摘要 |
The invention relates to a hydrophilic yarn or thread (1) which is soluble in hot water and which is coated or impregnated with hydrophobic materials or a combination of hydrophobic and hydrophilic materials. The coating medium (2) includes, but is not limited to, binders such as polyvinyl alcohol (PVOH), guar gum, gelatine, carboxy-methyl cellulose (CMC), acrylic polymers, polyvinyl acetate (PVOHC), security pigments, dyes, machine readable taggants such as phosphors, PCR readable DNA tags, rare earth, magnetic particles, and X-ray readable particles, and the security yarn or thread (5a) so formed shall carry the security readable features in one or more varieties, and such security yam or thread is subsequently inserted within a bed of paper pulp during the paper making process to form a high security paper, such as bank note paper, fiduciary paper, or passport paper. The security features carried by the yarn or thread can be extracted from, or detected in, the said yarn or thread in a suitably equipped forensic laboratory to, amongst other benefits, authenticate the manufacturing site at which such paper was produced. |