Apple Granted Carbon Fibre Moulding Process Patent
Apple have been granted a patent for a carbon fibre moulding process that could eventually be used to produce casings for laptops, desktop, and possibly other Apple products made using the light weight product.
The Apple patent (No. 8,257,075) describes the processes needed to produce parts of a consistent quality from carbon fibre and other resin based composite materials, as we have seen in both the aerospace and automotive industries the key to making carbon fibre work in mass production environments is automating the process.
As Apple notes in the patent, resins tend to stick to mould surfaces and the removal of a finished part from a mould can be a tricky process that often involves manual intervention. Despite the application of a temporary release coating to inner mould surfaces prior to placing in the composite materials, the removal of a finished part from a composite mould still can involve prying and peeling the part away from the inner mould surfaces. Surface defects and blemishes on composite moulded parts often occur as a part of the moulding and mould removal process, which results in many parts having unique defects or appearances. Further, temperature discrepancies from moulded part to moulded part using traditional composite moulding processes can also result in blemishes or defects that are different for each part. Due to these particular examples and other concerns that relate to composite moulding, many composite moulding processes are highly manual labor intensive by nature, and often result in the formation of parts that are not fully consistent from part to part.
Apple proposes to streamline this manufacturing process by using a two-part moulding system, the mould will have one or more internal fluid lines to assist cooling and will use a permeant release coating made from nickel-teflon, titantium-nitride, an amorphous carbon/diamond like material, chrome or chrome alloy or NEDOX, the permanent release coating will have a thickness of about 1 to 5 microns and can be situated on one mold insert or component or multiple mold components.
Ejector pins help remove the finished part from the mould. An ejector pin shaft cover transfers force to eject a finished part and also prevents substantial passage of resin into the ejector pin shaft. A fluid actuated ejection system provides fluid based mechanical forces to eject the finished part.
Speculation around Apple using composite materials was fuelled when Apple hired Kevin Kenny developer of the first all carbon fibre bicycle frame, indeed Kevin’s name is on the patent application.