DYM Dymax logo
UV Curable
Dome and Decorative Coatings
  • UV coatings cure in seconds
  • Greater productivity
  • JIT process and delivery
  • Less inventory
  • Eliminate hundreds of racks
  • Eliminate ovens
  • Regain floor space
  • Eliminate mercury and isocyanates from the workplace

Advanced Coating Technology for Faster, Better Processing
Since 1980, DYMAX has pioneered adhesive curing technologies which dramatically reduce assembly costs and increase the profit potential of manufacturing processes. Chemistries which slash curing times from days to minutes and hours to seconds, provide productivity increases or 90% or more for automotive, medical electronic and general industrial assembly operations.


Feature Benefits
Faster production Faster customer response
Reduced order to shipment time
Greater productivity
Cure on demand Instant light cure “locks out” airborne contamination
Cure occurs when and where you want it
One part resin Consistent viscosity means fewer rejects; less scrap
Less chance for air entrapment; improved yield
Reduced purge and resin waste disposal
Eliminates the need for metering & mixing equipment
Small footprint Frees factory space for more production
Less labour Reduced Costs
No mercury
No isocyanates
Fewer health and safety issues
Fewer disposal issues and costs

Considerations for Selecting a Coating

1) Viscosity
How thick a coating is necessary? Protective decorative coatings are clear and usually thin. Dome coatings have curved domes, which optically magnify and enhance the appearance of a label. Higher viscosity, thicker resins generally produce taller domes.

2) Substrate Flexibility
Flexible substrates, like thin polyester labels, paper, or soft plastics, may require careful selection of coating and enhanced curing equipment. Flexible substrates may bow or warp when thick coatings cure. Soft coatings shrink less and are designed to reduce or eliminate warpage during cure. Rigid substrates don't bend when stressed; so, they can be coated with all of the products.

3) Substrate Adhesion
Individual formulations may have excellent adhesion to some inks (or substrates) and little adhesion to others. The right coating should have good adhesion to the substrate. Adhesion should be tested after product lifetime testing, as well as after cure. Inks and substrates from second source suppliers may improve or worsen adhesion. Some plastics require surface treatment to enhance adhesion. DYMAX 4-20586 responds well to surface treatment.

4) Hardness
Both soft and hard coatings can be scratch resistant. Hard coatings resist scratching because of their hardness. Soft coatings resist scratching because they momentarily dent and then spring back when the scratching object is withdrawn. Hard coatings are measured on the D-hardness scale. Soft coatings are measured on the A-hardness scale. On both scales, higher numbers imply harder coatings.

5) Environmental Durability
Coatings should be lifetime tested on your product. Some properties, like UV weatherability, provide a relative guideline to distinguish endurance of clarity and durability among the available products offered.

Industrial Dome and Decorative Coatings Selector Guide

Product Applications Characteristics Hardness Durometer (1) Viscosity
(cP)
Relative Weatherability
Dome Coatings
 4-20564
82Kb
Small Decals
(Up to .25" × .5")
Hard scratch resistant surface; resists yellowing D-75 6,000 Limited outdoor (3)
 4-20435
81Kb
Pen tops, small labels
(to .25" × .5")
Hard scratch resistant surface; resists yellowing D-75 3,400 Excellent Indoor
 4-20577
88Kb
Medium Decals
(Up to 1" × 3")
Surface springs back from dents; difficult to scratch; resist yellowing A-70 1,500 Limited outdoor (3)
 4-20429
127Kb
Large Decals
(Up to 1" × 8")
Surface springs back from dents; resists yellowing A-70 1,500 Good indoor
 4-20586
17Kb
Plastic and metal name badges Cures with lowest intensity lamp D-60 1,200 Indoor only
 4-20508
83Kb
Plastic and metal name badges Hard scratch resistant surface; resists yellowing D-80 800 Excellent indoor
 4-20630
88Kb
Medium decals (up to 1" × 2") Surface springs back from dents; difficult to scratch; resists yellowing A-75 800 Limited outdoor (3)
 4-20645
79Kb
Small decals and objects UV curable "rubber feet"; clear anti-skid coating A-75 600 Good indoor
Decorative Coatings
 4-20624 (2)
(68Kb)
Matte finish, low gloss, low viscosity Low gloss is a typical of UV coatings D-85 800 Good indoor
 4-20638
High gloss High hard gloss coating D-80 100 Limited outdoor (3)

Dome Coating Applications


DYMAX 4-20564 is used to
continuously coat logo decals

DYMAX 4-20508 with a high
gloss finish is used to decoratively
coat a key chain

DYMAX 4-20577 is used to
coat a medium size decal

DYMAX 4-20435 resin is
used to seal a label in a pen cap

UV Lamp Selection is Critical to a Successful Process
The UV curing lamp used affects appearance and feel of a coating. Although the highest power lamp will cure the coating fastest and produce the smoothest, slickest surface, it may also warp, yellow or melt the object being coated (and it will cost the most). It is always best to test an application with several light sources. Lifetime tests sometimes favor one lamp system over another.

DYMAX Has What You Need for Safe UV Processing and Process Control
DYMAX equipment is shielded so that operators and others are not exposed to UV light. DYMAX also supplies protective goggles and face shields. The DYMAX ACCU-CAL™ 30 radiometer, an essential tool for measurement and control of the light curing process, is also available.

Match a DYMAX Curing System to the coatings and application for the best process, every time!

Applications Recommended Lamps Considerations
Small decals and pen tops on rigid substrates 5000-PC or conveyor with Fusion D-bulb  
Large decals on rigid substrates 5000-PC or 2000-PC followed by 5000-EC Second option manages heat
Small decals on flexible substrates 2000-PC  
Medium and large decals on flexible substrates 2000-PC or black light followed by brief exposure to shortwave light or a high power lamp Second option manages heat and possible label warpage


Shielded Light Curing Chambers

Conveyorised Curing Systems

Process Tips for Successful Coating
Avoid resin running over the edge of the label or object

1) Resin is deposited at the center of the label or object and flows towards the edges. Sharp edges tend to repel overflow. Irregular edges encourage overflow. Thick label stock tends to maintain its edge and minimise overflow.
2) Label backing can minimise or encourage overflow. If the backing material "wets" more readily than the label surface, it tends to draw the coating over. Using a backing that repels the resin encourages it to remain on the label.
3) Use an X-Y dispenser to dispense a pattern instead o a single drop on noncircular objects. Pattern dispensing lets the resin flow to all the edges at the same time rather than all running to one edge where it can flow over before reaching the remaining edges.
4) Level the dispenser, transfer and curing stations.

Avoid air bubbles in the coating
1) Purchase products in air free packages (syringes or cartridges).
2) Dispense directly from the shipping container. If resin must be transferred from one container to another, then transfer the container at the end of the last shift.
3) Use low pressure dispensing. Since pressure drops can pull air into the dispensing line, dispense with the lowest pressure possible.
4) Use the shortest possible lines between the container and the dispensing needle.
5) Pass the uncured (liquid) coating underneath a natural gas flame to burst surface bubbles.
6) Process by continuous dispensing and purge tip when restarting line. Whenever fluid flow stops completely, the resin may retract. When resin retracks it can pull air into the line or dispensing tip. The air can create bubbles before it is purged from the line.

Eliminate warpage during cure
1) Some thermoplastics curl or warp when hot. Use a thermoplastic with a higher melting point or reinforcement to solve this problem. Using a thicker substrate may also eliminate warpage.
2) To eliminate curl when doming on thin polyester labels try precuring with a "black" light. The "black" light should have a maximum intensity at 365 nm. Regular purple colored bulbs or germicidal bulbs will not work. The precuring polymerises the coating below the coating's surface. A second lamp is then used to cure the surface to a scratch resistant state. As the label gets larger, softer resins are necessary to prevent warpage.
3) Use of thicker polyester stock to stiffer backing sheets minimizes curl of domed decals.


Other Information
A sales brochure for DYMAX Dome & Decorative Coatings is available; click here ( 174Kb).
Additional printed catalogue or brochure available
Obtain more information, samples or literature
Contact details and how to order
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December 2002
Version 1.0

Statements, technical information and recommendations contained herein are based on tests we believe to be reliable but they are not to be construed in any manner as warrantees expressed or implied. The user shall determine the suitability of the product for his intended use and the user assumes all risk and liability whatsoever in connection therewith.