Illegal. First of all, it is illegal to be a production unit without a business license, which involves pre-production. Illegal acts are more serious, even more serious. For example, some foods are produced without a license, which may also involve criminal offences. As for imitating other people's products, first of all, you can't hit other people's trademarks, otherwise you will infringe on the exclusive right of registered trademarks of others. Secondly, other people's products are patented, so you can't produce them without authorization.