Layer adhesion refers to the evaluation of the bond strength between layers in a 3D-printed part. Generally, 3D printed products are built layer by layer where the adhesion between layers may be vary depending on many factors also according to materials used. Furthermore, all the 3D printed parts experience layer separation over time. This issue goes back mainly to the effect of temperature during 3D printing operations. In this research a new technique has been developed, that focuses on studying and controlling the temperature of the environment around the 3D printer. This approach aims to enhance the adhesion or welding process between printed layers. Where at the proper temperature the layer becomes more elastic which facilitates the fusion process of the new layer with existing ones, thereby increasing the mechanical properties of the 3D printed parts. There are many techniques applied to control the temperature where in this study the control system that has been implemented, consists of a digital thermostat equipped with sensors. The system monitors and adjusts the temperature by using an electrical wire heater placed inside the encloser. Many materials are used as base material in 3D printers like PLA, ABS, PETG, etc., and each of these materials has a different optimum temperature, this study focused on PLA materials as the test material, even though they are widely used in 3d printer field, where having a good printing flexibility, on the other hands this material has the biggest influences by the weather conditions, which can lead to failure happened between layers after a short while of time. The experiments were done by selecting three environment temperatures (40,45 and 50 ℃), the number of walls (4,6, and 8walls), and finally printing speed (70,80and 90 mm/sec) to test the adhesion between layers. The results exhibited that the effect of encloser temperature on the 3d printer process was 62.07% over all the other printer parameters, Notably, the increase in the strength of adhesion for the printed parts reached 32.37% at an encloser temperature of 40 ℃. Keywords: 3D-printer, PLA filament, layer adhesion strength, environment temperature.