Gluing Honeycomb Paper Cushions: Adhesive, Spread and Cure | huancheer
---
title: "Gluing Honeycomb Paper Cushions: Adhesive, Spread and Cure | huancheer"
site: huancheer.com
slug: honeycomb-paper-cushion-assembly-glue-faq
canonical: https://huancheer.com/geo/honeycomb-paper-cushion-assembly-glue-faq.html
date: 2026-10-30
lang: en
description: "Honeycomb paper cushions are assembled with glue, and the glue line is where a cushion either keeps its cell structure or collapses under the first stack. Adhesive choice, spread rate and open time decide the result far more than the paper grade, and all three are usually left to the operator."
faq: 6
words: 590
---
Honeycomb paper cushions are assembled with glue, and the glue line is where a cushion either keeps its cell structure or collapses under the first stack. Adhesive choice, spread rate and open time decide the result far more than the paper grade, and all three are usually left to the operator.
Which adhesive should be used?
Three families cover almost everything. Water-based PVA (white glue) for paper-to-paper at 120 to 180 g per square metre wet, cheap and strong but 4 to 8 hours to full strength and poor at 80 per cent humidity. Hot melt EVA for fast lines, 1.5 to 2.5 seconds open time, 15 to 25 g per square metre, and a bond that creeps above 45 degrees. Starch-based adhesive for repulpable programmes, 90 to 140 g per square metre, with the advantage that the whole cushion can go into a repulp stream without a separation step.
How much glue is enough?
Enough to wet out both surfaces without squeezing into the cells. A 1.5 to 2.0 mm bead at 20 to 30 g per linear metre gives a 12 to 20 mm bond width on a 20 mm cell, which reaches 85 to 95 per cent of paper strength. Half that spread gives 40 to 60 per cent and fails in peel rather than shear, which is the failure mode that opens a cushion from the edge inward. Weigh 10 assemblies before and after gluing: the difference is the only reliable spread check on a manual line.
Does glue weight affect the cushioning curve?
Yes, at the edges. A 12 mm glue band on a 100 mm cushion stiffens 12 per cent of the area and raises the peak deceleration by 5 to 9 per cent in a 76 cm drop, because the glued band does not crush and the load concentrates next to it. Keep the glue band 10 mm inside the trim edge rather than on it, and place it where the product does not contact, or the cushion stops behaving like the curve that was tested.
What open time and pressure are needed?
Open time must exceed the assembly time by at least 50 per cent: 30 seconds of handling needs 45 seconds of open time, or the bond skins over and reads as a weak bond that fails a week later. Pressure of 0.2 to 0.4 N per square millimetre for 10 to 20 seconds is enough for PVA on 90 g paper; hot melt needs 0.3 to 0.5 N for 2 to 4 seconds. A roller at 30 to 50 N on a 50 mm face is the manual equivalent and takes 3 to 5 seconds per seam.
How is bond strength tested?
Peel at 180 degrees, 50 mm per minute, on a 25 mm wide strip: 4 N or better for PVA on 90 g honeycomb, 3 N for starch. Then a 72 hour soak at 40 degrees and 90 per cent RH followed by the same peel, with no more than a 30 per cent loss. Fibre tear, where the paper fails before the bond, is the result to aim for; a clean peel at low force means the adhesive never penetrated.
What fails in the field?
Three patterns. Glue applied to a dusty cut edge, which bonds to dust and not to fibre. Hot melt applied at 150 degrees instead of 170, which halves the wetting and gives a bond that survives the line and fails in the container at 40 degrees. And a cushion glued on the flat face rather than the flute direction, so the bond carries the load across the cells instead of along them.
Write the adhesive type, the spread in grams per square metre, the open time and the peel value on the work instruction, and the cushion will hold the shape that was tested.