Plastic

Plastic shopping bags are packaging materials made primarily from polyolefins with other substances added as needed. Polyolefins are mainly polyethylenes (PE), commonly known as plasticizers. Main products include four types: low-density polyethylene or high-pressure polyethylene (LDPE), high-density polyethylene or low-pressure polyethylene (HDPE), linear low-density polyethylene (LLDPE), and metallocene polyethylene (mLLDPE). To reduce costs, most plastic shopping bags are filled with about 30% calcium carbonate, which does not produce toxic gases when incinerated. Newly established national standards for plastic shopping bags classify them into three types:

General plastic shopping bags—made from polyolefins and fillers. These bags are not biodegradable and do not decompose outdoors. They are highly recyclable and can be recycled multiple times. While the recycled material's performance may slightly decrease, it can still be used to manufacture shopping bags and garbage bags with lower performance requirements and stricter color requirements. The issue is whether they can be collected.

Starch-based plastic shopping bags—These bags primarily use modified starch, with small amounts of other biodegradable materials added to improve performance. These bags biodegrade naturally when disposed of outdoors after use.

Plastic-degrading shopping bags—These bags are made from completely biodegradable plastics. They completely decompose into small molecular microorganisms when disposed of outdoors, causing no environmental pollution, and are therefore popular overseas. Depending on the composition of the completely biodegradable plastic, they can be divided into three categories:

(1) PLA and PHA biodegradable plastics synthesized using natural starch and biofermentation methods have limited potential for development due to their high food consumption.

(2) Aliphatic polycarbonate (APC) biodegradable plastics synthesized from carbon dioxide are attracting attention. Using carbon dioxide, an industrial byproduct, as a raw material avoids food consumption, reduces carbide emissions, and offers a dual benefit of mitigating global warming caused by greenhouse gases.

(3) While not a common plastic solvent, the complete decomposition of the product shows promise for future industrialization, similar to reliable biodegradable materials.

Non-woven fabric

Non-woven shopping bags are not made of plastic cloth. Many people mistakenly believe the fabric is a natural material. Commonly used raw materials for non-woven fabrics are polypropylene (abbreviated as PP, commonly known as propylene) and polyethylene terephthalate (abbreviated as PET, commonly known as Teteron). PP, in particular, is the same as the PE in plastic shopping bags, belonging to the five major general-purpose plastics and is a type of plastic that will not decompose even after 50 years of use. The commonly called eco-friendly non-woven shopping bags are made from polypropylene fibers through a special process. In essence, polypropylene (PP), a typical type of plastic, belongs to the category of shopping bags and, like common plastic shopping bags, cannot be completely decomposed.

In terms of cost-effectiveness, under the same conditions, the strength of non-woven bags is inferior to plastic bags, and they are not waterproof. Their price is also several times higher than plastic bags. Incidentally, non-woven shopping bags made from two or more materials are more difficult to recycle than ordinary plastic shopping bags.

Paper

Paper has poor strength and water resistance, making it unsuitable for packaging many water-based products like seafood, and it struggles to support heavier metal products. The main raw material for paper is wood. The world's forest resources are extremely scarce, representing a significant waste of environmental resources. The paper manufacturing process also causes significant water pollution. Paper mills across the country are like rats running through the streets, constantly being attacked. Therefore, using large quantities of paper bags represents a significant waste of environmental resources and causes significant environmental pollution.

Cotton and linen

Cotton and linen shopping bags are stronger than paper bags and can be reused multiple times, but they also lack water resistance. While reusability is an advantage, what happens when the bag gets dirty? Washing is common, but this wastes water, detergent containing phosphorus pollutes the soil, and simple water washing doesn't eliminate bacteria.

Paper scraps

1. For general dried goods, it is suggested to use recycled paper from the United States or Europe, controlling the production of base paper according to the A or B grade cowhide cardboard technical indicators. Layering may or may not be done depending on whether complex patterns or advertisements are printed. The page weight is 135-150 grams/m2. A 25x20x15cm paper bag can withstand 8-15 kg.

2. If it needs to withstand a certain amount of moisture, all recycled paper can be used. However, add 0.5-1.0% wet strength agent to the above standard. A wet strength of 10-15% of the dry strength is acceptable.

3. Similarly, all recycled paper shopping bags can be used for meat and other wet goods. This requires adding an eco-friendly oil-repellent agent to the pulp during the papermaking process or applying it to the surface. A water-soluble or degradable resin can also be secondary sprayed onto the cardboard of a strong cowhide case.

4. Many manufacturers in mainland China have already developed all recycled paper to include liner paper. In other words, when making paper, a bonding agent is added between two layers of slurry, using the principle of fiber entering water-soluble gauze. This type of paper can reach the strength of four-ply kraft paper, completely replacing ordinary cement bag paper. Similarly, a single sheet of paper can also be used for shopping bags.

5. These products are safe and environmentally friendly.