Acetal Copolymer Rod, Food Grade

This is the purpose-built food-grade copolymer, and it is blue for a reason: blue does not occur in food, so a chip that finds its way into a product line shows up against it. It goes into scrapers and wear strips, star wheels and timing screws, gears and sprockets in wash-down machinery, filling nozzles and guide rails - the parts that touch product all day in food, beverage and pharmaceutical plants.

On food contact, stated precisely. This is a food-grade acetal copolymer and the applicable clearance is 21 CFR 177.2470, which covers polyoxymethylene COPOLYMER - a different section from 177.2480, which covers the homopolymer, and the industry routinely cites the wrong one. Two things follow. The clearance belongs to the resin as made, so what you want in your file is the mill certificate for the lot you are shipped, and we will get it. And the FDA acetal clearances cap use temperature at 250F, which is below where the material itself gives up - so the compliant temperature ceiling is lower than the mechanical one.

Read this before you specify it, because it is the thing buyers get wrong. THE BLUE IS FOR VISUAL DETECTION ONLY. This material is NOT metal-detectable and NOT x-ray-detectable. Detectable acetal is a separate purpose-built grade - also blue, which is exactly why the two get confused - loaded so that a fragment trips a metal detector or shows on an x-ray inspection line. If your HACCP plan relies on detection equipment rather than on somebody seeing the chip, this is not the grade you need, and we can quote the one that is.

What we do not claim. No USDA, NSF, 3-A Dairy, EU or USP statement is made for this grade. The trade literature for acetal copolymer says "certain grades" carry those approvals, and "certain grades" is not this one - if you need a specific approval named on a certificate, tell us which and we will find out what we can actually supply against it before you order.

Published figures for unfilled copolymer: tensile strength around 8,800 psi, flexural modulus about 370,000 psi, Rockwell M80, notched Izod around 1.0 ft-lb/in, and a melting point of 329F with continuous service to roughly 180F in air. Water absorption is about 0.2 percent at 24 hours - low enough that a part machined dry stays the size you cut it, which is exactly what nylon will not do. Specific gravity is 1.41, so a foot of 1 inch rod weighs about half a pound.

The warning worth more than any number on this page: CHLORINE ATTACKS ACETAL AT 3 TO 5 PPM. That is ordinary municipal tap water and ordinary sanitizing concentration. Acetal in a chlorinated circuit, a pool system or a sanitized wash-down line will craze and fail, and almost nobody prints this. Strong acids and strong bases attack it too. If chlorine is anywhere in the application, ask us about something else before you machine it.

Safety, and this one is specific rather than boilerplate. Acetal evolves FORMALDEHYDE above 446F and also on contact with strong acids or strong bases. OSHA's permissible exposure limit is 0.75 ppm over eight hours with a 2 ppm short-term cap, and it is a sensitizer - repeat exposure matters. Keep tools from overheating the cut, use local exhaust, and never let acetal swarf mix with PVC, because halogenated polymers can trigger sudden formaldehyde release from it. Ask us for the manufacturer's Safety Data Sheet and work to it rather than to this paragraph.

How this is sold: by the foot, cut to the length you need. The mills supply this material in 5 and 10 foot lengths and we cut from them, so tell us the length and the quantity and we will quote the cut rather than making you buy a whole stick.