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Module 4: Post-Processing & Curing

Duration: 3 hours | Microcredential: MCCPDL-U02M4-v1.0

Module Overview

This capstone module covers the complete post-processing workflow: removing prints from platform, washing in IPA solvent, UV curing, support removal, finishing, and waste disposal. Students learn chemical handling for IPA wash, UV curing parameters (intensity, duration, temperature), safe support removal techniques that preserve fine details, and environmental compliance for chemical waste. The module emphasizes that SLA post-processing is as critical as printing to achieve quality final parts.

Learning Objectives

  1. Safely remove cured print from build platform
  2. Execute IPA wash procedure: agitation time, temperature, disposal
  3. Configure UV curing parameters: wavelength, intensity, duration, temperature
  4. Remove supports cleanly: cutting angles, sanding, avoiding damage to features
  5. Finish surfaces: sand, polish, paint, assemble
  6. Measure tolerances and verify dimensional accuracy
  7. Manage chemical waste per EPA regulations

Key Concepts

  • Uncured Resin: Sticky, hazardous; requires careful IPA wash for removal
  • IPA Wash: Dissolves uncured resin; multiple short washes better than one long wash
  • UV Curing: Completes crosslinking; over-curing yellows or warps parts
  • Support Removal: Angle cuts minimize stress on thin features; iterative removal vs. aggressive removal trade-off
  • Surface Finishing: 200-600 grit sanding for smooth finish; 1000+ for high polish
  • Post-Curing: Some resins (like certain Tough formulations) benefit from post-cure heat (65-80°C, 30+ min) for strength development

Time Allocation (180 min total)

Segment Duration Activity
Safety Review & PPE Check 10 min Verify PPE, chemical handling, ventilation operational
Slide 1: IPA Wash Procedure 20 min Presentation: wash stages, agitation, drying
Activity 1: IPA Wash Demonstration 40 min Supervised: students wash completed print, verify uncured resin removal
Break 15 min —
Slide 2: UV Curing Parameters & Equipment 20 min Presentation: UV wavelength, intensity, time calculation, temperature effects
Activity 2: UV Curing Execution 30 min Students cure their print: monitor time, note color/hardness changes
Slide 3: Support Removal & Finishing 20 min Presentation: cutting angles, sanding, polish, paint, assembly
Activity 3: Support Removal & Surface Finishing 40 min Students remove supports carefully, sand to desired finish
Slide 4: Quality Inspection & Waste Disposal 15 min Presentation: tolerance measurement, defect assessment, waste disposal procedure
Activity 4: Final Inspection & Documentation 15 min Students measure part, complete documentation, dispose of waste properly

Assessment Strategy

  • Formative: 10-question quiz on post-processing procedures and safety
  • Practical: Successfully wash, cure, and finish a print with acceptable surface quality
  • Competency: Produce final part meeting dimensional and surface finish requirements

Standards Covered

  • OSHA 1910.1450: Chemical handling and waste management
  • EPA: Hazardous waste classification and disposal
  • ISO 52891:2022: Environmental sustainability in additive manufacturing

Prerequisites

  • Completion of Modules 1, 2, 3 (SLA Technology, Chemical Safety, Print Setup)
  • Completed print ready for post-processing
  • Safety certification from Module 2 (ongoing requirement)

Resources Needed

  • IPA wash station (agitation capability)
  • UV curing chamber (controlled time, temperature)
  • Support removal tools: fine tweezers, mini files, cutting tools, sandpaper (200-1000 grit)
  • Measuring tools: calipers, tolerance gauge, straightedge
  • Finishing supplies: paint, brushes, epoxy (if applicable)
  • Waste containers: labeled for spent IPA, uncured resin scraps, contaminated materials
  • Documentation: print log, finish quality rubric, tolerance measurement form

Success Criteria

  • Score ≥70% on knowledge quiz
  • Successfully wash print without residual uncured resin (visual inspection)
  • Cure print with uniform hardness (no tackiness; proper mechanical properties)
  • Remove supports cleanly without damaging part details
  • Achieve surface finish acceptable for application (rough, sanded smooth, or polished)
  • Measure tolerances within acceptable range for design
  • Properly dispose of chemical waste and document disposal

Capstone Project (Unit Completion)

Students design and execute complete SLA print-to-finish cycle: 1. Design or source STL file (functional part: bracket, fixture, prototype component) 2. Prepare model (M3): orientation, support generation, exposure settings 3. Execute print (M3): startup, monitoring, completion 4. Post-process (M4): wash, cure, finish, measure 5. Document: photos at each stage, dimensional verification, tolerance analysis 6. Reflection: Design improvements? Alternative approaches? Manufacturing constraints learned?

Next Steps

  • Unit 02 Completion: SLA microcredential awarded
  • Transition to Unit 03 (Laser) or Unit 04 (CNC)
  • Advanced SLA: Specialty resins (transparent, dental, castable), two-stage curing, precision applications

Last Updated: 2026-03-18 Emphasize: Post-processing quality directly affects final part performance and appearance. Rushing this stage wastes the time/cost invested in printing.