Embedding Fasteners in Composites

With the world in a movement to save money on fuel costs we must design products to be lighter in weight. To lighten component designs many manufactures are eliminating heavy materials (metals) and moving to composites. This movement has put attention on fastening solutions for these composites. New fasteners and adhesives arrive on the market every month that serve specific purposes. Choosing the correct products can be tough, as the market is vast and material choices are endless. One popular method of construction in these materials is embedding them into the composites during molding.

Embedding fasteners into materials is not a new method of fastening. Since 1907 and the advent of Bakelite there has been embedded fasteners. Threaded inserts were one of the first embedded fasteners and their function was to increase the thread strength in the brittle Bakelite. This concept of making the moldable material stronger in the fastened areas was a big step that opened the door to many new design possibilities.

Currently the leader in the industry of embedded fasteners is bigHead and their custom designs. The basics of what bigHead has done is taking a thread fastener (internal or external) and welding on a large flange with holes. The holes in the flange help the integration of the base material and securing of the fastener. BigHead fasteners can be injection molded around or placed in a mold and fiber-glassed around, the resin will flow through the holes fully engaging it into the base material. Rotational molding is also a great place for bigHead products; they have a new design that encompasses a pipe fitting. This pipe fitting with the flange can be embedded in a rotational mold and replace the need for sandwich style ports on liquid tanks/reservoirs.

There are many more types of embedded fasteners for composites far too many to mention here, but the key idea behind them is to help strengthen the base material by spreading out the load in the weaker material. Point-loading light weight/ brittle materials will fail in a short amount of time so spreading the load out always helps.

Do you have a need for secure, yet discreet fasteners? Consider using embedded fasteners in your product. For more information, contact Bossard at ProvenProductivity@bossard.com.