Roll wrapping

Hose may be hand built using a three roll wrapping machine. The centres of the three rolls form an equilateral triangle. The hose during construction sits on the junction between the two lower rollers and pressure is exerted to consolidate the composite by the upper movable roller. An extruded inner liner, after fitting to a solid inner mandrel, is placed into the machine between the rollers and then the various layers of rubber coated or resorcinol-formaldehyde-latex treated, fabric are applied in a spiral form, with overlap. Once the reinforcement layers have been added the cover rubber is applied and a cloth, usually nylon, is spirally wrapped around the constructed hose using the roller system. The hose is now ready for vulcanisation. 

Fold—overwrapping without sealing, fold over, fold down, grocer s fold, roll wrap, bread wrap, etc. Note dead fold characteristic of soft foil (see BS 1133) and overwrapping, plus seal—i.e. heat, adhesive, etc. 

By arrangement, e.g. in blisters, or columnar in the case of roll wrapped tablets etc. 

Fig. 8.10 Conventional roll wrapping machine (source Voith).

Plateout Poor chill roll contact Increase chill roll wrap-around Adjust air knife... 

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