3.Machining and processing HPL
The forming area of the postforming HPL has to be heated to the forming temperature recommended by the HPL manufacturer. The selected process and with it the relationship between applied heat quantity, energy type and application time mostly determines the behaviour of the HPL material during forming. The heat can be applied with infrared radiators (medium, long or short wave) or heating bars. Exact temperature control of the HPL in the forming area is therefore indispensable (e.g. temperature sensor, optical measuring systems). If the defined temperature is exceeded, delamination (bubbles) can occur in the HPL. If the temperature is too low, cracks can form.
Reaching and maintaining the temperatures required for forming are essentially influenced by the following factors:
The forming speed essentially depends on the applied energy quantity, the thickness and sanding direction of the HPL, the radius of the curve to be formed and on whether it is concave or convex. Fastest possible heating of the HPL and a rapid forming process are crucial. It is important that the required contact pressure is applied evenly during forming.
Due to the complex parameters, we recommend that users discuss the process beforehand together with the HPL, adhesive and machine manufacturers. Forming trials and quality tests are required at regular intervals.
