First, woodworking production
1, the production of the bottom plate.
On the ground to play a baseline, according to the baseline to form the bottom plate frame with planks on the ground, adjust the level, with FRP will be the frame and the ground fixed, and then on the wood frame on the woodworking board, adjust to the level.
2, determine the top view.
Draw the standing spacing on the floor and the semi-wide edges of each standing board by the Type value table, and then connect the endpoints of the semi-wide edges of each standing board so that the top view can be determined.
3, the production of wood model.
According to the type of value table to draw a standing board line diagram on the woodworking board, cutting to make it molded. Fix the standing board and the bottom plate with wood strips. Fix standing board with wooden strips, and close the entire model frame with woodworking board.
Second, moisture-proof layer, apply putty, spray easy polishing rubber clothing.
1, paste moisture-proof layer.
Paste 2 layers of 400g fiberglass cloth on the wood mold surface, to reinforce the strength of the wood mold, and to prevent mold surface deformation and moisture-proof. After the FRP curing, then carry on the surface external reason (such as the angle, the burr, the overlap and so on).
2, Insert the poly-putty on the base mold.
Add appropriate amount of curing agent to the putty. Generally, the amount of curing agent is 2% per barrel of poly-putty at 20 ° C, then stir evenly and apply on the base mold. According to the shape of the model, make base mold smooth with a hose or a ruler. Repeat the above sequence until the base mold reaches the desired shape.
3, spray easy to sanding gel coat.
After the polishing is completed, clean the dust and debris on the surface of the base mold. The easy-to-polish gel coat is evenly sprayed on the surface of the base mold.
- When spraying the gel coat, the diluent: gel coat = 1:1.5, the amount of curing agent is 1% – 2% of the gel coat.
- The thickness of the gel coat is not less than 1 mm, the gel coat is divided into 2 layers, and the spraying process is completed several times until the thickness of the gel coat reaches a desired level.
- Easy to sanding gel coat curing time is generally controlled at 45 minutes.
4, polish the gel coat.
After the gel coat is cured for 12 hours, choose corresponding iron sandpaper, and use flat sanding machine to polish the surface of the gel coat to make it basically smooth, and then polished with waterproof abrasive paper until it is smooth and bright.
Third, wet sanding, polishing, waxing, upper mold gel coat
- Wet sanding: Wet sanding with waterproof abrasive paper 400#, 600#, 1000#, 1200#. In order to facilitate the operation, generally make a rectangular foam block wrapped with sandpaper, take some water (usually put a proper amount of washing powder in the water to effectively lubricate the utilization of the sandpaper), and sanding in a uniform direction according to the shape of the model until the surface of the model smooth and there is no light (to prevent sand leakage). Pay attention to the model when it is wet sanding. After the wet sanding is finished, clean the model, dry it with a clean towel, and polish it after drying.
- Polishing: evenly coated with the #1 abrasive on the surface of the tire mold, polishing with a wool throwing disc. After the #1 abrasive is finished, use #3 abrasive to polish and clean.
- Mold release wax treatment: usually use solid wax and liquid wax. a) Solid wax is generally wiped with a sponge in a swirling manner. In order to prevent remaining the wax residue on the surface to increase the thickness, we usually wait for about half an hour after the first layer of wax is finished. After the wax completely infiltrate the inner layer, wipe off the excess wax with a clean thread and then go through the second time. The solid wax is rubbed more frequently during use, generally about 15~16 times. b) Liquid wax is generally wiped with a thread by means of a whirl method. It takes short time to forms a wax mold but price is expensive. It can be wiped continuously. Liquid wax usually takes only 3 to 4 times.
- Polishing: generally use #1 wax, #3 wax for two polishing. Wipe the mold clean, make the clean polished cotton ring installed, and test the polishing machine. First apply the #1 wax evenly on the model and polish it on the model with a polisher. Then apply the #3 wax and polish in a spiral manner until the surface of the model is very smooth and beautiful. Usually after polishing for a while, clean the polishing cotton or replace it with a new one.
- Brush mold gel coat: mold gel coat operation process is a crucial step in mold manufacturing, high-quality mold surface requires very precise mold gel coat operation process. Mold gel coats are generally black. Each batch of gel coats needs to be tested firstly, and the gel coats should be prepared according to the test results and construction time. The gel coats should be gelled in 20-40 minutes after the completion of construction. It is generally recommended that the thickness of the mold gel coat is 0.8mm. In order to ensure that the gel coat resin layer thickness is uniformity, the gel coat brushing work will be 2 steps, each layer is 0.3~0.4 mm thick, and the second pass gel coat should be vertical direction of the first pass gel coat. In order to avoid cracking, wrinkling or missing brush, it should be brushed a second time after the first basic gelation. When applying the second gel coat, wear a shoe cover to prevent slipping or adhesion damage.
Fourth, the layer construction process
- FRP materials: Low-alkali and medium-alkali glass fiber products are used above the full waterline of the ship, and glass fiber products are used below the full waterline.
- After the gel coat is sprayed for 1-3 hours, and the gel coat is cured, the surface is basically not sticky or within 12 hours, lay the first layer.
- Apply the prepared resin solution to the mold gel coat, and then lay a layer of chopped strand mat (usually the first layer does not use fiber cloth; prevent the printing marks on the mold surface). Use a brush and roller tool to carefully roll and discharge air bubbles. The glass fiber is layer-by-layer paste-formed by a method of accumulating GC-M-M-R-M-R-M (GC means gel coat, M means chopped strand mat, and R means glass fiber cloth).
4, in the paste process, we must strictly control the amount of resin glue in each layer, not only to fully infiltrate the fiber, but not too much. If amount of glue is high, the bubbles are not easy to be excluded, and the curing heat and the shrinkage rate will be large. Generally, the molding glue amount of the glass fiber chopped strand mat is 65%-70%, and the fiberglass woven roving is 50%-55%. The entire paste process is practiced multiple times. Each time paste 2-3mm, and the lower layer of paste is allowed to be cured after the peak of the curing exotherm.
- When the thickness of the laminate exceeds 3mm -5mm, we must consider the increase of the thickness caused by the glass fiber. The overlap width of the glass fiber joint should be greater than 50mm, and the spacing between the upper and lower glass fiber splicing joints should be greater than 100mm. In the paste making process, in order to ensure that the mold has sufficient strength and avoid deformation of the mold, some strut members, fasteners, can be properly bonded to complete the mold structure.
- The most important thing when laying the layer is cooperation. One person should prepare the resin and curing agent. After the resin is used up, the person need immediately prepare and mix it and send it to the person who lays the layer. There are two groups from the left and right sides to lay up. The auxiliary person must follow the person who is tightly fitting the resin. The action should be faster, otherwise the resin in the staggered position will solidify, and the bubbles are not excluded. That will affects the strength and hardness of the mold (the important point of the layer paste is to drain the bubbles). It takes about 30-40 minutes to cure after the completion of the layup, and the next process can be carried out after 2-3 hours.
Five, mold frame production
- Make a mold release frame: After the lay up finished, we can make the external reinforcement structure of the mold. The purpose is to transfer the external force to the surface of the mold on average to prevent deformation of the surface of the mold.
- Method: First bend the thin wire on the mold. According to the well-defined wire, saw the corresponding long pipe, bend the pipe with a curved pipe, cut the square pipe into a slot, and bend it with a hammer. , the arc matches the mold. A square tube is generally used as a mold, and a round tube is used as a vertical block. After the stripping frame is welded, the mold base should be further trimmed, reinforced, and painted.
- Fixing the mold base: Bonding the mold base to the layup with glass fiber. The specific operation is the same as the layup. After the FRP is cured, it can be demoulded after waiting for a while.
Sixth, stripping, cutting, cleaning, repairing, sanding, polishing
- Stripping: Fix the hooks at the two ends of the mold respectively. The hook and the stripping frame are fixed. Firstly, insert several stripping wedges into the mold and the base mold, and hammer the stripping wedges with a hammer. To evenly apply force to prevent damage to the mold, finally start the hanger and completely separate the FRP mold from the tire mold.
- Cutting edge: reserved edge width of 5cm, cutting and trimming along the edge of the mold.
- Cleaning: clean the burrs inside of the mold, shovel the corners with a plate chisel, and wash one side to facilitate wet sand.
- water sand: wrapped 400, 600, 1000, 1200 sandpaper on the foam block, stained with washing powder water, sanding in one direction, until the mold surface is smooth. The specific operation method is the same as 3.1.
- Repair: Before the water sand, check the inside of the whole mold, and repair the damaged area with gel coat. Then water sand until surface is smooth.
- Polishing: After the mold is completely smooth, apply #1 wax and #2 wax, and then polish.
Seven, waxing on the gel coat
- After the mold is inspected, repaired and polished, waxing begins.
- After waxing, layup gel coat according to customer requirements. Gel coat must be pre-promoted, and the accelerator is between 0.5% and 4%. The amount of curing agent is determined according to the temperature, generally from 1% to 2%.
3, in order to ensure the thickness of the gel coat, it is necessary to brush two layers, horizontally and vertically, to ensure uniformity. The second time is required after the first basic or complete curing.
Eight, inner mold making
- Make the inner mold according to the structure diagram. The outer shell of the product does not leave the mold. First locate with a wooden batten and fix the wooden batten with a glue stick. Fix the wood batten with a fiberglass cloth in the place where the wooden batten is in contact with the outer casing. Make a horizontal plane, and then use the wood board to make the inner mold according to the structure drawing.
- Paste polyboard board, putty: because of the inner mold smooth surface, small components, the polyboard board can ensure a smooth surface, so that you can simply clean the mold, save time, but also can extend the mold life time.
- Around the corners or junctions need to be scraped smooth and rounded with poly-putty base, and make a cardboard to ensure that the rounded corners are the same size.
Nice, cutting edge, cleaning, combining, (bubble)
- Cutting edge.
- Combination: put the finished product and its supporting products together by crane. The edge and bottom are stirred and fixed with the resin plus thixotropic agent and the cut glass fiber, and then filled with bubbles.
- Filled with foam
- According to the shape of the hull, drill a 40mm diameter foam hole (it can be drilled before the combination), cover the hull with a plastic film, leave a foam hole only, and fix the plastic and the foam hole.
- Check if the A and B bins has sufficient material, otherwise feed to the specified position.
- Set the switch of the foam machine (A and B materials must be heated in winter, set the heating temperature of the foam machine to be no less than 30-4O degrees), and the ratio is 1:1.
- Start foaming. Should note that the foaming process is not completed once. Wait for a few minutes for the foam to solidify to prevent the foam from expanding and destroying the product.
- After the foaming machine is filled, the A and B materials should be added to the filter to prevent clogging the pump port. Put the silica gel on the foaming plug, cover the foaming hole to ensure watertightness, internal cleaning, and waxing. Gel coat once or twice.