Slide 002: Temperature Calibration, Pressure Adjustment, and Transfer Types¶
Slide Visual¶
Slide Overview¶
This slide covers the critical setup and calibration procedures for heat presses, and introduces the major transfer types beyond HTV including sublimation and screen print transfers.
Instruction Notes¶
Temperature Calibration¶
The digital temperature display is a target, not a guarantee. Actual platen temperature must be verified independently.
Verification methods: 1. Infrared thermometer: Point the IR gun at multiple locations on the upper platen. Take readings at center, each corner, and each edge (9 points total). All readings should be within ±5°F of the set temperature. Variance greater than 10°F indicates a failing heating element or control issue.
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Thermal strips: Adhesive temperature indicator strips placed on the platen surface. They change color at specific temperature thresholds, confirming the platen reaches the set temperature.
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Thermocouple probe: The most accurate method. A probe placed on the platen surface connected to a digital thermometer. Used for professional calibration.
Calibration frequency: Monthly for production environments, at start of each session for educational use, and whenever results seem inconsistent.
Pressure Adjustment¶
Pressure is adjusted via a screw mechanism (manual presses) or air pressure regulator (pneumatic presses). There is no universal pressure scale—it varies by machine.
The paper test: Place a sheet of standard copy paper between the platens. Close the press. Attempt to pull the paper out. Results: - Slides out easily: Pressure too light - Moderate resistance: Light pressure (good for puff HTV, delicate fabrics) - Firm resistance, can still pull with effort: Medium pressure (standard HTV, most transfers) - Cannot pull out without tearing: Heavy pressure (too much for most applications)
Pressure verification: Test at center and all four quadrants. Even resistance = even pressure. Uneven results indicate a worn pad or misaligned platens.
Transfer Types Beyond HTV¶
Sublimation Transfers - Printed on specially coated paper using sublimation ink - Pressed at 380-400°F for 45-60 seconds, medium-firm pressure - Works ONLY on polyester fabrics (65%+ poly) and polymer-coated substrates - Produces photographic-quality, full-color images - Design becomes part of the fabric—no hand feel, does not peel or crack
Screen Print Transfers (Plastisol) - Pre-printed on release paper by a screen printing shop - Pressed at 325-375°F for 7-15 seconds, firm pressure - Works on cotton, polyester, and blends - Softer hand feel than HTV - Available in hot-peel and cold-peel varieties - Cost-effective for large quantity orders with the same design
DTF (Direct to Film) Transfers - Printed on PET film with white ink base layer and adhesive powder - Pressed at 300-325°F for 10-15 seconds, medium pressure - Works on virtually any fabric type (cotton, polyester, blends, nylon) - Full-color capability with white ink for dark garments - Growing rapidly in popularity due to versatility
| Transfer Type | Temp | Time | Fabrics | Full Color? | Hand Feel |
|---|---|---|---|---|---|
| HTV | 305°F | 10-15s | Most | No (single color) | Raised, smooth |
| Sublimation | 385°F | 45-60s | Polyester only | Yes | None (dye-infused) |
| Screen Print | 325-375°F | 7-15s | Most | Yes | Soft, thin |
| DTF | 300-325°F | 10-15s | All | Yes | Thin, flexible film |
Key Talking Points¶
- Temperature calibration is the single most important quality control step
- Pressure affects adhesion as much as temperature—both must be correct
- Sublimation is limited to polyester but produces the best hand feel and durability
- DTF is the most versatile transfer method available today
Learning Objectives (Concept Check)¶
- Can students calibrate a heat press using an IR thermometer?
- Can students perform the paper test for pressure verification?
- Can students select the correct transfer type for a given application?
Last Updated: 2026-03-19