The horizontal plywood board joining machine is specially designed for the raw material optimization link in plywood production. It realizes the joining of narrow-width veneers along the direction perpendicular to the veneer grain (i.e., the horizontal direction). Its core function is to join scattered narrow-width plywood core veneers, face veneers and back veneers into large-format boards with uniform width. 

It is suitable for the pre-processing needs of various products such as blockboard, ecological board, decorative veneer board and multi-ply plywood. As a key equipment to solve the problems of low utilization rate of narrow materials and reduce raw material waste, it provides wide-format qualified base materials for the subsequent vertical board joining and pressing processes.

Known as the "Raw Material Optimization Hub" in plywood production, the horizontal board joining machine realizes raw material value enhancement through narrow material joining, thereby reducing enterprises' raw material procurement costs. Meanwhile, it replaces traditional manual board joining with automated production, reducing labor input by over 80%, significantly improving production efficiency and board specification consistency. 

It forms a coordinated operation mode of "first horizontal joining for width expansion, then vertical joining for length extension" together with the vertical board joining machine, providing core support for plywood enterprises to achieve large-scale and standardized production.

I. Raw Material Preprocessing and Sorting Stage

The core of this stage is to realize the standardized classification of narrow materials, laying a foundation for multi-channel synchronous feeding. Different from the single linear feeding preparation of vertical board joining machines, this stage emphasizes "narrow material grading" more:

1. Narrow Material Screening and Specification Grading

Select narrow veneers (width 50-300mm, thickness 0.8-5.0mm) after peeling and drying, control the moisture content at 9%-13% (to meet the curing requirements of adhesives), and the thickness deviation shall not exceed ±0.2mm. After removing defects such as knots, insect infestations and cracks on the veneer surface, classify the veneers into 3-5 grades according to width specifications (e.g., 50-100mm, 100-150mm, etc.). Veneers of the same grade are placed into the same feeding channel to avoid joining misalignment caused by excessive width differences.

2. Grain Calibration and Front-Back Distinction

With the assistance of manual work or an intelligent grain recognition system, ensure that the grain direction of each veneer is perpendicular to the horizontal joining direction of the equipment (i.e., the grain extends vertically). At the same time, distinguish the front and back of the veneer to ensure consistent grain and uniform appearance of the joined board. For thin face veneers (thickness ≤1.5mm), use a soft conveyor belt for transportation to prevent damage during handling.

3. Equipment Debugging and Parameter Matching

Set parameters through the PLC control system according to the target wide board size (e.g., 1220mm, 1525mm) and veneer grade: ① Single-channel feeding speed: 20-25m/min (multi-channel synchronous linkage); ② Glue application amount: 120-180g/㎡ (reduce glue overflow for narrow material joining, and appropriately increase for softwood); ③ Rolling pressure: 15-20T (adjust according to veneer thickness, reduce pressure for thin materials); ④ Finished product width error: ≤±0.5mm. Inspect the CCD visual positioning system, multi-channel synchronization mechanism and glue circuit system to ensure stable equipment operation.

II. Core Horizontal Joining Stage (Multi-Channel Collaboration)

This stage is the core of horizontal board joining. Different from the "continuous single-material joining" of vertical board joining machines, it adopts the "multi-material synchronous feeding-parallel joining" mode to realize the efficient conversion of narrow materials into wide boards:

1. Multi-Channel Synchronous Feeding and Positioning

Feed narrow veneers of different grades into the corresponding feeding channels of the equipment respectively. Each channel is equipped with an independent photoelectric sensor and servo positioning mechanism to detect the edge position and length of the veneer in real time. The CCD visual system performs global positioning on the multi-channel veneers to ensure that the joining end faces of veneers in adjacent channels are aligned, the butt gap is ≤0.2mm, and the overall width meets the target specification.

2. Edge Trimming and Precision Gluing

The aligned narrow veneers enter the trimming station, where the high-speed rotating trimming knife performs slight cutting on the joining edges of the veneers (to remove burrs and correct bevels) to ensure the joining surfaces are flat and fit. Then they enter the gluing station, where adhesive is evenly applied to the horizontal joining sides of the veneers by means of "side rolling". The width of the glue layer is accurately matched with the thickness of the veneer to avoid adhesive contamination on the veneer surface.

3. Continuous Rolling Joining and Glue Layer Impregnation

Multiple glued narrow veneers are synchronously fed into the continuous rolling mechanism, and the upper and lower rollers apply uniform pressure (15-20T) to press the veneers tightly. During the rolling process, the adhesive fully impregnates the veneer fibers, and the excess adhesive is discharged through the side guide grooves. The joining pressure holding time is linked with the feeding speed (about 3-5 seconds per group) to ensure the initial curing of the glue layer and form a stable wide board blank.

4. Full-Width Calibration and Defect Detection of Wide Boards

The joined wide board blank enters the calibration station. The equipment uses an infrared width gauge to detect the width of the board blank in real time. If there is a deviation, the PLC system immediately fine-tunes the feeding position of the edge channel. At the same time, the visual detection system scans the surface of the board blank to identify defects such as glue overflow and misalignment at the joining seam, marks the abnormal positions and feeds back to the control system for subsequent processing.

III. Finished Product Post-Processing and Connection Stage

This stage focuses on ensuring the stable quality of wide boards and providing qualified base materials for subsequent vertical board joining. The process emphasizes "wide board shaping" and "specification unification":

1. Initial Curing and Surface Cleaning

The wide board blank is transported to the curing area via the conveyor belt, and the glue layer curing is accelerated through normal temperature ventilation or low-temperature drying (40-50℃). The curing time is about 8-12 minutes (adjust according to the adhesive type). After curing, the automatic grinding mechanism slightly grinds the surface of the board blank and the joining seam to clean up residual glue and burrs, ensuring the surface flatness is ≤0.6mm.

2. Precision Cutting and Quality Inspection

According to production needs, the board blank enters the fixed-length cutting station, where the horizontal cutting knife cuts it into boards of standard width (e.g., 1220mm) with a cutting precision of ±0.3mm and a vertical burr-free cut surface. Quality inspectors focus on testing: ① Joining seam: no gaps, no cracks, no glue overflow, width ≤0.2mm; ② Dimensional accuracy: width and thickness meet the standards; ③ Appearance: consistent grain, no surface damage. Unqualified products are marked and returned to the raw material area for reprocessing.

3. Graded Stacking and Process Connection

Qualified boards are stacked by thickness and grade, with a stacking height ≤1.2m (to prevent deformation due to stress on the middle of the wide board). A moisture-proof pad is laid at the bottom, and the boards are stored in a well-ventilated and dry workshop area. Then, according to the production plan, the wide boards completed by horizontal joining are transported to the vertical board joining machine station for lengthwise joining, forming a continuous production process of "horizontal joining for width expansion, vertical joining for length extension".

IV. Equipment Cleaning and Process Review