Induction Forming Seminar


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Detailed presentation on the fundamentals of using induction heating to form tips on polymer tubes.

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Induction Forming Seminar

  1. 1.
  2. 2. PlasticWeld Systems Precision Catheter Manufacturing Equipment <ul><li>Introduction To PlasticWeld </li></ul><ul><li>HPS Series Equipment & Options </li></ul><ul><li>Principle of Operation of Induction Generators </li></ul><ul><li>Coil Design & Theory </li></ul><ul><li>Die Configuration & Heat Application Theory </li></ul><ul><li>Coil/Die Placement </li></ul><ul><li>Tipping Die Material </li></ul><ul><li>Tipping Die Maintenance </li></ul>
  3. 3. Introduction to PlasticWeld Systems, Inc. <ul><li>PlasticWeld HPS-10 catheter tipping equipment </li></ul><ul><li>Provides a high quality, full-featured machine for the accurate forming of catheter tubing distal tips. </li></ul><ul><li>Different versions: </li></ul><ul><ul><li>Tip only </li></ul></ul><ul><ul><li>Tip and eye-form </li></ul></ul><ul><ul><li>Tip and drill </li></ul></ul><ul><ul><li>Tube bonding </li></ul></ul><ul><ul><li>Plus many other combinations </li></ul></ul>
  4. 4. PlasticWeld Systems HPS Lineup <ul><li>Manual HPS-10 Lab/R&D </li></ul><ul><li>HPS-10 Single Pneumatic </li></ul><ul><li>HPS-10 Single Stepper </li></ul><ul><li>HPS-10 Double Pneumatic </li></ul><ul><li>HPS-10 Double Independent </li></ul><ul><li>HPS-10 Double Stepper </li></ul><ul><li>HPS-10 Tip & Eyeform </li></ul><ul><li>HPS-10 Tip & Drill </li></ul><ul><li>HPS-10 Slope Front </li></ul><ul><li>HPS-10 Remote </li></ul><ul><li>HPS-10 Induction Eyeformer </li></ul>
  5. 5. <ul><li>Principle of Operation of Induction Generators </li></ul>
  6. 6. Principle of Operation of Induction Generators <ul><li>Reasons to Consider Induction Heating </li></ul><ul><li>Fast : >2000° F in <1 second </li></ul><ul><li>Precision Heating </li></ul><ul><ul><li>Heat where you want it </li></ul></ul><ul><li>Repeatable </li></ul><ul><ul><li>Excellent process quality </li></ul></ul><ul><ul><li>Reduces Scrap </li></ul></ul><ul><li>Instant On/Instant Off </li></ul><ul><ul><li>Cell or JIT production </li></ul></ul><ul><ul><li>Reduce WIP </li></ul></ul><ul><li>Energy Efficient </li></ul><ul><ul><li>Heat when you need it </li></ul></ul><ul><li>High Production Rates </li></ul><ul><ul><li>Short heating times </li></ul></ul><ul><li>Environmentally Friendly </li></ul><ul><ul><li>No exhaust gases </li></ul></ul>
  7. 7. <ul><li>What is Induction Heating? </li></ul><ul><li>Resistance Heating </li></ul><ul><li>Heated material must be a conductor </li></ul><ul><li>Non Contact </li></ul><ul><li>Produces heat in the part </li></ul><ul><ul><li>Where you want it </li></ul></ul><ul><ul><li>When you want it </li></ul></ul><ul><ul><li>With no contact </li></ul></ul><ul><ul><li>Fast cycle time </li></ul></ul>Principle of Operation of Induction Generators
  8. 8. <ul><li>Induction energy generates heat within a metal part. </li></ul><ul><li>Any electrical conductor will respond to heating by electromagnetic induction. </li></ul><ul><li>Heat is created by eddy currents in the part and the magnetic properties of the alloy (called Hysteresis). </li></ul><ul><li>A non-magnetic alloy will only heat by eddy currents, and is therefore less efficient than magnetic alloys. </li></ul><ul><li>As alternating current from the generator flows through the coil, a rapidly alternating magnetic field surrounds it. </li></ul><ul><ul><li>Strength is determined by the amount of the current flowing in the coil. </li></ul></ul>Principle of Operation of Induction Generators
  9. 9. <ul><li>The part to be heated is positioned inside the induction coil. </li></ul><ul><li>The magnetic field created by the current flowing in the coil will induce an electric potential on the part that is located inside the coil. </li></ul><ul><li>The part is essentially a closed circuit and the induced potential (voltage) causes current to flow within the part. </li></ul><ul><li>The resistance of the part to the flow of the induced current causes the heating action. </li></ul>Principle of Operation of Induction Generators
  10. 10. <ul><li>Heating pattern is determined by: </li></ul><ul><ul><li>The shape and number of turns in the coil </li></ul></ul><ul><ul><li>The frequency of the generator </li></ul></ul><ul><ul><li>The alternating power input </li></ul></ul><ul><ul><li>The size of the work piece </li></ul></ul>Principle of Operation of Induction Generators
  11. 11. Principle of Operation of Induction Generators
  12. 12. Principle of Operation of Induction Generators Coil cross-section Flux field
  13. 13. Principle of Operation of Induction Generators
  14. 14. Principle of Operation of Induction Generators More heat Less heat
  15. 15. <ul><li>The rate at which the part heats, depends on: </li></ul><ul><ul><li>The strength of the magnetic field to which the part is exposed </li></ul></ul><ul><ul><li>The resulting induced currents and the resistance to their flow. </li></ul></ul>Principle of Operation of Induction Generators
  16. 16. <ul><li>Magnetic Material has Greater Skin Effect </li></ul><ul><li>Higher Permeability Materials have Greater Skin Effect </li></ul><ul><li>When compared to a round bar of non-magnetic material, a round bar of magnetic material with the same dimensions, coil, and coil current will have: </li></ul><ul><ul><li>Greater Magnetic Flux Density </li></ul></ul><ul><ul><li>Greater Change of Flux in Outer Sleeve </li></ul></ul><ul><ul><li>Greater Current in Outer Sleeve </li></ul></ul><ul><ul><li>Greater Power in Outer Sleeve </li></ul></ul><ul><ul><li>Lower Currents in Inner Sleeves </li></ul></ul>Principle of Operation of Induction Generators
  17. 17. <ul><li>Frequency Effect on Depth Penetration </li></ul><ul><li>Temperature 68°F 68°F 68°F </li></ul><ul><li>ρ Resistivity 5.0 5.0 5.0 </li></ul><ul><li>µ Permeability 1 1 1 </li></ul><ul><li>ƒ Frequency 50 kHz 200 kHz 400 kHz </li></ul><ul><li>Depth of Penetration .035” .014” .012” </li></ul><ul><li>Higher frequencies produce shallow heating and lower frequencies will produce deeper heating </li></ul>Principle of Operation of Induction Generators
  18. 18. Principle of Operation of Induction Generators Shows some solid state components used in the HPS-10 and MK-25 generators. The IGBT as used in the MK-25 functions in the lower frequency range whereas the MOSFET transistor is used in the HPS-10 so we can use the high frequency range.
  19. 19. <ul><li>Coil Design and Theory </li></ul>
  20. 20. <ul><li>Basic Points to consider: </li></ul><ul><li>Success is directly dependant on proper design of the Inductors (work coils). </li></ul><ul><li>The inductor coil itself is only a part of the generator output system </li></ul><ul><li>The same principles of design must be applied to the leads which connect the coil to the output terminals of the generator or remote heating station. </li></ul>Coil Design & Theory
  21. 21. <ul><li>Inductors for high frequency induction heating </li></ul><ul><li>Usually referred to as heating coils </li></ul><ul><li>Can be made in a large variety of types and styles </li></ul><ul><ul><li>Depends on the shape of the metal surface to be heated </li></ul></ul><ul><li>Their design must follow certain principles to achieve maximum efficiency. </li></ul>Coil Design & Theory
  22. 22. Various Coil Configurations Coil Design & Theory
  23. 23. <ul><li>The induction coil quickly raises the temperature of a work piece by means of a high frequency current which passes through the coil, as shown in Fig. 1. </li></ul>Coil Design & Theory
  24. 24. <ul><li>Induction coils may be either of multi-turn design, or in the form of a single-turn coil as shown in Fig. 2, the latter often being termed a solid- inductor. </li></ul><ul><li>In either case, copper is invariably used in their construction, and cooling by means of water is absolutely essential . </li></ul>Coil Design & Theory
  25. 25. <ul><li>The path of magnetic flux in cylindrical coils is shown in Fig. 3. </li></ul><ul><li>The direction of the magnetic lines is determined by the direction of the current as it flows through the inductor coil. </li></ul>Coil Design & Theory
  26. 26. <ul><li>Heating of metal parts is the result of internal energy losses within the material being treated, which causes the temperature to rise. </li></ul>Coil Design & Theory
  27. 27. <ul><li>Magnetic fields occur in the area surrounding the coil, and are stronger next to it than at any distance away from it </li></ul><ul><li>Placing the work piece close to the coil maximizes the heat energy generated. </li></ul><ul><li>The strength of the field varies inversely with the square of the distance between the work and the coil. </li></ul><ul><ul><li>distance between coil and work piece will have a direct relation to the amount of heat generated in a work piece. </li></ul></ul>Coil Design & Theory
  28. 28. <ul><li>Fig. 5. shows two single-turn coils. One has a close coupling and the other a loose coupling. </li></ul><ul><li>Usually, a close coupling from 3/32&quot; to 1/8&quot; will be satisfactory for outer surface heating where a thin skin heat is desired. </li></ul><ul><li>A wider coupling will require more time to generate the heat and its depth will be greater. </li></ul>Coil Design & Theory
  29. 29. <ul><li>When multi-turn coils are closely coupled to a workpiece, there is a tendency for the eddy-currents to create a heat pattern matching the coil’s helix. </li></ul><ul><li>The wider the pitch of the coil, the more pronounced this pattern will be. </li></ul><ul><li>When the coil is more loosely coupled, that is at a greater distance from the surface to be heated, the stream of eddy currents spreads over a wider area. </li></ul>Coil Design & Theory
  30. 30. <ul><li>A wide variety of shapes is possible when making multi-turn coils of copper tubing. </li></ul><ul><li>The most common is a cylindrical coil, which is suited to surface heating of shafts and round parts. </li></ul>Coil Design & Theory
  31. 31. <ul><li>The pancake coil shown below is used for heating flat surfaces. </li></ul><ul><li>The spiral-helical coil shown above is used for heating conical surfaces. </li></ul>Coil Design & Theory
  32. 32. <ul><li>Copper tube coils are usually made of tubing, ranging from 1/8 &quot; to 3/8 &quot; in diameter. </li></ul><ul><li>The 1/8&quot; size should be used very sparingly, however, because the flow of cooling water is likely to be too small to prevent over-heating. </li></ul>Coil Design & Theory
  33. 33. <ul><li>Round copper tubing can be used for many types of coils, as shown in “A”, </li></ul><ul><li>It is preferable to flatten the tubing as illustrated in “B”. </li></ul>Coil Design & Theory
  34. 34. <ul><li>Another very practical form is the square or rectangular shape shown in “C”. </li></ul><ul><li>It also is possible to use a larger diameter tubing, such as 5/8&quot; or 3/4 &quot;. as shown at “D”, and to produce a flat coil similar to a solid Inductor previously mentioned. </li></ul>Coil Design & Theory
  35. 35. <ul><li>SOLID-TYPE induction coils are made of rolled copper plate and can be arranged for single or multiple operations. </li></ul>Coil Design & Theory
  36. 36. <ul><li>The coil shown in Fig. 14 is made of a thick copper plate, bored to suit the diameter of the part. Two connecting blocks are brazed to this plate, then the plate is sawed out, as shown, so the high-frequency current will follow the path of the arrows-coming in at one block, and going out at the other. </li></ul>Coil Design & Theory
  37. 37. <ul><li>Usually, when heating a tapered surface, the coil is made to conform with the taper, although exceptions may be considered as in Fig 19, </li></ul>Coil Design & Theory
  38. 38. Die Configuration & Heat Application Theory
  39. 39. Die Configuration & Heat Application Theory <ul><li>Tipping Conditions – Heat Sink </li></ul>
  40. 40. <ul><li>The tube acts as a heat sink when it is pushed too far into the die. </li></ul>Die Configuration & Heat Application Theory
  41. 41. <ul><li>Tube not pushed far enough into the die. </li></ul>Die Configuration & Heat Application Theory
  42. 42. Die Configuration & Heat Application Theory <ul><li>Too much heat causes material degradation. </li></ul>
  43. 43. Die Configuration & Heat Application Theory <ul><li>Deposits on inside of die. </li></ul>
  44. 44. Coil/Die Placement
  45. 45. Coil/Die Placement
  46. 46. Coil/Die Placement
  47. 47. Coil/Die Placement
  48. 48. <ul><li>Coil location is adjusted by sliding entire actuator assembly left or right until proper coil distance is achieved. </li></ul>Coil/Die Placement
  49. 49. <ul><li>The slide adjustment system contains X and Y dovetail assemblies for easy adjustment of coil location. </li></ul>Coil/Die Placement
  50. 50. Tipping Die Material
  51. 51. Tipping Die Material <ul><li>300 Series Stainless – Non-Magnetic </li></ul><ul><ul><li>Heats by Eddy Current effect only </li></ul></ul><ul><li>400 Series Stainless – Magnetic </li></ul><ul><ul><li>Heats by Hysteresis and Eddy Current effect </li></ul></ul><ul><ul><li>400 Series Standard Grade Stainless - can contain impurities. </li></ul></ul><ul><li>420 Mold Grade Stainless - impurities are removed. </li></ul>
  52. 52. Tipping Die Material
  53. 53. Tipping Die Material
  54. 54. Tipping Die Material
  55. 55. Tipping Die Material
  56. 56. <ul><li>Formed Nickel Dies </li></ul>Tipping Die Material
  57. 57. Die Maintenance
  58. 58. Die Maintenance <ul><li>TIPPING DIE CLEANING INSTRUCTIONS: </li></ul><ul><li>Follow proper lockdown/tag out procedure before removing die from die holder. </li></ul><ul><li>DO NOT insert any metal object in an attempt to clean dies or remove stuck material as this will damage or possibly destroy the tool. </li></ul><ul><li>Dies should only be cleaned as follows: </li></ul><ul><li>Materials needed: </li></ul><ul><ul><li>100,000 Grit Luster-Lap Diamond Lapping Compound, Light Concentrations found in McMaster-Carr Supply part number 4776A48. </li></ul></ul><ul><ul><li>Wooden dowel turned down to approximately 10% under the ID of the tipping die with a radiused end or tip. See example below. </li></ul></ul>
  59. 59. <ul><li>For Open Tip Dies – remove the pin. Place die in a lathe and spin @ approximately 3,000 RPM. </li></ul><ul><li>Put a small amount of polishing compound on the tip of the stick, insert into spinning die until it touches the bottom. Slowly and gently move the stick in and out of the die. </li></ul><ul><li>NOTE: DO NOT APPLY EXCESSIVE PRESSURE AS THIS MAY DEFORM THE DIE. </li></ul><ul><li>Periodically check remove the die and check the ID under a lighted scope to view the progress of the cleaning. </li></ul><ul><li>Any questions or concerns, contact PlasticWeld Systems, Inc. at 716-778-7691. </li></ul>Die Maintenance
  60. 60. Die Maintenance
  61. 61. <ul><li>PlasticWeld Systems, Inc. </li></ul><ul><li>3600 Coomer Road </li></ul><ul><li>Newfane, NY 14108 </li></ul><ul><li>USA </li></ul><ul><li>Ph. 716-778-7691 </li></ul><ul><li>Fax 716-778-5671 </li></ul><ul><li>Email: [email_address] </li></ul><ul><li>-or- </li></ul><ul><li> </li></ul>