unting on gear unit side left G Protective cover B4-CH5A Bevel-helical gear box B4

Flender/Flender Gear Units/Bevel-helical gear box B4

terial. 3.3.1 Bags The most widely used consumer-unit package is the bag. It is inexpensive, is easily lled and closed, and is available in many sizes and many materials. It provides less protection from physical damage than most other packages. 3.3.2 Plastic-Film Bags Numerous transparent and translucent lms of various compositions are available commer- cially, and some of them at lower cost than kraft paper, cotton cloth, or burlap. Prefabri- cated bags are available from many manufacturers and may also be fabricated at the users premises by machines that will form and heat-seal bags from rolls of at lm. The advan-tages of plastic-lm bags are () good visibility of the packaged product, () limited perme-ability to water vapor and reduced moisture loss from the product, and () strength andtear resistance of 1.0 to 1.5 mil lm. 5 Smith et al. 3.3.3 Mesh Bags The ultimate in ventilation of contents is achieved in the mesh bag. The netting with openings between strands of 3 to 6 mm allows free movement of air to and from theinterior of the bag. Mesh bags are fabricated from several materials, the most common of which are ne plastic strands, cotton thread, and twisted strands of processed paper. The important advantages of mesh bags are () excellent ventilation for heat exchangeduring precooling, () avoidance of high relative humidity in the bag for commoditiesand situations in which high relative humidity is undesirable, () good visibility of product,and () easy closure. Mesh bags are widely used for origin prepackaging of oranges,because the fruit cools faster in mesh bags than in plastic lm, and the hazard of fruit decay during prolonged marketing period is somewhat lower in mesh than in lm. Apples are less commonly packed in mesh bags because they are usually cooled before prepackag-ing and the possibility of decay during marketing is lower for apples than for oranges. 3.3.4 Shrink-Film WrapsFilms of number of types can be given heat-shrink characteristics by stret