spore: profile
id: self-reinforced-composites
spore_version: 0.2
family: glass-and-composites
name: Self-reinforced polymer composites and aramid composites
abbreviation: SRC
role: structural composite
category: composites
type: carbon-fiber-reinforced
summary: |
  Self-reinforced composites (SRC) are made from one polymer in two forms: oriented fibres or tapes are pressed so that only their outer skin melts and bonds the rest, giving a laminate with a matrix and a reinforcement of the same chemistry. The UHMWPE SRC in the sources read here, made from Dyneema SGX fibre, reaches 174.3 MPa along the fibres at 155 C and 25 MPa, at about 1.0 g/cm3. Para-aramid fibre (Kevlar type) is a separate, high-strength reinforcement with a density of 1.44 g/cm3 and a yarn tensile strength of 3000 MPa, and it is used in aramid laminates with epoxy, vinyl ester and thermoplastic matrices. Most numbers in this file are for the fibre or the matrix resin; laminate values for the aramid systems were not read.
best_for: 'Light, recyclable structures where one polymer family is wanted: UHMWPE SRC gives about 1.0 g/cm3 with 174.3 MPa along the fibres'
weakest_at: 'Strength across the fibres: 7.7 MPa transverse against 174.3 MPa along them, and the polyolefin SRC softens near 135 C in its unfilled matrix'
identity:
  formula: Ultra-high molecular weight polyethylene (UHMWPE) fibre, Dyneema SGX, hot-compacted into a single-polymer composite; para-aramid fibre (wholly aromatic polyamide, Kevlar type) in aramid laminates
  source: srpc-2021
  where: 'Section 2.1, Self-Reinforced Composite (SRC) Preparation: UHMWPE fibres from SGX (DSM Dyneema) with a linear density of 220 dtex; Dupont Kevlar guide, Section I, what is Kevlar'
tags:
  environments:
    - deep-space
  stresses:
    - uv
    - extreme-heat
  applications:
    - structures
    - radiation-shielding
properties:
  - benchmark: ultimate_tensile_strength
    label: Tensile strength along the fibres, UHMWPE SRC, 155 C and 25 MPa, regime 1
    value: 174.3
    unit: MPa
    scope: material
    conditions:
      fibre: UHMWPE, SGX (DSM Dyneema), 220 dtex
      form: self-reinforced composite, hot compacted, longitudinal specimens
      temperature: 155 C compaction
      pressure: 25 MPa compaction
      process: regime 1 as printed in the table
    method: Ultimate tensile strength printed in Table 2, column UTS long, row 155 C, 25 MPa, regime 1
    status: ground
    source: srpc-2021
    where: Table 2, row 155 C 25 MPa regime 1, column UTS long
  - benchmark: ultimate_tensile_strength
    label: Tensile strength across the fibres, UHMWPE SRC, 155 C and 25 MPa, regime 1
    value: 7.7
    unit: MPa
    scope: material
    conditions:
      fibre: UHMWPE, SGX (DSM Dyneema), 220 dtex
      form: self-reinforced composite, hot compacted, transverse specimens
      temperature: 155 C compaction
      pressure: 25 MPa compaction
      process: regime 1 as printed in the table
    method: Ultimate tensile strength printed in Table 2, column UTS trans, row 155 C, 25 MPa, regime 1
    status: ground
    source: srpc-2021
    where: Table 2, row 155 C 25 MPa regime 1, column UTS trans
  - benchmark: flexural_strength
    label: Flexural strength, UHMWPE SRC, 155 C end of the range
    value: 110.2
    unit: MPa
    scope: material
    conditions:
      fibre: UHMWPE, SGX (DSM Dyneema)
      form: self-reinforced composite, hot compacted
      temperature: 155 C compaction (lower end of the range)
      pressure: 25 MPa compaction
    method: Value printed in the text as the lower end of a range, with the 1.5 MPa standard deviation printed beside it; the paper says the strength rises with compaction temperature
    status: ground
    source: srpc-2020
    where: Results, paragraph on flexural strength and flexural modulus (Figure 4)
  - benchmark: flexural_strength
    label: Flexural strength, UHMWPE SRC, 170 C end of the range
    value: 117.3
    unit: MPa
    scope: material
    conditions:
      fibre: UHMWPE, SGX (DSM Dyneema)
      form: self-reinforced composite, hot compacted
      temperature: 170 C compaction (upper end of the range)
      pressure: 25 MPa compaction
    method: Value printed in the text as the upper end of a range, with the 1.7 MPa standard deviation printed beside it
    status: ground
    source: srpc-2020
    where: Results, paragraph on flexural strength and flexural modulus (Figure 4)
  - benchmark: flexural_modulus
    label: Flexural modulus, UHMWPE SRC, 155 C end of the range
    value: 37.7
    unit: GPa
    scope: material
    conditions:
      fibre: UHMWPE, SGX (DSM Dyneema)
      form: self-reinforced composite, hot compacted
      temperature: 155 C compaction
      pressure: 25 MPa compaction
    method: Value printed in the text with the 1.8 GPa standard deviation; the paper says the modulus falls as compaction temperature rises
    status: ground
    source: srpc-2020
    where: Results, paragraph on flexural strength and flexural modulus (Figure 4)
  - benchmark: flexural_modulus
    label: Flexural modulus, UHMWPE SRC, 170 C end of the range
    value: 18
    unit: GPa
    scope: material
    conditions:
      fibre: UHMWPE, SGX (DSM Dyneema)
      form: self-reinforced composite, hot compacted
      temperature: 170 C compaction
      pressure: 25 MPa compaction
    method: Value printed in the text with the 1.4 GPa standard deviation
    status: ground
    source: srpc-2020
    where: Results, paragraph on flexural strength and flexural modulus (Figure 4)
  - benchmark: shear_strength
    label: Single lap shear strength, UHMWPE SRC, 155 C and 25 MPa
    value: 2.1
    unit: MPa
    scope: material
    conditions:
      fibre: UHMWPE, SGX (DSM Dyneema)
      form: self-reinforced composite against isotropic UHMWPE, hot compacted
      temperature: 155 C compaction
      pressure: 25 MPa compaction
    method: Value printed in Table 1 with the standard deviation 0.10 MPa; shear strength is not a canonical name, so the name is kept as shear_strength
    status: ground
    source: srpc-2020
    where: Table 1, row 155, column Shear Strength at 25 MPa
  - benchmark: shear_strength
    label: Single lap shear strength, UHMWPE SRC, 170 C and 25 MPa
    value: 3.8
    unit: MPa
    scope: material
    conditions:
      fibre: UHMWPE, SGX (DSM Dyneema)
      form: self-reinforced composite against isotropic UHMWPE, hot compacted
      temperature: 170 C compaction
      pressure: 25 MPa compaction
    method: Value printed in Table 1 with the standard deviation 0.14 MPa; the paper reports shear strength rising with compaction temperature at 25 MPa
    status: ground
    source: srpc-2020
    where: Table 1, row 170, column Shear Strength at 25 MPa
  - benchmark: density
    label: Density of UHMWPE fibre reinforced composites, approximate
    value: 1
    unit: g/cm3
    scope: material
    conditions:
      basis: approximate value stated for UHMWPE SRCs, compared with carbon or glass composites at 1.8 to 2.5 g/cm3
      temperature: not stated
    method: Approximate figure printed in the introduction; not a measured value reported in the paper
    status: ground
    source: srpc-2021
    where: Introduction, paragraph on the lower density of UHMWPE SRCs
  - benchmark: crystallinity
    label: Crystallinity of UHMWPE SRC, 155 C and 25 MPa
    value: 92
    unit: '%'
    scope: material
    conditions:
      fibre: UHMWPE, SGX (DSM Dyneema)
      temperature: 155 C compaction
      pressure: 25 MPa compaction
      method_of_measure: DSC melting enthalpy against 291 J/g for 100 percent crystalline UHMWPE
    method: Value printed in Table 1 and the text, with standard deviation 1.1 percent; crystallinity is not a canonical name, so it is kept as crystallinity
    status: ground
    source: srpc-2020
    where: Results, DSC paragraph, and Table 1, row 155 at 25 MPa
  - benchmark: crystallinity
    label: Crystallinity of UHMWPE SRC, 170 C and 25 MPa
    value: 69
    unit: '%'
    scope: material
    conditions:
      fibre: UHMWPE, SGX (DSM Dyneema)
      temperature: 170 C compaction
      pressure: 25 MPa compaction
      method_of_measure: DSC melting enthalpy against 291 J/g for 100 percent crystalline UHMWPE
    method: Value printed in Table 1 and the text, with standard deviation 1.2 percent
    status: ground
    source: srpc-2020
    where: Results, DSC paragraph, and Table 1, row 170 at 25 MPa
  - benchmark: density
    label: Density of unfilled UHMW-PE sheet (matrix grade)
    value: 0.93
    unit: g/cc
    scope: material
    conditions:
      grade: TIVAR 1000, unfilled UHMW-PE sheet
      temperature: not stated
    method: Specific gravity printed in the datasheet, ASTM D792; shown as a matrix reference, not as the SRC density
    status: ground
    source: tivar-1000
    where: Physical Properties table, row Specific Gravity
  - benchmark: melting_point
    label: Melting point of unfilled UHMW-PE, DSC peak (matrix grade)
    value: 135
    unit: C
    scope: material
    conditions:
      grade: TIVAR 1000, unfilled UHMW-PE sheet
      basis: crystalline peak, ASTM D3418
    method: Value printed in the datasheet as 135 C (275 F); the test is a DSC peak
    status: ground
    source: tivar-1000
    where: Physical Properties table, row Melting Point, Crystalline Peak
  - benchmark: max_service_temp
    label: Maximum service temperature in air, unfilled UHMW-PE (matrix grade)
    value: 82.2
    unit: C
    scope: material
    conditions:
      grade: TIVAR 1000, unfilled UHMW-PE sheet
      atmosphere: air
    method: Value printed as 82.2 C (180 F) in the datasheet, a service limit for the matrix polymer
    status: ground
    source: tivar-1000
    where: Physical Properties table, row Maximum Service Temperature, Air
  - benchmark: ultimate_tensile_strength
    label: Tensile strength, unfilled UHMW-PE sheet (matrix grade)
    value: 40
    unit: MPa
    scope: material
    conditions:
      grade: TIVAR 1000, unfilled UHMW-PE sheet
      temperature: room temperature (not stated)
      test: ASTM D638
    method: Value printed in the datasheet as 40.0 MPa (5800 psi), with the ASTM D638 method
    status: ground
    source: tivar-1000
    where: Mechanical Properties table, row Tensile Strength
  - benchmark: elongation
    label: Elongation at break, unfilled UHMW-PE sheet (matrix grade)
    value: 300
    unit: '%'
    scope: material
    conditions:
      grade: TIVAR 1000, unfilled UHMW-PE sheet
      test: ASTM D638
    method: Value printed in the datasheet, ASTM D638
    status: ground
    source: tivar-1000
    where: Mechanical Properties table, row Elongation at Break
  - benchmark: elastic_modulus
    label: Tensile modulus, unfilled UHMW-PE sheet (matrix grade)
    value: 0.552
    unit: GPa
    scope: material
    conditions:
      grade: TIVAR 1000, unfilled UHMW-PE sheet
      test: ASTM D638
    method: Value printed in the datasheet as 0.552 GPa (80.0 ksi), ASTM D638
    status: ground
    source: tivar-1000
    where: Mechanical Properties table, row Tensile Modulus
  - benchmark: moisture_absorption
    label: Water absorption of unfilled UHMW-PE, 24 hour immersion (matrix grade)
    value: 0.01
    unit: '%'
    scope: material
    conditions:
      grade: TIVAR 1000, unfilled UHMW-PE sheet
      test: 24 hour immersion, ASTM D570
      note: printed as less than or equal to 0.010 percent, so the value is an upper limit
    method: Upper limit printed in the datasheet; the saturation value is printed with the same upper limit
    status: ground
    source: tivar-1000
    where: Physical Properties table, row Water Absorption, 24 hr immersion
  - benchmark: density
    label: Density of polypropylene used for self-reinforced tapes
    value: 910
    unit: kg/m3
    scope: material
    conditions:
      grade: PP homopolymer, weight average molecular weight 360000 g/mol
      temperature: not stated
    method: Value printed in the materials section of the paper for the PP homopolymer tapes used to make single-polymer composites
    status: ground
    source: foster-2016
    where: Materials section, first paragraph
  - benchmark: melting_point
    label: Unconstrained peak melting point of the polypropylene tapes
    value: 163
    unit: C
    scope: material
    conditions:
      grade: PP homopolymer, weight average molecular weight 360000 g/mol
      basis: unconstrained peak melting point, before compaction
    method: Value printed in the materials section; the compaction window in the paper is set just below and above the melting range
    status: ground
    source: foster-2016
    where: Materials section, first paragraph
  - benchmark: compaction_peak_temperature
    label: Hot compaction temperature at the peak of property for PP tapes
    value: 190
    unit: C
    scope: material
    conditions:
      grade: PP homopolymer tapes, draw ratios studied in the paper
      pressure: hot press, 4.9 MPa on the sample frame
      basis: peak in the tensile properties, for all draw ratios except the lowest
    method: Approximate peak in the properties printed in the results text (about 190 C); the paper reports the Young modulus against compaction temperature in a figure, so only the text value is used
    status: ground
    source: foster-2016
    where: Results, paragraph on the peak in properties at about 190 C
  - benchmark: density
    label: Density of para-aramid yarn, Kevlar 49
    value: 1.44
    unit: g/cm3
    scope: material
    conditions:
      fibre: Kevlar 49 yarn, 1,140 denier
      temperature: not stated
    method: Value printed in the yarn properties table as 0.052 lb/in3, with the g/cm3 value in parentheses
    status: ground
    source: dupont-kevlar-guide
    where: Yarn properties table, row Density, Kevlar 49 column
  - benchmark: ultimate_tensile_strength
    label: Tensile strength of Kevlar 49 yarn, straight test on conditioned yarn
    value: 3000
    unit: MPa
    scope: material
    conditions:
      fibre: Kevlar 49 yarn, 1,140 denier, 768 filaments
      state: conditioned yarn, straight test
      temperature: not stated in the row
    method: Typical value printed in the yarn properties table in MPa, with the 435000 psi figure beside it
    status: ground
    source: dupont-kevlar-guide
    where: Tensile Properties table, row Breaking Strength, MPa, Kevlar 49 column
  - benchmark: elastic_modulus
    label: Tensile modulus of Kevlar 49 yarn
    value: 112400
    unit: MPa
    scope: material
    conditions:
      fibre: Kevlar 49 yarn, 1,140 denier
      state: conditioned yarn, straight test
    method: Typical value printed in the yarn properties table in MPa (112,400 MPa)
    status: ground
    source: dupont-kevlar-guide
    where: Tensile Properties table, row Tensile Modulus, MPa, Kevlar 49 column
  - benchmark: elongation
    label: Elongation at break of Kevlar 49 yarn
    value: 2.4
    unit: '%'
    scope: material
    conditions:
      fibre: Kevlar 49 yarn, 1,140 denier
      state: conditioned yarn, straight test
    method: Typical value printed in the yarn properties table
    status: ground
    source: dupont-kevlar-guide
    where: Tensile Properties table, row Elongation at Break, Kevlar 49 column
  - benchmark: max_service_temp
    label: Recommended maximum temperature for long-term use in air, Kevlar
    value: 149
    value_high: 177
    unit: C
    scope: material
    conditions:
      fibre: Kevlar para-aramid yarn
      atmosphere: air
      duration: long-term use
      unit_in_source: 300 to 350 F
    method: Range printed in the thermal properties table, converted from F as printed (300 to 350 F); the guide gives the range as 149 to 177 C
    status: ground
    source: dupont-kevlar-guide
    where: Thermal Properties table, row Recommended Maximum Temperature Range for Long-Term Use in Air
  - benchmark: decomposition_temperature
    label: Decomposition temperature of Kevlar in air
    value: 427
    value_high: 482
    unit: C
    scope: material
    conditions:
      fibre: Kevlar para-aramid
      atmosphere: air
      rate: depends on the heating rate; typical TGA at 10 C per minute
      unit_in_source: 800 to 900 F
    method: Range printed in the thermal properties table as 427 to 482 C (800 to 900 F); decomposition temperature is not a canonical name
    status: ground
    source: dupont-kevlar-guide
    where: Thermal Properties table, row Decomposition Temperature in Air
  - benchmark: moisture_absorption
    label: Equilibrium moisture content of Kevlar 49 yarn, from bone-dry yarn
    value: 3.5
    unit: '%'
    scope: material
    conditions:
      fibre: Kevlar 49 yarn
      state: equilibrium from bone-dry yarn
      humidity: conditions as printed in the moisture table, not restated in this file
    method: Value printed in the moisture levels table for Kevlar 49, equilibrium from bone-dry yarn
    status: ground
    source: dupont-kevlar-guide
    where: Yarn properties table, Moisture Levels, row Equilibrium from Bone-Dry Yarn, Kevlar 49 column
  - benchmark: cte
    label: Coefficient of thermal expansion of Kevlar 49 yarn, longitudinal direction
    value: -4.9
    unit: ppm/K
    scope: material
    conditions:
      fibre: Kevlar 49 yarn, 1,420 denier
      temperature_range: 25 to 150 C
      unit_in_source: '-4.9 x 10-6 cm/cm/C'
    method: Value printed as -4.9 x 10-6 cm/cm/C in the CTE table, shown here in ppm/K, which has the same value; the guide notes that the CTE depends on measuring technique
    status: ground
    source: dupont-kevlar-guide
    where: Table II-4, Coefficient of Thermal Expansion, Kevlar 49 row
corrosion:
  - environment: UV light exposure of UHMWPE fibre mesh, outdoors and in artificial UV
    headline: UV ageing lowers the breaking strength of UHMWPE mesh more efficiently than salt spray.
    effect: The paper says UV energy activates UHMWPE molecules and causes chain breaking, which lowers the breaking strength more efficiently than salt spray. No retention percentage was read in the text used here.
    rating: moderate
    conditions:
      basis: qualitative statement from the abstract; no retention value read
      material: UHMWPE fibre barrier net (marine service)
    source: mdpi-barrier
    where: Abstract
  - environment: Hot and humid ageing of UHMWPE fibres at 50 C and 93 percent relative humidity
    headline: Humid heat first lowers breaking strength, then the fibres bond into clumps and the strength rises slightly.
    effect: The paper says the breaking strength drops rapidly at first, then rises slightly as the UHMWPE fibres bond into clumps. The acceleration ratio of the test spectrum rises with ageing time.
    rating: moderate
    conditions:
      temperature: 50 C
      humidity: 93 percent relative humidity
      cycle: 10 days per cycle in the chamber
    source: mdpi-barrier
    where: Abstract, and Section 2.2.3, Hygrothermal Aging Experiment
  - environment: Salt spray on UHMWPE fibre mesh, 5 wt percent NaCl at 35 C
    headline: Salt spray is the milder of the marine ageing tests for the UHMWPE mesh, per the paper's comparison with UV.
    effect: The paper finds UV more damaging than salt spray for breaking strength. No salt spray retention value was read.
    rating: low
    conditions:
      electrolyte: 5 wt percent NaCl
      temperature: 35 C
      standard: ISO 4611-2010
      duration: up to 60 days in six 10-day cycles
    source: mdpi-barrier
    where: Abstract; Section 2.2.2, Salt Spray Aging Experiment
  - environment: Heat in nitrogen, para-aramid yarn (Kevlar)
    headline: Kevlar tensile properties are virtually unaffected by 538 C in nitrogen, but it decomposes in air at 427 to 482 C.
    effect: The guide says the tensile properties of Kevlar are virtually unaffected by 1000 F (538 C) in nitrogen. In air the decomposition range is 427 to 482 C, and the recommended long-term use range is 149 to 177 C.
    rating: low
    conditions:
      atmosphere: nitrogen
      temperature: 538 C
    source: dupont-kevlar-guide
    where: Thermal Properties, text on decomposition temperature and effect of elevated temperatures
  - environment: UV light exposure of para-aramid yarn
    headline: Unprotected Kevlar yarn yellows to brown and can lose mechanical properties under extended UV.
    effect: The guide says unprotected yarn tends to discolour from yellow to brown after prolonged exposure, and that extended UV exposure can cause loss of mechanical properties, depending on wavelength, time and intensity. Degradation needs oxygen; moisture does not enhance it. No retention figure was read.
    rating: moderate
    conditions:
      atmosphere: oxygen present
      guidance: keep yarn away from fluorescent lamps and window glass
    source: dupont-kevlar-guide
    where: Section II, Effect of UV Light on Kevlar, and the text before it
  - environment: Strong aqueous acids, bases and sodium hypochlorite on para-aramid yarn
    headline: Kevlar is chemically stable under a wide range of conditions, but strong acids, bases and hypochlorite can degrade it.
    effect: The guide says degradation can occur with certain strong aqueous acids, bases and sodium hypochlorite, particularly over long periods and at elevated temperatures. Table II-3 gives the breaking strength after exposure; its numbers were not used here.
    rating: moderate
    conditions:
      agents: strong aqueous acids, strong bases, sodium hypochlorite
      temperature: elevated temperatures over long periods
    source: dupont-kevlar-guide
    where: Section II, Effect of Chemical Agents on Kevlar, and Table II-3
uses:
  - application: structures
    device: Lightweight self-reinforced UHMWPE composite plates
    example: The UHMWPE SRC is pressed as rectangular plates of 80 by 10 by 2 mm in the work read here. The authors frame SRCs as lightweight, chemically inert alternatives to carbon and glass composites for mechanical use.
    source: srpc-2021
    where: Section 2.1 and Introduction, paragraph on applications requiring chemical inertness
  - application: radiation-shielding
    device: Polyethylene galactic cosmic ray shield (neat polyethylene, not the SRC)
    example: The NASA technical paper tests polyethylene as a shield material. It quotes Shinn et al. as saying polyethylene, with its short nuclear absorption lengths, is an effective shield material.
    source: nasa-tp3473
    where: Introduction, paragraph on hydrogenous shield materials
  - application: structures
    device: Para-aramid fibre in rigid epoxy composites
    example: The guide compares Kevlar with the modulus of an epoxy used in making rigid composites, in its low temperature property discussion. The fibre is used for reinforcement of polymer matrices in these composites.
    source: dupont-kevlar-guide
    where: Section II, low temperature (cryogenic) property text, comparison with epoxy
  - application: structures
    device: Carbon-epoxy laminate with woven aramid layers
    example: A 2024 study adds woven aramid fibre to carbon-epoxy laminates made by vacuum assisted resin infusion, to study the in-plane tensile behaviour. The aramid is treated as a high strain material that improves impact strength.
    source: manipal-carbon-aramid
    where: Abstract
supply:
  - subject: UHMWPE fibre (Dyneema SGX, 220 dtex, 15 to 20 micrometres diameter)
    abundance: 'Not applicable: synthetic polymer fibre; no crustal abundance applies'
    producers: []
    manufacture: The paper names DSM Dyneema, Heerlen, Netherlands, as the source of the SGX fibre used in the SRC work. No production shares by country were read in a fetched source.
    source: srpc-2021
    where: Section 2.1, Self-Reinforced Composite (SRC) Preparation
  - subject: Para-aramid fibre (Kevlar)
    abundance: 'Not applicable: synthetic aromatic polyamide fibre; no crustal abundance applies'
    producers: []
    manufacture: The guide is published by DuPont for Kevlar aramid fibre. No production shares by country were read.
    source: dupont-kevlar-guide
    where: Introduction, What is Kevlar, and the guide cover
risks:
  hazards:
    - text: Para-aramid (Kevlar) fibre dust may form combustible dust concentrations in air if small particles are generated during processing, handling or by other means. The SDS classification is combustible dust, with signal word Warning.
      ghs: []
      source: kevlar-sds
      where: Section 2, hazard identification (product hazard category, combustible dust)
    - text: The Kevlar SDS reports no skin irritation in guinea pigs and an oral LD50 above 7500 mg/kg in rat, and says the polymer is not expected to produce toxic effects. Eye protection with side-shields is recommended.
      ghs: []
      source: kevlar-sds
      where: Section 11, toxicological information, and Section 8, eye protection
    - text: Unfilled UHMW-PE (TIVAR VMX food grade SDS) is not classified under GHS, with no signal word and no hazard statements. The sheet still advises avoiding dust formation.
      ghs: []
      source: tivar-vmx-sds
      where: Section 2, GHS classification; Section 7, handling
    - text: PubChem GHS summary for styrene (CID 7501), a monomer that vinyl ester resins are often diluted with. The vinyl ester formulation used in the sources read here was not published, so this applies to styrene, not to a cured laminate.
      ghs:
        - 'H226: Flammable liquid and vapor'
        - 'H315: Causes skin irritation'
        - 'H319: Causes serious eye irritation'
        - 'H332: Harmful if inhaled'
        - 'H361d: Suspected of damaging the unborn child'
        - 'H372: Causes damage to organs through prolonged or repeated exposure'
      source: pubchem-styrene
      where: GHS Classification, first block of hazard statements for CID 7501
  failure_risks:
    - source: srpc-2021
      where: Table 2, transverse and longitudinal UTS columns
      mode: Loading across the fibres
      trigger: Tension transverse to the fibre direction in a unidirectional SRC
      consequence: The paper gives 4.1 to 16.5 MPa across the fibres, against 67.8 to 174.3 MPa along them. Layup decides how much of the fibre strength a part can use.
      severity: high
    - source: srpc-2020
      where: Results, DSC paragraph, fraction of preserved fibres
      mode: Over-melting of the fibres during hot compaction
      trigger: Compaction at 165 to 170 C at 25 MPa
      consequence: The preserved fibre fraction falls from 88 percent at 155 C to 76 percent at 165 C and 34 percent at 170 C, so the reinforcement is largely lost at the top of the window.
      severity: high
    - source: foster-2016
      where: Results, paragraph on the peak in properties with compaction temperature
      mode: Narrow processing window for polypropylene tapes
      trigger: Compaction temperature away from the optimum near 190 C
      consequence: The paper reports the modulus and strength depend strongly on compaction temperature, and the optimum shifts with draw ratio. Off-optimum compaction gives weaker sheets.
      severity: moderate
    - source: dupont-kevlar-guide
      where: Section II, Effect of UV Light on Kevlar
      mode: Ultraviolet degradation of aramid yarn
      trigger: Extended UV exposure with oxygen present
      consequence: The guide says the yarn discolours and can lose mechanical properties. The fibre must be shielded from UV, and no retention figure is given in the text read.
      severity: moderate
  side_effects:
    - text: Dust from cutting or machining aramid and polyolefin composites can build up and form combustible dust in air. Handling dust is the main practical side effect.
      affects: Workers and workshop air
      source: kevlar-sds
      where: Section 2, combustible dust, and Section 7, handling
  mitigations: []
  handling:
    - text: Avoid dust formation. Keep fibre fly and dust under control by ventilation or vacuum cleaning, not by sweeping.
      source: kevlar-sds
      where: Section 7, handling and storage
    - text: The guide notes exposure limits for para-aramid as respirable fibres at 2 RFP/cc and for dust at 5 mg/m3 (8 and 12 hour TWA, DuPont AEL). Wear safety glasses with side shields and a respirator when limits are exceeded.
      source: kevlar-sds
      where: Section 8, exposure limit values and eye protection
gaps:
  - 'Curv (self-reinforced PP, Propex): no numeric value was read. The UL Prospector datasheet page returned a blocked page, the Index Thermoplastics page returned 403, and search results only gave relative ratings. Density, tensile modulus and strength for Curv are not in this file.'
  - 'Pure PP/PP self-reinforced composites: no product datasheet was reached. The only PP numbers are for PP homopolymer tapes from the 2016 Leeds study (density, melting point, compaction peak).'
  - 'PE/PE commercial composites (Dyneema SRPE sheet grades): no manufacturer datasheet was read. The UHMWPE SRC values come from academic papers on SGX fibre compacted in the lab. Dyneema SK75 fibre values from search snippets were not used.'
  - 'Carbon/polyaramid laminates: the 2024 study was read as an abstract only. No tensile, modulus or failure strain values were printed in the text used.'
  - 'Polyaramid/vinylester laminates: the 2010 Kevlar and vinyl ester study was read at the setup level (unidirectional Kevlar, 20, 40 and 60 wt percent, surface density 340 g/cm2). Its results were not in the text fetched. The MDPI MWCNT-anchored p-aramid paper was found but not read.'
  - 'Polyaramid/PPS hybrid laminates: no source was found for this pairing. Search returned PPS-carbon and PPS-glass data only, which are not used.'
  - Aramid laminate values (carbon/aramid, polyaramid/vinylester) are not in this file. The aramid numbers are for the Kevlar 49 yarn, not for a laminate.
  - 'UHMWPE mesh ageing: the paper gives UV and hygrothermal effects in words only. The retention table was not found in the full text read via Europe PMC, so no percent retention is given.'
  - No atomic oxygen, outgassing or total mass loss values were read for these systems.
  - Water uptake at saturation for the UHMWPE SRC and for aramid laminates was not read. The 3.5 percent value is the equilibrium of Kevlar 49 yarn from bone-dry yarn, under the conditions printed in the table.
  - Fibre volume fraction and void content of the SRC samples were not read as numbers.
  - 'Crystallinity, shear strength and decomposition temperature are not canonical benchmark names, so they are kept as snake_case names: crystallinity, shear_strength, decomposition_temperature.'
  - Foster 2016 gives Young modulus in GPa only in a figure, so only the text values are used.
  - Supply shares by country, abundance and critical-mineral status for the polyolefin and aramid fibres were not read. No critical-mineral list was checked.
  - Styrene hazards apply to the monomer, not a cured vinyl ester laminate. The resin SDS was not read.
  - Recycling data for SRC (for example, how many cycles keep the properties) was not found in a readable source.
sources:
  srpc-2021:
    title: On the Structural Peculiarities of Self-Reinforced Composite Materials Based on UHMWPE Fibers
    id: Zherebtsov D, Chukov D, et al., Polymers 13(9), 1408, doi 10.3390/polym13091408 (2021)
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC8123710
    year: 2021
    kind: paper
    license: open access (MDPI, CC BY)
  srpc-2020:
    title: Hybrid Self-Reinforced Composite Materials Based on Ultra-High Molecular Weight Polyethylene
    id: Zherebtsov D, Chukov D, et al., Materials 13(7), 1739, doi 10.3390/ma13071739 (2020)
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC7178665
    year: 2020
    kind: paper
    license: open access (MDPI, CC BY)
  foster-2016:
    title: The effect of draw ratio on the mechanical properties and crystalline structure of single polymer polypropylene composites
    id: Foster RJ, Hine PJ, Ward IM, Polymer 91, 156-161, doi 10.1016/j.polymer.2016.03.042 (2016); accepted manuscript read here
    url: https://eprints.whiterose.ac.uk/95612/7/DRpaper_resubmission.pdf
    year: 2016
    kind: paper
    license: accepted manuscript, White Rose Research Online
  tivar-1000:
    title: 'TIVAR 1000 UHMW-PE: Mitsubishi Chemical Advanced Materials (formerly Quadrant) material data sheet, Polymershapes copy'
    id: Mitsubishi Chemical Advanced Materials, ASTM-format data sheet
    url: https://www.polymershapes.com/wp-content/uploads/2020/09/Material_Data_TIVAR_1000_UHMW-PE.pdf
    year: 2020
    kind: datasheet
    license: manufacturer datasheet, cited not reproduced
  dupont-kevlar-guide:
    title: Technical Guide for Kevlar Aramid Fiber (DuPont), copy hosted by a third party
    id: DuPont Kevlar aramid fiber technical guide
    url: https://www.r-g.de/wiki/images/e/ec/Td_en_Kevlar_guide.pdf
    year: 2010
    kind: datasheet
    license: copy hosted by a third party, cited not reproduced
  kevlar-sds:
    title: KEVLAR Para-aramid Safety Data Sheet, Version 8.1 (Ref. 150000002634; revision 03/23/2023)
    id: DuPont SDS, copy hosted by Easy Composites
    url: https://media.easycomposites.co.uk/datasheets/Dupont-Kevlar-SDS-Ver8_1-23Mar2023.pdf
    year: 2024
    kind: datasheet
    license: supplier safety data sheet, cited not reproduced
  nasa-tp3473:
    title: 'NASA Technical Paper 3473: Performance Study of Galactic Cosmic Ray Shield Materials'
    id: Kim, Wilson, Thibeault, Nealy, Badavi, Kiefer, NASA TP 3473 (1994)
    url: https://ntrs.nasa.gov/api/citations/19950010497/downloads/19950010497.pdf
    year: 1994
    kind: report
    license: NASA public document
  mdpi-barrier:
    title: Study on the Aging Behavior of an Ultra-High Molecular Weight Polyethylene Fiber Barrier Net in a Marine Environment
    id: Materials 15(16), 5599, doi 10.3390/ma15165599 (2022)
    url: https://doi.org/10.3390/ma15165599
    year: 2022
    kind: paper
    license: open access (MDPI, CC BY)
  manipal-carbon-aramid:
    title: Experimental analysis of the effect of the woven aramid fabric on the in-plane tensile behaviour of carbon/epoxy laminates
    id: Zachariah SA, Shenoy S, et al., Facta Universitatis, Series Mechanical Engineering (2024), Manipal open access archive
    url: https://impressions.manipal.edu/open-access-archive/11369
    year: 2024
    kind: paper
    license: open access (Manipal institutional archive)
  pubchem-styrene:
    title: 'PubChem: Styrene (CID 7501), GHS classification summary'
    id: PubChem, National Center for Biotechnology Information
    url: https://pubchem.ncbi.nlm.nih.gov/compound/7501
    year: 2026
    kind: database
    license: PubChem public data
  tivar-vmx-sds:
    title: TIVAR VMX food-grade UHMW-PE safety data sheet (Boedeker copy, rev. Feb 2024)
    id: Mitsubishi Chemical Advanced Materials, SDS 1609-211004
    url: https://www.boedeker.com/Portals/0/Safety%20Data%20Sheets%20SDS/MCAM/MCAM-TIVAR-VMX-FOOD-GRADE-UHMW-EN-SDS-1609-211004-feb-2024.pdf
    year: 2024
    kind: datasheet
    license: safety data sheet, cited not reproduced
license: CC-BY-4.0
updated: '2026-10-26'
review:
  status: draft
  method: assistant
  checked_values: 29
  unreachable: 3
  caveats: 6
  note: 'First write on 2026-10-26: 29 values read in this run from fetched papers, datasheets and the DuPont Kevlar guide. Not reached: Curv and Pure PP datasheets (blocked), commercial PE/PE datasheets, aramid laminate numbers. Caveats: the UHMWPE SRC values are lab-made samples of SGX fibre; TIVAR values are an unfilled matrix grade, not the SRC matrix; the Kevlar values are for yarn, not laminates; the 190 C PP value is read from text, not the figure; styrene hazards are for the monomer; the 0.01 percent water absorption is an upper limit.'
documents:
  - title: On the Structural Peculiarities of Self-Reinforced Composite Materials Based on UHMWPE Fibers (Polymers 2021)
    type: paper
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC8123710
    year: 2021
  - title: Hybrid Self-Reinforced Composite Materials Based on UHMWPE (Materials 2020)
    type: paper
    url: https://pmc.ncbi.nlm.nih.gov/articles/PMC7178665
    year: 2020
  - title: The effect of draw ratio on the mechanical properties and crystalline structure of single polymer polypropylene composites (Polymer 2016)
    type: paper
    url: https://eprints.whiterose.ac.uk/95612/7/DRpaper_resubmission.pdf
    year: 2016
  - title: TIVAR 1000 UHMW-PE material data sheet (Mitsubishi Chemical Advanced Materials)
    type: datasheet
    url: https://www.polymershapes.com/wp-content/uploads/2020/09/Material_Data_TIVAR_1000_UHMW-PE.pdf
    year: 2020
  - title: Technical Guide for Kevlar Aramid Fiber (DuPont)
    type: datasheet
    url: https://www.r-g.de/wiki/images/e/ec/Td_en_Kevlar_guide.pdf
    year: 2010
  - title: KEVLAR Para-aramid Safety Data Sheet, Version 8.1
    type: sds
    url: https://media.easycomposites.co.uk/datasheets/Dupont-Kevlar-SDS-Ver8_1-23Mar2023.pdf
    year: 2024
  - title: 'NASA TP 3473: Performance Study of Galactic Cosmic Ray Shield Materials'
    type: report
    url: https://ntrs.nasa.gov/api/citations/19950010497/downloads/19950010497.pdf
    year: 1994
  - title: Study on the Aging Behavior of a UHMWPE Fiber Barrier Net in a Marine Environment (Materials 2022)
    type: paper
    url: https://doi.org/10.3390/ma15165599
    year: 2022
  - title: Experimental analysis of the effect of woven aramid fabric on carbon/epoxy laminates (2024)
    type: paper
    url: https://impressions.manipal.edu/open-access-archive/11369
    year: 2024
  - title: 'PubChem: Styrene (CID 7501), GHS classification summary'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/7501
    year: 2026
  - title: TIVAR VMX food-grade UHMW-PE safety data sheet (Boedeker copy)
    type: sds
    url: https://www.boedeker.com/Portals/0/Safety%20Data%20Sheets%20SDS/MCAM/MCAM-TIVAR-VMX-FOOD-GRADE-UHMW-EN-SDS-1609-211004-feb-2024.pdf
    year: 2024
story:
  recipe:
    line: 'Self-reinforced composites are made by hot compaction of oriented fibres or tapes of one polymer. The surface of each fibre melts and, on cooling, forms an isotropic matrix around the unmelted core, which keeps its orientation and carries the load. The UHMWPE SRC in the sources was pressed from SGX fibre (220 dtex) at 155 to 170 C and 25 to 50 MPa, with the heating time 50 minutes and the moulding time 10 minutes. Aramid composites are different: the fibre is a reinforcement in a separate resin matrix, and the sources read here give no laminate recipe.'
    parts:
      - name: UHMWPE fibre (Dyneema SGX, 220 dtex)
        share: Reinforcement; the paper gives no mass share, but the preserved fibre fraction is 88 percent at 155 C and 34 percent at 170 C
        role: Carries the load along the fibre direction; the preserved fibre fraction sets the strength.
      - name: Isotropic UHMWPE matrix (remelted fibre surface)
        share: Crystallinity 92 percent at 155 C and 69 percent at 170 C, against 291 J/g for 100 percent crystalline UHMWPE
        role: Bonds the fibres together and transfers load between them; the amount grows with compaction temperature.
  compare_rows:
    - scope: material
      label: Strength along the fibres
      benchmark: ultimate_tensile_strength
    - scope: material
      label: Stiffness
      benchmark: elastic_modulus
    - scope: material
      label: Density
      benchmark: density
  handling:
    - Avoid dust formation when cutting, sanding or machining aramid or polyolefin composites. Use ventilation or vacuum cleaning.
    - Wear safety glasses with side shields when working with aramid fibre dust.
    - Keep aramid yarn away from fluorescent lamps and window glass, since UV discolours it and can reduce its strength.
    - Check the SDS of the specific grade. TIVAR VMX is not GHS classified, while Kevlar is flagged for combustible dust.
  risk_groups:
    - title: For people
      lead: The sources read here show low acute hazard for the polyolefin and aramid fibres, with dust as the main concern.
      level: 1
      verdict: Dust is the main concern
      points:
        - label: Dust in the workshop
          line: Kevlar is classed for combustible dust, and the SDS advises avoiding dust formation. TIVAR VMX is not GHS classified but also advises avoiding dust.
        - label: Styrene in vinyl ester resins
          line: PubChem lists styrene as flammable and harmful if inhaled, a suspected reproductive hazard and a specific organ toxicant on repeated exposure. Check the resin SDS.
    - title: If it fails
      lead: The fibre direction decides the weak direction. The UHMWPE SRC is strong along the fibres and weak across them.
      points:
        - label: Loading across the fibres
          line: The SRC gives 7.7 MPa across the fibres against 174.3 MPa along them, so layup decides how much of the strength a part can use.
        - label: Heat during compaction
          line: At 170 C only 34 percent of the fibres survive compaction, so the process window is narrow.
        - label: UV on aramid
          line: Unprotected aramid yarn yellows and can lose strength under UV. Shielding from UV is the mitigation the guide gives.
    - title: Handling and storage
      points:
        - label: Keep it dry and shielded
          line: Aramid moisture equilibrium is 3.5 percent for Kevlar 49 yarn from bone-dry state, so the yarn picks up moisture in use.
  why: Self-reinforced composites give a light, recyclable laminate from one polymer family. The UHMWPE SRC reaches 174.3 MPa along the fibres with a density of about 1.0 g/cm3, and its matrix is an unfilled UHMW-PE that melts at 135 C. Para-aramid fibre gives the highest tensile values in this file, 3000 MPa and 112400 MPa for Kevlar 49 yarn, with a 1.44 g/cm3 density. Both systems are limited across the fibres and by heat or UV.
  compare: The UHMWPE SRC is about four times as strong along the fibres as the unfilled UHMW-PE sheet (174.3 MPa against 40.0 MPa), and its density of about 1.0 g/cm3 is well below the 1.44 g/cm3 of Kevlar 49 yarn. The Kevlar yarn is about 17 times stronger than the SRC along the fibres (3000 MPa against 174.3 MPa), but the figures are for a single fibre bundle against a lab-made composite, so they are not directly comparable.
  can_do:
    - where: Structures
      line: The SRC is made into flat plates by hot compaction, and the sources report 110.2 to 117.3 MPa in flexure at 155 to 170 C.
      label: Property
    - where: Radiation shielding
      line: Polyethylene (neat) is named in NASA work as an effective galactic cosmic ray shield, because of its high hydrogen content.
      label: Use
  good_for:
    - Light structural parts where strength is needed along one direction and recyclability matters.
    - Radiation shielding in polyethylene form, with the SRC as a route to a stiffer polyethylene part (not tested in the sources here).
  watch_out:
    - Compaction temperature sets the reinforcement left in the part. Near 170 C, most of the fibres melt.
    - Across-fibre strength is about 7.7 MPa for the SRC, far below the along-fibre value.
    - Aramid yarn needs UV shielding and dust control.
  verdict: Strong along the fibre and recyclable in principle, but weak across it and sensitive to compaction temperature; the aramid values are for the fibre, and laminate data for the aramid systems is still missing.
  uses:
    - where: Structural plates
      line: The UHMWPE SRC is pressed into flat plates in the lab, with the authors framing it as a lightweight alternative to carbon and glass composites.
    - where: Radiation shielding
      line: NASA TP 3473 tests polyethylene as a galactic cosmic ray shield and quotes Shinn et al. calling it effective because of its short nuclear absorption lengths.
    - where: Carbon-aramid hybrid laminates
      line: Woven aramid fibre is added to carbon-epoxy laminates as a high-strain layer, which the authors study for in-plane tensile behaviour and, in the cited literature, for impact strength.