Snap, Crackle, Pop: Plastics on Display
There is an ominous phenomenon at the National Communications Museum collection store. Every so often, small, symmetrical deposits appear on our shelving with no tracks leading to or from the scene.
Either a very small, very meticulous, tar-footed critter is roaming the shelves at night or the ‘feet’ on our collection items are melting.
Many of our items are mass-produced consumer items. They were built for the slamming of receivers after heated arguments, the winding of a cord around a starry-eyed converser’s finger and the inevitable dropping onto hard surfaces. These objects were built tough.
But they weren’t necessarily built to last.
As with many collections, our earlier items— those constructed of wood, metal and hard rubber components like ebonite and vulcanite mouthpieces — are relatively stable in storage. But with the widespread adoption and consumption of the new technology, telephone manufacturers sought cheaper materials and more efficient production methods.
From the 1910s, Bakelite hit the scene as more efficient alternative to wooden and metal telephone casings, becoming the dominant material of early 20th century telephones. Easily moulded, smooth and tough, Bakelite telephones proliferated in homes and offices across the world in classic ‘black’. The swinging 60s incited a sense of fun in our utilities. The era was heralded by the Ericofon and Colorfone series (constructed from an acrylic material, Acrylonitrile Butadiene Styrene), designed to complement your home décor. Telephones had become fashionable consumer products but fast fashion has it’s bite.
As the decades wore on and our love affair with electronic devices showed no signs of slowing, malignant plastics — such as polyvinyl chloride and polyurethane — were increasingly used in the manufacturing of our devices, eventually finding a home in museum collections.
The deterioration of plastics in our collection is one of the biggest conservation hurdles we must address before opening our doors this year. Indeed, there are some items in the collection that simply cannot be displayed safely lest they melt off their plinths.
But it is not all ooze over here. Just as there are many types of plastics — polyethylene, polyurethane, polyester, polyvinyl chloride and so on — there are many symptoms of plastic deterioration, both chemical and physical. Plastics can shrink, craze, crack, discolour, become brittle or tacky. These symptoms can be a consequence of the additives used in the manufacturing process — such as the plasticisers that make plastics malleable — but also the inherent characteristics of the material, as in the hydrolysis of cellulose triacetate plastic film base.
We mediate against the effects of environmental factors such as light, temperature and humidity by storing our items in dark, cold and dry storage. But museums — quite rightly, we think — are made for people not just objects. We need light to see, temperatures for human comfort and, preferably, we do not wish to desiccate our visitors or staff. Short of sending some plastic objects into orbit, there is no environment that will suspend all plastics in stasis for all time, least of all a gallery.
Let’s take a look at some of the patients.*
Constructed from the aforementioned ABS plastic, this object has only minor plastic deterioration in the form of photodegradation. Likely spending years in a window, this item has yellowed unevenly from UV exposure. While this discolouration is irreparable, the casing itself if sturdy and can be safely displayed. But this object isn’t out of the woods yet. Smaller components such as cords, dials, grommets are often made of malignant plastics, particularly polyvinyl chloride.
We’ll be keeping this item under moody lighting and watching closely for change in the colour and texture of plastic components during its time on display.
Most of the plastic components in this item are coexisting happily but polyurethane foam — a malignant plastic — is deteriorating faster than it’s peers. Posing a cleaning and OH&S dilemma (we don’t fancy breathing in plastic particles from the 1970s), the deteriorating foam can also cause staining of other components and lead to a loss of meaning or significance in the item.
While there may be no reversing the flaking foam, conservators can consolidate the remaining foam in a way that is sympathetic to the original object, thereby maintaining the integrity of the item and allowing for safe display.
These bloomy feet are a common sight at the NCM. While all may appear well up top — where inert and cooperative plastics reside — the rubber and polyvinyl chloride used in ‘feet’ are a canary in the coal mine.
We might not be able to reshape these problematic pedestals, we can work with conservators and mount makers to ensure that the item can be safely and securely displayed despite it’s predilection to toppling. We will also carefully monitor the other components of this item during it’s time on display, regularly venting any off-gassing of the polyvinyl chloride to avoid the build up of an acidic environment and corrosion of any metal casemates. We all need a good vent, now and then.
This telephone has hit the jackpot of polymer problems. With UV-induced yellowing of the wall plug, plasticiser or additive migration of the dial film, a brittle and cracked spiral cord and tacky wall plug, this object is a hot mess and not suitable for long-term display.
Fortunately, we have duplicates of this model that can be displayed while this chap heads back to the store, a haunting premonition of what will soon befall his mint-condition brethren.
Although the conditions of exhibition may accelerate the deterioration of some plastics in our collection, we feel that it is worth the risk to bring these objects to you — our adoring public. We are fortunate to have dozens of duplicates of landline telephones waiting in the wings to replace the inevitable cracked handset or tacky cord. For those objects without a younger, better-looking doppelgänger, we try to offer more protection through cases that buffer humidity, pollutants and light. This is why can’t let you touch all the objects.
We also believe that these objects offer far greater benefit as—albeit temporary — tools of education and engagement, than as relics of consumption, living out their ‘best before’ years on a shelf. Many of our duplicates are destined to melt, crack, discolour or bloom within our lifetime so why not go out with a bang!
But let’s not get ahead of ourselves. We still want to give our objects the longest life possible. This is where conservation comes to the fore. We conserve collection objects prior to exhibition not only so they look good on display, but so their display doesn’t cause harm to the item or other objects in its vicinity.
To ensure our objects to look nice and play nice this year, we will be preparing our display items — including a few pictured here — in partnership with the Grimwade Conservation Centre. Keep an eye out on the NCM socials for case studies and behind the scenes pics.
*For their privacy and so as not to steal the thunder of our curatorial team, most of these objects have been deidentified. You’ll have to visit us to find out what they are!