Direct Long Fiber Thermoplastics (Compression Molding Method)

Long fiber thermoplastic molding is a newer technology where thermoplastic material is directly compounded with long glass fibers (roving) and then molded in one operation.
Processing technologies for manufacturing LFT parts strongly influence the final part properties. Different methods of manufacturing LFT parts can be classified into direct and indirect categories.
In LFT-D (direct LFT), thermoplastic resin, additives and fiberglass roving are mixed, impregnated in a twin-screw extruder to form the compound, which is directly processed by injection or compression molding to final products. The advantage of D-LFT is the ability to control the length of the fiberglass being mixed into the thermoplastic pellets via an extruder. The process enables control of the compound properties, therefore the part, with high consistency.
In compression molding method the material is not subjected to the same high levels of stress as in injection molding, which helps to maintain fiber length. This is critical because the mechanical properties of fiber reinforced thermoplastics are strongly dependent on the fiber length.
The production of LFT by direct and compression molding method is superior to other methods due to the possibility of changing the raw materials and modifying polymer and process parameters, which is important for automotive applications.
This gives the manufacturer the ability to enhance the properties of the resin as required for the application by adding fillers, fire retardants and additives, while also significantly reducing material costs.

Advantages

– Increase stiffness-to-weight ratio compared to similar steel products
– Ability to control glass fiber length and percentage
– Possibility of changing the raw materials and modifying polymer and process parameters
– High chemical resistance
– Appropriate mechanical properties
– Appropriate price

Applications

– Automotive industries: (Cooling pack 206, Bumper beam, Underbody shields …)