Presentation on theme: "1 Causes of deterioration Poor quality of modern paper: Good paper can survive longer, strong and stable enough to withstand wear and tear Modern paper."— Presentation transcript:
1 Causes of deterioration Poor quality of modern paper: Good paper can survive longer, strong and stable enough to withstand wear and tear Modern paper manufacturing can produce permanent and durable paper by: using long fibres, Removing all chemical residues left from the pulping process, Using better sizing, Removing all bleaches
2 Causes of deterioration 2. Materials used in modern book production, e.g. leather, cloth, thread, glue, ink have chemical properties whose interaction and reaction to the paper may increase the rate of deterioration Binding: Weak points in a book include Hinges which link the boards and the spine Sewing or adhesive links the binding with the body of the book Some bookbindings are of historical interest and art value, and should not be replaced and the books be re-bound.
3 Causes of deterioration 2. Materials used in modern book production: Use of inappropriate substances e.g. light boards, low-quality sewing thread in book binding will cause deterioration even if the book is merely standing on the shelf. Adhesion of PVA glues is difficult to reverse, Pastes made from wheat or rice starches is reversible with water, but they are nutrients for insects and pests. Pressure-sensitive tapes e.g. Scotch tape, are hard to remove and often leave permanent staining
4 Causes of deterioration 3. Materials of information storage: Photographic materials, e.g. photographs, negatives, lantern slides, films: Are easily damaged by light and air due to the very nature of the materials and the chemical processes used in their creation. Photographic media, for all sound and digital media and microfilms require reading and viewing equipments.
5 Causes of deterioration 3. Materials of information storage: Digital media needed to be kept in usable condition, and it involves the issue of selecting digital materials for preservation. Nitrate-based films create fire hazard, storage conditions are important. Making copies brings about the issue of quality of a second- or third-generation copy and the choice of data migration. Discard the originals after reformatting?
6 Causes of deterioration 4. Increased use of library collections accelerate the rate of deterioration: Librarians promote use of and accessibility of library collections, e.g. books shelved in open stacks, inter-library loan, book drops, resource sharing and bibliographic networks (union catalogs). Book drops and book return chutes cause mechanical damage to bindings Extension of leisure reading and education,
7 Causes of deterioration 4. Increased use of library collections accelerate the rate of deterioration: But librarians have not seriously considered the implication to preservation Mass production of cheaper paperback, acidic paper made from ground wood pulp are glued to a light card cover by an adhesive, the paper discolours and becomes brittle, the adhesive cracks, pages fall out, the cover bends and fails to offer any protection to the front and back pages
8 Causes of deterioration 5. Damage by use: Opening a book puts a strain on the binding, Handling by users and staff in reading, shelving, careless reading habits, thoughtless handling Use of large tables and book rests in reading in the proper supervision of trained staff is a possible solution, e.g. in archives, When the items are exhibited, conditions within the display case (temperature, relative humidity, light, etc.) and use of special book rests, page weights, etc. have significant impacts on the materials.
9 Causes of deterioration 6. Photocopying: Mechanical stress from opening out the binding and pressing down the book light and heat speed up the rate of deterioration,
10 Causes of deterioration 7. Air pollution: Concentrations of air pollutants such sulphur and nitrogen oxides in polluted air produce acids which speed up the rate of deterioration, irreversibly break down the molecules from which paper, fabrics and leather, derive their mechanical strength, Gaseous pollutants cause fading and discoloration of photographic materials, some pigments and dyes
11 Causes of deterioration 7. Air pollution: Dust and dirt particles cause mechanical damage through abrasion with the paper, Dust and dirt particles cause dust accumulations and soiling, Food, dust and dirt are food for insects and pests, this leads to infestation
12 Causes of deterioration 8. Accidental and deliberate damage: Natural disasters e.g. fire, floods, earthquakes Acts of vandalism, e.g. war, terrorism, removal and cutting of pages/articles from books/journals, marking of a textbook, e.g. pencil marks and highlight, theft,
13 Causes of deterioration 9. Wrong attitudes towards books: Low standards of care and handling among staff and users Librarians neglect: the pattern of cause and effect in storage, exhibition and use, e.g. lighting, temperature and relative humidity control allow destructive procedures to continue,
14 Causes of deterioration 9. Wrong attitudes towards books: Use of inappropriate repair techniques which have caused more harm than good, e.g. use of book tape and lamination is irreversible, Books can readily be replaced by photocopying and from commercial vendors, When building a library, planners only consider the standards of lighting and heating for users and neglect the physical requirements needed to slow down deterioration rate of library collections.
15 Causes of deterioration 10. Temperature and relative humidity: High temperature and relative humidity speed up deterioration, encourage the growth of molds and fungi which damage materials The rate of chemical reactions is almost doubled with each increase in temperature of 10 °C,
16 Causes of deterioration 10. Temperature and relative humidity: Heat affects the rate at which chemical reactions occur, Heat affects the physical structure of library materials (e.g. vinegar symptom in microfilm materials) Heat evaporates water, dryness causes brittleness in paper, leather and some plastics
17 Causes of deterioration 10. Temperature and relative humidity: Rapid changes in temperature causes expansion and stresses on the materials which leads to damages, Sudden drop in temperature may cause water condensation on the surfaces of items whose temperatures have dropped, High RH causes water-soluble inks to run (blur), and paper (glossy) which is coated with china clay or chalk to stick (e.g. illustrations) Very low RH cause many materials to shrink,
18 Causes of deterioration 11. Light (sunlight, fluorescent light and ultraviolet light): Ultraviolet light is the most harmful to library materials, Sunlight through windows and light from lamps cause heating of the space, local warming and desiccation of objects that the light falls on, Light is radiant energy which can speed up deterioration, the rate of oxidization, hastens chemical breakdown, weaken the strength of paper, textiles, and leather,
19 Causes of deterioration 11. Light (sunlight, fluorescent light and ultraviolet light): Light causes color and image fading, bleach paper and inks Light reacts with lignin and darken the paper, e.g. yellowing of newspapers Absence of light is beneficial for all library materials
20 Causes of deterioration 12. Biological agents: Molds and fungi grow when condition is favourable: temperature at/above 25 °C relative humidity above 60%, darkness and poor air circulation Nutrients for molds and fungi are found in leather, vegetable paste, cellulose, sizing or gelatin emulsions on photographs, solid particles in polluted atmospheres
21 Causes of deterioration 12. Biological agents: Molds weaken and stain paper, obliterate (blur) images on paper and on photographic materials, react with trace elements in paper, produce small brownish patches (foxing) in books (usually on end paper)
22 Causes of deterioration 12. Biological agents: Insects e.g. cockroaches, silverfish, termites, book-lice and beetles, spiders, rodents (mice) Insects feed on organic substances e.g. cellulose in paper, pastes, glues, gelatin sizing, leather and bookcloth, Warm, dark, damp, dirty and poorly ventilated conditions are favourable living conditions for insects,
23 Causes of deterioration 12. Biological agents: Damage caused by insects is usually irreversible, e.g. holes and images eaten through books and photographs. Handout 1 Harvey, Ross (1993) Preservation in libraries : principles, strategies, and practices for librarians. London ; New York : Bowker-Saur. P.46
24 References Feather, John (Ed.). (2004).l Managing preservation for libraries and archives : current practice and future developments. Aldershot, Hants, England ; Burlington, VT : Ashgate. Harvey, Ross (1993) Preservation in libraries : principles, strategies, and practices for librarians. London ; New York : Bowker-Saur