What are the safety devices on injection molding machines
Injection Unit: In addition to basic metal plate guard, there is injection safety cover at the nozzle area for preventing splash of material. Injection unit will not be able to act without the cover in position.
Clamping Unit: In addition to basic metal plate cover and front and rear safety door, there are mechanical, hydraulic and electrical safety devices. When the machine is in operation, all these safety device would be activated, if one of the safety door is opened, and the clamping unit will stop moving.
Mechanical device: Generally, there is a safety lever on the movable mold platen. At emergency ( one of the safety doors being opened ) with the mechanical blocking or grabbing, the clamping mechanism will be stopped forcefully.
Hydraulic device: To offer further protection, when one of the front and rear safety door is opened, the relief valve will exhaust pressure in the system, and the clamping element will become inactive.
Electrical device: To prevent the failure of relief valve, when one of the front and rear door is open, the 2 limit switches on the safety door will have no signal of door closing and open signal is available, then the clamping element will be inactive.
Emergency Stop Switch: A red "Emergency stop" press button is installed to each of the front and rear operation cabinet. When one of them is pressed, electrical motor and pump will cease operation immediately ( but the power is still on), the machine will not be able to operate. Before operation of the machine, validity of these two buttons must be tested. If any one is invalid, complete check must be done to be safe.