The meaning of the numbers on the bottom of plastic bottles

The Society of Plastics Industry (SPI) has developed a symbol code for the type of plastic used in plastic products, which is a triangle consisting of three arrows representing the middle of the cycle, with a numerical symbol, and they attach the recycling mark of the triangle to the plastic product and use the numbers 1 through 7 and the abbreviation to refer to the resin used in the plastic species. In this way, identification of the plastic species became simple and easy, and recycling costs were drastically reduced. This SPI labeling scheme has been adopted by many *** in the world today. China developed an almost identical labeling standard in 1996.

The * goal of plastic packaging waste treatment is to recover and recycle containers, etc. as resources for reuse, in order to protect limited resources and complete the recycling of packaging containers. Among them, 28 % of PET (polyethylene terephthalate) bottles for carbonated beverages can be recycled, and HD-PE (high-density polyethylene) for milk bottles and HD-PE for soft drink bottles can also be effectively recycled.

In order to facilitate the recycling of various post-consumer plastic products, it is necessary to sort different kinds of plastics. Since there are many and complex channels of plastic consumption, and some post-consumer plastics are difficult to distinguish them simply by their appearance, it is * desirable to mark the material species on the plastic products. What are the uses and advantages and disadvantages of the different designations, you ask? The following will help you figure this out:

Plastic names - codes with corresponding abbreviated designators are shown below:

Polyethylene terephthalate --- 01 PET ( PET bottle ) such as: mineral water bottles, carbonated beverage bottles

Recommended: beverage bottles do not recycle for hot water

Use: heat-resistant to 70 ℃, only suitable for loading warm or frozen drinks, loading high-temperature liquids, or heating is easy to deformation, there are harmful substances melted out of the human body. And, scientists found that the No. 1 plastic products used for 10 months, may release carcinogens DEHP, toxic to the testicles.

Therefore, drink bottles and other used up to throw away, do not use again as a water cup, or used to do storage containers multiplied by other items, so as not to cause health problems are not worth the loss.

High density polyethylene - 02 HDPE e.g.: cleaning products, bath products

Suggestion: It is recommended not to recycle after cleaning thoroughly

Use: Can be reused after careful cleaning, but these containers are usually not well cleaned, residue of the original cleaning supplies, into a breeding ground for bacteria, you * better not recycle.

Polyvinyl chloride ---- 03 PVC such as: some decorative materials

Use: This material is prone to harmful substances when high temperature, even the manufacturing process it will be released, toxic substances with food into the body, may cause breast cancer, newborn babies congenital defects and other diseases. At present, containers of this material have been less used for packaging food. If in use, never let it be exposed to heat.

Low density polyethylene - 04 LDPE e.g.: cling film, plastic film, etc.

Suggestion: cling film do not wrap on the surface of the food into the microwave oven

Use: Heat resistance is not strong, usually, qualified PE cling film will be hot melt phenomenon when encountering temperature over 110 ℃, will leave some plastic agents that the human body can not decompose. Moreover, if you wrap food in plastic wrap and heat it, the grease in the food will easily dissolve the harmful substances in the plastic wrap. Therefore, when you put food into microwave oven, you should remove the plastic wrap first.

Polypropylene ----- 05 PP ( can withstand temperatures above 100 degrees ) e.g.: microwave lunch box

Suggestion: Remove the lid when putting into the microwave oven

Use: *** Plastic boxes that can be put into the microwave can be reused after careful cleaning. Special attention should be paid to some microwave lunch boxes, the box body is indeed made of No. 5 PP, but the lid is made of No. 1 PE, because PE can not withstand high temperatures, so it can not be put into the microwave oven with the box body. To be on the safe side, remove the lid before putting the container into the microwave oven.

Polystyrene ---- 06 PS ( heat-resistant 60-70 degrees, containing hot drinks will produce toxins, burning will release styrene ) such as: bowl of noodles boxes, fast food boxes

Suggestion: do not use microwave cooking bowl instant noodles

Use: heat and cold resistant, but can not be put into the microwave oven to avoid the release of chemicals due to high temperature. And can not be used to multiply loaded strong acid (such as orange juice), strong alkaline substances, because it will decompose bad for the human body polystyrene, easy to cause cancer. Therefore, you should try to avoid using fast food containers to pack boiling hot food.

Other plastic codes - 07 Others e.g.: water bottles, water cups, milk bottles

Suggestion: PC glue releases BPA when exposed to heat

Use: A material that is heavily used, especially in milk bottles, is controversial because it contains Bisphenol A. City University of Hong Kong Department of Biology and Chemistry Associate Professor Lam Hon Wah said, in theory, as long as the process of making PC, Bisphenol A *** transformed into plastic structure, it means that the product is completely free of Bisphenol A, not to mention the release. However, if a small amount of BPA is not transformed into the plastic structure of PC, it may be released into food or drink. Therefore, it is better to be careful and take extra care when using this plastic container.

Application profile:

The higher the temperature of BPA residue in PC, the more it will be released and the faster it will be released. Therefore, PC water bottles should not be used to hold hot water, so as not to increase the speed and concentration of BPA (if any) release. If your water bottle has the number 7, the following methods can reduce the risk:

● Do not heat it when using it.

Do not wash the kettle in the dishwasher or dish dryer.

Do not expose the kettle to direct sunlight.

Wash the kettle with baking soda and warm water before use and dry it naturally at room temperature. This is because BPA will be released more at the * first use and long-term use.

● If the container has any drop or breakage, it is recommended to stop using it, because plastic products with fine pitted surface can easily hide bacteria.

● Avoid repeated use of plastic utensils that have aged.

The PP, PE and PVC are the abbreviations of the English names. The Chinese names are polypropylene, polyethylene, polyvinyl chloride, and the full English names are: polypropylene, polyethylene, polyvinyl chloride.

We commonly see some old slippers made of PVC, they are soft in summer and hard in winter, which has a lot to do with the temperature sensitivity of PVC, which decomposes toxic gas - chlorine gas at high temperatures. The density of the three PVC * large.

Ordinary plastic bags are made of PE, its toughness is better, PE is also divided into HDPE (high-density polyethylene) and LDPE (low-density polyethylene), the difference in density, resulting in some of its performance and a great difference.

PP is a safer plastic in the plastic, the general food on the bag is made of it, of course, PP also has a grade, packaging food with must be food-grade. PP in the three density * small, can float on the surface.

Like these polymer materials can generally be added to some other materials for its modification, so that in its overall performance or in a particular aspect of performance, to be used for special purposes, of course, after the modification of the price will sometimes increase significantly.