It is easy to cut, may be bent, moulded into different shapes, drawn into a fine pipette and can be joined to itself or to polyethylene tubing. It is resistant to petrol and oil.
REGIONAL TECHNICIANS GROUP
Ideas & Alternatives - EVA tubing
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Ethylene vinyl acetate (EVA) tubing is a rigid walled, flexible plastic
tubing which may be used as a substitute for glass tubing in many applications
in the laboratory.
It is easy to cut, may be bent, moulded into different shapes, drawn into a fine pipette and can be joined to itself or to polyethylene tubing. It is resistant to petrol and oil. |
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One great advantage of this plastic is that it becomes workable at
relatively low temperatures.
Bending - immerse the tubing in boiling water in a metal tray. Use bamboo skewers inserted into the ends of the tubing to make it easier to handle in hot water. When the desired shape is attained, transfer to cold water until the shape becomes rigid. It may be re-heated and re-shaped as often as required. |
| Winding a coil - use a suitable former (eg. plastic pipe.) The
tubing will retain its shape when heated in boiling water and
subsequently cooled in cold water.
The coil is ideal to use as a flexible air-hose (use when inflating "Rocketry" bottles?)
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Joining and welding - to make spatulas first insert a length of dowelling
approximately 2cm shorter than the plastic tubing then gently heat each end
of the plastic in turn until it becomes transparent, squeeze the end of the tube together with pliers and
allow to cool. Unbreakable stirring rods may be similarly made using steel rod as reinforcement instead of dowelling. |
| Joining and welding - gently heat over a low
flame and when the tubing becomes transparent, press the two pieces
together and allow to cool (some practice is necessary to find the most
suitable temperature and pressure to use.)
T-pieces or Y-pieces - first make a hole in the side of a piece of tubing using a hot probe. Gently heat the end of a second piece of tubing and when the tubing becomes transparent, press it gently into the hole made in the first piece. |
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A variety of joiners and adapters can be made by heating and drawing-down the tubing to the required size. Ends can be flared by heating in boiling water and flared with a suitable sized pencil or piece of dowelling which has been tapered. |
The tubing is not available in small quantities from the manufacturer but Nathan Wende (Girrawheen S.H.S.) has purchased two large rolls, in two different sizes, which may now be obtained directly from Nathan or through your local Regional Technician.
The smaller diameter tubing will fit through most 1- and 2-holed rubber stoppers and the two sizes of tubing will fit tightly together making it possible to produce a wide range of connectors.
It must be remembered though that the tubing cannot be used for delivery tubes involving hot substances, or washed in a dishwasher, without losing its pre-formed shape.
