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Technical Workshop on Product Quality - Candle Waxes 1

World Candle Congress Orlando, FL 20,21 Apr-2004

Candle Wax Product Quality

A Technical Workshop for the World Candle Congress

presented by ALAFAVE & the National Candle Association

Orlando, FL 20,21-April-2004

Presenters:Carl Hudson, ExxonMobil

Ed Calcote, Shell



Workshop Topics

Produce Quality Wax on Spec

Avoid Contamination During Shipping

Maintain Product Quality Before/During Use



Wax - Component in Candle “System”

WAX: PROVIDES STRUCTURE; INFLUENCES APPEARANCE

QUALITY OF A CANDLE SYSTEM -

RESULT OF OVERALL DESIGN & FORMULATION

WICK - FUEL: NEED BALANCE FOR OPTIMUM BURNING

GOAL =WAX + ADDITIVES ---> CO2 + H2O

FRAGRANCE:MINIMUM ODOR

FROM WAX;WAX HELPS “HOLD”

& “THROW”FRAGRANCE

COLOR: MINIMUM IMPACT

FROM WAX COLOR

CONTAINER OR HOLDER IF REQUIRED



Wax Selection Tied to Candle Type

PILLAR & TAPER CANDLES+ FULLY REFINED WAX - HIGHER MELT POINT

– HARDER (HIGHER n-PARAFFIN %, NARROWER SPREAD)– LOWER OIL CONTENT

CONTAINER & JAR CANDLES+ FULLY REFINED, SCALE OR SEMI-REFINED WAX - LOWER MELT POINT

– SOFTER (LOWER n-PARAFFIN %, WIDER SPREAD)– CAN HAVE HIGHER OIL CONTENT

VOTIVE CANDLES+ FULLY REFINED, SCALE OR SEMI-REFINED WAX - LOWER MELT POINT

– SOFTER (LOWER n-PARAFFIN %, WIDER SPREAD)– OFTEN WITH HIGHER OIL CONTENT



Characterization of Candle Waxes

MELT/CONGEAL POINT - TEMP. OF LIQUID/SOLID PHASE CHANGE OIL CONTENT - LIQUIDS SOLVENT EXTRACTED FROM CHILLED WAX

COLOR - COLOR OF LIQUID WAX (Saybolt or ASTM Scale)

ODOR - ODOR COMPARISON OF SOLID WAX

NEEDLE PENETRATION - MEASURES HARDNESS OF SOLID WAX

VISCOSITY - RESISTANCE TO FLOW OF LIQUID WAX

FLASH POINT - MINIMUM TEMPERATURE OF LIQUID WAX THAT PRODUCES FLAMMABLE VAPOR PHASE

FDA GRADE (PASS/FAIL) - UV ABSORBANCE TEST TO IDENTIFY PRESENCE OF POLYNUCLEAR AROMATICS

GAS CHROMATOGRAPHY (GC) - CARBON NUMBER DISTRIBUTION

DIFFERENTIAL SCANNING CALORIMETRY (DSC) - HEAT OF TRANSITION DURING LIQUID/SOLID PHASE CHANGES



ASTM D87 Melt or D938 Congeal Methods

Test Method Reproducibility Gives Range of Answers Typical Reproducibility for ASTM D87 Melt Point, Deg F

126.0

126.5

127.0

127.5

128.0

128.5

129.0

129.5

130.0

130.5

131.0

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Deg

F Reproducibility Range

ASTM Wax Crosscheck Program Sample - WX 0202

Acceptable ASTM D87 Test Method ValuesRanged from 127.4 to 128.8 degF

Spec. Range for MP Typically

3-5 degF

CofA Value Typically

Represents+ / - 0.5 degF



ASTM D87 Results for Mid-Melt Paraffin

18 Month Results Consistent Within Spec. Range

Spec. Range57.8-59.4oC


Represents+ / - 0.5 degF

57.80

58.00

58.20

58.40

58.60

58.80

59.00

59.20

59.40

0 20 40 60 80 100 120 140

ASTM D87 Reproducibility Range



ASTM D721 Oil-in-Wax (OIW) Method

Test Method Reproducibility Gives Range of Answers

Spec. Range for FRW OIW Typically 0.0-0.5 %

Typical Reproducibility for ASTM D721 OIW, wt%

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.6

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Deg

F

Reproducibility Range

ASTM Wax Crosscheck Program Sample - WX 0202

Valid ASTM D721 Test Method ValuesRanged from 0.05 to 0.45%


Represents+ / - 0.15 %



ASTM D156 / 6045 Saybolt Color Method

Saybolt Color of +30 = Water White (no color)

Saybolt Color of +26 = Faint Straw

Saybolt Color of +24 = Light Straw Yellow

Saybolt Color of +20 = Straw Yellow

Demonstration: Representative Color Samples

Typical Spec. Saybolt Color Ranges (Reproducibility + / - 1)Fully Refined Wax +28 to +30Semi-Refined Wax +20 to +30Scale Wax +10 to +25Slack Wax < +20 down to <-16 (ASTM scale)



ASTM D1833 Cold Odor Method

Odor Testing Can Be Very Subjective!

DewaxingSolvent

Primary Odor Concerns:

Contami-nants Oxidation

Demonstration: Odor Panel with Prepared Wax SamplesTypical Odor Specs. [Scale 0-4; Reproducibility + / - 1]

Fully Refined Wax 0 to 1Semi-Refined Wax 0 to 1Scale Wax > 1Slack Wax > 2



Are All 130oF MP Waxes The Same?

NO ! And, Here Are Some Reasons Why:

Oil ContentMore oil

lowers MPsoftens wax

0

2

4

6

8

10

12

14

18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

Carbon Number

%

Straight Cut:Nominal Carbon 27PEN @ 40C 95 dmm95% Cutwidth 13-14

Blended Wax:Nominal Carbon 31PEN @ 40C 120 dmm95% Cutwidth 19

% n-ParaffinHigher % n-Par

raises MPhardens wax

Straight Cut or Blend



Wax Loading & Shipping

Molten Wax by Truck Short Hauls (<600 mi); 45,000 lbRequires Immediate UnloadingConcerns: Previous Load Contaminants; Particulates

Molten Wax by RailcarLonger Hauls; 150,000 lbCan Be Heated for Offloading as RequiredConcerns: Previous Load Contaminants; Particulates;Oxidative Degradation from Overheating

Solid Wax in Slabs, PelletsConcerns: Dust/Particulates; Discoloration (long-term);Previous Product Contamination (in packaging equip.)



Wax Storage & Handling

Recommended Bulk Storage Tank Temperature is 20-30oF Above Wax Melt or Congeal Point

+ Helps Insure Homogeneous Product + Reduces Risk of Degradation Due to Oxidation

Smaller “Day or Run” Tank Recommended if Higher Temperature Needed for Manufacturing

Storage Tank Recommendations + Outlet 12” Above Tank Bottom + “Y” Duplex Strainers or Filters (60 mesh)+ Clean Filters Regularly (monthly)+ Drain Water from Tank Bottom Regularly



Summary Points

Produce Quality Wax on SpecUnderstand Wax Specifications / PropertiesPurchase Quality Wax from Dependable Supplier

Avoid Contamination During ShippingInspect / Analyze Wax Upon ArrivalCheck CofA vs. Wax Specifications

Maintain Product Quality Before / During UseUnload & Store Wax ProperlyAvoid Overheating & Particulate Contamination



Wax PQ Workshop - Legal Disclaimer

Please Note: "With respect to the information provided herein, neither Exxon Mobil

Corporation, Shell Oil Products US, Shell Global Solutions (US) Inc., nor their affiliates nor any of their employees makes any warranty, express or implied, including warranties of fitness for a particular purpose, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any apparatus, product or processdisclosed or represents that its use would not infringe on privately owned rights. In no event shall Exxon Mobil Corporation or Shell Oil Products US or Shell Global Solutions (US) Inc. be liable for any direct, indirect, incidental, punitive, or consequential damages of any kind whatsoever with respect to the materials and the products referenced in this presentation."



Wax PQ Workshop - Back-Up Info

Composition Influences Wax PropertiesCarbon Distribution by Wax GCOil vs. Wax Defined by Solubility TestDewaxing/Deoiling to Obtain Wax (from Lube Oils)Wax Oxidation IssuesOthers?



Composition Influences Wax Properties

Increasing Value Melting Point Hardness Shrinkage

Average CarbonNumber

n-Paraffin Content, %

Carbon NumberSpread

Oil Content, %

20 - 50 FRP35 - 80 Micro

Typical Range

10 - 25 FRP25 - 40 Micro

< 0.5 FRP1 - 5 Scale

1 - 10 Micro

50-90% FRP< 10% Micro



Carbon Distribution by Wax GC

1. CARBON NUMBER - WAX GRADE; MELT POINT2. NORMAL TO ISO RATIO - IMPACTS HARDNESS; MP3. 95% CUTWIDTH - IMPACTS HARDNESS; MP

0

2

4

6

8

10

12

14

18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45

Carbon Number

%Total Paraffins

Nominal Carbon 25

95% Cutwidth 13

n-Paraffins - 80%

iso-Paraffins - 20%

1

2

3



Oil vs. Wax - Defined by Solubility Test

ASTM D-7211.0 g Wax15 mL Methyl ethyl ketone< -30oC with stirring

COLD!

WAX+

MEK+

OIL

WARM!

WAX

MEK+

OIL

Filter the wax

MEK EVAPORATES

OIL

Remove solventWeigh residual oil

NOTE: Temperature Determines Molecule Solubility, i.e., Oil Content is Defined by the Conditions of the Method.



Dewaxing/Deoiling to Obtain Wax

CHILLING/CHILLING/WAX CRYSTALLIZATIONWAX CRYSTALLIZATION

DEWAXING SOLVENTDEWAXING SOLVENT

WAX &WAX &OILOIL

DEWAXEDDEWAXEDOILOIL

SOLVENTSOLVENTRECOVERYRECOVERY

ROTARYROTARYFILTRATIONFILTRATION

STAGESTAGE

WAX

1st Stage SLACK WAX 5-30% OIL

2nd Stage SCALE / SEMI-REFINED WAX 1-5% OIL

3rd Stage REFINED WAX <1% OIL



Wax Oxidation Issues

Wax Oxidizes Over Time at Elevated Temperature + Can Produce Yellow-Brown Color + Objectionable Odors Can Result+ Forms Heavy Molecules That Can Create Sludge

If Tank of Wax Becomes Oxidized, Complete Drain & Clean Sequence is Highly Recommended

To Minimize Detrimental Effects of Oxidation + Keep Wax Temperature as Low as Possible + Recommend 20-30oF Above Melt/Congeal Point+ Use Anti-Oxidants as Needed (e.g., BHT)

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