Injection molding method

An injection molding method, comprising:

• providing an extruding system configured to produce a mixture of a polymeric material and a blowing agent, a first discharging channel, a second discharging channel, and a molding device including a hollow space, a first feeding port and a second feeding port,
• wherein the first discharging channel is communicable with the extruding system and includes a first outlet disposed distal from the extruding system, the second discharging channel is communicable with the extruding system and includes a second outlet disposed distal from the extruding system, and the first feeding port and the second feeding port are communicable with the hollow space and respectively engageable with the first outlet and the second outlet;
• securing at least one of the first discharging channel and the second discharging channel to the molding device by engaging a first element of a supporting device relative to a second element of the supporting device, wherein the first element protrudes from the extruding system, and the second element is disposed on the molding device;
• engaging the first outlet with the first feeding port;
• engaging the second outlet with the second feeding port;
• injecting a first amount of the mixture into the hollow space through the first outlet and the first feeding port;
• and
• injecting a second amount of the mixture into the hollow space through the second outlet and the second feeding port.