静电喷塑工艺常见问题及解决办法

Common problems and solutions of electrostatic spray technology

1

One

针孔

pinhole

★主要原因：①板面锈蚀；②镀锌底材含氢离子；③前处理后发黄； ④工件磷化后，水洗不干净，尤其在工件四周表现为圈状针孔；⑤阴阳离子 交换树脂脱盐水呈酸性；⑥粉末质量。

The main reasons are: (1) the corrosion of the plate surface; (2) the hydrogen ion of the galvanized base material; (3) the yellowing after pretreatment; (4) after the phosphating of the workpiece, the water washing is not clean, especially in the circle around the workpiece; (5) the anion exchange resin of the Yin and Yang exchange resin is acidic; and the quality of the powder is the quality of the powder.

★解决措施：①前处理后及时烘干，立即喷涂；②脱氢处理200℃左右，2h； ③调整前处理液参数，注意游离酸浓度不宜过高；④换成新鲜水，清洗喷嘴， 使水压＞1.5bar；⑤停用，暂以自来水代替，化验 pH 值，要求达到 6～7； ⑥取新鲜样粉，按标准条件固化以检验粉末质量。

Measures: (1) drying in time and spraying immediately after pretreatment; 2. Dehydrogenation treatment at about 200 degrees C, 2h; 3. Adjust the parameters of the pretreatment liquid and pay attention to the free acid concentration should not be too high; (4) change into fresh water, clean the nozzle, make water pressure > 1.5bar; stop using tap water instead, test pH value, to reach 6~7; _Takefresh sample powder and solidify according to standard conditions to check the quality of powder.

3

Three

缩孔

Shrinkage hole

★主要原因：①粉末生产过程中进水或油。其缩孔分布均匀，呈细小圆坑 或大针眼；②喷涂过程中混进其他粉，因不相容造成缩孔；③外界干扰物质 污染喷涂系统包括工件，尤其是车间里存在含硅脱模剂和放水剂；④铸件 表面有大而深地孔；⑤涂层出现圆坑，且较大，俗称“鱼眼”；⑥压缩空气 油含量高。

9733 The shrinkage cavity is evenly distributed, with small round pit or large needle eye; (2) mixing other powder in the spraying process and causing shrinkage due to incompatibility; (3) the external interference material pollution spraying system includes the workpiece, especially in the workshop, and there is a silicon release agent and water release agent in the workshop; (4) the surface of the casting has large and deep holes; and the coating appears round pit and larger. _Compressedair oil content is high.

★解决措施：①联系厂家换粉；②换粉清理粉房须彻底，最好整理出清理 和检查程序；③仔细检查喷粉现场，排除这些干扰物质，严格规章制度，严防带入这些干扰物品；④铸件可预热，预热温度和时间视材质 和厚度而定；⑤脱脂段调整参数，干燥和固化烘道污染须清洗，检验升降机 和橡胶皮带是否污染粉末；⑥检查压缩机的过滤器，加装油水分离器，每班定时排放水。

Measures: (1) contact the factory to change powder; (2) the powder cleaning room should be thoroughly cleaned and inspected procedures; (3) check the powder site carefully, eliminate these interfering substances, strict rules and regulations, and strictly prevent them from entering these interfering articles; (4) the casting can be preheated, the preheating temperature and time depend on the material and thickness; 5 Degreasing section adjustment parameters, dry and curing drying Road pollution must be cleaned, check whether the lift and rubber belt pollution powder; 6. Check the compressor filter, add oil water separator, every class schedule discharge.

3

Three

涂层局部或大面积脱落

Partial or large area off of the coating

★主要原因：①底材表面有锈层，未除尽；②水洗尤其前处理后水洗不干 净；③底材表面除油不彻底；④悬挂链上润滑油滴落到工件上；⑤镀锌板起 泡及涂层脱落。

The main reasons are: (1) there is a rust layer on the surface of the bottom material, which is not removed; (2) the washing is not clean, especially after the pretreatment. (3) the surface of the bottom material is not thoroughly oil; (4) the lubricating oil on the suspension chain drops to the workpiece; 5.

★解决措施：①除锈应彻底；②检查水洗流量、水质和喷嘴，检查水洗流 量和压力；③采用化学除油较适于动植物油，不适于矿物油时，多用碱除 油，除油后加强水洗注意水质；④检查润滑油质量指标，必要时更换耐温 更高的润滑油或在易滴落处下面安置受槽；

Measures: (1) rust removal should be thorough; (2) check the flow of water, water and nozzle, check the flow and pressure of water, and use chemical degreasing more suitable for plant and plant oil, not suitable for mineral oil, use alkali to remove oil, and strengthen water washing to pay attention to water quality after oil removal; (4) check lubrication oil quantity index and change the temperature to be higher when necessary. The lubricating oil or the receptive groove is placed under the dripping place.

4

Four

涂层发黄变色

Yellowing and discoloration of coating

★主要原因：①烘道或烘箱设定温度过高；②直接燃气进入烘箱或烘道；③工件在烘道或烘箱里停留时间过长，或输送链停止运转；④粉末质量；⑤工件反复烘烤 2 次以上；⑥涂料严重变色。

Main reasons: (1) setting the temperature of the oven or oven is too high; (2) the direct gas enters the oven or the drying Road; (3) the workpiece stays in the drying or oven for a long time, or the conveyor chain stops running; (4) the quality of the powder; (5) the workpiece is baked over 2 times repeatedly; and the paint is discoloring seriously.

★解决措施：①了解正常的固化条件并加以调整；②加装热交换器；③了解烘烤条件，生产时密切注意输送链运转是否正常，如需停止生产，应将所有工件烘烤结束并下料；④供粉厂提供不同烘烤条件下的样板，供喷涂时参考；⑤尽量一次烘烤完成，须二次烘烤的工件应集中处理，并要先确定重复烘烤的条件；⑥检查烘烤温度是否过高如＞230℃或更高。检查粉末的耐温性。

Measures: (1) to understand the normal curing conditions and adjust it; (2) adding heat exchanger; (3) to understand the baking conditions and to pay close attention to the normal operation of the conveyor chain. If you need to stop the production, all the work pieces should be baked and laid off. As far as possible a baking finished, the two baking workpieces should be concentrated, and the conditions of repeated baking should be determined first; (6) check whether the baking temperature is too high, such as > 230 or higher. Check the temperature resistance of the powder.

5

Five

光泽不稳定

Luster instability

★主要原因：①光泽偏低；②光泽偏高；③光泽上下波动；④光泽突然降低。

97

★解决措施：①检查烘烤温度是否偏高，或烘烤时间是否偏长，向粉厂咨询烘烤条件，另可检查粉末的含水率和喷房的温度；②核定烘烤温度和时间，可与①对照，检查光泽、工件厚度及烘烤条件；③是否直接燃气炉，检查是否有混粉及喷涂环境温度变化。检查烘道及烘箱温度是否稳定；④检查温度是否失控，检查空压系统、油水分离器工作是否正常，检查是否混入其他粉。

Measures: (1) check whether the baking temperature is high, or whether the baking time is long or not, consult the baking conditions for the powder plant, check the moisture content of the powder and the temperature of the spray room, and check the baking temperature and time, check the luster, the thickness of the workpiece and the baking strip, and check if the gas furnace is direct. There is no change in the ambient temperature of mixing and spraying. Check whether the temperature of the oven and oven is stable; (4) check whether the temperature is out of control, check whether the air pressure system, the oil water separator work is normal, and check whether it is mixed with other powder.

7

Seven

局部不均匀，流平度不稳定

Local inhomogeneity, instability of flow flatness

★主要原因：①由膜厚不均匀引起；②粉末粒度前后变化大；③高压击穿；④文丘里管磨损，出粉不均；⑤使用的输粉管与设备不适应；⑥输送链有挤动现象，走速不均；⑦流化桶中多孔板损坏或局部堵塞。

The main reasons: (1) caused by the uneven thickness of the film; (2) the powder particle size before and after large changes; high pressure breakdown; (4) Venturi tube wear, powder uneven; (5) the use of powder pipe and equipment do not adapt; (6) the conveyor chain has the phenomenon of extrusion, walking speed is not uniform;

★解决措施：①加强膜厚控制，检查喷粉系统供粉、回收、喷枪电压等是否正常；②通知粉末厂检验；③降低供粉电压，但必须保证正常的膜厚，可增加出粉气压或扩大喷枪与工件的距离；④检查并更换；⑤联系设备供应商，检查并更换；⑥检修悬挂链，使之匀速；⑦检查流化情况，并检修多孔板。

Measures: (1) strengthening the thickness control of the film, checking the powder supply, recovery, and the voltage of the spray gun in the powder injection system; (2) notify the powder plant to check it; to reduce the power supply voltage, but to ensure the normal thickness of the film, increase the pressure of the powder or expand the distance between the spray gun and the workpiece; (4) check and replace it; 5 contact the equipment supplier, Check and replace; repair overhanging chain and make it uniform; check fluidization and repair perforated plates.

7

Seven

砂  粒

Sand grains

★主要原因：①均匀密集出现；②呈突起的圆形，数量不多；③少量砂粒， 大小不一；④工件表面有杂质，有时呈放射状或细长型；⑤少量黑色颗粒。

The main reasons are: (1) uniform and dense; (2) a circular shape with little quantity; 3. A small amount of sand, the size is different; (4) the surface of the workpiece has impurities, sometimes radiate or slender type; 5.

★解决措施：①测定膜厚是否符合工艺要求；②检查粉末质量，是否存在胶化粒子，另检查前处理后工件表面是否干净无杂质；③多由环境不干净引起，必须时刻保持环境的清洁；④检查粉末质量，操作员尽量不穿戴易掉细小纤维的衣裤和手套等，及时筛粉；⑤烘道中有杂质如胶化物飘落到干净上。定期清理烘道。

Measures: (1) determine whether the thickness of the membrane is in line with the technical requirements; (2) check the quality of the powder, whether there is a gelatinized particle, and check whether the surface of the workpiece is clean and free after the pretreatment; (3) the environmental cleanliness is caused by the uncleanness of the environment. In addition, there are impurities such as gelatinized material falling to clean. Clean up the oven on a regular basis.

8

Eight

喷枪不出粉或出粉量越来越少

No powder or less powder in a spray gun

★主要原因：

Major reasons: