PTFE adhesive molds; a pleasure to work with!
The milled PTFE plates with a maximum thickness of 20 mm are suitable for simultaneously positioning and curing 10 test specimens of 100 * 25 mm with an overlap of 12.5 mm (shear test). Adhesive molds for specimens of 275 mm for the roller-peel test will follow soon. Next week (week 12) the temperature/dimensional stability will be tested during the practical training of the European Adhesive Bonder course. This will test whether the plates can withstand curing of, for example, 1K Epoxy in the oven at 150 degrees C.
Why a new design?
Until now, aluminum adhesive molds that are adjustable in length and width have always been used. To prevent the specimens from becoming stuck to the aluminum material during curing, the molds were regularly coated with a PTFE coating. However, this only works partially, which is why it was always quite a hassle to remove the test specimens from the mold and then clean the mold of adhesive. When removing a test specimen with some force, the adhesive bond was also mechanically stressed considerably. This has a negative effect on the final measurement value.
Due to the complexity of the aluminum adhesive molds, they are also unnecessarily expensive for the actual purpose. The PTFE material is admittedly costly in itself, but the production method and simple design of the molds make them considerably cheaper than the aluminum adhesive molds.
No spring loading but steel weights To exert some pressure on the adhesive bond during curing, spring loading was previously used. With the arrival of the new PTFE molds, this spring loading has been replaced by loose weights of 20*20*100 mm. To prevent the weights from sticking to the test specimens, a thin PTFE foil is placed between them.
Where to buy?
All mentioned materials are available from stock and can be ordered via Makiba's web shop. If you have questions or are considering purchasing larger quantities, please contact us. We are happy to assist you.