Ricoh has developed an environmentally-friendly technology that removes residue without using solvents or water. Instead,
small thin films are air-blasted onto the object to be cleaned to remove the residue. This technology is applied to clean
jigs used in the manufacturing process and parts during the recycling of products.
This technology is based on the principle of using airflow to blast thin resin films—each a few millimeters
square—onto the object to be cleaned and removing the residue with their impact or contact (Figure 1). The thin and lightweight
film, which does not damage the object to be cleaned, effectively removes residue at the edges that cannot be removed by
high-speed airflow alone.
This process uses neither solvent nor water, and it also minimizes the amount of material used for the thin and lightweight
film. Its capacity for removing residue does not diminish after repeated use, so the resin films can be used continuously
without being replaced. Only residue removed from the object is discharged, with the resin films used repeatedly through
continuous circulation (Figure 2). These properties make it possible to reduce both environmental impact and operational
cost.
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Figure 1: Removing residue by resin films |
Figure 2: Separation and discharge of residue |
Washing Adhered Residue |
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Drastic Improvement of Washing in Manufacturing Process
In order to recycle our products, such as copiers or printers, Ricoh has been researching and developing
dry washing technology that eliminates waste liquid. Ricoh has applied this technology to the washing of jigs (pallets) used
in the automated soldering process. Although pallets are generally cleaned with solvents, we have achieved solvent-free washing
with this technology.
As shown in Figure3, jigs called pallets are used in the automated soldering process (flow soldering machine) to protect
already-soldered parts from heat. In this soldering process, liquid flux is applied to eliminate the oxidized layer of the
joining surface, but the flux gets laminated and adheres to pallets through repetitive use. The flux remaining on pallets
must be cleaned off periodically.
Figure 3: Cross-section view of a pallet used in the automated soldering process
Washing solder flux without solvent
Ricoh has been further developing dry washing technology, which was originally developed to remove
toner from parts or components, and, while doing so, the company found a way to remove even adhered flux without using solvent
cleaner.
Pieces of film can be easily separated from the removed residue (flux powder) because of the difference in the sizes between
the film and the flux powder. Only the flux powder is collected by a dust collector and the films are used repeatedly through
continuous circulation (Figure 4).
Figure 4: Dry washing mechanism for removing adhered flux
You can watch a video clip of the process of dry-washing a pallet.
Movie 1: Removing adhered flux by a dry washing method
Figure 5 shows the pallet before/after dry washing for 2 minutes.
(a) Pallet with adhered flux |
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(b) Pallet after dry washing |
Figure 5: Pallets before/after dry washing
Effect of the Reduction of Environmental Impact
This new method can reduce both environmental impact and washing costs by up to one tenth compared
with the conventional method using solvent (calculated by Ricoh). Washing time (process lead time) has also reduced from
more than 2 hours to less than 5 minutes.
Figure 6: Comparison between the conventional and new processes
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Conventional process |
New process |
| Process time |
More than 2 hours |
3 to 5 min. |
Environmental impact
(waste liquid) |
0.1 to 0.8L / pallet |
0 (*1) |
Environmental impact
(CO2 emissions) |
0.2 to 2kg / pallet (*2) |
0.1 to 0.2kg / pallet (*3) |
(*1)The removed residue (flux powder) is collected by a dust collector.
(*2)Solvent production and incineration
(*3)Consumables, electrical power, washing equipment production, etc.
The range of values is attributed to the different cleaning methods, production scales and pallet sizes of the production
sites.
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Table 1: Comparison between the conventional and new processes
This method comes into practical use for the washing of pallets used in the automated soldering process
at Ricoh Group domestic and overseas production sites.
Washing Powdery Residue |
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Drastic Improvement of Washing Process for Product Recycling
Product recycling is a vital environmental protection activity for reducing the environmental impact.
Regardless of how much effort we devote to recycling resources, it is not meaningful if the recycling process generates a
heavy environmental impact. The washing process accounts for the highest proportion of the recycling process of copiers and
printers (Figure 7). Ricoh has developed technology to improve this process.
Figure 7: Recycling process Washing by the dry washing method
Figure 8 is a dry washing machine for removing toner from parts during the recycling of products.
You can watch a video clip of the washing of parts.
Figure 8: Dry washing machine for parts |
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Movie 2: Removing toner from parts to be recycled |
Effect of the Reduction of Environmental Impact
Water has been used in the conventional washing process to reclaim parts and components covered with
toner. This process requires time and energy for dewatering and drying, and moreover, wastewater generates an environmental
impact and processing costs.
Ricoh has developed dry washing technology that does not require dewatering and drying. As a result, a process that used
to take more than 1 hour has been shortened to about 1 minute, and wastewater has been reduced by 2.4 tons per month (Figure
9 and Table 2).
Figure 9: Comparison between the conventional and new processes
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conventional wet method |
dry washing method |
| numbers of processes |
8 (disassembly, vacuum cleaning, ultrasonic washing, rinsing,
dewatering, drying, finishing, inspection) |
4 (disassembly, dry washing,finishing, inspection) |
| washing time |
10 min. |
1 min. |
| drying time |
1 hour |
0 min. |
| amount of wastewater |
300ml/unit |
0 |
Table 2: Comparison between the conventional and new processes
This washing method is applied to the washing process for cartridges of multi-function printers at
manufacturing sites worldwide.
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