New technology for automobile painting construction-----Putty blending technology

In the construction process of automobile painting, seasoning is a key technology. The reasonable deployment of various paints is not only conducive to improving production efficiency and quality, but also has very important practical significance for the amount of paint used and the cost of painting. According to the types of materials used in automobile painting, seasoning can be divided into two technologies: putty blending and paint blending.

1. Putty deployment technology

According to the types of putty commonly used in automobile painting, it can usually be divided into self-drying putty, quick-drying putty, drying putty and two-component high-grade putty.

1. Self-drying putty deployment method

Self-drying putty mainly refers to oily putty, ester glue putty, phenolic putty and alkyd putty. The drying of these kinds of putty belongs to the oxidation polymerization type, and the type and amount of drier used in the putty are different, which will affect the drying speed of the putty.

If cobalt, manganese and lead mixed driers are used, the putty will have relatively stable drying performance and storage performance. However, when excessive cobalt and manganese driers are used in the putty, the surface layer of the putty is prone to dryness (dry skin) during storage. Therefore, when blending, for the putty with dry skin, it is necessary to clean the dry skin with a gray knife first, and then fully mix it evenly, so as to prevent the broken dry skin from entering the putty and affecting the quality of scraping. The reconciliation consistency of the putty should generally be determined according to the sequence of putty scraping. For the first two coats of putty, as long as the original barrel of putty has no dry skin, it can be scraped and coated with a gray knife after being poured out, without adding solvent to dilute. But for the final putty, it is usually called delicate putty or thin putty. If it is too thick, it is not conducive to smearing and smoothing. At the same time as the putty is mixed, add an appropriate amount of No. 200 gasoline, turpentine or alkyd thinner to thin it. To make the thinned putty have excellent scraping property, which is beneficial to flattening or thin layer of scraping. For the putty left after use, it can be packed in plastic cloth or bag and soaked in water to prevent the putty from being oxidized and dried in contact with air, resulting in waste.

2. Quick-drying putty deployment method

It mainly refers to two kinds of nitro putty and perchlorethylene putty. Especially nitro putty, it dries quickly, and the surface layer can be dried in a few minutes at room temperature. Therefore, in the blending, the amount of each adjustment should be small, and the putty after blending should be used up within 10 minutes, otherwise the solvent is volatile and the skin will dry out. Generally speaking, before using the nitro putty, you should add a small amount of "-" nitro thinner, fully mix it with a gray knife, and use it immediately. During use, when it is dry due to the volatilization of the solvent, you can reuse the nitro putty. Thinners will dry out and dissolve, and can be used after mixing evenly. For the remaining nitro putty, it should be put into the original bucket immediately, and an appropriate amount of B-grade banana water (x-2 thinner) should be added to the bucket, and it should be sealed and stored so that For the next use. Perchlorethylene putty dries slower than nitro putty, but faster than alkyd putty. Therefore, before use, it should also be mixed with perchlorethylene paint thinner or xylene to make the putty thin and moderate , to facilitate scraping.

3. Drying putty deployment method

Drying putty can be divided into two preparation methods: water quality putty and amino drying putty.

(1) Deploying water quality putty The water quality putty can be diluted directly with tap water. But generally speaking, after the original bucket of water-quality putty is taken out, use a gray knife to fully stir it on the putty board, and then it can be scraped and coated. However, for the water-based putty that has been stored for a long time and has a large consistency or has become soft and hard, it needs to be fully stirred with warm water before it can be used. Especially for the water-based putty that has become light and hard lumps, the lumpy putty should be crushed on the putty board with a shovel, and then add warm water (10%) and stir thoroughly until the water dissolves the putty into a very uniform paste. before it can be used.

(2) Deploying amino drying putty Because amino drying putty is a baking type, it is usually used or stored at room temperature, and the putty is not easy to dry. Therefore, before use, as long as the consistency of the putty in the original barrel is moderate, it can be directly scraped or continuously scraped after being evenly blended without dryness. If the original barrel of putty is too thick and it is inconvenient to scrape it, you can add about 5% amino paint thinner or xylene according to the weight of the putty to adjust to a consistency suitable for scraping.

4. Two-component high-grade putty blending method

At present, the filling and leveling of the bottom layer of automobiles, especially the bottom filling of cars or reworked cars under self-drying conditions, mainly uses two-component putty. This kind of high-grade two-component putty, whether it is domestic or imported, is mostly putty material in a 4kg barrel, and a 100g curing agent is also provided. When preparing this type of putty, generally add 1.5-3 grams of curing agent for every 100 grams of putty material, stir well and use it up within a few minutes. However, due to the difference in the performance of the curing agent for each product, the dryness of the putty after blending is different. For example, the domestic putty can be used for about 10% (about 10 minutes) after blending, while the Japanese-made -- brand putty needs to be dried after blending. Use it up within 10 minutes, otherwise the putty will harden and cannot be used. Therefore, before mixing, make a small sample, that is, mix the putty and curing agent thoroughly according to the specified ratio, scrape a small area, and observe its drying speed and time , and then use this as a basis for deployment and use to avoid waste of putty residue curing.

For the putty that dries quickly through the small sample test, it should be prepared in small but multiple times (the amount of each adjustment should be small), and it should be used up immediately after adjustment to avoid waste. If the drying is slow after a small test, the amount of each adjustment can be appropriately larger, and it can be used up immediately after adjustment. If the putty is thick, you can first add an appropriate amount of polyurethane thinner or methyl banana water x-1 nitro thinner), stir until it is very uniform, then add curing agent in proportion to fully stir, and use it immediately. However, for the storage of two-component putty, it is necessary to store the curing agent and the putty bucket separately, and the curing agent is strictly prohibited from contacting the putty. Otherwise, chronic curing will occur, so special attention should be paid.