I think food grade plastic products trademark registration is in Class 17

A trademark is a sign that distinguishes the source of goods or services. Each registered trademark is designated for a certain product. or service. It is precisely for the needs of trademark retrieval, review, and management that certain goods with the same attributes are grouped together into one category, and all goods and services are divided into 45 categories to form a trademark Classification Schedule - "Classification of Goods and Services for Trademark Registration".

As far as I know, the commonly used plastic types are: polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS) and acrylonitrile-butadiene- Styrenic polymer (ABS). 1. Polyethylene Polyethylene plastic is relatively soft and has a waxy feel to the touch. It is lighter in weight than similar plastics and has a certain degree of transparency. The flame is blue when burning. The main application areas include: plastic wrap, vest-type plastic bags, plastic food bags, baby bottles, buckets, kettles, etc. 2. Polypropylene Polypropylene is a thermoplastic resin made from the polymerization of propylene. Mainly used in household appliance injection parts, modified raw materials, daily injection products, pipes, etc. 3. Polyvinyl chloride (PVC) was once the most widely produced general plastic in the world and is widely used. It is widely used in building materials, industrial products, daily necessities, floor leather, floor tiles, artificial leather, pipes, wires and cables, packaging films, bottles, foam materials, sealing materials, fibers, etc. 4. Polystyrene Polystyrene plastic is widely used in optical instruments, chemical industry sectors and daily necessities. It is used to make tea trays, sugar bowls, soap boxes, cigarette cases, student rulers, combs, etc. Due to its certain air permeability, it can also be used as a good food packaging material when made into film products. 5. ABS plastic ABS has good electrical insulation and is almost unaffected by temperature, humidity and frequency, and can be used in most environments. The largest application areas of ABS resin are automobiles, electronic appliances and building materials.