Plastic Specification Sheets

Entrepreneurs Conference

October 27, 2010

Dennis L. HayfordExecutive Director

Discussion of ASTM testing and other test methods for Property Sheets.

I’m not here to teach chemistry.

But I am here to talk a little about plastics, and Property Sheets!

I want to shed a little light on Property Sheets!

Before we begin:This is a discussion about properties and, While references are made to ASTM,ASTM does not sanction what is said here.The attendee is urged to read ASTM test methods buy them and, Subscribe to their proper use.ASTM American

Society forTesting andMaterials

http://www.astm.org/index.shtml

Why would anyone want to do any of this?

Property Sheets:Property sheets are an attempt to physically characterize a product being sold.Often the Property Sheets do not contain all of the information.

Both buyer and seller are responsible.

The better the description,

The better the price!

The better the understanding between parties and,

Property Sheets can enhance trust.

The most important thing is to:Determine the polymer properties and,

What methods to use.

Choose a good test lab:

ISO 9001:2008 standard.

Reliable,

A2LA or ISO 17025 is too high of a standard,

(Too expensive!)

3 Grades of recyclable face fiber carpet:

Note:Technical terms relating to plastics are defined in ASTM D883 & ASTM D1600

3 Grades of recyclable face fiber carpet:

Grade III-sheared or pulverized,

3 Grades of recyclable face carpet:

Grade II-Densified and,


Grade I-Pelletized or reprocessed.





The devil is in the details!

Lets talk about the devil.

Name the device.

Include the model number.

Hand held “near” FTIR:

Hand held near infrared spectrometers are available.

Such as this one by Phazir™.

Handheld “near” FTIR:

Light weight and portable.

Handheld “near” FTIR:

And this one by Anavo™

A picture can say 1,000 words!

ASTM D5630 Ash ContentThe purpose of this test is to determine the inorganic content of plastics.There are two methods described:

Procedure A , Muffle –Furnace Technique-For 5-50 gram samples. Samples are flamed over a burner prior to being ashed in a muffle furnace.

Procedure B, Rapid –Ash Muffle-Furnace Technique- For 5-50 gram samples. Samples are ignited and ashed in a muffle furnace.

ASTM D5630 Ash Content

Sample in a crucible is carefully weighted before being placed in a muffle oven,Muffle oven is heated to at 850 OC (for nylon)

Procedure B:

For 10 minutes. (See tables for other mtls.)

Note: Some companies use their own procedure.

ASTM D5630 Ash ContentCarefully weight crucible after heating and cooled.

AGAIN Caution! Some companies have their own methods! Ask about them!

Mostly there is a variance in time and temperature.

The difference in weight expressed as a percent is the percent ash content.

ASTM D5630 Ash Content –Standard TestFor nylon 6/6

ASTM Method

Temp 900 CTime 20 min

Sample IDEmpty

Crucible weight

With sample weight

With ash crucible weight

Ash mass

Grams Grams Grams %1 25.97575 28.51641 26.57111 23.4%2 17.52647 20.67049 18.42834 28.7%

26.1%

ASTM D5630 Ash Content-Modified versionFor nylon 6/6

Temp 600 CTime 45 min

Sample IDEmpty

Crucible weight

With sample weight

With ash crucible weight

Ash mass

Grams Grams Grams %1 21.48102 24.45749 22.96576 49.9%2 18.22432 21.11857 19.56138 46.2%

48.0%

Modified Method

ASTM D5630 Ash Content-Discussion

If the filler is calcium carbonate (CaCO3), As in this case,

It will start to decompose to CaO above 600 oC.The ash content can significantly vary.

ASTM D789 Moisture Content-simple loss in weight

ASTM D789 Moisture Content-simple loss in weight

Heaters

Resin pan

Read out

ASTM D789 Moisture Content-simple loss in weight.

The results, while not the true moisture content,

Is expressed as a percent. (%)

But volatiles, including moisture,

Contaminates:

Including a picture is worth 1,000 words.

Describe if possible,

Two additional Properties:

Bulk (Apparent) Density-ASTM D1895

Density (of the material)-ASTM D792

ASTM D 1895 Bulk (Apparent) Density

(The real question is how much space does this stuff take up? Or pounds per cubic foot!)

The weight per unit volume of a material, including voids inherent in the materials as tested.

Measure a volume of material as packaged.Weigh it.Divide the volume into the weight.

Very simply expressed, (but remember ASTM has rules as to how this is done).

To get pounds/foot3 (or inch3).

ASTM D1895 Bulk (Apparent) Density

Height

Length

Width

Weight

Be sure to note by crossing off the Per ASTM method!

ASTM D792 Density (Specific Gravity) by Displacement.There are two methods used:

Test method A,testing solid plastics in water.Test method B,testing solid plastics in liquids other than water.

Test method B

Because we know that plastics ~ S.G. ~ water S.G.

1. Be sure that the sample is free of voids.

ASTM D792 Density (Specific Gravity) by Displacement. (B)

2. Carefully compression mold the sample to be tested.

3. Cut the sample to a convenient size and also check for voids.

(We use a Carver hydraulic press to make sure samples are void free!)


4. Weigh the dry sample on a good scale.


(Use a pure alcohol, such as Isopropyl alcohol without water in it!)

Thermometer

ASTM D792 Density (Specific Gravity) by Displacement (B)

5. Weigh the sample in alcohol (the other liquid)

The calculations are:

ASTM D792 Density (Specific Gravity) by Displacement (B)

Sample Dry weight = 1.14323 gms. (F)Buoyancy weight = 0.20618 gms. (G)

Density of test liquid = 0.78413551 gms/cc. (H)

Or 1.14323 gms/(0.20618 gms * 0.78413551 gms/cc) Sample Density then is B = F/(G * H) gms/cc

Density = 0.9575 gms/ccMedia is pure alcohol.Monitor the Temperature.

ASTM D792 Density (Specific Gravity) by Displacement (B) example.

PCE Project no. 3250Material HPDELot No.

Sample Sample weight in air (g)

Sample weight in medium (g)

Sample buoyancy (g)

Test liquid temperature

(C)

Density of Test liquid

(g/cm^3)

Specific gravity (g/cm^3)

0717-0731-2010 1.14323 0.20618 0.937050 21.7 0.78413551 0.9567

0717-0731-2010 1.04412 0.18950 0.854620 21.7 0.78413551 0.9580

0717-0731-2010 1.08211 0.19628 0.885830 21.7 0.78413551 0.9579

0717-0731-2010 1.17397 0.21255 0.961420 21.7 0.78413551 0.9575

0717-0731-2010 1.24745 0.22569 1.021760 21.7 0.78413551 0.9573

avg: 0.9575std dev: 0.0005

Name the grade (6 or 6/6)

ASTM D638 Tensile Strength

The first need is a test specimen!

Sometimes called a “dog bone”.


Clamp it in the jaws.


Add the extension meters.Pull


Yield point. (exaggerated)


Specimen at break.


Yield Break

Tensile Modulus

Tensile Strength

ASTM D639 Elongation to break

The distance between the “no stress” point and the break point!

Expressed as a percent.

ASTM D790 Flexural Modulus

(Sometimes called the 3 point bend test.)


Strain (%)

Stress(psi)


The results then is psi/% and,

Is expressed in psi.

ASTM D3418 Differential Scanning Calorimeter – or DSC

We happen to have a Perkin Elmer

But there are others:

TA Instruments

Mettler Toledo

ASTM D3418 Differential Scanning Calorimeter - or DSC

Heat flow (milli-watts)

Temperature oC

Nylon 6 (PA6)

Melt Pt.

Solid Pt.

As we close:This has been a discussion about properties and, While references are made to ASTM,ASTM does not sanction what is said here.The attendee is urged to read ASTM test methods, buy them and, Subscribe to their proper use.

ASTM AmericanSociety for Testing and, Materials

http://www.astm.org/index.shtml

.

Questions?

Plastic Specification Sheets

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