Industries and GRP pipes manufacturers agree that FRPs are wonderful materials to intend a range of products. The specific properties offered by GRPs and FRPs give them an advantage over conventional materials yet the products made of these polymeric composites pose serious environmental issues. FRP material is not easy to recycle due to its multiphase nature.
Though many recycling technologies have been introduced, but nothing has proved economically viable. In most cases, the price of raw material generated by recycling of composites costs higher than the virgin reinforced materials and fillers.
Global industries including electronics, transportation and automotive have contributed significantly to the promotion of FRPs materials. Although, market has other types of thermoset composites, but sheet and bulk moulding compounds take the largest portion of thermoset composite waste as they are used for high-volume applications.
Take an instance of automotive industry, which has steadily increased its use of BMCs and SMCs to produce lighter, more fuel-efficient automobiles.
FRPs have multiphase nature as they contain three or multiple components. Recycling of thermoset FRPs brings tough challenge as once the thermoset matrix molecules are cross-linked, they are impossible to reform or melt. Thermoplastics are different and can be recycled. Moreover, the value of the material constituents of GRP availed from recycling is low. This, there is little profit in recycling.
Manufacturers categorize the recycling technology into four classes:
- Energy recovery
- Thermal breakdown of the matrix
- Size reduction
- Chemical breakdown of the matrix
Pyrolysis and fluidized beds are two thermal decomposition techniques used by manufacturers to recycle thermoset composites. Each of these techniques removes the resin by volatizing it with heat. The end-products are usually gases and liquids from the resin, which are repurposed as fuels and extenders in other materials. The issue with these techniques is the high temperatures required to achieve results either degrade the glass fiber properties or exceed the value of products extracted.
Size reduction is the only successful method used by industries to make useful recyclable products from BMC and SMC waste. The grinding method used by distinct recyclers includes individual technologies, but every methodology includes a series of separation steps and size reduction. The ground recycled product is mixed with virgin composites to form a new FRP or GRP material.
You now know the methods used by GRP pipes manufacturers for recycling the FRP/GRP waste. If you want more information, write in comments.