一般由内胆、保温层和外壳组成。

Generally, it is made up of internal bladder, insulation layer and shell.

1.内胆：通常用sus304不锈钢焊接而成，具有较高的耐腐蚀性，防污染性。

1. internal bladder: usually welded with SUS304 stainless steel, with high corrosion resistance and pollution resistance.

2.保温层：分为几类：岩棉、橡塑海棉、聚氨酯发泡等等，以聚氨酯发泡效果最好。

2. insulation layer: divided into several types: rock wool, rubber plastic sponge, polyurethane foam, and so on, with polyurethane foam best.

3.外壳：由于外壳主要起到保护保温层和美观的作用，一般用较薄的不锈钢板制成，为了降低成本，很多时候用彩板制作，要注意防腐。

3. shell: because the shell is mainly used to protect the insulation and beauty, it is usually made of thin stainless steel sheet. In order to reduce the cost, many times we use color plate to make, and we should pay attention to anti-corrosion.