Glue Machine Systems in Corrugating Lines: Technical Guide

The glue machine is a critical component in any corrugating line. It applies adhesive to flute tips before the liner bonds in the double backer. Proper glue machine setup directly affects board strength, production speed, and waste rates.

Where Glue Machines Are Used:

In a standard corrugating line, adhesive is applied at two points:

1. Single Facer — Bonds liner to the first medium (single-face web)

2. Glue Machine (before Double Backer) — Bonds second liner to exposed flute tips

For 5-ply lines, additional glue application points exist between facer sections.

Types of Glue Application Systems:

Glue Roll System:

• Most common design — rotating glue roll picks up adhesive

• Doctor blade controls glue film thickness

• Glue transferred to flute tips via metering roll

• Simple, reliable, widely used

Shower Head / Curtain Coater:

• Adhesive cascades onto flute tips

• Even coverage across full web width

• Good for high-speed lines

• Requires precise viscosity control

Precision Metering Systems:

• Computer-controlled glue application

• Variable glue amount by zone

• Reduces adhesive consumption

• Found on premium high-speed lines

Key Settings and Parameters:

Glue Roll Gap:

• Controls amount of adhesive applied

• Too much: Squeeze-out, wet edges, slower drying

• Too little: Poor bond, delamination risk

• Typical range: 0.3-0.8mm depending on flute type

Glue Temperature:

• Affects viscosity and setting speed

• Traditional lines: 25-35°C

• Boiler-free lines: Room temperature to 40°C with instant-setting adhesive

• Monitor with inline temperature sensors

Glue Viscosity:

• Measured with Stein-Hall cup (seconds)

• Typical range: 30-60 seconds for corrugating adhesive

• Adjust by adding water or fresh adhesive

• Check every 30-60 minutes during production

Glue Machine Maintenance:

Daily Tasks:

• Clean glue rolls and doctor blades

• Check glue pump operation

• Verify temperature control

• Inspect for dried adhesive buildup

Weekly Tasks:

• Deep clean all glue contact surfaces

• Check bearing condition on glue rolls

• Calibrate gap settings

• Inspect doctor blade wear

Common Problems and Solutions:

Uneven Glue Application:

• Cause: Worn doctor blade, uneven roll surface, incorrect gap

• Fix: Replace blade, regrind roll, recalibrate gap

Excessive Glue Consumption:

• Cause: Gap too wide, viscosity too low, roll speed mismatch

• Fix: Reduce gap, thicken adhesive, match roll speeds

Glue Slinging / Splashing:

• Cause: Viscosity too low, roll speed too high

• Fix: Increase viscosity, reduce speed, check roll alignment

Poor Bond at Double Backer:

• Cause: Insufficient glue, adhesive too cold, wrong gel temperature

• Fix: Increase application, warm adhesive, check adhesive formula

Adhesive Compatibility:

Glue machine performance depends heavily on adhesive quality:

• Traditional starch glue: Requires 58-62°C gel temperature, steam-heated system

• Xuegong instant-setting adhesive: Works at room/low temperature, faster setting

• Alkali-free adhesive: Less corrosive to glue machine components

• Matched adhesive + equipment = optimal line performance

Optimization Tips:

• Use minimum glue needed for acceptable bond — saves cost and drying time

• Match adhesive type to line temperature capability

• Calibrate glue machines after every paper grade change

• Keep glue kitchen close to corrugating line to maintain temperature

• Train operators to recognize glue-related quality issues early

Xuegong provides matched adhesive systems designed for boiler-free corrugating lines. Contact us for glue machine optimization support and adhesive recommendations.