How to Manual

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Fabricating Raised Graphic & ADA Compliant Signage using Photopolymer

What You Will Need…

Manufacturing the highest quality ADA compliant and raised graphic signs with NovAcryl and other Nova photopolymers requires a few basic shop elements. The following checklist will help determine the capital investment needed to begin fabricating photopolymer signs in-house.

  1. Means to generate artwork and Film Negative with Grade II Braille
  2. Shear (Nova Polymers) or Saw for cutting photopolymer materials before or after processing. http://www.novapolymers.com/products/equipment/15
  3. Orbital X Photopolymer Processing Unit from Nova Polymers http://www.novapolymers.com/products/equipment/photopolymer-proccessors
  4. Shop equipment for fabricating and finishing.
  5. Paint Booth for applying automotive grade acrylic polyurethane paints.
  6. Hot Stamp unit (Nova Polymers) or silk screen capabilities for finishing. http://www.novapolymers.com/products/equipment/14

Generating Proper Film Negatives

Since photopolymer graphics are created through photographic exposure, generating consistent film negatives is perhaps the most critical first step in manufacturing photopolymer signage. Why? Because, in many cases, improperly processed photopolymer becomes costly waste. Successful processing is dependent almost entirely on the initial exposure. There are THREE general types of film negatives; Film, rubylith and velum. There are also several ways to generate each general type and each can deliver acceptable results. Photopolymer processing is customized around the type of processing equipment and film output you use. Customizing involves Braille diameter and exposure. The primary consideration when choosing a film type should always be the potential effect on the photopolymer’s durability. No film source, no matter how economical, is worth the cost of reduced durability and raw material waste. The following information describes the most common methods of producing film and what you need to be aware of when translating design into film. You need to alter Braille Diameter in your software package. This adjustment is needed to create the rounded effect being emphasized in the new ANSI standards.

Braille Translation Software

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Grade II Braille translation software is available from a variety of sources. DUXBURY SYSTEMS is perhaps the most popular. Their technical support team can guide you through the necessary adjustments. With the variety of film types available, you need to adjust Braille diameter to achieve optimum results. With the emphasis on "rounded or domed" Braille, customizing diameter is almost mandatory. Braille software generally starts with the diameter measurement of a dot’s base. When translated to film without adjustment, the .060" base diameter becomes the surface diameter after processing. The readable surface diameter of Raster Braille (domed) is between .028" and .042". Modifying the surface diameter of photopolymer Braille to between .035" and .040" will produce a similar readable surface (rounded).

Film Negative

Film negatives can be produced through a variety of methods. The most commonly used are listed below.

  • Processed Film direct to Linotronic Similar processing to stat camera method without the camera. The film is imaged through a digital unit and transferred by canister to a processor.
  • Ink Jet Film A relatively new and effective method of generating wide format film using dye or pigment based inks
  • Thermal Image Film The use of thermal imaging media for producing photopolymer film has grown over the past few years.
  • Oyo Thermal Film Imager is a popular printer within the sign industry. It will produce films up to 54" wide by a variety of lengths.

Rubylith (Amberlith) Negative

"Ruby" is easily cut on your plotter and has almost unlimited photo-latitude.

Velum Negative

Producing film with laser printed velum paper is fast and relatively inexpensive but we do not recommend it simply because of overall poor quality and raw material waste when using it.

Processing Photopolymer Sheets

Novapress 70 After you have produced a film negative, the next step in sign fabrication is to process the photopolymer sheet. It is a very simple process requiring only about 30 minutes using a Novapress 70 processing unit. The Novapress 70 is a complete four stage unit and can process up to 70 flats of photopolymer each day.

Step One: Exposing the Photopolymer

  1. Place the photopolymer sheet on the exposure frame, FACE UP.
  2. TURN ON VACUUM and peel away clear protective cover film.
  3. Place your artwork EMULSION DOWN on the photopolymer sheet.
  4. Roll the VINYL COVER SHEET over both.
  5. Achieve vacuum pressure.
  6. Gently rub out any air pockets with hand or cloth covered block.
  7. Push exposure tray in and UV light will expose the photopolymer.

Step Two: Washout (Etch)

  1. After exposure, remove photopolymer and negative.
  2. Mount photopolymer to adhesive mat on the lid of washout tank.
  3. Set washout timer to recommended duration (5:00-6:00 min)
  4. Lower the lid so photopolymer is face down in water and in contact with brush action
  5. Washout unexposed photopolymer

Step Three: Dry

  1. After washout is complete, remove the photopolymer sheet.
  2. Rinse the sheet throughly with fresh, cool water. Garder hose type pressure or power washing is acceptable.
  3. Use compressed air to remove all remaining water from the sheet prior to dry cycle.
  4. Once the sheet is free of water, place it face up in the dryer.
  5. Dry as factory specified

Step Four: Post Exposure

  1. Place dried photopolymer sheet in the post exposure section of machine. If your processor is not equipped with a separate post exposure section, You will need to place the material on top of the vinyl cover sheet of your main exposure tray. No vacuum is required.
  2. Push the tray back in and post expose for 2:00.

Fabricating

Preparing processed photopolymer sheets for finishing After the photopolymer material has been fully processed, separate the parts as needed leaving no more than 1/4" over. (unless you are planning to put full sheets on a router table) There are several different ways to machine your processed photopolymer material to finished size. We will use NovAcryl for examples since it is a solid backed photopolymer sign material. All other types, such as aluminum or polyester will require lamination to a base prior to beginning final fabrication.

Shear Cutting and Radius Corners

NovAcryl is the one material that allows you to apply a finished edge with a shear. The time needed to send a "shear cut"NovAcryl project to paint versus tooling a phenolic or aluminum backed material is reduced by as much as 70%.

Routing to finished size

Routing with a template, secured by vacuum or double faced tape is the most common method for tooling custom shapes. Use the registration marks or outside border originally printed in your film to help line up your template.

Nova suggest using a BOSCH 1/2" Laminate Flush Treim Router Bit. Two flutes, carbide tipped with ball bearing. (85266M)

Painting Photopolymer Signs

Use automotive grade ACRYLIC POLYURETHANE for all top coating. Specifications for Nova materials have been written by MATTHEWS. Details found here: http://www.novapolymers.com/technical-support/painting

Applying Color To Raised Elements

The primary methods used to apply color to painted and unpainted raised text and characters are silk screening or hot stamping. Internal building directory using surface painted YA-125 Aluminum Photopolymer,acrylic polyurethane and hot stamped visual elements.

Silk Screen

Silk screening is the most widely used method for tipping. A skilled silk screen artist will adapt to any number of variations of the following method.

  1. Create a jig to hold location of signs to be printed.
  2. Block out area around the raised elements to be printed. (note: Block out the area of the one sign that has the largest copy area to be printed)
  3. Use a hard durometer squeegee (80 durometer)
  4. Use rails to keep squeegee from dipping down to the face or shoulder. Rails should be .040 thick and can be attached to the blocked out underside of the screen.
  5. Flood the screen with ink. Nazdar S2 series. Use a 305 meesh screen.
  6. Drop the screen and draw the squeegee over the raised elements (this is where individual technique will play a vital role in the end quality)
  7. Lift the screen, remove the part, and clear the screen prior to repeating the process. (Note: Place a sized piece of acrylic covered with newsprint into the jig. The acrylic should be 1/8" thicker than the sign.)

Hot Stamping

The hot stamping method has become very popular over the years, especially in the wholesale market. It is fast, dry and clean.

  1. Cut the foil to a size that covers the raised elements. It is not necessary to be exact, just don’t be short.
  2. Turn on the heating elements and set temperature for around 180c. Preheat for 15:00 minutes.
  3. Place the sign on the work table of the hot stamp unit.
  4. Place the foil face down over the raised copy (the dull side of the foil is the face, you will see the true color through the back of the film carrier).
  5. Push the work table back into the machine directly under the heated silicone pad.
  6. Bring the heated silicone pad down onto the foil and sign with minimal pressure for less than a second, or until just after pressure is applied. (Note: Required pressure will increase with larger copy areas)
  7. The thermal activated pigment is transferred melts onto the sign face and the process is complete.

Epson 1280 Printer Setting for InkStar Film

Click here for a detailed guide on how to set the Epson 1280 printer for Inkstar film

Novacryl Fabricating and Finishing Techniques

Click here to download the guide to Novacryl Fabricating and Finishing Techniques