NGCNext Generation Chemical

Polyester polyols for PUR hot-melt adhesives.

Crystalline 1,6-hexanediol and 1,4-butanediol adipates, a fast-set grade, an amorphous grade and liquid grades: everything you need to build and tune a reactive (PUR) hot melt. 14 NGC Ester HM grades plus 4 support grades, supplied and supported in the UK and Europe.

Request lab samplesDownload the hot-melt brochure (PDF)
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Send us your current grade and TDS. We match OH value, viscosity, acid value and melting point, and send lab samples for your trial.

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The basics

How to build a reactive hot melt

A reactive (PUR) hot melt is a blend of polyester polyols reacted with MDI. Each type of polyester does a different job.

Crystalline: set and green strength

1,6-hexanediol and 1,4-butanediol adipates crystallise as the bond line cools, so the joint sets fast and holds early. Higher MW gives a tougher, more elastic film.

Amorphous: tack and adhesion

An isophthalic/adipic polyester adds hot tack and green strength, and helps adhesion to polar substrates such as wood, paper and metal.

Liquid: open time and flexibility

Liquid and low-melt adipates give longer open time, a softer bond line and better adhesion to plastics.

  1. Pick the blend. Start with a crystalline grade as the largest part, then add amorphous for tack and liquid for open time.
  2. Melt and dry. Melt the polyesters together and dry under vacuum. Water reacts with MDI, so keep it as low as you can.
  3. React with MDI at an OH:NCO ratio of about 1:2.2, so the prepolymer ends in free NCO groups. Pack it away from moisture.
  4. Apply and cure. The hot melt sets as it cools, then cures with moisture in the air to its final strength and heat resistance.

General guidance only. Tune the blend and ratio on your own line, and trial before use.

Applications

Where PUR hot melts are used

Each line needs a different balance of set speed, open time, green strength, flexibility and heat resistance. These are the usual starting points. Your own trial decides the final blend.

Furniture and panels

Edge banding

Edge bands are pressed onto the board edge at high line speed, so the hot melt must grab fast and hold the band while the panel moves on to trimming.

After moisture cure, the bond line also needs heat and water resistance for kitchen and bathroom furniture.

Grades to look at

  • Fast set: NGC Ester 76930 HM
  • Main crystalline backbone: NGC Ester 76630 HM
  • Tack and adhesion to wood: NGC Ester 76135 HM
See the grade table
Edgebanding machine pressing a white edge band onto the chipboard edge of an oak-decor furniture panel with steel pressure rollers
Illustrative image.
Profile wrapping line with rows of small pressure rollers pressing a wood-grain decor foil onto a long white profile
Illustrative image.

Windows, doors and furniture

Profile wrapping

Decor foil is wrapped around the curves of PVC, aluminium or MDF profiles. The hot melt needs enough open time to follow the shape, then high green strength so the foil does not lift at the edges.

Grades to look at

  • Crystalline: NGC Ester 76630 HM, 76620 HM
  • Amorphous for green strength: NGC Ester 76135 HM
  • Liquid for open time and adhesion to plastics: NGC Ester 74537 HM
See the grade table

Print finishing

Bookbinding

Perfect-bound books need a thin glue line that sets quickly, so blocks can be trimmed soon after binding.

Once cured, the spine should stay flexible so the book opens flat without pages coming loose.

Grades to look at

  • Crystalline: NGC Ester 76630 HM, 76637 HM (lower melt viscosity)
  • Adhesion to paper: NGC Ester 76135 HM
See the grade table
Stack of plain perfect-bound paperback book blocks in white, grey and pale blue covers on a workbench beside a binding machine
Illustrative image.
Grey woven fabric laminated to a thin foam sheet next to a fabric-covered car door-panel insert, with laminating rollers behind
Illustrative image.

Textiles and vehicle interiors

Textile and interior lamination

Fabric is laminated to foam, or to door-panel and headliner substrates. The bond line must stay soft and flexible, so the fabric keeps its feel, and hold up to heat inside the vehicle.

Grades to look at

  • Flexible crystalline: NGC Ester 76617 HM, 76612 HM
  • Liquid and low-melt soft segments: NGC Ester 74537 HM, 76535 HM, 71145 HM
See the grade table
NGC Ester HM

Hot-melt grades

Typical values. Confirmed on each TDS. Melting points are approximate. Viscosity is shown with its measuring temperature.

Request TDS/SDS
GradeChemistryOH valuemg KOH/gAcid valuemg KOH/g, maxAvg MWg/molViscositymPa·s at °CStateat 25 °CMelting pointor TgRole in the hot meltSample
Crystalline: set and green strength
NGC Ester 76630 HM1,6-hexanediol adipate28–32≤ 0.53,7005,500 at 60Solid (crystalline)approx 55 °CMain crystalline backbone; balanced open/set time; high green strengthRequest sample
NGC Ester 76620 HM1,6-hexanediol adipate18–22≤ 1.05,60016,500 at 70Solid (crystalline)approx 56 °CHigher MW; tougher film; longer chains for flexibilityRequest sample
NGC Ester 76617 HM1,6-hexanediol adipate14–20≤ 1.06,500On requestSolid (crystalline)approx 57 °CHigh MW crystalline for textile and flexible bondsRequest sample
NGC Ester 76612 HM1,6-hexanediol adipate10–16≤ 1.08,500On requestSolid (crystalline)approx 57 °CHighest MW crystalline; elastic bond linesRequest sample
NGC Ester 76637 HM1,6-hexanediol adipate35–39≤ 0.53,0003,000 at 60Solid (crystalline)approx 55 °CLower MW crystalline; lower melt viscosityRequest sample
NGC Ester 76656 HM1,6-hexanediol adipate53–59≤ 0.52,0001,100 at 60Solid (crystalline)approx 53 °CPrepolymers; fast crystallising soft segmentRequest sample
NGC Ester 74445 HM1,4-butanediol adipate43–47≤ 0.52,5002,200 at 60Solid (crystalline)approx 55 °CContact and footwear adhesives; fast crystallisationRequest sample
NGC Ester 74457 HM1,4-butanediol adipate54–58≤ 0.52,0001,400 at 60Solid (crystalline)approx 55 °CContact adhesives; TPU-type adhesivesRequest sample
NGC Ester 72235 HMEthylene glycol adipate33–37≤ 0.53,2003,500 at 60Solidapprox 50 °CCrystalline modifierRequest sample
Crystalline, fast-set
NGC Ester 76930 HM1,6-hexanediol long-chain diacid polyester28–32≤ 0.53,7502,400 at 80Solid (highly crystalline)approx 70 °CVery fast setting; edgebanding and high line speedRequest sample
Amorphous
NGC Ester 76135 HMIsophthalic/adipic acid hexanediol polyester33–37≤ 0.53,2007,600 at 60SolidTg on TDSRaises green strength and adhesion to polar substratesRequest sample
Liquid and low-melt
NGC Ester 74537 HMButanediol/neopentyl glycol adipate35–39≤ 0.53,00010,000 at 40LiquidTg < −40 °CLonger open time; flexibility; adhesion to plasticsRequest sample
NGC Ester 76535 HMHexanediol/neopentyl glycol adipate32–38≤ 0.53,20012,000 at 40Paste/solidTg on TDSSoft segment; open-time controlRequest sample
NGC Ester 71145 HMDiethylene glycol adipate43–47≤ 0.52,50012,400 at 25LiquidTg < −40 °CLow-cost liquid soft segment; laminating adhesivesRequest sample
Support grades from the main range
NGC Ester 72140BAliphatic polyester38–42< 0.52,8002,700–3,300 at 60LiquidOn TDSLiquid soft segmentRequest sample
NGC Ester 72156BAliphatic polyester50–55< 0.52,2501,350–1,650 at 60—On TDSAdhesives and TPU-type adhesivesRequest sample
NGC Ester 72120BAliphatic polyester108–116< 0.51,000100–300 at 75—On TDSLow MW; tack and hardness tuningRequest sample
NGC Ester 74310NHAliphatic polyester106–118< 1.01,200500–800 at 75—On TDSCoatings and adhesives; PUDRequest sample

Typical values, not a specification. The TDS for your order is the agreed specification. Price, packaging, lead time and REACH status are confirmed with each quotation. Always trial before use.

PDF

Downloads

Hot-melt polyols brochure

The hot-melt grades and support grades, how to build an RHM, and how to match your current grade. 2 pages, October 2026.

Download PDF

NGC Ester catalogue

All 57 NGC Ester grades: hot-melt, CASE and rigid foam. Issue 2, October 2026.

Download PDF
Request lab samplesAll polyester polyols