1205 Spray painting
INTRODUCTION
Spray coating is the application of liqui borne materials onto a surface. The sprayed material generally has 1 or more of the following functions: filler, primer, colour, decoration and protection.
High gloss, intense and colourful finishes are produced by a combination of meticulous surface preparation, basecoat and topcoat.
The role of the base coat is to supply a monotone backdrop for the high gloss topcoat.
The topcoat is clear and contains platelets or flakes of colour. As it is applied to the basecoat,the platelets or flakes are propelled onto the surface the base coat This produces a topcoat that is multilayered it is rich with colour near the basecoat and almost clear on top. This promotes a glossy, rich and intense colour finish. The majority of spray painting is manually operated. However, there are sufficiently high volumes in the automotive, consumer electronics and industries to spraying systems.
介紹
噴塗是液體物質在表面上的應用。 噴塗材料通常具有以下一種或多種功能：作填充物，底漆，顏色，裝飾和保護。
通過精細的表面處理、底漆和面漆的一系列流程，產生高光澤，強烈和多彩的飾面。
底漆的作用是為高光澤面漆而噴上單色底色。 面漆是清澈的，並含有小碎片(物質的結晶片)或有顏色的薄片。 由於它被應用於底塗層，所以這種碎片或薄片可以促進光澤，豐富而強烈的色彩拋光。大部分的噴塗為手工，但自動噴塗系統大量的應用在汽車、消費電子和工業中。
——————————
TYPICAL APPLICATIONS
Spray painting is used in a vast range of applications including prototyping, repairs, low volume and mass production. It is used in the automotive industry for painting metalwork, and in the consumer electronics industry to colour plastic injection moldings.
典型應用
噴漆廣泛應用於原型，修飾，小批量和大批量生產。 它用於汽車行業的金屬製品的塗裝，以及消費電子行業的塑料注塑成型。
——————————
COMPETING PROCESSES Powder coating is a dry coating technique (page 356) with a finish similar to 2-pack thermosetting paints (see technical description, page 353). It produces a uniform and glossy coating Some techniques are electrostatic and so attract the coating particles to the surface of the workpiece. Combined with collection and recycling of the dry powder, up to 95% material utilization can be achieved with powder coating.
Hydro transfer printing (page 408) can produce effects that were previously spray painted with airbrushes and masking. It is a dipping process and reproduces patterns and print much more rapidly than spray painting.
Vacuum metalizing (page 372) is essentially spray painting with pure aluminium. The aluminium islocked onto the surface of the workpiece by a basecoat and topcoat that are sprayed It produces a highly reflective finish that can be tinted or coloured.
相似程序比較
粉末塗料是一種干塗層技術（第356頁），其表面塗層類似於雙組分熱固性塗料（參見技術說明，第353頁）。 它產生均勻和有光澤的塗層一些技術是靜電的，因此將塗層顆粒吸引到工件的表面。 結合乾粉的收集和回收利用粉末塗料，可以達到95％的材料利用率。
水轉移印刷（第408頁）可以產生以前用噴槍噴塗和遮蓋的效果。 這是一個浸漬過程，複製圖案和塗料比噴漆要快得多。
真空鍍膜（第372頁）基本上是用純鋁進行噴漆，鋁通過噴塗的底漆和面漆被牢牢地附在工件的表面上，產生高度反光的拋光表面，可以染色或著色。
——————————
QUALITY
The quality of surface finish in this process depends on the skill of the operator.
Spray coatings are built up in thin layers, typically between 5 and Too microns (oooo2-o.oo4 in.) thick, with the exception of high-build systems such as combined filler primer.
It is essential that the surface is prepared to a high finish.
The level of sheen on the coating is categorized as matt or egg shell, semi- gloss, satin or silk and gloss. The surface finish may not be critical if the role of the coating is to protect the surface. Protective paints formabarrier between the workpiece and atmosphere to prevent rusting, for example.
However, paint is not integral to the surface and so is prone to peeling and flaking. This is often the result of pinholes or porosity in the coating, which allows the surface of the workpiece to corrode underneath.
Some aesthetic problems include pebbling, orange peeling runs and sags. Pebbling is caused by a coating that is too dry; the thinner evaporates before it has had a chance to settle and smooth. Water borne paints are prone to orange peeling As the name suggests, it is when the surface resembles orange peel.lt is caused by the coating not flowing on the surface, or improper paint thinning. Runs and sags occur when there is too much wet coating material.
品質
表面拋光處理的品質取決於過程中操作者的技術。
噴塗層是由薄層組成，通常厚度在5微米到10微米之間（除了高層建築體系之外） 像是作為組合填料底漆。
表面的高度拋光是非常重要的。
塗層上的光澤度分為霧面或蛋殼光，半光澤，緞面或絲綢和光澤。 如果塗層的作用是保護表面，則表面拋光可能並不重要。 例如，工件與空氣之間的防銹。
然而，油漆僅附著於表面，因此易於剝落和脫落。 這通常是塗層中毛細孔或孔隙的結果，其使塗料下的工件表面被腐蝕。
美感處理的問題包括塗膜粗糙，油漆皺皮/橘皮剝落 和垂流。 粗糙是由於太乾的塗層造成的; 當它在沉澱和光滑之前稀釋劑太早蒸發。 水性塗料容易出現橘皮剝落顧名思義，就是表面類似橘皮，是由於塗料在表面上不流動延展，或塗料太稀造成的。 當濕塗層材料過多時會發生垂流和流口水。
＊涂膜粗糙, Pebbling
＊油漆皱皮，橘皮剝落, orange peeling runs
＊垂流, sages
——————————
DESIGN OPPORTUNITIES
There is an almost unlimited range of colours and finishes for paints. Standard colour ranges include RAL and Pantone. Colour is supplied by pigments, which are solid particles of coloured material.
They can be replaced or enhanced by platelets of metallic, pearlescent,dichroic, thermochromic or photoluminescent materials. Entire surfaces can be painted, including different materials, to produce seamless finish. Otherwise,masks and templates can be used to create different colours patterns, logos and text.
Masks and templates can made from tape, paper or cardboard for example. There are many different techniques used to apply decorative effects.
For example, overlaying colours and tones using different spraying techniques will produce graduation, shading and mottling. Marbling is achieved by draping materials over a wet topcoat which drags and smears it overthe basecoat covering it with a clear topcoat seals in the pattern with dramatic effect (see image, page 350) .
A flock finish can be achieved by spraying adhesive followed by fibres of cotton, papersilk or similar material.
There is even avarnish employed to produce a cracked topcoat Crackle varnish is painted over a colour. onto this is applied a contrasting colour typically gold on top of black The crackle varnish allows the topcoat to crack but not peel as it dries and contracts. The effect is similar to antique gold leaf.
設計機會
漆料幾乎沒有色彩上及拋光的限制。標準色彩範圍包括RAL和Pantone。顏色由顏料提供，顏料是有色物質的固體顆粒。它們可以被金屬，珠光，二向色，熱致變色或光致發光材料的小碎片(物質的結晶片)代替或增強。整個表面可以由塗漆和不同的材料生產無縫拋光面。或是可以使用遮蓋板和模板來創造不同的顏色模式，商標和文字。
遮蓋板和模板可以由膠帶，紙或紙板製成。有許多不同的技術用於裝飾效果。
例如，使用不同的噴塗技術疊加顏色和色調會產生漸變，陰影和斑駁。花紋通過將材料鋪在濕面漆上來呈現，該面漆拖曳並塗抹在基礎塗層上，並以透明的面漆蓋過，並具有顯著的效果（參見圖像，第350頁）。
植绒塗装＊＊＊可以通過噴塗粘合劑，及棉，紙或類似材料的纖維來呈現。
甚至還有用來生產裂紋表面的化學漆。在這上面應用了一種對比色，典型的是黑色的金色。裂紋漆使面漆開裂但不會因為乾燥和收縮而剝落。效果類似於古董金箔。
——————————
DESIGN CONSIDERATIONS
The opportunities for paint effects and quality are heavily dependent on the skill of the operator. With the correct preparation and basecoat almost any combination of materials can be coated.
An important consideration is that spraying applies coatings in line-of-sight, so deep undercuts and recesses are more difficult to coat evenly.
Electrostatic techniques draw more spray to the surface, but there is always overspray. There is no size restriction. If the part will not fit in a spray booth or cannot be moved then it can be sprayed on site. For example, very large aeroplanes are sprayed in booths that are modified aircraft hangers.
設計注意事項
油漆效果和質量在很大程度上取決於操作員的技能。 精確的準備和底漆幾乎可以塗覆任何複合材。
一個重點需要特別注意的若是維持視平線方向的噴塗，會使深的凹陷難以均勻塗覆。
靜電技術＊＊＊將更多的噴塗到表面上，但總是會產生過度噴塗。 這沒有大小限制。 如果部件不能置入噴漆室內或不能移動，則可以在現場進行噴塗。 例如，非常大的飛機掛在為它而修改的棚子內的架子上噴漆。
——————————
TECHNICAL DESCRIPTION
Spray guns are gravity fed, suction fed or pressure fed. The diagram illustrates a gravity fed gun. They all use a jet of compressed air to atomize the paint into a fine mist. The trigger controls the valve through which the pressurized air flows. The atomized paint is blown out of the nozzle and makes a cone shape.
Pressurized air is blown out of the cap onto the cone, which forces it into an elliptical shape. This gives the operator more control because the shape can be adjusted to suit the application and required film thickness. The coating is applied onto the surface in overlapping strokes. Suction feed guns have the paint pot on the underneath instead of on top. The paint is drawn into the jet of air by suction. Pressure feed systems are supplied by a paint pot that is connected to the spray gun via a flexible pipe. The paint is pressurized to force it into the spray gun.
Conventional spray guns operate at approximately 3.45 bar (50 psil. This depends on the type and viscosity of paint.
Painted surfaces are nearly always made up of more than 1 layer. If necessary the surface is prepared with filler and primer. The primer may provide a surface onto which paint will adhere such as an acidic etch primer used to make a good bond with metallic surfaces. Some topcoats require a basecoat to provide a coloured backdrop. opaque topcoats can be applied directly onto the primer.
Paints are made up of pigment, binder, thinner and additives. The role of the binder is to bond the pigment to the surface being coated. It determines the durability, finish, speed of drying and resistance to abrasion These mixtures are dissolved or dispersed in either water twater bornel or a solvent (solvent borne). The ingredients of varnish, lacquer and paint are essentially the same. Lacquers and varnishes can be pigmented, tinted or clear.
Another type of paint, 2-pack, has emerged. They are so called because they are made up of 2 parts the resin and the catalyst or hardener. They are thermosetting and bond to the surface in a 1-way reaction. They are also hazardous to use because they contain isocyanates.
Water-borne paints are made up of pigment and binder of acrylic emulsion vinyl emulsion or polyurethane, dissolved or dispersed in water. They are applied to the surface and dry as the water evaporates and the binder adheres to the workpiece. They are flexible and so are suitable for painting wood and other materials that are likely to expand and contract in their lifetime. Solvent-borne paints (also known as alkyd and oil-basedl are made up of pigment and a binder of alkyd resin dissolved in thinners. Solvent-based paints are slow drying and off-gas polluting and harmful volatile organic compounds (vocs].
Additives provide specific qualities such as quick drying, antifouling, anti-mould or antimicrobial properties. There are 2 different types of enamel painting. The first is similar to the above, except that it is a mixture of paint with a high level lacquer, which produces a high gloss finish. The second is applying a coating of glass, which is bonded onto the surface of the workpiece at high temperatures labove the melting point the glass. ThisAdditives provide specific qualities such as quick drying, antifouling, anti-mould or antimicrobial properties. There are 2 different types of enamel painting. The first is similar to the above, except that it is a mixture of paint with a high level lacquer, which produces a high gloss finish. The second is applying a coating of glass, which is bonded onto the surface of the workpiece at high temperatures labove the melting point the glass. This limits of the finish to materials with a higher melting point ceramics and instance. metal, for instance.
技術說明
噴槍採用重力進料、吸力進料或壓力進料。 該圖說明了重力進料槍。 使用壓縮空氣噴霧將油漆霧化成細霧。噴槍板機控制壓縮空氣流過的閥門。 霧化的塗料從噴嘴吹出並呈錐形。 加壓的空氣從蓋子吹到錐體上，迫使它變成橢圓形狀。 由於可以調整形狀以適應應用和所需的薄膜厚度，因此操作員可以進行更多的控制。 塗層以重疊的行程施加到表面上。 吸料槍的底部有油漆罐，而不是頂部。 油漆被抽吸到空氣射流中。 壓力供給系統通過彈性管連接到噴槍的油漆罐。 油漆被加壓迫使它進入噴槍。
傳統的噴槍在大約3.45BAR＊＊＊（50psi）下工作，這取決於油漆的類型和黏稠度。
被噴塗的表面幾乎都是由一層以上的塗料組成。 如有必要，表面可由填料和底漆構成。 底漆可以使油漆將黏附在工件的表面，例如能與金屬表面良好結合的酸性蝕刻底漆。 一些面漆需要底漆來強化漆料色彩。 不透明的面漆可以直接塗在底漆上。
塗料由顏料、黏合劑、稀釋劑和添加劑組成。 黏合劑的作用是將顏料粘合到被塗覆的表面上。 它決定了耐久性，拋光程度，乾燥速度和耐磨性。將這些混合物溶解或分散在水槽或溶劑（溶劑型）中。 清漆，漆和油漆＊＊＊的成分基本相同。 漆和清漆可以被著色，染色或清除。
另一種類型的油漆，為2包裝。 正如他們的名稱，因為他們是由2部分組成，樹脂和催化劑或硬化劑。 它們是熱固性的並以單向反應結合到表面上。
由於含有異氰酸酯，它們是有危險性的。
水性塗料由丙烯酸乳液、乙烯基乳液或聚氨酯的顏料和黏合劑＊＊＊組成，溶解或攪混在水中。 它們被平塗到表面並乾燥，當水分蒸發即黏合劑附著在工件上。 它們是有彈性變化的，因此適用於上色魚木材和其他有生命期間可能膨脹和收縮的材料。 溶劑型塗料（也稱為醇酸樹脂和油基塗料）由顏料和醇酸樹脂粘合劑組成，溶於稀釋劑。溶劑型塗料是乾燥慢，會產生揮發性有機化合物（VOC）會導致污染且是有害的。
添加劑具有快速乾燥，防污，防黴或抗菌等特性。 有兩種不同類型的琺瑯噴塗法。 第一種與上述類似，不同之處在於它是高等級漆的混合物，產生高拋光度。 第二種是在高溫下（玻璃熔點以上）施加玻璃塗層，該玻璃塗層黏合在工件表面上。例如，對於具有較高熔點的材料拋光上有所限制，例如陶瓷和金屬。
BTW-----------------------------------------------------------------------------------
油漆施工術語 42. 無氣式噴塗 (AIRLESS SPRAY)︰ 不以空氣噴塗，係施壓力於塗料本身而由噴咀使塗料以霧狀噴出塗裝。 43. 混氣式噴塗 (AIR ASSISTED / AIRLESS SPRAY)︰ 以無氣式噴塗改良，加入少許之空氣，改良霧化效果及塗料之節省。 44. 水洗塗裝櫃 (WATER WASH / SPRAY BOOTH)︰ 塗裝時用來收集殘餘之抽氣裝置，原理是利用流水牆吸引塗料，達到防止塗料飛散污染目的。 45. 靜電塗裝 (ELECTROSTATIC SPRAY)︰ 於塗料與物體之間施加靜電壓，使塗料霧吸引至物體而塗裝的方法，此法可大幅減低塗料浪費。 46. 紅外線烘乾 (INFRA-RED DRYING)︰ 利用紅外線燈管照射塗膜之表面，而加熱乾燥的方法。 47. 白化 (BLUSHING)︰ 塗膜含有水分或其他液體，塗膜之顏色較淡白且有白霧現象，一般高濕情形噴塗較易產生。 48. 橘皮肌 (ORANGE PEELING)︰ 塗膜表面不平坦，如橘子，柳丁，柚子的果皮狀，呈現凹凸狀態，主要原因油漆不能流展平滑。 49. 粗糙塗膜 (PEBBLING)︰ 噴塗之面產生砂粒狀凹凸且光澤度不佳，此為塗裝黏度過高或乾燥過快，溫度高，噴塗不當所致。 50. 粒狀塗膜 (SEEFINESS)︰ 塗膜表面附著灰塵、飛絮、砂粒等異物，原因有塗料不潔物，噴塗挾雜物，未指觸乾燥塗面落下之灰塵等。 51. 下流、垂流 (SAGS、RUNS)︰ 塗膜太厚或塗膜不均，黏度過低在側面之塗裝最容易產生，噴塗距離之不當，噴槍之運行速度不當等。 52. 砂紙傷痕 (SAND SCRATCHES)︰ 下地及舊塗膜硏磨時的砂紙傷痕，一般是硏磨方法錯誤及未按規定使用之硏磨紙，下地未充分乾燥而予硏磨，塗料黏度過低。 53. 吸陷 (目陷) (SINKING-IN)︰ 上塗塗佈之後塗膜吸入下地，表面呈無光澤，主要原因︰下塗未乾即硏磨，多孔未充分處理，灰塵未徹底清理噴上塗，上塗之塗佈量太少或黏度過低，使用不良的塗料。 54. 反撥，魚眼 (CISSINS，FISH EYE)︰ 塗料被反撥，塗膜產生凹凸不平，或塗膜部分不附著，主要被塗物或塗料有水分、油分、腊或矽油未清除，及硏磨之灰塵污布等引起。 55. 氣泡 (BUBBLING)︰ 塗膜內含有氣泡，原因︰填充不良內有空氣，塗料與被塗物表面溫差過大，溶劑使用不當，過度厚塗，塗料中含有氣泡，塗裝面含有水分，灰塵、矽油，壓縮機混有油，水分，溶劑未揮發施予強制乾燥。 56. 皺紋 (WRINKING)︰ 表面收縮向上膨脹，形成皺紋的狀態，原因︰一次塗太厚表面急速乾燥，工廠溫度不適合，下塗未乾進行上塗並且進行強制乾燥，下塗與上塗搭配不同種類的塗料。 57. 龜裂、裂紋 (CRACKING、CHECKING)︰ 通常發生在上層塗膜，此現象均在塗膜上生成線狀，多角狀或不定狀，一般原因有︰木材含水率過多，一次即厚塗，硬化劑添加過多，耐候性差的塗料，不同塗料組合錯誤。 58. 針孔 (PINHOLE)︰ 塗膜出現如針狀小孔的狀態，有時成密密麻麻的小孔狀，原因︰填充劑底漆乾燥不完全，塗裝後急速乾燥，溫度過高一次厚塗的場合，使用不良的稀釋劑。 59. 黃變 (YELLOWING)︰ 淺色或白色塗膜，經一段時間或受熱後呈現帶黃的現象，主要原因是環境因素，日曬、塗膜老化分解，高熱乾燥，一般若需防止應考慮使用非黃變塗料。 60. 光澤不均 (UNEVEN GLOSS)︰ 塗面之光澤不均勻，此為噴塗者操作不良所致。 61. 剝離 (SCALING)︰ 塗裝後塗膜附著不良，經少許外力或甚至未經外力，即呈現塗膜脫落現象，原因︰使用品質不良的塗料，或塗物附著油、水、矽油等，搭配不良下塗膜不適合上塗的場合。 62. 回黏 (REVISCID)︰ 塗膜乾燥後，塗面一部分或全部再發生黏著性之狀態，一般發生因為︰溶劑揮發遲緩，乾燥不完全，環境溫度高，硬度低的塗面，性質不同塗料共用等。