Cocoon drying

Electricity use in cocoon drying 1 kWh/kg fresh cocoon (Singh, 2011)... 

Energy requirements for cocoon drying could be reduced by promoting solar dryers. Compared to electric driers, dryers based on solar energy have been shown to reduce electricity consumption ten-fold (Singh, 2011). 

Singh, P.L., 2011. Silk cocoon drying in forced convection t5fpe solar dryer. Apphed Energy 88, 1720-1726. 

Films or membranes of silkworm silk have been produced by air-drying aqueous solutions prepared from the concentrated salts, followed by dialysis (11,28). The films, which are water soluble, generally contain silk in the silk I conformation with a significant content of random coil. Many different treatments have been used to modify these films to decrease their water solubiUty by converting silk I to silk II in a process found usehil for enzyme entrapment (28). Silk membranes have also been cast from fibroin solutions and characterized for permeation properties. Oxygen and water vapor transmission rates were dependent on the exposure conditions to methanol to faciUtate the conversion to silk II (29). Thin monolayer films have been formed from solubilized silkworm silk using Langmuir techniques to faciUtate stmctural characterization of the protein (30). ResolubiLized silkworm cocoon silk has been spun into fibers (31), as have recombinant silkworm silks (32). 

OLEUM PER ELIXATIONEM EXTRACTUM — is that which is extracted by cocoon, which can be performed either by boiling in moisture, or by a dry flame. 

Lungfish live in areas with temporary water bodies, such as shallow swamps, the stagnant backwaters of river courses, and small creeks. These areas are prone to dry out during the dry season. As the water recedes, lungfish burrow into the mud, forming a hollow at the end of the tunnel. The lungfish curl up, tail over head, keeping the nostrils clear of dust and dirt, and secrete a mucous cocoon. 

Aphid midge Aphidoletes aphidimyza Over 60 species of aphids. Apply 250 cocoons in a small garden or greenhouse or use 3-5 cocoons per plant repeat in 2 weeks use 5-20 cocoons per fruit tree. Reliable except in dry, windy areas not suitable for melon aphid control. 

For drying of silk cocoons, laboratory-scale testing in the People s Republic of China has proven the enhancanent in quality of the silk produced (e.g., brightness, strength of fiber, etc.) in steam drying at a temperature of around dS C. For certain food or vegetable products, the yielded porous structure of the product dried in superheated steam (due to evolution of steam within the product that enhances porosity) is a desirable characteristic. This decreases the bulk density of... 

To recover the silk, the pupae are killed with steam or hot air. By immersing the cocoons in hot water, the silk glue is softened. Rotating brushes catch the end of the silk fiber and 4-10 of the threads are wound together onto a reel and dried. Of the 3 000-4 000 m of thread per cocoon, only about 90 m can be unwound. The outer and inner layers are too impure and are used along with damaged cocoons in schappe spinning. 

Akao et al. (1982) reported on a commercial steam-drying/deodorization plant to process soy sauce cakes as feedstock. An agitated trough steam dryer (1.5 tons/h dry product capacity) was used. Deodorization commenced at moisture levels below 4% db and a temperature of 135°C. The oils and fats distilling from the cake resulted in deodorization of the product. Indeed, the fats and oils were used as auxiliary fuels for the process. Concurrent steam drying and deodorization of rice bran, fish meal, and silk cocoons were also reported by Akao (1983). In these products, the odor is due to oxidation of lipids. He also showed that the quality of green tea and vegetables dried in steam (e.g., color, smell, etc.) was acceptable. 

Products that may require oxidation reactions (e.g., browning of foods) to develop desired quality parameters cannot be dried in superheated steam. However, it may be possible to consider a two-stage drying process (e.g., steam drying followed by air drying). For drying of silk cocoons, for example, such a process appears to yield a higher quality product. 

Silkworms are cultivated and fed with mulberry leaves. Some of these eggs are hatched by artificial means such as an incubator, and in the olden times, the people carried it close to their bodies so that it would remain warm. Silkworms that feed on smaller, domestic tree leaves produce the finer silk, while the coarser silk is produced by silkworms that have fed on oak leaves. From the time they hatch to the time they start to spin cocoons, they are very carefully tended to. Noise is believed to affect the process, thus the cultivators try not to startle the silkworms. Their cocoons are spun from the tops of loose straw. It will be completed in two to three days time. The cultivators then gather the cocoons and the chrysales are killed by heating and drying the cocoons. In the olden days, they were packed with leaves and salt in ajar, and tiien buried in the ground, or else other insects might bite holes in it. Modem machines and modem methods can be used to produce silk but the old-fashioned hand-reels and looms can also produce equally beautiful silk [55, 56]. 

In industrial production, the silkworm is grown on trays, and the larvae are fed with freshly harvested mulberry tree leaves. Thirty grams of eggs (40000-60000) consume one ton of leaves in the 35 days of their life time. The pupae contained in the cocoons are killed by steam. In the filature (reeling plant), the cocoons are treated with hot water, whereby they are opened to show reelable thread ends. The continuous filaments (up to 3000 m long) are wound onto a hank, which is finally dried. Wastes are used either as spun yams (schappe) or bourette silk, which is made from the wastes of schappe spinning. Dead pupae are used as fish feed. 

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