Abstract: Disposable insulated lunch boxes are commonly used for takeout to keep meals warm. There are seven types of disposable insulated boxes: plastic type, cardboard type, starch type, and pulp molded type. It should be noted that some materials It can be heated in the microwave, but some cannot. The quality of take-out insulated lunch boxes can be good or bad. You can judge the quality of take-out insulated lunch boxes by immersing the lunch boxes in water, feeling whether the inner wall of the lunch box is rough, and tearing the lunch boxes to test the toughness of the take-out boxes. Let’s learn about the types and quality identification methods of disposable insulated lunch boxes! 1. What are the types of disposable insulated lunch boxes

1. Plastic type

Disposable lunch boxes made of plastic mainly include PP polypropylene and PS polystyrene. They are all non-toxic, tasteless and odorless. PP is relatively soft. Generally, the use temperature of PP is -6 degrees to +120 degrees, so it is especially suitable for holding hot rice and hot dishes. It can be heated in a microwave oven or even steamed in a steam cabinet. The use temperature of non-toxic PP can be controlled from -18 degrees to +110 degrees. In addition to being heated to 100 degrees for use, lunch boxes made of this kind of PP can also be placed in the refrigerator for use.

PS is hard and transparent, but easy to tear. PS begins to soften when the operating temperature reaches 75 degrees, so it is not suitable for serving hot meals and dishes. However, PS has good low-temperature performance and is the best choice for ice cream. The best packaging materials.

In order to reduce costs, some lunch box factories use PP as the box and PS as the lid. The advantage is that the lid is transparent and PS is hard and can be made of thinner sheets to reduce costs. However, this design Consumers must understand the difference between the two materials and remember not to heat the entire box of rice with the lid in the microwave.

2. Cardboard type

The cardboard snack box is made of 300-350 grams of bleached sulfate wood pulp cardboard as raw material, which is die-cut and bonded through a stamping and forming process similar to sheet metal processing. Made by die cutting, pressing, shaping and other processes. In order to prevent oil or water seepage, it is necessary to coat the surface with a film or apply chemical additives. It is non-toxic and has no side effects on the human body during production and use. However, the quality requirements for cardboard are higher, and the cost also increases.

3. Starch type

Edible fast food boxes made from starch, as the name suggests, are made from starchy plants and added with dietary fiber and other edible additives. It is made by stirring and kneading. It is refined using biological compounding, polysaccharide cross-linking, calcium ion chelation and other technologies. The operating temperature is -10 degrees to +120 degrees, so it is especially suitable for holding hot rice and hot dishes. It can be used in the microwave oven. It can be heated inside or placed in the refrigerator for use.

4. Pulp molding type

Pulp and purify wood pulp or reed, bagasse, wheat straw, rice straw and other annual herbaceous plant fiber pulp, and add an appropriate amount of non-toxic chemical additives , formed, dried, shaped, shaped, trimmed and sterilized. The aesthetics of the product are not high and it will also increase the pollution of waste water.

5. Plant fiber type

In terms of environmental protection, plant fiber lunch boxes have obvious advantages. They are made of plant fibers extracted from rice straw, rice husk, sugarcane bagasse, etc. as raw materials. , add molding agent, adhesive, water-resistant agent and other additives, stir and form through the molding machine, and then undergo post-processing such as drying, shaping, and disinfection. These agricultural scraps can become industrial raw materials and contribute to the comprehensive utilization of agricultural resources.

6. Biodegradable plastic lunch boxes

The raw material for manufacturing such lunch boxes is degradable plastic. The so-called degradable plastic means adding a certain amount of additives during the production process of plastic. Such as photosensitizer, starch and other raw materials, in this way, after the degradable plastic products are used and discarded in nature for three months, they can be decomposed into fragments from the complete shape, thus improving the environment.

7. Biodegradable lunch box

Biodegradable lunch box is a relatively advanced environmentally friendly product. It uses starch as the main raw material, adds annual growth period plant fiber powder and special additives, and is processed by chemical and physical methods to make a fully biodegradable fast food box. Because starch is a biodegradable natural polymer, it is decomposed into glucose and finally water and carbon dioxide under the action of microorganisms.

In addition, the materials mixed with it are also fully degradable materials, so it can be said that it has no impact on the environment. The main sources of raw material starch can be corn, potatoes, sweet potatoes, cassava and other annual growth plants. Naturally, most of the biodegradable production raw materials are food crops, which can completely replace foam lunch boxes without any pollution to the environment.

2. How to identify the quality of take-out insulated lunch boxes

1. Shen: Fill a glass with water and tear it off from the pure polypropylene (PP) plastic lunch box Put a small piece into the glass and immerse it completely in the water to see if the plastic piece will float to the surface. When experimenting at home, you don’t need to tear the plastic lunch box, just put the complete lunch box into a laundry tub filled with water. Remember to completely immerse the lunch box in the water.

2. Touch: The inner wall of the box is rough and feels astringent, which means there are solid residues on the inner wall; when exposed to light, there are obvious irregular small black spots in the box material; if there are any, it means it is of poor quality. product.

3. Tear: High-quality lunch boxes are made of new PP plastic, which has good toughness and high hardness and cannot be torn by hand; inferior lunch boxes feel soft and will break if you tear them lightly. .

4. Appearance: You can identify it by looking at the QS logo and number on the lunch box. Starting from June 1, 2010, the words "Quality and Safety" will be changed to "Production License" in the QS mark on the food packaging produced by certified enterprises.