Polyshot Corp. has introduced its vacuum brazing technology to moldmakers for fusing of multi-component mold cores and cavity assemblies for cost-reducing conformal cooling systems. As a leading manufacturer of hot-runner systems, Polyshot has successfully translated its fusion technology for hot runners to injection molders who seek the advantages of conformal cooling.Polyshot is offering its value-added vacuum brazing services in response to growing customer demand, according to the company. “Our unique technology has delivered great results for our hot runner business and is now gaining strong traction among moldmakers who seek an efficient and affordable method to create conformal cooling systems,” said Doug Hepler, president of Polyshot Corp. The expansion of the unique fusion technology to conformal cooling has resulted in strong growth with more than half the business coming from overseas customers, according to Hepler.
For hot runners, Polyshot’s fusion technology fuses together two or more steel plates to create internal flow paths. Polyshot’s technology allows the creation of internal full round flow paths that allow generous sweeping curves and no hold-up areas. These internal flow paths withstand very high injection pressures and external forces while still maintaining the integrity of the brazed joint.
For conformal cooling systems, Polyshot’s vacuum brazing technology is a proprietary process which makes use of a high-temperature vacuum furnace. Rough cores and cavities with machined conformal cooling paths are fused together by Polyshot in a stack which is typically 1 to 6 layers. Typical materials that are fused include H-13, 420 stainless steel, and S-7. Cores are shipped back to the customer in a soft state, approximately 30 RC, and require additional post brazing hardening at a local heat treat facility. The typical turnaround time for the process is 1-2 weeks.
The use of conformal cooling in mold cavities can have a substantial impact on mold cycle time, part quality, and part repeatability. Conformal cooling channels follow the shape of the cavity and core and are able to reach hot spots and promote temperature uniformity of the molded plastic materials. They reduce cooling time and achieve overall cycle time reductions of up to 60%, resulting in substantial cost savings.
The vacuum brazing process is targeted for high-cavitation molds (32-128 cavities) for high-volume packaging applications such as caps and closures.
