1, plastic type
Disposable lunch boxes made of plastic mainly include PP, PP and PS polystyrene, which are non-toxic, tasteless and odorless. PP is soft. Generally, the temperature of PP is -6 degrees to+120 degrees, so it is especially suitable for holding hot meals and dishes. It can be heated in a microwave oven and even cooked in a steam cabinet. The use temperature of modified PP can be controlled from-18 to +6520.
PS is hard and transparent, but it is easy to tear. PS begins to soften when the temperature reaches 75 degrees, and it is not suitable for hot meals and hot dishes. But PS has good low temperature performance and is the best packaging material for ice cream.
In order to reduce the cost, some lunch box factories use PP as the box body and PS as the box cover. Advantages are that the cover is transparent, PS is hard, and thinner materials can be used to reduce costs. But consumers must understand the difference between the two materials in this design, and remember not to heat the whole lunch box and lid in the microwave oven.
2, cardboard type
The cardboard snack box is made of 300-350g bleached kraft pulp cardboard through stamping process similar to sheet metal processing, die-cutting bonding or die-cutting pressing, molding and other processes. In order to prevent oil leakage or water seepage, it is necessary to coat the surface with a film or chemical additives. It is non-toxic and has no side effects on human body during production and use. However, the quality of cardboard is higher and the cost is increased.
3. Starch type
As the name implies, an edible snack box made of starch is made of starch plants, dietary fiber and other edible additives through stirring and kneading. It is refined by bio-compounding, polysaccharide crosslinking, calcium ion chelation and other technologies. The temperature is-10℃ to+120℃, which is especially suitable for holding hot rice and hot dishes and can be heated in microwave oven.
4. Pulp molding
Pulping and purifying wood pulp or millet fiber pulp such as reed, bagasse, wheat straw and rice straw, adding appropriate amount of nontoxic chemical additives, shaping, drying, shaping, trimming and sterilizing. The aesthetics of the product is not high, and it will also increase the pollution of wastewater.
5, plant fiber types
In terms of environmental advantages, plant fiber lunch boxes have obvious advantages. It is made of plant fiber extracted from rice straw, rice husk and bagasse, and added with additives such as molding agent, adhesive and water repellent, and then stirred, dried, shaped and disinfected by a molding machine. These agricultural leftovers can become industrial raw materials, which is beneficial to the comprehensive utilization of agricultural resources.
6, degradable plastic lunch box
The raw material of this lunch box is degradable plastic. The so-called degradable plastic means adding a certain amount of additives, such as photosensitizer, starch and other raw materials, in the plastic production process. In this way, after being used up and exposed to nature for three months, degradable plastic products can be decomposed into pieces from a complete shape, thus improving the environment.
7. biodegradable lunch box
Biodegradable lunch box is an advanced environmental protection product. It uses starch as the main raw material, adds annual plant fiber powder and special additives, and makes biodegradable fast food boxes by chemical and physical methods. Because starch is a biodegradable natural polymer, it is decomposed into glucose under the action of microorganisms, and finally into water and carbon dioxide.
In addition, the materials mixed with it are also fully degradable materials, which can be said to have no impact on the environment. The main sources of raw starch can be annual plants, such as corn, potato, sweet potato and cassava. Naturally, most of the raw materials produced by biodegradation are food crops, which have no pollution to the environment and can completely replace foam lunch boxes.
Second, how to distinguish the quality of take-away insulated lunch boxes?
1. Sinking: Fill a glass with water, tear a small piece from a pure polypropylene (PP) plastic lunch box and put it all into the glass. Immerse it completely in water to see if the plastic sheet will surface. When doing experiments at home, you can put the complete lunch box into the washbasin filled with water without tearing the plastic lunch box. Remember to completely immerse the lunch box in the water.
2. Touch: the inner wall of the box is rough and feels rough, indicating that there are solid residues on the inner wall; For illumination, the box surface material has obvious irregular small black spots; If it is, it means it is inferior.
3, tear: high-quality lunch box made of brand-new PP plastic, good toughness, high hardness, can not be torn by hand; Inferior lunch boxes are soft to the touch, and they will break when they are gently torn.
4. Appearance: it can be distinguished by whether there is a QS logo and number on the lunch box. 20 10 from June 1 day, 2008, the QS mark on the food packaging produced by all certified enterprises will be changed to "production license".