The study of the performance test method of reinforcing the performance with osmosis primer in the interior and exterior walls of the building

At present, the performance testing of primers used in the interior and exterior walls of the building is mainly carried out in accordance with the JG/T210-2007 "the method prescribed by the primer for the interior and exterior walls of the building", during the period of standard formulation, the number of osmosis primer products is limited, the level of product research and development is not yet mature, so the standard does not include the testing methods and indicators of such products. In recent years, with the improvement of coating technology level, the proportion of osmosis primer product use increased, but there is no suitable unified laboratory test method for product reinforcement performance and quality testing and determination, this paper combined with the role of osmosis primer, the test method of its reinforcement performance was explored and studied.
1 test part1.1 Test materials
titanium dioxide (A, B), dispersants (A, B, C), thickeners (A), desolation agents (A, B, C), anti-sinking agents (A), transparent tape (powerful NO.30029, 3M600), glass plate (400mm
×150mm ×3mm), cement mortar blocks (in accordance with JG/T157-2009 6.3.2), powdered polyethylene alcohol (PVA-1788), CaCO3 (400 mesh, particle size D50 is 8 to 12 m). All of the above materials are commercially available.
1.2 sample samples
31 osmosis primer samples provided by different primer manufacturers. Among them, the outer wall type penetration primer 26, the inner wall penetration primer 3, the internal wall universal penetration primer 2.
1.3 test equipment and appliances
wet film preparationer (60 m×, 150 m): Guangzhou Standard Gerda Laboratory Instrument Supplies Co., Ltd.;
1.4 test method
1.4.1 tape dislocation area method
(1) titanium white slurry preparation: in containers with high-speed agitators in order and proportion of table 1 to add the various parts, high-speed stirring (approximately 1000r/ min) 40min, filtered with 325 mesh filter, set aside filter,
(2) with 60 m wet film preparationer in the wipe clean glass plate surface coating the above titanium slurry, put in 100 degrees C blowing drying box 3 0min, remove and cool to room temperature;
(3) scrape the film surface of the dried titanium slurry coating for test using a 150 m wet film preparer, and
(4) prepare the primer coating in (23±2) Under the conditions of C, relative humidity (50±5), place 72h;
(5) paste transparent tape on the surface of the primer prepared above, press flat and tear apart,
(6) check the dislocation of the coating, Evaluate the area where the tape sticks to the titanium slurry with primer.
Table 1: Titanium White Slurry Formula I.
1.4.2 Tape Disloyation Quality Method
(1) Preparation of Titanium White/CaCO3 Slurry by Table 2: Water 49g and Dispersion 1g at Low Speed (100 to 150r/min) Stirring Conditions; .08g, continue to stir until all particles are completely dissolved, the solution viscosity increased significantly, and then slowly add titanium dioxide / CaCO3100g and desolation agent 0.2g, all add and clean the stirring leaves adhered to the titanium white powder / CaCO3 powder, adjust the speed to high speed (about 1000r/min), stirring 40min after 12h.
(2) With a 60 m wet film preparation along the length direction, in the middle area of the wiped clean glass plate evenly coated with the above titanium/CaCO3 slurry, put in a 100 degrees C blowing drying box placed 8h, remove cooling to room temperature.
(3) along the width direction of the glass plate, in the above titanium/CaCO3 slurry film paste the specified transparent pressure-sensitive tape (powerful NO.30029 type), 2 tape should be just the distance between the 150 m wet film preparation on both sides of the border covered, along the track made of 2 tape with 150 m wet film preparationer scraping to be tested.
(4) the coating prepared for the primer is maintained at (23±2) degrees C and relative humidity (50±5) % conditions of 7d.
(5) on the surface of the above-made coated primer, paste the specified transparent pressure-sensitive tape (3M600 type) along the length direction of the glass plate, use the standard rolling roller to roll back and forth 3 times, and then pull up the tape as slowly as possible at an angle of 45 degrees.
(6) using a tablet press in the middle position of the tape pulled above to cut 50mm×50mm squares, pay attention to the cutting process to avoid film shedding, the use of balance weighing, weighing results less the quality of the tape. 3 models are prepared in parallel for each sample, and the weighing mass is measured by the arithmetic average of the results 3 times.
Table 2: Titanium White Powder/CaCO3 Slurry Formula
1.4.3 Reinforcement Strength Test
1.4.3.1 Test Block Preparation
Conforms to JG/T157-2009 .3.2 The cement mortar block specified, the test block molding surface is flat, no pits, holes, missing angles, missing edges, before the test in (23±2) degrees C, relative humidity (50±5) % environment maintenance 48h. Smooth the molding surface of the mortar test block with 0-dry scrub paper to remove the surface dust.
1.4.3.2 Sample preparation
(1) configuration 0.5% PVA aqueous solution
slowly adding powdered polyethylene alcohol to the water at high speed stirring, after the polyethylene alcohol is added, continue to stir at high speed into the solution such as no group, block When the material is present, after 80 mesh filter, the filter liquid is placed in the environment of (23±2), (50±5) RH, the storage period is not more than 30d, during which such phenomena as reunion, precipitation, etc., the use of low-speed mechanical stirring after use.
(2) prepare 0.5% PVA-CaCO3 substrate raw material
in the above 0.5% PVA aqueous solution, the stirring side is added 400 eyes CaCO3 (particle size D50 is 8 to 12 m), m (0.5% PVA aqueous solution): m (CaCO3) is 1:3.
(3) prepare 0.5% PVA-CaCO3 substrate blank sample
according to GB/T9779-2015 6.18.2.1 provisions and methods on the 1.4.3.1 specified cement mortar block scraping Apply 1.4.3.2 prepared 0.5% PVA-CaCO3 substrate raw material, wipe the surface of the mortar block with a damp cloth before scraping, to scrape 0.5% PVA-CaCO3 substrate raw material, the surface does not produce bubbles, empty drum is appropriate. Scrape 2 sets of samples, thickness of 0.5mm, 1mm. A total of 12 samples were prepared for each group and maintained at (23±2) degrees C, relative humidity (50±5) % environment 72h;
(4) Preparation of reinforced performance test samples
on the end of the maintenance period of the sample prepared at 1.4.3.2), the primer sample to be tested is painted on 6 0.5% PVA-CaCO3 test blocks (note not to paint on cement mortar other than 0.5% PVA-CaCO3), with a total coating of 0.3 to 0.4g per sample.
measurement of 1.4.3.3 bonding strength
1.4.3.2 blank samples and reinforcement properties were tested according to gb/T9779-2015 6.18 Test the adhesive strength of the sample, before the maintenance period expires 24h, put the test piece in a horizontal state, using a temperature-cured high viscosity adhesive evenly bonded to the steel fixture, not to use the adhesive overflow, flowing to the surface of the mortar block test piece. The bonding strength of the blank sample should not be greater than 0.1MPa.
the results by removing a maximum and a minimum value and taking the arithmetic average of the remaining four data.
2 results and discussions2.1 tape dissoquent area method
In the building inside and outside the wall with primer construction site, often use tape compaction after tearing, observe tape adhesion coating area, or use hand friction wall after observing the powder situation and other methods to easily judge the penetration primer on the grass-roots reinforcement effect. On the basis of this idea, combined with a permeable primer manufacturer's own method, the experimental method of 1.4.1 is designed, and the reinforcement performance of the primer is evaluated by means of the area of the adhesive coating after tearing off the quantitative tape. Figure 1 shows the test results of 4 different permeable primer products.
Figure 1: Different primer dislocation conditions
as can be seen from Figure 1, the area under which the sample is glued is large and thick, the area under which the sample is glued is small and thin, the sample is uneven everywhere, and the coating of the sample is glued to pieces. It can be seen that different osmotic primers in accordance with the tape dislocation area method for testing, there are indeed different primer dislocation conditions, but with the original test scenario there are still some differences, there are the following problems:
(1) tape dislodged after the coating thickness is not the same, by judging the coating area after the tape is dislodged to evaluate the reinforcement performance of the osmotic primer, it is difficult to give quantitative test results
; Powder is a factory-specific model products, affecting the general applicability of the test method,
(3) different models of tape bonding strength, resulting in different test results,
(4) method on the tape press flattening method has no quantitative provisions, different artificial operation will inevitably result in differences in results,
(5) titanium white powder and substrate daily use of the substrate material differences, can not really reflect the actual use of the situation.
, this idea is basically suitable as a qualitative method to check the performance of osmosis primer reinforcement, but it still needs to be improved in details such as method generality and quantity. On this basis, we consider using a 1.4.2 test method to test the quality of the adhesive coating after the tape is dislodged to determine the reinforcement performance of the osmosis primer.
2.2 Tape Dissoctication Quality Method
For the problems of tape dissocation area method, a large number of formulation debugging and method adjustment, including:
(1) to find suitable generic chemical reagents (B/C) alternative dissocation area method in the endetter model dispersant;
(2) through the test specified the type of tape (powerful NO.30029 type, 3M600 type) and the weight mass (2000g, width) during the flattening of tape process weight (2000g, width 50mm) and the number of recourses of weight rolling (3 times);
(3) tested to replace titanium carbonate with calcium carbonate (formula V./VI.), taking into account calcium carbonate strength and Calcium carbonate slurry film preparation 2% PVA and calcium carbonate mixed solution instead of titanium white (formula VII.);
(4) using a tablet press after the end of the test cutting tape, using a legal weight primer called quality reinforcement performance.
Table 3 is the preparation result of 6 slurry obtained according to Table 2 formula and the phenomenon after plate making, where formula V./VI./VII. is difficult to form a film on the glass plate surface and cannot be followed by follow-up test in accordance with this method.
table 3: 6 formula slurry phenomena
Figure 2 respectively, formula II./III./IV. continued to be tested in accordance with the 1.4.2 test method, the resulting tape adhesion coating effect, visually judged that the same primer product of the same formula 3 test results are significantly different. The dissociated quality obtained after the quality calculation of the sample cut is seen in Table 4.
Figure 2: Tape Dislocation
Table 4: Formula II./III./IV. Tape Dispensing Adhesive Coating Quality
1 tape dislocation area method of some problems, but the method in cutting tape and other aspects of operational difficulties, the press cutting tape easy to cause tape adhesion coating shedding, powder drop;
2.3 Bonding strength test method
osmosis primer reinforcement performance test method at home and abroad standards and literature have no reference content, at the same time, the above-mentioned tape designed in this paper dissoquent test area and quality test method, there are still some technical difficulties, in this foundation Above, considering that the mechanism of osmosis primer is through its good penetration performance, seeping into the grass-roots internal reinforcement base and blocking the base internal saline into the coating layer, so the conversion idea, using a more intuitive test of bonding strength test method to evaluate the reinforcement performance of the osmotic primer.
Because the interior and exterior walls of the building are applied directly to the base of the building wall with primers, and putty base is the majority, in order to make the substrate used in the test method similar to the actual substrate, the experimental design uses calcium carbonate as the substrate raw material, but because calcium carbonate self-strength is not high, it is difficult to become Type test block, so the use of JG/T210-2007 anti-pan-alkaline test used in the PVA aqueous solution as an adhesive, after testing, the configuration of 0.5% PVA-CaCO3 substrate raw material strength is appropriate. According to 1.4.3.2 scraping 0.5% PVA-CaCO3 substrate when the test scraping 0.5mm and scraping 1mm2 cases, through the ratio found that the thickness of the substrate 1mm, although different primer sample penetration depth is different, but the vast majority of It is more difficult to penetrate through the entire substrate, so the detection of bond strength fracture position will be the weakest link in the whole system, that is, reflects the cohesion strength of 0.5% PVA-CaCO3 substrate, but not a good reflection of the difference between different osmosis primers, so the thickness of the substrate is 0.5mm is more appropriate. Table 5 is based on the test method of 1.4.3 for 31 osmosis primer samples.
Table 5: Test results of osmosis primer reinforcement performance
as can be seen from Table 5, of which 21 samples with adhesive strength ≥0.20MPa, accounting for ≥ 6 ≥7.7%; Some primer products have small bonding strength, which is mainly due to 2 kinds: First, due to the poor permeability of such products, its penetration depth does not reach the cement mortar block base, when the detection of bonding strength fracture occurs on 0.5% PVA-CaCO3 substrate, Therefore, the results of the bond strength test are similar to the results of the blank sample, and secondly, although some primer products can penetrate into the 0.5% PVA-CaCO3 substrate and reach the cement mortar block base, the primer itself has no obvious reinforcement effect on the substrate. It can be seen that only the permeable and reinforcing osmosis primer meets both permeability and reinforcement, measured according to this method