MULTILAYER STRUCTURE BASED ON RECYCLED POLYAMIDE

Abstract

A multilayer tubular structure (MLT) for transporting fluids for a motor vehicle, including at least three layers: at least one layer having a composition predominantly including at least one semi-crystalline aliphatic polyamide, the composition having at least 50% of recycled material from a single-layer and/or multilayer tube that has been intended for transporting fluids for a motor vehicle, the tube having a composition which predominantly includes at least one polyamide, at least one layer having a composition predominantly including at least one semi-crystalline aliphatic polyamide and optionally at least one impact modifier, and when the layer has a composition predominantly including at least one semi-crystalline aliphatic polyamide that is PA12 and/or PA612 and/or PA1010, then the composition includes the impact modifier, and at least one layer having a composition predominantly including at least one semi-crystalline aliphatic polyamide, the layer and the layer each having at least 90% of non-recycled material.

Claims

1. A multilayer tubular structure (MLT) for transporting fluids for a motor vehicle, the structure comprising at least three layers: at least one layer (1) consisting of a composition predominantly comprising at least one semi-crystalline aliphatic polyamide, said composition consisting of at least 50% of recycled material from a single layer and/or multilayer tube that initially transported fluids for a motor vehicle, said tube consisting of a composition that predominantly comprises at least one polyamide, at least one layer (2) consisting of a composition predominantly comprising at least one semi-crystalline aliphatic polyamide and optionally at least one impact modifier, and when layer (2) consists of a composition predominantly comprising at least one semi-crystalline aliphatic polyamide that is PA12 and/or PA612 and/or PA1010, then said composition comprises said impact modifier, and at least one layer (2′) consisting of a composition predominantly comprising at least one semi-crystalline aliphatic polyamide, said layer (2) and said layer (2′) each consisting of at least 90% of non-recycled material.

2. The multilayer tubular structure (MLT) according to claim 1, wherein said layer (1) is located between a layer (2) and a layer (2′).

3. The multilayer tubular structure (MLT) according to claim 1, wherein layer (2′) is the layer in contact with the fluid.

4. The multilayer tubular structure (MLT) according to claim 1, wherein layer (2′) is as defined for layer (2).

5. The multilayer tubular structure (MLT) according to claim 1, wherein at least one binder layer (3) is present, said layer (3) being located between layer (2) and layer (1) and/or between layer (1) and layer (2′).

6. The multilayer tubular structure (MLT) according to claim 1, wherein said layer (1) represents at least 10% of the total thickness of said multilayer tubular structure (MLT).

7. The multilayer tubular structure (MLT) according to claim 1, wherein said layer (1) consists of a composition comprising: at least 50% by weight of at least one semi-crystalline aliphatic polyamide denoted C having an average number of carbon atoms per nitrogen atom denoted C.sub.C comprised from 6 to 18; from 0 to 25% by weight of at least one semi-crystalline aliphatic polyamide denoted B and having an average number of carbon atoms per nitrogen atom denoted C.sub.B=C.sub.C−1; from 0 to 25% by weight of a semi-crystalline aliphatic polyamide denoted A having an average number of carbon atoms per nitrogen atom denoted C.sub.A=C.sub.B−1; from 0 to 45% by weight of at least one impact modifier, from 0 to 20% by weight of at least one plasticizer, from 0 to 2% by weight of at least one additive, the sum of the constituents being equal to 100%.

8. The multilayer tubular structure (MLT) according to claim 1, wherein the recycled material comes from a single layer and/or multilayer tube selected from a crushed single layer and/or multilayer tube, a crushed and recompounded single layer and/or multilayer tube, and a crushed, recompounded and reformulated single layer and/or multilayer tube.

9. The multilayer tubular structure (MLT) according to claim 8, wherein said composition of layer (1) is free of plasticizer and/or impact modifier and said recycled material comes from a single layer and/or multilayer tube selected from a crushed single layer and/or multilayer tube, a crushed and recompounded single layer and/or multilayer tube, and a crushed, recompounded and reformulated single layer and/or multilayer tube.

10. The multilayer tubular structure (MLT) according to claim 8, wherein said composition of layer (1) comprises at least one compound selected from a plasticizer, an impact modifier and an additive, and said recycled material comes from a single layer and/or multilayer tube selected from a crushed, then recompounded and reformulated single layer and/or multilayer tube.

11. The multilayer tubular structure (MLT) according to claim 1, wherein the fluid transported by said single layer and/or multilayer tube is the same as that of said multilayer tubular structure (MLT).

12. The multilayer tubular structure (MLT) according to claim 1, wherein the fluid transported by said single layer and/or multilayer tube is different from that of said multilayer tubular structure.

13. The multilayer tubular structure (MLT) according to claim 1, wherein the layer (2) consists of a composition comprising: at least 50% by weight of at least one semi-crystalline aliphatic polyamide denoted D having an average number of carbon atoms per nitrogen atom denoted C.sub.D comprised from 6 to 18; from 0 to 50% by weight of at least one semi-crystalline aliphatic polyamide denoted E and having an average number of carbon atoms per nitrogen atom denoted C.sub.E=C.sub.D−1; from 0 to 50% by weight of a semi-crystalline aliphatic polyamide denoted F having an average number of carbon atoms per nitrogen atom denoted C.sub.F=C.sub.E−1; from 3 to 45% by weight of at least one impact modifier, from 0 to 20% by weight of at least one plasticizer, from 0 to 2% by weight of at least one additive, from 0 to 35% of at least one antistatic filler, the sum of the constituents being equal to 100%.

14. The multilayer tubular structure (MLT) according to claim 13, wherein said composition of said layer (1) is free of polyamides denoted A and B and said composition of said layer (2) comprises polyamides selected from those denoted E, F and a mixture thereof.

15. The multilayer tubular structure (MLT) according to claim 14, wherein said composition of said layer (1) comprises polyamides selected from those denoted A, B and a mixture thereof, and said composition of said layer (2) is free of polyamides denoted E and F.

16. The multilayer tubular structure (MLT) according to claim 13, wherein layer (1) comes from a single layer recycled tube.

17. The multilayer tubular structure (MLT) according to claim 13, wherein layer (1) comes from a multilayer recycled tube.

18. The multilayer tubular structure (MLT) according to claim 1, wherein the Tm of the predominant semi-crystalline aliphatic polyamide of layer (1) is ≤225° C., as determined by DSC according to standard ISO 11357-3:2013, at a heating rate of 20 K/min.

19. The multilayer tubular structure (MLT) according to claim 1, wherein the predominant semi-crystalline aliphatic polyamide of layer (1) has a crystallization enthalpy 25 J/g, as determined by DSC according to standard ISO 11357-3:2013 at a heating rate of 20 K/min.

20. The multilayer tubular structure (MLT) according to claim 1, wherein the MLT consists of three layers with the following structure: (2)//(1)//(2).

Description

EXAMPLES

[0317] The following resins were used in the various compositions of the invention:

[0318] PA11: Polyamide 11 of Mn (number-average molecular mass) 29000. The melting temperature is 190° C.; its melting enthalpy is 56 kJ/m2. The composition of this PA11 comprises 0.25% (+/−0.05%) of H3PO4.

[0319] PA12: Polyamide 12 of Mn (number-average molecular mass) 35000. The melting temperature is 178° C.; its melting enthalpy is 54 kJ/m2

[0320] PA12-B: Polyamide 12 of Mn (number-average molecular mass) 41000. The melting temperature is 178° C.; its melting enthalpy is 54 kJ/m2

[0321] PA1012: Polyamide 1012 of Mn (number-average molecular mass) 27000. The melting temperature is 190° C.; its melting enthalpy is 57 kJ/m2

[0322] PA612: Polyamide 612 of Mn (number-average molecular mass) 29000. The melting temperature is 218° C.; its melting enthalpy is 67 kJ/m2

[0323] PA610: Polyamide 610 of Mn (number-average molecular mass) 30000. The melting temperature is 223° C.; its melting enthalpy is 61 kJ/m2

[0324] PA6: Polyamide 6 of Mn (number-average molecular mass) 28000. The melting temperature is 220° C.; its melting enthalpy is 68 kJ/m2

[0325] The melting temperature and the melting enthalpy were determined according to standard ISO 11357-3:2013.

[0326] The following additives, plasticizers and impact modifiers were used in the compositions of the invention:

[0327] stabilizer: stabilizer consisting of 80% of phenol Lowinox 44625 from Great Lakes, 20% of phosphite Irgafos 168 from Ciba

[0328] BBSA: BBSA (butyl benzene sulfonamide) plasticizer,

[0329] Imod=generically refers to a polyolefin type impact modifier or the like, such as among others PEBA (polyether block amide), core-shells, silicons . . .

[0330] Imod1: refers to an EPR functionalized by a reactive group with anhydride function (at 0.5-1% by mass), of MFI 9 (at 230° C., below) 10 kg, of Exxellor VA1801 type from Exxon.

[0331] Imod2: impact modifier of ethylene/ethyl acrylate/anhydride type with a mass ratio of 68.5/30/1.5 and MFI 6 at 190° C. under 2.16 kg.

[0332] Imod3: impact modifier of ethylene/butyl acrylate/anhydride type with a mass ratio of 79/18/3 and MFI 5 at 190° C. under 2.16 kg.

[0333] The following compositions were used to produce the tubes according to the invention:

[0334] In the entire description, all the percentages are given in weight.

[0335] In the case of compositions referred to as “recy”, “recy2” and “recy3” used for layer (1) of the tubes of the invention and counter-example tubes, protocols to simulate an aged tube were used:

[0336] Protocol A: The tube is (artificially) aged according to an easily reproducible model protocol that consists of placing it in air (in the presence of oxygen) at 150° C. for 96 hours (4 days), in order to thermo-oxidate it. This aging model is representative of the average thermo-oxidation undergone by the tubes in 10 years of service in a vehicle next to a warm engine.

[0337] This tube aged according to this protocol (PA11-recy) was crushed and the granules obtained were used for manufacturing recycled layer (1) of example 9 and compared to a tube (example 10) whose recycled layer (1) comes from granules from a tube of PA11PL

[0338] The results obtained on shock, aging, flexural modulus, adhesion and elongation show that protocol A is representative of a recrushed gasoline tube.

[0339] Specific protocols used during the (re)compounding of the aged tube.

[0340] After aging, the crushed tube can, in certain cases, be recompounded according to two protocols:

[0341] Protocol B: the crushed tube is recompounded on a Coperion/Werner 40 mm twin-screw extruder with a setpoint of 70 kgh, 300 rpm, 270° C., with a degassing of −100 mmHg.

[0342] Protocol B2: the crushed tube is recompounded on a Coperion/Werner 40 mm twin-screw extruder with a setpoint of 70 kgh, 300 rpm, 270° C., with a strong degassing of −660 mmHg.

[0343] The various compositions used for the preparation of the tubes of the invention are as follows:

[0344] PA11PL=PA11+7% BBSA+1% stabilizer

[0345] PA12PL=PA12+12% BBSA+1% stabilizer

[0346] PA11PL-recy=tube of PA11PL aged according to protocol A, recrushed, to then be recycled.

[0347] PA11-recy-car=tube of PA11PL from a gasoline line of a Toyota vehicle, that is 10 years old and recrushed.

[0348] PA11PL-recy2=tube of PA11PL aged according to protocol A, recrushed, recompounded according to protocol B2, with, during this recompounding, addition of 7% of BBSA+0.5% of stabilizer, to then be recycled

[0349] PA11PL-recy+50% PA12PL-recy=a 50/50 mixture of granules of PA11PL-recy and PA12PL-recy.

[0350] PA12PL-recy=tube of PA12PL aged according to protocol A, recrushed, to then be recycled.

[0351] PA12imod1=PA12+6% imod1+8% BBSA+1% stabilizer

[0352] PA11imod2=PA11+6% imod2+5% BBSA+1% stabilizer

[0353] PA1012PL4=PA1012+12% BBSA+1% stabilizer

[0354] 1012-recy=1012-recy=tube of PA1012PL4 aged according to protocol A, recrushed, to then be recycled

[0355] 1012-recy2=tube of PA1012PL4 aged according to protocol A, recrushed, recompounded according to protocol B2, with, during this recompounding, addition of 12% of BBSA+0.5% of stabilizer, to then be recycled

[0356] PA11PL4=PA11+12% BBSA+1% stabilizer

[0357] PA12HIP-recy3=tube of PA12HIPHL aged according to protocol A, recrushed, recompounded according to protocol B, with, during this recompounding, addition of 6% imod1, 9% BBSA and 1% of stabilizer; being then intended to be recycled

[0358] 11NX3=PA11+imod2 10% +PA610 5%+PA6 5%+BBSA 4%+stabilizer 1% 11NX3-recy2=tube of 11NX3 aged according to protocol A, recrushed, recompounded according to protocol B2, recompounding with strong degassing, with, during this recompounding, addition of 3% of BBSA and 0.5% of stabilizer

[0359] PA11-recyNX3=tube of PA11PL aged according to protocol A, recrushed, recompounded according to protocol B2, with, during this recompounding, addition of imod2 10%+PA610 5%+PA6 5%+BBSA 4%+stabilizer 1%, to then be recycled.

[0360] PA11PL-recy+50%PA11PL=a 50/50 mixture of PA11PL-recy and PA11PL granules, recycled material and virgin material

[0361] PA612imod1=PA612+12% imod1+10% BBSA+1% stab

[0362] PA612-recy2=tube of PA612imod1 aged according to protocol A, recrushed, recompounded according to protocol B, with, during the recompounding, the addition of 10% of BBSA+0.5% of stabilizer, to then be recycled PA612-recy3-adh=tube of PA612imod1 aged according to protocol A, recrushed, recompounded according to protocol B, with, during this recompounding step, addition of PA6 up to 20% and 10% BBSA and 0.5% stabilizer; to then be recycled PA12HIPHL=PA12+6% imod1+10% BBSA+1% stabilizer PA12HIPHL-recy=tube of PA12HIPHL aged according to protocol A, recrushed, to then be recycled

[0363] PA12HIPHL-recy2=tube of PA12HIPHL aged according to protocol A, recrushed, recompounded according to protocol B, with, during this recompounding, addition of 10% of BBSA+0.5% of stabilizer, to then be recycled

[0364] PA12HIP-recy3=tube of PA12HIPHL aged according to protocol A, recrushed, recompounded according to protocol B, with, during this recompounding, addition of 6% imod1, 9% BBSA and 1% of stabilizer; being then intended to be recycled

[0365] MLT-cx11-recy =tube of MLT (11NX3//OHhi//11NX3 45//15//40%) aged according to protocol A, recrushed, recompounded according to protocol B, to then be recycled

[0366] MLT-cx11-recy+20% MLTcx31-recy=is a mixture of 80% of MLT-cx11-recy and 20% of MLT-cx31-recy

[0367] MLT-cx31-recy=tube of MLT (PA12H12//PA11-recyNX3//PPA9T 15/60/25%) aged according to protocol A, recrushed, recompounded according to protocol B, to then be recycled

[0368] PA12HI2=PA12-B+10% imod1+5% of BBSA+1% of stabilizer

[0369] PA612-imod-adh=PA612+15% imod1+20% of PA6+1% of stabilizer

[0370] PA612-np=PA612+15% imod1 PA6+1% of stabilizer

[0371] MLT-cx51-recy=tube of MLT cx51 aged according to protocol A, recrushed, recompounded according to protocol B, to then be recycled

[0372] MLT-cx51-recy-adh=tube of MLT cx51 aged according to protocol A, recrushed, recompounded according to protocol B, with, during this recompounding, addition of 20% of PA6; to then be recycled

[0373] MLT-cx61-recy=tube of MLT cx61 aged according to protocol A, recrushed, recompounded according to protocol B, with, during this recompounding, addition of 20% of PA6; to then be recycled

[0374] PA12im-adh=PA12+6% imod1+6% BBSA+20% PA612+1% stab

[0375] OHhi=impact modified EVOH, marketed under the name of EVAL LA170B by Eval-Kuraray

[0376] EVOH32=EVOH with 32% ethylene, marketed by Eval under the name of Eval FP101B

[0377] These compositions are manufactured by conventional compounding in a co-rotating twin screw extruder of Coperion 40 type, at 300 rpm, at 270° C. (or at 300° C. when the ingredients have a melting point higher than 260° C.).

[0378] Multi-Layer Tubes of the Invention:

[0379] The layers are described from the outside inwards, followed by their respective thicknesses indicated as a %; the dimension of the tubes is 8*1 mm

[0380] Preparation of multilayer structures (tubes):

[0381] The multi-layer tubes are manufactured by co-extrusion. An industrial Maillefer multilayer extrusion line is used, equipped with 5 extruders, connected to a multilayer extrusion head with spiral mandrels.

[0382] The screws used are extrusion monoscrews having screw profiles adapted to polyamides. In addition to the 5 extruders and the multilayer extrusion head, the extrusion line comprises:

[0383] a die-punch assembly, located at the end of the coextrusion head; the internal diameter of the die and the external diameter of the punch are selected according to the structure to be produced and the materials of which it is composed, as well as the dimensions of the tube and the line speed;

[0384] a vacuum tank with an adjustable vacuum level. In this tank water circulates generally maintained at 20° C., in which a gauge is submerged making it possible to shape the tube to its final dimensions. The diameter of the gauge is adapted to the dimensions of the tube to be produced, typically from 8.5 to 10 mm for a tube with an external diameter of 8 mm and a thickness of 1 mm; a succession of cooling tanks in which water is maintained at around 20° C., allowing the tube to be cooled along the path from the head to the drawing bench;

[0385] a diameter meter;

[0386] a drawing bench.

[0387] The configuration with 5 extruders is used to produce the tubes ranging from 2 layers to 5 layers (and also single layer tubes). In the case of structures whose number of layers is less than 5, several extruders are then fed with the same material.

[0388] Before the tests, in order to ensure the best properties for the tube and good extrusion quality, it is verified that the extruded materials have a residual moisture content before extrusion of less than 0.08%. Otherwise, an additional step of drying the material before the tests, generally in a vacuum dryer, is carried out overnight at 80° C.

[0389] The tubes, which satisfy the characteristics disclosed in the present patent application, were removed, after stabilization of the extrusion parameters, the dimensions of the tubes in question no longer changing over time. The diameter is controlled by a laser diameter meter installed at the end of the line.

[0390] The line speed is typically 20 m/min. It generally ranges from 5 to 100 m/min.

[0391] The screw speed of the extruders depends on the thickness of the layer and on the diameter of the screw as is known to those skilled in the art.

[0392] In general, the temperatures of the extruders and of the tools (head and connector) must be adjusted so as to be sufficiently higher than the melting temperature of the compositions in question, so that they remain in the molten state, thus preventing them from solidifying and jamming the machine.

[0393] The multi-layer tubes manufactured by extrusion above were then assessed according to several criteria:

[0394] Flex.: refers to the flexural modulus measured according to ISO178 at 23° C. on a tube conditioned with a humidity balance of 50% and at 23° C.

[0395] “+” is used to denote a flexibility that can be qualified as “good”, which corresponds to <=1000 MPa and >500 MPa

[0396] “++” is used to denote a flexibility that can be qualified as “very good”, which corresponds to <=500 MPa and >250 MPa

[0397] Shock: refers to the VW-40° C. type shock standard VW TL52435 2010

[0398] “++” is used to denote a shock performance that can be qualified as “very good”, which corresponds to <=10% breakage.

[0399] “+” is used to denote a shock performance that can be qualified as “good”, which corresponds to <=25% breakage and >10% breakage

[0400] “−” is used to denote a shock performance that can be qualified as “quite poor”, which corresponds to <=75% breakage and >25% breakage

[0401] “−−” is used to denote a shock performance that can be qualified as “very poor”, which corresponds to >75%

[0402] Aging: this relates to durability, in other words, this refers to the resistance of the tube to oxidative aging in warm air. The tube is aged in air at 150° C., then it is shocked with a shock according to standard DIN 73378, this shock being performed at −40° C., the half-life is indicated (in hour) which corresponds to the time after which 50% of the tubes tested break. A qualitative comment accompanies this value.

[0403] “++” is used to denote a durability that can be qualified as “very good”, which corresponds to >=200 h of half-life.

[0404] “+” is used to denote a durability (thermo-oxidative aging resistance) that can be qualified as “good”, which corresponds to >=100 h of half-life (and <200 h)

[0405] “+−”, is used to denote a durability (thermo-oxidative aging resistance) that can be qualified as “acceptable”, which corresponds to >=50 h of half-life (and <100 h)

[0406] “−” is used to denote a durability (thermo-oxidative aging resistance) that can be qualified as “poor”, which corresponds to <50 h

[0407] In the case where a half-life number is given to show slight differences, this number is rounded to the nearest 25-hour increment, to take into account significant figures, related to the accuracy of the evaluation.

[0408] Adh.: this is the adhesive strength. It reflects the peel strength, expressed in N/cm, and measured on the tube with a diameter of 8 mm and thickness of 1 mm having undergone conditioning for >=15 days at 50% relative humidity at 23° C., such that the humidity balance is achieved in the sample.

[0409] The value given relates to the weakest interface, that is to say the least adherent of the multilayer, where there is therefore the greatest risk of detachment. The peeling is performed at the interface by pulling one of the parts at an angle of 90° and at a speed of 50 mm/min according to the following method.

[0410] A 9 mm wide sample strip of a tube is cut. This strip is therefore in the shape of a tile and still has all the layers of the original tube. The two layers of the interface to be assessed begin to be separated using a knife. Each of the thus separated layers is placed in the jaws of a universal testing machine. The peeling is carried out by pulling these 2 layers on either side at 180 degrees and at a speed of 50 mm/min. The strip, and therefore the interface, is maintained at 90 degrees relative to the direction of pulling.

[0411] The following is noted:

[0412] +++: very good, >50

[0413] ++: good, >20 and <=50

[0414] +: quite good (acceptable), >10 and <=20

[0415] −: poor, <=10

[0416] EI.%: this is the elongation at the rupture point performed according to standard ISO R527 except that it is measured on a tube with a diameter of 8 mm and thickness of 1 mm. The sample is ISO-conditioned, that is a conditioning of >=15 days at 50% relative humidity at 23° C. such that the humidity balance is achieved in the sample.

[0417] The following is noted:

[0418] +++: very good, >=200% elongation

[0419] ++: good, >=100 and <200% elongation

[0420] +: unsatisfactory: <100% elongation

[0421] The results are given in Table 1.

TABLE-US-00001 TABLE 1 Structure and thickness of layers (as a % of total thickness) Shock Aging Flex. Adh. El. % Example Ex1 PA12imod1 // PA12PL-recy // ++ ++ + +++ +++ PA12imod1 15/70/15% Ex2 PA12imod1 // PA11PL-recy // ++ ++ + +++ +++ PA12imod1 15/70/15% Ex3 PA12imod1 // PA11PL-recy + ++ ++ + +++ +++ 50% PA12PL-recy // PA12imod1 15/70/15% Ex4 PA11imod2 // PA11PL-recy // ++ ++ + +++ +++ PA11imod2 15/70/15% Ex5 PA11imod2 // PA12PL-recy // ++ ++ + +++ +++ PA11imod2 15/70/15% Ex6 PA12imod1 // 1012-recy // ++ ++ + +++ +++ PA12imod1 15/70/15% Ex7 PA11PL // 1012-recy // PA11PL ++ ++ + +++ +++ 15/70/15% Ex8 PA11PL4 // 1012-recy2 // ++ ++ ++ +++ +++ PA11PL4 15/70/15% Ex9 PA11PL // PA11PL-recy // PA11PL ++ + + +++ +++ 15/70/15% Ex10 PA11PL // PA11PL-recy-car // ++ + + +++ +++ PA11PL 15/70/15% Ex11 PA11PL // PA11PL-recy2 // PA11PL ++ + ++ +++ +++ 15/70/15% Ex12 PA11PL // PA11PL-recyNX3 // ++ + ++ +++ +++ PA11PL 15/70/15% Ex13 PA11PL // PA11PL-recy + ++ + + +++ +++ 50% PA11PL// PA11PL 15/70/15% Ex14 PA11PL // PA11PL-recy + ++ + + +++ +++ 50% PA12PL-recy// PA11PL 15/70/15% Ex15 PA11PL // PA12PL-recy // PA11PL ++ ++ + +++ +++ 15/70/15% Ex16 PA12imod1 // PA12HIPHL-recy // ++ ++ + +++ +++ PA12imod1 15/70/15% Ex17 PA12imod1 // PA12HIPHL-recy2 // ++ ++ ++ +++ +++ PA12imod1 15/70/15% Ex18 PA12imod1 // PA12HIP-recy3 // ++ ++ ++ +++ +++ PA12imod1 15/70/15% Ex19 PA612imod1 // PA12HIP-recy3 // ++ ++ ++ +++ +++ PA12imod1 15/70/15% Ex20 PA12imod1 // PA612-recy2 // ++ ++ ++ + +++ PA12imod1 15/70/15% Ex21 PA12imod1 // PA612-recy3-adh // ++ ++ ++ ++ +++ PA12imod1 15/70/15% Ex22 PA12imod1 // PA11-recyNX3 // ++ ++ NT ++ +++ OHhi // 11NX3 15/30/15/40% Ex23 11NX3 // PA11-recyNX3 // OHhi // ++ ++ NT ++ +++ 11NX3 15/30/15/40% Ex24 11NX3 //MLT-cx11-recy// OHhi // ++ ++ NT ++ +++ 11NX3 15/30/15/40% Ex25 PA12imod1 //MLT-cx11-recy// OHhi ++ ++ NT ++ +++ // 11NX3 15/30/15/40% Ex26 PA12imod1 //MLT-cx11-recy// OHhi ++ ++ NT ++ +++ // MLT-cx11-recy // PA12imod1 30/15/15/15/25% Ex27 PA12imod1 // MLT-cx51-recy // ++ ++ NT + +++ OHhi // PA612-imod-adh//PA612- np 40/15/15/10/20% Ex28 PA12im-adh // MLT-cx51-recy-adh ++ ++ NT ++ +++ // OHhi // PA612-imod-adh 40/15/15/10/20% Ex29 PA12imod1 // MLT-cx61-recy // ++ ++ NT + +++ PA612imod1 // MLT-cx61-recy // PA12imod1 10/15/50/15/10% Ex30 PA12im-adh // MLT-cx61-recy // ++ ++ NT ++ +++ PA612imod1 // MLT-cx61-recy // PA12im-adh 10/15/50/15/10% counter examples cx1 PA12PL // PA12HIPHL-recy // − − + +++ +++ PA12PL 15/70/15% cx2 PA12PL // PA12PL-recy // PA12PL −− − + +++ +++ 15/70/15% cx3 PA12PL // PA11PL-recy // PA12PL − − + +++ +++ 15/70/15% cx4 Single layer PA12PL-recy −− − + NT + cx5 single layer PA11PL-recy + − ++ NT + cx6 Single layer PA11PL-recy2 ++ − ++ NT ++ cx7 Single layer PA12HIP-recy3 + − ++ NT ++ cx8 Single layer 1012-recy − − + NT + NT: Not tested