and molding the plastic material into the plastic element application_number US 201113077916 A description embodiments of the present disclosure will now be described in detail and with reference to the drawing referring to fig1 an exemplary embodiment of a method for injection molding a plastic element is provided the method includes the following steps in step 200 a mold core is provided wherein the mold core defines a mold cavity referring to fig2 in one embodiment a mold core 120 is provided the mold core 120 is used for molding an optical fiber connector using polyetherimide pei resin the mold core 120 defines a mold cavity 110 the mold cavity 110 has an inner surface 111 in step 202 a lubrication layer is positioned on an inner surface of the mold cavity in one embodiment the lubrication layer is comprised of titanium nitride tin and is formed on the inner surface 111 using an atomic layer deposition process in detail the mold core 120 is positioned in a coating chamber 130 the coating chamber 130 includes a gas inlet 131 a gas outlet 132 and an exhaust opening 133 the coating chamber 130 is exhausted to vacuum phase and then heated to a predetermined temperature a first reactive gas is introduced into the coating chamber 130 in the present embodiment an organically metallic gas containing ti such as ticl.