Plastics are an indispensable material in modern society, but their widespread use also brings environmental challenges. In order to recycle and utilize plastics more effectively, it is essential to understand their classification and marking codes. This article introduces in detail the types of plastics, the meaning of marking codes, the applications and recycling of common plastics, and helps readers understand the use and recycling mechanism of plastics more clearly through tables and data analysis.
Currently, there are more than 100 known plastic materials, which can be mainly divided into the following three categories:
General purpose plastics: low cost, widely used in daily life.
Engineering plastics: excellent performance, heat resistance, wear resistance, mostly used in automobiles, electronics and other fields.
Special plastics: with special properties, such as high temperature resistance and radiation resistance, used in high-end fields such as aerospace, medical devices, etc.
Among common plastics, the American Plastics Industry Association (SPI) has developed a set of recycling marking codes from 1 to 7 to identify the resin types of plastics. This marking scheme has been widely used worldwide.
| Code | Material name | English abbreviation | Main features | Main use |
|---|---|---|---|---|
| 01 | Polyethylene terephthalate | PET | Transparent, lightweight, acid and alkali resistant | Mineral water bottles, carbonated beverage bottles |
| 02 | High-density polyethylene | HDPE | High strength, corrosion resistance | Milk bottles, cleaning supplies containers |
| 03 | Polyvinyl chloride | PVC | Chemical resistance, not high temperature resistance | Water pipes, floors, building materials |
| 04 | Low-density polyethylene | LDPE | Soft and tough | Cling film, plastic bags |
| 05 | Polypropylene | PP | High temperature resistant | Microwave lunch boxes, medicine bottles |
| 06 | Polystyrene | PS | Lightweight, fragile, low heat resistance | Disposable tableware, foam plastics |
| 07 | Other plastics | Others | Complex and diverse | Kettles, milk bottles, PC materials |
Application: mineral water bottles, carbonated beverage bottles.
Note: heat-resistant up to 70°C, not suitable for holding high-temperature liquids to prevent harmful substances from dissolving.
Application: milk bottles, cleaning product containers.
Note: reusable, but difficult to clean, and easy to become a breeding ground for bacteria.
Application: water pipes, floors, window frames.
Note: harmful substances may be released at high temperatures, not suitable for food packaging.
Application: plastic wrap, plastic bags.
Note: Poor heat resistance, cannot be used for microwave heating.
Application: Microwave lunch boxes, medicine bottles.
Note: Good heat resistance, but need to pay attention to the lid material, some lids use non-heat-resistant PE material.
Application: Disposable tableware, foam plastics.
Note: Poor heat resistance, easy to release harmful substances when exposed to high temperature.
Application: Kettles, baby bottles, CDs.
Note: This type of plastic is complex, some may contain bisphenol A (BPA), need to be used with caution.
| Code | Common applications | Recyclable or not | Recycling and reuse |
|---|---|---|---|
| 01 | Beverage bottles | Yes | Remade into fibers, plastic packaging |
| 02 | Cleaning product bottles | Yes | Made into pipes, pallets |
| 03 | Building materials | No | Difficult to recycle, may be incinerated |
| 04 | Plastic bags | No | The recycling rate of degradable plastic bags is low |
| 05 | Food containers | Yes | Recyclable and reused, converted into plastic products |
| 06 | Foam plastics | No | Most are not recyclable and easily pollute the environment |
| 07 | Kettles, milk bottles | Depends on the specific material | Requires special recycling |
Currently, the recycling rate of plastics is low. Taking PET as an example, its global recycling rate is about 20%-30%, which is much lower than the recycling rate of metal and glass. The main challenges of plastic recycling include:
Imperfect recycling system: Many countries lack systematic sorting and recycling facilities.
Mixed plastics are difficult to handle: Different plastics are difficult to separate after mixing, resulting in high recycling costs.
Lack of public environmental awareness: Residents in some areas lack recycling awareness, resulting in the failure to effectively sort plastic waste.
In order to increase the recycling rate of plastics, many countries have taken actions, such as:
EU: Plans to make all plastic packaging recyclable by 2030.
China: Promote a garbage sorting system to increase the recycling rate of plastics.
US: Some states ban the use of disposable plastic bags and promote the development of degradable plastics.
The type and labeling code of plastics are crucial for the correct use and recycling of plastics. By understanding the characteristics of different types of plastics and how to recycle them in detail, we can make better use of plastic resources while reducing environmental pollution. I hope this article can help readers establish a more scientific concept of plastic use and recycling and jointly promote sustainable development.
Choose recyclable plastic products and reduce the use of disposable plastics.
Pay attention to the recycling logo of plastics and classify them correctly.
Pay attention to environmental protection policies and contribute to a green future.
Contact: Smile Kuan
Phone: +86 134 2472 9214
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