It must be mentioned here that patents protect the right to prohibit others from using them.
Even if you apply for a patent, it doesn't mean that you can produce what your patent protects.
Just like your situation, you should consider whether you are still using other people's patents in the production process of your products, and if so, you need permission from others.
Of course, it has to be analyzed in specific cases. First of all, whether the patent you are suspected of infringing is a valid patent, if you can prove it is invalid (lack of novelty, etc.). ), you can use it boldly and sue you later. You can submit the prepared materials and declare his patent invalid.
Then, for the process, even if you use it for infringement, it is difficult for others to investigate and collect evidence, because the process is in the production process and the final product cannot be reflected, so if he wants to sue you, it is difficult for him to investigate and collect evidence.