Conservation (9): Deterioration of plastics

Plastics are synthetic or semi-synthetic materials that can be processed to form a wide range of objects, from thin films and foams to large, high-strength 3D objects. Plastics are based on polymers, which are large molecules made from many smaller ones joined together. There are roughly 50 different basic types of polymers used in approximately 60,000 plastic formations. The annual production of plastics has risen dramatically in the past years, from 5 million tonnes in the 1950s to almost 100 million tonnes in early 2000. In 1982, the production of plastic surpassed that of steel and, as such, that year has been signalled as the beginning of the ‘Plastic Age’.

Plastics in the HIV/AIDS Collections  

The proliferation of plastics in contemporary life is reflected in this modern collection. The following plastics are frequently found.

• 3.5” floppy discs and CDs used to store information from a computer
• Sound and image recordings such as vinyl records, VHS and audio cassette tapes
• Photographic materials such as colour photographs, negatives and film reels
• Condoms and condom/pill cases
• Balloons, bags, badges and watches used in health promotion campaigns
• Photocopies and faxes use plastics in the form of co-polymers mixed with carbon black, fused to the surface of the paper
• Plastic enclosures such as ring binders and poly-pockets previously used to store the material

A severely degraded balloon that has become stuck to a business card.

Degradation processes

Plastic degradation can be defined as any physical or chemical change that results in the loss of the function and form of the object. Deterioration of plastics can be caused by physical and chemical factors.

Physical factors

The mechanical use of plastics relates to degradation caused by handling or use of an object. For example, the incorrect handling and repeated bending of a plastic doll may result in stress fractures or breakages.

Migration of additives: Plastics contain additives called plasticisers that increase the flexibility of the object. However, as the object ages, the plasticisers evaporate, causing it to become more brittle. This can be particularly problematic if the plasticisers are absorbed by another material in close contact with the object. The photograph below shows a window sticker that has degraded, releasing plasticisers which have in turn been absorbed by the plastic pocket it was previously stored in, resulting in deformation of the pocket. 

A ‘no smoking’ window sticker that has released plasticisers as it has degraded. These have been absorbed into the poly pocket and have resulted in deformation.

Chemical factors

The following factors provide the energy and the environment to promote destructive chemical processes which break the bonds within polymers, resulting in loss of strength, increased brittleness and discolouration.

Light: Ultraviolet light is most damaging to plastics and causes discolouration and increased brittleness. This is due to chromophores in the polymer chain absorbing light and catalysing photodegradation.

Heat: A temperature change can change the physical characteristics of plastics. As the object is heated, it will become more flexible and may distort when handled. The point at which this occurs changes depending on the polymer. Heat also increases the rate of chemical reactions in the object. Heating a plastic object also breaks the bonds in the polymer chain. This is known as depolymerisation and results in a loss of strength.

 

Oxygen: Plastics can react directly with oxygen (auto-oxidation) or with ozone (oxidation). Ozone is a highly reactive material derived from the reaction of oxygen with ultraviolet light. These oxidation processes can, again, cause the breaking of bonds within a polymer and result in loss of strength and brittleness.

Effects of plastics in archives

Plastics not only form part of the HIV/AIDS collections, but are also used to house paper materials. For example, polypockets, ringbinders and spiral bindings are all used to collate and store loose paper in the collections. These plastics are not chemically stable and release damaging acids as they degrade over time. Office ringbinders can be especially problematic as they are frequently made from PVC (polyvinylchloride) which emits hydrochloric acid over time. This acid is readily absorbed by paper materials and can cause them to degrade.

Due to this, all paper materials have been removed from these folders, but reference samples have been kept separately so that the original look and function of the collection items can be recreated if necessary.

An example of a ring binder with poly pockets used to store loose paper in the HIV/AIDS collections.

 A zip lock bag used to store a collection of paper materials from the Take Care campaign.

Conservation of Plastics

The deterioration of plastics is ongoing and irreversible; therefore, preventive care is the best option for this type of material. This involves choosing the best possible storage conditions and handling practices to slow down deterioration and reduce the risk of further damage.

Handling

Plastics should be handled using nitrile gloves. Cotton gloves should not be used, as this can leave specks of lint on plastics that have become tacky.

Environmental conditions for plastics

Plastics should be stored in a cool, dark, dust-free area. The temperature should be kept at 20 degrees centigrade and the relative humidity at 30%-50%.

All UV light should be filtered out and light levels should be kept low during display.

Storage

Plastics should be stored on shelves with good ventilation. The object should not be stored in completely sealed boxes, as acidic vapours released from the object will become trapped and result in a concentration of acids. Plastics can be wrapped in acid-free tissue. However, this is problematic as degrading (and tacky) plastics may become stuck to the tissue.

It is best to store similar plastics together as different plastics will emit different gases, which may adversely affect other objects. While this is not always possible, an activated charcoal cloth can be used to absorb any vapours released from the plastics and prevent them from harming other materials close to the object.

Plastic objects should be regularly inspected for signs of deterioration, such as crazing, discolouration or tackiness. If degradation is suspected, the object should be isolated from other objects.

Plastic objects in the HIV/AIDS collection

The plastics in this collection are in relatively good condition. However, the storage materials used were not of sufficiently high specification. To improve this, the following actions were carried out:

• Holes were cut into the side of the box to increase ventilation
• An activated charcoal cloth was used to line the bottom of the box and absorb any acidic vapours
• Card walls were used to separate different objects to aid in locating the objects and reduce handling
• Items were placed in inert polyester pockets with one edge left open to protect the object, but allow ventilation

Photographs of plastic objects before and after treatment.

Spotlight On (11): Portrait of Dr Elsie Inglis

Elsie Inglis (1864-1917) is of great importance to the history of medical care for women in Edinburgh. She founded a seven bed maternity hospital for poorer women in 1899, which moved to the High Street and became known as the Hospice five years later.

Portrait of Dr Elsie Inglis, c. 1915.

But it was for her work during the First World War that Inglis became famous. She had the inspiration for the Scottish Women’s Hospitals for Foreign Service and it went on to send hospital units to France, Serbia, Russia, Corsica and Greece. She died in 1917 and after the Scottish Women’s Hospitals disbanded it was decided to use the remaining funds to build a hospital in her name. The Elsie Inglis Memorial Maternity Hospital opened in 1925.

The portrait above, part of the LHSA object collection (LHSA ref: P042), shows her in her Scottish Women’s Hospitals uniform in a drawing by A Montefiore Micholls.

Conservation (8): Conservation of modern collections

It is often assumed that modern collections, such as LHSA's HIV/AIDS material, do not need conservation treatment. However, this material is still vulnerable to deterioration because of its inherent qualities or inappropriate storage methods upon accession. Often, modern collections in archives consist of unstable or low-quality materials, as they were not designed to last but sewere intended for practical and temporary use.

For example, modern paper made from low-quality materials may exhibit greater deterioration than an older paper object made with high-quality rag paper. Plastics formed 20 years ago may already be fading or becoming brittle, and modern materials such as VHS and audio tapes could be unreadable after just a few decades.

Problems can also arise with mixed media collections regarding how to store these items together in their original form without losing their meaning, while still adhering to conservation standards. Ethical issues also emerge, such as which items to retain and which can be disposed of. Questions about conserving modern materials will only grow as more modern ones are produced daily, making this a new and fascinating area.

Example of unsuitable housing of collection items upon accession.

Conservation of modern paper

Deterioration of modern paper

Often paper made in the past 50 years shows greater deterioration than papers made 500 years ago. For example, this newspaper page (right) found in the HIV/AIDS collection has discoloured and become brittle.

Paper deterioration can be caused by both internal and external factors.

Internal causes of paper deterioration

The raw materials and the manufacturing process of paper can cause degradation. 

Raw materials

In Europe, early papers were made from cotton, linen and hemp rags which were relatively stable and generally made good quality papers. However, as the demand for paper grew, papermakers began to use different materials and methods which resulted in lower quality sheets. In the 1840s, a method was developed for using ground wood pulp in the paper making process. This type of pulp contains lignin which is acidic and darkens on exposure to light.

The use of new materials, such as recycled fibres, optical brighteners and colourants and new manufacturing processes from the 1980s onwards has increased the types of paper available. However these processes and material all have an effect of the longevity of the paper and a paper conservator must be aware of the methods of production to successfully treat objects made from modern paper.

A newspaper that has discoloured over time, especially along the edges and folded areas.

Manufacturing process

Early papermaking was all carried out by hand, which resulted in a good quality strong sheet. However, it was a long and laborious process and many sought to mechanise the manufacturing procedure to increase production.

The first papermaking machine was invented in 1798 by Nicholas-Louis Robert. This mechanical pulping and formation resulted in shorter fibres and also unintentionally introduced metallic particles into the paper resulting in a weaker sheet.

Chemical pulping was introduced in 1854 by Hugh Burgers and Charles Watt. Chemical pulping removes lignin and does not cut up the fibres as much as mechanical pulping, resulting in a stronger paper.

From the mid-1970s thermomechanical pulping was widely used. This method uses heat and mechanical pulping to soften the wood chips used in paper making. Today, the sulphate process is most commonly used to produce paper. This is a chemical procedure in which wood chips are treated with sulphurous acid under high pressure to produce cellulose and extract lignin.

Alum rosin sizing was introduced in the early 18th century in an attempt to strengthen the paper; however, this sizing caused further acid to form within the paper. Wood pulp paper from before the 1980s also tends to be acidic due to the alum-rosin sizing used. The development of synthetic sizing in the 1980s enabled the production of paper with a neutral to slightly alkaline ph. This, combined with a calcium carbonate filler, acting as an alkaline reserve to prevent acid contamination from the environment, resulted in paper with better ageing characteristics than modern papers from the early 20th century.  

This resource by the Robert C. Williams Museum of Papermaking provides a good overview of the history of papermaking around the world: History of Papermaking Around the World

External causes of paper deterioration

Environmental conditions

Temperature: high temperatures increase chemical reactions. An increase of 10 degrees C doubles the reaction rate. Therefore, a cooler environment is preferred for paper collections.

Humidity: moisture in the air can also accelerate chemical reactions. High levels of humidity can aid mould growth and encourage pests. Equally, low levels can cause desiccation of the object and result in increased brittleness.

Fluctuation of these conditions causes the material to expand and contract. Over a long period of time, this can weaken the physical bonds within the paper and cause a loss of strength.

Pollutants

Gaseous pollutants can originate externally from industrial and vehicle fumes, or internally from common materials such as paint, plastics, cleaning supplies, and photocopiers. These pollutants, especially when combined with a humid atmosphere, can initiate chemical reactions that can result in paper degradation.

Light

The absorption of energy from light can trigger chemical reactions that degrade paper. UV light is particularly damaging as it has more energy than other longer wavelengths of light. Light can cause the lignin in paper to darken and cause inks and dyes to fade. Other forms of light such as direct sunlight and infra-red bulbs can also produce heat which again causes paper to degrade.

Handling and storage

In the HIV/AIDS collection, the majority of the damage to the paper documents is due to poor handling and storage during use, prior to accession. They were often used in offices and, as such, not handled with great care as they were just seen as ephemeral documents.

Paperclips and staples

Frequently, metallic paper clips or staples are used to hold loose sheets together; however, these can rust over time and cause planar distortion of the paper. These damaged areas now represent an area of weakness, which will be more susceptible to damage over time.

Creasing

Due to inappropriate storage and careless handling, papers can easily become creased. These creases weaken the paper fibres and may be more likely to tear in the future. This is often caused by inappropriate storage. For example, documents placed in a ring binder may exhibit tearing around the hole punches.

Tears

This is often caused by inappropriate storage. For example, documents placed in a ring binder may exhibit tearing around the punched holes.

 

Surface Dirt

Although it may seem innocuous, surface dirt can absorb pollutants from the atmosphere. These can then migrate into paper and increase the acidity of the paper. Surface dirt can also provide a food source for pests and encourage mould growth. Without appropriate storage, dirt can accumulate on the paper surface and result in paper degradation.

Conservation of modern paper

Surface Dirt 

Surface dirt has been removed using a chemical sponge. This method was chosen as it is quick and easy to prepare. It can also be used to target specific areas and is very effective at removing surface dirt

Removal of metal fasteners

In the HIV/AIDS collection, metallic fasteners such as paper clips and staples are frequently used to hold together loose sheets of paper. These items are all being removed to avoid the transfer of rust from the metallic fastener to the paper. Care must be taken to avoid the tearing of the paper during removal. 

Once these metallic fasteners have been removed, the nature of the object has been slightly changed and it may not be obvious that these items were previously held together. Therefore, simple paper tabs have been created to hold items that have had their metallic fasteners removed together. The number of metallic fasteners that have been removed has also been recorded so that the original appearance of the items can be recreated if necessary.

Creasing

Creasing has been reduced by gently rubbing the creased area with a bone folder over a piece of Bondina™. In some cases of extreme creasing, the paper has been carefully folded back on itself to help the fold lay flat. In most cases, the papers have been laid flat in the archival folders so that over time they will lay flat due to the weight of other paper items on top of them. In cases of extreme cockling, paper items have been placed in a press between layer of Bondina™ and blotter to reduce planar distortion.

Tear Repair

Tears have been repaired using Japanese paper and wheat starch paste.

Rehousing

All paper items are being rehoused into more suitable enclosures to provide better protection from mechanical damage and to avoid migration of acids from non archival storage methods.

Due to the size of the collection, it is not feasible to house each sheet individually. Instead, loose papers at a maximum depth of 2 cm are placed in triptych folders. These folders are then placed in acid free clam shell boxes.

Postcards from the Take Care HIV awareness campaign

The Take Care campaign in Lothian began in the late 1980s in response to the realisation that cases of HIV and AIDS in the area were four times the national average, affecting mainly young heterosexual people. The campaign aimed to raise awareness among all community members and involved advertising, events, and educational initiatives.

The postcards below display some of the images that were used in the campaign to portray the message of safe sex and 'taking care of the one you love'. The Take Care collection came to LHSA in 2000. It consists of administrative files, information packs, reports and research, advertising materials, postcards and posters, audiovisual items, and objects.

In 2015, resources for teachers in secondary schools and youth groups were introduced largely based on this collection. The resources focused on the Curriculum for Excellence framework. Each resource highlights specific items within the HIV/AIDS collection at LHSA. A fact sheet provides background information on the resources presented, along with suggested activities.

Take care of the one you love. Condoms can prevent.... (GD22/14/4/2/28).

Take Care of the One You Love, 1990s (GD22/14/4/3/1).

Do you come here often?, 1990s (GD22/14/4/1/2).

Lovely latex, 1990s (GD22/14/4/3/3).

If he’s half as big as he thinks he is….10.5 x 14.5 cm (GD22/14/4/5/14).

If they’re half as fashionable as they think they are…. 10.5 x 14.5 cm, 1990s (GD22/14/4/5/15).

You are the sunshine of my life, 1990s (GD22/14/4/3/8). 

Take Care when you xxxx, 1990s (GD22/14/4/3/11).

The Royal Edinburgh Hospital's Royal Charter

King George III granted a Royal Charter in 1807, establishing the Edinburgh Lunatic Asylum. The foundation stone of the original building was laid in 1809, and the first patient was admitted in 1813. The charter is in Latin and has the Great Seal of Scotland attached. LHSA created three posters capturing the Royal Charter in advance of the Hospital's bicentenary celebrations in 2009.

In 1792, Andrew Duncan initiated an appeal to establish an asylum in Edinburgh. Voluntary contributions were initially slow. However, a government grant of £2,000 in 1806 significantly increased the funds and allowed for the purchase of a villa and four acres of surrounding land in Morningside. Soon after, in the spring of 1807, a Royal charter or warrant granted by His Majesty King George the Third established the Edinburgh Lunatic Asylum (ELA) as a corporate body. The foundation stone of a building designed by architect Robert Reid was laid on 8 June 1809. ELA admitted its first patient on 19 July 1813.

Pages of the Royal Edinburgh Hospital's Royal Charter of Incorporation (LHB7/19/12/21).

As well as extending royal patronage, the warrant made ELA into a public body. This gave legal rights to use a common seal, to perpetual succession, to sue and be sued, to own lands, to lend money and to receive donations and legacies. It could also make bylaws, rules and regulations, provided they were consistent with the institution’s charitable purpose.

The warrant also specified how ELA was to be run. Twenty named extraordinary managers and twelve named ordinary managers were elected. They were drawn from the Edinburgh Town Council, the law, the University and the local medical profession. A governor and five deputy governors, along with four ordinary managers, could be chosen from among charitable contributors who had given £10 or more and who resided in or near Edinburgh.

Front and back image of the Great Seal (LHB7/19/12/21).

The warrant consists of four sheets of parchment folded to make eight pages. The text, in Latin, is inscribed onto each page except the last, which is blank. The Great Seal of Scotland is attached using intertwined silk threads. Its wax relief shows King George in military uniform, mounted on a rearing stallion and overlooking the City of Edinburgh. An idealised, but still identifiable, panorama of the Castle, the churches and tenement buildings of the Royal Mile and Salisbury Crags can just be made out behind the horse’s legs. 

In 1841, Queen Victoria allowed the prefix ‘Royal’ to be added and, ten years later, the name was officially changed to the Royal Edinburgh Asylum by a private Act of Parliament. In 1927 a new charter was obtained which changed it to the Royal Edinburgh Hospital for Mental and Nervous Disorders. Today it is simply known as the “Royal Edinburgh”. 

A new building, designed by William Burn, was added in 1842. Originally known as West House, it was later renamed after Dr William M’Kinnon, who served as the first Resident Physician from 1839 to 1846. Additional accommodation was added in 1894 when Craig House opened nearby. The original building, soon called East House, was eventually demolished. During the twentieth century, the site saw a series of outpatient and residential developments. The Royal Edinburgh Hospital was granted a Coat of Arms in 1959. 

Further resources

Poster 1: General information about the Charter and Seal

Poster 2: The Charter text in English

Poster 3: Images of the Charter and Seal

History of the NHS (2): The dawn of a new era

In 2008, a photographic exhibition by LHSA celebrated the 60^th anniversary of the National Health Service.

The National Health Service (NHS) was launched on 5th July 1948. It heralded a new era of health care for the UK. The main provision was for every man, woman and child to have access to a complete health service, regardless of who they were or where they came from. Medical care and treatment were to be free to all individuals, funded by central taxation.

Back cover of Royal Infirmary of Edinburgh League of Subscribers Annual Report, July 1948 (GD1/38/6).

Leith Day Nursery, South Fort Street, c.1950s (LHSA Photographic Collection) [Image reproduced by permission of The Scotsman Publications Ltd.]. The NHS strengthened and consolidated maternity and child welfare services, which were first established in Scotland at the turn of the century. As well as providing clinical care for expectant mums, babies and young children, it offered further assistance to mothers through ante-natal classes, health visitors, nurseries and play centres.

Sighthill Health Centre, c.1950s. Sighthill Health Centre opened in May 1953 and was the first of its kind in Scotland. Sighthill was chosen because it was a new housing area with a large population that was inadequately served by existing provision. he idea behind it was to create a facility for related health care services under one roof. The Centre housed GP consulting rooms, child welfare and school health services, an NHS dental surgery, a pharmacy and a physiotherapy department.

The NHS brought together a number of existing services which had begun many years before. It provided a uniform national structure that had previously involved voluntary, provident, private and government provision at the hospital and community levels. The main features were: regional hospital boards to co-ordinate hospital services; local health authorities to run community-based services and executive councils to administer GP, dental, chemist and eye services. The complete service offered by the NHS aimed to encompass all aspects of health care from the cradle to the grave. It also promoted good health and welfare in general.

National Health Service (Scotland) Act, 1947. The text reads, 'Chapter 27. An Act to provide for the establishment of a comprehensive health service in Scotland, and for purposes connected therewith. [21st May 1947.]'

Newspaper cartoon, c.1946 (LHSA Pamphlet Collection). This cartoon shows an elderly patient worrying about the potential effects of the new National Health Service. The British Medical Association agreed with the creation of the NHS in principle, but felt it was not properly consulted when the legislation was being developed.

People playing cards and dominos at Sighthill Health Centre, c.1950s [Image reproduced by permission of The Scotsman Publications Ltd.].

Before the NHS, citizens had to pay for medical advice and treatment. Many simply could not afford this. So calling out a doctor, or going to a hospital, often became a last resort, with the result that illnesses or injuries often went untreated altogether, or became more serious than they might have been. The NHS meant that people of all classes no longer had to worry about how they would pay. Care and treatment became a right, not a privilege.

Royal Edinburgh Maternity Hospital (Simpsons) Case Note, 1935 (LHB3 CC1/ 1935/1010). This image is taken from a patient case note and shows a husband and wife's pre-NHS insurance provision. The National Health Insurance Scheme was introduced as part of the National Insurance Act of 1911. It entitled the working man (and in some cases his family) to medical treatment, his wife to maternity care and offered him sickness benefit during periods of his incapacity for work. By the mid-1930s, all manual labourers earning no more than £250 a year were made compulsory members of the Scheme.

Nurse and patient in ambulance, 1942. Before 1948, the ambulance service in Scotland was supplied jointly by the St. Andrew's Ambulance Association and the British Red Cross Society, and funded by voluntary contributions. This joint service continued post-1948, the only change being that the costs were now met by the State.

School Dental Service, c.1950s. Dental check-ups and treatments were free under the early NHS, as were visits to a GP, eye tests and spectacles, hearing tests and hearing aids.

The first part of the exhibition focuses on aspects of pre-1948 health care and selected features of the NHS Scotland Act. The second part provides photographic snapshots of the many components of the service provided by the NHS in Edinburgh.

Royal Edinburgh Hospital Admission Register, 1920 (LHB7/35/12). These volumes recorded several patient details, including an individual's status as 'private' or 'pauper'. If private, the patient or their family would be charged an appropriate board rate. If a pauper, the state would pay the minimum for their care under the provisions of the Scottish Poor Law. Private patients in this psychiatric hospital were housed separately from paupers in finer surroundings and had access to many other privileges which paupers were excluded from.

The NHS has adapted and developed continuously since 1948. Almost immediately, it became apparent that the need for health care in Scotland (and the UK) was enormous and that the cost of meeting it was going to be far higher than previously estimated.

School Medical Service, diphtheria immunisation, 1953. In Scotland, the School Medical Service was established in 1908. For the next 40 years, it was administered and financed at a local level, often with very limited resources. With the coming of the NHS, medical services for school children became the responsibility of the State nationally. It soon began to offer vaccinations and immunisations to all children.

Royal Edinburgh Hospital Case Book, 1916 (LHB7/51/100). This image shows the higher annual board rate paid by this private patient. Despite staff working hard to improve the mental health of all patients, fundamental inequalities remained.

Many people today are quick to associate the NHS with waiting lists, prescription charges and so-called ‘postcode lotteries’. But we should never forget that the fundamental values behind the NHS still remain the same. Anyone who is sick or injured can go to a hospital or a doctor’s surgery and get the help that they need. This was not the case 60 years ago in Scotland and is unfortunately not so in many countries of the world today.

Hospital ward, East Fortune Hospital, 1953. East Fortune Hospital was a tuberculosis sanatorium which opened in 1922. It was converted for this purpose from a World War One naval airship station in Drem, East Lothian. From 1956, the hospital also began to care for children and adults with learning disabilities.

Audience receiving question cards at a health education meeting, New Victoria Cinema, 1947. Health education was not just for mothers and children. Public meetings held in cinemas were organised by the Edinburgh Public Health Department, now a fully integrated part of the NHS. Films were shown followed by question-and-answer sessions on a range of topics. For example, tuberculosis, venereal disease, hygiene and exercise. Anybody could attend without charge.

The 'Audience of 2000' leaving the New Victoria Cinema after a health education meeting focusing on tuberculosis, 13 March 1949 [Image reproduced by permission of The Scotsman Publications Ltd.].

Central Leith Health Campaign, 1955 [Image reproduced by permission of The Scotsman Publications Ltd.]. In the 1950s, Edinburgh worked hard to promote the fight against tuberculosis. The Central Leith Health Campaign of 1955 encouraged people to have their chest x-rayed to detect any signs of the disease. This was followed in 1958 by the Mass Radiography Campaign, which invited all citizens of Edinburgh over the age of 15 to have their chests x-rayed. A staggering 77% of the population took part.

Central Leith Health Campaign, 1955 [Image reproduced by permission of The Scotsman Publications Ltd.].

Window display at Woolwoths, Princes Street promoting 'Health Week', 1952 [Image reproduced by permission of The Scotsman Publications Ltd.]. Edinburgh's 'Health Week' ran from 10th to 18th May 1952 and employed the slogan 'Your Health is Edinburgh's Wealth'.