The Role of Heating Time in the Thermoforming Process

The Role of Heating Time in the Thermoforming Process

Heating time is one of the main parameters of the thermoforming process. The time required to heat the plastic sheet to its forming temperature is called the heating time, which is generally 50% to 80% of the whole forming cycle. Thus, in the forming process, optimizing the heating time is critically important.

In the thermoforming process, the sheet reaches a thermoplastic, highly elastic state within the temperature range required for stretch forming, so the sheet must be heated to the specified temperature before forming. Therefore, the accuracy of the heating temperature and the uniformity of the temperature distribution of the sheet will directly affect the difficulty of the moulding operation and the quality of the products.

The required heating time for the sheet is primarily determined by the polymer type and sheet thickness, usually heating and cooling time with the thickness of the product and the material specific heat capacity increases and extends, with the sheet thermal conductivity and thermal diffusion coefficient of the increase and shorten, but these time variations do not follow a simple linear relationship.

The optimal heating time is typically determined through experiments or empirical data references. Of course, the heating time is also related to the type of heater, the surface temperature, the distance between the heater and the plate (sheet), the ambient temperature and many other factors, so it is more complicated.

Advanced heating systems, such as the GtmSmart  multi-station thermoforming machine with adjustable ceramic heating tiles, provide precise control and flexibility for different production needs.

Heating System of Thermoforming Machine

Heating mode: upper and lower heating, separate control (thin sheet, can be single heating, thick sheet, can be upper and lower together) 
Heating tile: 6*18 ceramic tile, they can be adjusted individually.

With advanced heating systems, high quality thermoforming products can be produced. Of course, we will continue to research and develop, and in the future, the heating technology and process automation will also be more advanced, so as to improve the accuracy and reliability of thermoforming machines.