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  1. Introduce at least 1 metal，1plastic ，1 composite materials in daily life ：
2. Introduce 2 new materials;
3. 1 methods post processing for 1 metal , 1 methods post processing for 1 plastic ,1 methods postprocessing for wood
4. Introduce detail all materails in our final project
1-1 metal--Titanium
1-2 plastic--Polyethylene
1-3 composite materials--Wood plastic composites
2-1 Milk Plastic
4-1 Acrylic (device housing)
4-2 Plastics（塑料）/plastics（塑胶）
---Miniature tree model & Miniatures of the house
4-3 Sandpaper--- miniature roads
4-4 PC pipe(Polycarbonate pipe)---Blowpipe
2-2 Aluminum Foam Sheet
3-1 Surface treatment process
3-2 Wood surface treatment process
Titanium, chemical symbol Ti, atomic number 22,
is recognized as a non-toxic element in the world.
This silvery-white transition metal, named after the
titan of Greek mythology, has many excellent
properties, including low density, high strength,
corrosion resistance, excellent high and low
temperature performance, non-magnetism, and
good biocompatibility.
Titanium's high specific strength properties are
particularly outstanding. High-strength titanium
alloys are as strong as high-strength steels, but their density is almost half that of them. This makes titanium a special material for NASA rockets and satellites, and is used in major projects such as China's Yutu, J-20, and Shandong aircraft carriers.
In the civil field, due to the natural bacteriostatic and biophilic properties of titanium, it has become the "honorary metal king" of the food industry. At the same time, because titanium is friendly to human tissues and does not cause an immune response in the human body, it is also widely used in the medical field.
Titanium and its compounds are widely used in many fields such as chemical industry, marine engineering, metallurgy, and medical treatment. Titanium is a strategic metal and an indispensable key material in the modern high-tech field, so it is also known as "space metal" and "marine metal".
a. Polyethylene
Chemical name: polyethylene
Polyethylene is a thermoplastic resin prepared by polymerization of ethylene, and also includes copolymers of ethylene and a small amount of olefins. Polyethylene is one of the five major synthetic resins, and it is the variety with the largest production capacity and the largest import volume of synthetic resins in China.

b .the performance of polyethylene :

1. General performance Polyethylene is a white waxy translucent material, odorless, tasteless, non-toxic, insoluble in general solvents at room temperature, and has low water absorption. PE is flammable, waxy when burned, and is accompanied by molten dripping.

2. Mechanical properties:
PE is a typically soft and tough polymer. Except for the high impact strength, the absolute value of other mechanical properties is low in plastic materials. With the increase of PE density, the mechanical properties except toughness are improved. The mechanical properties of several types of PE are shown in Table 1-1.
First, heat the milk to about 80 degrees
Vinegar is added to make the milk pH level acidic
Solid casein is separated from the liquid, which is mainly whey and water
Pinch them into the shape you want
After a few days of drying, a very hard substance is obtained
Dry the casein with a paper towel to allow it to be molded
a.Definition：
It is a new type of composite material that has flourished at home and abroad in recent years, which refers to the use of polyethylene, polypropylene and polyvinyl chloride instead of the usual resin adhesive, and then through extrusion, molding, injection molding and other plastic processing technologies to produce plates or profiles.

b.Scope of application:
One of the most important uses of wood-plastic composites is the application of replacing solid wood in various fields, among which the most widely used is in building products, accounting for 75% of the total number of wood-plastic composite products. Wood-plastic composites are mainly used in flower boxes, tree ponds, fences, garbage cans, stools, chair strips, signs, etc.

c.Key features:
1. Good processing performance;
2. Good strength performance;
3. It has water resistance, corrosion resistance, and long service life;
4. Excellent adjustable performance;
5. It has ultraviolet light stability and good colorability ;
6. It can turn waste into treasure and can be 100% recycled and reproduced. It can be decomposed, will not cause "white pollution", and is a real green and environmentally friendly product;
7. Wide range of raw materials;
8. It can be made into any shape and size according to needs;
a.What is Milk Plastic?
[ 牛奶能做塑料！科学家：能生物降解，未来能代替现有塑料吗？(baidu.com) ]
Milk plastic is a natural plastic alternative that uses discarded milk as the main ingredient. The plastic is made in a similar way to cheese, using waste milk combined with natural plasticizers to coagulate and dry into granular materials.

b.The process of making milk plastic:
用牛奶做塑料_哔哩哔哩_bilibili

c.What are the advantages of milk plastic?

1. Sustainability: Milk plastic uses waste milk as the main raw material to transform waste resources into useful products, helping to reduce the environmental impact of waste and reducing dependence on finite resources, making it more sustainable.
2. Lower carbon footprint: The process of making milk plastic reduces CO2 emissions compared to traditional plastic manufacturing processes.
3. Biodegradability: Milk plastic is more similar to natural materials in structure, so it can be more easily decomposed by microorganisms, reducing pollution to the environment. In contrast, traditional synthetic plastics typically take hundreds of years or more to degrade.
4. Diversity and plasticity: Milk plastic has similar properties to traditional plastics, and can be made into products of various shapes and uses through different processing methods, including containers, tableware, household items, etc. In addition, it can also be latheized and machined like wood, with a wider range of application prospects.
5. Reduced dependence on fossil fuels: Making milk plastic does not require the use of fossil fuels as a feedstock, so it can reduce dependence on finite fossil resources and reduce the damaging impact on the environment.

d.What can milk plastic be used for?

1. Packaging industry: food packaging boxes, containers, bottles, cosmetics packaging boxes, bottles, daily necessities packaging boxes, bottles, etc.
2. Food service industry: disposable tableware, such as knives, forks, spoons, chopsticks, etc. Reusable utensils such as plates, bowls, cups, etc.
3. Household items: storage boxes, baskets, flower pots, etc. Furniture components, such as chairs, table components.
4. Stationery: pens, pencil cases, folders, etc.
5. Industrial products: industrial containers, storage barrels, etc.
6. Arts and crafts: sculptures, ornaments, etc.

e.The process of making milk plastic
a.What is Aluminum Foam Sheet? 
Aluminum foam plate is made of pure aluminum or aluminum alloy after adding additives, through the foaming process, which has both metal and bubble characteristics, and the surface of the aluminum plate has a dense porous metal structure, which is the largest morphological feature of this material. Aluminum foam board provides more choices for architects due to its stable quality, unique appearance, strong functionality, and wide variety of specifications, and is often used in a large area in the interior and exterior walls of buildings, indoor floors and other scenes, and the material is easy to process and install.

b.What are the performance characteristics of aluminum foam sheet?

1: Noise reduction and sound insulation
Because of the special structure formed in the production process, the foam aluminum sheet has good sound absorption performance, even in the humid environment of the bathroom and toilet, the material still maintains a good sound absorption and noise reduction effect, which is more than double the noise reduction effect of other sound absorption materials.

2: Fire and heat insulation
Aluminum metal has good flame retardant and heat resistance, and a large area of foam aluminum panels are laid on indoor and outdoor walls, columns and other blocks, which is equivalent to forming an efficient fire zone in the space, especially in large private houses, exhibition halls and other buildings, which can effectively improve the indoor and outdoor fire coefficient.

3: Durable and corrosion-resistant
The surface of the foam aluminum board has good antioxidant properties, such as in the bathroom, it is not easy to be eroded by moisture, not easy to mold, not easy to dirty, and it is used indoors, does not change color, and can be cleaned in outdoor rainy areas.

4: Good light transmittance
The multi-angle refraction of light from the various holes generated by gas foaming in the double-sided perforated translucent plate can produce rich and brilliant brilliance when doing light transmission applications.

5: Good decoration
The surface of the foam aluminum plate can be sprayed with different colors or patterns for decoration, and the coating has been sprayed and dried for many times to form a beautiful decorative effect, which can meet the creative and artistic treatment of the designer during the decoration design.

6: Recyclable
The foam aluminum plate is made of aluminum alloy die-casting, and after breaking, it can be fully recycled, which is a new type of green and environmentally friendly high-tech product that does not cause secondary pollution to the environment.

7.Fire performance
The porous structure of aluminum foam forms a large number of closed pores, which have good thermal insulation properties and can effectively isolate high or low temperatures. Therefore, aluminum foam is widely used in the field of thermal insulation materials, such as construction, refrigerator manufacturing, etc. At the same time, aluminum foam has good fire performance, is not easy to burn, and can effectively slow down the spread of fire.
a.[Sanding]:
The process of grinding back and forth in the direction of the wood grain is carried out on the surface of the wood with sandpaper to make the wood surface smoother.
There are mechanical sanding and manual sanding
a.Sandpaper definition:
It is a kind of paper with abrasive particles attached to it, which is used to level the surface of an article, or remove the attachment on the surface; Sandpaper is divided into different specifications according to different roughnesses to match different uses.

b.Type:
Sponge sandpaper: suitable for sanding smooth parts, all kinds of materials are acceptable; Dry sandpaper: a variety of fineness options are available, suitable for sanding materials such as wood or metal; Wet sandpaper: fine texture, suitable for polishing delicate materials, with water.

c.Sandpaper unit:
Purpose: defined as the number of abrasive particles per square inch of area, the higher the value, the more particles and the finer the abrasive; Woodworking grinding follows the principle of coarse to fine, that is, from low mesh sandpaper grinding to high mesh sandpaper;
Commonly used mesh: 80, 100, 120, 150, 180, 220, 280, 320, 400, 600;
Fine grinding: 800, 1000, 1200, 1500, 2000, 2500, 3000, 5000;
（Comparative analysis with PVC pipes）
1. The ingredients are different
● PC Pipe: The main ingredient is polycarbonate resin (a polymer containing a carbonate base in the molecular chain)
● PVC Pipe: The main ingredient is polyvinyl chloride resin (a thermoplastic polymer made from the polymerization of vinyl chloride monomer (VCM)).
2. the appearance is different
● PC Pipe: The PC tube has good light transmittance and good transparency, which is suitable for scenarios where the fluid state needs to be observed. (However, when the PC tube is used as a threading tube, it is generally made opaque and milky white due to performance considerations.)
● PVC Pipe: PVC pipes are generally opaque or translucent, with poor light transmittance, and the inside of the pipe cannot be directly observed.
3.the impact resistance is different
● PC tube: It has excellent impact resistance and is a high-toughness material that retains good impact resistance even under extreme temperature conditions.
● PVC Pipe: The impact resistance is poor, and it is easy to crack or break when impacted, especially in low temperature environments.
4.the bending strength is different
● PC tube: It has good bending strength and can withstand a certain degree of bending and deformation without breaking.
● PVC Pipe: The bending strength is relatively low, and it is easy to deform and crack when subjected to external forces;
5. The applicable temperature range is different
● PC tube: It has a wide temperature range and is generally able to operate normally from -40°C to -130°C. (Generally starts to soften at around 140°C)
● PVC Pipe: It is generally suitable for temperatures ranging from 0°C to 60°C.
6. the weather resistance is different
● PC tube: It has good UV resistance, is not easy to age and become brittle under sun exposure, and is suitable for long-term outdoor use.
● PVC Pipe: It is less resistant to ultraviolet rays and can age, become brittle, and discolored when exposed to sunlight for a long time.
7. Different application fields
● PC tube: It is often used to protect pipes with wires and cables in high-strength, impact-resistant environments, and is widely used in lighting, medical, electronics, and other fields due to its highly transparent properties. ● PVC Pipe: It is mainly used for drainage, sewage and farmland irrigation, wire and cable protection in residential, commercial buildings and industrial facilities.
8. The cost is different
● PC tube: Polycarbonate resin is a high-performance plastic, the market price is high, and the production process is relatively complex, so the cost is high.
● PVC Pipe: Polyvinyl chloride resin is a common plastic raw material, the price is relatively stable, and the production process is relatively simple, so the cost is low. The above nine points are the overall comparison of PC pipe (polycarbonate pipe) and PVC pipe (hard PVC pipe), in addition, for the flame retardant performance of the two, I personally feel that the flame retardant is quite strong, and it can be extinguished from the fire, so the flame retardant performance is not listed separately for comparison.
（Plastics (塑料） we mentioned above）

a. Products that can be made of plastic（塑胶）
1. Toys: Plastic toy vehicles, toy animals, toy figures, etc. are all common plastic products.
2. Household items: such as plastic cutlery (bowls, plates, cups), plastic storage boxes, plastic vases, etc.
3. Electronic devices: The parts of many electronic devices are made of plastic, such as mobile phone cases, keyboards, headphones, etc.
4. Sports products: such as plastic treadmills, plastic basketball courts, plastic fitness paths, etc.
5. Packaging materials: Many goods use plastic packaging during transportation and storage in order to maintain their freshness and aesthetics.

b. the classification of plastics （塑胶）
1. Polypropylene (PP): This material is commonly used to make buckets, food containers, pipes, etc. Because it has high heat and cold resistance, it is ideal for making food-related containers. For example, the yogurt cups and beverage bottles we commonly use are made of polypropylene.
2. Polyethylene (PE): This material is widely used to make films, pipes, bags, etc. Because it has good corrosion resistance, it is often used as a packaging material. For example, the plastic bags we use when shopping are made of polyethylene.
3. Polystyrene (PS): This material is commonly used to make bowls, plates, and cups, among other things. Because it has a good hardness and gloss, it is often used to make beautiful tableware.
4. Polyvinyl chloride (PVC) :P VC is a relatively common plastic material, which is often used to make water pipes, door and window guards, children's toys, etc. It is also widely used in the manufacture of some insulated electrical components.
5. Polycarbonate (PC): This material is often used to make some of the more advanced containers, such as computer cases and coffee makers. It has great durability and impact resistance, and is able to withstand drastic changes in temperature.
6. Polyoxymethylene (POM): This material is often used to make some parts with special properties, such as high-efficiency bearings and gears. It has high hardness and good wear resistance.
a.Conceptual definition
Acrylic, also known as plexiglass, is a polymer material with good plasticity, although the appearance is as bright and transparent as glass, but the performance is not as fragile as glass.
On the contrary, acrylic is durable, easy to process, and not fragile , and can be integrated into a variety of colors to release the visual effect of Ambilight, and can also be made into decorations and furniture with different shapes according to different needs.
In addition, it also has a certain flame resistance and stability , the material is lightweight, the density is half of that of glass, when used in the home, it can give the space a certain sense of lightness and agility, and it will not be heavy when used.

b.Reasons for favoring 
1.Wide range of applications.
Due to the superior performance of acrylic itself, in addition to being used as a variety of interior decoration, it can also be used to create a partial appearance of buildings, or used to make doors and windows on vehicles.
2.Beautiful and stylish
For different home styles, acrylic furniture or decorations can find their own home and blend in well.
And the texture of its material is as rich and varied as it is presented itself, with mirror panels, pearlescent plates, frosted boards and other options, and the spatial effects presented by each texture also have their own merits.
In the process of integrating into the space, choosing a random texture of furniture or decorations is enough to create a focal point for the space and make the whole space look beautiful and stylish.

c.Acrylic sheets can be divided into according to light transmittance . 1.Transparent plates,
2.Translucent plates (including stained plates, transparent plates),
3.Color plates (including black and white and color plates)

d.Acrylic sheets can be divided into according to their performance
Impact resistant plates, UV resistant plates, ordinary plates and special plates such as high impact plates, flame retardant plates, frosted plates, metal effect plates, high wear resistant plates, light guide plates, etc.

e.Processing technology of acrylic sheet
(1) Casting molding:
Casting molding is used to form plexiglass plates, rods and other profiles, that is, to form profiles by bulk polymerization method.
(2) Injection molding:
Injection molding uses pellets obtained by suspension polymerization, which are molded on ordinary plunger or screw injection molding machines.
(3) Extrusion:
Polymethyl methacrylate can also be extruded to prepare plexiglass plates, rods, pipes, sheets, etc. with pellets produced by suspension polymerization, which has the advantage of high production efficiency, especially for pipes and other profiles that are difficult to manufacture with molds when pouring method.
(4) Thermoforming:
Thermoforming is the process of making plexiglass sheets or sheets into products of various sizes and shapes, clamping the blanks cut into the required size on the mold frame, heating to soften them, and then pressurizing them to make them stick to the mold profile to obtain the same shape as the profile, and trimming the edge after cooling and shaping to obtain the product.
(5) Engraving and cutting:
It is mainly for the hollowing and engraving of acrylic or colored acrylic materials that have been formed. Ordinary laser engraving and cutting machines can meet the engraving and hollowing needs of most acrylic products


Electrophoresis(EP）:
Introduce:[ 电泳_百度百科 (baidu.com) ]
Introductory video:[ http://baike.baidu.com/l/KQcb6K5g ]

Electrophoresis (EP) is an abbreviation for electrophoresis phenomenon, which refers to the phenomenon in which charged particles move towards electrodes opposite to their electrical properties under the action of an electric field. The technique of separating charged particles by moving at different speeds in an electric field is called electrophoresis.
Effect of electrophoretic dissociation technique before and after protein removal
The general process flow of anodic electrophoresis is as follows:
workpiece pretreatment (degreasing→ hot water washing→ rust removal→ cold water washing→ phosphating→ hot water washing →passivation) → anode electrophoresis → post-treatment of the workpiece (washing with water → drying).

1. Degreasing. The solution is generally a hot alkaline chemical degreasing solution, the temperature is 60 °C (steam heating), and the time is about 20min.
2. Wash with hot water. The temperature is 60 °C (steam heating), and the time is 2min.
3. Rust removal. With H2SO4 or HCl, e.g. with hydrochloric acid rust remover, HCl total acidity ≥ 43 points; Free acidity> 41 points; Add 1.5% cleaning agent; Wash at room temperature for 10~20min.
4. Wash in cold water. Wash with cold water in running water for 1min.
5. Phosphating. Phosphate at medium temperature (phosphating at 60 °C for 10min), and the phosphate solution can be used as a commercially available product. The above process can also be replaced by sandblasting → washing. 6. Passivation. With the drug matched with the phosphate solution (provided by the manufacturer selling the phosphate solution), 1~2min at room temperature.
7. Anode electrophoresis. Electrolyte composition: H08-1 black electrophoretic paint, solid content 9%~12%, distilled water mass fraction 88%~91%. Voltage: (70±10)V; Time: 2~2.5min, Paint temperature: 15~35°C, Paint pH: 8~8.5. Note that the workpiece in and out of the groove should be powered off. During electrophoresis, the current gradually decreases as the paint film thickens.
8. Wash with water. Wash under cold running water.
9. Drying. It can be baked in the oven at a temperature of (165±5) °C for 40~60min.
An example of a surface treatment process: Anodizing, Electrophoresis, Microarc oxidation,Physical vapor deposition, Electroplate, Powder coating, Metal brushing, Sandblasting, Polished, Etching
A brief introductory video： http://baike.baidu.com/l/lVFiRlkp
b.[Polished]:
Remove the surface of the wood products stained by glue marks, oil stains and other dirt, first polish them with sandpaper, and then scrub them with cotton yarn dipped in gasoline. If the cleaning is not clean, use a fine planer to clean the surface.
c.[Decolorization]:
The wood is bleached with oxidation-reduction chemicals.
Commonly used decolorizing agents: hydrogen peroxide, sodium hypochlorite, sodium peroxide
d.[Stain]:Chemically or otherwise influencing the substance itself to color it, so that the object takes on the colors that people need.
There are two types: water dyeing and wine dyeing.