Corriflute or correx is a very strong construction material but it takes special tools to work it ie. to punch and cut accurately. It is made from two layers of very thin plastic sheet with corrugations or ribs in between holding the sheets together.
The thin blue strips have been cut using a craft knife and safety rule on a cutting mat prior to the lesson. It is tough to cut and their are major safety issues even up to year 6. If precut and punched strips are used then this technique of bridge building can be used with year 2 upwards.
The strips are great to work with and can be held together by using small elastic bands at the ends. They can also be hot glued and if punched can be ‘click riveted’ together using small plastic rivets which are pushed in by hand (see below).
Simple card templates or guides can be used when positioning holes accurately in the ends of the strips. The holes are made by a punch as shown.
A great way to join the strips together in a structure is to use wooden dowels as with the paper roll tubes.
The great advantage of wooden dowels as the method of fastening is that the structures can easily be modified and designs changed without any great loss that would occur if the structure was glued.
Corriflute strip is brilliant for making robust structures and mechanisms such as bridges or fairground rides which move using winding mechanisms, pulleys, electric motors or syringes containing air or water.
Making corriflute structures takes more preparation than other types of construction method and is more expensive than the simpler paper and card methods.
There is a special type of fastener called a ‘click rivet’ which provides an alternative method of fastening the corriflute strips together. The rivets are in two parts - the ‘rivet’ itself which is like a nail with a head but without a point, and the retainer which is like a ‘nut’ which is a tight push fit onto the end of the rivet.
A hole has to be made through the strips first and this is best made using a thin pointed wooden dowel. If a conventional metal hole punch is used the holes tend to be too big and the joints tend to be slack.