Chippers and Grinders
In the biomass and waste-to-fuel industries, wood and green waste grinders and chippers are used in a variety of settings for reducing wood to a more desirable size. Grinders are typically high-speed hammermills. The machines hammer woody material into smaller pieces of various sizes, resulting in a shredded appearance. Grinders are very tolerant of non-woody contaminants such as nails, rocks and dirt, and are often used to process wood which may contain non-wood materials. Grinders are typically available in horizontal feed and vertical feed designs, stationary and portable.
Chippers differ from grinders in that they contain sharp knives that cut and produce a uniform, thin and somewhat rectangular product. Chippers are not tolerant of non-wood contaminants and can suffer substantial damage or wear whenever exposed to nails, rocks or dirt. Large chippers are primarily used for processing whole trees and are not often used for processing wood waste materials. Small chippers process branches and other smaller scale items.