Adhesive Batch Preparation SOP: Standard Operating Procedure for Glue Kitchen

A glue-kitchen SOP converts a formulation into a repeatable, traceable adhesive batch. It controls material identity, weighing, water temperature, addition sequence, mixing energy, hold time, release tests, transfer, and cleaning. For simplified Easy Glue style preparation with /products/alkali-free-powder, fewer separate chemicals reduce complexity, but they do not remove the need for measurement or batch authorization.

Issue and Verify the Batch Card

The supervisor issues a controlled batch card showing recipe revision, batch size, destination tank, powder or starch lot, water quantity, target temperature, addition sequence, mix times, viscosity range, gel point where required, and maximum hold time. Two people should verify the recipe code before charging a 500 kg or larger batch.

Prepare the Mixer Safely

Confirm the mixer is clean, drained, guarded, and labeled for the selected recipe. Check valves, recirculation, dust extraction, and emergency stop before starting agitation. Follow adhesive-handling-safety-corrugating-plant for SDS access, eye protection, gloves, spill control, manual handling, and lockout; alkali-free does not mean hazard-free.

Calibrate Weighment and Volume

Verify scales against a known check weight at the start of each shift and record the result. Meter water by a calibrated load cell, flowmeter, or level-volume chart. For a 25 kg bag, reconcile full bags plus any partial quantity to within the approved tolerance, commonly ±0.5% for major ingredients and tighter where the formulation requires it.

Control Water Quality and Temperature

Measure process-water pH, hardness or conductivity on the defined schedule and log water temperature for every batch. A typical operating window may be 25–35°C, but the current product data sheet governs. Water at 10°C can delay hydration and change viscosity development; water above the approved range can create lumps or premature thickening.

Follow the Stein-Hall Sequence

For a conventional Stein-Hall system, prepare the carrier phase, allow controlled swelling, then add secondary water and raw starch in the validated order. Record each addition time and mixer speed. Never improvise caustic, borax, or starch quantities to chase one viscosity reading; a sequence error can change gel behavior even when the final cup time appears normal.

Prepare Alkali-Free Easy Glue Style Batches

For /products/alkali-free-powder, charge measured water, establish the specified vortex without drawing air, add powder steadily, and mix for the validated period. A typical guide may use a powder-to-water ratio around 1:3–1:4 and 15–20 minutes of mixing, but operators must follow the lot-specific technical sheet and approved plant trial.

Prevent Lumps, Dust, and Air Entrainment

Add powder below the dust-control hood and avoid dumping multiple bags at once. Keep the powder stream inside the moving liquid, not on a dry shaft or tank wall. If foam raises the apparent level by 10%, do not correct the batch with extra water; reduce air entrainment and test a settled sample.

Release Testing

After the specified mix and rest period, take a representative sample from a circulating line or approved point. Test viscosity using the named cup and temperature, inspect homogeneity, and measure solids, pH, or gel point where the recipe requires. Record the actual values rather than writing 'OK'; a result of 42 seconds is traceable, while a check mark is not.

Apply Hold-Time Limits

Mark the batch completion time and expiry time on the tank and production screen. Depending on formulation, temperature, hygiene, and recirculation, an approved hold limit may be 4–8 hours. Do not blend an expired heel into a fresh batch without a validated instruction, because age-related viscosity or microbial change becomes hidden.

Transfer and Line Clearance

Verify the receiving tank, route, valve lineup, filter condition, and available capacity before transfer. Pass adhesive through the specified screen and record transfer start and finish. Prevent cross-connection between recipes; even 50–100 kg of incompatible heel can shift a small batch outside its release range.

Batch Deviation Procedure

If water, powder, sequence, temperature, or test result is outside tolerance, place the batch on hold and notify the authorized owner. Corrections must use an approved calculation and be recorded as actual additions. Never add unmeasured water at the corrugator pan to hide an out-of-spec kitchen batch.

Planning, Cleaning, and Review

Use glue-kitchen-batch-planning-corrugator-guide to size batches against the next 2–3 hours of orders and avoid both shortages and aging surplus. At shift end, reconcile theoretical and actual usage, clean according to the sanitation schedule, and trend viscosity deviation, rejected batches, hold-time expiry, and kg/1,000 m². Xuegong New Materials Group can help validate water, batch cards, and operator training for /products/alkali-free-powder while the plant retains responsibility for local safety rules and final release limits.