1. Challenges in bottom labeling and our automation solution

On a production line, labeling the bottom surface of products typically faces three problems: manually flipping workpieces takes time and effort and limits capacity; materials easily shake during bottom labeling, so labels are unevenly applied, with bubbles or wrinkles; and compatibility with products of different sizes is poor, making frequent changeover costly.

To address these pain points, inline equipment for labeling the underside of products was developed. Take the WZ-129 bottom labeling machine from Wanzhi Automation: its labeling head is mounted in a lowered position, so products traveling forward on the conveyor belt are labeled on the underside automatically, eliminating manual flipping entirely. This design simplifies the line layout, and the conveyor belt guides and positioning structures keep products centered through the labeling zone, solving misalignment structurally.

2. WZ-129 core technology

When selecting a labeling machine, core specifications directly determine line performance. The WZ-129 bottom labeling machine offers the following clear advantages in its technical design:

  • Wide throughput range: labeling speed is adjustable from 20 to 80 PCS/min, matching line pace for both small-batch sampling and high-volume continuous production.
  • Stable labeling accuracy: precise mechanical structure and belt positioning keep bottom labeling error strictly within ±1 mm, ensuring flat labels without wrinkles or offset.
  • High adaptability and customization: the standard model handles products up to 300 mm wide, and the conveyor width and positioning structures can be custom-built, with the conveyor widened and frame extended to suit workpiece size.

The machine also supports an integrated traceability approach: an optional coder or inline inkjet printer can print the production date, batch, and barcode at the same time as labeling. A separate touch-screen control panel makes label feed length, pressing pressure, and other parameters visually adjustable, and programs can be stored, greatly reducing changeover difficulty.

3. Selection criteria and applications for bottom labeling equipment

When selecting bottom labeling equipment, companies should focus on three aspects:

  • Material size and weight: assess the maximum length, width, and weight of the product and choose equipment whose conveyor width and load capacity match; if necessary, choose a model that supports custom widening.
  • Label material and traceability needs: if the label must carry variable data, confirm that the machine has mounting interfaces for a coder or inkjet printer so labeling and coding happen together.
  • Line integration: consider the frame material and how easy the machine is to move. The Wanzhi WZ-129, for example, uses a one-piece stainless steel frame with swivel casters, making it easy to deploy in the workshop and connect to an existing line.

The machine is widely used for bottom marking in food containers, household product cans, paper gift boxes, and wooden panels, and is an ideal replacement for manual work that improves packaging line efficiency.

FAQ

What should I do if labels always wrinkle during bottom labeling?

Wrinkling is usually caused by uneven pressing pressure or label material that is too soft. Adjust the pressing pressure parameter on the touch screen, or switch to a harder label material, and check the conveyor belt for wear.

Can the machine handle products of different sizes?

Yes. The standard WZ-129 handles products up to 300 mm wide, and the conveyor belt positioning structures are adjustable. For special sizes, ask the manufacturer about a custom widened and extended frame.

How can bottom labeling and date printing be done together?

The machine can integrate a coder or inline inkjet printer. Specify the coding requirements during selection, and the manufacturer will provide mounting positions above or beside the labeling mechanism so labeling and coding are completed in one pass.

Is changeover complicated when switching products?

The machine has a separate touch-screen control panel; labeling speed, label feed length, and other parameters can be switched and stored with one touch. When changing products, simply recall the matching program and fine-tune the mechanical guides.

Written by Wanzhi Automation