Wet type polyurethane (PU) leather is produced by coating a backing material, typically made of fabric or non-woven material, with a liquid PU polymer. The specific production process for wet type PU leather typically involves the following steps:

1. First, the backing material is prepared by cutting it to the desired size and shape.
2. The liquid PU polymer is then mixed according to the manufacturer’s specifications and is applied to the backing material using a coating process such as knife coating, roller coating, or curtain coating.
3. In some cases, the liquid mixture may be poured into a liquid chemical tank to allow it to cure and form the desired shape or structure. This process is commonly used in the production of certain types of PU products, such as automotive parts or shoes, where a more flexible and durable material is needed.
4. The coated backing material is then placed into an oven or other heating device to accelerate the curing process and allow the PU polymer to form a flexible, durable coating on the surface of the material.
5. As the PU polymer cures, it reacts with the moisture in the air to form a flexible, durable coating that is similar in appearance and feel to natural leather.
6. Once the curing process is complete, the PU leather is removed from the oven and is ready for use.

Overall, the production process for wet type PU leather is relatively complex and requires careful control of the coating process, temperature, and curing time to ensure that the final product has the desired properties and appearance. The technical aspects of the production process include the precise mixing of the liquid PU polymer, the use of specialized coating equipment, and the control of the curing temperature and time to ensure that the final product has the desired properties. In some cases, the use of a liquid chemical tank may be necessary to produce certain types of PU products.