ADVANCE INJECTION MOULD DESIGN

1. ADVANCE INJECTION MOULD DESIGN 01 CORPORATE TRAINING AND PLANNING

2. SPLIT MOULD 02 CORPORATE TRAINING AND PLANNING

3. It is required for components incorporates a recess or projection right angle to the line of draw, to relieve the undercut before the moulding is removed. A moulding which has a recess or projection is termed as undercut moulding. The undercut may be external, internal, local part of the component. Two or more parts of the cavity closed together in a chase bolster by using locking heels during injection. SPLIT MOULD 03 CORPORATE TRAINING AND PLANNING

4. Fig: 1.1 Fig: 1.2 04 CORPORATE TRAINING AND PLANNING

5. VISIBLE LINE ON MOULDING • Parting line: The line formed on the molding surface where the core and cavity closed together. • Joint Line: The line formed on the molding surface where the splits (side cores) are closed together. 05 CORPORATE TRAINING AND PLANNING

6. SLIDING SPLITS • The splits are positioned in guides on a flat mould plate are actuated by mechanical or hydraulic system and those are held together by locking heels which project on the other mould half. • The splits are possible to mount on either the moving or fixed mould plate. 06 CORPORATE TRAINING AND PLANNING

7. Fig: 1.3 Fig: 1.4 07 CORPORATE TRAINING AND PLANNING

8. GUIDING AND RETENTION OF SPLITS - SLIDING FIT Fig: 1.5 Fig: 1.6 08 CORPORATE TRAINING AND PLANNING

9. Fig: 1.8 Fig: 1.7 09 CORPORATE TRAINING AND PLANNING

10. DESIGN CONSIDERATION OF SPLIT MOULD • The side movement should ensure the split halves always come together in the same plane. • In split mould all the parts should have enough strength to withstand the force applied to the splits by the operating system. • It should allow smooth movements of splits. 10 CORPORATE TRAINING AND PLANNING

11. SPLIT DESIGN CONSTRAINTS • Amount of splits movement and delay period required. • Ease with which the molding can be removed. • Whether a short or long production run is required. • Whether the available machines are programmed for ancillary cylinder control. • Whether molding inserts are to be incorporated. 11 CORPORATE TRAINING AND PLANNING

12. SPLIT MOULD ACTUATION METHODS • Finger cam actuationmethod • Dog-leg cam actuation method • Cam track actuation method • Hydraulic actuation method • 5. Angled-lift splits • 6. Spring actuation system 12 CORPORATE TRAINING AND PLANNING

13. 1.FINGER CAM ACTUATION Sleeve ejector pin Split in open condition Split in closed condition Fig: 1.9 Fig: 1.10 13 CORPORATE TRAINING AND PLANNING

14. FINGER CAM ACTUATION MOULD FOR CAP COMPONENT CORPORATE TRAINING AND PLANNING

15. FINGER CAM MOULD FOR LEDHOLDER CORPORATE TRAINING AND PLANNING

16. FINGER CAM PIN • Hardened, circular steel pins, termed finger cams are • mounted at an angle in the fixed mould plate. • Length and angle of the finger cam determine the distance traversed by each split across the face of the mould plate. 14 CORPORATE TRAINING AND PLANNING

17. FINGER CAM PIN M = splits movement  = Angle of finger cam, 10-25 L = working length of finger cam C = clearance (0.75mm) Fig: 1.11 15 CORPORATE TRAINING AND PLANNING

18. CALCULATION The finger cam movement can be computed by the Formula M = (L sin ) – (C / cos ) If the required movement is known, the following formula used to determine the finger cam length. L = (M / sin ) + (2C / sin 2) Where, M = splits movements,  = Angle of finger cam, 10-25 L = working length of finger cam C = clearance (0.75mm) Cam diameter is usually 13 mm. 16 CORPORATE TRAINING AND PLANNING

19. 2. DOG - LEG CAM ACTUATION This actuation system is used where a more splits delay time is required compare to finger cam actuation method. 17 CORPORATE TRAINING AND PLANNING

20. DOG-LEG CAM Fig: 1.12 18 CORPORATE TRAINING AND PLANNING

21. DOG-LEG CAM ACTUATED MOULD Split in open condition Split in closed condition Fig: 1.14 Fig: 1.13 19 CORPORATE TRAINING AND PLANNING

22. DOG LEG CAM ACTUATED SPLIT MOULD M = movement of each split, La= angled length of cam, Ls = straight length of cam,  = Cam angle, C = clearance, D = delay, e = length of straight portion of the hole. 20 Fig: 1.15 CORPORATE TRAINING AND PLANNING

23. CALCULATION Formula for calculating the opening movement, the length of cam, and the delay period M = La tan  - C La = (M + C)/ tan  D = (Ls – e) + (C/tan ) Where M = movement of each split, La= angled length of cam, Ls = straight length of cam,  = Cam angle, C = clearance, D = delay, e = length of straight portion of the hole. 21 CORPORATE TRAINING AND PLANNING

24. 3. CAM TRACK ACTUATION • This type of actuation system is used for components having under cut which requires more delay period • Due to external fitment of cam track the mold actuation system becomes simpler and mold cost is reduced. • The cam track is machined into a steel plate attached to the fixed mould half. • A boss fitted to both sides of the split runs in this cam track. • The movement of the splits accurately controlled by specific cam track design . 22 CORPORATE TRAINING AND PLANNING

25. CAM TRACK PLATE Fig: 1.17 Fig: 1.16 23 CORPORATE TRAINING AND PLANNING

26. SLIDING SPLIT MOLD (CAM TRACK PLATE ACTUATED) Fig: 1.18 24 CORPORATE TRAINING AND PLANNING

27. ASSEMBLY OF CAM TRACK ACTUATION MOLD IN CLOSED POSITION Fig: 1.19 25 CORPORATE TRAINING AND PLANNING

28. CAM TRACK M = movement of each split, La= angled length of cam track, = cam track angle, C = clearance, D = delay, R = radius of boss Fig: 1.20 26 CORPORATE TRAINING AND PLANNING

29. CALCULATION M = La tan  - C La = (M + C) / tan  D = Ls + C/ tan  + r ( 1/tan  - 1/sin  ) M = movement of each split, La= angled length of cam track,  = cam track angle, C = clearance, D = delay, R = radius of boss 27 CORPORATE TRAINING AND PLANNING

30. 4. HYDRAULIC ACTUATION The splits are actuated by hydraulic system. It is independently opening movement of the mould. The splits can be operated automatically at any specific time by the operating program of the machine ADVANTAGES • Cycle time less • Large delay movements and large split movements • can be achieved 28 CORPORATE TRAINING AND PLANNING

31. DISADVANTAGES • The mould is more bulky as compared with the other designs • Mould setting more difficult and the hydraulic system has to be connected each time the mould is set up. 29 CORPORATE TRAINING AND PLANNING

32. HYDRAULIC ACTUATION OF SPLITS Fig: 1.21 30 CORPORATE TRAINING AND PLANNING

33. ANGLED-LIFT SPLITS • In this method the splits are mounted in a chase-bolster, which forms part of the moving half of the mould. • The splits are moving outward with an angular motion which relieve the undercut portion of the molding and retraction of the split alignment is controlled by using spring actuation or cam track actuation 31 CORPORATE TRAINING AND PLANNING

34. ANGLED LIFT SPLITS DIAGRAM Fig: 1.22 Fig: 1.23 32 CORPORATE TRAINING AND PLANNING

35. TYPES OF ANGLED LIFT SYSTEMS • Angled guide dowel actuating system • Cam track actuating system • Spring actuation. 33 CORPORATE TRAINING AND PLANNING

36. ANGLED GUIDE DOWEL ACTUATING SYSTEM • The Guide dowels are fitted at an angle to the underside of each split which passes through holes machined at an angle in the chase-bolster. • When the ejector system is actuated, the relative movement between the ejector plate and the chase-bolster causes the guide dowels to move forward at an angle corresponding to the splits which opens. 34 CORPORATE TRAINING AND PLANNING

37. ANGLED GUIDE DOWEL ACTUATION Split in closed condition Fig: 1.24 35 CORPORATE TRAINING AND PLANNING

38. Split in open condition = Guide dowel angle. Fig: 1.25 36 CORPORATE TRAINING AND PLANNING

39. The convenient angle for the guide dowel is 10 it may be increased if large opening movement is required. The actual opening movement of each split calculated by the following formula. M = E tan  E = effective ejector plate movement, = Guide dowel angle. 37 CORPORATE TRAINING AND PLANNING

40. CAM TRACK ACTUATING SYSTEM • In this method the opening movement of the splits are controlled by a cam track. When the splits are actuated, studs fitted to each end of the split slide along this cam track. • Actuation of the splits is by means of pin ejector system. The splits are fitted into an open channel type chase-bolster, which have wear plates. • Studs, screwed into the splits, protrude into the cam track machined in the cam track plate which is attached to the bolster. 38 CORPORATE TRAINING AND PLANNING

41. CAM TRACK ACTUATION Fig: 1.26 39 CORPORATE TRAINING AND PLANNING

42. CALCULATION The opening movement of each split calculating by M = E tan  E = effective ejector plate movement, = Cam track angle, usually 15 40 CORPORATE TRAINING AND PLANNING

43. SPRING ACTUATION • The opening movement of the split depends on the slot provided in the chase bolster and the spring effective expansion length. • This ejection method is suitable for shallow undercut components. • The ejector pin actuates the split, the spring exerts the a force to vertical direction, which maintains contact between the split and the angled wall of the chase-bolster and gives angled movement to the splits. Thus the splits get open. 41 CORPORATE TRAINING AND PLANNING

44. SPRING ACTUATION METHOD Fig: 1.27 42 CORPORATE TRAINING AND PLANNING

45. SPRING ACTUATION SYSTEM • This actuation system is suitable for small straight and angled undercut components. • In this method the compression springs are used to force the splits apart and utilizes the angled faces of the chase bolster to close them. The opening of split movement should be limited so that they will allow to re-enter the chase bolster when the mould is closed. • The splits are mounted on the mould plate and retained by guide strips. Studs project from the base of the splits into a slot machined in the mould plate. The length of this slot therefore controls the opening movement of each split. • A compression spring is fitted between the studs in a link-shaped pocket situated in the lower mould plate. The splits are held closed by the chase bolster. 43 CORPORATE TRAINING AND PLANNING

46. SPRING ACTUATION Fig: 1.28 44 CORPORATE TRAINING AND PLANNING

47. SEQUENCE OF OPERATION • The chase bolster holds the splits during the injection phase. • The compression springs exerts a force to split halves immediately when the mould starts to open. • The stud reaching the end of the slot in the mould plate stops the split movement. • Continued movement of the moving mould half operated the ejector system to release the molding . 45 CORPORATE TRAINING AND PLANNING

48. CALCULATION • The formula for calculating the splits opening movement is • M = ½ H tan  • Where M = movement of each split, Approximately • H = height of locking heel • = angle of locking heel Suitable angle for the locking heel is 20 to 25. 46 CORPORATE TRAINING AND PLANNING

49. SIDE CORES • It is a local core mounted at an angle to the mould axis for forming a hole or recess inside the molding. • This side core prevents the in-line removal of the molding hence, side core must be withdrawn prior to ejection . 47 CORPORATE TRAINING AND PLANNING

50. TYPES OF SIDE CORE Internal Side Core Assembly • The dog-leg cam actuation method • The spring-loaded system External Side Core Assembly • Side cores on the parting surface • Side cores below the parting surface • Angled withdrawal Curved side core 48 CORPORATE TRAINING AND PLANNING