Wet Grinding System
DJH Designs’ Wet Grinding System is a complete turnkey solution to grinding and finishing your coater and squeegee rollers. It achieves a far superior roll concentricity thanks to our unique bearing cradle design to grind the rolls on their bearings. Grinding with the bearings ensures the roll concentricity is true to the bearing journals so the rolls run true when installed on the line.
The system is comprised of the following:
FEATURES AND BENEFITS
ADVANTAGES OF WET GRINDING VS DRY GRINDING
Superior Roll concentricity
DJH Designs Wet Grinding System utilizes our unique bearing cradle design to grind your rolls on their bearings. This process results in far superior roll concentricity than those systems that grind rolls on the shaft centers. Grinding with the bearings ensures the roll concentricity is true to the bearing journals so your rolls run true when installed on the line.
Dry grinding can typically take up to 2 hours depending on the roll type and finish required. It could take up to 4 hours to complete the grinding roll. The Typical wet grinding cycle can be done in as little as 15 minutes (excluding final sanding/polishing). It is not uncommon to be able to completely grind and polish a roll in as little as 30 minutes.
Superior Roll finish with a single pass grinding cycle
Dry grinding causes a significant heat buildup on the surface of the roll due to the friction of the grinding wheel in contact with the roll surface. This friction buildup not only causes surface distortions but can also can burn or damage the roll surface if too heavy a cut is attempted. Surface friction from dry grinding also exasperates a phenomenon called the bow wave effect. The bow wave effect is a pressure wave that builds up in the surface of the roll ahead of the leading edge of the grinding wheel, exactly the same way a boat creates a bow wave in the water ahead of its prow. As the depth of cut increases the amount of friction also increases and the coating becomes softer, this amplifies the bow wave effect. The grinding wheel also has a tendency to ride up on the wave and as it rollercoasters over the pressure wave if the feed rate is too high you end up with micro ridges in the roll surface. Wet grinding significantly reduces the bow wave effect by keeping the surface of the roll well cooled and lubricated so that you get a very clean cutting action on the face of the roll without the problem of ridges.
Low durometer rolls can be ground without any modification to the grinding process
Dry grinding of low durometer rolls requires a significant change in the approach to grinding rolls. It requires lower feed rates and greater reduction in the depth of ach pass. This greatly increases the cycle time over wet grinding. With wet grinding there is no need to significantly alter the grinding process.
Dry grinding requires the use of high-volume dust extractors to control the grinding dust coming off the roll. This dust is not only hazardous to the operator and the environment, it possesses a significant fire hazard. With the Wet Grinding System there is no dust to contend with, the cutting fluid draws the grindings away as a slurry that is pumped into a filter bed and disposed of automatically into to hopper. Disposal is easy and can be included in your normal waste stream.
One of the features that make the Rubberhog wheels your best choice for elastomer grinding is the wide selection of coating types and tooth sizes. This broad coating choice assures that we can offer a wide selection of grinding wheels to meet your specific requirements. The carbide teeth are positioned to provide fast penetration into the material and unrestricted flow of debris away from the wheel. This provides a free-cutting action, drastically reducing the time required for grinding. In conjunction the finish sanding attachment provides the ability to finish rolls to a high degree of ultra-smooth roll finishes.
The combined selection of the grinding wheel tooth and finish pass paper grit ensure an ultra-smooth roll finish for the ultimate in coating finish.
Wheel type and finish paper selection can be tailored to meet the specific requirements of the customers application.
As unfiltered liquid flows onto the filter media, it passes through the blanket and deposits solids on the media surface (thus forming an additional filtering stage). When the rate of liquid flow through the filter media is appreciably slowed by the accumulation of waste, the level of standing liquid rises and actuates at the level control. The motor driven conveyor belt is advanced, dumping the waste off the end of the unit into your bin and bringing a section of fresh media into position under the liquid flow.
The float control senses when the liquid flow has resumed its proper rate, and controls media advance accordingly.
Typical Grinding System
**Subject to change depending on options.
1) System is sized as per customer supplied roll drawings and bearing specifications.
2) Customer to advise if sleeve assembly is used with the bearing or if the bearing fit directly in their bearing blocks (no sleeve adapter).
3) Rolls with cartridge type bearings can only be ground on centers unless cartridge bearing is removed and regular bearings are installed for the grinding process. Optional cradle adaptors are available for other bearing sizes if required.