Product Handling

The Dow Chemical Company

Packaging and Converting

July 2011
Product Handling

o Storage

o Mixing

o Filtering

o Pumping

o Pot life

o Disposal

o Shelf life/Storage life

o Viscosity control

o Coat weight control

o Recirculation

o Blend off

o Clean-up
Storage

• Protect against exposure to moisture

– for isocyanate cure systems

• Drying tubes

• Replace contents with dry gas

• Avoid temperature extremes

• Refer to technical data sheet for specific 

products
Desiccant tubes

• For use with moisturesensitive coreactants 

(such as Co-F or Co-CT)

• Used to dry the make-up 

air when coreactant is 

drawn from a drum

• The pictured drier can be 

unloaded and the 

desiccant regenerated

• Single-use cartridges are 

available

Image drawn from: www.drierite.com/catalog3/page6.cfm
Dispensing drum rack

• Set-up for dispensing adhesive 

and coreactant from drums

• High usage rate

• Drums on drum rack

• Top drums feed the lower set of 

drums

• When top is empty, take off and 

replace

• Note desiccant drying tubes on 

both adhesive and coreactant

• Can be fed into a 

meter/mix/dispense unit

Image from: http://www.sealantequipment.com/materialpumps.htm
Shelf life/Storage life

• Shelf life - The length of time that a sealed container 

of product stored under specified conditions will 

remain suitable for use.

• Use adhesive within recommended shelf life.

• Six months from date of receipt is default.

• See Data sheet for variances.
Mixing

• Weighing – Best practice is to mix on a 

weight basis

• Diluents

– Urethane grade solvents for all urethane 

curing systems

– less than 0.05 % water, and less than 0.5 

% alcohol
Center Mixing Off-Center Mixing
Mixing?
Mixing Equipment

• Portable mixer

http://www.premiermill.com/literature/premier/PDF/pm-usf_unimixstand_pm.pdf
Mixing Equipment

• Floor-Standing Mixer

High speed mixer from Charles Ross and Sons
Weighing/Tolerances

• Mix Ratio should be  10%of TDS.

– 100/13 = 100/11.7 to 100/14.3

• A floor balance that is  2 lb is fine for weighing 

100 lb of A component ( 2%).

• Not good for weighing 10 lb of coreactant (

20% mix error).

• Weigh coreactant in small pail on a more 

accurate balance and rinse into A component 

using part of dilution solvent.
Batch Size Considerations

• Size of mixing equipment -

– match mixer to size of vessel.

• How much you intend to use -

– Generally not recommended to make up 

more than 8 hours worth to be safest.

• Pot life consideration

• Depends on ambient conditions, type of 

chemistry and cleanliness of solvents. 
Mix Ratio

• Technical data sheet information

• Adhesive/coreactant ratio

±10% of target

• Weight/weight basis

– Preferred for process control

• Volume basis

– Not recommended, likely to produce mixing errors
Mix Ratio

• Example:

 Adcote 555 adhesive

 Adcote 536B 

coreactant

 An accounting 

exercise
Mix Ratio

• Definitions

 NV, NVM = “non-volatile” and “non-volatile material” (also 

known as % solids)

 Ethyl acetate = EtOAc

 TDS info:

Adcote 555 = 70% solids (NVM)

Adcote 536B = 75% solids (NVM)

100:13 TDS mix ratio, wet/wet on a weight basis

“Wet/wet on a weight basis” means “as received” (out of the drum, 

pail or bucket)
TDS Information for Adcote 555/536B

Adcote 555 Solids 70% (%NV), Weight/Gallon 8.5 lb

Adcote 536B Solids 75% (%NV), Weight/Gallon 9.4 lb

EtOAc = 7.4 pound per gallon (from any reference source)

Mix ratio = 100:13

Goal is to create a recipe at (as an example) 40% solids

Build an “accounting” table
Mix Recipe Table

Material Weight %NV NVM wt Pounds per gallon Gallons

Adcote 555 100.0 70% 70.0 8.5

Adcote 536B 13.0 75% 9.8 9.4

Ethyl Acetate 7.4

Total

1) From TDS, enter %NV and pounds per gallon of each 

component (ethyl acetate data can be found in a number of 

sources)

2) Mix ratio is 100:13. Enter “100” and “13” respectively.

3) Multiply 100 by 70% solids to determine the nonvolatile weight 

of Adcote 555. (100) x (0.70) = 70.0

4) Multiply 13 by 75% solids to determine the nonvolatile weight 

of Adcote 555. (13) x (0.75) = 9.75  9.8
Mix Recipe (con’t)

4) Total the NVM weight column

70 + 9.8 = 79.8

5) Divide total of “NVM weight” column by 40% solids to 

determine the total batch weight. Enter in Weight column as the 

batch total weight

79.8  0.40 (40%) = 199.5

6) Subtract Adcote 555 and Adcote 536B weight from Total 

Weight amount. This difference is the amount of EtOAc to add. 

Enter in the table.

199.5 – (100.0 + 13.0) = 86.5

Material Weight %NV NVM wt Pounds per gallon Gallons

Adcote 555 100.0 70% 70.0 8.5

Adcote 536B 13.0 75% 9.8 9.4

EtOAc 86.5 7.4

Total 199.5 79.8
Mix Recipe Table

Material Weight NVM wt %NV

Parts per 

Hundred

Pounds 

per gallon Gallons

Adcote 555 100.0 70 70% 50.1 8.5

Adcote 536B 13.0 9.8 75% 6.5 9.4

EtOAc 86.5 43.4 7.4

Total 199.5 79.8 100.0

7) Divide each component weight by (total weight  100) to 

get parts per hundred (Per cent)

199.5  100 = 1.995

100  1.995 = 50.1 (Adcote 555)

13  1.995 = 6.5 (Adcote 536B)

86.5  1.995 = 43.4 (EtOAc)

8) Total should be 100.0 (if not, check for errors)

9) This is the % recipe – use this for volume and cylinder 

calculations later
Mix Ratio

• Calculate volume from % recipe

– Now in a per cent basis

 50.1  8.5 = 5.9 gal Adcote 555

 6.5  9.4 = 0.7 gal Adcote 536B

 43.4  7.4 = 5.9 gal EtOAc

 Total 100.0 pounds adhesive

 Total = 12.5 gal mixed adhesive

100/12.5 = 8.0 pounds per gallon mixed adhesive 

density (save for later)

Material Weight NVM wt %NV

Parts per 

Hundred

Pounds 

per gallon Gallons

Adcote 555 100.0 70 70% 50.1 8.5 5.9

Adcote 536B 13.0 9.8 75% 6.5 9.4 0.7

Ethyl Acetate 86.5 43.4 7.4 5.9

Total 199.5 79.8 100.0 12.5
Mix Ratio

• Systematic approach for mix calculation

• Accounts for raw material inputs

• Mass balance

• Proper mixing and handling

• Optimum adhesive performance
Area Calculation

• How much adhesive is 

needed to laminate a 

given job?
Area Calculation

• Area calculations

• Need web width and 

length

• Need application 

weight

• Example:

 2.5 million foot job

 52 inches wide

 1.5 pounds per ream
Area Calculation

• 2,500,000 ft length x (52 in/12 in per foot) 

= 10.8 million ft2 area

= 10.8 x 106ft2

• Ream = 3000 ft2

• 10.8 x 106ft2  3000 ft2 per ream = 3600 

reams
Area Calculation

• 3600 reams x 1.5 pounds per ream = 5400 

pounds of DRY mixed adhesive

• 5400 pounds  0.40 (40% solids) = 13,500 

pounds of LIQUID mixed adhesive
Area Calculation

• From the recipe (pph) we can calculate:

– 50.1% of the mixed adhesive is Adcote 555

• (13500) x (0.501) = 6764 pounds Adcote 555

– 6.5% is Adcote 536B

• (13500) x (0.065) = 878 pounds Adcote 536B

– 43.3% of the mixed adhesive is ethyl acetate

• (13500) x (0.434) = 5846 pounds ethyl acetate

Material Weight NVM wt %NV

Parts per 

Hundred

Pounds 

per gallon Gallons

Adcote 555 100.0 70 70% 50.1 8.5 5.9

Adcote 536B 13.0 9.8 75% 6.5 9.4 0.7

Ethyl Acetate 86.5 43.4 7.4 5.9

Total 199.5 79.8 100.0 12.5
Area Calculation

• How much to make?

• How much to use?

• Enough inventory for the job

• Can be used for cost calculations
Mixing

• Pre-mix minimum of 15 minutes

• Size blade to size of container

• Mild Vortex, avoid entrapping air

• Move material off bottom of drum

• Continuous gentle mixing 
Top-down Mixing

Animations courtesy of Dr. Thomas A. Post, Post Mixing Optimization and Solutions
Bottom-up Mixing

Animations courtesy of Dr. Thomas A. Post, Post Mixing Optimization and Solutions
Floor Balance

• Used to weigh out 

coreactant

• Tare container, fill and drain, 

tare again

• Provides a better “drain” tare 

than empty container alone

• Weigh and add using weight 

difference

Image from: http://us.mt.com/us/en/home/products/Industrial_Weighing_Solutions.html

Viscosity Control

• Viscosity - A measure of a fluid’s resistance to 

flow. 

• Flow behavior is an indication of process ability. 

• Establish the appropriate viscosity to maximize 

the quality and consistency of the adhesive 

application.

• Take measures to prevent/limit solvent loss.
Brookfield Viscosity

• In the lab a Brookfield Viscometer can 

measure viscosity more consistently and 

accurately than Zahn Cups.

Brookfield Viscometer
Efflux Cup Viscosity

• Inspect cup for damage.

• Stir solution thoroughly, 

but avoid entrapping air.

• Limit solvent loss.

• Immerse Cup completely 

to below surface of 

liquid.

Shell cup

Zahn cup
Zahn Cup Viscosity

• Lift the cup crisply, keeping the handle 

vertical.

• Start timer when top of cup breaks surface of 

liquid.

• Hold cup about 6 inches above surface.

• Stop timer when stream first breaks.
Coating Weight Control

• Appropriate weight to achieve desired 

performance and appearance.

• Inadequate and/or inconsistent coating 

weights are often source of problems.

• Monitor Coat Weight and Viscosity.
Recommended Coating Weights

Solventless: 0.8 - 1.3 lb/ream (1.3-2.1 g/m2)

Water-based: 1.5 lb/ream (2.5 g/m2)

Solvent-based: 1.75 - 3.0 lb/ream (2.9-5.0 g/m2 )

Heat seal coatings: 

3.5-4.5 lb/ream (5.7-7.3 g/m2 )

Primers: 0.5-1 lb/ream (0.8 - 1.6 g/m2 )
Monitor Coat Weight and Viscosity 

Increasing Viscosity Means

• If coat weight is gradually increasing solvent is 

being lost.

• Adjust viscosity with appropriate solvent, 

Recheck coat weight.

• If coat weight is not increasing pot life is 

reaching its end.

• Consider making up new adhesive batch.
Factors Reducing Pot Life

• High Humidity

• High Temperature

• Moisture in Solvents

• Moisture in Adhesive
Pumping

• Application

– Feed from drum to sump 

– Feed from sump to applicator

• Types

– Diaphragm

– Peristaltic

– Centrifugal

– Positive displacement (Bran & Luebe)
Diaphragm Pump

• Diaphragm pumps are very 

common and come in many 

sizes.

• The pumps operate 

continuously but have a safety 

valve which returns fluid to the 

input side of the pump if 

pressure rises above a set level.
Double Diaphragm Pump

• Simple valve system to move 

the DIAPHRAGM ROD. 

• The PILOT SPOOL is pushed 

back and forth allowing air to 

move the Air Distribution 

Valve back and forth.

The AIR DISTRIBUTION ROD 

controls air flow to the left or 

right air chamber, reversing 

on each stroke. 

The four BALL VALVES are freefloating and operated by 

pressure differences in the 

pumped liquid.. Liquid flow is 

from the bottom to the top.
Peristaltic Pump
Peristaltic Pump

• In this example three 

rollers on rotating arms 

pinch the tube against an 

arc and move the fluid 

along.

• One of the main 

advantages - Cleanliness.
Disc Pump
Centrifugal Sump 

Pump
Sump or Reservoir

Images drawn from www.indco.com
Recirculation

• Minimize foam generation

– Keep return distance short

– Return to bottom of sump, below fluid level

– Keep return as far from intake as possible

– Keep sump as full as possible

• Cover to minimize solvent loss.
Filtering

• A filter in the return line is recommended to 

remove debris, trapped foam etc.

• Simple as cheese cloth.

• Elaborate cartridge systems.

• Magnetic particle filter.

Clean-up

• Short breaks 

– Solventless: Dump adhesive and wipe 

rolls with solvent.

– Solvent-based: Keep cylinder wetted 

with adhesive. Prevent solvent loss.

– Water-based: Keep cylinder wetted with 

adhesive. Prevent skinning.

• Clean the smoothing bar each & every 

time the line stops.
Blend-off

• Generally discouraged. Never blend-off 

solventless mixes.

• Blend older mixes, such as those held 

overnight, at 10-20% level with fresh mixes. 

Adjust the viscosity as needed.
Disposal

• Contact your local EPA for specific regulations.

• Refer to the MSDS regarding precautions or 

protective equipment in the event of a spill.
Good Product Handling

•Important For Consistent Results

–Weighing

–Mixing Practices

–Coat Weight Control