The CC Combi is a custom-design surface treatment tailor-made to the plastic type and the application suitable for a wide variety of tool parts in injection moulding tools. The solution is a duplex treatment consisting of a dry lubrication coating (CC DLC) and a coating, to reduce sticking of mould material and ease the demolding, selected to match the respective application and plastic material used (i.e. ABS, PE, PA, POM, PPS, TPU, TPE etc.). A desired side-effect is protection against wear, for example from glass fibres or pigments, and resistance to corrosion, i.e. from fire retardants.
One of our customers, a manufacturer of screw caps processed in PP to containers for beverages in a large amount and in different colours, have benefited from CC Combi. As the subject is designed to be in contact with food the production must comply with strict requirements, e.g. no fat deposits or oil remains on the subjects produced. The tool is a multi-cavity mould where the thread is moulded using a servo motor drive.
During run-in of the tool several problems occurred:
- lubrication with oils was necessary to avoid scratches during demolding causing risk of leaving remains on the thread
- spite the high surface quality of the tool, linting (particle formation of the plastic used to produce the subject) was evident after a very short time producing
- the subject was deformed due to the plastic sticking to the tool steel surface during demolding
- frequent maintenance was necessary, including disassembly of the thread core and repolishing of the thread – a time-consuming process
- frequent production stops due to quality issues
A total of 32 thread cores was coated. The cavities with a coating for better slip, which physically isolates the tool steel from the plastic. This remedied linting and eased the demolding force with 20 %. The sliding surfaces were coated with a dry lubricating coating which is hard and has a very low friction coefficient against steel. The coating acts as an isolator between the metallic surfaces and replaces the use of grease and lubricates. Also, it protects against wear on both surfaces. The subject can now be produced in compliance med requirements and in the desired quality.
See customer case in download.