12.04.2024
BASIS REZEPT/EXPERIMENT 1
30g rice starch
7.5g glycerol
100ml distilled water
15ml vinegar
____
PREPARATION:
measure the distilled water, glycerol & vinegar, pour into a pot and stirr
slowly add the rice starch -> stirr continuously for two minutes with a whisk at 60 degrees Celsius
pour into two petri dishes
distribute evenly with a spoon
____
OBSERVATIONS:
thickens quickly when heated, state when poured into the petri dish - creamy thick & white color
after 5 min: same state
after 20 min: completely cooled, surface matt, upper layer pudding-like (spread test) lid (on a petri dish) -> immediately removed (condensation -> not yet fully cooled)
after 36 min: lid on the petri dish
____
EXPECTATIONS:
elastic, pliable, solid material.
____
One dish with lid/cover and one without
EXPERIMENT 2
15g rice starch
15g banana powder
7.5g glycerol
100ml distilled water
15ml vinegar
____
PREPARATIONS:
measure the distilled water, glycerol & vinegar, pour into a pot and stir
slowly add the rice starch and banana powder -> stir continuously for two minutes with a whisk at 60 degrees Celsius
after 8 minutes of whisking -> too liquid state = due to the banana powder, add another 15g rice starch
whisk for 4 minutes
remove pot from the stove
whisk for 3 minutes without heat
pour into two petri dishes
distribute evenly with a spoon
____
OBSERVATIONS:
Starch did not clump (just as in Exp. 1)
banana powder initially formed many small mini lumps -> dissolved by whisking
state when decanting - creamy liquid, grey beige, initially air bubbles
____
EXPECTATIONS:
a more elastic substance (than in Exp. 1) -> banana powder acts as a gelling agent, mould (banana)
____
One dish with lid/cover and one without.
19.04.2024
CATCH UP
(12.04.) Experiment 1: (picture 1)
with lid - state unchanged: still liquid/creamy consistency, white colour
without lid - state: rock hard at the top (hard plastic) & slightly rubbery at the bottom (not yet completely dried), milky transparent, broken structure/individual chunks, strong reduction of mass
____
(12.04.) Experiment 2: (picture2)
with lid - state unchanged
without lid - state: beige brown colour (slightly lighter), firm - yields only slightly when pressure is applied with a finger & pressure marks appear when hard pressure is applied with a fingernail, elastic - can be bent but tears quickly, smooth surface, leather-like to the touch, white dots = air bubbles, mass only slightly reduced The target state of the final material based on this: Elastic, pliable, without tearing
PLAN
Experiment 3 - xanthan instead of banana powder
Mini - Experiments 1 & 2 - exposure of fragments from Exp. 1 & 2 to test water resistance/absorbability
MINI - EXPERIMENT 1
petri dish with distilled water
chunks from the first experiment (12.04.)
____
OBSERVATIONS:
After 5min - becomes soft
After 15 (17)min - small particles (white) soak off
After 30min - more pieces soak off
After 60min - upper hard part unchanged, rubbery part (bottom) very soft
MINI - EXPERIMENT 2
petri dish with distilled water
chunks of the second experiment (12.04.)
____
PREPARATIONS:
After 5min - becomes soft, sticks slightly to the bottom
After 15 (17)min - upper layer brown, lower layers become beige/lighter in colour
After 30min - much lighter/somewhat lighter than at 15min, top layer still firmest = takes longer to absorb water since the layer was completely dry
After 60min - all soft, water is milky
EXPERIMENT 3
15g rice starch
15g xanthan
7.5g glycerol
100ml distilled water
15ml vinegar
____
PREPARATIONS:
measure the distilled water, glycerol & vinegar, pour into a pot and stir together
slowly add rice starch & xanthan -> stir continuously with a whisk at 60 degrees Celsius
whisk for 1 min: Yeast dough-like consistency
pour 1/4 into a petri dish and large silver collecting dish
distribute evenly with a spoon
____
EXPECTATIONS:
more pliable material than in Exp. 1 & 2, white, slight shine
EXPERIMENT 3 vol.2
3/4 of the mixture of Exp. 3
PREPARATIONS:
4. add 85ml of distilled water
5. boiled at 60 degrees Celcius
6. pour into large petri dish and large silver collection dish
7. distribute evenly with a spoon
____
OBSERVATIONS:
sticky consistency, porridge-like, ivory-coloured,
runnier than Exp. 3, firmer consistency than Exp. 2
____
EXPECTATIONS:
more pliable material than Exp. 3
EXPERIMENT 4
15g rice starch
5g xanthan
10g banana powder
7.5g glycerol
100ml distilled water
15ml vinegar
____
PREPARATIONS:
measure the distilled water, glycerol & vinegar, pour into a pot and stir together
slowly add the rice starch, xanthan & banana powder -> stir continuously with a whisk at 60 degrees Celsius
add another 5ml of distilled water, 5ml of glycerol & 5ml of vinegar
whisk for 2 minutes
pour into a petri and collection dish
evenly distribute the mixture with a spoon
____
OBSERVATIONS
lumpy & solid -> just as in Exp. 3, softer consistency/runnier, creamy with very small lumps
26.04.2024
CATCH UP
(12.04.) Experiment 1: (picture 1, left)
with lid - state: slightly firmer, like solid body cream, has a crack -> probably due to slowed drying out
without lid - state: same colour & mass, completely hard, no more soft spots
____
(12.04.) Experiment 2: (picture 1, right)
with lid - state unchanged
without lid - completely solid, can be bent -> breaks through
____
(19.04.) Mini - Experiment 1: (picture 2)
State - somewhat dissolved = piece is still intact, water has dried out
____
(19.04.) Mini experiment 2: (picture 3)
State - solid consistency, dissolved part sticks to the petri dish and is slimy/creamy
____
Result Mini - Experiment 1 & 2:
Experiment 1&2 absorb water, which dissolves the material and creates a slimy substance when it dries again
____
(19.04.) Experiment 3: (picture 4, bottom)
Petri dish - completely dried out, yellow/corn-coloured, large loss of mass (very flat layer)
Large silver collection dish - completely dried out, yellow „film“
____
(19.04) Experiment 3 vol.2: (picture 4 top, picture 5, picture 6)
Petri dish - completely dried out, too solid, breaks
____
(19.04.) Experiment 4: (picture 7, picture 8, picture 9)
Petri dish - soft, pliable, brownish yellow, air bubbles
Large silver collection dish - difficult to peel off (carefully!), flexible, only partially stretchable -> tears, beige transparent
PLAN
dry tangerine peel and bark in the oven (sterilising)
Experiment: Mixture without rice starch
EXPERIMENT 5
10g xanthan
10g banana powder
12.5g glycerol
105ml distilled water
20ml vinegar
(double the amount for preparation)
____
PREPARATIONS:
measure the distilled water, glycerol & vinegar, pour into a pot and stir together
slowly add the banana powder -> stir continuously with a whisk for two minutes at 60 degrees Celsius
slowly add the xanthan -> stir continuously with a whisk for two minutes at 60 degrees Celsius
whisk for 3 minutes without heat
pour into a large Petri dish
distribute evenly with a spoon
____
OBSERVATIONS:
milky consistency & colour when heated
Consistency - creamy/firm like jelly, beige grey colour when decanting
____
EXPECTATIONS:
material that does not break apart, dries, elastic, pliable
AUSBLICK
add the tangerine peel & bark (elm) to the mixture
sterilise in the oven for 90 minutes
03.05.2024
CATCH UP
(19.04.) Experiment 3:
State - unchanged, rock hard, corn coloured
____
(19.04.) Experiment 4:
State - flexible, elastic, does not break, smooth surface
____
(26.04.) Experiment 5: (picture 1)
State - not dried, same state as when poured, sticky, grey
PLAN
Repeat Experiment 4
Experiment 4 with bark (elm)
Experiment 4 with tangerine peel
EXPERIMENT 6
15g rice starch
5g xanthan
10g banana powder
12.5g glycerol
105ml distilled water
20ml vinegar
____
PREPARATIONS:
measure the distilled water, glycerol & vinegar, pour into a pot and stir together
slowly add rice starch, xanthan gum & banana powder -> stir continuously with a whisk at 60 degrees Celsius
pour into a petri dish (square)
on baking paper
EXPERIMENT 7
15g powdered bark (elm)
15g rice starch
5g xanthan
10g banana powder
12.5g glycerol
105ml distilled water
20ml vinegar
____
PREPARATIONS:
measure the distilled water, glycerol & vinegar, pour into a pot and stir together
slowly add rice starch, xanthan & banana powder -> stir continuously with a whisk at 60 degrees Celsius
add the bark and whisk
pour into a petri dish (square)
distribute the rest evenly on baking paper
EXPERIMENT 8
15g powdered tangerine peel
15g rice starch
5g xanthan
10g banana powder
12.5g glycerol
105ml distilled water
20ml vinegar
____
PREPARATIONS:
measure the distilled water, glycerol & vinegar, pour into a pot and stir together
slowly add rice starch, xanthan & banana powder -> stir continuously with a whisk at 60 degrees Celsius
add the tangerine zest and stir in
pour into a petri dish (square)
pour on baking paper
distribute evenly with a spoon
17.05.2024
CATCH UP
(26.04.) Experiment 5: (picture 1)
State - sticky, firm, pliable, sticks together (handle carefully!), slightly stretchy
____
(03.05.) Experiment 6:
State - pliable, elastic, does not break, smooth surface, good consistency
____
(03.05.) Experiment 7: (picture 2)
State - hard, not bendable, dark brown, breaks when bent
____
(03.05.) Experiment 8: (picture 3, picture 4)
State - pliable and firm, orange colour, good consistency
____
Result: Experiment 8 = final recipe
reason: pliable, soft, smooth underside, slightly rough upper side, robust, elastic, comes very close to leather properties
PLAN
Exp. 8: Quantity x3 to achieve a flat surface with a press
Exp. 4 with orange peel instead of tangerine peel
EXPERIMENT 9
26g powdered tangerine peel
45g rice starch
30g xanthan
30g banana powder
38g glycerol
300ml distilled water
60ml vinegar
____
PREPARATIONS:
measure the distilled water, glycerol & vinegar, pour into a pot and stir together
slowly add rice starch, xanthan & banana powder -> stir continuously with a whisk at 60 degrees Celsius
shred the tangerine peel
add the tangerine peel and stir in
pour into a petri dish (square)
on baking paper
fill into previously lasered medium-density fibre board (mdf) mould
distribute evenly with a spoon
put into the press
leave to dry
EXPERIMENT 10
12g powdered orange peel
15g rice starch
5g xanthan
10g banana powder
12.5g glycerol
105ml distilled water
20ml vinegar
____
PREPARATIONS:
slowly add rice starch, xanthan & banana powder -> stir continuously with a whisk at 60 degrees Celsius
add the orange peel and stir in
pour into a petri dish (square)
pour on baking paper
distribute evenly with a spoon
27.05.2024
CATCH UP
(17.05.) Experiment 9:
State - removed from the press: still moist, only slightly dried, left it outside the press, remaining in the mould for further drying
____
(17.05.) Experiment 10: (picture 1, picture 2)
State - well dried, elastic, pliable, firm, yellow
10.06.2024 - Open Lab Day
CATCH UP
(17.05.) Experiment 9:
State - well dried, left in the mould - baking paper removed to let it dry further, deep orange, smooth surface, pliable
____
Photos of the utensils and results
27.06.2024
CATCH UP
(17.05.) Experiment 9:
State - dried, deep orange, smooth surface, flexible, elastic, cut out from the mould
____
Photos of the result
FINAL RESULT
FLYER
UTENSILS
CONCLUSION
At the beginning, the production of the tangerine leather was a bit tricky. We did a lot of experiments to find out what quantities of the various ingredients would produce a satisfactory material of our intention. We were lucky that everything went smoothly and none of the experiments went mouldy. As a result, we were able to do even more experiments.
The tangerine peel gave the material a pleasant texture, firmness and colour. The banana powder, combined with rice starch, provided a certain elasticity that is very similar to that of leather. To summarise, the whole process was a great experience and we are proud of our result.
