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US20050064163A1 - Process for fabricating polypropylene sheet - Google Patents

Process for fabricating polypropylene sheet Download PDF

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US20050064163A1
US20050064163A1 US10496294 US49629404A US2005064163A1 US 20050064163 A1 US20050064163 A1 US 20050064163A1 US 10496294 US10496294 US 10496294 US 49629404 A US49629404 A US 49629404A US 2005064163 A1 US2005064163 A1 US 2005064163A1
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temperature
cooling
phase
process
preferably
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US10496294
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Ian Ward
Peter Hine
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PORPEX OPERATING Co LLC
Propex Operating Co LLC
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BTG International Ltd
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    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/006Pressing and sintering powders, granules or fibres
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL
    • B29CSHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
    • B29C43/00Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor
    • B29C43/003Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor characterised by the choice of material
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS
    • B29K2023/00Use of polyalkenes or derivatives thereof as moulding material
    • B29K2023/10Polymers of propylene
    • B29K2023/12PP, i.e. polypropylene
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS
    • B29K2105/00Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/06Condition, form or state of moulded material or of the material to be shaped containing reinforcements, fillers or inserts
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS
    • B29K2105/00Condition, form or state of moulded material or of the material to be shaped
    • B29K2105/25Solid
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS
    • B29K2223/00Use of polyalkenes or derivatives thereof as reinforcement
    • B29K2223/10Polymers of propylene
    • B29K2223/12PP, i.e. polypropylene
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS
    • B29K2995/00Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0037Other properties
    • B29K2995/0077Yield strength; Tensile strength
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS
    • B29K2995/00Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0037Other properties
    • B29K2995/0082Flexural strength; Flexion stiffness
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B29WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL
    • B29KINDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS
    • B29K2995/00Properties of moulding materials, reinforcements, fillers, preformed parts or moulds
    • B29K2995/0037Other properties
    • B29K2995/0083Creep
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/249921Web or sheet containing structurally defined element or component
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/249921Web or sheet containing structurally defined element or component
    • Y10T428/249924Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00Stock material or miscellaneous articles
    • Y10T428/249921Web or sheet containing structurally defined element or component
    • Y10T428/249924Noninterengaged fiber-containing paper-free web or sheet which is not of specified porosity
    • Y10T428/24994Fiber embedded in or on the surface of a polymeric matrix

Abstract

A process for production of a monolithic article from a web of fibres of oriented polypropylene homopolymer or copolymer having a weight average molecular weight (Mw) of at least 250,000 includes the steps of subjecting the web to elevated temperature and pressure sufficient to melt a proportion of the polymer and compact it, and thereby yielding an oriented phase and a matrix phase, and effecting a heat treatment selected from (i) subjecting the compacted web to a retarded rate of cooling down to a lower temperature at or below the temperature a which the recrystallisation of the matrix is complete; and (ii) annealing the compacted web at an annealing temperature within 15° C. of the temperature at which the matrix phase is completely melted. The resultant articles have good stiffness and strength, and acceptable ductility, yet corresponding articles made with polypropylene of lower Mw are brittle.

Description

  • [0001]
    The present invention relates to polymer sheet materials made from oriented olefin polymer fibres or tapes, and in particular an improved process for making such materials.
  • [0002]
    In recent years, developments have been made in processes for compacting polyolefin fibres in order to make sheets of high stiffness and strength. Two-step compaction processes for melt-spun fibres employing high compaction pressures are well known. An example is disclosed in GB 2253420A, in which an assembly of fibres of an oriented polymer is hot compacted in a two-step process to form a sheet having good mechanical properties. The process involves an initial step in which the fibres are brought to and held at the compaction temperature whilst subject to a pressure sufficient to maintain the fibres in contact, and thereafter compacted at a high pressure (40-50 MPa) for a few seconds (the compaction pressure). In this process a proportion of the fibre surfaces, generally from 5 to 10 percent by weight, melt and subsequently recrystallise on cooling. This recrystallised phase binds the fibres together, resulting in good mechanical properties of the final sheet.
  • [0003]
    It is mentioned in GB 2253420A that the process can be applied to many types of oriented polymer including polyester and PEEK (polyether ether ketone) but that preferred polymers are oriented polyolefins. Polyethylene is the only polyolefin mentioned, and is used in all of the examples.
  • [0004]
    In WO 98/15397, an improvement to the above process is disclosed in which an assembly of melt-formed polyolefin fibres is maintained in intimate contact at elevated temperature sufficient to melt a proportion of the fibres, whilst being subjected to a compaction pressure of no greater than 10 MPa. This single-step, low-pressure process also produces products having excellent mechanical properties. If wished the fibres may have been subjected to a prior crosslinking process, preferably an irradiation crosslinking process comprising irradiating the fibres with an ionising radiation in an inert environment containing alkyne or diene compounds, and then an annealing step comprising annealing the irradiated polymer at an elevated temperature, in an inert environment containing alkyne or diene compounds.
  • [0005]
    In GB 2253420A it is stated that “the hot compacted materials are preferably cooled to ambient temperature under controlled conditions. Rapid cooling is less preferred. The most convenient technique is to allow the compacts to stand in the air until they have cooled to ambient temperature.” The examples of GB 2253420A do not mention cooling rate.
  • [0006]
    In the examples of WO 98/15397 the compaction temperature and pressure were applied and the assembly was cooled under the compaction pressure to 100° C. by passing a mixture of air and water through the heating platens. At this point the assembly was removed from the press and cooled to room temperature in air with no pressure applied. Cooling rate is not mentioned.
  • [0007]
    In Plastics, Rubber and Composites Processing and Applications, 1998, Vol 27, No. 4, pgs 167-171, specifically in relation to polyethylene it was stated that “the final cooling rate does not significantly affect the structure or properties of the final compacted sheet: quenched samples have been measured to have almost identical properties to slow cooled samples.”
  • [0008]
    We have discovered that unlike polyethylene, in the case of polypropylene the cooling rate may have a significant effect on the final properties of the compacted sheet. We have discovered that post-compaction annealing may also have a significant effect. Such measures have been shown to result in improvement of certain properties, including stiffness and yield stress, with maintenance of acceptable ductility and related properties. Surprisingly, this promising array of properties has been found to be achieved in certain polypropylene materials only.
  • [0009]
    Accordingly in a first aspect, the present invention provides a process for production of a monolithic article from a web of fibres of oriented polypropylene homopolymer or copolymer having a weight average molecular weight (Mw) of at least 250,000, the process comprising the steps of subjecting the web to elevated temperature and pressure sufficient to melt a proportion of the polymer and compact it, thereby yielding an oriented phase and a matrix phase, and effecting a heat treatment selected from
      • (i) subjecting the compacted web to a retarded rate of cooling down to a lower temperature at or below the temperature at which the recrystallisation of the matrix is complete; and
      • (ii) annealing the compacted web at an elevated annealing temperature.
  • [0012]
    The fibres can be made by any suitable process, for example solution or gel or melt forming, preferably by melt forming.
  • [0013]
    The term “fibres of oriented polypropylene homopolymer or copolymer” is used herein to mean all elongate elements which comprise polypropylene. They may be in the form of strands or filaments. They may be in the form of bands, ribbons or tapes, formed for example by initially slitting melt formed films. Whatever their form the fibres may be laid in a non-woven web for the process of the invention. Alternatively they may be formed into yarns comprising multiple fibres, or used in the form of a monofilament yarn. The fibres are usually formed into a fabric by weaving or knitting. Optionally the fibres may have been subjected to a crosslinking process, as described in WO 98/15397. Woven fabrics may comprise only fibres in the form of strands or filaments, or they may comprise a mixture of fibres in the form of strands or filaments and fibres in the form of tapes. Most preferred are fabrics which are woven from flat tapes, as these have the best mechanical properties.
  • [0014]
    “A retarded rate of cooling” in this specification means cooling under conditions such that heat is lost from the compacted web more slowly than if it were cooled from the elevated temperature to said lower temperature under ambient conditions, that is, in still air at ambient temperature, typically 20° C.
  • [0015]
    The following paragraphs further define or describe the heat treatment variant (i), of subjecting the compacted web to a retarded rate of cooling down to a lower temperature at or below the temperature at which the recrystallisation of the matrix is complete.
  • [0016]
    The retarded cooling step (i) preferably takes place immediately after compaction. More preferably, it takes place immediately after compaction without the compacted web having been removed from the compaction apparatus.
  • [0017]
    In this heat treatment variant (i) the mean cooling rate from the compaction temperature down to said lower temperature is suitably not greater than 10° C./min, preferably not greater than 5° C./min, more preferably not greater than 3° C./min and, especially, not greater than 2° C./min. Whilst the preceding definitions are of mean cooling rate, preferably the cooling rate is retarded for the entire cooling regime, down to said lower temperature.
  • [0018]
    Preferably said lower temperature is below the temperature at which the recrystallisation of the matrix is complete. Suitably it is up to 5° C. lower. Preferably it is up to 10° C. lower.
  • [0019]
    Preferably said lower temperature is in the range 100-110° C. Most preferably the lower temperature is 100° C.
  • [0020]
    The following paragraphs further describe or define the heat treatment step (ii), of annealing the compacted web at an elevated annealing temperature.
  • [0021]
    Preferably annealing takes place within 15° C. of the temperature at which the matrix phase is completely melted, more preferably within 10° C. of this temperature, still more preferably within 5° C. of this temperature, and most preferably within 3° C. of this temperature.
  • [0022]
    In principle it could be possible to anneal the compacted web at a temperature at or above the temperature at which the matrix phase is completely melted, because of the stabilisation provided by the oriented phase, which melts at a higher temperature. Preferably, however, the annealing temperature is below the temperature at which the matrix phase is completely melted.
  • [0023]
    Most preferred, therefore, is an annealing temperature which is within 3° C. of the temperature at which the matrix phase is completely melted, but below that temperature. Such an annealing temperature has been found to give excellent results.
  • [0024]
    Preferably a heat treatment step (ii) is effected for at least 1 minute, preferably for at least 2 minutes, more preferably for at least 3 minutes, and most preferably for at least 5 minutes.
  • [0025]
    A heat treatment step (ii) may be effected immediately after compaction. Alternatively it is possible to temporally space the compaction step and a heat treatment step (ii), in accordance with the present invention. That is, a process in which compaction takes place and the compacted web is cooled by a regime not necessary in accordance with heat treatment step (i), but which is later heated for such a heat treatment step (ii) then to be carried out, is not excluded.
  • [0026]
    One embodiment of the present invention employs only a retarded cooling step (i). The retarded cooling is suitably carried out immediately after compaction, without the compacted web having been cooled first. Thus, the temperature of the compacted web is allowed to fall from the compaction temperature to the lower temperature.
  • [0027]
    One embodiment of the present invention employs only an annealing step (ii).
  • [0028]
    In one embodiment of the present invention both a retarded cooling step (i) and an annealing step (ii) are employed. For example an annealing step (ii) may be followed directly by a retarded cooling step (i), with the starting point of the retarded cooling step being the annealing temperature rather than a compaction temperature, and with the annealing temperature and said lower temperature providing the temperature end points across which the mean cooling rate may be determined. In another example compaction is followed by a retarded cooling step (i), followed by later reheating to effect an annealing step (ii).
  • [0029]
    It is preferred that the hot compaction process of the invention uses a compaction pressure not exceeding 10 MPa. It is also preferred that a single pressure is used throughout the hot compaction process. Most preferred pressures are between 1 and 7 MPa, particularly between 2 and 5 MPa. It is preferred that the hot compaction pressure is maintained during cooling.
  • [0030]
    The minimum temperature at which the fibres should be contacted is preferably that at which the leading edge of the endotherm, measured by Differential Scanning Calorimetry (DSC), of the constrained polymer fibres extrapolated to zero intersects the temperature axis. Preferably, the temperature at which the fibres are compacted is no greater than the constrained peak temperature of melting at the ambient compaction pressure—i.e. the temperature at which the endotherm reaches it highest point. The proportion of the fibres which is melted during the hot compaction process is generally between 10 and 50 percent by weight.
  • [0031]
    Preferably the fibres used in the present invention have a weight average molecular weight (Mw) in the range 250,000 to 450,000, most preferably 330,000 to 400,000, as determined by the method hereinafter described. The polymer is preferably a polypropylene homopolymer, but may be a copolymer comprising polypropylene. Generally any copolymer containing polypropylene such as those disclosed in WO 98/15397 may be used.
  • [0032]
    Preferably the fibres have not been subjected to a prior crosslinking process, for example of the type described in WO 98/15397.
  • [0033]
    Compaction of the polypropylene may be carried out in an autoclave, or in a belt press or other apparatus in which the assembly is fed through a compaction zone where it is subjected to the required elevated temperature and pressure. Thus, the process may be operated as a continuous or semi-continuous process. Cooling is preferably effected whilst the compacted web is restrained against dimensional change, for example by being held under tension, which may be applied uniaxially or biaxially, or by being still under a compaction pressure. The restraint may assist the maintenance of good properties in the oriented phase.
  • [0034]
    The monolithic article may be regarded as a polypropylene composite made up of a polypropylene matrix phase which was produced during the process, and a polypropylene fibre phase, a proportion of which may show selective surface melting, arising from the process. The properties of each are of significance in achieving a monolithic article of the required properties, and they may be defined, and studied, separately.
  • [0035]
    Preferably the Young's modulus of the matrix phase is at least 0.9 GPa, more preferably at least 1.2 GPa, more preferably 1.5 GPa, and most preferably at least 1.7 GPa.
  • [0036]
    Preferably the failure strength of the matrix phase is at least 20 MPa, more preferably at least 25 MPa.
  • [0037]
    Preferably the failure strain of the matrix phase is at least 5%.
  • [0038]
    Preferably the Young's modulus in the longitudinal direction (which may alternatively be called the draw or axial direction) of the fibre phase is at least 4 GPa, more preferably at least 6 GPa.
  • [0039]
    Preferably the failure strength in the longitudinal direction of the fibre phase is at least 250 MPa, more preferably at least 350 MPa, and most preferably at least 400 MPa.
  • [0040]
    Preferably the failure strain in the longitudinal direction of the fibre phase is at least 5%, more preferably at least 8%, and most preferably at least 12%.
  • EXAMPLE SET A
  • [0041]
    The effect of cooling rate was established by examining the cooling of a completely melted fabric, to simulate the melted matrix phase in a hot compacted sheet. It has been found that the properties of a hot compacted sheet are a combination of the properties of the original oriented fibres (the reinforcing phase), and the portion of the fibres which are melted (the matrix phase). Therefore by examining the properties of a melted fabric which has been cooled at different rates, it is possible to simulate the effect of cooling a hot compaction sheet at different rates.
  • [0042]
    The fabrics used were made from a number of different melt-formed polypropylene homopolymers detailed in Table 1 below. The reinforcement type indicates the type of fibre from which the fabric is woven.
    TABLE 1
    Polymer No.
    1 2 3 4
    Reinforcement Multifilament Fibrillated Flat tape Flat tape
    type bundles tape
    Young's 9.5 10.9 6.2 6.8
    modulus
    E(GPa)
    Failure 453 350 370 422
    strength
    σF (MPa)
    Failure strain 12 6 16 16
    εF(%)
    Density 907 912 932 910
    ρ (kg/m3)
    Mn 38,500 55,800 56,100 78,100
    Mw 191,000 290,000 325,000 360,000
  • [0043]
    Mw and Mn were measured by Rapra Technology Limited, of Shropshire, UK. Details of the testing are as follows:
    • Instrument Waters 150CV
    • Columns Plgel 2×mixed bed-B, 30cn 10 microns
    • Solvent 1,2-dichlorobenzene with anti-oxidant
    • Flow-rate 1.0 ml/min (nominal)
    • Temperature 140° C. (nominal)
    • Detector refractive index and differential pressure
    • GPC system calibrated with polystyrene
  • [0051]
    Woven cloths made of each of the above polymers were completely melted by heating two layers of cloth in a hot press at 200° C. The pressure applied was 2.8 MPa, although since the samples were completely melted this was not critical. Cooling was achieved either by removing the sample and plunging it into water (quenching) or in the hot press by passing a coolant through the heated platens, after switching off the heating. Depending on the rate of cooling required 100% water, or air containing water droplets, was used as the coolant. In this example fast cooling in the press means a cooling rate of 20-30° C./min. The slow cooling rate, 1-2° C./min, was achieved by just switching off the heating and allowing the assembly to cool naturally in air.
  • [heading-0052]
    Mechanical Properties
  • [0053]
    The stress/strain behaviour of the above cooled films was measured using an RDP Howden servo-mechanical tensile testing machine. The tensile tests on the compacted sheets and the melted films were carried out following ASTM D638 using a dumbbell shaped specimen. A normal strain rate of 10−3 s−1 was used for all the tests. The sample strain during the tests was measured using a Messphysik video extensometer. Five samples were tested for each material at a temperature of 20±2° C. and a relative humidity of 35±5%.
  • [0054]
    Typical stress-strain curves are shown in FIG. 1, for each of the four polymer tests. The results show that for all four polymers, the quenched samples were ductile and drew in a stable manner with the formation of a stable neck region. Strain for these samples was measured from the crosshead speed, rather than directly on the sample, for if the neck formed outside the measured region, the strain in the measurement region actually decreased. However their Young's modulus and yield stress values were relatively low. The fast cooled and the quenched traces have been displaced a small way along the x-axis simply in order to display each trace clearly.
  • [0055]
    For the sample made using the fast cooling regime on-press, differences in behaviour were seen. The lowest molecular weight polymer (Polymer 1, Graph 1) showed an initial linear region, with an increased slope compared to the quenched sample, a yield point, again higher than the quenched sample, then rupture. This form of stress-strain behaviour is often termed necking-rupture. Two intermediate molecular weight samples (Polymers 2 and 3, Graphs 2 and 3) showed the formation of a neck but drawing did not stabilise and rupture occurred at ˜25% (0.25) strain. Only the highest molecular weight Polymer 4 (Graph 4) showed stable drawing following application of this cooling rate.
  • [0056]
    All the samples made by slow cooling showed necking-rupture or brittle behaviour. The failure strains of the original fibres were mostly between 10 and 20% (0.1 and 0.2): therefore if the matrix fails below this value then a hot compacted composite would see premature matrix failure before the reinforcing phase can reach full load carrying capacity, leading to premature delamination. It is seen that at the slowest cooling rate, none of the polymers reached this desired failure strain. In particular, the low molecular weight Polymer 1 showed brittle failure at a low stress. It may be seen that ductile-type behaviour became more pronounced as Mw increases; the highest failure strain was shown by Polymer 4. In most cases the initial slope of the slow-cooled samples was higher than either of the other two cooling rates, indicating that slow cooling gave highest Young's modulus. The failure stress for slow-cooled samples of Polymers 1 and 2 was less than for the fast cooled samples, but the failure stress for slow-cooled samples of Polymers 3 and 4 was approximately equal to the fast cooled samples.
  • [heading-0057]
    Density
  • [0058]
    The densities of the original oriented materials and the compacted sheets were measured using a density column. The column was made from a mixture of digycidyl ether and isopropanol to give a density range of ˜890 to ˜930 kg/m3. The results are shown in Table 2.
    TABLE 2
    Polymer Material and cooling regime Density (kg/m3)
    1 Original fibres 907
    Melted film - quenching 911
    Melted film - slow cooling 915
    2 Original fibres - (cloth D) 912
    Melted film - quenching 920
    Melted film - slow cooling 924
    3 Original tapes (cloth E) 910
    Melted film - quenching 920
    Melted film - slow cooling 925

    Modulus
  • [0060]
    The Young's Modulus was determined in the initial linear region of the stress strain curve following the guidelines of ASTM D638. The results are shown in Table 3 below.
    TABLE 3
    Young's modulus E (GPa)
    Fast Slow
    Polymer Quenching cooling cooling
    1 1.04 ± 0.02 1.85 ± 0.05 2.08 ± 0.13
    2 1.00 ± 0.03 1.58 ± 0.06 1.71 ± 0.11
    3 1.00 ± 0.09 1.24 ± 0.09 1.33 ± 0.01
    4 0.95 ± 0.06 1.22 ± 0.10 1.37 ± 0.08
  • [0061]
    Tables 2 and 3 show the density and Young's modulus of the various melted films. Both of these properties can be used as a measure of the crystallinity of the films, as one can attribute increases in either parameter with an increase in crystallinity. As the cooling rate is increased, the density of Young's modulus for each polymer type decreases, suggesting the expected decrease in crystallinity (and associated improvement in ductility).
  • [0062]
    It is clear from the results in Example Set A that the cooling rate of the hot compaction process is a key process parameter, because it has a significant effect on the mechanical properties of the matrix phase, probably due to changes in crystallinity. The above results show that slow cooling may lead to good Young's modulus and failure strain properties, but compromised ductility; but that for polymers of higher Mw a useful level of ductility may be achieved, especially for uses in which stiffness and failure strain are of primary importance. In general, slow cooled samples appear to show higher stiffness values than fast cooled samples, but may be brittle if the polypropylene is of low molecular weight. However, samples may show reasonable ductility if the polypropylene is of higher molecular weight.
  • EXAMPLE SET B
  • [0063]
    In these examples partially melted monolithic articles were prepared. Polymer 4 of Example Set A was used, with 4 layers of woven cloth in the compaction assembly. Compaction conditions of 5 minutes at 193° C. and a compaction pressure of 4.8 GPa were employed. Slow cooling (20-30° C./min) or fast cooling (1-2° C./min) was effected as described in Example Set A.
  • [0064]
    FIG. 2 shows the temperature/time plots for the two samples. It will be seen that the fast cooled sample undergoes very rapid cooling to 150° C. The slow cooled sample takes about 25 minutes to drop from 193° C. to 150° C., and about 80 minutes to drop from 193° C. to 100° C.
  • [heading-0065]
    Melting Points
  • [0066]
    The melting behaviour of the hot compacted sheets made using the two cooling rates were measured using Differential Scanning Calorimetry. Peak melting points of the matrix phase and oriented phase were thereby determined. Results are given in Table 4 below
    TABLE 4
    Peak melting point of Peak melting point of
    matrix phase oriented phase
    Cooling (° C.) (° C.)
    Fast cooled 162 177
    Slow cooled 168 179
  • [0067]
    It will be seen that with the slower cooled product the peak melting point of the matrix is substantially increased whilst that of the oriented phase is increased only a little. Given that the aim is to improve the microstructure of the matrix phase, preferably to be more highly crystalline and to have a larger average crystal size whilst not substantially affecting the oriented phase, this is a promising result.
  • [heading-0068]
    Stress-Strain Testing
  • [0069]
    Table 5 below shows average results from mechanical testing of the two samples.
    TABLE 5
    Modulus Strength
    Cooling (GPa) (MPa) Failure strain
    Fast cooled 3.0 ± 0.1 130 ± 10 13 ± 2
    Slow cooled 3.3 ± 0.1 141 ± 6  11 ± 1
  • [0070]
    It will be seen that the mechanical properties of the slow cooled sample were good, in showing improved modulus and strength without significant loss of ductility.
  • [heading-0071]
    Peel Strength
  • [0072]
    Experiments were also made to assess the peel strength of the slow and fast cooled samples, and the averaged results are shown in Table 6 below.
    TABLE 6
    Peel strength
    Compaction Cooling N/10 mm
    4.2 MPa/193° C. Fast cooled 7.5 ± 3.5
    Slow cooled 7.7 ± 1.9
  • [0073]
    The measured peel strengths were all quite high, with the slow cooled value holding up well in comparison to the fast cooled value.
  • EXAMPLE SET C
  • [heading-0074]
    Peel Strength
  • [0075]
    Next, samples of a hot compacted composite material from Polymer 1 were made as described in Example Set B above, ie only partially melted, and subjected to peel strength testing. The averaged results are shown in Table 7 below.
    TABLE 7
    Peel strength
    Compaction Cooling N/10 mm
    4.2 MPa/193° C. Fast cooled 3.0 ± 1.6
    Slow cooled 1.8 ± 0.6
  • [0076]
    Both values are low but slow cooling is shown to be disadvantageous, a finding not applicable to Polymer 4, having a much higher molecular weight.
  • [heading-0077]
    EXAMPLE SET D
  • [0078]
    Our results indicate that slow cooling can lead to high stiffness and high yield stress. However with polypropylene of low Mw the trade off of loss in ductility is severe; such materials are brittle after compaction and have a low failure strain. However with polypropylene of higher Mw ductility, and associated properties such as peel strength, may be acceptable. Thus, use of a higher Mw polypropylene with slow cooling after compaction offers the prospect of an article with an attractive blend of properties.
  • [0079]
    On the basis that a similar blend of properties might be achievable by holding the compacted article at an elevated temperature for a dwell time, annealing experiments were carried out.
  • [0080]
    The first annealing experiments were carried out on the fully melted Polymer 4, to make an article with, in effect, 100% matrix material, as this is the phase that is most likely to be affected, and any effects should be easy to interpret. The annealing regimes studied were 150° C. for five minutes and 160° C. for 5 minutes.
  • [0081]
    Differential scanning calorimetry (DSC) yielded the results in Table 8 below, indicating that annealing can substantially affect the crystallinity (indicated by the enthalpy) and the crystal size (indicated by the peak melting point), and that the higher temperature has a more pronounced effect.
    TABLE 8
    Enthalpy Peak melting point
    J/g/% ° C.
    As made 63.4/31 164
    150° C./5 minutes 70.1/34 163
    160° C./5 minutes 85.3/41 169
  • [0082]
    The articles were subjected to tensile testing at 20° C. and at a range of elevated temperatures and the results are presented in FIGS. 3 and 4.
  • [0083]
    From the traces in FIG. 3 it was determined that the modulus of each article was as follows:
    • Fast cooled (no annealing) 1.37 GPa
    • Slow cooled (no annealing) 1.85 GPa
    • Annealed, 160° C./5 mins 1.9 GPa
    • Annealed, 150° C./5 mins 2.2 GPa
  • [0088]
    The change in crystalline morphology is reflected in an increase in modulus, and also in yield stress, although the material annealed at 160° C. still remained pseudo-ductile. Finally the DTMA temperature scan shown in FIG. 4 (scan from 20 to 160° C. in 5° C. increments, tested at frequency of 1 Hz using a dynamic strain of 0.05%) shows the 160° C. annealed sample to have significantly better higher temperature performance. In FIG. 3 comparisons are shown with the slow cooled and fast cooled samples of Example Set A. In FIG. 4 a comparison is shown with an “original” article, this being one cooled at 20-30° C./min after compaction.
  • EXAMPLE SET E
  • [0089]
    In these tests, woven layers of Polymer 4 were used for the manufacture of partially melted hot compacted articles having an oriented fibre phase and a matrix phase. The conditions were 193° C. for 5 minutes, at a compaction pressure of 4.2 MPa. Annealing was as described in Example Set D.
  • [0090]
    DTMA temperature scan testing as described in Example Set D was carried out. The results are shown in FIG. 5. The trace marked “original” refers to a sample cooled at 20-30° C./min after compaction.
  • [0091]
    The relevance of the FIG. 5 results is that stiffness as a function of the temperature at which the tests were carried out is an indication of expected creep or high temperature performance. It is likely to depend on the matrix phase, between the oriented phase. It will be seen that there is an improvement in the performance in the annealed sample at temperatures above 40° C., relative to the fast cooled sample.
  • OVERALL CONCLUSIONS
  • [0092]
    Use of slow cooling and/or annealing, applied to compacted articles made in accordance with the present invention, comprising polypropylene of Mw at least 250,000, offers advantages in terms of high stiffness, high yield strength, high failure strength, good maintenance of stiffness at elevated temperatures and surprisingly good ductile-type properties such as peel strength and failure strain. The good balance of properties is surprising having regard to the brittleness and/or low yield strength of corresponding articles made using polypropylene of Mw less than 250,000.

Claims (23)

  1. 1. A process for production of a monolithic article from a web of fibres of oriented polypropylene homopolymer or copolymer having a weight average molecular weight (Mw) of at least 250,000, the process comprising the steps of subjecting the web to elevated temperature and pressure sufficient to melt a proportion of the polymer and compact it, thereby yielding an oriented phase and a matrix phase, and effecting a heat treatment selected from
    (i) subjecting the compacted web to a retarded rate of cooling down to a lower temperature at or below the temperature at which the recrystallisation of the matrix is complete; and
    (ii) annealing the compacted web at an elevated annealing temperature.
  2. 2. A process as claimed in claim 1 wherein for the heat treatment step (i) the mean cooling rate from the compaction temperature down to said lower temperature is not greater than 5° C./minute.
  3. 3. A process as claimed in claim 2 wherein for the heat treatment step (ii) the mean cooling rate from the compaction temperature down to said lower temperature is not greater than 3° C./minute.
  4. 4. A process as claimed in claim 1 wherein for the heat treatment step (ii) the elevated annealing temperature is within 15° C. of the temperature at which the matrix phase is completely melted.
  5. 5. A process as claimed in claim 1 wherein for the heat treatment step (ii) the annealing temperature is below the temperature at which the matrix phase is completely melted, and up to 10° C. below that temperature.
  6. 6. A process as claimed in claim 5 wherein for the heat treatment step (ii) the annealing temperature is below the temperature at which the matrix phase is completely melted, and is up to 5° C. below that temperature.
  7. 7. A process as claimed in claim 1 wherein for the heat treatment step (ii) the compacted web is within the defined temperature range for at least 3 minutes.
  8. 8. A process as claimed in claim 7 wherein for the heat treatment step (ii) the compacted web is within the defined temperature range for at least 5 minutes.
  9. 9. A process as claimed in claim 1 wherein the heat treatment is carried out with the web restrained against dimensional change.
  10. 10. A process as claimed in claim 9 wherein the heat treatment is effected with the compacted web under tension.
  11. 11. A process as claimed in claim 9 wherein the heat treatment is effected with the compacted web retained in the compaction apparatus.
  12. 12. A process as claimed in claim 1 wherein the compaction pressure does not exceed 10 MPa.
  13. 13. A process as claimed in claim 1 wherein the weight average molecular weight (Mw) of the fibres is in the range 250,000 to 400,000.
  14. 14. A process as claimed in claim 13 wherein the weight average molecular weight (Mw) of the fibres is in the range 300,000 to 400,000.
  15. 15. A process as claimed in claim 1 wherein the fibres are melt formed fibres.
  16. 16. A monolithic article manufactured by a process as claimed in claim 1, having a matrix of polymer produced by selective melting of oriented fibres during the process, and oriented fibres remaining from that selective melting.
  17. 17. A monolithic article as claimed in claim 16 wherein the Young's modulus of the matrix phase is at least 0.9 GPa.
  18. 18. A monolithic article as claimed in claim 16 wherein the failure strength of the matrix phase is at least 20 MPa.
  19. 19. A monolithic article as claimed in claim 16 wherein the failure strain of the matrix phase is at least 5%.
  20. 20. A monolithic article as claimed in claim 16 wherein the Young's modulus in the longitudinal direction of the oriented fibre phase is at least 4 GPa.
  21. 21. A monolithic article as claimed in claim 16 wherein the failure strength in the longitudinal direction of the oriented fibre phase is at least 250 MPa.
  22. 22. A monolithic article as claimed in claim 16 wherein the failure strain in the longitudinal direction of the oriented fibre phase is at least 5%.
  23. 23. A process for fabricating a monolithic article of a polypropylene polymer, or a monolithic article thus formed, substantially as hereinbefore described with particular reference to the accompanying examples.
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100078439A1 (en) * 2006-12-06 2010-04-01 Franciscus Antonius Henri Janssen Use of a composite material as a barrier under cryogenic conditions

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CA2461349C (en) 2001-09-26 2011-11-29 Baxter International Inc. Preparation of submicron sized nanoparticles via dispersion and solvent or liquid phase removal
WO2003042788A3 (en) 2001-11-13 2004-02-19 Chromavision Med Sys Inc A system for tracking biological samples
GB0128405D0 (en) 2001-11-27 2002-01-16 Btg Int Ltd Process for fabricating polyolefin sheet
CN101844385A (en) 2003-05-22 2010-09-29 英国技术集团国际有限公司 Process for fabricating polymeric articles
JP2008517804A (en) 2004-10-22 2008-05-29 ダウ グローバル テクノロジーズ インコーポレイティド Improved polyolefin material for the plastic composite material
US7378359B2 (en) 2005-09-27 2008-05-27 Eleazer Howell B Moldable fibrous construction incorporating non-woven layers
US7294384B2 (en) 2005-09-27 2007-11-13 Milliken & Company Moldable construction incorporating bonding interface
US7300691B2 (en) 2005-09-27 2007-11-27 Milliken & Company Moldable construction incorporating non-olefin bonding interface
US20080124513A1 (en) 2006-09-11 2008-05-29 Eleazer Howell B Moldable fabric with unidirectional tape yarns
DE102008011303B4 (en) * 2008-02-27 2013-06-06 Siemens Aktiengesellschaft Operating method for a cooling section for cooling of a rolled material with the temperature of detached cooling to a Endenthalpiewert
JP5850686B2 (en) * 2011-09-26 2016-02-03 積水化学工業株式会社 The resin molded product manufacturing method and a resin molded product
WO2014182514A1 (en) 2013-05-06 2014-11-13 Milliken & Company Fiber reinforced structural element
DE102014203235A1 (en) 2014-02-24 2015-08-27 Mahle International Gmbh Air conditioner, particularly for a motor vehicle and method for producing a component of an air conditioner
WO2016198097A1 (en) 2015-06-09 2016-12-15 Müller Textil GmbH Composite tent tarpaulin and tent arrangement
JP6097367B2 (en) * 2015-10-02 2017-03-15 積水化学工業株式会社 The resin molded product manufacturing method and a resin molded product

Citations (54)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3231650A (en) * 1960-03-11 1966-01-25 Phillips Petroleum Co Non-woven polyolefin fabrics and method of preparing same
US3689597A (en) * 1970-06-26 1972-09-05 Hercules Inc Polyphase compositions and process for their preparation
US3884521A (en) * 1973-09-24 1975-05-20 Moore Alvin E Light-weight, durable, land-traversing vehicle
US3947537A (en) * 1971-07-16 1976-03-30 Exxon Research & Engineering Co. Battery separator manufacturing process
US3962205A (en) * 1973-03-06 1976-06-08 National Research Development Corporation Polymer materials
US3997386A (en) * 1974-05-31 1976-12-14 Mitsubishi Jukogyo Kabushiki Kaisha Method for bonding thermoplastic high molecular weight materials
US4013816A (en) * 1975-11-20 1977-03-22 Draper Products, Inc. Stretchable spun-bonded polyolefin web
US4048364A (en) * 1974-12-20 1977-09-13 Exxon Research And Engineering Company Post-drawn, melt-blown webs
US4082731A (en) * 1973-02-12 1978-04-04 Avtex Fibers Inc. Method for producing a high modulus polyester yarn
US4091140A (en) * 1976-05-10 1978-05-23 Johnson & Johnson Continuous filament nonwoven fabric and method of manufacturing the same
US4110391A (en) * 1976-07-31 1978-08-29 Ruhrchemie Aktiengesellschaft Process for the manufacture of molded articles from polyolefins with molecular weights of at least one million
US4191718A (en) * 1977-12-19 1980-03-04 Ford Motor Company Thick section compression molded composites
US4228118A (en) * 1977-11-03 1980-10-14 Monsanto Company Process for producing high tenacity polyethylene fibers
US4234536A (en) * 1978-09-27 1980-11-18 Thiel Alfons W Method for the manufacture of thin-walled shaped articles of crystalline thermoplastic material
US4285748A (en) * 1977-03-11 1981-08-25 Fiber Industries, Inc. Selfbonded nonwoven fabrics
US4287149A (en) * 1973-10-03 1981-09-01 National Research Development Corp. Process for the production of polymer materials
US4403012A (en) * 1982-03-19 1983-09-06 Allied Corporation Ballistic-resistant article
US4413110A (en) * 1981-04-30 1983-11-01 Allied Corporation High tenacity, high modulus polyethylene and polypropylene fibers and intermediates therefore
US4454270A (en) * 1981-12-14 1984-06-12 Ethyl Corporation Method and composition for preventing or suppressing discoloration in polyolefins
US4455273A (en) * 1982-09-30 1984-06-19 Allied Corporation Producing modified high performance polyolefin fiber
US4483727A (en) * 1983-02-07 1984-11-20 Celanese Corporation High modulus polyethylene fiber bundles as reinforcement for brittle matrices
US4525564A (en) * 1975-11-05 1985-06-25 National Research Development Corporation High modulus, low creep strain polyalkene polymer materials
US4551296A (en) * 1982-03-19 1985-11-05 Allied Corporation Producing high tenacity, high modulus crystalline article such as fiber or film
US4568581A (en) * 1984-09-12 1986-02-04 Collins & Aikman Corporation Molded three dimensional fibrous surfaced article and method of producing same
US4642153A (en) * 1983-05-31 1987-02-10 Allen Industries, Inc. Method and apparatus for making a sheet of material
US4654262A (en) * 1985-04-10 1987-03-31 Itt Corporation Polyolefin resin surface preparation
US4668577A (en) * 1983-09-09 1987-05-26 Toyo Boseki Kabushiki Kaisha Polyethylene filaments and their production
US4786348A (en) * 1987-01-05 1988-11-22 E. I. Du Pont De Nemours And Company Method of making transparent oriented sheets
US4792426A (en) * 1985-05-28 1988-12-20 Usm Corporation Precision control of the thickness of heat-softenable material
US4923660A (en) * 1985-05-08 1990-05-08 Bernd Willenberg Process for the production of mouldings and films from thermotropic polymers
US4931230A (en) * 1986-05-08 1990-06-05 Minnesota Mining And Manufacturing Company Method for preparing radiation resistant polypropylene articles
US4938913A (en) * 1984-04-13 1990-07-03 National Research Development Corporation Solid phase deformation process
US4948661A (en) * 1987-07-10 1990-08-14 C. H. Masland & Sons Glossy finish fiber reinforced molded product and processes of construction
US4990204A (en) * 1987-10-27 1991-02-05 The Dow Chemical Company Improved spunbonding of linear polyethylenes
US5006390A (en) * 1989-06-19 1991-04-09 Allied-Signal Rigid polyethylene reinforced composites having improved short beam shear strength
US5032339A (en) * 1990-07-19 1991-07-16 E. I. Du Pont De Nemours And Company Process for shaping fiber reinforced thermoplastic articles
US5135804A (en) * 1983-02-18 1992-08-04 Allied-Signal Inc. Network of polyethylene fibers
US5200131A (en) * 1990-04-09 1993-04-06 Mitsui Toatsu Chemicals, Inc. Method for molding syndiotactic polypropylene
US5244482A (en) * 1992-03-26 1993-09-14 The University Of Tennessee Research Corporation Post-treatment of nonwoven webs
US5324576A (en) * 1993-08-25 1994-06-28 Minnesota Mining And Manufacturing Company Polyolefin meltblown elastic webs
US5498129A (en) * 1994-05-04 1996-03-12 Eurocopter France Counter-torque device with ducted tail rotor and ducted flow-straightening stator, for helicopters
US5514448A (en) * 1992-07-22 1996-05-07 Mitsui Toatsu Chemicals, Inc. Laminated molding
US5628946A (en) * 1991-03-07 1997-05-13 British Technology Group Limited Process for producing polymeric materials
US5688426A (en) * 1995-06-07 1997-11-18 The Boeing Company Hybrid metal webbed composite beam
US5879607A (en) * 1994-05-11 1999-03-09 Raytheon Ti Systems & University Of Massachusetts Method of making a protective coating material
US6132657A (en) * 1998-06-29 2000-10-17 Polyeitan Composites Ltd. Process for producing polymeric materials
US6277773B1 (en) * 1991-03-07 2001-08-21 Btg International Limited Polymeric materials
US6312638B1 (en) * 1996-10-04 2001-11-06 Btg International Process of making a compacted polyolefin article
US6328923B1 (en) * 1996-10-04 2001-12-11 Btg International Limited Process of making a compacted polyolefin article
US6482343B1 (en) * 1999-06-28 2002-11-19 Polyeitan Composites Ltd. Polymeric materials and process for producing same
US20040169304A1 (en) * 2001-06-15 2004-09-02 Ward Ian M Amorphous polymer article
US20040185732A1 (en) * 2001-05-09 2004-09-23 Bonner Mark James Polyolefin sheet
US20040213977A1 (en) * 1996-01-15 2004-10-28 Btg International Limited Compacted biomaterials
US20050170730A1 (en) * 1996-01-15 2005-08-04 Btg International Limited Compacted biomaterials

Family Cites Families (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB397656A (en) * 1932-07-22 1933-08-31 Gen Electric Co Ltd Improvements in the manufacture of thermionic cathodes for electric discharge devices
US3017834A (en) * 1943-08-28 1962-01-23 Robert H Park Magnetic detecting device
US3367926A (en) * 1964-03-25 1968-02-06 Dow Chemical Co Modification of crystalline structure of crystallizable high polymers
JPS462192Y1 (en) 1967-11-06 1971-01-25
GB1469526A (en) * 1973-03-06 1977-04-06 Nat Res Dev Polymer materials
JPS5737609B2 (en) 1974-07-15 1982-08-11
JPS5419027B2 (en) 1974-09-26 1979-07-12
JPS541833B2 (en) 1975-09-19 1979-01-30
US4384016A (en) 1981-08-06 1983-05-17 Celanese Corporation Mutiaxially oriented high performance laminates comprised of uniaxially oriented sheets of thermotropic liquid crystal polymers
EP0116845B1 (en) 1983-02-18 1989-12-20 AlliedSignal Inc. Consolidation of polyethylene fibrous networks
GB8332952D0 (en) 1983-12-09 1984-01-18 Ward I M Polymer irradiation
US4551293A (en) * 1984-03-05 1985-11-05 Jamak, Inc. Method of forming spark plug boots
US4607640A (en) * 1985-11-18 1986-08-26 Mccusker Leroy H Athletic/industrial brassiere with protective inserts
WO1988009406A1 (en) * 1987-05-21 1988-12-01 Automotive Investment Co. Molding process using polypropylene strands and fabric fibers to produce article
CA1323301C (en) 1987-06-05 1993-10-19 Alan I. Faden Thyrotropin-releasing hormone analogs in cns injury
NL8801195A (en) 1988-05-06 1989-12-01 Stamicarbon Ballistic structure.
JPH07103507B2 (en) 1988-08-23 1995-11-08 ユニチカ株式会社 Nonwoven fabric made of heat-adhesive filaments
NL8900475A (en) 1989-02-25 1990-09-17 Stamicarbon A method for the manufacture of products containing polyolefin fibers.
CA2011182C (en) 1989-04-07 1993-12-07 Thomas I. Insley Sorbent, impact resistant container
NL8902194A (en) 1989-08-31 1991-03-18 Stamicarbon Tissue from thermoplastische- and continuous reinforcement fiber.
NL9002590A (en) 1990-11-28 1992-06-16 Stamicarbon Multi-layer anti-ballistic structure.
NL9200625A (en) 1992-04-03 1993-11-01 Dsm Nv Non-woven layer consisting of polyolefin for use in a layered ballistic-resistant structure.
JPH0687185A (en) * 1992-07-22 1994-03-29 Mitsui Toatsu Chem Inc Laminate moldings
US5654045A (en) 1992-12-21 1997-08-05 Hoechst Celanese Corp. Multiaxially reinforced LCP sheet
BE1007230A3 (en) 1993-06-23 1995-04-25 Dsm Nv COMPOSITE JOB mutually parallel fibers in a matrix.
JP2602166B2 (en) 1993-07-12 1997-04-23 内藤 治 Heat-resistant nonwovens and manufacturing method thereof
JP3226709B2 (en) * 1994-05-06 2001-11-05 帝人株式会社 Aramid - polyester laminate, the intermediate material and a process for their preparation
NL1000598C2 (en) 1995-06-20 1996-12-23 Dsm Nv Ballistic-resistant molded, and a method for the manufacture of the molding.
NL1001415C2 (en) 1995-10-13 1997-04-15 Dsm Nv Ballistic-resistant molded.
NL1003405C2 (en) 1996-06-24 1998-01-07 Dsm Nv Ballistic-resistant molded.
GB9620691D0 (en) * 1996-10-04 1996-11-20 Vantage Polymers Limited Olefin polymers
NL1010399C1 (en) 1998-10-26 2000-04-27 Dsm Nv Process for the production of a molded part.
US6191123B1 (en) * 1999-03-19 2001-02-20 Parker Hughes Institute Organic-arsenic compounds
DE10017493B4 (en) 2000-04-07 2009-02-26 Daimler Ag A method for producing a component with an internal tissue
GB0128405D0 (en) 2001-11-27 2002-01-16 Btg Int Ltd Process for fabricating polyolefin sheet
US7082731B2 (en) * 2002-09-03 2006-08-01 Murray Patz Insulated concrete wall system
NL1021805C2 (en) 2002-11-01 2004-05-06 Dsm Nv A process for the manufacture of a ballistic-resistant molded article.
US7578003B2 (en) 2004-01-01 2009-08-25 Dsm Ip Assets B.V. Ballistic-resistant article
CA2552081C (en) 2004-01-07 2012-07-17 Dsm Ip Assets B.V. Process for the manufacture of curved objects

Patent Citations (57)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3231650A (en) * 1960-03-11 1966-01-25 Phillips Petroleum Co Non-woven polyolefin fabrics and method of preparing same
US3689597A (en) * 1970-06-26 1972-09-05 Hercules Inc Polyphase compositions and process for their preparation
US3947537A (en) * 1971-07-16 1976-03-30 Exxon Research & Engineering Co. Battery separator manufacturing process
US4082731A (en) * 1973-02-12 1978-04-04 Avtex Fibers Inc. Method for producing a high modulus polyester yarn
US3962205A (en) * 1973-03-06 1976-06-08 National Research Development Corporation Polymer materials
US3884521A (en) * 1973-09-24 1975-05-20 Moore Alvin E Light-weight, durable, land-traversing vehicle
US4287149A (en) * 1973-10-03 1981-09-01 National Research Development Corp. Process for the production of polymer materials
US3997386A (en) * 1974-05-31 1976-12-14 Mitsubishi Jukogyo Kabushiki Kaisha Method for bonding thermoplastic high molecular weight materials
US4048364A (en) * 1974-12-20 1977-09-13 Exxon Research And Engineering Company Post-drawn, melt-blown webs
US4525564A (en) * 1975-11-05 1985-06-25 National Research Development Corporation High modulus, low creep strain polyalkene polymer materials
US4647640A (en) * 1975-11-05 1987-03-03 National Research Development Corporation Polymer materials
US4013816A (en) * 1975-11-20 1977-03-22 Draper Products, Inc. Stretchable spun-bonded polyolefin web
US4091140A (en) * 1976-05-10 1978-05-23 Johnson & Johnson Continuous filament nonwoven fabric and method of manufacturing the same
US4110391A (en) * 1976-07-31 1978-08-29 Ruhrchemie Aktiengesellschaft Process for the manufacture of molded articles from polyolefins with molecular weights of at least one million
US4285748A (en) * 1977-03-11 1981-08-25 Fiber Industries, Inc. Selfbonded nonwoven fabrics
US4228118A (en) * 1977-11-03 1980-10-14 Monsanto Company Process for producing high tenacity polyethylene fibers
US4191718A (en) * 1977-12-19 1980-03-04 Ford Motor Company Thick section compression molded composites
US4234536A (en) * 1978-09-27 1980-11-18 Thiel Alfons W Method for the manufacture of thin-walled shaped articles of crystalline thermoplastic material
US4413110A (en) * 1981-04-30 1983-11-01 Allied Corporation High tenacity, high modulus polyethylene and polypropylene fibers and intermediates therefore
US4454270A (en) * 1981-12-14 1984-06-12 Ethyl Corporation Method and composition for preventing or suppressing discoloration in polyolefins
US4551296A (en) * 1982-03-19 1985-11-05 Allied Corporation Producing high tenacity, high modulus crystalline article such as fiber or film
US4403012A (en) * 1982-03-19 1983-09-06 Allied Corporation Ballistic-resistant article
US4455273A (en) * 1982-09-30 1984-06-19 Allied Corporation Producing modified high performance polyolefin fiber
US4483727A (en) * 1983-02-07 1984-11-20 Celanese Corporation High modulus polyethylene fiber bundles as reinforcement for brittle matrices
US5135804A (en) * 1983-02-18 1992-08-04 Allied-Signal Inc. Network of polyethylene fibers
US4642153A (en) * 1983-05-31 1987-02-10 Allen Industries, Inc. Method and apparatus for making a sheet of material
US4668577A (en) * 1983-09-09 1987-05-26 Toyo Boseki Kabushiki Kaisha Polyethylene filaments and their production
US4938913A (en) * 1984-04-13 1990-07-03 National Research Development Corporation Solid phase deformation process
US4568581A (en) * 1984-09-12 1986-02-04 Collins & Aikman Corporation Molded three dimensional fibrous surfaced article and method of producing same
US4654262A (en) * 1985-04-10 1987-03-31 Itt Corporation Polyolefin resin surface preparation
US4923660A (en) * 1985-05-08 1990-05-08 Bernd Willenberg Process for the production of mouldings and films from thermotropic polymers
US4792426A (en) * 1985-05-28 1988-12-20 Usm Corporation Precision control of the thickness of heat-softenable material
US4931230A (en) * 1986-05-08 1990-06-05 Minnesota Mining And Manufacturing Company Method for preparing radiation resistant polypropylene articles
US4786348A (en) * 1987-01-05 1988-11-22 E. I. Du Pont De Nemours And Company Method of making transparent oriented sheets
US4948661A (en) * 1987-07-10 1990-08-14 C. H. Masland & Sons Glossy finish fiber reinforced molded product and processes of construction
US4990204A (en) * 1987-10-27 1991-02-05 The Dow Chemical Company Improved spunbonding of linear polyethylenes
US5006390A (en) * 1989-06-19 1991-04-09 Allied-Signal Rigid polyethylene reinforced composites having improved short beam shear strength
US5200131A (en) * 1990-04-09 1993-04-06 Mitsui Toatsu Chemicals, Inc. Method for molding syndiotactic polypropylene
US5032339A (en) * 1990-07-19 1991-07-16 E. I. Du Pont De Nemours And Company Process for shaping fiber reinforced thermoplastic articles
US6017834A (en) * 1991-03-07 2000-01-25 Btg International Limited Monoliyhic polymeric product
US5628946A (en) * 1991-03-07 1997-05-13 British Technology Group Limited Process for producing polymeric materials
US6277773B1 (en) * 1991-03-07 2001-08-21 Btg International Limited Polymeric materials
US5244482A (en) * 1992-03-26 1993-09-14 The University Of Tennessee Research Corporation Post-treatment of nonwoven webs
US5514448A (en) * 1992-07-22 1996-05-07 Mitsui Toatsu Chemicals, Inc. Laminated molding
US5324576A (en) * 1993-08-25 1994-06-28 Minnesota Mining And Manufacturing Company Polyolefin meltblown elastic webs
US5498129A (en) * 1994-05-04 1996-03-12 Eurocopter France Counter-torque device with ducted tail rotor and ducted flow-straightening stator, for helicopters
US5879607A (en) * 1994-05-11 1999-03-09 Raytheon Ti Systems & University Of Massachusetts Method of making a protective coating material
US5688426A (en) * 1995-06-07 1997-11-18 The Boeing Company Hybrid metal webbed composite beam
US20040213977A1 (en) * 1996-01-15 2004-10-28 Btg International Limited Compacted biomaterials
US20050170730A1 (en) * 1996-01-15 2005-08-04 Btg International Limited Compacted biomaterials
US6458727B1 (en) * 1996-10-04 2002-10-01 University Of Leeds Innovative Limited Olefin polymers
US6312638B1 (en) * 1996-10-04 2001-11-06 Btg International Process of making a compacted polyolefin article
US6328923B1 (en) * 1996-10-04 2001-12-11 Btg International Limited Process of making a compacted polyolefin article
US6132657A (en) * 1998-06-29 2000-10-17 Polyeitan Composites Ltd. Process for producing polymeric materials
US6482343B1 (en) * 1999-06-28 2002-11-19 Polyeitan Composites Ltd. Polymeric materials and process for producing same
US20040185732A1 (en) * 2001-05-09 2004-09-23 Bonner Mark James Polyolefin sheet
US20040169304A1 (en) * 2001-06-15 2004-09-02 Ward Ian M Amorphous polymer article

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100078439A1 (en) * 2006-12-06 2010-04-01 Franciscus Antonius Henri Janssen Use of a composite material as a barrier under cryogenic conditions
US8678225B2 (en) 2006-12-06 2014-03-25 Shell Oil Company Use of a composite material as a barrier under cryogenic conditions

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