From Biocides in Plastics

The microorganisms of importance fall into three broad groups (Figure 2). Viruses may also be mentioned although these are less well documented as an issue for growth in or on plastics.

Figure 2: The Three different types of microrganisms

2.1 Bacteria

Can degrade plastics by utilising raw materials as a food source, potentially causing surface staining (Figure 3), pitting and malodours. Plastic material can also provide a surface for the growth and proliferation of pathogenic organisms.

Figure 3: Staining of PVC film

2.2 Fungi

Moulds can degrade plastics and grow within them (Figure 4), reducing structural strength, conductivity or other physical properties. They can cause unsightly and aesthetically unpleasant growth on the surface and potentially enable the growth of some fungi that produce harmful mycotoxins.

Figure 4: Microscopic view of Penicillium sp. growing within a matrix

Yeast can also stain and cause malodours on plastics.

2.3 Algae

Although they can be unsightly with green, brown or black discoloration of surfaces, they themselves cause no damage to plastics, as they do not use them as a nutrient source. They can however trap water, encouraging fungal growth (Figure 5) and physical 'freeze and thaw' effects.

Figure 5: Fungal colonies growing on roof felt

Products & Services
Architectural Coatings
Architectural coatings include paints, sealers, and specialty coatings for floors, roofs, walls, ceilings, decks, pavement, walkways, concrete surfaces, and other building and construction applications.
Sorting Equipment
Sorting equipment is used to separate dissimilar items into predetermined groupings as part of an automated process.
Water Disinfection Systems
Water disinfection systems treat water to inactivate, destroy, and/or remove pathogenic bacteria, viruses, protozoa, and other parasites. Common methods include chlorination and alternative disinfectants.
Biological Materials
Biological materials are biocompatible materials, natural or man-made, that comprise a whole or a part of a living structure or biomedical device that performs, augments, or replaces a natural function

Topics of Interest

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