How we verify the technical data on our pages

Where our numbers come from

We do not run a lab and we do not publish our own test results. Our figures come from the people who make the resin and the bodies that write the rules, and we go to the original wherever we can rather than a summary of it.

Our values are typical. Your data sheet and COA govern.

Every property range on our site is a typical published value, written with “about” or “typical” and with its test conditions. It is a starting point for comparing grades and a sanity check on a data sheet. It is not a specification, and it is not a value for a grade we are quoting.

For design, the producer’s current data sheet for the exact grade you run governs. For a delivery, the certificate of analysis (COA) for that lot governs. For food contact, UL or automotive approvals, the producer’s letter or listing for that exact grade governs. If our page and your data sheet disagree, go by the data sheet, and tell us so we can check our page.

Research and two fact-check passes before a page goes live

Each new or rewritten technical page goes through research and two separate fact-check passes before it is published.

• Research with sources. Each number in a draft is traced to a source. Anything we cannot pin down is held back as an open question, not published with a guess.
• First pass: every claim. Every number, test method and condition, standard and its current status, regulation, organization name and market claim is checked against a primary source where one exists. If it cannot be verified, it is narrowed to what can be defended or removed.
• Second pass: fresh eyes on the finished page. A separate review reads the page top to bottom as a buyer would. It re-checks the claims most likely to be wrong or to go stale, looks for contradictions with our other pages, and removes overclaims.
• Business facts come from the business. Order sizes, packaging, how we quote and what we will and will not claim come from one set of facts set by ResinBridge, not from the writer. Where we are not sure we can source a resin family, the page says we quote it through supply partners case by case.
• Open questions stay off the page. Anything still uncertain after both passes is left out until it can be confirmed.

Consistency checks against our reference charts

A number that is right on one page and different on another is still a problem for a buyer. Our resin drying chart, processing chart and typical properties pages are the site’s reference values, and every new page is checked against them.

• When pages disagree, we find out which is right. If a new page conflicts with an existing one, we go back to the source and correct whichever is wrong, including the older page.
• When producers disagree, we say so. Where two producers publish materially different figures, we give the range they support or note the difference, rather than inventing an average neither producer stands behind.
• Site-wide facts come from one set of numbers. Order sizes, packaging weights and how we quote are checked against the same business facts on every new page: for example, a gaylord holds about 1,000–1,600 lb depending on the resin. See gaylord, LTL and truckload sizes.

How we word typical ranges

• Typical, not specified. We write ranges as “about” or “typical” values. They are a starting point and a sanity check, not a specification. Your grade’s data sheet and the lot COA govern.
• Test conditions with every flow number. A melt index without its conditions can mislead. We write polyethylene melt index at 190°C / 374°F, 2.16 kg and polypropylene melt flow at 230°C / 446°F, 2.16 kg, with the method (ASTM D1238 or ISO 1133), and say when two tests do not compare.
• Methods and units stated. We name the test method where it changes the number, and give °C with °F.
• Careful words. We say “often” when something is common but not universal, and save “usually” for cases we are sure of.
• Grade names are examples. When a page names a producer’s grade, it is a published example to help you compare, not an endorsement and not a claim that we supply it.
• Dated pages. Our guides and reference pages show the month they were last updated, and pages on rules that are still changing, such as PFAS laws, say which month they reflect.

What we never publish

• Market prices. No resin prices, cents-per-pound figures, spreads or index values on our guides. Resin prices move monthly and depend on grade, quantity, package and ship-to city, so we explain what drives price and quote each request. See how resin is priced. The one exception is a surplus lot listing on our surplus page, which shows the asking price for that one lot.
• Customer names. We do not name customers, and we do not name our supply partners.
• Stock or ownership claims. We do not own plants, labs or warehouses. Apart from a specific surplus lot listed on our surplus page, we do not claim to hold stock. Material ships from 22+ partner warehouse locations, quoted case by case.
• Certifications we do not hold. We do not claim company certifications. Approvals such as FDA letters and UL listings belong to the producer’s grade, and we say so.
• Guarantees we cannot keep. We aim to send a quote within one to three business days and confirm a ship date with each quote, but we do not promise lead times on the site.
• Legal advice. Regulatory summaries are a starting point. Check with your compliance advisor before you rely on them.

Quote requests are a separate step

Checking pages and reviewing quote requests are separate. Pages go through the research and fact-check passes above; that is not a chemist’s sign-off on every page. Every quote request is read by a polymer chemist, who checks the resin family, fill, melt flow and its test method, stabilizers, color, and any food-contact, UL or automotive requirement, and asks questions when something is missing. If we offer an equivalent rather than the exact grade, we tell you how close it is and which properties differ before you order. See about ResinBridge.

How often pages are reviewed

We review pages when standards or producer data change, and at least once a year.

• What prompts a review. When we learn that a standard has been revised or withdrawn, a regulation or deadline has changed, a grade has been discontinued or a data sheet has changed, we go back to the pages that cite it.
• The date changes when the content changes. We update the date on a page when we change what it says, not to make it look fresh.

How to report an error

If you think a number, standard or rule on our site is wrong or out of date, email quotes@resinbridge.com. Send the page, the statement, and your source if you have one, such as a data sheet, standard or regulation. We check it against the primary source, correct the page if we were wrong, update its date, and let you know what we changed.

Common questions

If your grade is not listed, tell us what you run. We source commodity, engineering and specialty resins.