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Activity 001: Heat Press Calibration and Flat Substrate Production Run

Activity ID: U9M4-ACT-001 Duration: 40 minutes Objective: Calibrate the heat press for temperature and pressure, then execute a production run of 3 identical HTV garments with quality control checks.

Overview

Students perform a full heat press calibration (temperature verification and pressure adjustment), then apply the same HTV design to 3 identical garments, implementing quality control procedures including inspection and documentation. This simulates a small production environment.

Materials & Equipment Needed

  • Heat press (clamshell or swing-away)
  • Infrared thermometer
  • Copy paper (for pressure test)
  • Pre-cut and weeded HTV design (3 identical copies from M3 activities or pre-prepared)
  • 3 identical T-shirts (cotton or cotton/poly blend)
  • Teflon sheet
  • Ruler/placement template
  • Heat-resistant gloves
  • Quality control inspection worksheet
  • Timer

Instructions & Procedure

Phase 1: Temperature Calibration (8 minutes)

  1. Power on the heat press. Set temperature to 305°F. Wait for the ready indicator.
  2. Using the IR thermometer, measure the upper platen temperature at 9 points: center, 4 corners, and 4 edge midpoints.
  3. Record all 9 readings on the calibration worksheet.
  4. Calculate the average temperature and the maximum variance (highest - lowest reading).
  5. If average differs from set temperature by more than 5°F, note the offset and adjust the set temperature to compensate.
  6. If variance between readings exceeds 10°F, flag the press for maintenance.

Phase 2: Pressure Calibration (5 minutes)

  1. Place a sheet of copy paper between the closed platens.
  2. Close the press.
  3. Attempt to pull the paper out. Assess resistance: light, medium, firm, or stuck.
  4. Adjust pressure to achieve "medium" resistance (the paper pulls out with moderate effort).
  5. Repeat the paper test at center and all four quadrants to verify even pressure.
  6. Document the pressure setting on the worksheet.

Phase 3: Production Run (20 minutes)

For each of the 3 garments: 1. Pre-press the garment (5 seconds at 305°F). 2. Position the HTV design using the placement template. Ensure consistent placement on all 3 garments. 3. Cover with Teflon sheet. 4. Press: 305°F, 15 seconds, medium pressure. 5. Peel carrier (hot or cold per HTV type). 6. Post-press: 3 seconds through Teflon sheet. 7. Set aside to cool. 8. Record the time/temperature/pressure used for each garment.

Phase 4: Quality Control Inspection (7 minutes)

For each of the 3 garments, inspect and record: 1. Adhesion test: Fingernail edge test at all 4 edges of the design. 2. Visual inspection: Bubbles? Wrinkles? Scorching? Missing elements? 3. Placement measurement: Measure distance from collar to top of design. Measure centering. 4. Consistency check: Compare all 3 garments side by side. Are placement, color, and adhesion consistent? 5. Rate each garment: Pass / Fail / Rework Needed. 6. For any garment rated "Rework," describe the corrective action.

Discussion Points

  • How much temperature variance did you find across the platen?
  • Were all 3 garments consistent? What caused any variations?
  • How does the calibration step at the beginning affect production quality?
  • What would a production run of 50 garments require differently from 3?

Expected Outcomes

  • Heat press calibrated within ±5°F of target with even pressure
  • 3 garments with consistent design placement, adhesion, and quality
  • Completed calibration and QC worksheets with accurate data
  • Understanding of production quality control workflow

Assessment Rubric

Criteria Excellent (4) Proficient (3) Developing (2) Beginning (1)
Temperature Calibration All 9 points recorded, variance <5°F 9 points recorded, variance <10°F Incomplete readings Cannot perform calibration
Pressure Calibration Even pressure verified at 5 points Even at 3+ points Uneven, noted but not corrected Cannot perform pressure test
Production Consistency All 3 garments pass QC, consistent placement 2/3 pass, minor variation 1/3 passes None pass QC
QC Documentation Complete, accurate inspection records Minor omissions Significant gaps No documentation

Safety Considerations

  • IR thermometers measure surface temperature only—do not touch the platen surface
  • Allow the press to reach stable temperature before production (5+ minutes after ready light)
  • Use heat-resistant gloves when handling garments during the production run
  • Keep the Teflon sheet in place during all presses to protect both garment and platen
  • Maintain a clear, organized workspace to prevent garment mix-ups

Last Updated: 2026-03-19