Question 2: Who knows what material the shoe last is? Is it poisonous? Last is a kind of plastic, which is divided into white material, second material and worse material, all of which are non-toxic.
Question 3: What kind of plastic polyethylene is the last head made of? It is a mixture of high-pressure and low-pressure materials. However, the materials made now are mainly recycled materials, not pure granular materials, and the cost is unbearable.
Question 4: Excuse me, friend: What is the plastic shoe last made of? Thank you for your 45-minute paper translation-mechanical data translation-mechanical and electrical products translation-engineering tender translation.
Zhuo Ma document translation, Zhuo Ma mechanical data translation-Zhuo Ma mechanical and electrical products translation-Zhuo Ma engineering tender translation.
Translation of electric power tender-engineering tender-railway construction tender
Zhuo Ma electric power tender translation-Zhuo Ma engineering tender translation-Zhuo Ma railway construction tender translation.
Translation of bidding documents for water conservancy projects-Translation of bidding documents for petroleum projects-Patent translation major
Zhuomate bidding document translation of water conservancy project and Zhuomate bidding document translation of petroleum project-Zhuomate patent translation major
Patent translation company-invention patent translation-utility model patent translation
Transit patent translation company-Transit invention patent translation-Transit utility model patent translation
Clinical technical data translation, technical literature translation, bidding translation/technical literature translation.
Zhuo Ma clinical technical data translation, Zhuo Ma technical literature translation, Zhuo Ma tender translation, Zhuo Ma technical literature translation.
IT data translation/explanation translation English translation data
TransIT it data translation, transit instruction translation, transit English translation data.
Question 5: What is a shoe last? What kinds of shoe last are there? Finally, the matrix of shoes. This is the mold for shoes. Last not only determines the shape and style of shoes, but also determines whether the shoes fit and protect the feet. Therefore, the design of shoe last must be based on the foot type, but it can't be exactly the same as the foot type, because the shape, size and stress of the foot change when it is at rest and moving, and the variety, style, processing technology, performance of raw and auxiliary materials, wearing environment and conditions of the shoe last are also different, so the shape and size of each part of the shoe last can't be exactly the same as the foot type. Therefore, modern shoe last design not only involves many disciplines, but also requires very high manual skills and experience. But shoe last appeared in ancient times. In 1 century BC, the murals of Heck Rannem (an ancient city in southwest Italy) showed the image of a shoemaker pulling a shoe last out of his shoe, while in China, two wooden shoe last objects were unearthed at the Niya site of the ancient Silk Road in Xinjiang in 196 1 year. The male shoe last is 24cm long and 8cm wide. 5 cm, 8 cm thick, another female last, 2 1? 5 cm, 7 cm wide and 6 cm thick, it is a work of Tang Dynasty 1400 years ago.
Question 6: What is the plastic bottle made of? Beverage bottles (such as Coca-Cola's) are mostly plastic products, mainly made of polyethylene or polypropylene, and various organic solvents are added. Polyethylene and polypropylene are nontoxic and tasteless, so it is safe for people to fill drinks. However, once polyethylene is corroded by high temperature or acid, it will slowly dissolve and release organic solvents, which is harmful to human body.
It has been reported that long-term consumption of food contaminated by polyethylene molecules will cause dizziness, headache, nausea, loss of appetite, memory loss and even anemia. Therefore, using vinegar in plastic bottles is harmful to human health. Therefore, glassware should be used instead of plastic products to hold spices and the like in the family. When using plastic products, we should pay special attention to avoid contact with vinegar, detergent, etc. And avoid direct sunlight and high temperature to avoid chemical reaction. In addition, when buying plastic tableware, you should choose plastic products with PE (polyethylene) or PP (polypropylene) labels, few decorative patterns, colorless and tasteless, and smooth surfaces.
There are many ways to make polyethylene, and the most common one is to polymerize ethylene at 200 ~ 300℃ and 1000 ~ 2000 atmospheric pressure. In polyethylene, no other substances are doped. The polyethylene prepared by this method has low density, soft texture and high stability to sunlight, air, moisture and chemical reagents, so there is no need to add stabilizers and plasticizers, which are mostly toxic or highly toxic.
About recycling:
``````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````````
Your current position: China Plastics Industry Network >> Special Topics on Waste Plastics >> Knowledge of Recycling Plastics >> Recycling >> The date of this article is July 29th, 2008.
Tuesday
This paper introduces the concrete method of producing shoe last with recycled polyethylene plastic.
hot
This paper introduces the special arc method of producing shoe last with recycled polyethylene plastic.
Author: anonymous article source: unknown hits: 1263
Polyethylene (PE) can be described as high pressure polyethylene (LDPE) and low pressure polyethylene (HDPE), and some of them are mixed. The raw material of polyethylene is milky white, non-toxic, tasteless and waxy particles with shiny surface. Commonly used in packaging films, agricultural films, injection molded products, cable sheaths, blow molded products, packaging boxes, turnover boxes, etc. A polymer of ethylene and propylene, often used in food packaging or turnover boxes. Polymers of ethylene and butene are commonly used in the above raw materials, including degradable or non-degradable polyethylene, high-pressure polyethylene and compressed polyethylene. All colors can be mixed and used without decoloration. Firstly, the recycled waste polyethylene was cleaned, degreased and dried. If possible, it can be granulated by a granulator, otherwise it will be crushed or cut into pieces, and then added to the hopper of the injection molding machine. The temperature of injection molding machine should be: feeding section 150℃, middle section 170℃, and head 200℃. After heating, the polyethylene can be freely poured into the shoe last mold by the machine head, filled and put into water at 20-50℃ for cooling and setting for 2 hours. After cooling, it is demoulded into a plastic shoe last blank, and the blank is processed by imitating tin to obtain the finished shoe last.
Finally, the mold in shoemaking production. The color and composition of recycled polyethylene will not affect the quality of finished shoes. The recycled waste polyethylene can be used directly without adding any auxiliary materials. The cost of producing shoe last from waste polyethylene is the sum of the expenses of recycling polyethylene waste, cleaning, granulating, injecting last blank, tin last shape and other related expenses. The weight of each pair of shoe last is about 1.5-2kg, and the price of the finished shoe upper for men and women is 17- 19 yuan, which makes a considerable profit. There are 3,665 shoe-making industries in China, and the last weighs about 5 million pairs every year. The development prospect is very optimistic.
Using waste polyethylene to produce shoe last can replace wood last and reduce deforestation resources. Plastic shoe last can be recycled at a discount after use, and can be processed into a new shoe last for recycling after crushing, thus realizing the resource recycling of white pollution. Waste polyethylene can also be used to produce industrial material turnover boxes, packaging materials, agricultural fruit and vegetable turnover boxes and other products, which need further development and utilization.
The above information is for reference only, and offenders may not reprint it. This station reserves all rights.
``````````````````````````````````````````````````````````````
Literature/invention patent on polyethylene recovery/recycling and utilization ................................................................................................................................................................ >
Question 7: How long does it take to produce a pair of shoe last? This is related to the shape and material of your last:
The main material of shoe last is HDPE plastic.
It takes 1 to 3 days to develop a female last, and then produce it with the female last. Finally, it takes about 15 minutes to scan a woman, and then it is made with scanned 3D drawings. Roughing takes about 1 min, and finishing takes about 1 min.
Post-processing depends on the shape, the fastest time is 1 hour, and the slow time is two hours. Of course, it refers to the shoe last with ordinary shape.
The output of aluminum last may be 20 times that of plastic last.
Question 8: What is the last head? It should be a tool for making shoes, that is, after making new shoes as a child, you should plug them with the last head.
Then after a day or two, the new shoes are not all curved, and they don't rub their feet.
Question 9: What are shoe accessories? They refer to materials that play an auxiliary role in the use of shoe materials, such as connection, decoration and function. Accessories of shoe materials include wires, glue, shoe buckles, shoe last, plastic drops, hardware, etc. Shoes usually consist of soles and uppers. The sole is made of rubber, plastic, genuine leather, elastic cardboard, etc. The materials used in the vamp are natural leather, artificial leather, canvas, mesh cloth, etc. The materials used in soles and uppers are main materials, and these main materials need the cooperation of auxiliary materials to make shoes.
Question 10: What can be done to solve the problem that the hardness of the finished shoe last cannot reach? First of all, what material is your last?
At present, the most common material on the market is HDPE plastic.
If the hardness is not enough, it is necessary to use brand-new materials for injection molding. The hardness of the new material will reach 60-65 Shore, and glass fiber can be added to improve the hardness, but the last will become brittle and the impact resistance will become worse.
In addition, there are also aluminum last, but not many, because the processing is difficult, so the price is expensive.
The hardness of aluminum shoe last basically reached the shoemaking process. If your technology is special and the aluminum shoe last is not hard enough, then the steel shoe last must be hard enough, but the cheap one costs several thousand yuan a pair.