What Makes This Folder-Gluer Ideal for Bottom Lock Boxes?

You're running a corrugated box plant, and the orders for crash-lock bottom boxes keep growing. The challenge isn't just producing them—it's switching between bottom-lock and straight-line formats without losing half a shift to changeover. A folder-gluer for corrugated box that handles bottom-lock boxes efficiently needs dedicated hardware: a bottom-lock module that's quick to engage, folding belts that form the bottom accurately, and glue application that hits the right spots consistently. The AC SERIES from GK was designed with this specific capability in mind. This article examines the features that make this machine well-suited for bottom-lock box production—from the reversible bracket that speeds changeovers to the folding belts that keep bottom formation stable.

What Box Plant Operators Notice First

Two Observations on Bottom-Lock Production

Q: How does the machine handle the bottom-lock forming process?
A: The bottom-lock section features a board tracking structure with an upper gluer that makes bottom-locked boxes automatic gluing and forming. The bottom-folding speed is 50-200 pieces per minute, stable and reliable. The dedicated module handles the specific folding pattern required for crash-lock bottom boxes.

Q: What happens when I need to switch from bottom-lock to straight-line boxes?
A: The bottom-lock section is installed on a reversible bracket, substantially reducing swap adjustment time. The left and right baffles can be adjusted up and down to shorten adjusting and carton changing time. Changeovers that used to take an hour can be completed in minutes.

The Reversible Bracket — The Key to Fast Changeovers

The bottom-lock section distinguishes the AC SERIES from standard folder-gluers. It features a board tracking structure with an upper gluer that makes bottom-locked boxes automatic gluing and forming. The entire bottom-lock part is installed in a reversible bracket.

What the Reversible Bracket Actually Saves

Instead of removing and reinstalling an entire bottom-lock assembly—which involves unbolting components, realigning sections, and testing the setup—the reversible bracket lets you flip or reposition the module quickly. This is a practical design choice that reduces downtime between production runs, especially when you're switching between bottom-lock and straight-line boxes.

Baffle Adjustments That Cut Changeover Time

The left and right baffles can be adjusted up and down to shorten adjusting and carton changing time. These aren't adjustments that require specialized tools or lengthy procedures—they're designed for quick, tool-free repositioning.

Forming Bottom-Lock Boxes at Speed

Bottom-folding speed is 50-200 pieces per minute, stable and reliable. The bottom-lock module is supported by the same folding belts and drive system that handle the rest of the box, ensuring consistent performance.

Why Stability Matters at Higher Speeds

At 200 pieces per minute, you're processing over 3 boxes every second. The bottom-lock module's stable, reliable operation is critical—a single misfeed or mis-fold at that speed creates a cascade of waste. The AC SERIES's bottom-lock section delivers consistent results across the speed range.

Upper Gluer for Precise Adhesive Placement

The upper gluer applies adhesive exactly where it's needed for the bottom-lock pattern. Unlike manual gluing or less precise systems, the upper gluer ensures consistent glue placement from box to box.

Feeding and Folding That Support Bottom-Lock Production

The AC SERIES's feeding and folding sections are designed to support bottom-lock production without compromising performance on other box types.

Feeding That Prevents Skewing Before Bottom Forming

The feeding section is equipped with air suction function and a multi-stage rail to ensure the verticality of the pressing board. Skewed feeding is the most common cause of bottom-lock failures—if the sheet enters off-angle, the bottom won't fold correctly. The feeding section prevents this from happening.

Folding Belts That Keep the Bottom Forming Correctly

The folding section is equipped with driving belts that have a corrective function and extension work, making box forming more stable. This corrective function is particularly valuable for bottom-lock boxes, where the bottom folding pattern requires precise alignment.

Gluing — Water-Base Cold Glue for Reliable Bonding

The AC SERIES uses water-base cold glue for box assembly. The lower gluing tank feeds the upper gluer, and the paper collection section adopts a cylinder pressure system that makes it easier to adjust pressure and ensures more effective gluing.

Cold Glue and Corrugated — A Proven Combination

Water-base cold glue has been the standard for corrugated box production for decades. It bonds well to corrugated materials, dries without heat, and is compatible with the paperboard and corrugated grades the machine processes. Simple, reliable, and cost-effective.

One-Touch Pneumatic Pressure Adjustment

The transmission press is equipped with one-touch pneumatic pressure adjustment, making operation easy. The press has two functions: a waiting state that activates when feeding is paused, and a travel switch that pauses the machine in case of wrong collecting.

Specifications That Match the Box Types

Box Types That Benefit from the AC SERIES

The AC SERIES is designed for corrugated box plants that produce multiple box types:

Crash Lock Bottom Boxes

The primary application. The AC SERIES's bottom-lock module, reversible bracket, and upper gluer make it well-suited for crash-lock bottom box production. Dimensions range from 280mm to 1500mm across the three models.

Straight-Line Boxes

For standard straight-line boxes, the AC SERIES delivers high-speed performance without the bottom-lock module interfering. Models cover widths from 250mm to 1600mm.

Double Sided Boxes

The machine also handles double-sided box formats, with width ranges from 250mm to 1350mm.

Straight Answers on Bottom-Lock Folder-Gluers

Q: What makes the AC SERIES suitable for bottom-lock boxes?
A: The dedicated bottom-lock section with board tracking structure, upper gluer, and reversible bracket for fast changeovers.

Q: How fast does the bottom-lock section run?
A: Bottom-folding speed is 50-200 pieces per minute, stable and reliable.

Q: How does the machine handle changeovers from bottom-lock to straight-line?
A: The bottom-lock section is installed on a reversible bracket, substantially reducing swap adjustment time. Baffles can be adjusted up and down to shorten changeover time.

Q: What materials does the machine process?
A: The machine processes cardboard from 210-800g and A/B/E corrugated.

Q: What models are available?
A: The AC SERIES is available in three models: GK-1200AC, GK-1450AC, and GK-1600AC.

Request a Configuration for Your Box Line

A folder-gluer for corrugated box that handles bottom-lock boxes efficiently requires more than just speed—it needs a dedicated bottom-lock module, fast changeover capability, and consistent forming and gluing. The AC SERIES delivers all three: a reversible bracket that cuts changeover time, an upper gluer for precise adhesive placement, and bottom-folding speeds of 50-200 pieces per minute.

Whether you're producing crash-lock bottom boxes, straight-line boxes, or double-sided boxes, the AC SERIES offers the flexibility and reliability that corrugated box plants need. The three model options let you match the machine to your box width requirements.

Contact the manufacturer for a configuration assessment → their team can help you select the right model for your specific box types and production targets. Get a folder-gluer that makes bottom-lock production look easy.