nd compressing under heat by sandwiching between heated plates to cause penetration and close flap openingUS6723308 *Nov 2, 2001Apr 20, 2004Kenra, LlcPre-straightening the hair, first removing a residue from the previous straightening treatment, treating with an aqueous solution including an acids and an amphoteric surfactantUS6805136Nov 2, 2001Oct 19, 2004Kenra, LlcApplying hydroxide of calcium,