Providing Solutions to the Challenges of Back Foaming Operations
Back foaming is the application of an insulating layer of mostly flexible foam to a substrate in order to reduce transmission of energy in the form of heat, sound or both. By far the most common application for back foaming is in the transportation industry (road, rail, water or air transportation) where the passenger or freight areas need to be shielded from noise or heat generated by movement (either moving parts of an engine/power transmission system or friction/vibration). Although insulating polyurethane foam can be molded as a sheet and subsequently glued to the substrate, foaming directly onto the substrate allows for a one-step process that puts foam only into the areas required. This avoids a costly extra step, reducing labor processing, expense of adhesives and foam scrap.
Typically the substrate would be a carpet for vehicle interiors, a so-called heavy layer (heavily filled rubber sheet) for vehicle motor housing (e.g. under the hood), or rigid polyurethane for parcel trays and bulkheads. Chem-Trend’s over five decades of experience helping polyurethane molding operations improve efficiency and reduce scrap have been instrumental to developing products for the back foaming process.
Closed-celled and Open-celled Foam
Although there appears to be no consensus in the industry on whether closed- or open-celled foam surfaces give better insulation properties, most back foamers have changed from solvent- to water-based release agents – despite the tendency for water-based products to produce a closed-cell surface. Most customers require a dry surface to the finished part, not only to avoid transfer of the release agent to the "A" side of parts when they're stacked, but also for psychological reasons. A surface that provides a “slippery” or "greasy" feel is often viewed negatively and has an unclean connotation.
Another important requirement of release agents used for back foaming processes is a long timeframe between necessary mold cleaning cycles. Increasing the time between cleanings leads to higher productivity in each mold. These aspects can all be taken into consideration and specifically formulated into release agents.
Chem-Trend Portfolio of Solutions
Chem-Trend offers a wide range of products that meet the needs of our customers' manufacturing, environmental and safety requirements. We understand that our customers have increasing pressure for part quality and performance. Our mold release agents and support products for back foaming applications provide optimal release ease, dryer part finish, less build-up and improved foam flow.
Our mold release agents have provided a competitive advantage to manufacturers around the world with water- and solvent-based release agent solutions that can maximize productivity while meeting the most demanding specifications and operating conditions. Our complete line of mold cleaners, sealers and preparation pastes provide an excellent solution in preparing new tooling and provide an effective base for enhancing release for difficult-to-release mold surfaces. Chem-Trend® mold sealers and pastes have been formulated to work most efficiently in a system approach in combination with Chem-Trend® release agents in pre-production or in-line production touch-up applications. We also offer anti-squeak products that can be applied to eliminate squeak where rubbing could cause noises that might be heard by the end user.
Our solutions can be supplied in either concentrate or ready-to-use forms.
Chem-Trend understand the challenges faced in the back foaming process because we have spent more than fifty years working with polyurethane molding customers around the globe on their shop floors. That experience is a key part of our ability to understand industry challenges and develop appropriate solutions that improve the productivity of our customers.
To learn more about what Chem-Trend has to offer to those involved in polyurethane back foaming operations, or any other polyurethane molding process, read our main Polyurethane Molding section, or contact us directly.