Biomass Plastic Material Technology
Ricoh was quick to focus attention on biomass plastics as a material that contributes to preventing global warming while reducing the consumption of petroleum, an exhaustible resource. We will accumulate technologies and apply them to product materials.
Advantages and issues in the use of biomass plastics
Biomass plastics use the biomass resources of regenerable biological origin. The one being in practical use now is based on plant-derived material. The plastics are high-polymer materials whose raw materials are the starch, sugar, or cellulose contained in plants. An example is polylactic acid, the chemically-synthesized lactic acid fermented from starch. Even if CO2 is ejected when polylactic acid is incinerated, it is a component absorbed by photosynthesis when the plant used as material grows; it does not increase CO2 in atmospheric air (carbon-neutral). Therefore, it is an environmentally-friendly material that does not contribute to global warming (Figure 1). Further, this material is as strong and rigid as polystyrene. However, to be used as a material for durable goods, polylactic acid has issues related to heat resistance and impact resistance as well as the need to retard flame; it must provide non-flammability of parts for electric and electronic devices. Further, it must be amendable to low injection molding.
At Ricoh, with the aim of resolving these issues and paving the way to fully adopt polylactic acid, we are developing a materials technology for applying polylactic acid fermented from non edible materials. Examples include timber from forest thinning and waste wood for use in durable parts. There is also a molding technique suited to mass production that achieves economic efficiency.
At Ricoh, with the aim of resolving these issues and paving the way to fully adopt polylactic acid, we are developing a materials technology for applying polylactic acid fermented from non edible materials. Examples include timber from forest thinning and waste wood for use in durable parts. There is also a molding technique suited to mass production that achieves economic efficiency.
 |
| Figure 1: Circulation of biomass plastics |
Issues toward expanding use of biomass plastics and Ricoh's approach
1. Issues in expanding applications in multifunction copiers
A multifunction copier uses about 20% to 30% in ratio by weight of resin components. Resin component applications are wide ranged. Interior components include interior covers and paper feed trays, and exterior components include covers. There are also functional components like the fusing unit that require high heat resistance and those like the optical unit requiring high dimensional precision. The issues demanded for each differ (figure 2). Exterior components, which use much resin, must be fire retardant (non-flammable). Ricoh will solve various issues responding to applications, and will extend the application range. |
| Figure 2: Proportion of resin adopted for multifunction copiers by application and properties required by the application |
2. Issues in improving biomass content
There are three major issues with polylactic acid, which is a crystalline polyester.- Crystallinity (degree of crystallization) influences heat resistance and impact resistance.
- Crystallization speed influences molding cycle time.
- It is hard to secure fire retardancy with polyester.
Until now, we have overcome these issues by blending a certain quantity of petroleum-derived plastics. Therefore, it was difficult to increase biomass content (*1) and the limit was at most about 50%. To improve, Ricoh has developed new additives jointly with a materials supplier. This was done to control crystallinity, without mixing petroleum-derived plastics, while ensuring heat resistance and impact resistance. The result is high biomass content (about 70%), which is the best in the industry (as of May, 2012) (Figure 3). Further, this can be formed as fast as with the conventional petroleum-derived plastic material, and it can be processed in mass. We will continue to challenge technology development to improve biomass content and to reduce environmental impact.
(*1) Biomass content: The proportion of biomass resources used as the raw material of a plastic component.
 | |
| (a) Conventional biomass plastics Biomass content (about 50%) |
(b) New biomass plastics Biomass content (about 70%) |
| Figure 3: Biomass content compared with conventional and new method | |
Ricoh's direction in applying biomass plastic as multifunction copier components
Ricoh adopted biomass plastics of 50% biomass content the first time in 2005 for a part of the multifunction copier housing. The company then increased the biomass content to about 70% and included it as a manual pocket in October 2008 (Figure 4).
 |
 |
| (a) The imagio MP C2200 manual pocket | (b) Installation position on imagio MP C2200 |
| Figure 4: A part mounted on the imagio MP C2200 (October, 2008, sold in Japan) | |
From now Ricoh will develop technology for higher biomass content and increased application range towards our environmental target in the fiscal year 2020 -- "25% reduction (ratio against the fiscal year 2007) of newly loaded resource amount." We will also expand the amount of biomass plastics used (Figure 5).
 |
| Figure 5: Development image of biomass plastics |
