A new breed of ultra-high load pultrusion machines.
Newer resins, emerging applications that require a higher than normal Vf, and increased demand for multi-cavity production necessitate a new breed of machine that can handle the increased pull loads.
PulFORCE Advancements in Design
CHALLENGE:
Build a pultrusion machine capable of 50 tons of pulling and clamping force in a compact design.
“Machine design must continue to evolve to accommodate modern applications and increasing demand for higher speeds and greater throughput.”
Dave Martin
CEO/Founder, PulFORCE
INNOVOATION:
Modern resins and high Vf applications have necessitated a new breed of pultrusion machine capable of handling continuous production at increased speeds under extremely high pull loads. Earlier designs, commonly found around the industry, were and are good designs which work well under the typical loads found in conventional pultrusion operations. These machines are built for general use applications and meet the needs of that market. However, under extreme loads these older designs begin to experience issues that negatively affect the quality of the part, the longevity of the machine, and the structural integrity of the assembly. Higher loads can cause part slippage in the clamps, can cause the frame to excessively flex, can cause the carriage to deform, and can greatly accelerate wear on the bearings.
In early 2020, PulFORCE was approached by a customer who was experiencing these same issues, and was given the specific challenge to develop a compact machine capable of 100,000lbs of pull and clamp force, suitable for operation in an exceptionally harsh environment.
We addressed these issues by engaging in an extensive engineering exercise which analyzed every aspect of the machine. Our CAD models were loaded into FEA software which allowed us to simulate the expected pull forces and understand how our designs were reacting. We were able to identify the following critical areas of machine design and and significantly improve performance:
Solution: PulFORCE incorporates two I-Beams into the machine frame for mounting shaped linear guide bearing rails. These I-Beams include a precision milled pad with indexing shoulder for precise mounting and alignment of the rails directly over the web of the I-Beams. The indexing shoulder and added support of the I-Beam create an ideal design which eliminates any flex or warp in the bearings which cause snap-back.
Solution: By incorporating solid side blocks, as well as proper gussets top and bottom of the carriage we were able to eliminate any puller deformation. PulFORCE used FEA design software to determine the proper size and placement of the blocks and gussets which ensured the structural integrity of the puller carriage, including a 2X safety factor.
Frame flex will negatively impact process alignment, a fluid handoff, part quality, components, machine lifespan and a host of other issues.
Solution: PulFORCE engaged in an FEA guided design process which yielded an ultra-stiff frame design by incorporating innovative bracing, supported I-beams and strategically placed gussets. The resulting weldment outperformed much heavier frames while maintaining a compact, narrow width.
