Hotmelts for waterproofing connectors have been state of the art technology for many years. However, Macromelt molding is more than a waterproofing adhesive bonding method. The Macromelt moulding adhesive not only prevents the ingress of moisture into the connector. It also provides the connector with mechanical strain-relief thus eliminating other plastic parts, clips or clamps previously required.
The Macromelt moulding polyamide-based hot-melt adhesives have a melting range of 120°C to 180°C and are low viscosity and present good adhesion to many plastics such as polyethylene, polyvinyl chloride and polyamide.
The process is related to injection moulding where heated hot-melt adhesive is injected into a tool. The thin molten mass will flow around filigree components at low pressure unlike the high pressure required for conventional plastic injection moulding. The adhesive will flows into the narrowest spaces at a pressure between 5 and 10 bar.
The low pressure makes the entire process economical, as both the machine and the tool can be designed for these low loads, allowing the use of inexpensive aluminium tooling.
Hotmelt protects against water and mechanical impairment....
Pictured: Flexible PCB to PVC Wiring
System Components
In MM moulding the first requirement is the actual Macromelt hot-melts, the second is a special moulding machine such as the Optimel 2000. The OM2000 was developed especially for the MM process. The system also requires custom made tooling to suit the application. The advantages of Macromelt moldings are the low cost tooling, the high quality of the moulded part, its repeatability and the reduction of waste as runners etc. can be re-melted for re-use. When Macromelt assumes the functions of other moulded parts, additional production steps are eliminated.
Pictured: Custom Grommet
The process involves heating and converting MM Thermoplastic materials into a molten mass that is then injected into an aluminium mould. The heat is drawn out by the tooling from the molten mass allowing the material to re-solidify. This means that no chemical reactions are involved in the Macromelt molding process and therefore no solvent fumes are released.
The process involves heating and converting Macromelt Thermoplastic materials...
Application Examples
The process involves heating and converting MM Thermoplastic materials into a molten mass that is then injected into an aluminium mould. The heat is drawn out by the tooling from the molten mass allowing the material to re-solidify. This means that no chemical reactions are involved in the Macromelt molding process and therefore no solvent fumes are released.