Packaging materials range

Packaging. Because of the extremely broad demands on the mechanical properties of packaging materials, the entire range of ceUular polymers from rigid to flexible is used in this appHcation. The most important considerations are mechanical properties, cost, ease of appHcation or fabrication, moisture susceptibUity, thermal conductivity, and aesthetic appeal. 

Nearly all the expanded polystyrene that is not used for thermal insulation is used for packaging. Uses range from individually designed box interiors for packing delicate equipment such as cameras and electronic equipment, thermoformed egg-boxes to individual beads (which may be up to 5 cm long and about 1 cm in diameter) for use as a loose fill material. There is also some use of thin-wall containers for short-term packaging and conveying of hot food from... 

Common packaging materials are a potential source of aggressive substance s, and careful selection is recommended to avoid surface deterioration. Where paper is in contact with aluminium, the chloride content should be below 0-05 7o, sulphate content below 0-25 7o, copper content below 0-01% and the pH of aqueous extracts in the range pH 5-5-7-5, in order to avoid corrosion in damp conditions. Papers and felts used in building applications should also conform to this specification as a minimum requirement and be of the highest quality, since metallic copper found in materials of inferior origin can result in severe local galvanic attack of aluminium. 

There is no precise definition for the frequently used term application fastness of a pigment. It usually refers to the behavior exhibited by a finished product used in accordance with the specifications. The term may thus refer to a print, a coated object, or a plastic product, and the list of features ranges from properties such as lightfastness and weatherfastness to migration fastness and fastness to solvents. In this context, there is a certain amount of emphasis on features which play a role in connection with packaging materials and packed articles. 

The range of packaging materials covered in this chapter includes those for still and carbonated products, some of which can be cold-filled and others that need to be heat-treated. Heat treatment can either be within the package or by... 

A tremendous range and variety of chemicals are used to make modem packaging materials. The European inventory list of chemicals used to make plastics intended for food contact numbered more than 1500 listed substances and inventory lists of a similar length exist for chemicals used to make paper, can coatings, inks and adhesives. The chemicals on the plastics inventory list mn literally from A (acetic acid) to X (xylene) with more than 1500 chemicals in between. Substances needed to make effective plastics packaging materials include ... 

In conclusion it must be emphasized here that the values of partition coefficients of permeating substances cover a range of more than 9 orders of magnitude (10 2 to 107) dependent on their structure and the polarity of the filled product and packaging material (e.g. polyolefins/water) and this is only for a single polymer (e.g. LDPE). This means that in practice, the importance of the partition coefficient in the permeation of organic compounds is often not given the attention it deserves. 

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