Injection Molding | 1 MINUTE READ

Trexel Adds Chemical Foaming Agent to Its Product Line

Special additive offers economical microcellular foaming for low-volume jobs with PE, PP.


Facebook Share Icon LinkedIn Share Icon Twitter Share Icon Share by EMail icon Print Icon

Trexel, Inc., Wilmington, Mass., a long-time proponent of physical foaming with its MuCell direct gas-injection process, has now added chemical foaming to its microcellular technology portfolio. Trexel has partnered with masterbatch producer Polyfil Corp., Rockaway, N.J., which has offered EcoCell blowing-agent concentrates since 2009. Polyfil’s patented technology uses 0.08-micron nanoparticles of calcium carbonate in an endothermic reaction that yields only carbon dioxide, water, and citric salts, whereas most endothermic chemical foaming agents (CFAs) reportedly also produce soda ash, which can cause plateout and corrosion. Besides being a “cleaner” reaction, EcoCell is said to produce smaller cell sizes and more uniform cell distribution. Trexel describes it as a microcellular cell structure of 20-80 microns.

While Polyfil will contine to market its EcoCell CFA for extrusion, Trexel will now offer it under the TecoCell name for injection molding and automotive blow molding of products like ducts. Weight reductions with TecoCell are typically 7-10% in injection molding (compared with more than 20% density reductions commonly achieved with MuCell) and 30-35% in accumulator blow molding. TecoCell reacts at 200-280 C (392-536 F), suiting it mainly to PE and PP, whereas MuCell is also used with higher-temperature engineering resins. TecoCell also works well with unfilled resins, whereas MuCell is generally used with filled or reinforced materials.

Trexel says MuCell and TecoCell are complimentary rather than competing technologies. TecoCell requires no equipment modification, unlike MuCell, which needs a modified screw and barrel. That gives TecoCell an economic advantage for low-volume jobs using unfilled or talc-filled PE and PP. But once the equipment investment for MuCell is made, the ongoing costs of MuCell nitrogen injection are lower—typically less than 1¢/part vs. 3-9¢/lb added cost for 1-3% use levels of TecoCell. Because nitrogen is a more efficient foaming agent than CO2, MuCell will generally produce higher foaming levels and density reduction, according to Trexel. MuCell is also said to be superior in reducing warpage, but TecoCell may produce better surface finish—although not Class A.


  • Enhancing Biopolymers: Additives Are Needed for Toughness, Heat Resistance & Processability

    Plastics are going “green,” but they will need some help to get there. Biodegradable polymers derived from renewable resources are attracting lots of interest and publicity, but that enthusiasm is counterbalanced by persistent questions of availability, cost, performance, and processability. All these issues are inter-related: Increasing demand will lead to more capacity, which will presumably lead to lower prices. But the foundation is market demand, which ultimately depends on whether biopolymers will have the performance properties and processability to compete with existing non-renewable plastics.

  • Hot-Fill Packaging: OPP and 'Panel-Less' PET Bottles Grab the Spotlight

    Improved clarity and cost competitiveness, added to its inherent heat resistance, are reviving OPP’s prospects in hot-fill barrier containers. But hot-fill PET containers are raising the bar with higher productivity and ‘panel-less’ bottle designs.

  • Understanding the ‘Science’ of Color

    And as with all sciences, there are fundamentals that must be considered to do color right. Here’s a helpful start.