The brake press, also known as press brakes are very useful shaping sheet metal. Typically they work with a table below which holds the die and a moveable beam above where the punch is located. There are several types of brake presses available and they are described by the types of force applied in the process.
Mechanical Press – A clutch is used along with a flywheel to operate a crank. Mechanical presses are known for their speed and accuracy.
Hydraulic Press – Uses two hydraulic cylinders located on the sides of the press. They move the upper beam.
Servo-electric Press – Exerts force by driving a belt drive or ballscrew with a servo-motor (a motor with encoders to provide accurate positioning and speed).
Pneumatic Press – Uses air pressure to provide force.
Mechanical presses have long been the dominant type in the world of machining. But since the 1950s, hydraulic presses have become the most popular as a result of advances in hydraulic and computer technologies. Now, hydraulic presses are known to be very reliable and accurate. They are also considered a safe option because the ram’s motion can be stopped much easier than that of flywheel-driven mechanical presses. Servo-electric and pneumatic presses are ideal for processes requiring lower amounts of force (tonnage).
In the machining world, “food-grade” is a term that refers to a specific type of finish for metal products. Food-grade means that the surfaces of the metals used are safe enough and clean enough to process food on and also fairly easy to clean after using. For this reason, food-grade metals must not contain divots or grooves as those will likely allow bacteria to grow. The metals must also be able to withstand the corrosive effects from processing food as well as from cleaning with chemical solutions on the surfaces.
Most often, a food-grade finish is one with a finish at the high end of Number 4 (brushed). To achieve this finish, a high-grit abrasive ranging from 150 to 220 should be used. The surface roughness average (Ra) measured in micro-inches will dictate the success of the finish. For the majority of food-grade finishes, 60-36 Ra is acceptable. But if the surfaces will be used for dairy products (milk, etc.), the finish should be finer since these products carry more bacteria and spoil quickly.
Choosing the Right Tool
Finishers/Wraparound Pipe Belt Sanders
Flex Pipe Belt Sander LBR 1506 VRA
These are multi-tasking machines that can perform several functions. These machines can grind flat surfaces and removes weld seams. The sanding belts on these machines can also follow the specific contours of pipes.
BD-300 Linear Finisher
These types of machines are suitable for long, flat surfaces without streaking as well as finishing in corners. For brushing, deburring, and blending, these are the machines to use.
Finger Belt Sanders/Wraparound Pipe Sanders
Flex LBS 1105VE Finger Belt Sander
These machines are specifically suited to perform one task. They are perfect for tight spaces and angles because. They use narrow abrasives and are good in smaller areas.
Deburring – What is a burr? Occasionally, you will notice small pieces of protruding metal remaining after you’ve finished modifying an item. These pieces are called burrs and they can ruin an otherwise perfect process.
In the machining business, we see far too many people making mistakes when deciding whether
their metal needs graining, finishing, or deburring. It is often assumed that you could simply run
the metal through a sanding or graining machine in order to remove the burrs. This sounds good on
paper but in reality, there are many factors that lead to burrs in the metal and there are just as many
variations in the deburring process. The first thing to determine is what type of burr you have.
Typically, burrs fall into two categories: thermal and mechanical. Thermal burrs are the result of
oxyfuel or laser cutting while mechanical burrs result from shearing or from punching holes when
the punch and die are not fitting perfectly.
Although the graining process (which involves using a sanding belt on the metal surface) is
commonly referred to as deburring, it does not actually remove any burrs. It can affect the shape
and/or position of the burr by making it sharper but it will not completely remove it. To remove the
burr, a deburring and graining machine is needed. These machines will have two or more heads.
One head will have a sanding belt to knock the burr down and the other head with have a brush
which can eliminate the burr as well as give a radius to the edge. Above is an FP-4075W Finishing-Deburring Machine (wet)
Also to be considered is whether you want to use a wet or dry machine. A wet machine will
keep the belt in peak condition longer than a dry machine. A wet machine will also offer a better
finish and help remove grit from the parts. The downside is the amount of maintenance required.
Dry machines, though requiring less maintenance can be dangerous if not used properly. For
example, processing aluminum and stainless steel with a dry machine can cause an explosion if the
dust from the two metals is allowed to mix. For this reason, it is vital to use some sort of wet dust
collection system with a dry machine.