Critical Properties of PVC Raw Materials

 

Canadian General Tower

CRITICAL PROPERTIES OF RAW MATERIALS
 



INTRODUCTION

AS CAN BE READILY APPRECIATED, THIS TOPIC IS FAR RANGING AND VERY COMPLICATED, A FULL DAY SEMINAR COULD BE SPENT ON EACH MATERIAL CATEGORY, WHAT WE WILL ATTEMPT, AT THIS TIME, IS A PRESENTATION OF A VERY GENERAL NATURE CONCERNING THE CHARACTERISTICS DEEMED IMPORTANT IN THE VARIOUS RAW MATERIAL TYPES AS THEY PERTAIN TO P.V.C. MANUFACTURE AT CGT.

WHAT WE WILL BE EXAMINING IS NOT THE PROPERTY RESULTING FROM A MATERIAL BEING USED BUT THE PROPERTIES INHERENT IN THE MATERIAL AS IT IS PURCHASED.

WITH GENERALIZATION A MEASURE OF SIMPLIFICATION OCCURS. WITH SIMPLIFICATION THE POSSIBILITY OF OMISSIONS AND SOME DISTORTION CAN ALSO OCCUR. WHERE THIS MIGHT HAPPEN, DURING Carl, FOLLOWING REMARKS, YOUR UNDERSTANDING IS ASKED FOR.
 

DISCUSSION

THE RAW MATERIAL CATEGORIES USED AT CGT CAN BE LISTED AS FOLLOWS-.

  • PVC RESINS
  • PLASTICIZERS
  • FILLERS
  • LUBRICANTS
  • PROCESSING AIDS
  • STABILIZERS - HEAT & LIGHT
  • FIRE RETARDANTS
  • ANTIMICROBIAL AGENTS
  • SOLVENTS
  • COLORANTS
  • BLOWING AGENTS
     

NOW EACH OF THESE MATERIAL GROUPINGS HAS A DISTINCTIVE FUNCTION IN THE MANUFACTURE OF A P.V.C. PRODUCT. ONE GROUP MAY AFFECT PRIMARILY END USE PROPERTIES. ANOTHER GROUP MAY AFFECT PRIMARILY PROCESSING PROPERTIES, SOME MAY AFFECT BOTH END USE AND PROCESSING PARAMETERS. THE INCLUSION IN A RECIPE 05 A MATERIAL FROM ANY ONE GROUPING IS DONE WITH A DEFINITE PURPOSE TOWARDS A DEFINABLE RESULT,

IT IS NOT THE PURPOSE HERE TO ELABORATE ON THE FUNCTION OF EACH OF THESE MATERIAL CATEGORIES - SUFFICE IT TO SAY THAT TEXTS HAVE BEEN WRITTEN ON SUB GROUPS WITHIN A CATEGORY.

AND SO, TO THE CRITICAL PROPERTIES OF THESE RAW MATERIALS, THE MAJOR FACTOR, THE OVERRIDING CONCERN WHICH AFFECTS ALL OF THE RAW MATERIAL GROUPINGS IS THAT OF MATERIAL UNIFORMITY, MATERIAL CONSISTENCY, VARIATION OR VARIABILITY OF RAW MATERIAL REFLECTS DIRECTLY ON PROCESSING AND END USE PROPERTIES.
 

ALL OF THE RAW MATERIALS CAN BE DESCRIBED IN TWO WAYS:

1. CHEMICAL

2. PHYSICAL
 

EACH OF THE TWO DESCRIPTIONS IMPACTS MIGHTILY ON MANUFACTURE OF P.V.C. PRODUCTS.
 

1. THE CHEMICAL FACTOR DESCRIBES:

  • COMPOSITION
  • PURITY
     

2. THE PHYSICAL FACTOR DESCRIBES:

  • STATE, LIQUID, SOLID, GAS
  • VISCOSITY
  • PARTICLE SIZE - DISTRIBUTION, POROSITY, BULK DENSITY
  • COLOR
  • CONTAMINATION
     

THESE TWO FACTORS DETERMINE:

  •  WHAT THE PRODUCT WILL DO
  •  HOW WELL THE PRODUCT DOES IT

THE INTERDEPENDENCY OF EACH MATERIAL GROUPING WITHIN A RECIPE MUST BE STRESSED, THE PROPERTIES BOTH PHYSICAL AND CHEMICAL OF AN INGREDIENT CAN AND DOES AFFECT THE BEHAVIOR OF SOME OR ALL OF THE OTHER INGREDIENTS IN THAT RECIPE. ANYONE WITH THE SLIGHTEST ACQUAINTANCE WITH PLATEOUT OR BLOOM CAN APPRECIATE THE VALIDITY OF THIS STATEMENT.

SO, LET US EXAMINE SOME OF THE RAW MATERIAL CATEGORIES IN A LITTLE MORE DETAIL.
 

1. P.V.C. RESINS:
 

MAJOR PROPERTIES

EFFECTS

EFFECTS

 

PROCESS

END USE

MOLECULAR WT.

 

(SPECIFICVISCOSITY) (R VALUE)

x

x

     

PARTICLE SIZE & DISTRIBUTION

x

-

HEAT STABILITY

x

-

FISH EYES, GELS

-

x

CONTAMINATION

x

x

HEAT LOSS

x

x

BRABENDER (DRY TIME)

(FUSION TORQUE)

x -


MOLECULAR WEIGHT IS THE MOST IMPORTANT PROPERTY OF A P.V.C. RESIN AS IT DIRECTLY AFFECTS PROCESSING AND END USE PROPERTIES. PARTICLE SIZE, DISTRIBUTION, POROSITY AFFECT MELT VISCOSITY, DRY BLENDING, FLUXING, DUSTING, DRY FLOW. HEAT STABILITY CONCERNS PROCESSING. FISH EYES AND CONTAMINATION STRONGLY REFLECT ON END USE APPLICATIONS AND DEPENDING ON SEVERITY, PROCESSING.
 

2. PLASTICIZERS
 

MAJOR PROPERTIES

EFFECTS

EFFECTS

 

PROCESS

END USE

COMPOSITION

-

x

COLOR

-

x

VISCOSITY

x

-

COMPATIBILITY

x

x

VOLATILITY

-

x


GIVEN THAT THE PLASTICIZER HAS BEEN CHOSEN CORRECTLY, THE CHEMICAL COMPOSITION IS DIRECTLY RELATED TO END USE AND EFFICIENCY, COLOR IMPACTS ON THE USEFULNESS OF THE END PRODUCT. VISCOSITY IS IMPORTANT FOR TRANSPORT DURING COMPOUNDING AND FOR EASE OF DRY BLENDING. COMPATIBILITY RELATES TO END USE (EXUDATION) AND VOLATILITY TO PERMANENCE.
 

3. STABILIZERS
 

MAJOR PROPERTIES

EFFECTS

EFFECTS

 

PROCESS

END USE

COMPOSITION

x

x

PHYSICAL STATES

x

-

SOLID, LIQUID, GRANULE

 

COMPATIBILITY

x

x


THE CHEMICAL COMPOSITION IMPACTS DIRECTLY ON THE PROCESS AND END USE. ALTHOUGH MANY OTHER INGREDIENTS INFLUENCE PRODUCT STABILITY, THE STABILIZERS ARE THE FIRST LINE OF DEFENSE AGAINST DEGRADATION DUE TO HEAT AND LIGHT. VARIATIONS IN CHEMICAL COMPOSITION OR INTRODUCTION OF DILUENTS AND/OR IMPURITIES ARE READILY DISCERNIBLE.

THE PHYSICAL STATE - LIQUID, GRANULE, POWDER IS RELATED TO EASE OF DISPERSION THROUGHOUT THE BLEND AND HENCE EFFECTIVENESS. COMPATIBILITY IS ESSENTIAL FOR PERMANENCE (PLATEOUT DURING PROCESSING, BLOOM IN FINISHED PRODUCT).
 

4. FILLERS, FIRE RETARDANTS
 

MAJOR PROPERTIES

EFFECTS

EFFECTS

 

PROCESS

END USE

PARTICLE SIZE & DISTRIBUTION

x

x

COLOR

-

x

COMPOSITION

x

x

OIL ABSORPTION

x

-

 

PARTICLE SIZE IMPACTS ON DISPERSION AND OPACITY AS WELL AS SUCH END USE PROPERTIES AS COLD CRACK AND HARDNESS. OPACITY AND COLOR OF THESE ADDITIVES ARE VERY CRITICAL IN PIGMENTATION OF THE P.V.C, PRODUCTS. IMPURITIES INTRODUCED BY THIS CLASS OF RAW MATERIAL CAN BE PARTICULARLY DETRIMENTAL TO HEAT STABILITY.

 

5. LUBRICANTS

 

MAJOR PROPERTIES

EFFECTS

EFFECTS

 

PROCESS

END USE

COMPOSITION

x

-

PHYSICAL STATE

x

-

LIQUID, GRANULE,, POWDER

 

COMPATIBILITY

x

x

 

LUBRICANTS ARE CLOSELY RELATED TO STABILIZERS THEIR FUNCTION AND EFFECT, COMPOSITION AND COMPATIBILITY DETERMINE FUNCTIONALITY AND PERMANENCE (ANTI-PLATEOUT, ANTI-BLOOM). PHYSICAL STATE DETERMINES THE EASE OF DISPERSION.
 

CONCLUSION

CRITICAL PROPERTIES THEN, ARE GENERALLY DEFINED BY PURITY OF CHEMICAL COMPOSITION AND PHYSICAL FORM, SPECIFICATIONS ARE DESIGNED AROUND THESE PARAMETERS. UNIFORMITY, CONSISTENCY OF RAW MATERIAL ARE PARAMOUNT FOR OPTIMUM PROCESSING AND SUITABILITY OF END PRODUCT APPLICATION.

 

PAUL LUSSIER Canadian General-Tower, Ltd.

 

COMPARISON OF METHODS OF PVC SHEET AND FILM MANUFACTURE

     
             
   

Extruder

Blown

Flex Lip

Plastisol

 
 

Calendar

Calendar

Film

Extruder

Cast

Melt Roll

Lines installed, USA

155

2

90

40

60

5

Relative Resin Cost

Lowest

Low

Higher

Higher

Highest

Low

Machine Cost, $ Million

1-3

1-2.5

0.3-0.6

0.3-0.6

0.3-0.7

0.3-1.3

Rate & range, lb/hr

800-8000

500-1500

600

750

750

100-1000

       

(4½ in.)

(4½ in.)

with fluxer

Product gauge range, in.

.002/.050

.002/.050

.001/.003

.005/.125

.001/.012

.0015/.020

Sheet accuracy, %

3(1-5)

3(1-5)

10

10

7

5(2-10)

Time to heat, hr

6

5

3

3

½

3

Time for “on stream”

2-5 min

10 min

2 hr

5 hr

10 min

2-5 min

Gauge adjust time

Sec

Sec

5-30 min

5-30 min

Sec

1 min

Auto gauging capability

Yes

Yes

No

No

No

No

Color or product change time

5-30 min

10-40 min

30-60 min

30-60 min

15 min

30-60 min

Wind-up speed ypm,

           

average(max)

80(150)

60(80)

15(20)

15(30)

20(40)

20(30)

Limitations

High capital

Lower rate

Poor accuracy, long

Fumes,

Reduced rate

 

cost, heat time

versatility

on stream time, low

inefficiency,

and range,soft,

   

problem

rate, degradation,

 

high energy

materials only,

     

reduced versatility

cost, resin

slow manual

         

cost, release

gauge change

         

paper cost

 

Applications &

Versatility

Accuracy

Low investment

 

Grain reten-

Good on wall

Advantages

high rate

gauge adjust

multi-plant capability

tion(pattern

covering, thin

 

accuracy

reduced cost

utilization, thin gauge

cast in),

material, coated

 

ease & adjust

 

(.003in. and under)

soft hand

fabric, accuracy

 

ease at

 

and heavy gauge

 

and drape

reduced

 

re-process

 

(.050-.125in.)

   

investment

 

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