Background

 In Germany's countryside and forested areas, fallen leaves are generally not treated in any special way. The reason is that in the case of natural degradation, fallen leaves contribute to humus buildup, which is good for the natural environment. People can use them for composting.

In the case of towns and cities, the area of hardened pavement is much larger than in the countryside. The massive accumulation of fallen leaves each autumn can cause a number of problems for towns. First of all, the accumulation of fallen leaves on roads may cause them to be very slippery, especially in rainy weather. In addition large amounts of fallen leaves may cover roadway obstructions. Every year there are news stories of people tripping and falling because they can't see the road surface. Secondly, fallen leaves may clog drainage systems such as storm drains, sewers and outfalls. This can result in rainwater not draining quickly, increasing the risk of flooding, especially during heavy rainfall seasons. Third, dry fall leaves are flammable. If they accumulate during the dry season, they can become fuel for urban fires. Fourth, in some cases, fallen leaves can also enter a building's plumbing system, leading to clogs and repair needs. In addition, the accumulation of large amounts of fallen leaves in the natural environment may have a negative impact on soil and water quality. Decomposition of leaves may lead to organic matter and nutrients entering water bodies, causing water quality problems.

That's why leaves in cities need to be disposed

of. According to statistics, as many as 10,000

tons of fallen leaves are cleared away each year in Germany's 10 most densely populated cities. [1] According to the data released by the German Federal Environment Agency, in some of Germany's largest cities and regions, the government needs

to spend millions to tens of millions of euros, or even more, every year to deal with the fall leaves. It is also because of the high cost and difficulty of disposal. Therefore, the government has started to take measures to reduce these costs, such as encouraging residents to engage in autonomous leaf composting, thus reducing the need for transportation and disposal.

The Goal

As the quest for sustainable design continues to heat up, the main goal of this project is to explore and innovate bio-based materials using fallen leaves as a base material. I will conduct a more detailed study of maple leaf litter (This project is centered around the fallen leaves of a maple tree.) to understand

its chemical composition, fiber structure, processability, and other properties.

Using the information obtained from the

study, I will conduct a large number of material experiments. During the process, I will focus

on the physical properties, processability, and degradability, in order to lay the groundwork for the final material to be used in green planting pots and products.

Through this project, I adhere to the goals of sustainable development, eco-friendly design and resource recycling to provide an innovative and eco-friendly solution for modern green planting.

Design concept:

From the beginning to the end of the trip is a circle. Natural materials are made into products and finally degraded. The whole process reduces the carbon footprint and finish a circular design.

Design Point:

Natural

Eco-friendly

100% Biodegradable

Recycled Design

Modular Design

Lightweight

Easy to produce

Cheap

Unique

Before Experiments

Before starting the formal material experiments, the fallen leaves as the base material needed to be treated in advance. In order for the leaf material to better integrate with other materials and produce diverse physical and chemical changes, I treated the leaves as follows.

I removed the leaf stalks from the collected leaves. This is to give the material a more even texture. Next I cut the leaves into as small pieces as possible and wash them. Pour enough water in a pot and add baking soda, pour the leaves into it and cook for 60-90 minutes. The baking soda will soften the leaves better. Pour the cooked leaves into a blender and puree. At this point the leaf pulp contains too much water, so I need to use a strainer to get rid of the excess water. This completes the initial processing of the leaf material.

Experimental materials:

- Fallen leaves(collected on campus)

- Starch, Sticky rice, Gelatine, Agar, Xanthan Gum, Guar gum, Carrageenan, Okra, sugar, glycerin, vinegar, coconut oil(all purchased at Supermarkets or Amazon)

Experimental materials:

small cooking pot, electric stove, stirring rod, blender, food scale, measuring cup, strainer, mold frame...

ps: Starch, Sticky rice, Gelatine, Agar, Xanthan Gum, Guar Gum, Carrageenan involved in the experiment refer to the weight of their solutions. The proportion of each solution will be stated in the specific experimental results report.

Experiments -Phase 1-

The aim of this project is to conduct an in-depth comparative study by combining leaf litter materials with a variety of other materials. Focus on the changes in the properties of each material after drying. Compare and contrast the surface characteristics, stability, strength and other key features of the different materials.

The focus of this experiment is to use the fiber structure of the fallen leaves to help the material have more hardness. However, the fallen leaf material itself cannot be molded on its own without the help of an adhesive. So I tried starch, agar, gelatine and other adhesives. At the same time I also tried edible glues as well as plants with their own slime. I combined the processed leaf material with different adhesives and added other auxiliary materials to give the new material more textural possibilities.

An overview of the experiment is shown below.

Based on my observations of the material pieces after the experiment, conclusions can be drawn.

The materials with the addition of starch show characteristics. They all have a certain degree of softness and are better to the touch with a smoother surface. However, they are not strong and break easily.  The addition of sticky rice flour allows the material to show similar characteristics to the starch group. The difference, however, is that the sticky rice flour makes the material stronger. But this kind of sturdiness was only relative. It does not achieve the desired strength. Xanthan gum and Guar gum can not bring materials to the desired state either. They both have very weak connecting structures. The materials are all very soft. But the use of carrageenan produced a falling leaf material with a more suitable hardness, which is worth optimizing and delving into. Then I tried using the natural okra slime as a binder again. But it didn't work well. Each piece of material was soft and easily damaged. The materials of the agar group show a uniform characteristic, that is, the materials are very easy to shrink and deform during the drying process. In other words, it is not easy to control the molding process. After complete drying the material becomes hard and has no elasticity at all. Gelatine group is similar to agar group. But the material in gelatine group are softer. The pieces in agar group are more fragile and easier to break. The material in gelatine group have more toughness than in agar group.

The texture of the material pieces varies greatly, and it is possible to compare them by touching them with the hand. Considering that the materials will eventually be used in planters, I compared and ranked the available material pieces in terms of hardness and toughness(Here we are talking about the tensile strength of the material).

As you can see, the closer to the upper right corner of the material pieces, the more meet the requirements. The pieces with oil on their surfaces, which are prone to deformation during drying or which break on their own, are removed. Finally 10 material pieces were selected for the next experiments. I will use them as a basis for optimization.

Experiments -Phase 2-

Next I made larger material pieces of the selected 10 materials to get better test results. I considered the actual size of the flowerpot product design and made material frames with a size of 15*15cm and a thickness of 3mm. This will better keep all the material pieces at a uniform size.

As you can see in the experiment report, the same material ratios will have different textures at different sizes. That is, a small piece of material may not perform as well when made into a large piece. This is why it is important to simulate as much as possible the size of the material required for the final production. At the same time, I iterated on these 10 pieces to optimize the material. In the end, I compared these 10 pieces with their optimized pieces.

Through this stage of experimentation I realized that some materials may be fine when they are made into small pieces. But when being made into large pieces they will break like piece 5B and piece 20. Piece42, piece 42A and piece 42C, these pieces of material with carrageenan as the binder are also easy to break during the drying process. They do not have good structural strength. Such material pieces which break easily cannot be applied to the product. Secondly some materials are particularly easy to deform during drying, like piece 5C1, piece 5C2 and piece5C3. Therefore it is important to make larger pieces of material for testing.

But at the same time, some of the material pieces have great texture. From piece 24 to piece 25B, which are made of gelatine, all show better texture. Of course there will be differences between them. Each material piece has its own characteristics. At this time, these material pieces are able to meet the requirements of making products.

Based on the size of the real product sized models I made, I chose the two models with the smallest and largest loads to measure. I measured their weight after they were loaded with soil. From this, I learned that they can load 250g and 650g of soil respectively. Therefore I placed each piece of material in the experiment under these two weights to see if they could carry such weights or if they deformed.

The test results show that there was more than one piece of material that met the requirements in the second phase of the experiment.

From these pressure-resistant pieces of material I ended up with the piece24. This is because its test results not only meet the requirements, but also present a more stable state during production and drying.

Produce

In this project, I pursue not only innovation, but also a deep understanding and practice of sustainability. Using fallen leaves as the base material for experimental research, I have applied bio-based materials, with fallen leaves as the main material, to the manufacture of flower pot products. This design concept unites the ideas and principles of several aspects, aiming to promote the realization of green design and circular economy.

First of all, my materials are applied to temporary flower pots, pots used to plant plants with a short flowering period, and nursery pots. These flower pots are characterized by a short service life and are consumables. Through the previous research, we can see that this type of flower pots on the market are basically plastic-based, and plastic that needs to be degraded for hundreds of years is obviously not in line with the requirements of environmental protection. Therefore, by replacing traditional plastic materials with new bio-based materials, I call on designers to reduce their dependence on non-renewable resources such as oil and promote the concept of sustainable development. The manufacture of flowerpot products is no longer a burden on the environment, but a way to give back to nature.

Secondly, circular design is not only a goal, it is my design principle. I integrate circular design into the whole project, from production, use to disposal, considering the impact of the product throughout its life cycle. By choosing biodegradable materials, modularizing the product and other means. I encourage users to participate in diy activities for their own products and indirectly participate in feeling recycled and reused. This minimizes the impact on the environment and truly realizes the concept of recycling.

Because of the characteristics of the material and the difficulty of drying during processing, I chose to use modular means as much as possible to create the final flower pots. I use a modular approach to assembling the flower pots. This reduces transportation costs, increases size flexibility, reduces waste disposal, and increases user interest.

 I also used the original colors of the materials in their most natural form. The purpose is to convey a more natural and relaxed feeling.

Final Product