3M Production Standards Manual for
the Manufacture of
Permanent Prismatic Road Signs
with
3
3MTM Diamond Grade DG 4090 series
3MTM High Intensity Prismatic HIP3930 series
3MTM Engineer Grade Prismatic EGP 3430 series
3M Production Standards Manual for Permanent Prismatic Signs
Table of contents:
1. Introduction
2
2. Signshop conditions
5
3. Substrate preparation
6
3.1. Aluminium
7
3.2. Galvanized steel
8
4. Permanent Sign making
10
4.1. Sheeting storage and handling
12
4.2. Sheeting preparation
12
4.2.1. Planning sheeting use
12
4.2.2. Cutting sheeting
15
4.3 Screen printing
17
4.4 Digital Printing
4.5 Application
19
4.5.1. Manufacturing of smaller signs
20
4.5.2. Manufacturing of larger signs
22
5. Packing and storage of finished traffic signs
31
6. Trouble shooting guide:
32
6.1. Handling prismatic sheeting
32
6.2. Screen printing on prismatic sheeting
34
6.3 Digital Printing
41
6.4. Handling finished signs and sign faces
42
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3M Production Standards Manual for Permanent Prismatic Signs
1. Introduction
The 3M prismatic sheeting range provides an excellent, robust product in
each of the three recognised levels of retro-reflective performance. These
materials are 3M Engineer Grade Prismatic (EGP) Series 3430, 3M High
Intensity Grade Prismatic (HIP) Series 3930 and 3M Diamond Grade (DG3)
Series 4090 and 4080 Fluorescent.
These 3M prismatic sheetings may be used to make road traffic signs
which are in compliance with BS EN 12899-1:2007. In accordance with that
standard, these sheetings have European Technical Approvals and are
certified to the following retro-reflective performance levels:
EGP is certified as Class RA1 retroreflective material
HIP is certified as Class R2 retroreflective material
DG3 is certified as Class 3A and 3B retroreflective material
Traffic signs made with these materials provide excellent night and day
performance in their respective classes. When compared with materials
made with glass beads these 3M prismatic materials:
♦ are whiter and produce bright, clear colours using inks and overlays;
♦ are physically strong to better withstand handling during
manufacturing and installation;
♦ have excellent durability in use and excellent retention of colour and
reflectivity
This manual provides manufacturing guidelines for sign producers making
permanent signs using 3M prismatic films. It also contains information on
common problems encountered when producing reflective signs and how
to avoid them. It is important to note that the performance of retro-reflective
materials can be negatively affected if 3M recommendations on the
manufacturing, storage, handling and maintenance of signs and 3M
signmaking components are not followed. 3M warrants the performance of
its products but does not control the manufacture of signs using them. This
manual is intended to assist signmakers by providing these
recommendations in a concise format. 3M have a comprehensive set of
information bulletins for sign manufacture from which this manual draws.
Consultation of these bulletins is also recommended.
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3M Production Standards Manual for Permanent Prismatic Signs
The materials:
Figure 1 contains photographs of the three 3M prismatic materials. All three
have a diamond shaped seal pattern but can be easily identified from one
another by visible features. Both EGP and HIP have parallel stripe pattern
within the sheeting in the unwind direction of the roll. Functionally, the
stripes enable consistent performance whether the sheeting is used
horizontal or vertically on a sign. EGP has a matte appearance while HIP is
glossy. In comparison, DG3 has a uniform diamond network without stripes
and a glossy top surface.
All three materials have tooling lines and the memorable diamond seal
pattern which are visible on close inspection but do not affect day or night
appearance or performance of the finished signs.
DG3 reflective sheeting is available in white, yellow, red, blue, green,
fluorescent yellow, fluorescent yellow-green and fluorescent orange
colours. It is not available in grey, brown or green 2 (otherwise called
Worboys Green).
HIP reflective sheeting is available in white, yellow, orange, red, blue and
green colours. It is not available in grey, brown or green 2 (otherwise
called Worboys Green).
EGP is available in white, yellow, red, blue and green colour. It is not
available in grey, brown or green 2 (otherwise called Worboys Green).
3M has matched system of signmaking components with which signmakers
can produce warranted signfaces. These include 3M inks for screen and
digital printing, 3M coloured overlay films, 3M Scotchcal non-reflective films
and 3M clear overlay films which may be used to provide various added
functionality (graffiti resistance, dew resistance, etc).
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3M Production Standards Manual for Permanent Prismatic Signs
unwinding direction
3M EGP
3M HIP
3M DG3
Figure 1 – images of 3M prismatic materials
.
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3M Production Standards Manual for Permanent Prismatic Signs
2. Signshop conditions
As with most retroreflective materials, prismatic sheetings have
requirements or limits for the conditions in which the signmaking process
are done. Typically 3M prismatic materials are less sensitive to production
conditions than sheeting made with glass beads.
♦ Temperature requirements:
Prismatic sheetings are relatively stable over a wide range of
temperature. However some manufacturing processes become
unworkable in temperatures much outside the optimum range of 180 and
220 C . Within that optimum range any of the manufacturing processes
may be done. This temperature range also represents a comfortable
working temperature for those doing the work.
Screen printing becomes impractical outside a range of 160 to 280 C.
Lower temperatures will cause changes in the ink viscosity which can
make consistent screen printing almost impossible. Screen printing at
temperatures of 100C or lower can cause the sheeting to crack because
the ink’s solvents do not evaporate quickly enough. At temperatures
higher than 280 C inks dry faster and may clog up screens.
It is possible to conduct processes other than screen printing at
temperatures outside the optimum range. 3M prismatic sheeting can
withstand high and low temperatures very well and applications at
temperatures up to 300 C have been done successfully. However,
temperature may alter the flexibility of sheetings (stiffer at low
temperatures) and the “grabbiness” of adhesives (lower at temperatures
below 100 C, higher at high temperature). 3M recommends that signs
be manufactured within the 160 to 280 C temperature range.
Once prismatic sheeting has been applied and the sign maintained
within the recommended temperature range for 2 hours (to ensure good
bonding to the substrate), it can be stored at the temperatures a finished
sign may experience in use.
♦ Humidity:
It is recommended that the humidity in the storage areas for unused
sheeting and in the sigmaking facility itself be between 40 to 60%.
Higher humidity can slow the drying of screen print inks and may cause
changes to the flatness of materials with paper liners. In low humidity,
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3M Production Standards Manual for Permanent Prismatic Signs
static is increased especially in unwinding operations and liner removal.
This can cause dirt pickup which contaminates exposed adhesive and
the top surface of sheetings, can cause problems with electronic
equipment and may inflict surprising shocks to workers.
♦ Static electricity
To minimise the effect of static electricity it is recommended that all
equipment be grounded. In addition, during roll winding and unwinding
operations discharging the reflective sheeting by means of copper tinsel
or similar is also recommended.
♦ Cleanliness:
Premises must be clean, dry and relatively dust free. This is especially
true in areas where screen and digital printing is done as airborne dust
inevitably becomes incorporated into the finished graphic creating visual
flaws.
3. Substrate preparation
3M prismatic materials use aggressive pressure sensitive adhesive
designed for excellent adhesion to traditional metal signs substrates used
to make permanent signs. These include aluminium and galvanized steel.
Other substrates are not recommended by 3M except when 3M conclude
that the results of specific compatibility testing (done by a 3rd party test
house and conducted on behalf of the substrate supplier) demonstrate its
long term compatibility with 3M sheetings.
Plastic substrates such as polyethylene, polypropylene, glass reinforced
polyesters (GRP), etc. are not generally recommended (except when
evaluated as indicated above) because their formulation and batch to batch
quality can vary from supplier to supplier.
Stainless steel is not a suitable substrate.
3M prismatic sheetings can be applied to all classic types used in Europe:
♦ aluminum profile frame, bent edges, drilled face;
♦ extruded aluminum profiles
♦ flat metal sheets
Critical to the successful adhesion of sheetings to every substrate is the
correct preparation of the bonding surface. Correctly prepared surfaces
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3M Production Standards Manual for Permanent Prismatic Signs
must be flat, clean, grease free dry and corrosion free. Flatness is
important to ensure uniformity of the reflective surface of the finished sign.
Dirt, oil or grease (even oil from fingers), moisture or corrosion on the
substrate will reduce adhesive bonding and make a signface more likely to
lift, crack and fail in service.
Two easy tests to check whether surfaces are clean and grease free prior
to application are:
Test 1 – “Tape snap” test for cleanliness
Firmly press a piece of 3M Scotch tape or other transparent self adhesive
tape to the substrate surface and then snap it up. If there is any dirt on the
tape or some visual changes on the substrate’s surface it is not clean
enough for application.
Test 2 – “Water break” test for oily contamination
Pour water on the substrate surface. If the water flows out forming a
uniform film over the entire surface it is sufficiently degreased. If water
beads up in any area the surface has not been thoroughly degreased.
More detailed substrate preparation advice follows:
3.1. Aluminum
Aluminium is most frequently used substrate for large and small permanent
traffic signs.
For the best results use etched and degreased aluminum or anodized
aluminum. If these are used, degreasing with isopropyl alcohol is
sufficient preparation. If using industrial grade isopropyl alcohol it should
be mixed 1 part alcohol with 2 parts of water. Rubbing alcohol can be
used undiluted. Degreasing should be done with clean lint free paper or
cloths. Keep changing to new, clean paper or cloths until no dirt is
evident. Degreasing should be done just prior to application to avoid
new contamination of the surface with airborne dust. After cleaning and
before application check that the surface is completely dry.
For other types of aluminum there are additional procedures for proper
substrate preparation before cleaning with alcohol.
If the surface is badly pitted or oxidized use a commercial acid
brightener to recover it first. Then rinse with water and dry before
degreasing with isopropyl alcohol.
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3M Production Standards Manual for Permanent Prismatic Signs
If the surface is uncoated or unetched, remove white rust (oxidation)
first, then smooth it with 100 grit or finer abrasive and finally degrease it
and etch. After etching rinse with water and dry before degreasing with
isopropyl alcohol.
If the aluminum must be conversion coated with an amorphous
chromate remove white rust (oxidation) first, then smooth it with 100 grit
or finer abrasive and degrease. Then rinse with water and dry before
conversion coating. Only after that the substrate is ready for degreasing
with alcohol.
If possible, do not coat the side where sheeting will be applied.
The chromate conversion coating must be light and adhered tightly with
no powder residue. Optimum coating weight should be 1.1 to 3.8
mg/dm2 with a median of 2.75 mg/dm2.
Sheeting adhesion may be reduced if the coating is too heavy, if it is
dusty or is not tightly bonded within itself or to the substrate.
If the aluminum surface has to be painted, remove white rust (oxidation)
first, then smooth with 100 grit or finer abrasive and finally degrease.
Then rinse with water and dry before painting. Only then is the substrate
ready for degreasing with isopropyl alcohol and application of a
signface.
It is recommended that the side where sheeting is applied is not painted.
Do not use paint or powder coating that contains migratory agents or
silicones, chlorinated waxes or other ingredients that will reduce the
surface energy of the substrate causing poor or no adhesive bonding.
Also avoid paints which tend to chalk or bleed because they too will ruin
the chances for good adhesion.
3.2. Galvanized steel
If aluminium cannot be used, galvanized steel is the next best option. Test
the quality of the galvanized protection layer and then follow the
instructions from its producer for correct degreasing and edge protection of
newly cut edges to maintain the galvanization company’s warranty for
corrosion protection.
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3M Production Standards Manual for Permanent Prismatic Signs
Do not use products that contain migratory agents or silicones, chlorinated
waxes or other ingredients that will reduce surface energy of the substrate
thereby reducing or eliminating adhesive bonding. Also avoid finish paint
which tends to chalk or bleed because they too will ruin the chances for
good adhesion.
Finally, before sheeting application the substrate face side should be
cleaned with isopropyl alcohol using clean lint free paper or cloths.
More detailed discussion and recommendations on surface preparation
found in 3M Information Folder IF 1.7 which can be found on the 3M UK
TSS website at 3M.co.uk/traffic.
4. Sign making
The primary steps of the sign manufacturing process are presented on a
block diagram on Figure 2. These are the same process steps and
equipment used with glass beaded materials but some settings and
chemicals may be different.
Figure 2 – The sign manufacturing process
It is important to emphasis that all recommendations from this document
are for manufacturing signs from prismatic materials (EGP, HIP and DG3)
and could be different to those for other sheeting types.
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3M Production Standards Manual for Permanent Prismatic Signs
4.1. Storage and handling of unapplied sheets and rolls
3M prismatic rolls, cut sheets and smaller cut pieces should be stored
under the same recommended conditions as other reflective materials.
Storage should be in a cool, dry, indoor area, preferably at 18 – 240C and
30 – 50% relative humidity.
Full and partial rolls should be stored horizontally in the original package
boxes suspended on the end caps supplied.
If no original box is available, rolls should be supported horizontally by a
pipe or rod through the core. Rolls must not be set directly on their sides
because pressure marking is likely due to the roll’s weight. Rolls not stored
in a box will be exposed to airborne dirt. Ensure that sheeting used to make
signs is clean.
Cut sheets should be stored horizontally on the shelves in piles of no more
than 50 sheets wrapped in plastic. Smaller cut pieces (letters, symbols, etc)
should be wrapped in plastic and also stored horizontally.
As with glass beaded sheetings, caring must be taken during handling not
to scratch, bang or dent prismatic sheeting. Damaged reflective sheeting
surfaces cannot be repaired. Small scratches visible under close inspection
may also be visible at night when the sign is in use.
4.2. Sheeting preparation
Rolls of prismatic sheeting are often converted to sheets prior to
manufacturing operations such as screenprinting. When designing and
planning sign production there are some important aspects to consider
prior to cutting sheets.
4.2.1. Planning of sheeting use
Mixing
Do not mix different types (beaded and prismatic) or different grades (class
R2 and R3B) of retroreflective sheeting on the same sign. Whilst there are
no adhesion issues, the differences in retroreflectivity and daytime colour
among materials may result in a sign that looks less uniform than is
desirable.
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3M Production Standards Manual for Permanent Prismatic Signs
Colour matching
To optimize colour uniformity on large signs it is recommended that the
matching of sheeting,, as described in Figure 3 and 4,, is done.
Figure 3 – General matching rule when cutting sheets from the roll
Figure 4 – General matching rule for continuous application from the roll
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3M Production Standards Manual for Permanent Prismatic Signs
Orientation
Reflective sheetings are made in a linear process and have two
recommended orientations - 00 or 900 as shown in Figure 5.
Figure 5 – Orientation of the prismatic sheeting
On larger signs using 2 or more panels, ensure that all panels are applied
in the same orientation. HIP and EGP have more obvious stripes making it
easy to detect the orientation of any panel (stripes horizontal or vertical).
DG3 has a subtle, thin, parallel groove within the sheeting in line with the
unwind direction of the roll.
Using sheeting in orientations other than 00 or 900 are not recommended
for any of these prismatic sheetings as material performance is not tested
or certified at other orientations.
Figure 6 – Planning the cutting of prismatic sheeting
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3M Production Standards Manual for Permanent Prismatic Signs
4.2.2. Cutting prismatic sheeting
3M prismatic sheeting can be cut from either side and may be done by:
♦
♦
♦
♦
♦
♦
hand cut with scalpel or scissors
roll cut by special slitting machines
guillotine cut manually or via pneumatic guillotine
die cut
plotter cut on flatbed and drum cutters
laser cut
Flatbed cutters must have sufficient downforce to cut these tougher and
thicker sheetings. Roll plotters must also have a robust enough material
handling capability to work with heavy rolls and thicker, stiffer material
without slippage. Many drum plotters used for commercial signmaking will
not be robust enough. Table 1, below, shows the results of cut testing (in
partnership with the manufacturers) of the most frequently used plotter
cutters on European market.
Signmakers often find it more practical to cut 3M ECOF series 1170
transparent overlay film and laminate that to a background sheet of
prismatic material than to modify existing cutting equipment for prismatic
cutting. A more detailed explanation of the ECOF film method is given in
the section 4.4.
Good cutting results may be achieved using laser cutting devices. The
cutting shape is usually clean and precisely defined, but edges are
sometimes discoloured by the temperatures generated. In addition, it is
difficult to adjust the cutting depth, making kiss cutting (cutting sheeting, but
leaving liner intact) difficult.
More detailed discussion and recommendations for cutting 3M prismatic
sheetings may be found in 3M Information Folder IF 1.10 which can be
found on the 3M UK TSS website at 3M.co.uk/traffic.
13
there is no device that
can cut new prismatic
sheeting
no suitable
models
no suitable
models
Mimaki
Ioline
Panther
Vinyl Express
FC8000-130
there is no device that
can cut new prismatic
sheeting
no suitable
models
Summagraphics
Graphtec
there is no device that
can cut new prismatic
sheeting
M - 800
M - 1200
M - 1600
- initial setting cutting
force settings 35
- initial setting speed 9
- 600 g of down force
- two additional pinch wheels
- knife PLTB – Roland – 60
- knife holder model
PLTA-GRC-BLDHLD-HD
- knife down force
300mm
- 10000 mm/s speed
- push roller kit OPH-A22
- knife CB15U-K30
- blade holder PHP32-CB15U
- knife Z4
- knife holder C2 with gliding
disc
- can cut only small
symbols and letters
- pinch wheels leave
marks
- can cut all colours
and shapes
- pinch wheels can
leave marks on the
sheeting
can cut all colours and
all dimensions and
shapes
can cut all colours and
all dimensions and
shapes
Zünd
Systemtechnik
- cutting pressure
1.4 – 2 bar
- 1000 mm/s speed
ARISTOMAT
SL1317
Aristo Graphic
Systeme
- knife 07132
- pneumatic head
- knife underlay 1mm grey
there is no device that
can cut new prismatic
sheeting
no suitable
models
Notes
Mutoh
Recommended
settings
there is no device that
can cut new prismatic
sheeting
Cutting accessories
no suitable
models
Model
Roland Digital
Group
Producer
3M Production Standards Manual for Permanent Prismatic Signs
Table 1 – Plotter cutting of 3M prismatic sheeting
(Those highlighted in yellow are 3M recommended solutions)
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3M Production Standards Manual for Permanent Prismatic Signs
4.3. Screen printing
Screen printing of 3M prismatic sheeting uses the same types of equipment
and screens as have been used for decades to print beaded materials.
3M Scotchlite Process Colour Series 880i is the appropriate ink series for
screen printing all three classes of 3M prismatic sheeting – EGP, HIP and
DG3.
The tips on accessory materials for screen printing are listed below.
♦ 3M series 880i screen print ink only
♦ 880i ink is supplied ready to print – no thinning required when new
♦ thin only to a maximum of 10% with 889i if ink has been opened more
than once and /or hot conditions have caused significant evaporation
♦ mix ink thoroughly
♦ the coverage of ink series 880i is 25 - 30 m2/l
♦ adding of other chemicals (retarder, hardener, etc.) to the ink series
880i is not recommended
♦ use 61-64T mesh size monofilament polyester screens
♦ mesh tension on the screen should be 16-18 N (1-2% mesh
stretching)
♦ use water soluble stencil films or direct emulsion stencil materials that
are resistant to all solvents and thinners used
♦ use sharp (no knicks or grooves) rectangular rubber squeegee with a
65 shore hardness
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3M Production Standards Manual for Permanent Prismatic Signs
Drying notes
Type of
drying
Air
drying
Flow out
time1
Drying time Drying time
between
after final
colours
colour
during whole
drying time
Oven
drying
10 min
Conveyer
drying
1 min
3 hours
5 hours
Other notes
- drying shelves at least 5cm
apart
- hardboard support under
sheeting
- 0.5m/s permanent air flow
- low temp and high humidity
may lengthen drying time
- drying shelves at least 5cm
apart
- hardboard support under
30 min
30 min
sheeting
- oven temperature 420C
- 0.5m/s permanent air flow in
oven
- the minimum length of drying tunnel is 10 meters
- print must remain at 550C for 3 minutes
- producer must find optimum settings for his conveyer unit
Table 2 – Drying of ink series 880i
Other tips and recommendations for screen printing:
optimum ink mixing is achieved by using an ink mixer set at 10002000 rpm, for at least 15 minutes then allow the ink to rest for 1 hour
before starting to print
The screen printing method is off-contact with fill and print pass
Effective air drying is done in a well ventilated area with permanent
air flow over all the prints. This prevents slow solvent evaporation
which can have harmful effects on the signface. For all drying details
see Table 2.
More detailed discussion and recommendations for screen printing 3M
prismatic sheetings may be found in 3M Information Folder IF 1.8 which
can be found on the 3M UK TSS website at 3M.co.uk/traffic.
1
It is important to obtain consistent air flow for all shelves on a drying rack. This is often
achieved using multiple fans at different heights
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3M Production Standards Manual for Permanent Prismatic Signs
4.4. Digital Printing
A system for digitally printing high quality, durable, warranted prismatic
traffic signs was introduced by 3M in 2008. The system consist of a
customized Durst UV curing ink jet printer; specific 3M print and cure
settings; 3M 8800 UV inks; 3M prismatic sheetings (EGP, HIP and DG3);
and appropriate 3M clear overlays. It is critical that the 3M required settings
for the Durst printer are used. These ensure that the correct amount of
each component ink is printed in the right pattern to achieve the specified
colours and the best image quality and that the resulting signfaces are
cured completely. The following settings are required when producing
digitally printed traffic signs on the Durst printer for the output to be covered
by the 3MTM MCSTM warranty:
Print Resolution:
Print Options:
o Print Quality:
o Print Direction:
o Dithering:
o Print Finishing:
Media Profile:
Ink Limit:
Colour Management:
Linearization:
UV Lamp Power:
400 dpi
4 Pass
Bi-Directional
Stochastic
Glossy
specific one for the sheeting being printed
Off
No ICC profile
No Linearization
16 (1 Lamp Curing)*
The only setting an operator may change is the media profile which is
specific to the reflective sheeting type that is loaded for printing. All other
settings must be as above to ensure the colours printed will meet the colour
boxes required and the signface, once laminated with appropriate 3M clear
topfilm, can be warranted.
Only unspliced 3M prismatic sheeting can be used in digital printing. The
separation between the printheads and the media is critical to achieving the
right placement of printed dots so that the resulting colour is correct.
For more details on digital printing please see the 3M 8800UV product
bulletin and Durst’s printer manual.
* The UV power of the lamps will deteriorate with time. Monitoring UV output regularly with a
UV Integrator/radiometer is recommended. Refer to the Durst Operating Manual for detailed
maintenance intervals for the lamps.
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3M Production Standards Manual for Permanent Prismatic Signs
4.4.1. Application of overlaminate to digitally printed output
Digitally printed graphics must be laminated with 3M clear film approved for
this purpose to achieve the gloss, reflectivity and durability required for
traffic signs. The table below shows the approved overlaminate and
sheeting combinations and the warranty for each combination.
Clear Overlay
1170
1160 protective
1140
DG3
HIP
EGP
12
7
-
12
7
-
7
7
7
Table 3 - Warranty periods for approved sheeting/overlaminate
combinations
Lamination pressure, media alignment and other conditions are important
to achieve finished signs of the best quality. Incorrect settings, pressures,
etc. can result in a silvery appearance to finished graphics caused by air
entrapment between the clear overlay and the reflective sheeting. This
silvering can be detrimental to reflectivity as well as to the visual quality of a
finished sign. 3M recommend that a Crest 1400/1600 laminator be used.
The settings and specification for that laminator or any other laminator
being considered for finishing 3M digital prints are:
Roll diameter: max. 350 mm
Roll weight: approximately 80 kg
Roll width: 1400-1600 mm
Core size: 3 inches
2 Take-up shafts
2 Supply shafts
Heatable top roller: min. 45°C
Pressure: > 8 bar
Laminator speed: < 1 m/min
4.5 Application of sheeting to panels
There are two general categories of permanent traffic signs in the UK.
♦ Standard traffic signs (regulatory and warning signs ). These are
often symbolic signs made using predetermined designs in a set
range of sizes. These signs lend themselves to production in larger
quantities.
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3M Production Standards Manual for Permanent Prismatic Signs
♦ Directional traffic signs- These inform and guide drivers at a particular
point of a road and/or junction and therefore use bespoke designs.
The size of these signs is determined by the content desired and by
the text size needed for drivers to read them when travelling at the
speed of the road on which it will be installed. As a result these are
often large signs.
The production and application technique used for smaller signs and/or
those of standard design may differ from those used to manufacture larger
and bespoke signs. Regardless of sign size, successful lamination requires
good pressure to achieve bonding and to exclude air. The summary table
below gives the recommended pressure to use when following different
approaches to lamination.
Table 4 – Laminator Adjustment Overview for Sign Sheeting Applications
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3M Production Standards Manual for Permanent Prismatic Signs
4.5.1. Making smaller signs (i.e. regulatory & warning signs)
For smaller signs, a standardized approach to application is often taken.
The conditions in the application area must be those described in
section 2 of this document.
The application substrates must be prepared as described in section
3 of this document.
Follow the recommendations for sheeting orientation (section 4.2.1.).
Follow screen printing recommendations from section 4.3 of this
document.
Prior to application, the sheeting and substrate must be conditioned
for 24 hours at room temperature (180 - 220C).
When applying using a squeeze roll applicator or Rolls Roller set the
pressure to 3.5 – 5.5 bar (350 – 550 kPa) depending on laminator
model. Typically a Rolls Roller should be set closer to 5 – 5.5 bar.
Using an application pressure that is too low can cause wrinkles or
edge lifting. Too much pressure can damage the sheeting structure
reducing the retroreflectivity and cause wrinkles.
If hand applying, use a hand roller no wider than 5 cm (wider rollers
do not evenly apply pressure). For small symbols or letters a 3M PA1G gold applicator with SA-1 low friction sleeve may be used.
For multi-panel signs only butt-joining of prismatic sheeting is
recommended. Overlapping is not recommended because of the
thickness of prismatic sheetings. Vertical butt splicing is
recommended because water then runs naturally off the sign face.
Horizontal splices may allow water to persist or ice to form on the
traffic sign. These recommendations are illustrated in figure 7.
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3M Production Standards Manual for Permanent Prismatic Signs
Figure 7 – Recommended butt splicing for prismatic sheeting
Many regulatory and warning signs are made by applying selfadhesive, non-reflective black symbols to the white background of the
sign. The symbols premasked with a 3M tape are laminated to the
sheeting using the same application equipment and techniques
identified in section 4.4. The following 3M products are recommended
for this application:
Durability
12 years
Recommended black non-reflective products
3M Scotchcal 7725 or 100 series
3M Electrocut 1178
3M Controltac Scotchcal Film 180-12
3M TFEC 260D lettering film
7 years
3M Scotchcal Film 70-12
5 years
3M Scotchcal Film 50-12
3 years
3M Scotchcal Film 30-12
3M Application Tapes for use in this application are
- SCPM-19 opaque, lower tack, for larger symbols
- SCPS2
opaque, higher tack for smaller graphics
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3M Production Standards Manual for Permanent Prismatic Signs
3M TPM-5 clear, non-stretch tape for use with ECF 1170Following
application of
the premasked symbol, remove the application tape and re-roll the
sign through a Squeeze Roll Applicator or Rolls Roller.
If a clear anti-graffiti overlay is specified, cover the sign face with 3M
Premium Protective Overlay Film Series 1160. Film series 1150 (a
polyester overlay) is not the preferred overlay as it is less effective
against graffiti and reduces the reflectivity of the finished sign by as
much as 10%.
4.5.2. Manufacturing of large signs
Large, multi-panel signs are typically made in one of three ways:
- Scotchcal opaque and/or 3M ECOF transparent coloured overlay film
applied onto sign panels previously applied with white background
reflective sheeting
- cut and applied reflective text and symbols are applied onto sign
panels previously applied with reflective of the same sheeting type in
the desired background colour (white, blue, dark green)
- Digitally printed reflective sign panels applied to metal sign panels
The first method using transparent coloured overlay films applied to white
reflective background sheeting is explained below:
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3M Production Standards Manual for Permanent Prismatic Signs
Using most available models of plotter cutter, cut 3M ElectroCut Film
Series 1170 (Figure 8) into the text and symbols appropriate for the
sign. Use a setting of approximately 100 grams cutting pressure.
Figure 8 – Plotter cutting the 3M ECF 1170
Immediately after the cutting operation remove excess film – weeding
(Figure 9).
Figure 9 – Weeding operation on cut ECF 1170
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3M Production Standards Manual for Permanent Prismatic Signs
Apply 3M Application Tape to the face side of the cut and weeded EC
film. (Figure 10). These graphics are now premasked.
Figure 10 – Applied application tape over ECF 1170
When all graphic elements of the sign face made from ECF 1170 are
ready, the sign manufacturing process continues with application of
background white prismatic retroreflective sheeting (Figure 11).
Figure 11 – Application of background white prismatic reflective sheeting
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3M Production Standards Manual for Permanent Prismatic Signs
Squeeze Roll lamination pressure should be set within the 3.5 – 5.5
bar (350 – 550 kPa) range. The pressure varies with different
laminator models. Initial testing should be done by the signmaker to
ensure that lamination pressure is optimized to provide good bonding
of the reflective sheeting and of overlays with the equipment used.
For a Rolls Roller the lamination pressure for 3M prismatic reflective
sheetings should be to 5 – 5.5 bar.
After the application of background white retroreflective prismatic
sheeting to the sign panel, carefully align the premasked ECF graphic
with the sign panel. Fold back the leading edge of the graphic and
remove 5 – 10 cm of EC film’s liner (Figure 12).
Figure 12 – Positioning of ECF and initial removal of liner
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3M Production Standards Manual for Permanent Prismatic Signs
Hand apply this leading edge portion, preferably with a hand roller
(Figure 13). This will fix the ECF and prepare it for application in the
squeeze roll applicator.
Figure 13 - The hand application of ECF leading edge
After fixing the edge, the panel end with ECF is inserted into the roll
applicator and rest of the premasked ECF is pulled back and over the
application roller (Figure 14) so the application is visible.
Figure 14 – Puling back of ECF over the application roller
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3M Production Standards Manual for Permanent Prismatic Signs
Remove the liner from the ECF (Figure 15) either prior to or during
lamination. Apply the ECF onto the background prismatic sheeting
(Figure 15). Check (and if necessary re adjust) pressure on the
applicator. When laminating ECOF with a Rolls Roller use 2 bar.
Figure 15 – Removal of liner from ECF
After the ECF is applied, remove the application tape (Figure 16)
Figure 16 – Removal of the application tape
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3M Production Standards Manual for Permanent Prismatic Signs
If there are additional symbols in different colours they may be
applied separately. Cut, weed and premask them and either hand
apply (Figure 17) or laminate with a squeeze roll laminator (Figure
18). Remove application tape from these additional pieces, too.
Figure 17 – Hand application of small symbols in different colours
Figure 18 –Application of additional symbols by a squeeze roll applicator
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3M Production Standards Manual for Permanent Prismatic Signs
After all parts of the sign panel have been applied and all application
tape removed, re-rolled the entire panel in the squeeze roll laminator.
If 1160 clear overlay is desired on the finished sign, it can be applied
during the re-rolling step for each sign panel. (Figure 19)
Figure 19 – Application of transparent anti-graffiti protective film
If splicing of ECF overlay is required either butt or overlap slicing may
be used. Any butt splices should be vertical on the installed sign face.
Only use overlap splice which are horizontal on the installed sign with
an overlap of approximately 3 mm of the upper section over the
lower.
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3M Production Standards Manual for Permanent Prismatic Signs
Figure 20 – A finished directional sign made using white 3M prismatic
retroreflective sheeting overlaid with blue, green and red ECF 1170 and
black opaque graphics and protected from graffiti with 3M 1160 protective
overlay film
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3M Production Standards Manual for Permanent Prismatic Signs
5. Packing and storage of finished traffic signs
Careful handling of finished signs will ensure that no damage is incurred
during storage, shipment, handling and installation.
Prior to packing signs made with 3M prismatic sheeting cover the entire
face with a slipsheet made from 3M slipsheeting SCW-568 or with liner
from EGP, HIP or DG3 using the glossy side against the face. Do not allow
adhesive tape used to hold slipsheets in place to bond to the reflective face
of the sign.
Pack signs in pairs, face to face with plastic bubble wrap between and
around or individually in bubble wrap, paper, cardboard or plastic covers.
Plastic bubble wrap helps reduce the chance of damage to the prismatic
cells that could result from bumps and bangs. Prismatic sheeting is more
robust that beaded sheeting but can still be damaged by rough handling.
When storing finished signs indoor place them face to face on edge, on
wooden battens (to prevent edge damage). Wooden battens should be
constructed in such way that they will permit air to circulate by the signface.
When storing finished signs outdoor or in closed metal storage containers
remove all packing material including the slipsheeting so that nothing is in
contact with the sign face. Store signs on edge on wooden battens that
provide at least a 5 cm gap between sign faces.
Also avoid bending, crating or stacking in a manner which puts finished
signs under pressure. It is not recommended that signs be placed face
down on any surface or that objects be placed on the sign face.
If packed signs get wet remove all packaging, dry the signs, then repack
them in new dry material and store in dry conditions. If it is likely that signs
will become wet again it is recommended not to storage them as if they
were stored outdoor.
More detailed discussion and recommendations for storing, packing and
handling finished signs made with 3M prismatic sheetings may be found in
3M Information Folder IF 1.11 which can be found on the 3M UK TSS
website at 3M.co.uk/traffic.
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3M Production Standards Manual for Permanent Prismatic Signs
6. Trouble shooting guide
6.1. Handling prismatic sheeting
CONDITION
POSSIBLE CAUSES
CORRECTIVE STEPS
1. Sheets do not lay
flat in a stack.
moisture absorption or loss
Store materials in an
environmentally controlled area
(160C-280C) and 30% - 60%
relative humidity. If necessary,
place a flat panel such as
plywood and a small amount of
weight on the stack. After the
stack has flattened, wrap in
plastic polyethylene for storage.
2. Poor adhesion of
applied sheeting
A. Substrate contaminated test by spraying or sprinkling
water on the sign panel. If it
beads up rather than flowing
out evenly on the surface, the
panel may have oil, wax or
fingerprints on it.
Substrates should be properly
prepared as detailed in section
3. Aluminium must be etched
scrubbed using a 3M ScotchBrite scouring pad or steel wool
and abrasive cleaner.
B. Sign panel dirty of “gritty”
Use a “tack” rag to wipe the
debris from the surface, then
solvent wipe with IPA or
ethylated spirits.
C. Sign panel not properly
prepared. The surface may be
too smooth or may have loose
phosphate of chromate
conversion coating. Painted
surfaces may be
contaminated with waxes,
silicone or other agents.
Panels should be properly
prepared as stated in section 3.
A. Sign panels have not been
solvent wiped or solvent has
not completely evaporated.
Sign panels must be thoroughly
dry and solvent completely
wiped off prior to application. Do
not rely on evaporation.
B. Painted surfaces not
completely dry: escaping
solvent causes bubbling.
Paint must be completely dry
and cured before application.
Touch dry is often not sufficient.
Consult paint company for help.
32
3. Sheeting bubbles
during application
3M Production Standards Manual for Permanent Prismatic Signs
C. Sign panels are not dry.
4. Wrinkles in applied D. Screen print colour not
sheeting.
thoroughly dry: solvent is
causing adhesive to preadhere.
Panels must be thoroughly dry.
If sign panels are stored
outdoors or in an unheated area
during wet or cold weather, they
should be individually dried (not
in a stack) at shop temperature
for at least 24 hours before use.
Thoroughly dry screen printed
faces and emblems before
application.
A. Unapplied faces may
become wavy if exposed to
extensive moisture during
shipment or storage.
See item 1, under CONDITION
above.
B. Air between sheeting and
panel
Check laminator adjustments,
alignment and application
procedure
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3M Production Standards Manual for Permanent Prismatic Signs
6. Trouble shooting guide
6.2. Screen printing prismatic sheeting
CONDITION
POSSIBLE CAUSES
CORRECTIVE STEPS
1. Incomplete
coverage of Series
880 I Colours
(spots where ink
does not flow out
properly).
A. oily or waxy contamination
of the sheeting, screen, ink or
the air.
1. Avoid masking out the open
screen area with pressure
sensitive tape. Squeegee
action will often pull bits of tape
adhesive or release coating
into the image area causing
spotting.
2. If temporary films with soft,
oozy adhesive are also
converted, check the cutting,
jogging and screening areas
closely for evidence of
adhesive transfer. This type of
adhesive transfers very easily
to cutting and screening
equipment and is a common
cause of spotting.
3. Avoid use of silicone release
agents, silicone hand creams,
silicone lubricants etc. in the
shop.
4. Keep the screening and
substrate conditioning areas
separate from areas where
equipment using lubricants is
used.
5. Use new wiping rags or
cloths. Re-laundered rags
often retain some silicone or oil
contaminants.
6. Ensure that screen inks and
thinner are thoroughly mixed
and strained. Mix with a high
speed mixer.
7. Avoid touching a sheet in the
area to be screened. Handle
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3M Production Standards Manual for Permanent Prismatic Signs
sheets only in their waste edge
area. It may be helpful to wear
clean cotton gloves during
cutting or handling operations.
8. Wipe each sheet lightly just
before screening to remove
dust and airborne
contamination.
9. Use ink at higher viscosity.
If corrective steps 1-9 above do
not eliminate the problem
contact 3M.
2. Smeared copy.
3. Mis-registry on
multiple colours.
A. Colours running through
screen because of:
1) excessive thinning
2) careless fill pass
Remix and add more ink. Use a
firm clean fill pass: do not allow
ink to drip into the screen from
the squeegee blade.
B. Too much or too little offcontact.
Set off-contact so that only the
edge of the squeegee blade
contacts the surface. The
screen should lift cleanly from
the surface directly behind the
squeegee.
C. Dirty or poor quality stencil
Remake stencil. The stencil
must have clean edges.
D. Loose screen fabric.
Remake screen: fabric must be
taut and uniform.
E. Dull squeegee.
Sharpen or replace blade.
F. Frame loose in hinges.
Tighten hinges.
A. Loose screen fabric
Remake screen: fabric must be
taut uniform.
B. Loose hinges.
Tighten hinges.
C. Loose edge guides.
Reposition and tighten edge
guides.
D. Sheets not conditioned.
Condition sheets.
E. Misplaced sheet guides.
Guides must contact each
sheet at the same spot.
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3M Production Standards Manual for Permanent Prismatic Signs
4. Bubbling of Ink :
F. Block out filler applied after
stencil application causes
screen shrinkage.
Block out most of well area
before applying the stencil.
G. Too much off-contact (or
excessive or uneven lift on
large screens).
Reduce off-contact so that the
screen fabric “breaks” just
behind the squeegee.
H. Pulling squeegee in
opposite directions on
alternate sheets.
Make print pass in one
direction on all colours.
Minor bubbling of the
processed ink on the sheeting
may remain after screening
but should flow out during the
first 5 minutes of dry time.
Excessive bubbling may be
caused by :
A. Rapid movement of the
squeegee.
Make a slow, uniform print
pass.
B. Too much or too little offcontact.
Set off-contact so that only the
edge of the squeegee blade
contacts the surface: the
screen should lift cleanly from
the surface directly behind the
squeegee.
C. Bubbles do not flow out.
See NOTE below*.
D. No fill pass.
Always use fill pass.
E. Incomplete cleaning of
screen.
Thoroughly clean with
appropriate solvent.
F. Ink too thick or too thin.
Remix with thinner or more ink.
*
NOTE: If bubbles occur during screening, a strong air flow on processed areas can dry the
bubbles quickly and prevent them from flowing out. To avoid this, slow the fan speed or
increase the distance between fans and the racks but DO NOT STOP AIR FLOW
COMPLETELY. Reducing the air flow too much will tend to allow solvents to concentrate and
slow evaporation, causing cracking as the colours dry.
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3M Production Standards Manual for Permanent Prismatic Signs
5. Orange peel
(small uniform
scaling patterns).
A. Ink too thick.
Remix with more thinner.
B. Ink not thoroughly mixed.
Mix thoroughly.
C. Wrong thinner.
Use only a recommended
thinner.
D. Screen lag (not lifting
directly behind squeegee
blade) cause by:
6. Applied ink
appears mottled:
7. Ink drying in
screen.
1. Too little off-contact.
Increase of off-contact.
2. Loose screen fabric.
Remake screen: fabric must be
taut and uniform.
3. Ink too thick.
Remix with more thinner.
E. No fill pass.
Always use a fill pass.
F. Not-allowing time for ink
flow-out before placing in the
oven.
Always allow 10 minutes flow
out time before oven drying for
ink series 880I.
A. Ink too thick
Remix. If still too thick, add
correct thinner (max 10%)
B. Ink not thoroughly mixed.
Mix thoroughly
C. Contamination.
Check nothing has been added
to ink and stirring equipment
was clean prior to use; if
thinned that recommended
thinner has been used.
D. Ink drying in the screen.
See Number 7 below.
E. Improper off-contact
Set off-contact so that only the
area under the edge of the
squeegee blade contacts the
surface: the screen should lift
cleanly from the surface
directly behind the squeegee.
A. Ink too thick.
Remix. If still too thick, add
correct thinner (max 10%)
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3M Production Standards Manual for Permanent Prismatic Signs
B. Delay between screening
passes.
Screen should not be left for
more than 1 minute, make a fill
pass and then print several
passes onto waste paper. If a
longer delay is necessary wash
bottom of screen with thinner.
C. Air draft on screening area.
Arrange circulation to avoid air
draughts.
D. Low shop humidity and/or
high temperature.
Increased humidity. If possible,
have screen shop air
conditioned.
8. Ink cobwebs at
copy edges
E. Wrong thinner.
Use only recommended
thinner.
9. Excessive dust
pick-up.
Static electricity.
Ground the table, screen and
sheeting with copper tinsel
and/or increase shop humidity.
Dusty environment
Seal floors and keep floors and
work area clean.
A. Ink trailing from squeegee
blade and running through
screen.
Move squeegee from side to
side in well area to “blot” it
before beginning print pass and
prevent ink from trailing from
rear edge of blade.
B. Ink drying in screen.
See Number 7 above.
C. Screen does not lift from
sheeting immediately behind
squeegee.
Increase off-contact. If
necessary, remix ink, adding
thinner if necessary.
D. Nick in squeegee.
Check squeegee blade and
sharpen or replace rubber if
necessary.
E. Nick or scratch in table top.
Refinish or replace table top. It
must be flat and smooth.
F. Squeegee too sharp.
Sand leading edge of freshly
sharpened squeegee with fine
sandpaper or emery cloth.
10. Streaks or marks
in the screened
area.
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3M Production Standards Manual for Permanent Prismatic Signs
11. Blurred edges on
screened area.
A. Ink too thin, and runs under
the stencil edges.
Remix adding more ink.
B. Ink drying at stencil edge.
See Number 7 above.
C. Squeegee not making a
firm impression at stencil
edge.
C & D:
1. Increase size of the well
between the frame and open
area of stencil.
D. Too much pressure on
squeegee forces process ink
under edge.
2. Use thinner stencil film.
3. Increase pressure on print
pass.
4. Use a harder squeegee
blade.
5. Reduce amount of offcontact.
12. Ink does not air
dry properly.
A. Concentration of solvent
vapors between shelves on
the drying rack slows rate of
evaporation.
Use high volume fans directed
into the drying racks to remove
solvent vapor.
B. High humidity and/or low
temperature.
Decrease humidity and
increase temperature if air
drying, or oven dry
C. Using too coarse mesh size Use recommended screen
mesh.
in screen.
13. Cracks in the
screened area:
A. Insufficient horizontal air
flow in the drying area.
1. Improve air flow.
2. Fans must work throughout
the drying time.
3. Air flow must be over all the
drying shelf and at all levels of
the rack.
4. Separate prints more by
putting them on every second
drying shelve. This allows more
air flow.
B. Insufficient exhaust air flow
from the drying area.
Improve exhaust to remove
solvent from drying area.
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3M Production Standards Manual for Permanent Prismatic Signs
C. High humidity or low
temperature.
1. Start dehumidification.
2. Install heater.
D. Rough handling of
sheeting.
1. Use smooth cardboard or
hardboard on drying shelves
under printed sheets to provide
uniform support.
2. Do not flex or bend sheets
when the ink is wet.
3. Avoid stretching sheeting
during application.
4. Print on already applied
sheeting.
E. Problem with ink
preparation
1. Use only ink series 880 I
2. Avoid adding thinner to the
ink.
14. Sheet curl.
Sheeting retains curve of the
roll
Roll sheets gently against curl
or stack sheets in pack
overnight.
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3M Production Standards Manual for Permanent Prismatic Signs
6. Trouble shooting guide
6.3. Digital printing
CONDITION
POSSIBLE CAUSES
CORRECTIVE STEPS
1.Printed signs are
still wet exiting the
printer
1.UV curing has not occurred
1.UV lamps may be old or
not working. Wear protective
gloves when handling wet
prints. Check the UV lamp
power settings and measure
delivered power using the
technique recommended by
Durst.
2. colours being
printed look
wrong
A.Print settings are incorrect
1. Ensure no ICC colour
profiles or linearization are
being used and that stochastic
dithering is being used.
2. Ensure that the colour fill
levels are set correctly for the
media being used.
3.Ensure all other required
settings are correct
B. jets in the printhead may be 1.Follow Durst’s procedure for
clogged
conducting a jet test and purge
if necessary
3. laminated prints
look silvery
A. Lamination settings are not
correct and air has been
trapped between print and
overlaminate
1. Check that lamination
pressure, speed and heat
settings are correct.
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3M Production Standards Manual for Permanent Prismatic Signs
6.4. Handling finished signs and sign faces
CONDITION
POSSIBLE CAUSES
CORRECTIVE STEPS
1. Processed sheets
block (stick)
together when
stacked
A. Final colour not thoroughly
dry.
Colours must completely dry
before packaging. Increase air
dry time with high volume fans
blowing through racks or over
cure if necessary.
B. Material subjected to
excessive heat and/or
pressure.
1. Avoid exposing material to
excessive or direct heat during
storage or shipping.
2. Reduce stack size to avoid
high pressure on lower sheets.
Sign faces can be stacked
temporarily (in process) on a
smooth, rigid base to the height
of 50 sheets without
interleaving slipsheets.
2. Surface
impressions on
processed sheets.
A. Final colour not dry.
Check drying before stacking.
B. Stack is under pressure or
the stack is exposed to
excessive heat.
Avoid exposing stacks to
pressure or excessive direct
heat.
3. Finished signs
stick together.
Signs were stored flat and
pressure caused blocking.
Store signs on edge, with
spaces between slipsheeted
signs.
4. Stored signs show
dark spots or
blotches on face.
A. Moisture trapped against
signface – between slipsheet
and sign or sign stored face
down on a damp surface.
Store signs on edge in a cool
dry area, with spacers to allow
good air circulation and prevent
moisture from being trapped
between closely stacked signs.
B. Signs become wet during
storage and moisture is left in
contact with the sign face.
Signs that become wet in
storage should be unpacked
and stored on edge.
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3M Production Standards Manual for Permanent Prismatic Signs
5. Unapplied faces
wrinkle and
separate from
liner.
Signface is rolled the wrong
way (liner side out).
If sheets must be rolled, roll
face side out around a core
with a minimum 8,3cm
diameter. Otherwise ship
emblems flat in crates.
6. Cracked edges on
emblems.
A. Emblems are packed too
loosely in shipping package.
Emblems must be packaged to
prevent movement during
shipment.
B. A dull cutting tool was
used.
All cutting tools must be sharp.
Faces bent too sharp.
Faces must be handled
carefully.
7. Cracks in
unapplied faces.
43