Emulsion/Capillary Film

    Many shops ask about the differences in products, and particularly emulsion vs. capillary film.  Those differences are described briefly below which you can find by clicking on Explanation. 

    Products:                      Capillary Film                Liquid Emulsion

Capillary Film


CDF=diazo      CDF/LX=dual cure      CDF-QT=photopolymer
Other thicknesses, sizes, and chemistries are available, plus custom sheet sizes

Liquid Emulsion
 

To Order, fax 518-798-3172 or email to   roger  @  rjennings.com   or call 800-500-2279

Name ___________________________  Company ________________________________
Street ___________________________  City __________________ State _____ Zip _____
PH      _____________________  Fx:  ___________________  email __________________
Credit Card __________________________________  Exp __________
Coupon #'s  _____________________________ It is safer to fax or phone credit card #

Back to Products               Front Page    

Explanation:    There are 3 basic chemistries to select from each of which is available as liquid emulsion, or capillary film.  Capillary film is liquid that has been coated to a plastic sheet at one of a variety of precise thicknesses, and dried.

    The 1st emulsion developed was the diazo chemistry.  Here a powder is added to the emulsion to activate it, and then the mix has a short pot life.  There are numerous products available in this class with different properties.  This emulsion is used with plastisol inks printed on apparel.

    The 2nd emulsion developed was dual cure.  This is a chemistry of diazo with an acrylic added so that the emulsion can be used with water based and solvent based inks.  Such inks would attack diazo alone.  Water based inks are commonly used with towels and apparel which will be dry cleaned or where a very soft hand is desired.  Solvent based inks are used for many non-apparel items like coroplast. 

    The 3rd chemistry is photopolymer.  Designed in more recent years, these emulsions work with plastisol inks.  Their principal benefit is very fast exposure times.  They are also one part emulsions that do not need to be refrigerated like a mixed diazo.  They expose in about 1/4 of the time required for a diazo or dual cure.  Quick Film is a photopolymer that exposes 60% faster than CDF-QT50, and is exclusively sold by R Jennings Mfg.

    The exposure time required will vary depending on chemistry, thickness of coating, and manufacturer.  The differences are huge.  For example, Quick Film 50 microns made for us by Ulano completely exposes in 21 seconds on our NuArc 40-1K exposure unit, but another photopolymer also 50 microns made by a major name competitor does not expose satisfactorily even after 3 minutes and 40 seconds, and the Quick Film is less expensive.  Testing or getting advice from a reliable source can save lots of time and money.

    Capillary films were developed in more recent years and offer unique advantages compared to liquid emulsion.  First, capillary film is applied to a wet screen so that time is not lost waiting for a screen to dry before a liquid emulsion is applied.  Wet screens don't trap dust on mesh that later becomes the source of pin holes when liquid emulsion is used.  The coating thickness is marked on the package, and an exposure calculator can be used to measure the precise amount of light necessary for exposure.  That is very important for so many shops that use computers to produce image positives, and those positives are not dense black.  Once that exposure time has been measured and recorded, the same time is used over and over until the bulb wears and a screen appears a little under exposed.  Then the recorded time should be extended by 10% to compensate for the declining bulb.  Capillary produces a predictable and controllable thickness to the ink deposit which is important for opacity, hand, and ability to create new forms of graphics.  Edge definition and image resolution is clearly superior, and screens are easier to reclaim.  For shops using "stretch and glue" frames (wood and welded aluminum), the stencil coating and therefore ink deposit will be uniform rather than a thicker emulsion in the center of the screen which produces heavier ink deposits rather than the image specified by the artist.

    People have two objections to capillary film.  First, new shops sometimes have problems applying film satisfactorily.  We have a goof-proof method.  Second, cost.  Per square inch, capillary costs more than liquid to purchase.  The sophisticated screen printer realizes that there are costs in addition to the material, and these other costs are much greater than the material cost.  When considering total cost, capillary film is less expensive.  These other costs include the cost of the person's time to prepare a screen for printing and reclaim it later, and the overhead of the business that is absorbed with each hour of labor.  In most businesses, overhead runs 3-4 times the cost of direct labor.  What is the cost of one pin hole from using liquid emulsion in terms of garments that could have been printed while the pin hole is being fixed and the costs and problems of removing the unwanted ink deposit?  Our customers who understand the many differences, which are too many to list here, use capillary exclusively.

    We have tested all the brands, and have found Ulano's products to be clearly superior and most cost effective.  Thus, we only sell and use in our own printing operations Ulano products.

Back to Products       Front Page