Terrazzo tile production quality control and maintenance guide

Terrazzo tile production quality control and maintenance guide with automatic terrazzo tile making machine

This is for the guide to make terrazzo tiles by automatic terrazzo tile making machine, the raw material and curing process.

1. Raw material selection
 

• Aggregate : Choose marble, quartz or glass particles with high hardness and uniform color. The particle size needs to be graded and screened (0.5-8mm is recommended) to ensure that there are no impurities and the dust content is less than 2%.
• Cement : Use Portland cement of grade 42.5 or above, fresh and free of lumps, and the color must be consistent with the design (e.g. white cement for light-colored terrazzo).
• Pigments : Alkali-resistant and weather-resistant inorganic mineral pigments, the dosage should not exceed 5% of the cement weight to avoid affecting the strength.
• Water : Clean tap water, pH value 6-8, oily or excessive chloride ions are strictly prohibited.

 

2. Ratio design

 

• Standard mix ratio : The ratio of cement to aggregate is usually 1:1.5~2.5 (adjusted according to the aggregate particle size), and the water-cement ratio is controlled at 0.3-0.35 to ensure that the slurry fully wraps the aggregate.
• Experimental verification : Test blocks shall be made for each batch to test the 7-day and 28-day compressive strength (≥30MPa) and surface gloss.

 

3. Mixing process

 

• Feeding sequence : first dry mix aggregate and cement for 1-2 minutes, then slowly add water and stir for 3-5 minutes until uniform.
• Uniformity control : Mixer speed ≥30r/min to avoid color difference or uneven distribution of aggregate.

 

4. Molding process

 

• Mold treatment : Use steel molds and apply a release agent (such as paraffin emulsion) to prevent sticking.
• Vibration compaction : Use a high-frequency vibration table to vibrate for 20-30 seconds to eliminate bubbles and ensure that the edges and corners are fully filled.
• Thickness tolerance : single brick thickness deviation ≤±1mm, diagonal error ≤2mm.

 

5. Treatment before initial setting

 

• Surface smoothing : Use a trowel to smooth the surface 2-3 times before initial setting to eliminate surface pores.
• Anti-cracking measures : When the ambient temperature is higher than 30℃, cover with a wet cloth to prevent the water from evaporating too quickly.

 

 

2. Maintenance process specifications

 

1. Pre-curing after demoulding

 

• Standing time : demould within 24 hours after molding to avoid damaging the edges and corners.
• Environmental conditions : temperature 20±5℃, humidity ≥80%, avoid direct sunlight or strong wind.

 

2. Wet curing stage

 

• Standard curing : Cover with wet sacks or plastic film immediately after demoulding, and continue watering for 7 days, 3-4 times a day (increase to 5-6 times in summer).
• Water temperature control : In winter, the water temperature needs to be close to the brick temperature (temperature difference ≤ 10°C) to prevent thermal stress cracking.

 

3. Dry curing stage

 

• Natural drying : After wet curing, move to a ventilated and cool place and dry naturally for 21 days, keeping the humidity at 50%-60%.
• Stacking requirements : Use “well” shaped stacking, with ≤5 layers, and separate the layers with wooden strips.

 

 

3. Common Problems and Solutions

 

question	Cause Analysis	Improvement measures
Surface alkali	Free CaO precipitation in cement	Use low-alkali cement to increase the sealing performance during the curing stage
Corner damage	Demolding too early or vibrating insufficiently	Extend demoulding time to 48 hours, strengthen

 

3. Common Problems and Solutions

 

question	Cause Analysis	Improvement measures
Surface alkali	Free CaO precipitation in cement	Switch to low-alkali cement, increase cover sealing during the curing phase, and pre-treat aggregates with waterproof coatings.
Corner damage	Demolding too early or vibrating insufficiently	Extend the demoulding time to 48 hours, strengthen vibration compaction, and check the flatness of the mold edge.
Obvious color difference	Uneven pigment dispersion or aggregate batch differences	Extend the dry mixing time to 3 minutes, strictly use homogeneous aggregates in batches, and clean the mixer regularly.
Insufficient strength	Water-cement ratio is too high or curing humidity is insufficient	Reduce the water-cement ratio to below 0.3 and use a spray system to maintain a constant wet curing environment.
Surface cracks	Drying too fast or temperature stress	Extend wet curing to 10 days. During the drying stage, control the ambient humidity to ≥50% and avoid exposure to sunlight.
Too many pores	Insufficient vibration time or poor slurry fluidity	Increase the vibration time to 40 seconds, optimize the water-cement ratio and add water reducer (dosage 0.5%-1%).
Uneven gloss	Inconsistent grinding process parameters	The grinding machine speed is unified (300-400r/min), and the process is divided into two stages: coarse grinding and fine grinding.
Demolding adhesion	Uneven or ineffective application of release agent	Use water-based release agent, clean and re-apply the mold every shift, and avoid storing the mold at high temperatures.

 

IV. Quality Inspection and Acceptance Standards

 

1. Test items and methods

 

• Compressive strength : 28-day strength test according to GB/T 17671 standard, ≥30MPa is qualified.
• Water absorption rate : weigh after boiling in boiling water for 3 hours, water absorption rate ≤6%.
• Wear resistance : Tested according to GB/T 3810.6, the depth of wear pit is ≤2mm.
• Dimension deviation : measured with a vernier caliper, length/width error ≤±1mm, thickness error ≤±0.5mm.
• Appearance defects : no cracks or missing corners when visually inspected, color difference ΔE≤2.0 (detected by colorimeter).

 

2. Sampling rules

 

• From every batch of 5,000 pieces, 10 pieces are randomly selected for destructive testing and 20 pieces for appearance testing.
• If the unqualified rate is greater than 5%, the entire batch will be reworked or downgraded.

 

 

V. Packaging, transportation and storage specifications

 

1. Packaging requirements

 

• Wooden pallet + wrapping film fixed, and foam corner protectors added.
• No more than 80 pieces should be stacked per pallet, marked with production date, batch and strength grade.

 

2. Transportation precautions

 

• The vehicle floor should be flat and secured with straps after loading. The speed limit should be ≤ 60km/h to avoid bumps.
• In the rainy season, the goods must be covered with rainproof cloth, and transportation is stopped in winter when the temperature is below -5℃.

 

3. Storage conditions

 

• The warehouse environment should be dry (humidity ≤ 70%), and the materials should be stacked 20cm above the ground. Contact with chemicals is prohibited.
• The storage period shall not exceed 6 months and shall follow the “first in, first out” principle.

 

 

 

6. Equipment maintenance and process optimization suggestions

 

1. Maintenance of key equipment

 

• Mixer : Clean residual slurry daily and add high-temperature grease to the bearings every month.
• Vibration table : Check the tightness of the eccentric block bolts and calibrate immediately when the amplitude deviation is greater than 10%.
• Grinding machine : Diamond grinding discs are replaced every 2,000 pieces, and the pH value of cooling water is kept neutral.

 

2. Process Optimization

 

• Automatic maintenance system : install temperature and humidity sensors + automatic sprinkler device to reduce manual errors.
• Aggregate premix technology : Aggregate packages are pre-formulated according to particle size and color to improve mix consistency.

 

 

 

VII. Conclusion

 

By strictly controlling the raw material ratio, optimizing the maintenance process and regularly maintaining equipment, the yield and durability of terrazzo tiles can be significantly improved. It is recommended that companies establish digital production files to record the parameters of each batch in real time to provide a basis for quality traceability. If there are special environmental requirements (such as high-cold and saline-alkali areas), the formula and maintenance plan need to be adjusted accordingly.

 

 

 

Appendix: Terrazzo Tile Maintenance Periodic Table

 

stage	time	Temperature and humidity requirements	Operation points
Pre-curing	1-2 days	20±5℃, humidity ≥80%	Cover with a damp cloth and do not move
Wet curing	7-10 days	15-30℃, humidity ≥90%	Spray water 4 times a day for even penetration
Dry curing	21-28 days	Natural ventilation, humidity 50-60%	Avoid stacking and check regularly

 

 

 

This guideline is compiled in combination with industry standards and practical experience, and needs to be flexibly adjusted according to specific production conditions during implementation. It is recommended to hold a quality analysis meeting every quarter to continuously improve the process.