April 01, 2020

Method for Repairing Glass Reinforced Septic Tank

Many customers say they don't know how to fix the problems of the glass reinforced plastic septic tank. With these problems, the Compression Resistance Fiberglass Septic Tank Exporter will answer the questions for customers.

1. Fabrication of unidirectional fiber composite material plate

The winding method is to make the fibers drawn from the creel go through the tensioner, the rubber trough, the yarn guide roller, and the wire winding nozzle, and then wind them to the surface of the core mold, and finally solidify and form. The standard stipulates that the size of the template is 270mmX270mm. The template can be wound to make two flat plates (front and back) at one time, and it can process the number of test pieces required for performance tests such as tensile, compression, bending, and interlaminar shear. It is better to use polytetrafluoroethylene cloth as the release sheet to make flat plates on the surface of the mold. No release agent is needed to prevent the release agent from migrating to the surface of the composite material, which makes the process of bonding aluminum sheets difficult. When a small amount of silicon ester is used to cover the release sheet on the mold surface, it can be flattened well to prevent the surface of the specimen from being smooth after curing.

During the winding process, the tension of each yarn is adjusted by a tension control device. Generally, the strength of the fiber is 5% -8%, and the tension should be kept stable. During the process, the glue tank can be heated to reduce the viscosity of the resin and improve the wettability of the resin to the fiber. The fibers should be evenly distributed on the surface of the mold to the required thickness, and the number of winding layers is calculated according to the following formula.

After winding, put the upper and lower pressure plates and thickness pads, pre-tighten the bolts, and leave them for about 2 hours to allow excess resin to flow out. Tighten the bolts evenly so that the upper and lower pressure plates of the mold are in contact with the pads. Use a sharp blade Cut the fiber at both ends of the core mold to release the winding tension and avoid warping and deformation of the board after curing. But cutting the fibers prematurely can make the fibers out of alignment. After the mold is placed in the oven, it is solidified according to the prescribed system. The temperature control accuracy is ± 3 ° C, and it is naturally cooled to room temperature. The mold is disassembled, and the prepared flat plate is added to various specifications.

Fiberglass Septic Tank

Fiberglass Septic Tank

2. Processing of specimens

After the unidirectional fiber composite material flat plate is prepared, the surface dust, impurities and other foreign matter are removed. According to the sample size and quantity required by the national standard, taking into account the width of the cutting edge, a special pencil is used to mark the fiber direction and 0 degrees, 90 degrees, For 45-degree tensile, compression, and bending of the specimen processing area, use a diamond wheel to cut the specimen on a special milling machine. For the shape and size of the specimen, refer to the corresponding standards.

3.Reinforcement sheet bonding

The reinforcing sheet is made of a glass fiber composite material plate having a thickness of 2-3mm orthogonally laminated or an aluminum plate having a thickness of 1-3mm. When the aluminum sheet is used to make a reinforcement sheet, the surface of the reinforcement sheet should be flat, and the surface oxide layer should be removed by sanding with an abrasive cloth. The reinforcement sheet should be heated to 65 ° C in an acid treatment solution and left for 15min, then rinsed with tap water, and then washed at 105 ° C. Bake for 2 hours to remove moisture. Do not touch the surface of the treated reinforcement sheet by hand. The weight ratio of the treatment liquid is sulfuric acid: distilled water: potassium dichromate = 10 : 30 : 1.

Before bonding the reinforcing sheet, sand the surface of the test piece with 100-grit sandpaper, wipe off the surface dust, use ethyl acetate to remove the mold release agent and the surface greasy, and wash the test piece with acetone and dry it cold. Due to the high tensile strength of the unidirectional composite material in the fiber direction, the reinforcing sheet easily slips during the tensile test. It is recommended to use epoxy 618: 200 # polyamide: diglycidyl ether: imidazole = 100: 80: 15: 2 . The test piece and the reinforcing sheet are coated with an adhesive and cured by applying contact pressure. The curing system is: the room temperature is increased to 60 degrees, the temperature is maintained for 2 hours and then raised to 120 degrees, and the temperature is lowered to room temperature after 8 hours of heat preservation. Tensile test specimens perpendicular to the fiber direction and 45-degree partial tensile test specimens have lower strength, and normal temperature adhesives can be used.

After the reinforcement sheet is cured, sand the surface of the test part with sandpaper to expose the fiber layer. Use acetone and ethyl acetate to remove the oil on the surface. Draw the measurement direction line. Paste the strain gauge with 502 adhesive. The properties of the tested materials are in the same direction, and the test piece is finished after the adhesive is cured.

The above is the repair of Fiberglass Septic Tank.