01.Confirming Part Data
1. Is the part 3D/2D data the newest one? Including Part No. & Revision, the Date received, Is it a mirred one or the shrinkage applied?
2. Resin code and the shrinkage: who will supply the shrinkage value? Is the shrinkage correct?
3. The cavitation Number;
4. Is there thick & thin wall thickness? How to deal with it if the sink mark or short shot occurs?
5. Is the draft angle enough?
6. Is there texture/graining? The releasing angle for the texturing area? Texturing number and supplier? The steel is suitable for such texturing or polishing?
7. Is the steel for main cavity/core block and sub insert suitable for the specified mold life or other requirement?
8. Data code & other marking component: location and style;
9. Is there critical tolerance that is difficulty to meet? any solution? Is there deviation tolerance?
10. Are all the items discussed with customer in DFM stage OK?
11. Is there any potential part warp/deflection? Is additional steel stock needed?
12. Is there a mold making manual or general mold requirement supplied by customer and thoroughly understood by mold designer?
13. The potential molding defect? Can be molded? Releasing problem? sink mark? Warp? Deflection? Is the the windage needed?
14. Are there any undercuts? Can it be removed?
15. Are there missing part in a family mold?
16. Is it a capacity mold(repeat) mold? If yes, any lessons learnt from previous mold can be incorporated? Any improvement?
02. The Overall Design,Mold Base and Setting Up
1. Is the part lay out ok?, especially for a family mold and multi cavity mold;
2. Is the moldbase the correct style ? DME,Hasco,LKM or othes?
3. The overall mold size can be settlled in the injection machine specified by customer? Is the mold width less than the horizontal space of press?
4. Is the mold thickness less than the horizontal space of press when loading the mold into press horizontally?
5. Is the moldbase has enough strength?
6. Is the thickness of top clamp plate ok? Especially for a 3 plate mold.
7. What’s the ratio of pocket depth to the thickness of cavity plate?
8. What’s the ratio of pocket depth to the thickness of core plate?
9. Is the thickness of bottom clamp plate ok? Especially for a 3 plate mold.
10. Is there enough screw between top/bottom plate and other plates?
11. Is the diameter and length of leader pin and bushing ok? Especially for a 3 plate mold
12. Is the guided ejection system ok?
13. Is the ejection stroke ok? (the height of spacer block)
14. The aligning and clamping features/components must be used for the mold with complicated parting lines and many shutt offstucture;
15. The leaderpin/bushing must be used between top clamp plate and hot manifold palte for hot runner mold;
16. For the mold with a width over 400mm, a wedge block must be used for securing the cavity & core block in the mold plate(0.50~1.00mm gap is needed in such case);
17. Guided ejection system must be used for the mold with a width over 500mm or mold with a lot of lifter or ejector sleeve;
18. Six or much more number of return pins for the mold with a width over 700mm or the length is over 2 times of width;
19. Is the mold base style or size OK? Can it be settled into the injection machine to be used?
20. Is the mold thickness less than the column space if the mold to be loaded into press along horizontal direction?
21. Is the style and size of locating ring ok?
22. Is the spherical radius of locating ring ok? Is the “O” size ok?
23. For all the 3 plate mold, a value of higher grade must be used for the thickness of top clamp plate must;
24. Is the stripper bold stroke and size ok? Is the spring on it ok?
25. Can the part fall freely in 3 plate mold? Any interference between runner scrach and stripper bolt, return pin or leader pin?
26. Is the design and size of runner locking ping ok?
27. Is the quantity & size of parting lock enough? Is it symmetrical placement?
28. Is there a lifting holes for all the plate over 20kg?
29. Are there any interference when lifting the mold? Is it a balanced lifting?
30. Is the size and location of lifting holes ok?
31. A round clearance between plate and cavity/core block/slide/guide rail/wear plate/heel block must be used;
32. Is the mold datum marked correctly?
33. Is the heat insulation sheet needed? Is there enough screw on it?
34. Is the ejection stroke ok?
35. Is the size and pattern of KO holes correct? Is the coupler ok? Can the mold be koncked out in a balanced way?
36. Is there any other items in the clamp slot?
37. The thickness of clamp slot is ok?(especially for 3 plate mold,hot runner mold);
38. Is there safety strip?
39. Is there pry bar slot? Preferred size: 20x20x10;
40. Is all the spring std. one? The compression ration?
41. No interference between clamp slot, slide, oil cylinder and hoist ring;
42. Is the main bushing vented?
43. All the eye bolt holes should be marked the size;
03.The Shape Forming Component
1. Was the parting line approved by customer or it’s specified by 2D print?
2. Is the parting line between cavity/core,slide/lifter ok?
3. Is the part cosmetics requirement can be met with current P/L?
4. Has the P/L a better machinability? CNC, surface grinding/gun drilling;
5. is the P/L suitable for the design of feeding, cooling and ejection system?
6. Can the part be demolded easily? Is the part be kept with the core mold half?
7. Can the sub insert be replaced and installed easily?
8. Is the splitting of subinsert ok? Are there any poor steel condition/thin steel?
9. Are all the angle of shut off over 2 degree?
10. Are there any area that is difficulty for CNC machining? Such as the side and bottom radius of a deep pocket?
11. Are the main cavity/core block be cleared in non shut off area?
12. Any chamfering or edge blending is missing?
13. Is there enough venting?
14. Is the aligning pad ok? Especially for the mold with a complicated curved p/l;
15. Is the datum for the height dimension needed? Especially for the mold with a complicated curved parting line;
16. Is the sub insert labeled: steel, hardness, I.D or revision No;
17. Is there any interchangeable insert? Is it fully depicted in the design? Is a Poka-Yoke (mistaking-proofing) design used here?
18. is the layout of cooling line in main cavity/core block best solution? Is it enough?
19. Is the securing style of block/subinsert ok? By screw or by step?
20. Is the anti-rotation feature missing for all the round insert/ejector sleeve?
21. The main diameter of core pins/ejector sleeve must be a std. one;
22. Has the removing of material at the bottom of boss feature been done?Any solution if the sink marks here happened?
23. Has the removing of material at the bottom of thick rib been done? Any solution if the sink marks here happened?
24. The poor/thin steel condition of part, is it can be easily made?
25. How much is the min. distance between water line and plastics part? Is it an uniform cooling around whole part?
26. How much is the min. distance between water line and edge of cavity block/ejector ping? Any interference between water line and ejector pin/screw or other component?
27. Is the min. fitting distance between ejector pin and cavity/core block over 15mm?
28. Is the min. distance between ejector pin and edge of cavity/core block over 1.5mm?
29. Is there separated cooling lines around the hot sprue /hot drop?
30. Are there lifting screw holes in the main cavity/core block/bigger insert at parting line side?
31. Is the main cavity/core block/insert marked correctly? Steel, hardness, recycle, data stamp, cavity No.;
32. Was the interchangeable insert labeled on the side of mold?
33. Is the deep rib/boss feature inserted?
34. Is the cooling layout same between each cavity in a multi cavity mold?
35. Is the datum of main cavity/core block missing?
36. Is the thickness of main cavity/core block enough?
37. Is the size and quantity of securing bolt of main cavity/core block ok?
38. Can the main block be easily loaded into mold plate? Is the edge block needed?
39. Is there sharp steel/undercut?
40. Is the shut off angle enough?
41. How much is the min. shut off distance?
04.Feeding & Gating System
1. was the gating style(size, location, quantity) approved by customer?
2. For sub gate(cashew, tunnel, banana), an gate insert should always be tried if possible, especially for abrasive material(with GF additive);
3. Is the size and section shape of runner ok?
4. is the size and shape of cold slug well ok?
5. is the main runner extended by 2 times of runner diameter?
6. can a balanced filling be got? Is the position of weld line accepted?
7. How the runner scrap be removed? Falling freely, by hand or by robot;
8. Is the runner lock pin design ok?
9. Is the dimple missing for pin point gate and banana gate?
10. Is the grip feature needed for the runner scrap if it’s removed by robot?
11. Can the cashew gate/banana gate be easily knocked out?
12. Is the runner ground marked?
13. What’s the max. recess distance of sprue into mold plate?
14. Is the size of main runner and branch runner ok? Is the area of section correct?(the sum of branch runner was less than or equal to that of main runner)；
15. Is the size of gate ok?
16. For the transparent part, is there a chance of weld line?
17. Was the gate style and size verified in mold flow analyzing?
18. Is one detailed view of gate offered?
19. Is the gate location opposite to ejector pin, core pin or other small insert?
20. Is the runner lock pin offset by 2mm?
21. Is a filling analysis done for the part?
05. Undercut Releasing System
1. Is the stroke enough?
2. Has slide a good strength?
3. Is there a middle guide rail for slide with a width over 150mm?
4. For slide with a bigger shape forming area, is the heel block supported by mold base?
5. Is there cooling lines in bigger slide?
6. Can the lifter be easily assembled?
7. For the bigger slide at top side, can it be firmly secured at the end of stroke?
8. For the angled block at cavity side, is the angle ok? Is the stroke less than 1/3 of total length?
9. Is there a wear plate? The length of wear plate should be as bigger as possible.
10. The safety switch must be used at the start and end position for all the hydraulic cylinder;
11. Is the stroke of lifter enough?
12. The steel and hardness of component moving against each other must be different, the min. hardness difference is 3 HRC.
13. The design of lifter should try to meet that it can be mounted/dismounted without the removing of mold bottom clamp plate;
14. The coupler of lifter should be the Progressive STD. one if possible；
15. A difference of 2 degree between the lifter rod and lifter head insert is needed for oversized lifter(the head has a bigger angle/2 degree);
16. Cooling lines was needed for oversized lifter;
17. Is the clearance between lifter at the end of stroke and other features of plastics part enough? 3~5mm preferred.
18. The angle of lifter should below 15 degree;
19. Can the slide be secured at the end of stroke?
20. Is the leader pin longer than the angle pin(the leader pin entry the bushing early );
21. Is there a lifting holes for oversized slide?
22. A brass bushing is needed for the lifter with separated rod design;
23. Is a shut off angle at lead in area( it’s preferred to have an angle at both side and top /bottom );
24. Is the clearance between the heel block and mold base enough?
25. Is the guide rail design ok?
26. Is the angle pin design ok? Style and size;
27. Is the wear plate ok?
28. Is there an angle difference of 2 degree between angle pin and the heel block?
29. Is the dog-leg design supported in a slide in 3 plate mold?
30. Is the length of angle pin enough?
31. Is the clearance between angle pin and B plate needed?
32. Is the slide base marked?
33. Is the slide pin marked?
34. Is the heel block marked?
35. Is the guide rail marked?
36. Is the lifting screw needed when the slide and cavity block must be polished together
37. Is there any interference between lifter and waterlines?
38. Is the angle of lifter ok?
39. Is there any interference between lifter and ejector pin?
40. The steel condition of lifter;
41. Try to shorten the lifter and increase the section size;
42. Is there a straight segment design in 2 direction (used as the datum for machining) in the lifter?
43. Is there interference between lifters?
44. Is there undercut along the moving direction of lifter? Removing of material needed?
45. For the inserting design, is the rod design ok?
46. Is the holes for lifter in the mold plate bigger enough?
47. Is the thickness of wear plate a std. one?
48. The length of slide is 2 times of slide height;
49. The lifting screw should be design in the guide rail
50. The 2 guide rails should be used when the length is over 120mm;
06. Ejection System
1. Is the ejection method the best one? By ejector pin, stripper plate, ejector blade, ejector block, ejector sleeve?
2. Can a balanced ejection be got?
3. Is the size of ejector diameter ok?
4. Is the returning spring ok?
5. Guided ejection should always be use, the diameter guide pin is bigger than the return pin;
6. Is the safety switch under the bottom ejector plate missing?
7. Is there a limit block design? Is it needed?
8. Is the recess distance of ejector pin approved by customer?
9. Can the plastics part be fully knocked out?
10. Is an early ejector return system needed?
11. Is the position of ejector pin/sleeve the best one?
12. Is there enough distance between ejector pin and the edge of mold block? >1.5MM;
13. Is there interference between ejector pin and water lines, support pillar, lifter and K.O holes?
14. A stepped ejector pin should be used when the length is over 70times of diameter;
15. Is the air poppet needed for deep round part?
16. Is there interference between ejector sleeve and the K.O holes?
17. Was the coupling component between mold and injection machine approved by customer?
18. Is there ejector pins under the slide? Is a safety pin/early ejector return/safety switch needed?
19. A stepped ejector pin should be used if the diameter is less than 3mm;
20. Is there a lead in chamfer made at the entrance area of all ejector pin/ blade;
21. Is there an anti-rotation design with all ejector pin with a contour tip;
22. Is the clearance for ejector pin ok?
23. Is the thickness of bottom ejector plate enough? Are there enough quantity of screw between both ejector plate ?
07.Supporting System
1. Is the quantity and size of support pillar enough? Is the location of support ok?
2. Try to use a bigger dia. in all the case;
3. Is there interference between support pillar and K.O. holes, ejector pin, sleeve, lifter, stop pin?
4. Is the size and location of stop pin ok?
5. Is the stop pin missing under the return pin, lifter and area with a lot of ejector pin?
6. Is the protecting pillar needed around oil cylinder, slide, hot runner connector?
7. Is mold feet needed?
08. Cooling & Heating System
1. Is the cooling layout the best one? Can a uniform cooling be got?
2. Is the size and quantity of cooling line ok?
3. Is there any interference between water line and other component?
4. Was the size and specification of water fittings, plug, connector approved by customer?
5. Is there enough clearance for water fittings?
6. Try to minimize the using of “O” ring in all the case;
7. Was the size and specification of “O” ring approved by customer?
8. Was the water line labeled correctly? For example, IN_1,OUT_1,….
9. what’s the min. distance between waterline and other items?
10. Is the distance between water lines ok?
11. Is there enough cooling at the small deep area, segment that may warp and web area?
12. Is there cooling lines in oversized slide, lifer and thin long core pins?
13. Is there cooling lines around the hot sprue/drop?
14. Is it possible to control the part warp/deflection by using a different mold temperature?
15. The min. distance between cooling lines and ejector pin, sleeve, insert, screw, angle pin, lifter is over6.5mm;
16. There is no interference between water fittings and hoist ring, clamp slot, the column bar of injection machine;
17. Recessed design should always be used;
18. The outlet should be placed at non operator side in any case;
19. No outlet should be placed top side of mold, especially for hot runner mold and high polish mold;
20. The cooling diagram should be placed at non operator side;
21. Is the min. space between connector ok? >25mm in most case, 31mm preferred.
22. Is there a baffle design? Is it oriented correctly?
23. Is the hot oil to be used? If yes, the correct “O” ring should be used.
24. Can the cooling plug in the moving component, such as, slide, lifter be moved freely without interference?
09. Venting
1. Is there enough venting at the main parting line?
2. Is there the chance of burning/air trap? If it happens, any solution can be done at the mold design stage?
3. Is the deep rib, boss vented?
4. Is the insert vented?
5. Is the ejector pin vented?
6. Is the air poppet needed at the bottom of deep round part ?
7. Is the venting guided to atmosphere?
8. Can the venting design be machined easily?
10. Hot Runner System
1. Was the hot runner supplier, style, specification approved by customer?
2. Is the filling capability ok?
3. Was the heat expansion considered in the key mounting dim of hot sprue and hot drop?
4. The guide pin/bushing was needed between top clamp plate and manifold plate to help the mounting of hot runner system;
5. Is spare valve pin needed?
6. Should the gating tip be inserted?
7. Try to securing the A plate from part line to help the hot runner maintenance (it can be done when the mold in the press)
8. Was the connector for power and thermocouple approved by customer?
9. The connector should always be placed on top of mold unless otherwise specified;
10. No water fittings around the power connector;
11. No interference between power connector and hoist ring and other items;
12. The type of thermocouple?(J type);
13. Was a mold flow run? Is it ok?
14. Is the 2D print for hot runner system available?
15. Is a hot runner design tag and maintenance available? Is it secured to the side of mold?
16. Is there no sharp edge in clearance channel for wiring? The corner is bigger enough?
17. Is the oil channel design ok? Is the correct “ O” ring used?
18. The insulation sheet was needed at top and bottom plate for all the hot runner mold;
11.Safety Switch/Data Code/Hydraulic /pneumatic System
1. Was the oil cylinder style, supplier and specification approved by customer?
2. Is the stroke and pressure of cylinder ok?
3. Was the diagram of oil placed on the side of mold?
4. Was the oil cylinder No. correct?
5. Was there any interference between cylinder and other component? Is the safety switch needed?
6. Was the cycle counter approved by customer? Is it on the operator side?