Chapter 29
High Density Polyethylene = HDPE Category: Polyolefin General Description: High density polyethylene (HDPE) polymers are highly crystalline, tough materials. High molecular-weight, high density polyethylenes (HMW-HDPE) are a special class of linear resins with molecular weights in the 200,000 to 500,000 range. To obtain processability along with end-use properties, control of the molecular weight distribution is critical. Some materials are produced with “bimodal” molecular weight distribution to obtain the necessary balance.[loo4] Equistar Chemicals:[l15*1
Alathon L 5876, L 5885, A4 6210, A4 6001, and A4 6020. A high density, medium molecular-weight homopolymer. Alathon A4 6030, A4 606 and A4 5865. A medium molecular-weight, high density homopolymer with extremely low gel content. This resin provides high stiffness and narrow molecular weight distribution for use in cast film applications. Alathon L 4903. A high molecularweight, high density copolymer with broad bimodal molecular weight distribution. This resin exhibits excellent machine-direction tear in an HMWHD resin as well as low gel levels. Alathon L 5005. A high molecularweight, high density copolymer that provides broad bimodal molecular weight distribution, high stifhess, and good heat-seal response and strength.
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Alathon L 4907. A high molecularweight, high density copolymer with broad bimodal molecular weight distribution. This resin exhibits high density and stiffness, and is designed for grooved feed and smooth bore equipment.
ExxonMobil:[ll4l]
Paxon 4700. A medium molecularweight, high density polyethylene homopolymer film resin. Pax-Plus 3201. A rubber-modified film resin that exhibits excellent impact strength and stress-crack resistance. It is used primarily in film where its good tear resistance and laminating properties are required. Pax-Plus 3303. A rubber-modified film resin that exhibits good toughness and easy processing. Its major uses are for film requiring good odor and moisture barrier properties and superior thermal properties. Pax-Plus 3205. A rubber-modified film resin. Its major use is in films that require good WVTR and excellent tear resistance. It offers a good combination of toughness, flexibility, and processing into blown film. Film Processing Methods: High density polyethylene can be formed by most processing methods; most films are blown films.
Ch. 29: High Density Polyethylene - HDPE
114 Film Applications: Food packaging: dairy products and bottled water; cosmetics; medical products; household chemicals; automotive gas tanks; 55 gallon drums; sheet; pipe; recreational items; geosynthetic materials. Regulatory Approval: The Equistar Chemicals Alathon grades listed herein meet the requirements of the Food and Drug Administration regulation 21 CFR 177.1520.[1158] Exxon Mobil Paxon 4700 resins meets all the requirements of the FDA for olefin polymers to be used as
articles or components of articles for contact with foodas set forthin21 CFR 177.1520(c) 2.1,2.2, and 2.3.[11411 ExxonMobil Pax-Plus 3201,3205, and 3303 meet all the requirements of the FDA for olefin polymers to be used as articles or components of articles for contact with food as set forth in 2 1 CFR 177.1520 (c) 3.1 and3.2a and21 CFR 177.1420.[1141]
Film Properties by Material Supplier Trade Name: See Tables 29-01 through 29-04.
Table 29-01. Physical Properties of Equistar Chemicals Alathon HDPE for Carton Liners
I
Material Family
I L saas
L 5876
I
Reference Number
I
HIGH DENSITY POLYETHYLENE (HDPE)
I
M 6210
M 6001
M 6020
I
1158
Sample Thickness (mm)
0.051
PHYSICAL PROPERTIES
I
36
18
21
16
22
Tear Strength (Elmendorf) TD (9)
600
900
500
450
500
Secant Modulus, MD1TD (MPa)
I I
TEST METHOD
Tear Strength (Elmendorf) MD (9)
Elongation at Break, MD/TD (%)
Tensile Strength at Break, MD1TD Tensile Strength at Yield, MD1TD (MW
I
I
I I
6001800 8271965
44138 26119
I
700/750 86211,000
82711,034
86211,000
I
8601850
27127
26126
I
82711,069
1 - 1 - 1 - 1 - 1 I I I I 26126
ASTM D1922
23121
ASTM D882
I
MD-Machine Direction; TD-Transverse Direction.
Ch. 29: High Density Polyethylene - HDPE
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115 Table 29-02. Physical Properties of Equistar Chemicals Alathon HDPE for Cast Film
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Material Family
I M 6030
M 6060
Reference Number
I
Sample Thickness (mm)
I
HIGH DENSITY POLYETHYLENE (HDPE) M 5865
1158
I
I
0.051
PHYSICAL PROPERTIES
I
TEST METHOD
Tear Strength (Elmendorf) MD/TD (9)
201500
-
-
Elongation at Break, MD/TD, MPa (%)
8601850
8501650
9001800
Secant Modulus, MD/TD (MPa)
I
6901827
Tensile Strength at Yield, MD/TD (MP4
I
22121
24126
ASTM D1922
I
79311,034
ASTMD882
I
ASTMF1249
I
24125
PERMEABILITY PROPERTIES Water Vapor Transmission Rate (g mmlm2 day)
I
I
3.14
I
I
MD-Machine Direction; TD-Transverse Direction.
Table 29-03. Physical Properties of Equistar Chemicals Alathon HMW-HDPE for Film
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Material Family
I
HIGH DENSITY POLYETHYLENE (HDPE) Equistar Chemical Alathon
Material SupplierlGrade
L 4903
L 4907
L 5005 1158
Reference Number MATERIAL CHARACTERISTICS
I
Sample Thickness (mm)
I
0.125
I
-
I
0.0125
PHYSICAL PROPERTIES
I
I TESTMETHOD
1.8
2.05
2.0
ASTM D3420
20118
14135
11150
ASTM D1922
Elongation at Break, MD/TD, (%)
3901260
3001420
3801420
Secant Modulus, MDITD (MPa)
11521979
7931965
106911048
Tensile Strength at Break, MDITD (%)
65167
59135
58147
Tensile Strength at Yield, MDITD (%)
4 1134
26123
31127
Dart Drop, Total Energy (ft-lb) Tear Strength (Elmendorf) MDITD (9)
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ASTM D882
Ch. 29: High Density Polyethylene - HDPE
116 Table 29-04. Physical Properties of ExxonMobil HDPE for Blown Film
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Material Family
I
Material SupplieriGrade
I
Reference Number
Sample Thickness (mm)
Paxon 4700
Pax-Plus 2301
I
Tear Strength (Elmendorf) MD/TD (N1mm2) Elongation at Break, MD/TD, (%) Secant Modulus, MD/TD (MPa)
Pax-Plus 3303
Pax-Plus 3205
I
1141
0.025
I
0.051
Coefficient of Friction static, MD1TD kinetic, MD1TD Dart Drop, Impact Strength, 50% (9)
I
HIGH DENSITY POLYETHYLENE (HDPE)
0,8210.70 0,7710.65
0,8210.70 0,7910.67
0.9110.96 0.8910.80
ASTM D1894
35
410
190
260
ASTM D1709
5196
1O i l 80
51212
1OR50
ASTM D1922
4201420
5901840
5501800
5001750
-
-
1030/1100
Tensile Strength at Break, MD/TD (MPa)
37130
Tensile Strength at Yield, MD/TD (MPa)
39135
PERMEABILITY PROPERTIES Gas Transmission Rate, 02 (cm3, mm1m2, day, atm)
141
Water Vapor Transmission Rate, IOO"F, 90% RH (g mm1m2 day)
0.3
I MD-Machine Direction; TD-Transverse Direction.
Ch. 29: High Density Polyethylene - HDPE
I I I I
30120 20110
45.9
I I I 0.1428
34123 24116
64.8
I I I I
30120 20110
57.6 0.168
I I I I
D882
ASTM D3985
I
ASTMF372
I
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