The History of Lamination
When it comes to lamination necessity, lamination is exactly that. It is necessary. That is why it was invented in the first place, because the human race had a need for it, and that need has been around for generations. Read on to experience the growth of the lamination process through the ages!
Lamination is a method of strengthening fragile papers. Less time-consuming than traditional methods, lamination was widely used by archives from the 1930’s through the 1970’s. The lamination process involved de-acidifying a document, layering it between tissue and thin sheets of plastic, and fusing them together in a heated press.
In archival contexts, lamination refers to the process of fusing a sheet of paper between two thin sheets of plastic — usually cellulose acetate. The archival community embraced lamination in the early 1930s as a means of strengthening fragile papers. It provided stability for weak or damaged documents in less time than traditional methods, making it cost-effective for large collections. Collections were often laminated before microfilming, to facilitate rapid handling. Lamination was also seen as a means of preventing damage from environmental contaminants and grime from handling.
The National Archives, the Library of Congress, and other organizations with large collections– and budgets large enough to afford the equipment — began lamination projects in earnest by the late 1930s and 1940s. Institutions or organizations lacking the resources to acquire their own equipment often contracted the work to these other agencies. Lamination was recommended initially for records of little intrinsic historical importance, but it was soon applied indiscriminately. Publications of the era described lamination as a panacea, and even such priceless documents as the Emancipation Proclamation were laminated.
As the lamination process was developed, numerous inventors and scientists — most notably William Barrow — experimented with ways to refine the technique. The National Bureau of Standards eventually made an attempt to standardize lamination, recommending a process with several stages. First, the document was to be deacidified, neutralizing the potentially damaging acids inherent in some paper. Next, the document was layered between thin sheets of a plastic — usually cellulose acetate — and tissue. The use of a plasticizer in the cellulose acetate increased the flexibility of the otherwise brittle plastic, as well as decreasing the temperature required to soften it. The addition of a thin layer of Japanese tissue on top of the cellulose acetate film greatly improved the tensile strength, internal tear resistance, and folding endurance of laminated documents. It also reduced the shiny appearance of the plastic laminate. Finally, the five-layer “sandwich” of materials was placed into a heated laminating press. The heat melted the plastic layer, while the high pressure forced the cellulose acetate into the interstices of the paper itself, sealing the document within a semi-flexible plastic coating.
Despite the National Bureau of Standards’ attempt to standardize this lamination process, there was considerable variation in technique and in materials. Each laboratory generally retained its own protocols, and the process often boiled down to an individual operator’s or technician’s choice of what functioned well