Finish grinder

Types of finish grinders

A finish grinder is the final stage in the milling process, used to create a fine, smooth powder from raw material. A finish grinder is sometimes called a pelletizer or granulator, and it comes in roller-driven and air-swept variations. Both types of finish grinders are commonly used in the machinery industry to process all kinds of materials, from plastic to wood.

• Roller-driven finish grinders

  Roller-driven grinder mills use gravity to pull material through the rolls. As material moves through the rolls, they crush and break the material down into smaller particles and eventually a final powder. This type of finish grinder is often used to process hardwoods because they efficiently break down tough fibers. Some roller-driven finish grinders have a combination of rollers and hammers to further refine material.

• Air-swept finish grinders

  Air-swept grinders use airflow to move material through the mill. A fan or blower creates enough centrifugal force to pull material into the mill, where it's processed and ejected through a baghouse. This type of finish grinder is ideal for light, fluffy materials like cotton or fiberglass that may get stuck in roller-driven grinders. Air-swept grinders can also process various material shapes and densities more efficiently than other methods.

Some finish grinders combine air-swept and roller-driven technology. For example, a finish grinder may have a fan-assisted hopper that uses gravity and air to feed material into the mill. Another hybrid type of finisher is the airless grinder, which applies high-velocity impact to break down material. It uses a high-speed rotor to throw material against a diamond-shaped impacted chamber.

Specification and maintenance of finish grinders

Die grinders come in various horsepower ratings, from about one to three horsepower. Pneumatic units typically require about 4 cfm at 90 psi to operate. Electric units pull around ten amps, while cordless electric die grinders run on 20-volt lithium-ion batteries. The spindle size is either ½ inch or ¾ inch, which accommodates different collets. Pneumatic die grinders usually run between 20,000 to 30,000 rpm. The speed of electric die grinders is lower, but they have more torque and may run between 10,000 to 25,000 rpm.

Maintaining a die grinder involves keeping it clean. Wipe it down when finished each day to avoid dirt and debris buildup. Check the power source cable for any damage or exposed wiring. Coil the power cable when storing it away. Pneumatic models need lubrication to keep the air motor spinning smoothly, so they need one drop of air tool oil in the air inlet daily. The tool oil also prevents moisture buildup inside the air motor. Lubricate all moving parts of electric models with lightweight oil on a weekly basis. Regularly clean air filters on pneumatic units to prevent clogging and flush tool oil from the device monthly.

Usage scenarios for finish grinders

The role of a finish grinder is to take a rough, unfinished product and give it the final polish and finishing touches. It is employed on all kinds of materials from wood to various types of metals and concrete.

For the woodworking industry, the finish sander is used extensively by cabinet makers, furniture builders, window and door manufacturers and many other businesses that work with solid wood or laminated material. In addition to polishing and refining edges, wood finish grinders are often used to add decorative elements to products, such as grooves and roundovers.

How to choose finish grinders

Both hardwood and softwood finish grinders can be easily found in the market, but people who are buying them for business purposes have to be more careful. The following tips will help business buyers choose the right industrial wood finish grinder.

• Purpose of grinder

  Different businesses have different purposes for getting wood finish grinders. Some will use them for complete destruction of wood waste as as a feeding machine for biomass power generators while others will for finer particles of pulverized wood for purpose such as animal bedding. Hence, buyers should be clear about their purpose before purchasing a grinder. This will help them choose a machine that's suitable for their specific needs.

• Capacity and power

  Consider the grinder's capacity and power. Select a grinder that can handle the expected volume of wood waste. Ensure the motor power is sufficient for the tasks. This is an important factor because high-powered grinders not only work efficiently, but also have longer lifespans.

• Maintenance requirements

  When choosing a wood finish grinder, take into account its maintenance requirements. Select a machine with low maintenance demands and robust construction to minimize downtime and maintenance costs. A wood grinder machine that requires frequent maintenance can disrupt workflow and lead to increased expenses.

FAQ

Q1. How does a finish grinder work?

A1. A finish grinder uses a belt or wheel to apply a high level of pressure and friction to the wood. It may also use a combination of all three processes – sanding, scraping, and burning – over and under the entire surface area of the board.

Q2. Is a finish grinder dust collection system needed?

A2. A finish grinder with a good dust collection system will make the process a lot cleaner and help keep production moving.

Q3. Can a pneumatic finish grinder be used for any type of metal?

A3. No. Each type of metal has its own unique properties that require specific handling characteristics. Additionally, some metals may be too thin or contoured for finish grinding to economize the yield.

Q4. Can a finish grinder be used in homes or industries?

A4. Generally, a finish grinder is used in various manufacturing industries to process raw materials into finished products. Its widespread use can significantly streamline production processes, thereby enhancing overall efficiency. Nonetheless, residual grinders can also be beneficially utilised in domestic settings.