MOLDING - GLASS ALTERNATIVE MATERIAL - COC
Applications: Uses include glass replacement and alternative opportunities, optical lenses, light guides, micro titer plates, syringe bodies, tubing connectors, catheter manifolds, and lids.
Metallocene-catalyzed COCs offer excellent optical properties, high flow, and ultra-low moisture absorption. In addition, their density is 3% lower than that of polystyrene and 15% less than polycarbonate and acrylics. Their density is also 50% of glass.
COCs are amorphous polymers with high modulus and surface hardness. Chemically, they resist hydrolytic degradation, aqueous acids and bases, and most polar and oxygenated solvents. In injection molding, they provide high precision, and they flow well to fill complex, thin-walled parts with low shrinkage and warpage. Because COCs’ stiffness is 25% greater than that of polycarbonate, they lend themselves to molding thinner walls.
COC Properties & Advantages: COC has a glass-transition temperature (Tg) between 70 and 185 C (158 to 365 F). As a result, their heat-deflection temperature (HDT) ranges from 75 to 170 C (167 to 338 F). Grades with Tg above about 140 C (284 F) have a flexural modulus in the vicinity of 500,000 psi and elongation at break of 3% to 4%. Those with a lower Tg have a lower modulus but greater elongation (up to 10%).
Shrinkage in the flow direction is only slightly greater than that in the transverse direction, so very flat parts can be molded. COCs’ good stiffness and flow means that parts can have walls down to 1 mm or less.
The resin replicates extremely fine molded features. One precision COC laboratory component, for instance, has complex channels as small as 10 microns. COCs also faithfully reproduce sub-micron surface patterns, such as those found on diffraction gratings and optical data-storage media.
Glass-reinforced, mineral-filled, flame-retardant (UL 94V-2 and V-0), and impact-modified grades have been developed. There are also grades containing stainless-steel fibers to impart electrical conductivity.
Secondary Operations: COCs can be finished by pre-treatment and/or post treatment for printing, coating, and metalizing as well as joining and machining. COCs are nonpolar materials, so relatively few materials stick to them.
COC parts can be solvent bonded. COCs can also be ultrasonically welded.
We have had tremendous experience in molding these resins and welcome any new or potential opportunity you may have.