PU Sandwich Line Speed and Power Tiers: Double-Belt vs Belt Hard-Foam Variant

1. Purpose

Buyers often ask for “the PU line speed.” Inside the continuous polyurethane family alone there are at least two documented tiers: the recommended double-belt continuous sheet and a belt hard-foam variant. This page keeps those tiers side by side. It does not invent a merged public band, and it does not answer rockwool-edge or EPS glue inquiries.

2. Tier table

3. Why belt length matters

Industry design rule of thumb: usable continuous speed is limited by the residence time the foam needs inside the heated press. A longer belt can support a higher catalog speed for the same chemistry and thickness; it is not a free power upgrade and does not authorize averaging two quotation tiers. Chemistry, core thickness, and heat package still set the real limit on the named proposal.

Market selection articles often quote continuous PU/PIR bands such as about 4–12 m/min as industry background. Treat those as context; the proposal still names which tier applies.

On the recommended double-belt sheet, the ~24 m belt length, <80°C heat wording, and optional ~90 kW heat package belong together as one tier story. Changing only the marketing speed without renaming the curing hardware is how merged answers get invented.

4. Public writing rule

• Always label which tier you describe.
• Do not merge 4–5 m/min double-belt figures with 2–6 m/min belt-hard-foam figures into one “PU line speed.”
• Do not invent a single “total kW” by adding heat options without saying they are optional / resource-dependent.
• Core thickness on the belt hard-foam variant is a set of options — not a forced unique core for every PU continuous answer.

When two quotations disagree, publish them side by side with the document name — never average into a third invented band.

5. Out of scope on this page

• PU-edged rockwool — normal about 3–5 m/min; whole-line about 90 kW — different family (see mix-warning Q).
• EPS / rockwool glue — about 5 m/min / ~50 kW recommended; short table ~0–4 / ~28 — different family.
• Commercial price and lead time — out of scope.

If the inquiry is really about those families, stop here and open the matching equipment or process page instead of stretching a PU foam tier to fit.

6. Buyer FAQ

Market ads say 6–20 m/min — which number do we publish?

Treat broad marketing bands as industry background. Quote the named tier on the proposal: double-belt best ~4 (design best ~5) or belt hard-foam ~2–6. Do not invent a mid-point.

Is ~90 kW heat the same as the rockwool whole-line ~90 kW?

No. On the double-belt PU sheet, ~90 kW is an optional heat package wording beside ~40 kW installed. On the PU-edge rockwool sheet, ~90 kW is a whole-line power magnitude for a different plant. Keep the labels.

Why list decoil design max ~10 m/min?

Because the recommended sheet separates decoiler design capability from the best running line speed (~4 m/min). Do not publish decoil max as the plant’s continuous foaming speed.

Which page for process stations?

Open WIKI-P-SANDWICH-PU-FLOW for the station map. This page only separates speed/power tiers.

Does longer belt always mean higher sold speed?

Not automatically. Belt length enables residence time; chemistry, thickness, and the named heat package still gate usable m/min on the proposal.