Sơn Kẻ Đường Nhiệt Dẻo JT/T 280

The 2022 edition raised the floor

Under the 2004 edition a factory could sell an “ordinary” hot-melt with no beads in the mix. The 2022 revision deleted that product outright — hot-melt now exists in exactly two types, and both must carry premix glass beads:

The practical consequence: a “JT/T 280 hot-melt” offer with 10% or 20% beads — or none — is being quoted against a standard that no longer exists. If a tender written before 2023 still cites the 2004 edition, ask which text governs before comparing prices; the bead content alone moves the cost significantly.

Performance requirements — Table 3, reflective type

Two of these are worth reading twice. The double compressive test — cold and at 60 °C — is aimed at hot climates, where a line that is hard in the lab can still track and deform under summer traffic. And the 200 °C heating-stability hold simulates the kettle: four hours at working temperature without scorching or drifting off colour is what separates a line that stays white from one that yellows the day it is laid.

The recipe’s inputs are specified too

Where BS 3262 and AASHTO M249 mostly test the finished powder, JT/T 280-2022 goes a level deeper and writes normative specs for the raw materials themselves — Appendix A for the resin, Appendix B for the polyethylene wax:

This is the audit-the-inputs philosophy the Chinese network runs on, and it suits a factory like ours: the resin and wax arrive with their own test numbers, the mix leaves with the batch COA, and both paper trails point at the same standard.

The bag melts into the kettle

The most distinctive clause in the 2022 edition is the packaging: hot-melt paint shall be packed in a dedicated EVA sack (clause 8.2.1, Appendix C) that goes into the preheater with the paint. At 140 °C the stirred melt dissolves the whole bag within 3 minutes — no cutting, no emptying, no dust at the kettle, no pile of used bags on the roadside. The same film still has to survive logistics: 4 h at 90 °C without sticking, a 2.5 m stack for three days, a 2 m drop, all without splitting. Type I single-layer sacks hold 25.0 kg. Tell us at order whether your project runs the melt-in route — export orders that prefer a conventional woven outer bag can have one over the EVA liner.

JT/T 280, BS 3262, AASHTO M249 — which to cite

On bead content the three standards agree more than they differ — the JT/T 280 floor of 30% sits inside the AASHTO band and above the British one. If your engineer is a Chinese contractor, the tender almost certainly says JT/T 280 and this is the page to quote from; for BS or AASHTO texts, see the related products below. Either way, name the edition year in the contract.