Metton
From Wikipedia, the free encyclopedia
Metton LMR (liquid molding resin) is an engineering plastic material used to produce large or thick molded parts for diversified applications using processes similar to injection molding and it can be used as a replacement for traditional materials such as wood and metal.
Contents |
[edit] Mechanical and chemical properties
Metton LMR is a lightly cross linked olefinic thermoset polymers based on polydicyclopentadiene (PDCPD) with mechanical property performance attributes similar to engineering thermoplastics. In the Metton LMR molding process, two low-viscosity DCPD liquid streams - one containing an activator (A Component) and the other a catalyst (B Component) - are mixed at a 1:1 ratio and injected at near room temperature into a closed mold. The resulting exothermic reaction creates a fully polymerized part in less than 60 seconds[citation needed]. Button to button cycle times are generally 4 to 6 minutes depending upon size and geometry[citation needed].
Low internal mold pressures (15 to 30 psi.) allow part sizes up to 120 ft² (9 m²) in closed molds such as machined aluminum, nickel shell, and cast aluminum, as well as epoxy/polyester molds[citation needed]. Metton LMR is supplied in closed containers in various sizes from 55 gallon (200 liter) to 5000 gallon (19,000 liter) ISO containers to bulk on-site storage.
In addition, Metton LMR can be molded in thickness up to 12 inches(30 cm) as well as provide thick to thin transitions within the molded part to place thicker material where needed[citation needed].
The Metton LMR reaction injection molding process can produce large parts in low pressure molds with the mechanical property performance similar to injection molded engineering thermoplastics[citation needed]. The combination of Metton LMR’s process and material capabilities result in a new design freedom for replacing traditional materials such as metal, wood and fiberglass.
Small parts for Metton LMR are in the 8 to 10 ft² (1 m²) range which is the upper end for cost and size capability for standard injection molding. In addition, Metton LMR parts do not require identical part geometry for multi-cavity molds.
Fiber reinforced products tend to have poorer durability, but higher equivalent section modulus. In most semi-structural applications, Metton LMR can be designed to provide equivalent part stiffness for performance and generally at a significant weight reduction[citation needed]. Adhesion to paint and structural adhesives is excellent compared to similar materials[citation needed].
[edit] Bonding and Painting
Typically, the LMR-based parts release from the mold without mold release[citation needed]. The freshly molded part has a low surface free energy and no chemical (polar) functionality on the surface to aid in chemical adhesion. The part surface can then be oxidized to create a functional surface chemistry which provides sites for chemical bonding.
The surface of Metton LMR part is sensitive to ultraviolet light where outdoor exposure will cause surface fading or chalking in extended direct sunlight. Painting is recommended for applications requiring an aesthetic surface finish for outdoor use.
[edit] Technical details and standards compliance
The Metton LMR product family includes a standard M15XX product line and a flame-retardant product which meets the requirements for classification as U.L. V-O. The Metton M15XX includes the products M1534, M1537, M1539 and M1540. The Metton V-0 product uses a special three stream RIM injection machine.
