By Application
Stackers for the Green End of the Sawmill
Lumber leaving the trim saw is wet, rough, and needs stickers between every course so air can circulate through the kiln package. GBI has built green-end stackers for sawmills of every size and species — from high-volume softwood lines running 500,000 board feet a shift to hardwood mills that demand careful, precise handling of dense and expensive material.
The Green-End Job
Why the Stacker Is the Critical Machine
At the green end of a sawmill, the stacker sits between the trim saw and the kiln. Its job is to build uniform lumber packages with stickers accurately placed between each course — creating the airflow gaps the kiln needs to dry lumber evenly. Sticker position, spacing, and course alignment all affect how the package dries. A stacker that places sticks inconsistently produces packages with hot spots, cold spots, and increased drying defects.
GBI has been engineering green-end stackers since 1981. The result is a machine line built specifically for this application: accurate stick placement at high throughput, minimal operator involvement, and service lives routinely reaching 25 years on the mill floor.
Selecting the Right Stacker for Your Mill
- Throughput
- Above ~100,000 board feet per shift → automatic stick placing. Below → manual stick placing typically fits.
- Species
- Softwood (pine, spruce, fir, stud mills) → high-throughput automatic. Hardwood (oak, walnut, cherry) → manual or automatic depending on volume.
- Board dimensions
- Dimensional lumber (uniform width) or random width — GBI stackers handle both. Min/max length and package width determine frame sizing.
- Sticker size
- Stick dimensions drive magazine and distribution chain design. Confirm sticker spec early in the conversation.
Stacker Options for Sawmills
Choose the Right Stick-Placing Approach
Automatic Stick-Placing Stacker
GBI's VPG Automatic Stick-Placing Stacker automates the entire stacking and stickering cycle. The operator monitors; the machine places every stick and builds every course without manual intervention. Designed for the sustained high-volume production rates of softwood sawmills and stud mills.
- Patented Variable Pan Geometry (VPG) — reduces pan travel distance, enabling higher BPM at the same mechanical speed
- Fastack frame minimizes mechanical motion per cycle — lower wear, longer service life
- Single-man operation — no secondary attendant required at full production throughput
- No scheduled preventive maintenance program required
- Third Generation controls: crash prevention, stick-in-pan verification, auto-cycle, remote diagnostics
- 25-year typical service life
Softwood and stud mill green ends above ~100,000 board feet per shift. Also the standard choice for treating plants — see Treatment Plants.
Automatic Stick-Placing Stacker — Full Details →Manual Stick-Placing Stacker
GBI's manual stick-placing stacker automates the stacking cycle while the operator places stickers by hand. Hardwood mills typically run at lower board-feet throughput — the raw material is denser, higher-value, and handled more deliberately. Manual stick placing fits this pace and keeps capital cost in proportion to production volume.
- Automated stacking cycle — operator is not involved in every board movement
- Manual sticker placement — operator positions each sticker at their pace
- Configurable for random-width hardwood packages as well as dimensional lumber
- Right-sized for mills where the operational profile favors manual sticking
- Same hydraulic ruggedness and GBI build quality as the automatic line
Hardwood mills of any size. Softwood and stud mills below ~100,000 board feet per shift where the operational profile favors manual sticking.
Manual Stick-Placing Stacker — Full Details →Green-End Mill Workflow
Where the Stacker Fits in the Line
Log Deck & Debarker
Logs are debarked and fed into the primary breakdown saws.
Saws, Trimmer & Sorter
Rough lumber is cut, trimmed, edged, and sorted by length and grade downstream of the primary saws.
Infeed Transfer & Unscrambler
Lumber is transferred to the stacker bay, unscrambled into even-ended courses, and presented to the stacker infeed.
Stacker with Stick Placing
The GBI stacker builds kiln packages with accurate sticker placement between each course. Packages leave on outfeed transfer chains.
After the stacker, packages go to the kiln. Post-kiln, lumber moves to the dry-end planer mill — where a separate solid-pack stacker handles packaging without stickers. See Dry-End Planer Mill Stackers →
Supporting Equipment
Complete the Green-End System
Stick Feed & Collection
Stickers need to be loaded into the stacker magazine, collected from completed packages, and returned for re-use. GBI builds stick unscrambler systems, distribution chains, and collection loops sized to your stacker and throughput.
Stick Feed & Collection →Infeed & Outfeed Transfer
Transfer chains, roll cases, and incline conveyors connect the stacker to the sort deck upstream and the kiln transfer downstream. GBI engineers the full infeed and outfeed to match the stacker line.
Infeed & Outfeed Transfer →Breakdown Hoists
Tilt hoists break down unit packages arriving at the stacker infeed from the sort chain — destacking the unit so boards can feed the stacker as individual courses.
Breakdown Hoists →Tell Us About Your Mill
Species, throughput, board dimensions, and layout — GBI engineers the right stacker and support system for your green-end operation.
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