درست همانطور که مقررات دولتی درباره مسافت پیموده شده بنزین در دهه 70  به موتورهای پیشرفته موتورهای پیشرفته امروز را تقویت می کند،  مقررات دولتی مربوط به آن است انتشار VOC از خطوط پوشش موجب توسعه برخی از آنها شده است مواد  حمل شده با آب و آب قابل توجه

Just as government regulations concerning gasoline mileage in the ‘70s helped spur today’s improved automobile engines, so government regulations concerning VOC emissions from coating lines have spurred the development of some

remarkable waterborne and water based coating materials

در حال حاضر تولید کنندگان باید بدانند چگونه می توانند عملیات خود را برای استفاده از این مواد جدید به طور موثر تبدیل کنند. این به این معنی است که آنها باید بدانند چه تجهیزات کاربردی مناسب است و چه بهتر از آن برای استفاده از آب دریاها استفاده شود

Now manufacturers need to know how to convert their operations to use these new materials efficiently. This means that they need to know what application equipment is suitable and how best to use it to apply waterbornes

A likely first question is “What is the best way to apply a waterborne material?”

The answer is “There is no best way.” The process that works best in a particular application with a solvent-based coating will usually continue to be the best after converting the application to a waterborne coating. The dynamics of getting material from the applicator to the part are similar whether the material contains mostly solvents or mostly water.

انتخاب اتمایزر

ATOMIZER SELECTION

Most coating material applicators break the material up into fine droplets or particles, which are then carried through the air to the part being coated.

The process of breaking up the material is called atomization, and the equipment that does the atomization is called an atomizer.

Typical atomizers are air spray guns, rotary atomizers, and disks. None of these is “best” for all waterborne applications.

 Instead, the shape of the part being coated, the coverage required, and the production rate determine the best atomizer for a particular application using waterbornes, just as they do with solvent-based materials.

To illustrate the importance of part configuration on atomizer selection, consider a simple box-like part, open on one end, requiring paint on both the inside and outside surfaces. The outside of the box might best be painted with a soft spray using electrostatics to get good part coverage, high transfer efficiency (TE), and good wrap.

A rotary atomizer with electrostatics would be a good choice for the outside of the box.

The rotary atomizer and electrostatics would be a poor choice, however, for

the inside of the same box because the Faraday cage effect caused by the electrostatics and the walls of the box would actually keep most of the paint out of the box.

A better choice for the inside of the box would be an airless spray atomizer. Airless spray uses the momentum of the paint particles to get the paint to the part, rather than electrostatic attraction.

The point is that a manufacturer who has spent a lot of time perfecting the

coating application process for solvent-based material should stick with that process when converting to waterbornes,

 if the latest technology and good equipment are already in place and good TE is being obtained.

Sometimes a particular waterborne coating formulation may need to be

modified slightly to accommodate the atomizer.

 For example, an emulsion

may tend to separate when subjected to severe centrifugal force on a spinning rotary atomizer cup.

Does this mean that you don’t have to change anything in order to convert

to waterbornes?

No, it doesn’t. Even though the basic application process may not change, some of the specific pieces of equipment used for that process  may not be suitable for waterborne materials. Metal parts may corrode. Seals may swell or leak.

مواد ساخت

 Waterbornes فولاد زنگ زده و در برخی موارد به آلومینیوم حمله می کندحتی قطعات برخی از قطعات فولادی ضد زنگ می توانند توسط بعضی فرمولاسیون آسیب دیده باشند. به عنوان مثال، فولاد ضد زنگ 400 سری می تواند در طول زمان در تماس با فرمول بسیار اسیدی باشد.از سوی دیگر قطعاتی که از فولاد ضد زنگ 316 ساخته شده اند، با بیشترین مقدار آب در آمده اند.

CONSTRUCTION MATERIALS

Waterbornes rust plain steel and in some cases attack aluminum. Even stainless-steel parts can be damaged by some formulations. For example, 400 series stainless steel can dissolve over time in contact with a highly acidic formulation.

 On the other hand, parts made from 316 stainless steel hold up well with most waterbornes.

This means that at least some of the application equipment will need to be

replaced when a system is converted to waterbornes.

 Piston pumps made of plain or alloy steel have to be replaced with pumps made of stainless steel. Pipes and distribution systems need to be made of corrosion-resistant materials such as stainless steel.

Atomizers should contain only stainless steel or plastic wetted parts. Parts made from aluminum will perform satisfactorily for some waterborne materials, but will corrode quickly in contact with others.

Some waterborne formulations can even become “explosive” in contact with aluminum.

Seals in atomizers and pumps need to be changed if they are not compatible

with the waterborne material.

 There is no single best seal material for waterbornes because the formulations vary so much.

 In some cases, the seals in equipment used for solvent-based coating materials are also suitable for waterbornes. For example, Buna-N is suitable for some solvent-based paints and is also a good choice for many waterbornes.

One caution about reusing equipment from a solvent-based coating operation for waterbornes, a surprising amount of “dirt” from the old coating material can turn up in the new coating material after the conversion to waterbornes. A few filters in the fluid lines can prevent a lot of downtime due to plugged nozzles and orifices.

As with the coating application process and most of the equipment, the physical plant does not necessarily need to change in order to convert to waterbornes.

Often the formulation of the waterborne material can be tweaked a little to accommodate the facility. For example, the drying time for a waterborne primer may need to be adjusted for the time available before the color coat is applied.

The TE can drop after converting to waterbornes even though the application process is the same and much of the equipment is unchanged. This is especially true if the application process includes atomizing the material.

ELECTROSTATICS

All spray guns and centrifugal applicators, like rotaries and disks, atomize the coating materials and propel the atomized particles toward the part being coated.

 With these devices, all the particles that are not aimed directly at the part will miss it and be wasted. The waste can be minimized and TE improved if the atomized coating material is given an electrical charge that is opposite in polarity to the charge on the part being coated.

Opposite electrical charges attract and some of the material that would miss the part entirely instead gets drawn to it by the electrical forces.

The technique is called electrostatics and has been used for years by painters and coating applicators to improve the TE of their operations.

Until recently, most coating materials were solvent based and did not conduct electricity readily. This made it easy to use electrostatics with these materials by simply placing a high-voltage electrode in the coating material at the atomizer nozzle. The coating material picks up a static charge of electricity as it is atomized.

Waterborne coating materials conduct electricity much more readily than solvent-based materials, however, and the electrical charge drains off down the paint hoses.

None of the charge gets into the particles of atomized coating material, so there is no electrostatic attraction between the particles and the part being coated. Without electrostatics, TE drops to unacceptably low levels.

چالش در تبدیل به آب در TE قابل مقایسه  با این مواد رسانا مشابه  مواد مبتنی بر حلال نارسانا که  جایگزین آنهاست می باشد.  

The challenge in converting to waterbornes is getting comparable TE with these conductive materials as with the nonconductive solvent-based materials they replace.

This means finding a way to get the electrostatic voltage into the atomized particles rather than letting it drain away through hoses and equipment made conductive by the waterborne coating material.

Any equipment that contacts an electrical ground, such as a pipe or a damp concrete floor, provides an electrical pathway that drains off the electrostatics.

این به این معنی است که الکترواستاتیک در سیستم آبرسانی کار نمی کند مگر اینکه تمام تجهیزات مرطوب جدا از زمینه های بالقوه باشد.

This means that the electrostatics won’t work in a waterborne system unless all the wetted equipment is

isolated from potential grounds.

SYSTEM ISOLATION

Waterborne systems are commonly isolated in one of three ways. (1) Complete isolation of all equipment that contacts wet coating material. (2) Isolation of the charging electrode from the wet coating material. (3) Isolation of only the atomizer and its feed hose by using a voltage blocking device. Each method has advantages and disadvantages.

Complete Isolation

The advantage of completely isolating the entire application system is that the

coating material can be directly charged with electrostatic voltage.

If isolation is successful, the resulting TE will be the highest possible for the specific application. The exact TE that can be achieved in a specific application depends on the part geometry, line speed, application equipment, and other factors, the same

as it would with a solvent-based coating material.

To isolate a complete waterborne system, every pump, tank, pipe, atomizer, or other piece of equipment that sees wet coating material must be set on a plastic table or hung from a plastic rod or stuffed in a plastic pipe sleeve.

 Suitable common and inexpensive plastic materials for this purpose include polyvinyl chloride

(PVC), polyethylene, and polypropylene. Teflon, some nylons, and Delrin are also good isolation materials for high voltage, but are relatively expensive

هوا خشک یکی از بهترین مواد انزوا است. 12 اینچ شکاف هوا تجهیزاتی را که با ولتاژ الکترواستاتیک شارژ می شوند، جدا می کند، به جز موارد رطوبت شدید.

Dry air is one of the best isolation materials. A 12-in. air gap will isolate equipment charged with electrostatic voltage, except in cases of extreme humidity.

هوا بعضی از مزایای پلاستیکی را به عنوان یک جداساز برای سیستم الکترواستاتیک دارد

رنگ پاشنه پای میز پلاستیکی می تواند آن را هدایت کند. رطوبت در یک پوشش ضخیم گرد و غبار در یک لوله پلاستیکی می تواند آن را هدایت کند. ناسازگاری از هوا به عنوان یک جداساز کننده این است که آن یک سد به راحتی نفوذ می کند بین یک قسمت شارژ و یک قسمت زمینی به راحتی توسط پرسنل یا توسط شلنگ های شل یا سایر تجهیزات نفوذ می کند.

Air has some advantages over plastic as an isolator for an electrostatic system. A paint spill down a plastic table leg can make it conductive. Humidity in a thick coating of dust on a plastic pipe can make it conductive. The disadvantage of air as an isolator is that it is an easily penetrated barrier between a charged part and a grounded part — too easily penetrated by personnel or by loose hoses or other equipment.

متأسفانه تقریبا غیرممکن است که یک سیستم جداگانه طراحی شود که نمی خواهد تصادفی مبتنی بر، و یک سیستم که مبتنی بر خارج از آن، کمتر کارآمد است.

Unfortunately, it’s almost impossible to design an isolated system that won’t

accidentally ground out, and a system that grounds out is less efficient. In

در یک مورد، به عنوان مثال، 18 اینچ. طولانی، پایه توخالی پاکت پی وی سی یک مسیر مستقیم به زمین را فراهم می کند، زیرا بر روی یک طبقه بتنی و رطوبت از بتن ساخته شده است که درون پلکان هدایت می شود. این کوتاهی کوتاه مدت یک هفته کامل از عیب یابی برای پیدا کردن و تصحیح انجام شد.

one case, for example, an 18-in. long, hollow PVC table leg provided a direct path to ground because it was set on a concrete floor and humidity from the concrete made the inside of the leg conductive. That particular short took a full week of troubleshooting to find and correct.

علاوه بر عدم کارایی، سیستم های جدا شده می توانند خطرناک باشند زیرا می توانند انرژی الکتریکی بیش از حد را ذخیره کنند. تمام تجهیزاتی که با مواد پوشش داده شده الکتریکی خیس میشوند، انرژی الکتریکی را ذخیره می کنند، مانند خازن غول پیکر.

Besides being inefficient, isolated systems can be dangerous because they can store too much electrical energy. All the equipment that gets wetted with electrically charged coating material stores electrical energy, much like a giant capacitor.

در صورتی که سیستم خاموش شود، تمام انرژی ذخیره شده تخلیه می شود. اگر این سیستم به اندازه کافی بزرگ است و انرژی الکتریکی به اندازه کافی ذخیره می کند، یک اپراتور می تواند آن را با کوتاه کردن آن  به طور تصادفی با دست زدن به یک شلنگ یا اسپری کننده شارژ خراب کند.

All that stored energy gets discharged if the system gets shorted out.

If the system is big enough, and stores enough electrical energy, an operator can get injured by shorting it out accidentally by touching a charged hose or atomizer.

نمیتوان یک خط مشخص تعریف کرد که بیان کند:  "این سیستم کوچک ایمن است، و یک سیستم بزرگ خطرناک است. " تلاش برای تعریف یک شوک الکتریکی ایمن مانند تلاش برای تعیین یک ارتفاع ایمن است که از آن سقوط کند.

به عنوان مثال، شوک خود را فقط می تواند آزار دهنده باشد، اما قربانی می تواند به طوری از آن نا امید شده است که در نتیجه یک ضربه بر روی سر و یا آسیب در برخی از راه های دیگر.

It is impossible to draw a definite line that says, “A system this small is safe,

and a system that big is dangerous.” Trying to define a safe electrical shock is like trying to define a safe height from which to fall.

For example, a shock itself might only be annoying, but the victim might be so startled by it that it results in a bump on the head or an injury in some other way.

اگر چه یک سیستم ایمنی با توجه به ذخیره انرژی الکتریکی ممکن است در تناقض باشد، برخی از راهنمایی ها درباره اندازه سیستم احتمالا ناامن مفید خواهد بود.

متاسفانه، هیچ مقرراتی که به طور مستقیم برای سیستم های حمل و نقل الکتریکی قابل استفاده هستند در دسترس هستند.

Although a safe system, with regard to storage of electrical energy, may be a contradiction in terms, some guidance regarding the size of a “probably unsafe” system would be useful.

Unfortunately, no regulations directly applicable to electrically charged waterborne systems are available

با انجام بعضی مفروضات در مورد اطلاعات ناقص منتشر شده، برای مقادیر 70،000 / 100،000 ولت مورد استفاده برای الکترواستاتیک، با اضافه کردن مقادیر ولتاژ و ظرفیت Capacitance به معادله استاندارد برای ذخیره انرژی الکتریکی در یک خازن،

به شکل زیر می تواند گسترش یابد:

By making some assumptions about the meager data that is published,

extrapolating to the 70,000\100,000 V range used for electrostatics, and plugging the resulting voltage and capacitance values into the standard equation for storing electrical energy in a capacitor, the following can be developed:

Maximum\Energy = 3.5 Joules = CV2

where C=Capacitance (farads)

Rearranging: CMAX =7/V2

Maximum\Energy = 3.5 Joules = CV2

where C=Capacitance (farads)

Rearranging: CMAX =7/V2

جایی که ولتاژ حداکثر از پکیج قابل دسترس است

این معادله را می توان به عنوان یک شاخص از پتانسیل سیستم یک سیستم مشخص برای ایجاد یک خطر شوک جدی استفاده کرد. ظرفیت سیستم، همانطور که با یک پل خازنی یا یک اندازه خازن مناسب اندازه گیری می شود، باید کمتر باشد

از مقدار CMAX در صورت احتمال تماس تصادفی با انسانی وجود دارد می تواند منجر به شوک الکتریکی شود

به عنوان مثال، اگر یک سیستم رنگ آمیزی الکترواستاتیک 100،000-V دارای یک پیکو فاراد ظرفیت خازنی G700 باشد، برای حفاظت اپراتور باید برای قفل کردن و قفل کردن

where the voltage is the maximum available from the power pack.

This equation can be used as an indicator of the potential for a given isolated system to pose a serious shock hazard. The capacitance of the system, as measured with a capacitance bridge or a suitable capacitance meter, must be less

than the value of CMAX if there is a possibility of accidental human contact, which could result in an electrical shock.

 For example, if a 100,000-V electrostatic paint system has a capacitance G700 Pico farads, caging and interlocks should be considered for operator protection.

برای مقاصد مقابله، یک 55-gal تنها. درام و 200 فوت 3/8 اینچ. درونی شلنگ قطر، تمام 12 عدد در بالای زمین قرار دارد، میتواند بین 450 تا 900 عدد خازن داشته باشد.

این بدان معنی است که سیستم رنگ معمولی که دارای سخت افزار بسیار بیشتری است، تقریبا قطعا از حداکثر مقدار خازنی بالاتر می رود و می تواند سطوح بالقوه خطرناک انرژی الکتریکی را ذخیره کند.

For comparison purposes, a single 55-gal. drum and 200 ft of 3/8-in. inner

diameter hose, all set 12 in. above a ground, can have between 450 and 900 picofarads of capacitance.

 This means that a typical paint system, which has much more hardware, would almost certainly exceed the maximum capacitance value and could store potentially dangerous levels of electrical energy.

ذخیره انرژی الکتریکی را می توان با کاهش ولتاژ الکترواستاتیک کاهش داد. عبارت ولتاژ در معادله ذخیره انرژی در یک خازن به صورت مربع است.

  این به این معنی است که یک سیستم داده شده در 100000 V چهار برابر انرژی که در 50،000 وات است ذخیره خواهد کرد

The storage of electrical energy can be reduced by lowering the electrostatic voltage. The voltage term is squared in the equation for energy storage in a capacitor.

This means that a given system at 100,000 V will store four times the energy that it would at 50,000 V.

At the lower voltage, not only will the system be safer, but guns and cables will last much longer before breaking down electrically. Perhaps an even more compelling reason for lowering the voltage is to maximize TE.

اسلحه های چوبی یک مشکل خاص را در زمانی که یک سیستم کاربردی پوشش از مواد بر اساس حلال به آب منتقل می شود، از خود نشان می دهند.

The maximum TE for most waterborne coating materials occurs between 40,000 and 60,000 V.

By comparison, the maximum TE for a less conductive solvent-based material can be 90,000 V or more. Handguns present a special problem when a coating application system is converted from solvent-based materials to waterbornes.

An isolated electrostatic system for waterbornes can have multiple automatic atomizers or it can have a single handgun.

It cannot have both, nor can it have more than one handgun. National Fire Prevention Association (NFPA) regulations dictate that the electrostatic voltage to any handgun must turn off when the trigger is released.

این بدان معنی است که اگر تفنگ های دیگر در سیستم وجود داشته باشد، تفنگ با استفاده از الکترواستاتیک نمی تواند مورد استفاده قرار گیرد و بدون الکترواستاتیک امکان دستیابی به حداکثر TE

Since all the atomizers in a waterborne system are connected electrically by their fluid hoses, the voltage remains “on” to an idle handgun as long as it is “on” to any atomizer in the system.

This means that a handgun cannot be used with electrostatics if there are other atomizers in the system, and without electrostatics it is impossible to achieve the maximum TE

در عمل، این پتانسیل به ندرت به دست می آید، مگر اینکه سیستم کاربردی بسیار کوچک باشد زیرا انباشته شدن انبساط الکترواستاتیک دشوار است.

To summarize, completely isolated systems have the potential to allow the

maximum TE for a given application because they allow the coating material 200 to be directly charged with electrostatics.

 In practice, that potential is rarely achieved unless the application system is very small because it is difficult to keep the electrostatic charge isolated.

سیستم های کاملا جدا شده می توانند انرژی الکتریکی زیادی را ذخیره و خطرناک باشند.

برای جلوگیری از آسیب های اپراتور، چنین سیستمی نیاز به قفل شدن و مجهز به قفل های متصل شده برای جلوگیری از دسترسی در حالی که سیستم عامل است. متاسفانه این بدان معنی است که حتی نگهداری جزئی در تجهیزات غیر ممکن است در حالی که هر بخشی از سیستم در ولتاژ بالا عمل می کند زیرا تمام تجهیزات الکتریکی توسط شلنگ های مایع وصل شده است.این نیز همین دلیل است که تنها یک تفنگ دستی میتواند در یک سیستم کاملا جداگانه مجاز باشد

Fully isolated systems can store too much electrical energy and become dangerous.

To prevent operator injury, such systems need to be caged and equipped with interlocks to prevent access while the system is operating. Unfortunately, this means that even minor maintenance to the equipment is impossible while any part of the system is operating at high voltage because all the equipment is

electrically connected by the fluid hoses. This is also why only one handgun can be permitted in a completely isolated system.

باردار کردن غیر مستقیم

باردار کردن غیر مستقیم از بسیاری از مشکلات سیستم های کاملا جدا شده جلوگیری می کند، جز مساله هزینه.سیستم های باردار کننده غیر مستقیم ماده پوشش را بین نازل اتمایزر و قطعه باردار می کند، نه در اتمایزر.

Indirect Charging

Indirect charging avoids many of the problems of completely isolated systems, but at a price. Indirect charging systems charge the coating material between the nozzle of the atomizer and the part, rather than at the atomizer.

این کار با قرار دادن الکترود ولتاژ بالا در جریان هوا در نزدیکی نازل انجام می شود اما در تماس مستقیم نیست. ذرات ماده پوشش پس از ترک اتمایزر، باردار می شوند.

This is done by placing the high-voltage electrode in the air stream near the nozzle but not in direct contact. The coating material particles pick up a charge after they leave the

atomizer.

از آنجا که ولتاژ بالا هرگز به طور مستقیم با تجهیزات نرم افزاری ارتباط برقرار نمی کند، شارژ کردن شارژ کردن شلنگ های رنگی امکان پذیر نیست.

از سوی دیگر، هر گونه بار که  به طور تصادفی به سیستم کاری انتقال پیدا کند،  به محیط بی ضرر زمین انتقال پیدا میکند به زمین برسد زیرا سیستم از زمین جدا نیست. در واقع این سیستم ها می توانند و باید  به منظور جلوگیری از ذخیره انرژی الکتریکی به طور عمدی به زمین  پایه گذاری شوند

Because the high voltage never directly contacts the application equipment, there is no opportunity for the charge to drain away down paint hoses.

On the other hand, any charge inadvertently imparted to the application system drains away harmlessly to ground because the system is not isolated from ground.

 In fact these systems can, and should, be intentionally grounded to prevent storage of electrical energy.

با استفاده از تفنگ های دستی که  توسط شلنگ های الکتریکی  متصل نیستند، نیازی به محدود کردن تعداد سلاح در یک سیستم برنامه خاص نیست.

There is little capacitive storage of electrical energy in an indirect charged

electrostatic system so any electrical hazard is greatly reduced.

 This means that safety caging and interlocks can be less intrusive, or eliminated completely.

 With handguns no longer connected electrically by their hoses, there is no need to limit the number of handguns in a particular application system.

چندین دستگاه تولید کننده تجهیزات پوشش دهنده، اسپری های ویژه را برای شارژ غیر مستقیم طراحی می کنند

Several coating application equipment manufacturers offer atomizers specially designed for indirect charging.

بعضی از اسپری های معمولی نیز می توانند با دستگاه شارژ مستقیم غیرمستقیم، تبدیل و به آسانی تبدیل به آب  نسبتا ارزان باشند

These devices position the electrostatic electrode away from the coating material stream so that there is no direct electrical contact between the application equipment and components charged with high voltage.

Some conventional atomizers can also be retrofit with indirect charging apparatus, making the conversion to waterbornes easy and relatively inexpensive.

The downside of indirect charging is lower than optimum TE. Indirect charging does improve TE over comparable non-electrostatic systems. Unfortunately, tests prove that the TE with indirect charging is less than the TE that can be achieved by direct charging in any given application — that means using the same applicators,

coating material, part shape, etc.

تفاوت می تواند قابل توجه باشد، تا 40٪ بهبود در TE در موارد شدید. حتی بهترین سیستم های باردار غیر مستقیم  به ندرت به TEs در 10 درصد از آنچه برای یک برنامه کاربردی در شرایط استفاده از باردار کردن مستقیم برای الکترواستاتیک قابل دستیابی است می رسد.

The difference can be considerable, up to 40% improvement in TE in extreme

cases. Even the best indirect charged systems rarely achieve TEs within 10 percentage points of what is possible for the same application but using direct charging for the electrostatics.

To maximize TE, the coating material should be directly charged with electrostatic voltage, but to minimize shock hazards and operational problems, the size of the charged parts of the system should be minimized. This can be achieved by using a voltage block at each atomizer. Each atomizer then becomes a miniisolated

system with no electrical connection to any other atomizer in the system.

بلوک های ولتاژ

بلوک های ولتاژ دستگاه هایی هستند که به مواد پوشش می دهند تا از طریق آن عبور کنند

اما برای جلوگیری از انفجار ولتاژ از راه دیگر.

Voltage Blocks

Voltage blocks are devices that allow coating material to pass through to the

atomizer but prevent voltage from leaking back the other way.

They allow coating material to flow from the grounded pumps or kitchen to charged atomizers.

This means that the hardware in the pump house and distribution system can be virtually the same as for a conventional solvent-based system, or for an indirect charged waterborne system.

از آنجا که مزیت اصلی فن آوری ولتاژ بلوک این است که آن را محدود کردن مقدار سخت افزار در ولتاژ بالا، مهم است که این دستگاه ها را به عنوان نزدیک به atomizer نصب کنید که ممکن است

Since the primary advantage of voltage block technology is that it limits the amount of hardware at high voltage, it is important to install these devices as close to the atomizer as possible.

The connecting hoses between the voltage block and the atomizer are at high voltage, so keeping them short minimizes both the capacitance and the opportunity for accidental grounding.

 A voltage block for one atomizer is compact, requiring about as much space as a small electrical control box, so it can be mounted inside the spray or ventilation booth close to the atomizer.

The mini-isolated systems created by voltage blocks do not have the problems found in large isolated systems because less hardware is charged with electrical energy. Capacitance is greatly reduced, making the system inherently safer.

 Safer systems mean easier access to the inside of the spray booths. Often a simple guard rail and warning sign can replace elaborate caging and interlocks.

ولتاژ

Voltage

leakage problems are minimized, since only the atomizer and a short hose are

charged, making it easy to keep the TEs up to a high level.

By isolating atomizers from each other, mini-isolated systems have some unexpected advantages.

First, the NFPA limitation concerning handguns no longer applies.

Each handgun is independently isolated from every other handgun so the voltage to idled guns can be turned “off.”

از آنجایی که ماده پوشش آب در آب باعث تولید برق می شود، اما می توان آن را به طور مستقیم در واحد ولتاژ متصل کرد و کابل را به تفنگ می توان حذف کرد.

با استفاده از کابل، اسلحه احساس سبک تر می شود و بسته نرم افزاری شل سبک تر می شود

In fact, spraying waterbornes with a handgun and voltage block can be easier than spraying the old solvent-based material with the handgun.

 Solvent-based material is charged at the gun barrel so a high-voltage cable to the gun is required.

Since waterborne coating material conducts electricity, however, it can be directly charged at the voltage block and the cable to the gun can be eliminated.

 With the cable gone, the gun feels lighter and the hose bundle flexes more easily.

این به این علت است که کابلهای ولتاژ بالا زمانی طول می کشد که آنها با حرکت اسلحه یا ربات به بالا و پایین نمی روند.

Even automatic atomizers, such as rotaries or disks, require less maintenance if the coating material is charged at the voltage block rather than at the atomizer, as it was when spraying solvent-based material.

This is because the high-voltage cables last longer when they don’t get flexed over and over by the motion of the gun mover or robot.

دومین مزیت غیرمنتظره ساخت هر نوع اسپری کننده به یک سیستم مینی جدا شده این است که هر اسپری کننده می تواند با ولتاژ مختلف یا ولتاژ صفر به صورت دلخواه عمل کند

به عنوان مثال، تجربه در کارخانه ممکن است نشان دهد که اتمیزر چرخشی در یک خط رنگی بهترین در 60،000 V است، اما دست زدن به آنها در 45،000 V بهتر عمل می کند. با استفاده از بلوک های ولتاژ، تفنگ ساچمه ای و اسپری کننده های چرخشی می توانند در ولتاژ های مختلف اجرا شوند، اما همه می توانند از یک سیستم توزیع رنگ معمول

A second unexpected advantage of making each atomizer into a mini-isolated system is that every atomizer can operate at a different voltage, or at zero voltage, as desired.

For example, in-plant experience might show that the rotary atomizers in a paint line run best at 60,000 V, but the handguns perform better at 45,000 V. With voltage blocks, the handguns and the rotary atomizers can run at different voltages, yet all can be supplied from a common paint distribution system.

سهولت دسترسی به تجهیزات کاربردی تولید قابل مقایسه است بین یک سیستم آبگیر با ولتاژ متوقف شده و سیستم مواد پوشش دهنده مبتنی بر حلال جایگزین می شود.

Finally, in an application system for waterbornes and using voltage blocks,

any atomizer in the system can be shut down and repaired or changed out, even though the other atomizers are operating at high voltage. The ease of access to production application equipment is comparable between a voltage-blocked waterborne system and the solvent-based coating material system it replaces.

نتیجه گیری

یک هدف اغلب ناگفته در هنگام تبدیل یک سیستم کاربردی پوشش به آب به منظور جلوگیری از "همانطور که اکنون انجام می شود" برای به حداقل رساندن ممکن است، به خصوص اگر سیستم موجود دارای تجهیزات مناسب و خوب عمل کند

این هدف از دسترس نیست، زیرا فرآیند موجود و بسیاری از تجهیزات موجود، اغلب می تواند برای آب در نظر گرفته شود.

CONCLUSION

An often-unstated goal when converting a coating application system to waterbornes is to disrupt “the way it’s done now” as little as possible, particularly if the existing system has good equipment and is performing well.

 That goal is not out of reach because the existing process, and much of the existing equipment, can often be used for waterbornes.

تجهیزات و سیستم توزیع باقی مانده را می توان مجددا استفاده کرد، مگر اینکه از موادی ساخته شده باشند که در داخل آب خورده می شوند یا تحت تاثیر قرار گرفتن در معرض آنها قرار گیرد.

Usually only the atomizers will need to be modified for waterbornes, or replaced with atomizers specifically designed to handle waterborne materials.

The remaining equipment and distribution system can be reused unless made of materials that will corrode in waterbornes or be damaged by exposure to them.

Well-engineered conversions from solvent-based coating materials to waterbornes result in the highest possible operating efficiency at low cost and with maximum operator safety.

The operating cost, in terms of TE, should be about the same as that of a good solvent-based paint system.

To get high TE, electrostatics must operate at peak efficiency. This means directly charging the material with electrostatic voltage, but limiting the hardware that gets charged.

دستگاه های مسدود کننده ولتاژ، ولتاژ الکترواستاتیک بالا را فقط برای دستگاه های اسپری و شلنگ به دستگاه اسپری متصل می کنند.

Voltage-blocking devices confine high electrostatic voltage to only the atomizer and hoses to the atomizer. This means that the rest of the coating material application system can be the same or similar to the system before the conversion is made

الکترواستاتیک همچنان با راندمان بالا کار خواهد کرد، زیرا ماده پوشش را می توان به طور مستقیم باردار کرد، بنابراین TE قبل و بعد از تبدیل قابل مقایسه خواهد بود.

The electrostatics will still operate at high efficiency because the coating material can be directly charged so the TE will be comparable before and

after conversion.

Because system capacitance, or the capacity to store electrical energy, can be controlled to “safe”’ levels, safety issues with the converted systems are not prohibitive

به عبارت دیگر، یک سیستم محلول در آب با ولتاژ متوقف شده تا حد امکان به سیستم مواد مبتنی بر حلال در حدی مشابهت دارد که می تواند با مواد پوشش داده شده که برق را هدایت کند جایگزین شود.

In other words, a voltage-blocked waterborne system is as close as possible to the solvent-based material system it replaces with a coating material that conducts electricity.

به طور خلاصه، در اینجا نحوه تبدیل یک سیستم کاربردی از مواد پوشش دهنده مبتنی بر حلال به آبرسانی در اینجا است

To summarize, here is how to convert an application system from solvent-based coating materials to waterbornes:

(1) Reuse the existing process and hardware if it is up to date and performing well for the existing solvent-based system. Change components where materials are not compatible with waterbornes.

2. هر دستگاه اتمایزر را از طریق  نصب یک بلوک ولتاژ در شیلنگ مواد پوشش، تا  نزدیک ترین بخش ممکن به اتمایزر به یک سیستم مینی جدا شده تبدیل کنید.

(2) Turn each atomizer into a mini-isolated system by installing a voltage block in the coating material hose, as close to the atomizer as possible. Directly charge the material for maximum TE.

(4) از این مزیت که محلول در آبها جریان الکتریسیته را عبور می دهد استفاده کنید.کابل های الکترواستاتیک را از اتمایزرها جدا کنید  و در بلوک ولتاژ باردار کنید. کابلها طول عمر بیشتر داشته و اسلحه ها راحت تر حرکت خواهند کرد.

(3) Lower the voltage to maximize TE, extend equipment life, and reduce shock hazard.

 (4) Take advantage of the fact that waterbornes conduct electricity. Remove the electrostatic cables from the atomizers and charge at the voltage blocks. Cables will last longer and the guns will move easier.