Press-Platen scraper
DEMCO SUPER SCRAPER
- Demco Super Platen scaper with new heads
- Introduced into the plywood industry in 1990
- There are presently over 105 units in operation in the plywood, MDF, OSB and particleboard industries
- Presently, in the plywood industry, units are being used in plants that produce sheathing, sanded plywood, hardwood overlays and paper overlay products
- Many other industries have had demonstrations in their presses with very good success
- This unit can be successfully used in any flat surface press application
- It was not designed to be used on embossed hot plates
- Here are a few of the things people have discovered with the DEMCO Super Scraper:
- It will show up a platen that is warped or bowed.
- It is not intended to be a machine tool. It will not resurface old platens to be used for paper overlay products, as an example. But, it will improve surface finish by removing dings and small ridges.
- One user had a temperature gauge that showed a platen surface temperature. A reading was taken before we started scraping. Approximately .050" of buildup was then removed. The next surface reading was 75 deg. F. higher after the buildup was removed .
- The aluminum bronze blades have been very successful in removing tape from platens without scarring the platen surface.
- How long do the blades last? Please be reminded that the steel blades have (4)four scraping edges and the aluminum bronze only have (2) two. As to blade life, one user is replacing or resharpening monthly, while most have never changed or rotated them. Every application or condition is different.
- A 4' x 8' opening takes an average of 3 to 5 minutes to scrape. A 4' x 8' x 30 opening press takes an average of 4 hours to scrape by one person. A 5' x 24' x 16 opening particleboard press is being scraped in approximately 4 hours.
- The control unit is furnished with casters,so it can be easily pushed around. It is also furnished with a frame so the head, jacks, hose assembly and remote control pendant can be stored on the control unit. The jacks are not required for the particleboard, MDF or OSB presses.
- If the press can be cooled down, the buildup becomes more brittle and comes off easier. We have worked in presses over 400" F., but it can shorten the life of the actuator airbags.
- TO OPERATE THE MACHINE, it requires a 3/4" air supply from your plant air system at a minimum, if possible, of 80 PSI and a 110 Volt 60 HZ AC extension cord.
- Standard Scraper heads are available for 23/4" to 41/2" daylights and ranging from 24" to 80" in length. For any special applications, we will build to suit, let us hear from you.
- Various scraper blades can be mounted in the head clamps, (8) eight in total, to handle very rough surfaces to paper overlay (high grade) surfaces and any combination you may have.
- Examples:
- Steel blades are used for the rough surfaces to remove build-up, and any high spots in the platen surface that would cause dents in your panel surface. These blades will always try to make your platen surface as flat as possible, even to the point of removing the machined ridges left by some types of platen surfacing processes.
- Aluminum bronze blades are used for the high grade surfaces so no metal is removed from the platen surface.
- Other materials and configurations are available to accommodate other applications.
- Some people are sharpening their own blades once or twice, but generally find buying new ones is cheaper.
- The scraper head control unit houses a PLC, solenoid air valves, regulators, vacuum pump and a hand held remote control for head functions, forward, reverse, stop and left/right steering plus jack operation for plywood units.
- The scraper head itself consists of(4) four aluminum machined channels with a scraper blade on each leg of each channel. Two channels are set back to back with an air bag between them so they can scrape the top and bottom surfaces at the same time. There are two sets of these back to back channel units with two air bags between them which create the forward/reverse movement and steering. There are (4) four air hoses that connect the control unit to the head to operate the (4) four air bags in the head.
- The operation sequence of the head is as follows :
- One set of the channels becomes the scraping section - one set is the clamp section. When reversing, the sets of channel sections reverse their operating function. 15 to 30 PSI is applied to the scraping section at all times during operation. The vacuum pump has pulled the clamp section as close to the scraping section as possible. Air system pressure, approximately 80 PSI, is then applied to the clamp section. Air system pressure is then applied to one or both airbags between the scraping and clamp sections to create a forward motion at one or both ends. This is how a straight or steering motion is created. The clamp section is deflated as the bags between sections are deflated. The vacuum pump again draws the clamp section to the scraping section and the process begins all over again.