Mulch films, agricultural applications

This application is very cost-sensitive because of the subsidy structure of the agricultural sector of the EU. The regulations for waste disposal of mulch film require either recycling or adequate treatment (e.g., incineration). If thin mulch films are concerned, the recovery of the film in the field is crop-dependent and difficult. Cleaning of the soil residues is cost-intensive. In this case, it can be more cost-effective to use biodegradable mulch film, which is adapted to the climate and the fruit application. 

The promising market segments of Bionolle in the future are compostable bags and agricultural mulching film applications, where better processability (equivalent to conventional resin) and further cost reduction are required. 

Agricultural mulching film is one of the typical applications for biodegradable plastics. Currently, Bionolle mulching film is commonly used in Japan, and is an important market for us. However, some farmers are anxious about the effects of repeated use of biodegradable plastic on the farm. We, as a manufacturer of Bionolle, need to accumulate knowledge on such usage in the farm. 

Agriculture and horticulture applications include mulching film, covering film and plant pots. 

Realistic uses for Degradable Plastics include those applications where materials are used outdoors for a limited time only and it is not economically desirable to collect the residual materials after use. Examples are agricultural mulch, films and cordage, twine, etc. Another application is that of packaging which is stored and used indoors and discarded outdoors, in other words litter for which manual collection is not practicable. 

At the time of writing, the applications of biodegradable polymers are confined mostly to the field of agriculture, where they are used in products with limited lifetimes, such as mulch films and pellets for the controlled release of herbicides. The synthetic polyesters used in medical applications, principally polylactide and poly(lactide-co-glycolide), while claimed to be biodegradable, are degraded in the body mainly, if not entirely, by chemical hydrolysis. There is little evidence that the hydrolysis of these polyesters of a-hydroxyacids can be catalyzed by hydrolase or depolymerase enzymes. 

Biochemical degradation of plastics is another possible approach. It is realized by addition of organometallic compounds or starch. Examples of applications include the mulch films widely used in agriculture, made of polyethylene or PVC. These films rot within one vegetation period and can be plowed under. 

Otey et al. [61, 68-71] also described blends of starch with synthetic polymers, in which gelatinized starch was used instead of starch granules. The initial films, composed of 90 per cent of starch blended with poly(ethylene-co-acrylic acid) (EAA), were obtained by casting from aqueous dispersions or by dry milling in a rubber mill, followed by a hot roll treatment, but only the cast films attained acceptable characteristics [71]. These materials were intended for application as mulch films for agriculture. 

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