pieceful shade
maddie bean
what is eggshell?
Eggshells are primarily made of calcium carbonate (CaCO3). Eggshells also contain small amounts of phosphorus, magnesium, sodium, potassium, zinc, manganese, iron, and copper (Butcher and Miles, 2019).
An eggshell is covered in thousands of tiny pores and is made of CaCO3 crystals that form a semipermeable membrane, allowing air, moisture, and light to pass through (Exploratorium, n.d.).
Between the eggshell and the egg white are two transparent protein membranes that are partly made of keratin. These membranes defend the egg against bacterial infection and help to keep fragments together when the shell is broken (Exploratorium, n.d.).
eggshell as a material
CaCO3 is commonly found in rocks (most notably limestone) and is the main component of gastropod shells, shellfish skeletons, pearls, chalk, and coal balls (Omari et al., 2016).
CaCO3 is widely used for various industrial purposes, including as a filler and pigment material in paper, plastics, rubbers, paints, and inks. It is also used in pharmaceuticals, cosmetics, construction materials, asphalts, and as a nutritional substance in animal foods (Mattila and Zevenhoven, 2013).
Given the many uses of CaCO3 , it follows that eggshell is similarly versatile as a material.
limestone quarry
solid CaCO3 Union Process
eggshell-based precedents
Because natural eggshell acts as a semipermeable membrane, I decided to explore precedents that either enhanced or diminished this characteristic.
The Etoile Chandelier by Bourgeois Boheme Atelier is made of two rings of real ostrich egg diffusers connected by braided silk wire and illuminated by candelabra-sized bulbs (25 watt max). When lit, the eggshells transform into orbs that cast a soft, warm glow. This precedent shows that eggshells have a certain degree of translucency that could be leveraged in finish materials for light or ceiling fixtures.
Researchers at the Xi’an University of Science and Technology ground up eggshells, mixed them with stearic acid, and combined the mixture with zinc oxide particles, creating a solid substance that sheds water. The study indicated that this material could be used as a coating to keep surfaces clean and prevent corrosion and ice build-up. This precedent shows the potential of eggshells to be used to enhance the properties of finish materials such as paints, wall coverings, and coatings.
how does eggshell behave?
According to Awogbemi, Inambao, and Onuh (Heliyon, 2020), boiling has a negligible effect on the properties of a chicken eggshell. However, I found that boiling gave a faint white cast to brown eggshells.
It is very difficult to control how an eggshell cracks with any precision. The largest crack is usually at the point of contact with the object or surface used, with smaller cracks radiating outwards. Hitting the shell with a knife allows for a more controlled crack. When it is cracked multiple times, an eggshell splinters into random-sized, jagged-edged pieces. However, it is possible to make small, controlled holes in an egg shell using a sharp needle. If you make a hole on either end of the shell and poke a needle inside to break the yolk, then you can blow out the inside and are left with a relatively whole shell.
Loose eggshell fragments can be easily broken up into smaller and smaller pieces. The irregular shapes of these pieces are similar to the tiles that are used in mosaics. Eggshell can be further ground up to create a gritty powder. In fact, various studies have indicated that eggshell powder can be used to improve the cementitious characteristics of construction materials such as concrete, cement mortar, brick, and alkali-activated binder (Sathiparan, 2021).
Pillar pots by PRIOR SHOP Garderner’s Path
translucence versus opacity
My experiments showed that when an eggshell remains almost whole and a light source is placed inside, the shell becomes a luminous sphere that appears to be lit from within. The hole and therefore the light source must be quite small to achieve this effect - I used a battery-powered string of tiny LED lights. The actual amount of light given off by these egg lanterns is negligible, comparable to a nightlight.
However, when small eggshell pieces are placed on a comparably more translucent material, such as tissue paper, and light is shone through, the fragments take on the appearance of opaque solids. The closer the egg fragments are placed, the less light comes through. This effect suggests that eggshell could be strategically placed on a more translucent surface to act as a screening device.
material process
I landed on the idea of using tissue paper as a substrate, papier mache glue-based paste as a binder, and eggshell as aggregate. By layering substrate, paste, and eggshell on a solid base, such as a balloon, bowl, or a plastic sheet, I could create a variety of forms and shapes that, when illuminated from within, act as a shade or screen. Whole eggshells can also be reinforced with tissue paper and papier mache paste layers on their exterior and then lit from within for use as a small lamp.
playful purpose
Having decided that I wanted to create a eggshell-based material to be used in conjunction with light, either as a semi-translucent screen or shade, I created several iterations to demonstrate the potential applications of this material in an interior environment.
These explorations revealed that when incorporated into a translucent substrate material, eggshell fragments have a unique visual effect. Their jagged edges are irregular spots of near-opacity that draw the eye and contrast with the more uniform glow of translucence that surrounds them. Meanwhile, the egg lanterns highlight that eggshell itself allows some light to pass through, showing that large eggshell fragments could be pieced closely together, bound to a thin substrate material, and still admit some degree of light.
reflection on pieceful shade
Eggshell is remarkably versatile, as shown by the various studies that have confirmed its use as a beneficial additive to construction materials.
Because eggshell is naturally brittle and difficult to crack in a controlled manner, it makes the most sense to incorporate small shell fragments or eggshell powder into a new material.
By bonding an eggshell to a substrate like tissue paper using a glue-based wash, it is possible to reinforce the strength of the shell and make it more resistant to cracking.
Eggshell has the ability to be both relatively opaque and semi-translucent. Its opacity is highlighted when it is integrated with a more translucent material, in this case, tissue paper.
Sheets of pieceful shade could be layered to create a screen, shade, or wall-covering with a desired degree of translucency. The image on the above left shows a single layer of pieceful shade surrounding a light source, while the image on the lower left is a double layer.
The irregularity of the eggshell fragments adds visual interest to the finished material, and further blocks some light from being transmitted through it.
pieceful shade is reminiscent of shoji, the paper screens that are used in traditional Japanese architecture as doors, windows, or room dividers. It would be a suitable material for a similar usage.
references
Al Omari, M.M., et al. (2016). Calcium carbonate. Profiles Drug Subst Excip Relat Methodol., 2016 (41), 31-132. 10.1016/bs.podrm.2015.11.003 Anatomy of an egg. (n.d.). Exploratorium. https://www.exploratorium.edu/explore/cooking/egg-anatomy#:~:text=Eggshell%20is%20made%20almost%20entirely,keep%20out%20bacteria%20and%20dust.
An eggshell mixture that sheds water and shrugs off punishment. (2018, June 20). Nature. https://www.nature.com/articles/d41586-018-05499Awogbemi, O., Inambao, F., & Onuh, E. (2020). Heliyon, 6(10), e05283. https://doi.org/10.1016/j.heliyon.2020.e05283
Butcher, G. & Miles, R. (2019, February 20). Concepts of eggshell quality. University of Florida IFAS Extension. https://edis.ifas.ufl.edu/publication/VM013
Mattila, H.-P. & Zevenhoven, R. (2013). Production of precipitated calcium carbonate from steel converter slag and other calcium-containing industrial wasters and residues. Advances in Organic Chemistry, 66, 347-384. https://doi.org/10.1016/B978-0-12-420221-4.00010-X
Sathiparan, N. (2021). Utilization prospects of eggshell powder in sustainable construction material - A review. Construction and Building Materials, 293. https:// doi.org/10.1016/j.conbuildmat.2021.123465