Production Manual for
Manufacturing of
Permanent Quality Signs
with
3MTM Prismatic Sheeting Series
(DG34090, HIP3930 and EGP3430)
3M Germany GmbH
Display & Graphics Laboratory
Carl-Schurz-Str.1
GE-41453 Neuss
Germany
21st April, 2011
Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
Table of contents:
1. Introduction
2
2. Signshop conditions
4
3. Substrate preparation
6
3.1. Aluminum
7
3.2. Black metal or steel
8
3.3. Galvanized steel
9
4. Permanent Sign making
10
4.1. Sheeting storage and handling
12
4.2. Sheeting preparation
12
4.2.1. Planning of sheeting use
12
4.2.2. Cutting of sheeting
15
4.3. Screen printing
17
4.4. Application of sheeting
19
4.4.1. Manufacturing of standard signs
20
4.4.2. Manufacturing of large signs
22
5. Packing and storage of finished traffic signs
32
6. Trouble shooting guide:
33
6.1. For handling prismatic sheeting
33
6.2. For screen printing on prismatic sheeting
35
6.3. For handling finished signs and sign faces
42
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
1. Introduction
The latest developments in sign making materials from 2005 onwards are
represented in the new generation of 3M prismatic sheeting. The three
newly developed materials are 3M Engineer Grade Prismatic (EGP)
Reflective Sheeting Series 3430, 3M High Intensity Grade Prismatic (HIP)
Reflective Sheeting Series 3930 and 3M Diamond Grade (DG3) Reflective
Sheeting Series 4090 and 4080 Fluorescent. The EGP is categorized as
Class 1 retroreflective material, HIP is categorized as Class 2 and DG3 is
Class 3 according to EN 12899 and CUAP.
All new materials provide better night and day performances of finished
traffic signs comparing to the old Class 1, 2 and 3 materials. This was
gained by introducing new technologies and by optimization of shape of
non-metalized micro prismatic lenses. As a consequence the new sheeting:
♦ Reflects more light (more efficient);
♦ Has better angularity;
♦ Is whiter than old types (the old white Class 2 materials with glass
beads were appearing slightly silver/grey in day time in close range);
♦ Is less sensitive on production conditions;
♦ Is more resistant.
The subject of this document is not the presentation of new materials and
comparison with old ones. Instead, this document gives guidelines for sign
producers to adopt new materials in their production. This is done with the
smallest possible changes in manufacturing equipment and technology. In
addition this document will provide guidelines how to avoid any difficulties
and possible problems in manufacturing process. Further more, it will
outline the most cost effective production methods. Finally, by adopting
these materials and recommendations it will give manufactures the edge
concerning competition issues.
Figure 1 shows a close view of new materials. The difference between
them is easy recognizable. HIP sheeting has parallel skip lines on the
surface in the direction of the unwinding roll. In comparison to this, DG3 has
a clear uninterrupted “diamond network”.
In addition, all materials have the same tooling lines and seal pattern legs
like the old Diamond Grade materials and, as with the previous products,
they are only visible on close inspection and do not interrupt day or night
performances of the finished signs.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
unwinding direction
Close view of 3M EGP material
Close view of 3M HIP material
Close view of 3M DG3 material
Figure 1 – Close view of new materials
Finally DG3 material is available in white, yellow, red, blue, green,
fluorescent yellow, fluorescent yellow-green and fluorescent orange color.
HIP is available in white, yellow, orange, red, blue and green color. Both
materials are not available in brown. EGP is available in white, yellow, red,
blue and green color. All three materials are not available in brown color.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
2. Signshop conditions
As with most retroreflective materials this new prismatic sheeting has some
specific requirements concerning conditions in work space. It is typical for
EGP, HIP and DG3 materials that are less sensitive to production
conditions but there are some limits that must be followed:
♦ Temperature requirements:
The temperature in the premises where traffic signs are manufactured
should be between 180 and 220 C. A lower temperature is allowed only
in the storage room for finished products.
If there is no temperature control and no heating system in the signshop,
it is still possible to manufacture traffic signs within certain limitations.
These are dictated mostly by screen printing requirements (160 to 280
C). This is because new prismatic sheeting is thermo stabile, has
aggressive adhesive properties and is generally not very temperature
sensitive.
Temperatures that are too low cause changes in the ink viscosity and
the screen printing becomes almost impossible. Only very low
temperatures (lower than 100C) can cause sheeting to crack. If the
temperatures are higher than the suggested maximum, screen printing
is more difficult because the ink dries faster and it closes the screen
faster. The new prismatic sheeting can withstand a high temperature
very well and applications up to 300 C were done without any problem.
♦ Air humidity:
In the premises for traffic sign manufacturing and sheeting storage air
humidity should be maintained within limits of 40 to 60%.
Air humidity control is necessary since some complications may occur in
the manufacturing process very similar to those previously described
when temperature control is absent.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
♦ Static electricity:
It is typical for all prismatic sheeting that this can cause problems so it is
essential to ground all equipment and sheeting to avoid spontaneous
discharging, flame hazard and uncomfortable working conditions.
♦ Clean and tidy premises:
This is nothing new for sign manufacturers. Premises must be clean, dry
and dust free. The difference to other retroreflective sheeting is that in
this case it is crucial for the quality of the final products if they are
screen printed.
Due to the high static electricity potential of the new materials, especially
after screen printing, all airborne dust will be attracted to the freshly
printed surface.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
3. Substrate preparation
The new prismatic materials have aggressive pressure sensitive adhesive
which is designed for all classic types of metal blank materials. Namely
they can be applied on blanks from:
♦ aluminum;
♦ black metal or steel;
♦ galvanized steel.
All other types of blank materials are not recommended. On exceptional
bases some plastic substrates can be used subject to priory testing by
converter.
Stainless steel can not be used at all.
When considering the blank types, all classic types are acceptable:
♦ for standard signs – with an aluminum profile frame, bent edges and
a drilled face;
♦ for large signs – from extruded aluminum profiles or from flat metal
sheets on a steel backing frame.
It is important to emphasis that the correct selection of blank material and
its proper preparation are crucial for durability of final products – traffic
signs. The proper preparation means that the surface must be flat, clean,
dry and corrosion free.
In comparison to beaded sheeting, a flat blank surface is much more
important when using prismatic material for the sign face. In this case the
smallest uneven surface will be highly visible on the sign due to high glare,
retroreflectivity and the prismatic structure of the sheeting material.
There are two tests to check if the surface is clean and ready for
application:
Test 1 – “Tape snap” test
It is necessary to firmly press a piece of 3M Scotch tape or other
transparent self adhesive tape to the substrate surface and then to snap it
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
up. After that, if there is some dirt on the tape or some visual changes on
the substrate surface it is not clean enough for application.
Test 2 – “Water break” test
It is necessary to pour some water on the substrate surface. If the water
flows out forming a uniform film the surface is clean. Otherwise, if the water
beads up then the surface is not sufficiently degreased.
Depending upon which materials are selected there are different methods
of blank preparation:
3.1. Aluminum
Aluminum is a most favored material for traffic sign production (both police
signs and guidance signs).
For the best results it is necessary to use etched and degreased
aluminum or anodized aluminum. In this case it is enough to clean the
surface using isopropyl alcohol. If it is industrial grade isopropyl alcohol
it is necessary to mix it in a ratio of 2 parts of water to 1 part of alcohol.
In case of rubbing alcohol it is not necessary to dilute it. The cleaning
should be done with lint free paper or rag. If the paper or rag becomes
dirty it is necessary to change it until it collects no dirt at all. This
operation should be done immediately before application to avoid new
contamination of the surface with airborne dust. After cleaning and
before application it is necessary to check that the surface is completely
dry.
For other types of aluminum there are some additional procedures for
proper substrate preparation before cleaning with alcohol. Namely:
If the surface is badly pitted or oxidized use a commercial acid
brightener to recover it first. Then it is necessary to rinse it with water
and dry it before cleaning with isopropyl alcohol.
If the surface is uncoated or unetched it is necessary to remove white
rust (oxidation) first, then to smooth it with 100 grit or finer abrasive and
finally to degrease it and etch. After etching it is necessary to rinse it
with water and dry before cleaning with isopropyl alcohol.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
If the aluminum surface has to be conversion coated with an amorphous
chromate it is necessary to remove white rust (oxidation) first, then to
smooth it with 100 grit or finer abrasive and finally to degrease it. After
that it is necessary to rinse it with water and dry before conversion
coating. Only after that the substrate is ready for cleaning with alcohol.
If possible, it is recommended not to coat the face 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.
It is important to know that sheeting adhesion can be affected if the
coating is too heavy or the coating is dusty and not tightly bonded within
itself or to the substrate.
If the aluminum surface has to be painted it is necessary to remove
white rust (oxidation) first, then to smooth it with 100 grit or finer
abrasive and finally to degrease it. After that it is necessary to rinse it
with water and dry before painting. Only after that substrate is ready for
cleaning with isopropyl alcohol.
If possible, it is recommended not to paint the face side where sheeting
will be applied.
It is necessary to use paints that do not contain migratory agents or
silicones, chlorinated waxes or other ingredients in relative high ratios,
to which little or no adhesion can be obtained. In addition it is
recommended not to use finish paints which tend to chalk or bleed.
3.2. Black metal or steel
These materials are not so good for high durable products because of their
corrosion characteristics. In the event that they must be used proper
preparation is crucial. In this case, blanks must be painted or chromate
coated before application of the sheeting. It is important to know that in
both cases the face side does not need to be covered (only back and
edges from face) because sheeting will provide protection from corrosion.
The proper preparation in this case is:
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
If the surface is to be conversion coated with an amorphous chromate it
is necessary to remove rust completely from both sides and to degrease
it. Depending on the degreasing method it could be necessary to wash
the substrate with water. In this case it is necessary to dry steel
immediately to avoid any new corrosion. After that it is ready for
conversion coating. Finally, before sheeting application, the substrate
face side should be cleaned with isopropyl alcohol and clean lint free
paper or rag.
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 median of 2.75 mg/dm2.
It is important to know that sheeting adhesion can be affected if the
coating is too heavy or the coating is dusty and not tightly bonded within
itself or to the substrate.
If the surface is to be painted it is necessary to remove rust completely
from both sides and to degrease it. Depending on the degreasing
method it could be necessary to wash the substrate with water. In this
case it is necessary to dry steel immediately to avoid any new corrosion.
After that it is ready for painting. Finally, before sheeting application the
substrate face side should be cleaned with isopropyl alcohol and clean
lint free paper or rag.
It is necessary to use paints that do not contain migratory agents or
silicones, chlorinated waxes or other ingredients in relative high ratios,
to which little or no adhesion can be obtained. In addition it is not
recommended to use finish paints which tend to chalk or bleed.
3.3. Galvanized steel
In case aluminum can not be used, galvanized steel is the optimum
solution, much better than black metal. In this case it is necessary to test
the quality of galvanized protection layer and then to follow the instructions
from its producer for proper degreasing and painting. Namely after cutting
the sheets of galvanized material the edges would not be protected from
corrosion so it is necessary to paint them and depending on local standards
to paint completely the back side of the metal blank.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
In this case it is necessary to use paints that do not contain migratory
agents or silicones, chlorinated waxes or other ingredients in relative high
ratios, to which little or no adhesion can be obtained. In addition it is not
recommended to use finish paints which tend to chalk or bleed.
In addition to this it is necessary to ask the galvanization company to
provide a warranty for corrosion protection for at least 10 years (this is
prismatic sheeting warranty period).
Finally, before sheeting application the substrate face side should be
cleaned with isopropyl alcohol and clean lint free paper or rag.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
4. Sign making
The main operations of the sign manufacturing process are presented on a
block diagram on Figure 2. This is the same process as with old materials
(Engineer Grade, High Intensity and Diamond Grade) using mostly the
same equipment. Only some settings and chemicals are different
compared with the previous materials.
Figure 2 – The sign manufacturing process
Some operations shown in the above diagram were already explained
(preparation of traffic sign blank in previous chapter) and the rest will be
explained in the following text.
It is important to emphasis once more that all recommendations from this
document are for manufacturing signs from new prismatic materials (EGP,
HIP and DG3) and could be different to those for old sheeting types
(Engineer Grade, High Intensity and Diamond Grade).
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
4.1. Sheeting storage and handling
There are no changes in sheeting storage compared to older materials.
Storage should be in a cool, dry, indoor area, preferably at 18 – 240C and
30 – 50% relative humidity. Rolls should be stored horizontally in the
original package boxes on the shelves.
Partially used rolls should be replaced on original core supports in the
original package box and put back on shelves in storage. If there is no
original box, rolls should be supported by a pipe or rod through the core, as
stated before, in temperature and humidity controlled premises.
Cut sheets, should be stored in no more than 50 sheets piles, wrapped in
plastic and positioned horizontally on the shelves. In addition letters and
other symbols should be wrapped in plastic and put horizontally in boxes
for additional protection. In both cases temperature and humidity must be
controlled in the premises.
Whether the sheeting is packed in the original box or on the open roll, or
cut into sheets and symbols, it must be handled with care. Once damaged,
a prismatic sheeting surface can not be repaired. In this case even small
scratches can be visible during night performance of sign. This is because
of the high retroreflectivity of the undamaged surrounding surface.
4.2. Sheeting preparation
Sheeting preparation is the transformation of sheeting from roll to sheets,
ready to apply or screen print. Basically it should be a cutting operation but
there are some very important planning and sign designing phases to
prepare sheeting for cutting.
4.2.1. Planning of sheeting use
The first rule is never to mix different types of retroreflective sheeting on the
same sign. This means never to mix EGP, HIP or DG3 or classic EG with
EGP, HI with HIP and classic DG (VIP and LDP) with DG3 on the same
sign. The reason is due to their very different retroreflectivity. If materials
are mixed the night appearance of the sign will be very affected with darker
and lighter surfaces.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
When working with beaded types of sheeting the planning operations
priory to cutting were measuring and matching the sheeting. Matching the
sheeting was important only for large signs to achieve uniform color of the
sign (Figure 3 and 4).
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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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
When working with 3M prismatic sheeting there are two more very
important planning requests:
The first one is orientation of the sheeting (Figure 5). It is requested
for achieving uniform night appearance of the complete sign surface
with maximum retroreflectivity. This rule is dictated by the structure of
prismatic sheeting and geometry of prism reflectors.
The rule for EGP and HIP sheeting is that orientation of sheeting on
the sign must be 00 or 900 to achieve maximum retroreflectivity.
The rule for DG3 is that only 00 degrees provides 100% performance.
The 900 is also acceptable because it is 98%.
Other orientation angles are not recommended because they can
decrease the material performance.
Figure 5 – Orientation of the prismatic sheeting
The second rule is never to mix differently orientated pieces on the
same sign. This is valid for pieces of the same color between
themselves (background color sheets) and different colors
(background sheets and symbols). The reason is that differently
orientated sheets have different retroreflectivity which causes poor
night performance with darker and lighter areas on the sign. In Figure
6 is shown a simple example how pieces should be cut from
prismatic sheeting.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
Figure 6 – Planning the cutting of prismatic sheeting
(the simple frame has to be applied)
4.2.2. Cutting of sheeting
The new prismatic sheeting can be cut from both sides (face and liner side)
and this is the main difference to beaded sheeting (only from face).
The cutting methods are the same as for all other sheeting. Prismatic
sheeting can be:
♦
♦
♦
♦
♦
♦
hand cut by scalpel or scissors;
roll cut by special roll cut machine (slitter);
guillotine cut by manual or pneumatic guillotine;
die cut by the same tools and equipment as for beaded materials;
plotter cut;
laser cut.
Compared to old beaded materials, the only big difference is the plotter
cutting equipment and equipment settings for it. The results of testing with
the most frequent plotter cutter producers on European market are shown
in Table 1.
15
there is no device that
can cut new prismatic
sheeting
no suitable
models
Ioline
Panther
Vinyl Express
FC8000-130
there is no device that
can cut new prismatic
sheeting
no suitable
models
Mimaki
Graphtec
there is no device that
can cut new prismatic
sheeting
no suitable
models
- initial setting cutting
force settings 35
- initial setting speed 9
- 600 g of down force
- push roller kit OPH-A22
- knife CB15U-K30
- blade holder PHP32-CB15U
- two additional pinch wheels
- knife PLTB – Roland – 60
- knife holder model
PLTA-GRC-BLDHLD-HD
- knife down force
300mm
- 10000 mm/s speed
Summagraphics
- knife Z4
- knife holder C2 with gliding
disc
M - 800
M - 1200
M - 1600
- can cut only small
symbols and letters
- pinch wheels leave
marks
- can cut all colors and
shapes
- pinch wheels can
leave marks on the
sheeting
can cut all colors and
all dimensions and
shapes
can cut all colors and
all dimensions and
shapes
Zünd
Systemtechnik
- cutting pressure
1.4 – 2 bar
- 1000 mm/s speed
ARISTOMAT
SL1317
there is no device that
can cut new prismatic
sheeting
there is no device that
can cut new prismatic
sheeting
Notes
Aristo Graphic
Systeme
- knife 07132
- pneumatic head
- knife underlay 1mm grey
Recommended
settings
no suitable
models
no suitable
models
Roland Digital
Group
Cutting accessories
Mutoh
Model
Producer
Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
Table 1 – Plotter cutting of new prismatic sheeting
(recommended solutions on yellow background)
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
It is easy to conclude from the results in Table 1 that most of the plotter
cutters that were cutting beaded sheeting can not cut the new prismatic
materials. This does not mean that sign producers need to buy new
expensive equipment units since alternative methods of production exist.
Instead of cutting the symbols and letters from prismatic sheeting, only the
background color can be made from it. All other elements can be cut from
transparent ECF series 1170. A more detailed explanation of this method
will be given in the chapter 4.4. Here it is important to stress that this ECF
material can be cut on all types of plotter cutters with standard knifes.
Good results were achieved using a laser cutting device also. The cutting
shape was clean and precisely defined. Furthermore, the cut edge was
sealed by the laser heat and there was no need for edge sealer.
There were also some negative effects in laser cutting. On tested machine
it was not possible to adjust the cutting depth for kiss cutting in order to
avoid cutting all the way through the liner (it is highly possible that there are
more precise unit that can be adjusted). The laser beam was cutting
through the sheeting and liner all the time. In addition the sheeting area
near to the cutting edge (1-2 mm) becomes a little yellowish from the high
laser temperature (but it did not burn). This was visible only on close
inspection and did not affect the sign performances in any way.
4.3. Screen printing
When considering screen printing on new prismatic sheeting the most
important thing for sign producers is that the same equipment and screens
will be used as for the old beaded materials.
In addition, only 3M Scotchlite Process Color Series 880N is appropriate for
screen printing on the new prismatic sheeting. Any other inks can cause
the signs to fail in some way. 3M does not provide any more warranty for
3M Scotchlite Process Color Series 880 I
The tips on accessory materials for screen printing are listed below.
♦ proper printing ink are 3M series 880N only;
♦ proper thinners for ink series 880N is 711N or thinner/retarder
CGS-80 (up to 10%);
♦ when new, ink series 880N should not be thinned;
♦ the ink mixer should be with ink mixer on 1000-2000rpm;
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
♦ the coverage of ink series 880N is 25 - 30 m2/l;
♦ adding of other chemicals (retarder, hardener, etc.) to the ink series
880N is not recommended;
♦ in case of use 880N and not perfect temperature and humidity
conditions do not use CGS-80, only thinner 711 N is recommended;
♦ proper screen mesh is 61-64T monofilament polyester mesh only;
♦ mesh tension on the screen should be 16-18 N (1-2% mesh
stretching);
♦ screen developing emulsion must be water and solvent resistant of
the diazo or diazo-light type;
♦ the squeegee should be rubber, 1cm wide, rectangular, with 65 shore
hardness.
Drying notes
Type of
drying
Flow out
time1
Air
drying
during whole
drying time
Oven
drying
10 min
Conveyer
drying
1 min
Drying time Drying time
between
after final
colors
color
Other notes
- the distance between drying
3h (880N)
shelves minimum 5cm
2 h (880N)
- 0.5m/s permanent air flow
- the distance between drying
shelves minimum 5cm
30 min
30 min
- oven temperature 420C
- 0.5m/s permanent air flow in
oven
- the minimum length of drying tunnel is 10m
- parameters on testing: speed 3m/s, temperature 650C
- each producer has to find settings for his conveyer unit
Table 2 – Drying of ink series 880N on new prismatic sheeting
The other tips for proper screen printing on new prismatic sheeting are:
The ink mixing must be according to recommendation - with ink mixer
on 1000-2000 rpm, for at least 15 minutes and 1 hour resting before
starting to print. This is the only way that will provide a proper mix of
thinner, binder and pigment inside the ink.
The screen printing method is off-contact with fill and print pass.
Air drying must be in a well ventilated area with permanent air flow
over the prints. This prevents solvents from diffusing deep into the
1
The regular ventilators with at least 0.5 m/s air flow speed can be used. It is important
to obtain permanent air flow over all shelves on drying rack.
18
Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
top film of prismatic material. In addition it prevents later cracks on
printed areas. For all drying details see Table 2.
The ink series 880N could be oven and conveyer dried (see Table
2.).
4.4. Application of sheeting
When considering the application of sign faces from prismatic sheeting on
traffic signs there are two very different products:
♦ Standard traffic signs (police signs)
♦ Traffic guidance signs (large individually designed signs)
Besides the dimension of the sign, the production series (the number of the
same signs) are the main difference between these two groups. Because of
this, the application processes will be explained separately.
Table 3a – Laminator Adjustement Overview for Sign Sheeting Applications
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
4.4.1. Manufacturing of standard signs
The main characteristics of this sign type are the standardized, smaller size
and usually big production series. Because of this, standard signs are
usually produced by screen printing the sign faces followed by application
of the completed sign face.
Comparing to the application of sign faces from beaded materials, there are
not too many differences. Because of this the process will be described by
short notes only.
The conditions in the signshop application premises must be those
described in chapter 2. of this document.
The application substrates must be prepared as described in chapter
3. of this document.
The sheeting must be prepared as described in chapter 4.2. of this
document. The orientation rules (se chapter 4.2.1.) are obligatory in
the case of prismatic sheeting.
If prismatic sheeting has to be printed it must be done according to
the screen printing recommendations from chapter 4.3. of this
document.
Prior to application, the sheeting and blanks must be conditioned for
24 hours at room temperature (180 - 220C).
Application has to be done using the Squeeze Roll Applicator (SRA)
or Rolls Roller. If it has a pressure gauge the proper setting is 3.5 –
5.5 bar (350 – 550 kPa) depending on individual model. In case of
Rolls Roller the pressure should be closer to 5 – 5.5 bar. Too low
pressure can cause wrinkles or edge lifting. Too much pressure can
damage the micro prisms in the sheeting structure reducing the
retroreflectivity and can cause wrinkles.
The hand application using 5 cm hand roller (wider does not guaranty
proper pressure) or 3M PA-1G gold applicator with SA-1 low friction
sleeves is acceptable only for small symbols or letters. The hand
application with any other tools will not provide requested pressure *.
If it is necessary to apply two pieces of prismatic sheeting side by
side (splicing) this is allowed. In the case of prismatic sheeting
overlapping is prohibited because it can cause delaminating and
cracks in the sheeting. Only vertical direction of but splices is
permitted. This is to help removing the water from the sign face.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
Horizontal splicing is not recommended because it can cause ice
forming and delaminating on the traffic sign. The graphic
explanations for these rules are presented on figure 7.
Figure 7 – Recommended splices for prismatic sheeting
Only in the case of small series there is a recommendation to print
the sign frame and to apply a black symbol from some of the
following materials using application or transfer tape:
- 3M Application Tape SCPM-19 (provides rigidity when
liner is removed, not transparent)
- 3M Clear Transfer Tape TPM-5 (for use with ECF 1170)
- 3M Prespacing Tape SCPS-2
- 3M TFEC 260D lettering film (black)
- 3M ElectroCut Film Series 1178 (black)
- 3M Controltac Scotchcal Film 180-12 (black)
- 3M Scotchcal Film 70-12 (black) – acceptable only for
EGP; not recommended for durable HIP and DG3 signs
- 3M Scotchcal Film 50-12 (black) – acceptable only for
temporary signs with durability up to 5 years
- 3M Scotchcal Film 30-12 (black) – acceptable only for
temporary signs with durability up to 3 years
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
After removing the application, transfer or prespacing tape it is
necessary to re roll the sign through a Squeeze Roll Applicator or
Rolls Roller.
If it is necessary to cover the sign face with anti-graffiti protective film
the only proper product is 3M Premium Protective Overlay Film
Series 1160. Film series 1150 is not designed for prismatic sheeting.
4.4.2. Manufacturing of large signs
When considering the production of large guidance signs from prismatic
sheeting there are two methods.
The first one is traditional when all sign face elements are from the same
class of retroreflective material. It is the same method as described in
4.4.1. but with much larger pieces of sheeting. The downside of this
method is that for cutting the symbols and letters from prismatic sheeting
the producer will need one of the very expensive cutting plotters
recommended in table 1, chapter 4.2.2.
To help sign producers avoid the purchase of new expensive equipment
3M is offering another method that can be carried outh with classic
equipment pieces. In this case only the background of the sign is from
applied white prismatic sheeting and all other graphic elements are from
transparent, color EC Film Series 1170. This method will be explained step
by step with photographs in the following text:
The first step is computer designing of the traffic sign and cutting the
letters and symbols on a plotter cutter from 3M ElectroCut Film
Series 1170 (Figure 8). This film can be cut on all models of vinyl
plotter cutters. The cutting pressure is approximately 100g.
In the classic method of manufacturing guidance signs, the
background color could be blue, green or white depending on the
road class. In this new method, the background from retroreflective
sheeting is always in white! This makes for easier calculation of
retroreflective sheeting for demand and stock planning as well as
ordering (always white).
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
All other sign face elements will be cut from transparent ECF 1170.
This film is available in traffic sign yellow, orange, green, brown, red,
blue and black color.
Figure 8 – Plotter cutting the 3M ElectroCut Film Series 1170
Immediately after the cutting operation it is necessary to remove
excess film – weeding operation (Figure 9).
Figure 9 – Weeding operation on cut ECF 1170
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
To prepare ECF 1170 for application it is necessary to cover it with
3M Application Tape SCPM-19 or 3M Clear Transfer Tape TPM-5
from the face side (Figure 10)
Figure 10 – Applied application tape over ECF 1170
Figure 11 – Application of background white prismatic
retroreflective sheeting
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
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).
Squeeze Roll Applicator pressure setting should be 3.5 – 5.5 bar
(350 – 550 kPa) depending on individual model. In case of Rolls
Roller the pressure should be closer to 5 – 5.5 bar.
The blank type shown in the photograph requires application of the
sheeting over the profile edge. This is possible but the sheeting must
be softened using hot air fans mounted to blow before the edge
application rollers (Figure 11). If there are some cracks or
delaminating after the application, an additional pair of fans must be
positioned before the last pair of rollers.
The final number of fans and their exact position depends on the
blank type, roll applicator and used fans (subject to adjustment on the
spot by converter).
After the application of background white retroreflective prismatic
sheeting it is necessary to properly position previously prepared ECF
with application tape. After positioning it the application starts by
removing 5 – 10 cm of liner from the edge of the ECF (Figure 12).
Figure 12 – Positioning of ECF and initial removal of liner
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
The hand application of the edge follows (Figure 13). This will fix the
ECF and prepare it for application in the squeeze roll applicator.
Figure 13 - The hand application of ECF edge
Figure 14 – Puling back of ECF over the application roller
After fixing the edge, the profile with ECF should be inserted into the
roll applicator and ECF with application tape should be pulled back
and over the application roller (Figure 14). The guiding planks visible
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
on figure 14 are not obligatory. They are there to just help the
operator to control the application process.
The next step is complete removal of liner from the ECF (Figure 15).
Figure 15 – Removal of liner from ECF
Figure 16 – Application of ECF on prismatic sheeting background
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
The application of ECF on the background prismatic sheeting follows
(Figure 15). It is necessary to check (and if necessary re adjust)
pressure on the applicator because this time there is an additional
film sheet over the blank and sheeting. The heating fans in the
photograph are switched off.
The ECF is applied and the application tape can be removed (Figure
17)
If there are some additional symbols in different colors they have to
be applied separately. It is necessary to cut them first from ECF in
the required color. After that they have to be prepared by the weeding
operation and by applying the application, transfer or prespacing
tape. Finally they can be hand applied (Figure 18) or squeeze roll
applied (Figure 19). After that the application tape can be removed.
After removing all the transfer or application tape the complete
surface must be re-rolled in a squeeze roll applicator. The other
option is to apply transparent anti-graffiti 3M Premium Protective
Overlay Film Series 1160 during re-rolling (Figure 20).
Figure 17 – Removal of the application tape
The last tip on ECF 1170 concerns the splices. If it is necessary to
apply two pieces of ECF of the same color, side by side, both splicing
methods are acceptable (overlap and but splice). The but splice
should be vertical on the sign face. The overlapping splice should be
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
horizontal with an overlap of approximately 3 mm. Looking the
erected sign in vertical plane the overlapped film should be on the
lower side of the sign and overlapping on the upper.
Figure 18 – Hand application of small symbols in different colors
Figure 19 –Application of additional symbols by a squeeze roll applicator
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
Figure 20 – Application of transparent anti-graffiti protective film
Figure 21 – A finished guidance traffic sign
from the new prismatic retroreflective sheeting in a white color
using ECF series 1170 in blue, green, red and black color
and covered with transparent protective film 1160
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
5. Packing and storage of finished traffic signs
First of all it is important to be careful when handling the finished signs to
avoid any post manufacturing damage.
Prior to any kind of packing, all sign faces from prismatic sheeting must be
covered with 3M Scotchlite slipsheeting SCW-568 or with liner from EG,
HIP, DG3 or FDG3 sheeting (glossy side against the face).
After that, signs can be packed in pairs, face to face with plastic bubble
pack or individually in some paper, cardboard or plastic covers. Plastic
bubble pack is necessary to avoid any chance of damaging the prismatic
cells. These cells are stronger than encapsulated ones but can be
damaged any way, and due to high glare and retroreflectivity the damage is
much more visible.
Finished signs should be stored indoors, face to face on edge, on wooden
battens (to prevent edge damage). Wooden battens should be constructed
in such way that they will permit free air circulation and normal moisture
evaporation. If this is not possible and signs have to be stored outdoor it is
necessary to remove all packing material including slipsheeting so that
nothing is in contact with the sign face. In this case the wooden battens
must provide at least a 5 cm gap between sign faces. In addition to this, if
the signs have to be stored in metal containers the procedure has to be the
same as for outdoors.
Additional recommendations are to avoid bending, crating or stacking in a
manner which puts finished signs under pressure. Further more it is not
recommended to put signs face down or to lay objects against sign face.
Finally, if packed signs get wet it is necessary to remove packaging, dry the
signs, pack them in new dry material and store them in dry conditions. If
there is a chance that they will become wet again it is recommended not to
pack them and to use the outdoor storage procedure.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
6. Trouble shooting guide
6.1. For handling prismatic sheeting
CONDITION
POSSIBLE CAUSES
CORECTIVE STEPS
1. Sheets do not lay
flat in a stack.
Excessive moisture absorption Stock materials in an
or loss
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. Contamination - test by
spraying or sprinkling water on
the sign blank. If it beads up
rather than flowing out evenly
on the surface, the blank may
have oil or wax on it.
Blanks should be properly
prepared as stated in Chapter 3.
B. Sign blank dusty of “gritty”
Use a “tack” rag to wipe the
surface, then solvent wipe with
ethylated spirits.
C. Sign blank not properly
prepared. The surface may be
too smooth to permit proper
adhesion, or may have loose
phosphate of chromate
conversion coating. Painted
surfaces may be
contaminated with waxes,
silicone or other agents.
Blanks should be properly
prepared as stated in Chapter 3.
A. Sign blanks have been
solvent wiped: solvent has not
completely evaporated.
Sign blanks must be thoroughly
dry.
B. Painted surfaces not
completely dry: escaping
solvent causes bubbling.
Paint must be completely dry
before application. Bake surface
if possible.
3. Sheeting bubbles
during application
Aluminum must be etched
scrubbed using a 3M ScotchBrite scouring pad or steel wool
and abrasive cleaner.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
C. Moist sign blanks.
Blanks must be thoroughly dry.
If sign blanks 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.
D. Process color not
thoroughly dry: solvent is
causing adhesive to
preadhere.
Thoroughly dry processed faces
and emblems before application.
4. Wrinkles in applied A. Unapplied faces may
sheeting.
become wavy if exposed to
extensive moisture during
shipment or storage.
B. Air between sheeting and
blank
See item 1, under CONDITION
above.
Check roll applicator adjustment
and application procedure
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
6. Trouble shooting guide
6.2. For screen printing on prismatic sheeting
CONDITION
1. Incomplete
coverage of Series
880 I Colors (spots
where ink does not
flow out properly).
POSSIBLE CAUSES
A. Be sure all equipment and
work area is free of
contaminants: contaminated
sheets, colors, screen or
atmosphere.
CORRECTIVE STEPS
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 the shop is using any of
the temporary films with soft,
oozy adhesive, 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
stock conditioning area
separate from any equipment
that uses large amounts of
lubricant (e.g. vacuum
applicators, which use oil).
5. Use new wiping rags and if
re-used by the screen shop,
have them laundered
separately from other rags and
clothing. Re-laundered rags
used by other industries may
often retain some silicone or oil
contaminants.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
6. Ensure that color and thinner
are thoroughly mixed and
strained. Mix with a high speed
mixer.
7. Avoid as much as possible,
touching a sheet in the area to
be screened. Handle sheets
only in their waste edge area. It
may be helpful to wear clean
cotton gloves during cutting or
handling operations.
8. Tack rag each sheet lightly
just before screening.
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 colors.
A. Colors 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.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
4. Ink bubbles
excessively:
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.
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 colors.
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.
Bubbles are caused by such
things as:
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*.
*
NOTE: If bubbles occur during screening, a strong air flow on processed areas can
dry the bubbles quickly and prevent them from flowing out properly. To avoid this
situation, switch to a slower speed on the fans or increase the distance of the fans from
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 colors dry.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
5. Orange peel
(small uniform
scaling patterns).
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.
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:
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 for ink series 880I.
A. Ink too thick
Remix with more thinner.
B. Ink not thoroughly mixed.
Mix thoroughly
C. Wrong thinner.
Use only recommended
thinner.
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.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
A. Ink too thick.
Remix with more thinner.
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.
E. Wrong thinner.
Use only recommended
thinner.
8. Ink cobwebs at
copy edges
Static electricity.
Ground the table, screen and
sheeting with rope tinsel and/or
increase shop humidity.
9. Excessive dust
pick-up.
Airborne dust and lint
attracted by static electricity.
Seal floors, keep floors and
work area clean. Ground the
table, drying rack and if
necessary screened sheeting
with rope tinsel and/or increase
shop humidity.
10. Streaks or marks
in the screened
area.
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
more thinner.
D. Nick in squeegee.
Check squeegee blade and
sharpen or replace rubber if
necessary.
7. Ink drying in
screen.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
11. Blurred edges on
screened area.
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.
A. Ink too thin, and runs under
the stencil edges.
Remix with 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.
13. Cracks in the
screened are:
A. Concentration of solvent
vapors between shelves on
the drying rack retards 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, increase
temperature or oven dry if
equipment is available.
C. Using coarse mesh screen.
Use recommended screen
mesh.
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
drying shelf.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
4. Use every second drying
shelve.
B. Insufficient exhaust air flow
in drying area.
Improve exhaust to remove
solvent from drying area.
C. High humidity or low
temperature.
1. Start dehumidification.
2. Install heater.
D. Rough handling of
sheeting.
1. When drying unapplied
sheeting use a smooth
cardboard underline on drying
shelves for uniform support.
2. Avoid stretching sheeting
during application.
3. Do not flex or bend when the
ink is wet.
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.
Roll set remains in sheets.
Roll sheets gently against curl
or stack sheets in pack
overnight.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
6. Trouble shooting guide
6.3. For handling finished signs and sign faces
CONDITION
1. Processed sheets
block together in
stacks
POSSIBLE CAUSES
CORECTIVE STEPS
A. Final color not thoroughly
dry.
Color 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 slipsheeting.
2. Surface
impressions on
processed sheets.
A. Final color not dry.
Check drying before stacking.
B. Stack under pressure or
stack processed sheets in the
presence of excessive heat.
Avoid exposing stacks to
pressure or excessive direct
heat.
3. Finished signs
stick together.
Signs were stacked flat with
slipsheet - heavy stack
pressure causes blocking.
Store signs on edge, with
spaces between signs and
slipsheet.
4. Stored signs show
dark spots or
blotches on face.
A. Signs stored in a damp
area or on damp surface with
pressure on the sign face.
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 with slipsheets are in
contact with the sign face.
Signs that become wet in
storage should be unpacked
and stored as above.
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Permanent Signs Production Manual – Quality with 3MTM Prismatic Sheeting Series
5. Unapplied faces
wrinkle and
separate from
liner.
Face incorrectly rolled (inner
side out).
If sheets must be rolled for
shipment, roll face side out
around a core with a minimum
8,3cm diameter, or ship
emblems packed flat in their
crates.
6. Cracked edges on
emblems.
A. Emblems packed loosely in
shipping container.
Emblems must be packaged to
prevent movement within
shipping container.
B. Using dull cutting tool.
All cutting tools must be sharp.
Faces bent too sharp.
Faces must be handled
carefully.
7. Cracks in un
mounted faces.
42