APPLYING RAPID TOOLING FOR INJECTION MOLDING & DIE CASTING From a RT users perspective

Transcription

1 APPLYING RAPID TOOLING FOR INJECTION MOLDING & DIE CASTING From a RT users perspective Glenn Anderson Senior Engineer, Research and Development Southco, Inc. RPA/SME Technical Forum on Rapid Tooling 20 Aug 2001

2 Overview 1. Setting Expectations 2. Planning for Failures 3. Project Specification 4. Tooling Requirements 5. RT Selection 6. CAD Preparation 7. Ordering Rapid Tooling 8. Rapid Tool Finishing 9. Process Set-up and Processing

3 Setting Expectations for RT Communications Design changes in part or tooling (are any expected?) Supplier: if delivery date slips Part Quality Dimensional control Surface finish aesthetics Mechanical properties relates to end part molding process parameters Tooling Durability Ease of repair, design changes Processing performance capability Processing Raw Material supplied by customer or supplier Tool Failure (removing stuck parts, part to tool material compatibility) Cycle time

4 Example of Rapid Tooling: Spin Casting: Zinc in Rubber Tooling 3 days functional parts

5 Planning for Failures Completion of paperwork and issuing PO Terms of supplier Are 3D files complete and error free? Queue time & fabrication at RT supplier RT manufacture process Customer priority Delivery of parts to customers deadline Tool failure Shipping time through Customs (off shore purchase) Secondary operations Tool finishing texture, coating, etc. Part processing Raw material availability Damaged tool

6 Project Specification Time Scale & Budget Allowance for quoting activity Use of 3D printed RP parts for quoting activity saves money and time Buy: parts, mold cavities, mold base insert, or complete tool Quality Part design requirements: tolerance, cosmetic, texture, mechanical properties Tooling requirements RT specification Quantity & Expected Life of Tooling Multiple tool planning-quick response / next generation. incomplete impression for shortened response, revise part for next process step Parallel development of next generation tooling can save

7 Tooling Requirements Part Requirement Concept Functional Pre-production, production like(tool Life) Production Tool material characteristics Any concern for future production mold Part material Compatibility with RT materials Shrink rate (locks in choices for alternatives)

8 Rapid Tool Selection Direct RT Processes Direct Metal Processes Precision Optical Manufacturing DMD, Optomec LENS, CNC Machining - traditional or high speed Aluminum, tool steel, Indirect RT Processes SLS Laserform ST100, Direct AIM(SLA), 3D Keltool, investment cast, cast epoxy, Cast steel, spray metal, RTV rubber for spin casting, nickel shell, Hybrid-mixed RT process. e.g. CNC P20 Cavity & SLS Laserform ST100 core with conformal cooling

9 RAPID TOOL TEST - Plastic Injection Molding Nickel Plate Shell Aluminum Filled Epoxy Spray Metal Steel CNC QC7 Aluminum SLS Rapid- Steel 2.0 SLS Copper Duraform

10 RAPID TOOL TEST - Zinc Die Casting CNC P20 Steel SLS Laserform ST100 Investment Cast H-13 Steel SLS Rapid- Steel 2.0 POM DMD H13 Steel

11 Ordering Rapid Tooling Non-technical issues that can affect project delivery Is a cash deposit required with PO to start? Do they accept credit cards for tooling purchase? Is queue time included in the delivery quotation? Definition: Delivery time starts with issue of PO and ends with molded parts or delivery of tooling. Is the part design complete? What 3D CAD file type is preferred by supplier? Native CAD System (e.g. SDRC, Pro-E, etc.), IGES, STEP, STL, Other. What CAD file type will accelerate process? Send 3D RP part, CAD file & 2D drawing with PO or design changes! 2D drawing should have critical dimensions and tolerance requirements outside of RT process Inclusion of supplier and supply chain in design change procedure. (keeps all involved, informed) Who owns the tool? Can it be brought in house after parts are run?

12 3D CAD Preparation Part Parting line, witness lines, draft, ejector pin locations Apply material shrink factors to determine allowances Tool Design (are hand loaded inserts required?) Additional shrink requirements from tool fabrication? Finish stock allowances Tool core/cavity registration features, ejection system, cores and slides, sprue, runner, gate, vents, overflows. Clamp height of tool. Cooling Use of analytical methods to design & optimize performance MoldFlow for plastic injection molds Corner radii allowance for cutting. Allowance for possible future part change.

13 Rapid Tool Fit and Finishing CNC Milling, EDM (sinker or wire), Grinding Tool Material magnetic or non-magnetic Hand work, polishing Texturing and/or Engraving (adds 1 week, minimum, to process) In some transfer processes,, texture can be applied on master pattern and transferred into tool. Plating or hard coating (adds 1 week, minimum, to process) If mistakes are made, can it be repaired?

14 Zn Die Cast Rapid Tool As Produced After testing Note: Step on end wall Note: Epoxy filler on end wall

15 Set-up and Processing Type of tooling Plastic injection molding Zn or Al die casting PIM / MIM Operator/Mold Set-up Technician Are they familiar with RT material and construction? Are there special processing procedures? Hand loaded inserts multiple sets for consistent processing, assembly and disassembly Process monitoring extends life of tool Temperature measurement Pressure measurement

16 Conclusions Learn & understand each RT process Adjust dimensions to meet tolerances of Parts and Tools (finish stock) Quantity of Parts - finite life of tool (need to know up front the total part requirement from the tooling) Mold Processing and durability (actual versus expected) Part Aesthetics as finished or texture, logos and polished surfaces Design parts to support the RT process when possible simplification may be required, either part or tool Future part requirements Possible alternate materials or additional quantities (e.g. changes to resolve test failures) Research RT supplier capability Do they have a Quality Control tracking system in place for parts and tooling? Tool quality and quantity produced (ask to see sample parts) Delivery (issue of PO to delivery of tooling or parts) Willingness to communicate problems or notify changes in schedule Costs Compare costs from several suppliers and RT processes Quantity and quality of RT produced molded or cast parts

17 Conclusions (cont.) Conclusions (cont.) Plan for failures in design, schedule and tooling Consider plan B and what if scenarios for critical steps Do not forget about non-technical aspects of using rapid tooling Requires tool core/cavity design work to be completed before RT fabrication Tool design must occur concurrently with part design Rapid Tooling from Concept to Production tool Most effective as a planned step - not as effective when applied as crisis driven to meet a deadline. Part design and CAD file must be complete and error free. Part redesign or simplification may be required to shorten schedule. Secondary operations (example: flash removal, hand loaded inserts) Rapid tooling parts can/may be different than hard tooled parts and be interchangeable.

18 Recommendations: Select the RT fabrication process that meets/fits your project objectives. Understand the limitations of RT processes. Research supplier capabilities. Quote several suppliers and/or RT processes. Design parts/tools to the manufacturing process (DFM). Consult with mold/die designer early and throughout project (Southco has a Rapid Tooling Specialist on Tool Design staff) Keep them abreast of any part design changes. Part simplification can save time and money. Use standard size mold base pockets and/or insert type mold bases when possible.

19 Questions? Glenn Anderson Senior Engineer, Research and Development Southco Incorporated 210 North Brinton Lake Road Concordville, PA Phone: FAX: