Good overview of injection molding

I do injection molding it's a small part. Before injection molding I made a rubber mold of the part then poured a plastic resine into the mold wait an hour and de-mold. Let the part set-up for an hour. Because of the time decided to go the injection molding route. First inquired about having a person already injection molding making the part for me but due to the initial cost of $12000.00 decided not a good way to go. Researched benchtop models bought a unit initial cost $1800.00 had a mold made from steel cost $1000.00. The reason steel was longer mold life. The model I purchased was a tube with plunger manual lever. Wanted to inject abs but couldn't produce the force required to fill mold cavity. Converted unit to to pneumatic. Installed a 5 inch bore cylinder for the plunger and a 2.5 inch cylinder for clamp. I inject polyprolpylene not abs because with abs I get flash which is moisture that flashes under pressure and causes a white defect of the plastic. Abs absorbs moisture and has to be dried before injecting into the mold but I don't have a drier. Injection molding is similar to 3D printing it's a learning process that doesn't have a manual to tell you what to do when you have a problem.