Mould Releases and Composite Preforms

[Obsidian]

Hi All ,

Whilst I have an understanding of the use of mould releases and the process requirements when curing thermosetting expoxy composites , I am less sure of the issues surrounding the manufacture of preforms .

The carbon fibre we are using to fabricate RTM preforms is coated with a lacquer that improves drapability however over time constant use of this preform material leaves a residue on the preform tool .

To counter this we are considering placing a liquid mould release on the preform tool allowed to flash off and polished , so that it may be easily cleaned however I am concerned of possible contamination issues as the released preform cannot be easily treated to remove any potential contaminants arising out of the moudl release application . There is a concern that this would give us problems during an infusion cure .

I am aware that we could stove the released tool to reduce the changes of contamination but is this :-

i) a genuine concern
ii) something that has to be considered
iii) something that has to be designed out of the process

?

Thanks

O

 

[Compositepro]

I don't know what you mean by a lacquer that improves drapeability. But any liquid mold release should be dry and solid before a mold is used. Solid coatings can transfer slightly but they will not cause any real problems. If you get liquid release on the preform it will affect bonding between resin ans fiber. That is generally bad. However, for balistic armor poor bonding betwee resin and fiber can improve performance.