What are plastic products?

Gourmet plastic products are a general term for daily necessities and industrial products that are made of plastic as the main raw material. They are made of synthetic polymer materials with plasticity. Plastics, synthetic rubber, and synthetic fibers form the three major synthetic materials that are indispensable in daily life. Plastic products have penetrated into every aspect of people's lives and are increasingly changing people's lives. In this issue, the editor of 51Dongshi.com will explain the relevant knowledge of plastic products in detail. How to classify plastic products 1. Thermosetting plastics

The characteristic of this type of plastic is that it solidifies at a certain temperature and after heating for a certain period of time or adding a curing agent. The cured plastic is hard and insoluble in any solvent, and it cannot be softened again by heating. It will decompose if the heating temperature is too high. Common thermosetting plastics include bakelite, electric jade, decorative boards and unsaturated polyester plastics.

2. Thermoplastics

The characteristics of this type of plastic are that they soften when heated and harden when cooled. During processing, they generally only undergo physical changes while maintaining their chemical nature. The resins of this type of plastic are mostly made by addition polymerization. Common thermoplastics include: nitrocellulose plastic, cellulose acetate plastic, polyethylene plastic, polypropylene plastic, polystyrene plastic, polyvinyl chloride plastic, etc. For example, our common mineral water bottles, plastic bags, etc. Details >>

The meaning of plastic product logos and symbols China has formulated the GB/T16288-2008 plastic product logo with reference to the material variety marking proposed and implemented by the American Plastics Institute (SPE). The bottom of each plastic container All have a numerical designation that represents the plastic used in their manufacture. Therefore, common plastic products in the current market are generally divided into numbers 1-7. In our country, it is not compulsory to mark plastic products with recycling signs. In order to facilitate the recycling of plastic products, some large and formal companies have recently begun to mark recycling signs.

The plastic product mark is generally a triangular mark with an arrow, with numbers from 1 to 7 marked inside. First of all, the "triangle" is a plastic recycling symbol. Currently, our country uses the triangle symbol as the plastic recycling symbol. Secondly, there are numbers 1-7 inside the triangle, and each number represents a different material. The applicable scope and usage requirements of each plastic are very different. If it is smaller than "05", that is, "04" and below, there is even no number. Please do not reuse or heat it because it will release harmful chemicals. Substances that cause cancer. Details>>

Safety grade "No. 1" PET polyester for plastic products

Application scope: common mineral water bottles, pure water buckets, carbonated drink bottles, etc., heat resistant to 65°C, It is cold-resistant to -20℃ and is only suitable for warm or frozen drinks.

"No. 2" HDPE high-density polyethylene

Applicable scope: common white medicine bottles, cleaning supplies, bath products, etc.

"No. 3" PVC polyvinyl chloride

Application scope: common raincoats, building materials, plastic films, plastic boxes, etc. This material has excellent plasticity and is cheap, so it is widely used .

"No. 4" LDPE low-density polyethylene

Scope of application: generally PE polyethylene, common cling film, plastic film, etc.

"No. 5" PP polypropylene

Application scope: common soy milk bottles, yogurt bottles, juice drink bottles, microwave lunch boxes.

"No. 6" PS polystyrene

Application scope: common bowl-type instant noodle boxes, fast food boxes, etc.

"No. 7" PC other plastics

Applicable scope: common kettles, water cups, and baby bottles. Department stores often use water cups made of this material as gifts. Details>>

Advantages and disadvantages of plastic products 1. Light weight

Plastic is a lighter material with a relative density distribution between 0.90-2.2. Obviously, can plastic float to the surface? In particular, foamed plastics have micropores and are lighter in texture, with a relative density of only 0.01. This property allows plastics to be used in the production of products that require weight reduction.

2. Excellent chemical stability

Most plastics have good corrosion resistance to chemicals such as acids and alkalis. Especially polytetrafluoroethylene (F4), commonly known as the king of plastics, its chemical stability is even better than gold, and it will not deteriorate even if it is boiled in "Aqua Regia" for more than ten hours.

Because F4 has excellent chemical stability, it is an ideal corrosion-resistant material.

3. Excellent electrical insulation properties

Ordinary plastics are poor conductors of electricity, and their surface resistance and volume resistance are very large, which can reach 109-1018 ohms in numerical terms. The breakdown voltage is large and the dielectric loss tangent is very small. Therefore, plastics are widely used in the electronics and machinery industries. Such as plastic insulated control cables.

4. It is a poor conductor of heat and has the functions of silencing and shock absorption

Generally speaking, the thermal conductivity of plastic is relatively low, equivalent to 1/75-1 of steel. /225, the micropores of foam plastic contain gas, which has better heat insulation, sound insulation and shock resistance. For example, the thermal conductivity of polyvinyl chloride (PVC) is only 1/357 of steel and 1/1250 of aluminum. In terms of thermal insulation capacity, single-glass plastic windows are 40% higher than single-glass aluminum windows, and double-glass windows are 50% higher.

5. Wide distribution of mechanical strength and high specific strength

Some plastics are hard like stone and steel, and some are soft like paper and leather; from the hardness and tensile strength of the plastic Judging from the mechanical properties such as strength, elongation and impact strength, it has a wide distribution range and has a lot of room for use. Because plastic has a small specific gravity and high strength, it has a high specific strength.

Compared with other materials, plastics also have obvious shortcomings, such as being easy to burn, not as stiff as metal, poor in aging resistance, and not heat-resistant. Details>>

How to choose plastic products 1. Key points for purchasing plastic bottles

Common plastic bottles include mineral water bottles, carbonated drink bottles, juice bottles, etc. No matter what kind of raw material is chosen for the plastic bottle, it must first meet the requirements of non-toxicity and no odor, and these drinks mainly use polyester bottles made of PET plastic. If this kind of bottle is not very bright and clear, and the texture is particularly uneven to the touch, it is most likely made of recycled waste.

2. Key points for purchasing plastic tableware

It is recommended to choose melamine plastic for plastic tableware. It looks and feels like porcelain, is acid and alkali resistant, and has relatively high hardness and impact resistance. , long service life, can be cleaned and disinfected in a dishwasher below 120°C. You should go to regular stores to buy melamine tableware produced by authentic factories.

3. Key points when purchasing plastic bags

First of all, you must check whether the appearance of the plastic bag has a "food use" mark. Usually this logo should be on the front of the packaging bag in a more eye-catching position; secondly, look at the color. Generally speaking, the color of colored plastic bags is a colorant that is easily soluble in grease and harmful to the human body; finally, it depends on whether the plastic bag has No impurities. Put the plastic bag under sunlight or light to see if there are any black spots or holes. Plastic bags with impurities must be made from waste plastics.

4. Key points for purchasing cling film

See if there is a product description on it. If it has PE cling film or polyethylene cling film on it, you can use it with confidence; if it says If it is PVC or the material is not written, then try not to buy it. Polyethylene cling film generally has poor viscosity and transparency, and is easy to open after rubbing with hands, while polyvinyl chloride cling film has better transparency and viscosity, and is difficult to unfold after rubbing with hands, and it is easy to stick to the hands. Details>>

5. Key points for purchasing plastic toys

When purchasing toys, you must choose qualified products. Plastic toys made of inferior materials will be harmful to your baby's health. High-quality plastic toys are usually made of PVC, PP, PE and other plastic raw materials, and have a bright color. In addition, you should also pay attention to the 3C certification and label instructions of the toys. Labels such as manufacturer, place of origin, main material components, warning slogans, product certificates, etc. should also be checked. More points for purchasing commonly used plastic products>>

How to identify the pros and cons of plastic products 1. Vision

Transparent and colorless products look very transparent and free of impurities. Good quality (mostly produced from raw granular materials) such as fresh-keeping bags, cups, lunch boxes, and fresh-keeping boxes.

Products that are not very transparent or appear to have a lot of impurities are of slightly lower quality (mostly produced from raw powder materials), such as storage boxes, basins, hangers, and stools.

Opaque products are mostly inferior products (mostly produced with recycled materials, but recycled materials can be divided into many types, such as recycled materials generated by manufacturer trimming, defective products returned to the manufacturer by dealers Products) such as trash cans, trash can liners, and trash bags.

2. Smell

If it smells very light, but has a faint plastic smell, it is mostly products of better quality; if it smells strong, it usually means products of slightly lower quality. Products that smell strongly of plastic and have a pungent smell are mostly products of poor quality.

3. Touch

When you touch the edge of the product, there is no irritating feeling. The cleaner edges are probably because the mold is better and the flash is better repaired; it feels irritating to the touch. , the edges are very rough mostly because the mold is poor. Details>>

What are the hazards of plastic products? 1. The recycling value of plastic products is low. During use, plastic products are scattered in urban streets, tourist areas, water bodies, and on both sides of highways and railways, causing "visual problems". In addition to pollution, there are also potential hazards. The plastic structure is stable, not easily degraded by natural microbial bacteria, and will not separate in the natural environment for a long time. This means that if waste plastic garbage is not recycled, it will become pollutants in the environment and will continue to accumulate, causing great harm to the environment.

2. Impact on agricultural development. The continuous accumulation of waste plastic products mixed in the soil will affect the absorption of nutrients and water by crops, resulting in reduced crop yields.

3. They pose a threat to the survival of animals. Waste plastic products abandoned on land or in water are swallowed by animals as food, causing their death. Last year, 20 herdsmen families killed nearly a thousand sheep by Qinghai Lake, causing economic losses of more than 300,000 yuan. Sheep like to eat the oily residue wrapped in plastic products, but they often eat the plastic products together. Because the plastic they eat stays in the stomach for a long time and is difficult to digest, these sheep's stomachs are filled up and they can no longer eat. Things will eventually starve to death. Such things are common in zoos, pastoral areas, rural areas, and oceans.

4. Occupying land resources. Waste plastics being landfilled with garbage will not only occupy a large amount of land, but also the occupied land will not be restored for a long time, affecting the sustainable use of land. If the waste plastic products that enter the domestic garbage are landfilled, they will not degrade in 200 years. It is extremely harmful to the land, changing its pH, affecting the absorption of nutrients and water by crops, resulting in reduced agricultural production. As for plastic products abandoned in water or on land, it not only affects the environment, but also can lead to death if swallowed passively. This destroys the ecological balance.

5. High temperatures decompose toxic substances. Plastic products are not toxic. However, due to imperfect recycling equipment, crude technology, and many manufacturers without legal business licenses, recycled plastic products When the temperature reaches 65°C, toxic substances will precipitate and penetrate into the food, causing harm to important parts of the human body such as the liver, kidneys, reproductive system, and central nervous system. Details>>

Plastic household products brand 1. During festivals, it’s time for online shopping experts to show off their skills. However, faced with a wide variety of products and varying prices, they don’t know where to start?

2. During every festival, it’s time for online shopping experts to show off their skills. However, faced with a wide variety of products and varying prices, you don’t know where to start?

Industry recommended brands LOCK&LOCK, Tupperware, CHAHUA, Miaojie, IRIS, Maryya, TAILI, Citylong, LONGSTAR, Recommended reading 1. During festivals, it’s time to shop online It’s time for experts to show off their skills, but faced with a wide variety of products and varying prices, you don’t know where to start?

2. During every festival, it’s time for online shopping experts to show off their skills. However, faced with a wide variety of products and varying prices, you don’t know where to start?

01 What is clean energy? What energy does clean energy include? Clean energy is not a simple classification of energy, but refers to a technical system for the clean, efficient and systematic application of energy.

So using clean energy...

02 Which new energy vehicle is better to buy? What is the difference from ordinary fuel vehicles? Know all about new energy vehicles. What is the difference between new energy vehicles and ordinary cars? In response to the country's call for the development of new energy, many places have introduced policies to support new energy vehicles in recent years...

03 How much does it cost to charge an electric vehicle once? How much does it cost to fully charge a new energy vehicle? Due to traditional non-renewable energy sources Due to factors such as gradual depletion and increased pollution of the natural ecological environment caused by vehicle exhaust, new energy sources in all walks of life...

04 Characteristics and distribution of China's energy structure. An inventory of the top ten domestic major energy sources. Throughout mankind In the history of social development, every major progress of human civilization is accompanied by the improvement and replacement of energy. The development and utilization of energy,...

05 Gas Knowledge Encyclopedia What types of gas are there? What are the causes of gas explosions? Gas is the general term for gaseous fuels. It can burn and release heat and is used by urban residents and industrial enterprises. . There are many types of gas, the main ones are...

06 Energy Saving Guide, Household Appliances, Energy Saving Tips to Manage Power-consuming Households Household appliances have become an indispensable part of our lives, and most families have refrigerators. , air conditioners, computers, LCD TVs, lighting, etc...

07 What are dangerous goods? Dangerous Goods Label Common Dangerous Goods Emergency Response Measures Dangerous goods, that is, due to their chemical, physical or toxic properties, they can easily cause fires,...

08 Food Safety Certification Marks and Standards Food Safety Knowledge Encyclopedia There is a saying that goes well, "Food is the first priority for the people, safety is the first priority, and safety is quality." This profoundly illustrates the impact of food safety on human survival and development...< /p>

09 Energy Chemical Engineering Major Postgraduate Entrance Examination and Employment Energy Chemical Engineering Major University Ranking What is Energy Chemical Engineering? The energy and chemical engineering major is one of the first batch of undergraduate majors in the national strategic emerging industries. It is our country's solution to...

10 How to achieve safe production? A comprehensive collection of safety production operating procedures for various types of work. The safety production operating procedures are based on the jobs the employees are engaged in, the production nature of the enterprise, the characteristics of the machinery and equipment, combined with the specific situation and the experience of the masses...