Maintenance is the combination of all technical, administrative and managerial actions during the life cycle of an item intended to retain it in, or restore it to, a state in which it can perform the required function
After molding is carried out, it is necessary to carry out maintenance of the plastic injection molds such as disassembling and cleaning, etc. (maintenance and inspection work).
The “soot” constituents generated from the molding material, and the condensed gas deposits, etc. accumulate on the surface of the cavity or core and on the parting surface.
Although these constituents are still in the liquid state when the mold is still at a high temperature, but when the mold cools down they solidify, moisture content in air gets adhered because of these, eventually causing the generation of rust and corrosion of the mold.
When this state is reached, the surface quality of the molded item decreases, there will be fluctuations in the dimensional accuracy, insufficient air escape, which causes the generation of short shots.
The frequency of maintenance varies widely depending on the status of quality management of the molded item, and on the size of the mold, etc.
A common method of maintenance is to disassemble the mold, cleaning each of the part by ultrasonic cleaning, or by rinsing in an organic solvent, and to remove the rusted part by polishing and then electroplating.
In the case of parts having a lot of rust, the parts are replaced, or the inserting part is corrected.
Copar cares about Clients which are their partners, support them and submit the complete service. In addition, we submit a mold book with check list for each dispatched mold.
Moreover, Copar has a reference for each part in the mold, if there is a problem in a part, no need for the client to send the mold to our factory for maintenance, our client may send us the name of the part and directly we send them the spare part needed, this will let our clients not to waste time.
Even the work bench needs to be modified so that the work becomes easy. Modifications are to be done about the work bench height to improve ease of carrying out the work, walking space, crane position, air gun piping, etc.
In order to increase the efficiency of maintenance, it is necessary to give considerations from the point of designing the mold.
Holes are provided so as to facilitate disassembly of the mold, screws for hook bolts are provided, and supplementary screw holes are provided for assembling.
The cores should have the frame block construction so that they do not come apart, and it is also effective to use a construction of fixing using keys.
Very often the placement numbers of core pins are engraved, and tag cuts are made in order to fix the directionality.
And here are steps for Mold Maintenance we should check it:
Check if there is any water leakage
Coat the cavity and core surfaces with silicon spray
Grease the gears and bearing.
Check delta T between cavity and core side should not exceed 5°C.
Check the temperature on cavity and core side should not exceed 40°C.
Check the mold installation if screw are tight and check mold leveling.
Check the flow and pressure of inlet and outlet water.
Coat the mold steel surfaces with corrosion preventive.
Disassemble the mold and clean its water channels.
Before Storing the Mold:
Dry the cooling channels by composed air.
Manually, lubricate all mold parts and surfaces.
Manually, grease the guides.
In order to maintain a long lifetime for the mold, good maintenance must be done to the mold, since the mold is the heart of the machine, this will lead for high quality of the produced plastic with perfect finishing.