What do the numerical symbols 1, 2, 3, 4, 5, 6, and 7 on the bottom of plastic cups represent?

The numerical symbols on the bottom of plastic cups are typically part of a triangular symbol known as the "resin code" or "recycling identification number," http://www.umbottle.com/ProductsDetail-VB-10236.htmlcontaining a number inside. This number represents the type of plastic used in the cup, and each type of plastic has unique properties and uses. Here are common resin codes and the corresponding plastic types:

#1 - Polyethylene Terephthalate (PET):

This plastic is commonly used to make transparent beverage bottles, food containers, http://www.umbottle.com/ProductsDetail-VB-10236.htmland fibers. It is easily recyclable and is often used in packaging food and beverages.

#2 - High-Density Polyethylene (HDPE):

HDPE is a harder plastic used for making bottles, containers, detergent bottles, cosmetic bottles, and some household items. http://www.umbottle.com/ProductsDetail-VB-10236.htmlIt has good corrosion resistance and toughness.

#3 - Polyvinyl Chloride (PVC):

PVC is a plastic used for making pipes, plastic wrap, flooring, http://www.umbottle.com/ProductsDetail-VB-10236.htmland more. However, it contains toxic substances, so caution is needed in recycling and disposal.

#4 - Low-Density Polyethylene (LDPE):

LDPE is a soft and heat-resistant plastic commonly used for making plastic bags, packaging films, disposable gloves, etc.

#5 - Polypropylene (PP):

PP is a high-temperature and chemically resistant plastic used for making food containers, medical supplies, household items, etc.

#6 - Polystyrene (PS):

PS is commonly used for foam plastics, such as foam cups, foam boxes, and some household items.

#7 - Other Plastics or Mixtures:

This code represents other types of plastics or composite materials that do not fall into the categories 1 to 6. http://www.umbottle.com/ProductsDetail-VB-10236.htmlThis category includes many different types of plastics, some of which may not be easily recyclable.

These numerical codes help people identify and categorize different types of plastics, facilitating recycling and reuse. However, it's important to note that even with recycling identification numbers,http://www.umbottle.com/ProductsDetail-VB-10236.html local recycling facilities and regulations may affect the ability to recycle specific types of plastics.