Conditions for the safe storage of early glass

古代玻璃通过与土壤或大气中的水相互作用而腐蚀，失去碱并在表面留下富含水合二氧化硅的风化层。腐蚀速率取决于玻璃的组成和周围环境条件。储存时，玻璃可能会继续腐蚀，除非相对湿度较低。优选的RH值通常被引用为约40%，但这没有考虑玻璃的具体组成，并且基于非常古老的研究。许多玻璃在此RH水平下继续腐蚀。不幸的是，RH的进一步降低会导致表面层剥落并从表面剥落，从而导致称为“卷曲”的毁容现象。虽然进一步水合与分层的推拉有时可以在存储中平衡到可接受的水平，但当涉及到与其他环境敏感材料（如有机物和金属）一起展示玻璃物体时，问题就复杂了，这需要不同的条件。此外，我们没有关于在发生龟裂之前可耐受的最低相对湿度水平的数据。英国遗产在其收藏中有大量的玻璃制品，其中一些处于恶化状态。本项目的目的是提供现代化的指导方针，存储英国遗产玻璃告知玻璃成分，水化率和分层的趋势。我们预计，这些准则将是有价值的古玻璃在其他机构，在英国和国际保管人。

Ancient glass corrodes through interaction with water in the soil or the atmosphere, losing alkalis and leaving a hydrated silica-rich weathered layer on the surface. Corrosion rates depend upon the composition of the glass and the ambient environmental conditions. When taken into storage, glass may continue to corrode unless the RH is low. The preferred RH value is typically cited as around 40%, but this does not take into account the specific composition of the glass and is based upon very old research. Many glasses continue to corrode at this RH level. Unfortunately further lowering of the RH can cause the surface layer to dehydrate and flake off the surface, leading to a disfiguring phenomenon known as "crizzling". While the pull and push of further hydration versus delamination can sometimes be balanced to an acceptable level in store, the issue is complicated when it comes to displaying glass objects alongside other environmentally sensitive materials such as organics and metals, which require a different set of conditions. Furthermore, we have no data on the lowest level of RH which is tolerated before crizzling will occur. English Heritage has large numbers of glass artefacts in its collections and some of these are in a state of advancing deterioration. The aim of the present project is to provide modern guidelines for storage of English Heritage glass informed by glass composition, rate of hydration and tendency to delaminate. We anticipate that these guidelines will be of value to custodians of ancient glass in other institutions, in the UK and internationally.