Is a Crash-Lock Bottom Folder-Gluer the Right Choice for Your Carton Line?

You're running a folding carton production line — food boxes, pharmaceutical packaging, cosmetic cartons, or stationery boxes. The bottom needs to lock securely, the folds need to be precise, and the output needs to be fast enough to meet orders without compromising quality. A folder-gluer for cardboard box with crash-lock bottom capability is designed for exactly this purpose — feeding flat carton blanks and transforming them into finished, folded, and glued boxes in one continuous, automated flow. The GK-CB is a 4-fold bottom-lock folding-gluing machine that handles cardboard from 210-800g, reaches speeds up to 220 meters per minute, and delivers bottom folding at 50-200 boxes per minute. This guide covers what a crash-lock bottom folder-gluer does, the key technologies that make it work, and what to look for when selecting one for your carton production line.

Four Folds, One Pass – The Complete Crash-Lock Bottom Forming Process

A crash-lock bottom folder-gluer takes flat carton blanks and transforms them into finished, folded boxes with locked bottoms in one continuous process. The machine performs four folds: fold 1 and fold 3 are folded 180°, while fold 2 and fold 4 are folded 90° and 180° sequentially. The bottom is then glued and locked in place. The GK-CB uses synchronous belt transmission and electronic continuously variable speed control, with domestically sourced standard electronic components. The feeding section uses mechanical continuously variable control, making it stable and easy to operate. The machine is widely used in food, medicine, cosmetics, stationery, and other ordinary carton applications.

The Folding Sequence

The machine performs a precise sequence of folds: fold 1 and fold 3 are folded 180°; fold 2 and fold 4 are folded 90° and 180°. This sequence creates the crash-lock bottom that locks securely without additional fasteners.

Bottom Gluing and Locking

After folding, the bottom is glued using water-based cold glue and locked into place. The result is a box that stays folded and locked, ready for filling and shipping.

220m/min, 50-200 Boxes/min, and 6.0kW – The Numbers That Define Performance

The GK-CB series delivers a maximum line speed of 220 meters per minute. Bottom folding speed ranges from 50-200 boxes per minute, stable and reliable. Both models are powered by 6.0kW at 380V. The machine handles cardboard from 210-800g. The folding section length is 1392mm with 135° folding capability.

Speed and Output Flexibility

The 50-200 boxes/min range allows you to match production speed to material and complexity — slower speeds for intricate designs or heavier board, faster speeds for high-volume runs of standard boxes.

Board Weight Range

The 210-800g range covers most standard carton board applications — from lightweight pharmaceutical packaging to heavier food and cosmetic cartons.

Pre-Folding at 90° and 180° – The Feature That Makes Auto Packaging Possible

The pre-fold section is a key differentiator of the GK-CB series. It applies a double-board structure with a set of pre-folding knives. The pre-fold angle reaches 180° and 90°, making it especially suitable for small but high cartons and delivering more satisfactory results during rapid prototyping. This pre-folding capability is essential for automatic packaging applications.

Why Pre-Folding Matters

Pre-folding creates creases that guide the final folds, reducing stress on the board and preventing cracking. This is particularly important for high-speed production where the board is folded rapidly.

Benefits for Small, High Cartons

The pre-fold section is especially effective for small but high cartons. These cartons are more challenging to fold without cracking, and the pre-fold knives ensure clean, consistent folds.

Three-Board Tracking with Upper Gluer – The System That Delivers Stable, Reliable Bottom Locking

The bottom-lock section uses a three-board tracking structure with an upper gluer that enables automatic gluing and forming of bottom-locked boxes. The entire bottom-lock part is installed in a reversible bracket, which substantially reduces the swap adjustment time between bottom-fold boxes and other box types.

Quick Changeover Between Box Types

The reversible bracket design allows operators to switch between bottom-fold boxes and other box types quickly. This reduces downtime and increases production flexibility.

Special-Shaped Carton Capability

The bottom-lock section can also be used for special-shaped cartons, expanding the machine's application range beyond standard rectangular boxes.

210-800g Cardboard – One Machine That Covers the Full Range of Carton Board

The GK-CB series handles cardboard from 210-800g. This range covers most standard carton board applications — from lightweight pharmaceutical packaging to heavier food, cosmetic, and consumer goods cartons. The machine's feeding section uses 5 adjustable feeding belts to ensure easy adjustment, stable, and smooth feeding.

Lightweight Board Applications

For lightweight board (210-350g), the machine runs at higher speeds with standard settings. These applications include pharmaceutical cartons, inserts, and lightweight packaging.

Heavyweight Board Applications

For heavier board (350-800g), the machine adjusts to ensure clean folds without cracking. These applications include food cartons, cosmetic packaging, and premium consumer goods packaging.

GK-650CB or GK-780CB – Choose the Width That Matches Your Carton Requirements

The GK-CB series is available in two models to match different production requirements:

Matching Width to Production Requirements

The GK-650CB handles carton widths from 75-650mm, making it suitable for standard carton sizes. The GK-780CB handles widths from 75-780mm, providing capacity for larger cartons.

Consistent Performance Across Models

Both models share the same speed range, board weight range, and power requirements. The primary difference is the maximum carton width and machine footprint.

What Production Managers Ask About Folder-Gluers

What is the maximum line speed of the GK-CB series?
The GK-CB series delivers a maximum line speed of 220 meters per minute.

What is the bottom folding speed?
Bottom folding speed ranges from 50-200 boxes per minute, stable and reliable.

What materials can the machine handle?
The GK-CB series handles cardboard from 210-800g.

What are the available width options?
The GK-CB series is available in two models: GK-650CB (650mm width) and GK-780CB (780mm width).

What are the key features of the machine?
Key features include 4-fold bottom-lock, pre-fold section (90° and 180°), three-board tracking bottom-lock with upper gluer, 5 adjustable feeding belts, one-touch pneumatic knife, and a reversible bracket for quick changeover between box types.

Get a Folder-Gluer That Matches Your Carton Types and Volume Targets

Selecting a folder-gluer for cardboard boxes comes down to three factors: width (match your carton size), speed (match your throughput), and board weight range (match your material specifications). Contact the manufacturer for a customized quote → —their team can help you select the right GK-CB configuration for your specific carton production needs.

The GK-CB automatic crash-lock bottom folder-gluer is designed for folding and gluing 4-fold bottom-lock cartons. It handles cardboard from 210-800g, delivers a maximum line speed of 220m/min, and achieves bottom folding speeds of 50-200 boxes per minute. Available in GK-650CB and GK-780CB models with 6.0kW 380V power, the machine features pre-fold section (90° and 180°), three-board tracking bottom-lock with upper gluer, 5 adjustable feeding belts, and a reversible bracket for quick changeover. Applications include food, medicine, cosmetics, stationery, and other ordinary cartons. The manufacturer provides comprehensive technical support, installation guidance, and after-sales service. Connect with them to discuss your carton size requirements, production volume targets, and material specifications.