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Comtruder® - Large Plastic Pipe Production Line with CaCo3

Our last development in the field of large plastic pipes is the production of pipes filled with 25% Calcium Carbonate. The new pipe system fulfills all requirements for pipes according to the European standard EN13476. We produced several pipes on one of our latest extrusion lines with an integrated Comtruder®. During the extrusion process, PE100 and calcium carbonate powder are mixed and extruded in one step. The pipes were produced with 75% Sabic HDPE P6006 (PE100) and 25% calcium carbonate powder CaCO3 (in further tests we produced pipes with 30% calcium carbonate). The same pipes were also produced with virgin HDPE SABIC P6006 (PE100). Pipes were produced as solid wall and also as structured wall pipes.

 

 

1

 

The following pipes were manufactured:

  1. Pipe DN1000 x 6000 structured wall pipe: PR54-4.5 ends: smooth-smooth
    Material: 75% HDPE (PE100) Sabic 5005 + 25% calcium carbonate
    Output: 500 kg/hr
    Co-Ex: Yellow 31 kg/hr (for the inner surface)
    Program: 1000x6000-JB-54-4-5c-530-25CC


    Production of a structured wall pipe with CaCo3
  2. Pipe DN1000 x 2000 VW12/24 smooth-smooth ends
    Material: 75% HDPE (PE100) Sabic 6006 + 25% calcium carbonate
    Output: 450 kg/hr
    Co-Ex: Yellow 28 kg/hr (for the inner surface)
    Program: 1000x2000-JB-s12-s24c-480-25CC
  3. Pipe DN600 x 6000 VW20 smooth-smooth
    Material: 75% HDPE (PE100) Sabic 6006 + 25% calcium carbonate
    Output: 400 kg/hr
    Co-Ex: Yellow 22 kg/hr (for the inner surface)
    Program: 1000x2000-JB-s20c-420-25CC


    Production of a solid wall pipe with CaCo3
  4. Pipe DN600 x 6000 VW20 smooth-smooth
    Material: 70% HDPE (PE100) Sabic 6006 + 30% calcium carbonate
    Output: 400 kg/hr
    Co-Ex: Yellow 22 kg/hr (for the inner surface)
    Program: 1000x2000-JB-s20c-420-30CC

 

All pipes were produced with our standard machine “KDR750+”, standard dies were used and the output was according to the programmed settings. A large effect by using calcium carbonate was the significant reduction of the cooling time by approx. 10%. After the production, the pipes were stored for 24 hours before starting the pipe tests.

 

The following tests were carried out on pipe samples:

 

All tests have been carried out at the customer’s plant and also at the headquarters of Zwick in Germany.

  1. Melt Flow Rate - ISO 1133-1, at ZWICK head office in Germany
  2. Density - DIN EN ISO 1183-1, at ZWICK head office in Germany
  3. Incineration test- DIN EN ISO 3451-1 (Ash-test), at ZWICK head office in Germany
  4. Oxidation Induction Time - ISO 11357-6 or EN728, at customer´s plant and at Krah lab
  5. Ring stiffness - ISO9969 and Ring flexibility – EN1446, at customer’s plant
  6. 3-point bending test - DIN EN ISO 178, at ZWICK head office in Germany
  7. Tensile tests according - DIN527, at ZWICK-head office in Germany
  8. Burst test- at customer´s plant

 

 


1. Melt Flow Rate

Standard: DIN EN ISO 1133-1
Testing machine: ITP
Sample weight: 2.7 grams
Test parameters: temperature 190 ° C test weight 5kg
Sample interval: 5 x 120sec.

Reference sample HDPE PE100 Sample of profile pipe DN1000-PR-54-4.5
sample HDPE PE100 Sabic 6006
1 0,22
2 0,23
3 0,21
average 0,22 g/10min
sample HDPE PE100 75% + 25% CaCO3
1 0,28
2 0,27
3 0,29
average 0,28 g/10min

 

Sample of solid wall pipe DN 600 - 20
Sample of solid wall pipe DN 600 - 20
sample HDPE PE100 75% + 25% CaCO3
1 0,24
2 0,25
3 0,23
average 0,24 g/10min
sample HDPE PE100 70% + 30% CaCO3
1 0,24
2 0,24
3 0,24
average 0,24 g/10min

 

 

 

Sample of base layer from the machine
 
sample HDPE PE100 70% + 30% CaCO3
1 0,23
2 0,24
3 0,22
average 0,23 g/10min
 

 

 

2. Density

 

Standard: DIN EN ISO 1183-1
Ing scale: Kern
Sample weight: 2,5 gramm
Test fluid: Alcohol with water temperature 23 ° C.
Test methods: Method C



Reference sample

 

sample HDPE PE100 Sabic 6006
1 0,953
2 0,950
3 0,951
average 0,951 g/cm³

 

 

 

Pipe sample DN600-20

 

sample HDPE PE100 75% + 25% CaCO3
pipe sample
HDPE PE100 75% + 25% CaCO3
according to MFR-test
1 1,133 1,132
2 1,134 1,133
3 1,132 1,134
average 1,133 g/cm³ 1,133 g/cm³

 

 

Pipe sample DN600-20

 

sample HDPE PE100 70% + 30% CaCO3
pipe sample
HDPE PE100 70% + 30% CaCO3
according to MFR-test
1 1,178 1,166
2 1,180 1,168
3 1,179 1,167
average 1,179 g/cm³ 1,167 g/cm³

 

 

Pipe sample DN1000 PR54-4.5

 

sample HDPE PE100 75% + 25% CaCO3
pipe sample
HDPE PE100 75% + 25% CaCO3
according to MFR-test
1 1,159 1,137
2 1,160 1,134
3 1,158 1,134
average 1,159 g/cm³ 1,135 g/cm³

 

 

Sample of base layer from the machine

 

sample HDPE PE100 70% + 30% CaCO3
pipe sample
HDPE PE100 70% + 30% CaCO3
according to MFR-test
1 1,182 1,180
2 1,184 1,182
3 1,181 1,178
average 1,182 g/cm³ 1,180 g/cm³

 

 

3. Ash-Test

Standard: DIN EN ISO 3451-1
Test parameters:
Method A direct implementation after burn up
Material: 75%/25% calcium carbonate PE100
Profiled pipes samples DN1000 PR54-4.5
Temperature: 600°C / 650°C
Annealing time: 30min. / 2h
Number of inspections: 3

 

 

 

Pipe sample DN1000 PR54-4.5

 

  600°C / 30min. 650°C / 2h
sample HDPE PE100 75% + 25% CaCO3 HDPE PE100 75% + 25% CaCO3
1 24,83 % 22,60 %
2 24,93 % 22,57 %
3 24,85 % 22,55 %
average 24,87 % 22,57 %

 

 

Pipe sample DN600 VW20

 

  600°C / 30min. 650°C / 2h
sample HDPE PE100 75% + 25% CaCO3 HDPE PE100 75% + 25% CaCO3
1 23,52 % 23,08 %
2 23,59 % 23,04 %
3 23,54 % 23,07 %
average 23,55 % 23,06 %

 

 

Pipe Sample DN600 VW20

 

  600°C / 30min. 650°C / 2h
sample HDPE PE100 70% + 30% CaCO3 HDPE PE100 70% + 30% CaCO3
1 27,24 % 26,45 %
2 27,28 % 26,50 %
3 27,26 % 26,46 %
average 27,26 % 26,47 %

 

 

Sample of base layer from the machine

 

  600°C / 30min. 650°C / 2h
sample HDPE PE100 70% + 30% CaCO3 HDPE PE100 70% + 30% CaCO3
1 29,27 % 28,48 %
2 29,20 % 28,55 %
3 29,26 % 28,53 %
average 29,24 % 28,52 %

 

 

4. Oxidation Induction Time

 

Standard: ISO 11357-6 or EN728
Testing machine: DSC 550
Material: 75% HDPE PE100 + 25% CaCO3 / 70% of HDPE PE100 + 30% CaCO3
Temperature: 200°C
Gases used: Nitrogen / Air
 

 Pipe sample DN1000 - PR54-4.5

 

sample HDPE PE100 75% + 25% CaCO3
1 77,79 min.

 

Test stopped !

 

Pipe sample DN600-VW20

 

 

sample HDPE PE100 75% + 25% CaCO3
1 57,25 min.

 

 

Test stopped !

 

Pipe sample DN600-VW20

 

 

sample HDPE PE100 70% + 30% CaCO3
1 69,80 min.

 

 

Test stopped !

 

Sample of base layer from the machine

 

 

sample HDPE PE100 70% + 30% CaCO3
1 44,85 min.

 

Test stopped !

 

 The minimum value for PE material is 20 minutes and 8 minutes for PP – therefore all tests were stopped.

 

5. Nominal Stiffness / Ring Flexibility

 

 Standard: ISO9969  




  EN1446
Testing machine: Zwick ring stiffness
Specimens from: Pipe DN1000 PR54-4.5
Length of the specimen:

≥ 400mm

Material: 75% HDPE PE100 + 25% CaCO3
Ambient temperature:






23°C

 

                 

Test result:

 

sample HDPE PE100 Sabic 6006
N/m²
HDPE PE100 75% + 25% CaCO3
N/m2
1 4315,53 4960,95
2 4181,37 5149,62
3 4009,24 5364,47
average 4168,71 5158,34

 

 

 

Comment:
By using a pipe with a 25% proportion of CaCO3, the profile height of 4mm was lower than initially planned , therefore it can be assumed that the stiffness will be higher by reaching the normal value.

Ring Flexibility (30%) – according to EN1446

During the Stiffness Test a „Flexibility Test 30%“was carried out. Here, the pipes were free of cracks and the loads have never decreased.

 

6. Bending E-Modul

 

Standard:
Testing machine:
Specimens from:
Length of the specimen:
Test speed:

Sampling:
Material:

Ambient temperature:

according to DIN EN ISO178
Zwick ring stiffness
Pipe DN1000 VW12/24
80x10x4mm
2mm/min.
10mm/min.
axial / circumferential
75% HDPE PE100 + 25% CaCO3
70% HDPE PE100 + 30% CaCO3
23°C

 

 

 

 

 

Reference value

HDPE PE100 Sabic 6006

 

sample Axial direction
modulus of elasticity MPa
Circumferential direction
modulus of elasticity MPa
1 951,85 992,86
2 988,13 996,80
3 949,27 990,59
4 965,86 992,94
5 972,13 991,12
average 965,44 992,86

 

 

HDPE PE100 75% + 25% CaCO3

 

 

sample Axial direction
modulus of elasticity MPa
Circumferential direction
modulus of elasticity MPa
1 1290 1570
2 1417 1184
3 1399 1354
4 1465 1302
5 1431 1236
average 1400 1329

 

 

HDPE PE100 70% + 30% CaCO3

 

 

sample Axial direction
modulus of elasticity MPa
Circumferential direction
modulus of elasticity MPa
1 1453 1443
2 1520 1338
3 1570 1501
4 1468 -
5 - -
average 1503

1427

 

 

7. Tensile tests

 

Standard:
Testing machine:
Specimens from:
Test specimens:
Test speed:
Sampling:
Sample thickness:
Material:


Ambient temperature:
DIN527-1 and E-modulus determination
Zwick tensile testing machine
Pipe DN1000 VW12/24
Type 1-B
1mm/min. 50mm/min
scope and axial direction
5-6mm
100% HDPE PE100 (Sabic 6006)
75% HDPE PE100 + 25% CaCO3
70% HDPE PE100 + 30% CaCO3
23°C

 

 

 Material HDPE PE100 Sabic 6006

 

sample Circumferential direction
modulus of elasticity MPa
Nominal
elonagtion at break %
1 1024 635
2 1052 621
3 1050 624
4 1045 626
5 1060 635
average 1046,2 628,2

 

 

Material HDPE PE100 (75% + 25% calcium carbonate)

 

 

sample Circumferential direction
modulus of elasticity MPa
Axial direction
modulus of elasticity MPa
1 1227 1369
2 1303 1386
3 1261 1400
4 1304 1404
5 - 1415
average 1273,75 1394,8

 

 

Material HDPE PE100 (70% + 30% calcium carbonate)

 

 

sample Circumferential direction
modulus of elasticity MPa
Axial direction
modulus of elasticity MPa
1 1219 1504
2 1317 1527
3 1253 1512
4 1306 -
5 1248 -
average 1268,6 1514,3

 

 

8. Burst pressure test

Internal pressure burst test

 

Testing machine:
Tube sample:
Material:
Test parameters:
Test parameters:

SCITEQ
DN600-VW15 x 1200 mm
HDPE PE100 75% + 25% CaCO3
water temperature in the pool 80°C
pressure load up to broken pipe

 

 

For this test, pipes with a diameter of DN600-VW20 and with a material composition of HDPE PE100 75% + 25% CaCO3 were used. Due to thickness shrinkages, a thickness of 15mm was produced. This thickness corresponds to a production of 100% of PE100 with pressure category PN4.

The sample was specially tailored to a length of 1200mm, so that there is a length of 1000 mm provided between the end caps.

The end caps are made out of steel and were provided for an outside diameter of 630mm. An O-ring with a diameter of 12mm was integrated in the inside of the end caps.

Then the test pipe was completely filled with water and was put into the pre-heated pool with a water temperature of 80 ° C. After a relaxing time of about 1 hour, the pressure load was started.

We started with a pressure of 5 bar and kept the load. After that, we started to increase the pressure by 1 bar steps. At an internal pressure of 9 bar, we were not able to ensure a constant test pressure. Therefore the pressure was reduced to 7 bar. The pipe was taken out of the pool for inspection. No damage was determined. The test sample was placed in a separate pipe for security reasons.

At a test pressure of 9 bar, a leak was discovered at the two end caps. This leakage was caused by the significant change in the pipe diameter and therefore the leakage could not be prevented with the help of the end caps. Both end caps were not leaktight.

Preparation of the end caps for testing

Rub the rubber gasket with liquid soap

Preparing for a solid wall pipe pressure test and faces beveling

Pipe fixed at the end caps and fixed with tension struts

 

 

Filling of the sample pipe with water

 

Transport of the sample pipe into a pool (80°C)

 

and add the pressure hose

 

Terminations of the test run with 7 bar internal pressure. Then the pipe was taken out of the pool.


Clearly visible bulging of the pipe

 

Inspection of the pipe

The test pipe was placed in a separate larger pipe for safety reasons.

Put the pipe under pressure of up to 9 bar.

 

 


Leak was discovered at the two end caps. Pipe is not damaged.
(See chart below - bottom side of the end cap)

 

(see chart below - top end cap)

 

Terminations of the test run

 

 

 

Result

 

All given values (EN13476) were maintained without any problems and the pipe meets the standard as well as the EN13476-2 annex “E”.

Further tests will be carried out shortly.

Jochen Blickheuser

Quality and Application Engineer