Solid wood composite flooring refers to the composite of three layers of different materials such as the surface plate, core plate and bottom plate, and is usually pre-painted. It is a relatively high-grade floor decoration material. This product can not only save high-quality wood, but also effectively use small-diameter materials to fully improve the comprehensive utilization rate of wood.
The solid wood composite floor studied by this top item is different from the conventional three-layer solid wood composite floor. It is a pre-painted floor provided by the client with a two-layer structure of the surface layer and the base material. Since there is no asymmetric structure of the bottom plate, the dimensional stability of the floor is poor, thus affecting the quality of the floor product. The purpose of this experiment is to investigate the use of conventional coatings and related auxiliary materials to seal the back and four sides of the floor to reduce the moisture absorption of the wood and cause thickness expansion, improve the dimensional stability of the floor, and examine the corresponding processing costs. .
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experiment material1
. 1 floor structure Surface layer: 1 . 2 mm rotary cut veneer, tree species of birch and eucalyptus, pre-painted. Substrate: Poplar finger jointed sheet, 18 mm thick . According to the form of the finger joint plate, it is divided into two types: a string cutting board and a diameter cutting board. Since the floor is directly applied to the substrate, the dimensional stability of the substrate is the key to the quality of the floor.1
. 2 paint formula composition Nitrocellulose coating: Q01 - 1 nitro varnish, milk white glue, emulsified paraffin, zinc chloride, talcum powder, Xinna water, melamine: Alkyd paint: C01 - 1 alkyd varnish, turpentine, talc, melamine, calcium carbonate (old powder).2
Test design According to the formulation of nitro and alkyd coatings prepared by preliminary test, orthogonal test was carried out to select two nitro paint formulations and one alkyd varnish formula, and then compare the treatment effect and treatment cost to determine the best ratio. .2
. 1 nitro coating formulaUse orthogonal table to investigate the modulation process, nitrocellulose lacquer, chloramine, emulsified paraffin, talcum powder and zinc chloride.
The thickness of the test piece and the cost of the test piece.
The preparation process is divided into two types according to the mixing order of each component: A and B. Each group of coatings is coated with 3 pieces of floor test pieces , and the total coating arrangement is 130g /m2, which is painted every 4 hours , each time 30 ~ 50 g / Square meters. The test piece was placed in a ventilated place for 24 h . After being completely dried, the test piece was placed in water of 20 to 25 degrees, soaked for 6 , 24 , 48 h , respectively , and then the water absorption thickness expansion rate of the test piece was measured for different water immersion time.2
. 2 alkyd paint formulaThe orthogonal table was selected to investigate the effect of turpentine oil, talc powder, melamine and old powder on the treatment effect and cost of the test piece.
Modulation process: first mix the talc powder and the old powder, add the turpentine and mix well, then add the alkyd varnish and mix well. Finally, add melamine and mix well. The paint was distributed to 3 pieces of painted floor test piece , and the total coating was arranged at 150 g / square meter, about 70 g / square meter per pass . The test piece in the ventilation Department 24 h, until all dry paint, placed were soaked 6, 24, 48 h 20 ~ 25 degrees in water and then measuring thickness swelling water absorption of the specimen at different times.3
. 1 . Effect modulated process (X1) of the TSFrom the test results, the modulation process
A is better than B because the powdery raw material is well dispersed. After mixing with a diluent, other liquid auxiliary materials are added, and the coating thickness is relatively uniform, and the effect on the wood sealing is remarkable.3
. 1 . 2 the amount of each component added to the shadow of the TS ( 1 ) Melamine ( X2 ) melamine is a white powdery crystal, which is hardly soluble in a certain range of water stone. Increasing the amount of melamine added can improve the dimensional stability of the test piece and reduce the swelling rate of water absorption. However, excessive addition affects the adhesion of the lacquer to the wood, and also has an effect on the flag hole effect of other auxiliaries. Tests show that the amount of people added is about 2 %3
results and analysis3
. 1 nitro coating formulation ratio test results and analysis The influence of various factors on the water absorption thickness expansion rate ( TS ) of the test piece is shown in Figure l(
2 ) When the amount of emulsifying paraffin ( X3 ) emulsified paraffin is low, the adhesion between the coating and the wood is affected, and the overall waterproof performance is lowered. With the increase of the amount of emulsified paraffin, the swelling ratio of the water absorption thickness of the test piece first increased and then decreased. The change of the water swell thickness expansion rate of the test piece diameter cutting plate for 48 h is the most obvious. ( 3 ) Vermiculite powder ( X4 ) natural talcum powder is light, soft and smooth, and has good hole filling effect. Adding a certain amount of talcum powder can not only reduce the thickness expansion rate, but also increase the film thickness and body quality, but excessive addition makes it easy to add paint.The appearance of the film is tarnished and rough.
( 4 ) Milky white glue ( x5 ) Milky white glue can improve the brittleness of the paint film, and can also reduce the cost to some extent. The amount of milk white glue added has the most significant effect on the water absorption thickness expansion rate TS of the diameter of the test piece for 48 h , and the suitable addition amount is about 30 %. ( 5 ) Zinc chloride ( X6 ) adds a certain amount of zinc chloride in the formula, which can improve the corrosion resistance of the floor to a certain extent, prolong the life of the wood floor, and play a certain flame retardant effect. Zinc chloride is a white granular deliquescent crystal or crystalline powder, so the amount added should not be too much, to 1 . About 5 % is appropriate. ( 6 ) Nitrocellulose paint ( x7 ) The addition of nitrocellulose lacquer in a certain range can effectively improve the dimensional stability of wood, and the most significant effect on the water swell thickness expansion rate of the diameter cutting board for 48 h . However, if the film is excessively added, the film is thickened, and cracks in the direction of the wood grain are generated, resulting in an increase in the rate of change of the water absorbing thickness expansion of the diameter cutting plate in the test piece, so the addition amount is preferably 30 %.3
. 2 Alkyd coating formulation ratio test results and analysis Effect of the amount of each component on the water absorption thickness expansion ratio ( TS ) of the test piece ( 1 ) The addition of turpentine ( X1 ) turpentine is most significant for the TS shadow of the test piece . As the amount of addition increases, the TS of the test piece increases significantly and the dimensional stability deteriorates. Although turpentine can effectively prevent the entry of moisture, the retention is poor, and it has a negative effect on the adhesion of the coating, resulting in a large amount of deformation in the later stage, so the dosage should not be too much, preferably 34 %. ( 2 ) The talc powder ( X2 ) talc powder has a significant influence on the test piece TS , and the added amount increases. The change rate between different time and curve increases, and the water resistance decreases. In addition, the appearance, body quality and dosage of the paint film are considered. Control is effective at 18 %.(
3 ) The overall waterproof performance of the melamine ( X3 ) test piece decreases with the increase of the amount of melamine added, but the amount of melamine added is too large, and the total deformation is also increased, so 4 % is preferred. ( 4 ) Calcium carbonate ( X4 ) Calcium carbonate is a natural lime powder, also known as old powder. It is usually added as a filler in coatings to increase the viscosity of the coating, increase the thickness and texture of the film, and make the film durable and wear-resistant. Adding a certain amount of calcium carbonate can play a waterproof role. With the increase of the amount of addition, the water absorption thickness expansion rate of the test piece is reduced within a certain range, but if the addition amount is too large, the dispersibility is deteriorated, and the coating is not easy to be uniform, so that The dimensional stability of the test piece is reduced. The appropriate amount to be added should be controlled at around 15 %.3
. 3 Determination of the best formula ratio Through the above analysis and the determination of the thickness expansion ratio of the floor chord and the diameter cutting board, combined with the top and the cost top indicators, the optimum formula is determined as follows (mass percentage): (1) nitro coating: 30% nitrocellulose lacquer, white gum 30%, 6% talc, 2% paraffin wax emulsion, a zinc chloride. 5 %, believe that water 28 . 5 %, melamine 2 %. ( 2 ) Alkyd coatings: 25 % alkyd varnish , 34 % turpentine , 22 % talc , tripolyamide, calcium carbonate (old powder) 15 %.3
. 3 cost comparison From the perspective of comprehensive benefits, the nitro formula needs to be painted 3 times, the production cycle is long, and the cost is higher than the alkyd formula. Therefore, in the production, the alkyd formula should be selected for the post-treatment of the solid composite floor.4
in conclusion ( 1 ) The optimum ratio of alkyd coatings determined in this test is: alkyd varnish 25 %, turpentine 34 %, talc 22 %, melamine 4 %, calcium carbonate (old powder) 15 %.2
The post-treatment of the solid wood composite floor with the alkyd varnish-based paint can effectively reduce the water absorption thickness expansion rate and improve the dimensional stability of the product, and the cost is lower than other similar treatment methods.3
Paint coating is a very important part in the processing of flooring products. As long as the coating composition and ratio are selected reasonably, it can prevent the diffusion rate of water in the wood to a certain extent, and at the same time play a certain balance layer. In addition, the coating finishing treatment not only improves the dimensional stability of the product, but also makes the appearance of the floor beautify and durable.Sports Artificial Grass,Synthetic Grass,Artificial Golf Course,Artificial Grass
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