Direct Injection Process:
To produce a DIP safety shoes. it goes through 4 processes:
1. Loading lasted upper to dummy
2. Insert pre-moulded rubber outsole
3. Heat activation
4. PU injection to fill up the cavity between the leather upper and moulded outsole
Shoe Upper Insertion – This process required skill through experience.
The shoe technician need to load the lasted upper to ensure it sit firm and on the right position of the dummy. This is
because the last was placing upside down).
Rubber Sole Insertion – Pre-moulded rubber sole are placed, pressed firm on the aluminium mould.
This need a fast and precious skill as the mould will be closing automatically at a set time.
Heat Activation – Heating process help to strengthen the internal bonding between PU and outsole.
Thus the sole will be stronger and more durable.
PU Injection – The melted PU acts as a strong adhesive agent between the leather upper and the pre-moulded
rubber outsole. The nature of PU are soft hence it also serve as a cushioning for the entire shoe.