Plastic Molded trolleys are generally the traditional style of mass production. Pieces of different grade of plastic are forced into a mold to create mass produced components. The different grades of plastic over the years, has shown up a lot of inconsistencies in trolley construction many of these styles of trolley do break and crack under impact e.g. assembly. Structural foam construction has air pockets blown into the mold making the construction of the trolley lighter and also its claimed to be stronger. Our experience with these trolleys from China, Taiwan and the USA does not suggest any of the claims made.