moulds plus effective color changes

8/8/2019 Moulds Plus Effective Color Changes

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Presented by


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Know Your Process

Polymer flow & color type

Melt viscosity

Process set-up for fast color change

s ng ra urge or as co or c ange

A Systems Approach!


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Pigments

Colorin Materials

- -Discrete particles Liquids


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How Different Pigments Work

0,01m 0,1m 1m 10 m 100 m

Fillers

Inorganic PigmentsMetal/Pearl lustre pigments

Platelet structure

Titanium Oxide

Organic PigmentsCarbon Black

Interference PigmentsReflection PigmentsAbsorption Pigments


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Non-Effect Pigments: PARTICLE SIZE

MINERALORGANIC

0.5-1m0.01-0.1m

-+Specific surface area

=Area in contact with polymer


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MINERALORGANIC

0.01-0.1m

0.5-1m

Specific surface area

- +

Area in contact with polymer

EasierHarder Dispersability

mixing

sufficient


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MINERALORGANIC

Mixing Requirements


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Physics of Polymer Flow

Velocity & Shear Rate

r

v

dr=

Re = V D


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Velocity near 0 at melt channel wall

v

Plastic pulled from melt channel

Boundary Layer from a Color Change


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Molding System Considerations

Screw/Barrel:- Good mixing capability

Resin Conveying:- Easy/fast cleaning

Hot Runner:- Reduced hot runner

Color Dosing:- Easy/fast cleaning

-- No mismatches (nozzle)- No hang-up spots

(check valve)

- -- No-mismatches- No hang-up spots- Uniform thermal profile- Mixing capability

- -- Repeatable dosing


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Best Design Practices for Hot Runners

Manifold Bushings Channel mismatches

Valve Gate

Fit in manifold

Stem guidance

Manifold

Tip insulator

Manifold/Nozzle Interface Avoid channel

mismatches

Channel layout Thermal uniformity Residence time

Hot Tip Gate Area

Sprue Bushing/Sprue Bar Channel size changes

(Tapers, etc.) Thermal rofile

Plugs Blended plugs


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Melt Channel Sizing


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Why Thermal Uniformity Matters

Cooler Area

Hotter Area

Removed melt channel


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COLD AREA IN A HOT AREA IN A

A B

A B

Boundary Layer vs. Thermal Profile


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Elimination of Cold Areas

Melt channel

Overall T = 30CT = +17C

T = -13C

pt m ze emperature ro e


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Color Change Planning Not Optimized

250 shots 150 shots 150 shots 50 shots

Resin used: 57.6kg

Note: 32-drop mold

3gram part


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Color Change Planning - Optimized

s o s s o s s o s s o s

Total # of shots: 400 shots

Resin used: 38.4kg 33% reduction in resin usage

Note: 32-drop mold

3gram part


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Purge Compounds Can Improve Color Change

450

350

400

200

250

#o

fshots

80% reduction

100

150

0

Valve Gate HR (without Purge Compound) Valve Gate HR (with Purge Compound)


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Purging Process Analysis

wo s gn cant costs are generate w en purg ng:

Scrap: Amount of resin and purging compound usedo c ean e mac ne

Downtime: Amount of time used to purge/clean the.

Lost of production

Manpower


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Scrap

component of the purging costbut it is definitely the mostvisible.

Many companies monitor this

production.

Reducin scra durin a color

change can only be achievedby using a purging compound.


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Down Time

component of the purging costwhen analyzing the purgingprocess.

Fast purging means gaining

reducing the cost of energy andmanpower.

Purging compound are designed toreduce down time making color

.


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Cost Efficiency

Usin Ultra Pur e will ield the followinresults:

Reduce scrap production by 50 to 80%

Reduce downtime by 60 to 85%


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Quality

Using Ultra Purge:

will reduce the rejects due to black.

will eliminate 100% of all remnants of

color and resin that can otentiallgenerate black specks or colorstreaking during production.

w remove car on epos ts generatefrom thermo-sensitive resins.


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What is Ultra Purge

When to use Ultra Purge

Wh use Ultra Pur e

Ultra Purge Benefits

Product Line

Purging Procedures


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What is Ultra Purge

Ultra Purge is a chemicalPurging Compound in a

- -pellet form.

It is designed to cleanscrews, barrels, shootingpots and hot runners whenchan in color or removin

carbon contaminations.


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How Ultra Purge Works

Ultra Purge is nonabrasive and works through a chemicalreaction. With the presence of a chemical component, colorncrus a on, ac spec s an rus are so ene , remove anejected from machines

An ex andin a ent is added to Ultra Pur e which allows thecompound to be more efficient - even in hard to clean situations

Ultra Purge cleans at the processing temperature of the


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Molecule of HDPE with red color

Ultra Purge


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Temperature: Effect on Viscosity

Cooler Melt Hotter Melt

Higher Temperature =Lower viscosity resin

350FHigher temperature =Lower viscosity resin

450F

450F 350F

Lower temperature =Higher viscosity resin

Lower temperature =Higher viscosity resin


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For Use With:

Ultra Purge is designed to be used with all thermoplasticresins in:

Injection Molding Machines (all types and sizes)

Hot Runner S stems

Injection Blow Molding Machines

Com ression Moldin Machines


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Why use Ultra Purge

to save money by reducing downtime and scrap materialwhen changing color. Improvement of 50 to 80% scrap

to improve the quality of production by removing black

specks to make start-up time faster

to eliminate slip screw problems

to preserve equipment from steel oxidation


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Cost Analysis PE Application

Colorant Used Red (liquid)

Resin Ultra Purge

Lbs of PE Lbs 100 6Cost of PE USD/Lb 0.65 0.65

Lbs of Ultra Purge P-O Lbs 7Cost of Ultra Purge P-O USD/Lb 6.00

. .

Time required for purging hr 3 0.5Down-Time/Lost Production Hourly Cost USD 150 150

Total Down-Time Cost USD 450 75

Total Cost per Purging USD 515.00 120.90

Purge

394.10


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Ultra Purge Benefits

Ver efficient in cleanin rocess

Moldable purging compound Cost effective (small quantities are needed - plastic processors

Easy to be removed from the machine

All Ultra Purge grades are food contact certified by EU and FDAregulation

100% safe. All ingredients are GRAS from the FDA assubstances added indirectl to human food

Easy to use

Odorless -does not produce dangerous gases


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Ultra Purge Product Line

- -

Ultra Purge P-OH 338-572F 170-300C

Ultra Purge PO-C Concentrate 374-608F 190-320C

Ultra Purge BP Concentrate 338-572F 170-300C

Ultra Purge High-E 374-608F 190-320C

Ultra Purge Low-E 284-500F 140-260C

Ultra Purge HT 555-750F 290-400C - - -

Ultra Purge PET-C 374-608F 190-320C

Ultra Purge 9010 Concentrate 284-608F 140-320C

Ultra Pur e CE-E Concentrate 284-500F 140-260C

Ultra Purge PLUS 374-608F 190-320C Ultra Purge 5060 374-608F 190-320C

Ultra Purge 5050 374-650F 190-343C


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Purging Procedures

Screw and Barrel


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STEP 1

Keep the barrel of the press full of the resin/color you want to purge when addingthe Ultra Purge to the machine (we recommend loading one barrel full of Ultra Purgefor machines that are in good working condition)


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STEP 2

Adjust the screw back-pressure to allow the loading of Ultra Purge (generally 20 to 30 psi)*For larger machines (over 200Ton), we recommend reducing the shot size to 10-15% of the maximum shot size


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STEP 3


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STEP 4

When the previously loaded quantity of Ultra Purge is used up, load machine with the next productionmaterial. It is important not to run the barrel empty to improve the performance of Ultra Purge.

Continue running the machine for a total of 4-5 full shots to eliminate remnants of Ultra Purge within themachine.

Begin normal production.


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Pictures


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Purging Procedures

Hot Runners


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STEP 1

Increase the temperature of the hot runners in all zones by 30 to 40F. (20 to 30C)

Follow steps 1 and 2 for the injection molding purging procedures that were previously stated.

when adding the Ultra Purge to the machine


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STEP 2

Start to make injections through the hot runners with the mold closed or opened (we suggest to keepthe mold open if the molded part is difficult to be ejected from the mold).

a e ree n ec ons roug e o runners en a ow or a m nu es soa me.


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STEP 3

Continue molding until the molded parts appear visibly clean (we suggest to perform at least 4injections).

oa neu ra or pro uc on ma er a o e m na e e remnan s o ra urge w n e mac ne. Begin normal production.


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CLOSURES

Sequence of shots from red to natural molding Ultra Purge


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Bubbles


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Solidified Layer in Tip Slows Color Change

Reduced

LargeGate Bubble


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Using Tip Insulators Improves Color Change

1000

800

900

500

600

f

shots

200

300

400#

0

100


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Cavity Filling During Color Change

Red color from cooler bubble

first in = first freeze


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W t h f Mi t h


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Watch for Mismatches

Sprue Bushing Machine Nozzle

Not O timized

Machine-Nozzle/Sprue Mismatch

Optimized

P i P d


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Purging Procedures

Extruders

STEP 1


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STEP 1

If a screen pack is present, please remove it from the machine Keep the barrel of the machine full of the resin/color you want to purge when

adding the Ultra Purge. Run the machine at the same temperature as the previouspro uc on ma er a we recommen oa ng e arre w ra urge a w ce eamount of the barrel size for machines that are in good working condition)

STEP 2


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STEP 2

Adjust screw rotation to low to allow the compound to expand inside the machine. Theejected purging compound should have a foamy appearance. If it does not, furtherreduce the screw rotation speed.

For larger extruders, allow Ultra Purge to soak for 3 minutes once it begins to eject out of the machine

STEP 3


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STEP 3

When the Ultra Purge is extruded from the machine, load machine with the newproduction material and flush out any remnants of contamination. It is important notto run the barrel empty to maximize the performance of Ultra Purge

Begin normal production


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For more information please contact us

Moulds Plus International s.r.l.

Via D. Carbone, 104 - Villalvernia (AL) - 15050 ITALYTel +39 0131 83140 Fax +39 0131 836 882

Moulds Plus International USA, Inc.

1521 E McFadden Ave Unit G, Santa Ana, CA 92705 - USA

Tel (714) 708-2663 Fax (714) 708-2659

Moulds Plus Mexico SA. de CV.

Ahorro Postal 103 Col. Miguel Aleman

Del. Benito Juarez CP 03420

Mexico D.F.

Tel (55) 8590-8834

www.ultrapurge.com [email protected]

Summary


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Summary

Pigment selection and processing have a direct impact on color

change time

factors:

Melt channel layout and sizes

Elimination of hang up spots

Improved melt mixing in machine & hot runner can make a

Conclusion


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Conclusion

To master color change:

Know your resin (e.g., viscosity behavior)

Know your colorant (e.g., mineral vs. organic, mixing requirements)

Select/configure equipment appropriately (e.g. easy to clean, no

hang-ups, optimized hot runner design) Use mixing to disperse color (M/C nozzle, hot runner nozzle tip)

Use purging compound as required

A l a roven color chan e rocedure


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