KYDEX V KYDEX V sheet has excellent forming properties, which results in uniform wall thicknesses and crisp detail. KYDEX V sheet forms to deep draws with low forces when heated to the upper end of the forming temperature range. Unlike many other thermoforming sheets, KYDEX V sheet has unusually high resistance to hot tearing. Forming Guidelines - Oven temperatures should be set differently than the settings used for ABS or FR-ABS. - Typical heater settings (percentage timers) are 30% - 50% top heaters and 50% - 70% bottom heaters. - The most frequent problem is trying to heat the sheet too quickly, particularly on the primary surface. - Cycle times will vary depending on the oven conditions and grade of KYDEX V sheet being formed. - When forming KYDEX V sheet, it is better to rely on the sheet appearance during heating than on fixed cycle times. - Forming temperatures - Guidelines: (Sheet should not exceed 204°C (400°F). 165 - 177°C (330 - 350°F) for < 1.50mm (0.060"). 182 - 196°C (360 - 385°F) for 1.50mm to 3.20mm (0.060" to 0.125"). 196 - 204°C (385 - 400°F) for > 3.20mm (0.125") - Ideally the core sheet temperature should be within 10°F of the surface temperature. Sheet Appearance During Heating As KYDEX V sheet is heated, the inherent stresses in the sheet will relax. Stage I: The heating is marked by wide undulations and softening. Stage II: The material will start to form small ripples (known as oil canning). . Stage III: The material will start to smooth out and sag (KYDEX V sheet will generally sag less than other thermoplastics due to its high melt strength. . Stage IV: The ripples will have smoothed out indicating that most stresses have been removed. 10 to 30 seconds afterwards the sheet is ready to form.