Method and apparatus to determine composite prepreg tack

Abstract

A method and apparatus for determining whether the tack of a composite prepreg is within an appropriate range to adhere to a substrate when joined under predetermined conditions. The resulting tack measurement can be used as a measurement of quality control for prepreg's used in automated tape-laying machines, hand layup operations, or as a control variable in prepreg development. An embodiment of an apparatus of the present invention has the ability to simulate the prepreg layup of an automated tape-laying machine. This includes the ability to adjust the rate at which the prepreg is laid up, the force used layup the prepreg, the durometer of the material from which the application roller is formed, and the diameter of the application roller used to layup the prepreg. One embodiment of the apparatus includes a table with a movable platform capable of joining two strips of prepreg under conditions similar to an automated tape-laying machine by moving the prepreg between the platform and the application roller. The table is connected to a controller that adjusts the rate at which the prepreg is moved into contact with the application roller. The joined strips of prepreg are then separated and a value of tack, such as the average force or energy required to separate the strips is measured. In another embodiment of the present invention, contrast analysis is used to determine the adhesive contact area between a strip of prepreg and a visually transparent substrate. The percent adhesive contact area is then used as a measurement of prepreg tack.

Dependencies are inferred from the claim text.