull or 1. Feed too 1. No chamfer 1. Too much positive 1. Too much Cause heel rubbing heavy provided at sharp rake on tool nose radius on 2. Insufficient 2. Incorrect corners 2. Tool not eased tool side clearance clearance 2. Dull tool into cut (tool sud- 2. Tool not 3. Feed rate too angles 3. Insufficient side denly hits work) mounted slow 3. Sharp point clearance 3. Dull tool solidly 4. Spindle speed on tool (slight 4. Lead angle not 4. Tool mounted 3. Material not too fast nose radius provided on tool below center supported required) (tool should ease properly 4. Tool not out of cut gradu- 4. Depth of cut mounted on ally, not suddenly) too heavy center (use 2 cuts) 22 You inspire … we materialize®
- 23. Parting (Cutting-off) - Troubleshooting Difficulty Concave or Nibs orBurrs Burns on Melted Rough Spiral Difficulty Convex at Cut-off Outside Surface Finish Marks Surfaces Point Diameter Common 1. Dull tool 1. Feed too 1. Tool rubs 1. Point angle not 1. Point angle 1. No chamfer Cause heavy during its great enough not applied before 2. Insufficient side 2. Tool retreat 2. Tool not great enough cut-off clearance improperly 2. Burr on perpendicular 2. Dull tool 2. Dull tool 3. Insufficient sharpened point of to spindle 3. Feed too coolant tool 3. Tool deflecting heavy supply 4. Feed too heavy 5. Tool mounted above or below center www.quadrantplastics.com 23
- 24. Turning Section AB � � g A r = 0.5 – 1 mm B α: side relief angle (°) γ : rake angle (°) η: side cutting edge angle (°) v : cutting speed (m/min) s : feed (mm/rev.) 24 You inspire … we materialize®
- 25. α γ η s v ERTALON / NYLATRON • TIVAR • SYMALIT PVDF 1000 5-15 0-10 0-45 0.05-0.5 200-500 ERTACETAL • SEMITRON ESd 225 5-15 0-10 0-45 0.05-.05 200-500 ERTALYTE • TORLON 4203 / 4503 PAI 5-15 0-10 0-45 0.05-0.5 200-400 KETRON PEEK-100 PC 1000 • RADEL PPSU 1000 • ULTEM PEI 1000 • PSU 1000 5-15 0-10 0-45 0.05-0.4 200-400 ERTALON 66-GF30 • TORLON 4301 / 5-15 0-10 0-45 0.05-0.3 100-200 4501 / 5530 PAI • KETRON PEEK-HPV / GF30 / CA30 • TECHTRON HPV PPS • SEMITRON ESd 410C / 520 HR CELAZOLE PBI 5-10 3-5 0-45 0.05-0.2 25-100 FLUOROSINT 207 / 500 • SEMITRON 8-12 0-5 0-45 0.08-0.4 150-400 ESd 500 HR www.quadrantplastics.com 25
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- 28. Regional Headquarters EUROPE NORTH AMERICA ASIA-PACIFIC Quadrant EPP AG Quadrant EPP USA, Inc. Quadrant EPP Asia Pacific Ltd Hardstrasse 5 2120 Fairmont Avenue 108 Tai To Tsuen, Ping Shan CH-5600 Lenzburg PO Box 14235 - Reading, PA 19612-4235 Yuen Long - N.T. Hong Kong Tel +41 (0) 62 8858409 Tel 800 366 0300 / +1 610 320 6600 Tel +852 (0) 24702683 Fax +41 (0) 62 8858181 Fax 800 366 0301 / +1 610 320 6868 Fax +852 (0) 24789966 e-mail: europe.epp@qplas.com e-mail: americas.epp@qplas.com e-mail: asia.epp@qplas.com All statements, technical information and recommendations contained in this publication are presented in good faith, based upon tests believed to be reliable and practical field experience. The reader is cautioned, however, that Quadrant Engineering Plastic Products does not guarantee the accuracy or completeness of this information and it is the customer’s responsibility to determine the suitability of Quadrant’s products in any given application. ERTALON®, NYLATRON®, ERTACETAL®, ERTALYTE®, TIVAR®, KETRON®, TECHTRON®, SYMALIT® and FLUOROSINT® are registered trademarks of the Quadrant Group. TORLON® and RADEL® are registered trademarks of Solvay Advanced Polymers. ULTEM® is a registered trademark of GE Plastics. CELAZOLE® is a registered trademark of PBI Performance Products Inc. The guide was created by Quadrant Engineering Plastic Products. Design and content are protected by copyright law. © 2006 Quadrant Engineering Plastic Products Visit our website for additional information: www.quadrantplastics.com