Process flow of LVT floor
Base material, medium material -- hot pressing (pressing), health -- roller coating, tempering, health -- punching, health -- trimming or grooving -- packaging
1. Base material (medium material) workshop
1.1 production process
Put the polyvinyl chloride resin powder, plasticizer, stabilizer and carbon black into the mixer according to the formula proportion, and the machine will automatically add plasticizer. 10 minutes later, add the stone powder, stir for about 30 minutes, the mix evenly into the conveyor belt, into the mixer heating mixer. In the mixer, the machine turns over the material for a total of 4 minutes, and then the raw material powder enters the roller. After being pressed by the roller, the powder gradually takes shape at a temperature of about 170℃. Finally, it is cooled and refined, and the raw material is cut into blocks of 1*1m or 1*1.3m.
1.1.1 function of each raw material
The bottom material is often more ductile not easy to break, by PVC, calcium powder, plasticizer and other materials, the middle material is relatively easy to break, so the bottom material and the middle material together can play a role in stretching, so that the plate is not easy to become warped.
PVC resin powder: PVC is a kind of non-toxic, odorless white powder. It has high chemical stability and good plasticity. PVC is the most widely used and important polymer in the world, but pure PVC is actually the most unstable polymer, so only after adding the appropriate stabilizer and other additives, the advantages of PVC can be reflected.
Carbon black: the pigment with the strongest colouring and hiding power, the most stable pigment, resistant to heat, chemicals and light
Stone powder: insoluble in water soluble in acid, function: to increase the opacity, improve the flexibility of paper
DOTP(plasticizer) : it is a colorless liquid with low viscosity. Since PVC itself is a hard material, the plasticizer can make the finished plastic product soft, easy to bend, fold, good elasticity and easy to shape.
(there is another plasticizer np-1 in the mixing area, whose performance is weaker than DOTP, and it is selected for use according to specific customer needs. DIBT standard requires all floor materials to be DOTP)
Stabilizer: it can slow down the reaction, maintain the chemical balance, reduce the surface tension, prevent light, thermal decomposition or oxidation reaction, so as to promote the product quality stability.
1.2 relevant terms
Stir zone (agitationarea), mixer (agitater), plasticizer DOTP plasticizer (), polyvinyl chloride (PVC) tree powder (polyvinyl Chlorideand resin), hardness (hardness), stone (limepowder), carbon black (black carbon), thickness (thickness) and stabilizer (stabilizer), mixing time (mixingtime), Roller temperature, firstroller temperature, second roller temperature, out slice temperature, proportion
1.3 relevant parameters
First roll temperature: 160---170 ° c; second roll temperature: 150---160 ° c; tablet temperature: 160---170 ° c;
1.3.1 the size of medium base plate is generally 1300mm*1000mm* thickness and 1000mm*1000mm* thickness to meet the needs of customers and the size of the press.
In the thickness of the material specification 0.6, 0.75, 0.8, 0.9, 1.0, 1.15, 1.7 (mm), the thickness of the base specification is 0.6 0.8 0.9 1.0 (mm).
1.3.2 the composition of medium material board and base material board is not fixed, especially medium material board, which can be divided into: A: new material; B: leftover material + stone powder; C: return material + scrap material + stone powder, etc. After the two commonly known as back to the furnace (Recycled Material), and new Material (Original Material) relative, the cost is lower, the Material layer by different components of many pieces of Material plate press paste. But in general,
A: the base material is of high quality and new materials are used.
B: glue-free floor materials are of higher quality than those with glue or lock, especially softness and toughness.
Flexibility and toughness are related to the composition of the material (new material or recycled material) and the formulation.
C. The leftover materials after the floor punching and cutting made of new materials are also counted as new materials; Return material is generally bought from other factories waste material, the two in metal content and other aspects of a large gap.
According to customer's requirements, medium and base materials can be made into green, white and other different colors by adding pigment, so as to distinguish the black or gray of the masses. Medium and base material is not distinguished by thickness, unrelated to thickness, and specific gravity (density), so can not be said to be thicker than base material.
1.4 production line and capacity
2 production lines, 2 shifts a day, each shift 12 hours, each shift capacity 3500-5500 square meters.
1.5 matters needing attention
1.5.1 Quality Control and Quality Insurance
Possible quality problems and solutions in the operation and production of the material workshop:
Quality problem cause quality control
A: the Middle Height temperature of the base material is not enough or the wear temperature of the chip roller should be monitored from time to time. The chip roller should be updated
B: the temperature of the base material Bubble is not controlled properly
C: the White Spot of base material is not evenly mixed, the moisture of stone powder is too high for incoming material monitoring, and the mixing time is prolonged
From the field quality monitoring, the bubble and the base material white point mainly depends on whether the proportion is large, the proportion of return material bubble and white point is large, the new material is small.
1.5.2 process inspection standards:
Appearance of middle base material: new material, no impurities, obvious bubbles, white spots and color difference, rubber particles less than 2mm and less than 3 per square meter
Thickness: +-0.05mm, Thickness and average value of the sheet shall not exceed 0.05mm
Proportion: 1.95+-0.05g/cm3 base: 1.65+-0.05g/cm3
Hardness: medium (commercial)60+-2 ° c (for locking)68+-2 ° c
Base material :(commercial)54+-2 degree (lock)64+-2 degree
1. Hot press workshop
2.1 production process
In sheet metal, in turn, spread on the canvas, embossing board, soft membrane (matt membrane, high temperature paper), base material, frosted sheet (wear-resisting layer), color film, and soft membrane (matt membrane, high temperature paper), with another piece of steel plate after pressed into hot press, continuously heating pressure, about 40 minutes later, tear off after the soft membrane, floor pressure forming. In this process, the upper and lower two sides of a embossed plate press grain, namely a embossed plate pressure two floors; Depending on customer requirements, it is sometimes necessary to add glass fiber between medium and medium.
2.1.1 auxiliary materials
The role of the canvas is in the hot pressing process, to prevent the press of high temperature and high pressure ironing surface; Glass fiber mesh is the most not affected by the environment to produce shrinkage and expansion of the material, mainly used to increase the toughness of the floor, and cooling and high temperature on the shrinkage and warping have a certain control role. Soft film, sub-light film, high temperature paper: control brightness and tension. Fiberglass must be added to loose lay products and the rest depends on customer demand. Frosted sheet, color film, black skin are the main components of PVC.
2.1.2 design and color of plastic floor and surface layer
Colour code and surface: distinguish the type of floor by surface, the surface currently in production includes: antique wood texture(BP), hand scrape(hand scrape), crystal(crystal face), EIR(synchronized flower);
3. Roller coating and tempering workshop
3.1 production process
The whole floor will be pressed into the conveyor belt, by the roller evenly coated with a layer of UV coating, after receiving ultraviolet radiation and into the oven for baking, coating fully solidified, the floor will be sent into cold water cooling. Finally, dry the water on the surface with a cold air blower. Finally, put it under normal temperature for health preservation. The specific time is as follows:
Transparent material < =0.3mm health preservation time: 24H
Transparent material > =0.3mm health preservation time: 48H
In this process, uv paint will roll twice, uv irradiation is also two, the overall process can be summarized as: hot roll, hot roll, back cold blowing. The purpose of UV paint is to increase the gloss to meet the customer's requirements (floor brightness and UV paint dosage is not directly related, mainly by UV paint brightness to control), the purpose of tempering is through the heating and cooling on the assembly line of PVC floor shrinkage and warping process.
4. Punching and cutting workshop
4.1 production process
Place the floor in a warm pool or heat it with a machine to make it easier to cut. Wash off the water on the surface with sponge and send it to the punching machine. Generally cut 5-6 pieces (936X150mm, all 6 pieces); 1220X180mm, all 5 pieces), cut after the small pieces of floor code on the tray.
4.1.1 product size determination
W steel plate size: 1000 x 1000mm; 1300 x 1000 mm
W available size: 942 x 942; 1227 x 942 mm
Size of w after punching and cutting: 942 x 157mm; 1227 x 157 mm
Size of w after grooving: 936 x 150mm; 1220 x 150 mm
4.1.2 number of large plates
The number of sheets is calculated as :(the number of packets * the number of pieces per packet)/ the number of small sheets that can be cut by a large sheet
1220 * 180 OR 1227 * 187 1 punch 5
1210 *190 OR 1218 *197 1 punch 4
1220*150 OR 1227*157 1 punch 6
1220*228 OR 1227*235 1 punch 4
936*150 OR 942*157 1 punch 6
600*300 OR 608*308 1 flush 6
470*470 1 impact 4 can not be used as a lock for the time being
914.4*101.6 1 punch 9 temporarily can not do the lock, too narrow
5. Edge cutting workshop
After health maintenance according to customer requirements for edge cutting, edge cutting 2 production lines, the capacity of 2W pieces
6. Tank car
6.1 production process
After the health according to customer requirements for grooving, grooving is by the adjustment tool according to the size of the floor according to the specifications of debugging tools, adjusted, will be a piece of floor on the conveyor belt, first open long side, after the opening of the short side, the back of the floor will be sprayed on the production date.
6.2 relevant parameters
Size data: below 230mm :0.15mm; 230 mm - 610 mm, 0.3 mm; 610 mm - 1380 mm, 0.5 mm
5.3.3 straightness: less than 0.15mm
5.3.4 straight Angle: less than 0.10mm
5.3.5 gap degree: less than 0.15mm
5.3.6 high and low: less than 0.10mm
6.3 production lines and capacity
One production line with capacity of 2W pieces
7. Packaging workshop
7.1 production process
Floor into the box is a form of cooperation between two people, one person inspection, do into the box before the final cleaning work, especially to remove obvious scrapes, scrapes, impurities, smudges, rounded corners, bubbles, color difference, discoloration, white edge, buckle damage, lamination, folding material, bevel, residual corner and other defective products, is equal to the last checkpoint of quality. One person sealed the box. Check the accuracy of the label and shipping mark.
7.2 matters needing attention
7.2.1 after putting into the box, put it on the wooden pallet. Please note that the moisture content of the wooden pallet is less than 20%. Iron nails, rot and moth are not allowed. PVC tray type: plywood (main), solid wood, packaging box according to the printing process is divided into: color box and (kraft) black and white box.
7.2.2 finished product appearance inspection items
There is no impurity, indentation, gloss, color, surface non-destructive Angle, stain (oil), crystal point, pit, crack, bubble, pinhole, buckle type.
Inspection method: under natural light or 40W fluorescent lamp, carry out visual inspection about 600mm away from the inspection point.
Physical performance inspection of finished products:
Peeling strength (tested with tension meter), heating size change rate, heating warping, abrasion resistance.
7.2.3 size data: below 230mm :0.15mm; 230 mm - 610 mm, 0.3 mm; 610 mm - 1380 mm, 0.5 mm
7.3 6 production line packaging sets