Product Introduction

The Square sheet former, also known as a square handsheet machine or square paper former, is a dedicated laboratory device for preparing square pulp handsheets. It uses the vacuum generated by a large-diameter quick-release drain valve for forming, assisted by a high-vacuum oil-free pump, to produce square sheets measuring 200 mm × 200 mm from fiber slurries. The equipment offers both bubble mixing and manual mixing modes, suitable for forming ultra-thin, ultra-thick, and ultra-fine fibers. Built entirely from 304 stainless steel, it features a white-water recirculation system, electric water fill, and pneumatic automatic drainage. A flatbed sheet dryer can be paired for rapid drying. It is widely used in paper industry research, pulp evaluation, and paper property testing.

Key Features
Square Large-Size Forming: Effective sheet size 200 mm × 200 mm, with optional 250 mm × 250 mm, meeting varied specimen size requirements for different tests.
Dual Mixing Modes: Standard bubble mixing and manual mixing. The pneumatic mixing disc features precision-drilled holes with uniform circumferential spacing and scientifically calculated apertures for optimal air flow.
Rapid Vacuum Filtration: Utilizes vacuum from a large-diameter quick-release drain valve plus an oil-free high-volume vacuum pump for efficient dewatering, with high suction and no oil maintenance.
304 Stainless Steel Construction: Entire machine built from 304 stainless steel, durable, aesthetically pleasing, non-staining, and easy to clean.
White Water Recirculation: Equipped with white-water recirculation and electric water fill; includes a water inlet for external supply and a stainless-steel jet pump for water reuse.
Pneumatic Automatic Drainage: Pneumatically actuated automatic drainage avoids the slow drainage of small-bore solenoid valves and the inconvenience of manual draining.
Viewing Window: Water tank includes a viewing window for controlling water release volume, enabling precise adjustment of sheet bulk.
Broad Applicability: Suitable for various paper and board sheet forming, as well as teaching and research applications across different fiber types.

Technical Specifications

FAQ
I. Pneumatic Bubble Mixing Issues
1. Weak bubbles, insufficient stirring, fibers not dispersing
Insufficient air pressure, air hose leak, or clogged mixing holes. Adjust pressure to 0.4-0.6 MPa; check for hose leaks; remove mixing disc and clear holes with clean water.
2. Localized dead spots, uneven mixing
Uneven clogging of air holes or misaligned mixing disc. Thoroughly clean disc; reposition and lock it flat.
II. Drainage Issues
1. Slow pneumatic drainage, poor flow
Pipes clogged with fibers, pneumatic valve sticking, or debris obstruction. Disassemble and clean drain pipes; clear valve body debris; lubricate valve core.
2. Drain valve won't fully close, continuous seepage
Worn gasket or fibers trapped on sealing surface. Clean sealing surfaces; replace waterproof gasket.
III. Vacuum Filtration Issues
1. Low vacuum, slow dewatering
Oil-free pump suction loss, line leaks, or seal leaks. Check and tighten upper/lower cylinder seals; tighten vacuum line connections; clean pump intake filter.
2. Noisy vacuum pump, suction loss
Dust or water ingress, clogged filter. Clean intake filter cotton; keep pump dry; prevent water backflow.
IV. Sheet Formation Issues
1. Uneven sheet thickness, one side thicker
Machine not level, drainage too fast, or fiber flocculation. Level the machine feet; let stock rest briefly after mixing before draining; thoroughly disintegrate fibers.
2. Pinholes or small holes in sheet
Damaged stainless steel forming wire or dirty wire surface. Clean forming wire; replace with new papermaking-grade wire if damaged.
3. Sheet sticking to wire, difficult to peel
Residual pulp on wire surface or excessive dewatering. Rinse wire thoroughly after each use; control filtration time—release sheet at about 80% dryness.
V. Water Recirculation / Electric Fill Issues
1. Jet pump not filling or filling slowly
Insufficient water supply, clogged inlet, or air in pump. Clean inlet filter; purge air from lines; check external water supply.
2. Recirculation flow obstructed
Fiber buildup in recirculation piping. Periodically disassemble and flush recirculation pipes.
VI. Water Leakage Issues
1. Leaks at upper/lower water tank joint
Aged center gasket or uneven tightening. Replace with 304-compatible silicone gasket; tighten clamps/bolts diagonally and evenly.
2. Leaks at fittings and hose connections
Loose fittings or aged hoses. Tighten clamps; replace deteriorated water hoses.

After-Sales Service
Thank you for your inquiry. Shandong Annimet Instrument Co., Ltd., established in 2007, has dedicated nearly two decades to the R&D, production, and sales of quality testing instruments. We regard product quality as the lifeblood of our enterprise and pursue excellence in every product developed. Looking back at the history of scientific and technological development, we firmly believe that every product is born from technological advancement, every technology derives from material exploration, every material discovery depends on process improvement, and every process improvement relies on experimental support. Humanity never lacks ideas; we need the means to realize them. Annimet Instrument will consistently provide the tools for your ideas and creativity. Should you have any questions, please feel free to contact our customer service team—we are fully committed to providing excellent pre-sales, in-sales, and after-sales service.