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Module 1: SLA Technology & Resin Chemistry

Duration: 3 hours | Microcredential: MCCPDL-U02M1-v1.0

Module Overview

This module introduces the photopolymerization process, resin chemistry, and SLA printer hardware. Students learn how UV light initiates polymer crosslinking, how different resin types (Standard, Tough, Flexible, Transparent) achieve different properties, and how printer optics and exposure settings control curing depth and lateral resolution. The module emphasizes understanding WHY different resins require different exposure settings and how to optimize for quality.

Learning Objectives

  1. Explain UV photopolymerization mechanism: photoinitiation, crosslinking, degree of cure
  2. Compare resin types (Standard, Tough, Flexible, Transparent) and their applications
  3. Understand printer hardware: light source (LED or laser), optics, vat design, build platform
  4. Predict cure depth and lateral resolution based on resin properties and exposure settings
  5. Interpret technical specifications: viscosity, Shore hardness, tensile strength, elongation
  6. Recognize how moisture, temperature, and UV exposure affect resin shelf life

Key Concepts

  • Photopolymerization: UV light hits photoinitiator → free radicals → polymer chains crosslink
  • Resin Types: Standard (baseline properties), Tough (impact resistant), Flexible (elastomeric), Transparent (optical)
  • Cure Depth (Cd): How deep UV penetrates into resin; controlled by light intensity, wavelength, resin absorption
  • Lateral Resolution: XY pixel size determined by light spot size; typically 25-50 μm
  • Exposure Time: Layer thickness (Z) divided by cure rate; must be optimized per resin
  • Degree of Cure: Percentage of photoinitators that react; incomplete cure = weak, sticky parts

Time Allocation

Segment Duration Activity
Introduction 10 min Overview: photopolymerization vs. FDM extrusion
Slide 1: UV Physics & Photoinitiation 20 min Presentation: light-matter interaction, wavelength, initiation
Slide 2: Resin Chemistry & Types 25 min Presentation: polymer structure, resin comparison table
Activity 1: Resin Property Analysis 30 min Students review datasheets, compare properties, select resin for scenario
Break 10 min —
Slide 3: Printer Hardware & Optics 20 min Presentation: LED/laser light source, optics, vat design
Slide 4: Exposure Settings & Cure Depth 20 min Presentation: layer thickness, exposure time, resolution
Activity 2: Exposure Tuning Simulation 25 min Students calculate exposure times for custom resin + layer height
Slide 5: Resin Storage & Shelf Life 15 min Presentation: temperature, light exposure, moisture control
Q&A & Assessment Prep 15 min Review concepts, preview M2 (chemical safety)

Assessment Strategy

  • Formative: 12-question quiz on photopolymerization and resin properties
  • Practical: Interpret resin datasheet and recommend exposure settings for specific application
  • Competency: Calculate cure depth and predict lateral resolution given resin properties

Standards Covered

  • ANSI/ISO 52901:2020: Additive Manufacturing General Principles
  • ISO 52911-1:2019: Design and Modeling—Geometry and Tolerances

Prerequisites

  • No prior SLA experience required
  • Basic understanding of light/UV (high school physics level)
  • Familiarity with material properties helpful (from Unit 01 M1 or equivalent)

Resources Needed

  • Sample resin types (Standard, Tough, Flexible, Transparent—small quantities for demonstration)
  • Technical datasheets for 3-4 resin products
  • UV light demonstration (UV flashlight, objects that fluoresce)
  • Printer manual (hardware specifications, optics design)
  • Exposure setting reference chart (pre-calculated for common layer heights)

Success Criteria

  • Score ≥70% on knowledge quiz
  • Correctly identify resin type given functional requirements
  • Calculate reasonable exposure time for given resin + layer height
  • Explain how cure depth affects print resolution and part properties

Next Steps

  • Module 2: Chemical Safety & PPE (CRITICAL—before hands-on resin handling)
  • Module 3: Print Setup & Execution (apply exposure settings to real prints)

Last Updated: 2026-03-18