Frystorkning Kontrollerad torkning av kulturhistorisk dräkt?
Cultural objects may become wet by deliberate water cleaning, water disaster or watersoaked for other reasons. Air drying textile objects and even other organic materials from awater wet state, involves many problems depending on the strong capillarity action of water.Damages and changes such as bleeding of dyes, stains or lines of impurities from watermovement, shrinking or stiffness can occur. Freeze-drying as an alternative drying methodhas often been used for wet archaeological and marine objects, but more seldom for historicalmaterials.This bachelor thesis addresses the issue of whether freeze-drying can be an alternative controlleddrying method for historic costumes. Costumes and related objects are often compositeobjects, consisting of multiple materials, as well as being three dimensional, all of whichwill complicate drying. The purpose of this study was to investigate whether it is possible tohandle costume objects after wet cleaning for drying by freeze-drying, and if damages due tosurface tension of water, can be avoided in this way. A literature survey was carried out intothe characteristics of water, the processes of wetting and drying, the properties of textile andskin, alternative drying methods and the theory of freeze-drying.Another aim of this thesis was to develop a practical procedure based upon experience.Seven case studies are reported. All objects are Sámi costumes: four ?gákti?/clothing andthree ?gahpir?/caps made of textile, with some skin details. The freeze-drying process wascarried out without vacuum in an ordinary freezing room. Different procedures and handlingof the objects were tested from wet state through freezing, freeze-drying, and to the final airdrying. Changes in dimension, colour and staining from water movement was evaluated afterwards.Observations were carried out during the whole drying process on the drying behavior.Appropriate drying equipment and how to decide the drying rate are discussed.The results suggest that freeze-drying can be an alternative drying method and a way tocontrol the drying of historic costumes after wet cleaning. Damages due to air drying shouldin most cases be avoided by freeze-drying. A method to handle objects before freezing wasinvestigated, in which the goal was to keep the object as wet as possible prior to placing inthe freezer. This reduced the risk of damage from water movement and also the pressure oftime. Some guidelines are given for practical use.