1. The quality of the coating of the gel coat layer is directly affecting the external quality of the product as well as the weather resistance, water resistance and corrosion resistance of the chemical medium. Therefore, the coating of the gel coat layer should be strictly controlled.
1. When configuring gel coat resin, it must be fully mixed, especially when using pigment paste, if the mixing is uneven, spots and streaks will appear on the surface of the product, which not only affects the appearance but also reduces its physical properties; when the curing agent is added, it must be stirred evenly. Avoid surface wrinkles, cracks and other defects caused by uneven curing.
2. The gel coat can be sprayed with a brush or a special spray gun. If the gel coat viscosity is too high, an appropriate amount of styrene can be added to adjust the viscosity and make up for the styrene lost during the operation, but the amount of styrene should be controlled according to the process requirements. .
3. The thickness of the gel coat layer should be controlled between 0.3~0.5mm, and it should not be too thick or too thin. It is usually controlled by the amount of gel coat used per unit area, that is, the amount of gel coat is 350~500g/m2.
4. The gel coat should be sprayed evenly to avoid local accumulation of the gel coat.
5. The curing degree of the gel coat layer should be well controlled, and the paste time of the reinforcement layer should be accurately determined.
2. FRP layer paste
1. When pasting, first use a brush to evenly coat a layer of resin on the gel coat layer, then lay a layer of cut reinforcement material, and then use a forming tool to brush it flat, press it tightly, and make It should be closely combined, and pay attention to eliminate air bubbles, so that the glass cloth is fully impregnated. Do not lay two or more layers of reinforcing materials at the same time. Repeat the above operation until the design thickness or process requirements are reached.
2. If the product's geometric dimensions are more complicated, the reinforcement material is not laid flat in some places, and the bubbles are not easy to be discharged. You can use scissors to cut the gap and make it flat. You should pay attention to the staggered position of each layer to avoid loss of strength.
3. The direction of the fabric fiber is different, and the strength is also different. The direction and layering method of the reinforcing material used should be in accordance with the process requirements.
4. When thick-walled products are pasted, they are usually formed multiple times to avoid the product from becoming scorched and discolored due to poor heat dissipation, or even affecting the physical properties of the product.
3. Curing and demoulding-The FRP products produced by the company's hand lay-up workshop use room temperature and pressure curing resin system. The general requirements for the hand lay-up molding operating environment: normal temperature is not less than 15 ℃, humidity is not more than 75%, under normal conditions, curing It is divided into three stages: gelation, curing and aging.
1. Gel: The time it takes for the resin from adding the curing agent to lose fluidity. The paste operation must be completed before the gel.
2. Curing: the process from pasting completion to product demoulding.
3. Maturation (post-curing): the process that a product undergoes to reach its best performance after a long period of time after demoulding.
The product can be demolded when it is cured to the demolding strength, generally 15-25 minutes. Demolding is a key process in the process of hand lay-up FRP products. The quality of demolding directly affects the product quality and the effective use of molds. You can use the mold release tool configured in the workshop, but it is prohibited to knock the mold with a hammer or the like. After demoulding, place the product in the designated location to wait for the completion of subsequent processing.
Fourth, post-processing-a series of processing tasks such as cutting, trimming, processing, hole opening, trial assembly, inspection, packaging and so on are required after the hand-laid FRP product is demoulded.
1. Trimming: Cut the semi-finished product to the specified regular shape in accordance with the relevant documents. Cutting and punching is the responsibility of a dedicated person. Please do not arbitrarily cut and punch without unassigned personnel.
2. Processing: After the FRP products are cut, further processing, that is, edging, deburring, cutting, opening, etc., use special tools to trim the cut surface and corners of the FRP products, which has reached the customer requirements (test standard) .
3. Inspection: The inspector will carry out quality inspection on the repaired product. The operator is responsible for repairing the defective product. After the repair is completed (the repair and polishing are completed), it will be sent to the inspection until the inspection is qualified, and the inspection requirements are not met in the end. Products are scrapped.
4. Packaging: Clean up, paste the certificate, spray the words and other processes on the products that pass the inspection. After completion, pack according to the designated process. After packaging, the product should be placed in the designated location and waiting for shipment.
Note: The material of glass fiber reinforced plastic products is relatively brittle, and it needs to be handled lightly. It is strictly forbidden to knock or impact the product, which may damage the product.