​The core difference between loop mold bags and filter point mold bags​​

The core difference between loop mold bags and filter point mold bags

Both are geoforming bags used for pumping concrete/mortar molding, but there are essential differences in the thickness formation mechanism, appearance and pore characteristics, construction pump pressure and loss, and typical applications.

Structure and forming mechanism

Height-setting ropes (looping ropes) are set at a certain distance between the upper and lower layers of woven fabrics. After filling, the fabric is "propped up" to form a panel of uniform thickness; typically a "double-layer four structure", the height-setting ropes are often arranged in a crisscross pattern, and the thickness is controlled by the length of the height-setting ropes.

Tiny filter points (reverse filter and drainage points) are set on the cloth surface according to the designed spacing. After filling, the slurry is extruded from the filter points to form a panel with a regular "lattice"; it is a reverse filter and drainage type structure of the mold bag

Molding effect and application

Uniform thickness and good panel integrity, suitable for slope protection/lining with high requirements on flatness and thickness control

Fast molding and strong on-site adaptability; often used for large-area slope protection, but the thickness control and flatness requirements are not as strict as those for circle mold bags

Typical applications

River, lake and sea dam slope protection/bank protection, panel projects requiring more precise thickness

Large-area slope protection and rapid construction scenarios such as river embankments, channels, and ponds

The above definition, structure and mechanism come from the engineering description and construction points of the mold bag (also known as the loop mold bag/geotube bag) and the "reverse filter drainage point" mold bag

How to choose

For slope protection projects that require strict control over panel thickness uniformity and linearity/flatness, circle forming bags are preferred.

For large-area slope protection that pursues rapid prototyping, has long pumping distances, or requires the use of filter points to achieve more stable slurry discharge, filter point mold bags can be given priority.

If on-site mixing and pumping conditions are limited (such as mixing plant capacity, pumping distance/height difference is large), test pumping and filling should be carried out based on the slump of the mixture, aggregate particle size and equipment capacity, and then finalized.

Differences in construction points (for reference when comparing and selecting plans)

Loop mold bag

Laying: Set positioning stakes and tensioning devices with a spacing of 1 to 2 m and no less than 4 pieces per piece; press sand bags/gravel bags while paving. Sand and gravel bags should be tied in series in windy and wave areas, with a spacing of generally 1 to 2 m. Adjacent mold bags are sewn together with double strands, and a geotextile filter layer is laid at the bottom of the seam. The overlap width is not less than 50 cm.

Filling: Suitable for continuous operation; conventional control indicators are slump of 18 to 20 cm and maximum particle size of stones about 20 mm; when filling is almost full, pause for 5 to 10 minutes and wait for bubbles to precipitate before filling again; the filling speed is usually controlled at about 10 to 15 m³/h in engineering, and the filling pressure is determined by the equipment and on-site test pump

.

Filter point mold bag

Mix ratio and pumping: In order to ensure smooth "squeezing" molding, the mixture needs to have high fluidity/good pumpability; in engineering, the slump is usually about 18-20 cm, and the maximum particle size of the stones is about 20 mm; the pump pressure and flow rate need to be determined through test pump-test filling to prevent blockage of the filter point or local segregation.