One, PVC foam board introduction
PVC foam board is also known as snow board or Andy board, according to the production process, appearance and performance can be divided into PVC foam board and free foam board.
PVC skin foam board is produced by Celuca process, with a layer of hard skin on the surface, smooth and smooth, high hardness, good mechanical properties, and high precision products, small thickness error, strict requirements on mold, formula, process and raw materials.
The surface of PVC free foaming board is loose, there is no crust, and the surface is fine and convex, which is conducive to printing, spraying and veneering. It can be produced by ordinary foaming mold, and the process is relatively easy to control.
Two, the characteristics of PVC foam board
Practice has proved that PVC foam board has good thermal insulation, heat preservation, sound insulation, light bearing and other properties, better than other light solid plastic expanded perlite, ceramsite, asbestos products and other insulation materials, has the characteristics of simple operation, high degree of mechanization, time saving, labor saving. PVC foam board can be transported by mechanical vertical pipeline, which shortens the working time and improves the efficiency by 6~10 times compared with other ways.
PVC foam board made insulation layer, used for roof insulation and external wall insulation, has incomparable thermal insulation performance and adhesion performance for the structural layer, and convenient construction, environmental protection, time saving, efficiency and many other advantages, can be used to replace polystyrene (benzene board) and other heat insulation materials. PVC foam board is also used in the southern region to make PVC foam board bricks, in order to achieve the purpose of roof insulation and external wall insulation. It has the following features:
1) Economy: low comprehensive cost.
2) Thermal insulation: the thermal conductivity is 0.06-0.070W/ (M.K), and the thermal resistance is about 10-20 times that of ordinary concrete.
3) lightweight: dry volume density of 200-300kg /M3, equivalent to about 1/5 ~ 1/8 of ordinary cement concrete, can reduce the overall load of the building.
4) Compressive strength: compressive strength is 0.6-25.0MPA.
5) Integrity: can be site pouring construction, closely combined with the main project, no need to leave boundary seam and ventilation pipe.
6) low elastic shock absorption: the porosity of PVC foam board makes it have low elastic modulus, so that it has good absorption and dispersion effect on impact load.
7) Simple construction: only the use of PVC foaming board machine can realize automatic operation, can realize the vertical height of 200 meters of long-distance transportation, the workload is 150-300m3 / working day.
8) Sound insulation: PVC foam board insulation board contains a large number of independent bubbles, and uniform distribution, sound absorption capacity of 0.09-0.19%, is 5 times of ordinary concrete, with effective sound insulation function.
9) Water resistance: cast-in-place PVC foam board has small water absorption, relatively independent closed bubbles and good integrity, so that it has a certain waterproof performance.
10) After adding the color master material, the product can be made into a variety of colors, after the weatherproof formula is made, its color can be long unchanged, not easy to aging.
11) It can be drilled, sawed, nailed, planed and glued like wood, and can be constructed using general wood processing tools. The finished product can be used for secondary hot forming and folding processing, and can be bonded directly with other PVC materials.
Third, product deficiencies
PVC FOAMED BOARD HAS NUMEROUS ADVANTAGES, BE REGARDED AS THE MOST POTENTIAL IN FOREIGN “TRADITIONAL WOOD MATERIAL INSTEAD OF GOODS”, according TO the different applicable places, THE performance OF THE product IS also somewhat different. For example, “home decoration PVC board” pays more attention to safety and environmental protection performance, comfort performance and special environmental performance, while “commercial PVC board” pays more attention to durability performance, economic performance, cleaning and maintenance performance. People usually understand the three misunderstandings of PVC foam board:
1, flame retardant is not “can’t burn”;
Some people want to take a lighter to fire PVC foam board, to see if they can burn up, burn up is not fire, burn up is flame retardant. This is A common misunderstanding, the national requirements for PVC foam board fire rating BF1-T0 level of the standard, according to the national standard for non-combustible materials as fire A level, such as stone, brick, etc. Bf1-t0 grade flame retardant standard technology contains a diameter of 10㎜ cotton ball, dipped in alcohol, placed on the PVC floor natural combustion, cotton ball burned out, measured the diameter of the burned PVC floor trace, such as less than 50㎜, is BF1-T0 grade flame retardant standard.
2, not environmental protection is not by “nose smell”;
PVC material itself does not contain formaldehyde, PVC floor is not allowed to use formaldehyde in the production process, some advanced PVC foam board will use new calcium carbonate raw materials, just made of products will have a light taste, will not cause harm to people’s body, will not make people feel uncomfortable. It will disperse after a period of ventilation.
3, “wear-resistant” is not “with sharp tools won’t scratch bad”;
When some people ask about the service life and wear resistance of PVC foam board, they take out a knife or key and other sharp tools and scratch the surface of PVC floor. If there is a scratch, it is not wear-resistant. Actually THE COUNTRY IS OPPOSITE PVC FLOOR ABRASION RESISTANCE TEST IS NOT SIMPLY DELIMIT WITH SHARP OBJECT IN THE SURFACE, HOWEVER BY NATIONAL DETECTION ORGANIZATION IS MEASURED SPECIALLY.
Four, the performance of PVC foam board
1. Mechanical properties
PVC foam board has high hardness and mechanical properties. It increases with the increase of molecular weight, but decreases with the increase of temperature. Rigid PVC has good mechanical properties, and its elastic modulus can reach 1500-3000mpa. The elasticity of soft PVC is 1.5-15 MPa. But the elongation at break is as high as 200%-450%. PVC friction is general, static friction coefficient of 0.4-0.5, dynamic friction coefficient of 0.23.
2, electrical performance
PVC foam board is a kind of polymer with good electrical properties, but due to its larger polarity, electrical insulation is not as good as PP and PE. Large dielectric constant, tangent of dielectric loss Angle and volume resistivity, poor corona resistance, generally suitable for low and medium voltage insulation materials.
3. Thermal performance
PVC foam board heat stability is very poor, 140℃ began to decompose, melting temperature of 160℃. PVC linear expansion coefficient is small, with flammability, oxidation index as high as 45.
Five, foaming board production requirements
1. Production process
Hard PVC crusty foam board production process is as follows: PVC resin + additives → high speed mixing → low speed cold mixing → cone twin screw extrusion → mold formation (crusty foam) → cooling and shaping → multi-roller traction → cutting products → collection and inspection. The specifications of the hard PVC crusted foam board products are 1 220 mm×2 440 mm, and the thickness of the products is 8 ~ 32 mm.
1.2 Production line layout
2. Raw material requirements
Resin: PVC generally choose 8 type resin, processing gelation speed is fast, processing temperature is relatively low, product quality is stable, density is easy to control. In recent years, many manufacturers have changed to type 5 resin.
Stabilizer: the selection of stabilizer, considering environmental protection and good effect of the first choice of rare earth stabilizer, but because of the relatively high price, has not been promoted, the future with the increasing requirements of environmental protection, rare earth stabilizer market will welcome bright prospects. Calcium and zinc stabilizer has zinc burning problem and the stabilization effect is slightly poor and the dosage is less. At present, the most used or lead salt stabilizer, foaming board due to the wide cross section of the mold, long channel and yellow foam decomposition heat production, the stabilizer requires high lead content, good stability effect, otherwise the product is prone to various problems.
Blowing agent: the selection of blowing agent, blowing agent AC in the decomposition process to release a lot of heat, easy to lead to yellow section in the middle, which requires a certain amount of white blowing agent, decomposition to absorb excess heat energy, the number of foaming agent to be large, in order to achieve uniform foaming without large bubble hole.
Regulator: foaming regulator, through years of research and development and improvement, foaming regulator ACR process technology is more and more mature, performance quality is more and more stable, foaming board according to thickness, thin plate should choose fast plasticizing, thick plate should choose plasticizing slow solution strength of the foaming regulator.
Lubricants: The selection of lubricants follows the principle of both early, middle and late lubrication, so that the materials are protected by lubricants in all stages, and adhere to long-term stable production without precipitating and scaling.
Foaming agent: A small amount of foaming agent zinc oxide can be added in the production to improve the foaming quality and foam structure, and a small amount of aluminum silicate can be added to reduce the precipitation.
Pigment: In order to achieve a more beautiful effect, titanium dioxide and fluorescent whitening agent can be added, in order to improve weather resistance can be added antioxidants and ultraviolet absorbent.
Filling agent: light calcium carbonate can be selected, without the use of active calcium, the selection of high mesh number
Post time: Aug-16-2022