WO1989001075A1 - Compositions for thermoplastic sheet manufactured by a wet process - Google Patents

Compositions for thermoplastic sheet manufactured by a wet process Download PDF

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Publication number
WO1989001075A1
WO1989001075A1 PCT/FR1988/000404 FR8800404W WO8901075A1 WO 1989001075 A1 WO1989001075 A1 WO 1989001075A1 FR 8800404 W FR8800404 W FR 8800404W WO 8901075 A1 WO8901075 A1 WO 8901075A1
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WO
WIPO (PCT)
Prior art keywords
constituent
parts
fibers
composition according
composition
Prior art date
Application number
PCT/FR1988/000404
Other languages
French (fr)
Inventor
Pierre Fredenucci
Christophe Chartier
Original Assignee
Societe Française Exxon Chemical
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by Societe Française Exxon Chemical filed Critical Societe Française Exxon Chemical
Priority to BR888807638A priority Critical patent/BR8807638A/en
Priority to KR1019890700589A priority patent/KR890701843A/en
Publication of WO1989001075A1 publication Critical patent/WO1989001075A1/en

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Classifications

    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
    • D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
    • D21H13/36—Inorganic fibres or flakes
    • D21H13/38—Inorganic fibres or flakes siliceous
    • D21H13/40—Inorganic fibres or flakes siliceous vitreous, e.g. mineral wool, glass fibres
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21J—FIBREBOARD; MANUFACTURE OF ARTICLES FROM CELLULOSIC FIBROUS SUSPENSIONS OR FROM PAPIER-MACHE
    • D21J1/00—Fibreboard
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
    • D21H13/10—Organic non-cellulose fibres
    • D21H13/20—Organic non-cellulose fibres from macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
    • D21H13/24—Polyesters
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
    • D21H17/63—Inorganic compounds
    • D21H17/67—Water-insoluble compounds, e.g. fillers, pigments

Definitions

  • compositions for thermoplastic sheet produced by wet process are Compositions for thermoplastic sheet produced by wet process
  • the invention relates to paper compositions for forming a reinforced hot-stampable thermoplastic sheet into a finished product.
  • a sheet is known for example from documents EP-A-0039292 and FR-A-2507123, the teachings of which are incorporated here by reference.
  • compositions intended to form such a sheet mainly comprise fibers for reinforcing the product during manufacture (such as cellulose or the like), fibers for reinforcing the finished product (such as glass fibers or the like), a resin. thermoplastic in particulate form, optionally a binder (such as latex in aqueous dispersion or the like).
  • the compositions can also comprise mineral fillers, essentially to reinforce the finished product by replacing part of the reinforcing fibers at a lower cost.
  • the process for manufacturing the sheet from the papermaking composition is a conventional papermaking process such as that described in the documents mentioned above, with passage through a papermaking machine, for example of the Fourdrinier type with flat table or inclined cloth.
  • the wet process involves the formation of an aqueous suspension comprising polymeric particles, fibers such as glass fibers which reinforce the finished products, and manufacturing additives.
  • the suspension is then deposited in a thin layer on a moving canvas through which it drips, possibly under vacuum, to leave a wet sheet of particles and fibers.
  • the sheet then passes through heating means such as an infrared oven or hot air jets. Once dried, the sheet called wet-made sheet is densified by hot pressing or molding to form a fiber-reinforced polymer (glass) product.
  • the compositions had to try to meet a number of criteria.
  • the criteria for a good composition with regard to the transformation of the sheet thus obtained are: a good suitability for reheating said sheet at a temperature higher than that of the melting point of the thermoplastic resin,
  • the criterion of a good composition vis-à-vis the finished product produced by transformation of the heated sheet is, for industrial applications in progress, that the elements necessary for the manufacture of the sheet (fibers and additives), do not not oppose obtaining good physical properties of said finished product.
  • the market for processors and users of plastic products, more particularly in the automobile industry is looking for materials which make it possible to obtain parts with a good surface appearance.
  • the criteria for a composition that meets this requirement are: - to allow the most regular surface finish possible,
  • the object of the invention is therefore to propose paper compositions meeting all the criteria listed above and more specifically intended to form a finished product of appearance meeting relatively high quality requirements, for example CLASS A surface finish for visible parts of automobile bodywork.
  • a wet fibrous sheet composition suitable for being molded into a reinforced thermoplastic product, comprising fibers for reinforcing the composition during manufacture, fibers for reinforcing the molded product, and a thermoplastic resin, said composition comprising in parts by dry weight (based on 100 parts of the first, second and third constituents combined): a) from 3 to 15 parts of a first constituent consisting of reinforcing fibers of the composition during its manufacture b) an amount reinforcing a second fibrous component effective for reinforcing the thermoplastic product formed by hot molding of the fibrous composition, and c) the remainder in parts of a third constituent consisting of thermoplastic polyester fibers, the first constituent having a temperature of fusion or degradation greater than that of the third constituent,
  • the proportions of the first, second and third constituents can vary independently within very wide limits, depending on the balance of the various properties such as the mechanical strength of the final product, the workability of the paper composition at the wet and dry state (melted), the moldability of the composition and the water absorption capacity of the molded product.
  • the latter provides a method of manufacturing a product molded from such a fibrous sheet composition, comprising preheating the sheet to a temperature below the melting temperature or ⁇ e degradation of the first constituent, but higher than the melting temperature of the third constituent so as to melt the third constituent but to retain the effect of reinforcement of the first component, and, in a press, molding the heated sheet under pressure and at a temperature below the melting temperature of the third component so as to form the desired molded product.
  • the preheating temperature is at least 30 ° C higher than the melting temperature of the third component.
  • the first component serves to provide the resistance of the molten sheet during the manipulation associated with the pressing step, for example during the transfer from the heating zone to the press, which can also be heated to improve the control of the cooling of the product. .
  • the reinforcing fibers of the product in production are mineral or organic fibers whose physical structure is identical or close to that of cellulose, that is to say of irregular shape with a high specific surface. Thus they contribute to the cohesion of the wet and dry sheet during the passage through a paper machine, then during the handling and cutting of the dry sheet, and oppose the withdrawal of the thermoplastic material during drying.
  • these fibers for reinforcing the product in manufacture preferably have a melting or degradation temperature of at least 20 ° C. higher than the transformation temperature of the polyester fibers used (for example, greater than 310 ° C. when the thermoplastic is PETP).
  • transformation is understood to mean the technique by which the sheet containing the first, second and third components is transformed into a thermoplastic finished product with improved mechanical properties (because of the second component). So, typically, the sheet is subjected to a high temperature such that the third constituent polyester melts. It is at this stage, as well as during the wet phase of the manufacturing process, that the importance of the first constituent is understood: without it, the molten thermoplastic polyester would creep and be unmanageable. In the presence of the second constituent, the sheet retains its integrity and can be transported to the molding station where it is subjected to pressure and cooled, so that the polyester cools in a continuous matrix in which the fibers of the second reinforcing constituent are homogeneously dispersed.
  • the molding can be done in flat sheet (also called plate or blank) which can be used as it is, or molded into an article of more complex shape; or the molding can be directly done in three-dimensional article.
  • first and second fibrous constituents give different reinforcement to the sheet or to the final product.
  • the first component is used to hold together the fibers of the second and third components in the wet or dry state and not melted, and to hold together the fibers of the second component and the thermoplastic matrix. when the polyester is in the molten state.
  • the first constituent is preferably in fibrillated form, which improves the capacity for entanglement. It is preferable not to use a binder during the wet stage of the manufacture of the sheet.
  • the fibers of the second constituent are intended to reinforce the final molded product and therefore have a high modulus of elasticity, like that of glass fibers.
  • the sheet has insufficient cohesion during manufacture and reheating.
  • the composition has reduced moldability and the molded product becomes sensitive to humidity and therefore loses dimensional stability.
  • the first constituent which, as has been said, is advantageously cellulose, and ideally a cellulose which has been refined to an SR degree of between 15 and 65, is present in the composition in amounts ranging from 4 to 8 parts by weight, for 100 parts by weight of the first, second and third constituents combined, and even more preferably from 4.5 to 6 parts by weight.
  • the second component is a fibrous material which provides reinforcement for the hot-pressed end product.
  • the reinforcing fibers of the finished product are advantageously glass fibers, of length less than 50 mm and even preferably of 25 mm.
  • the glass fibers have a length of between 6 and 25 mm, and a diameter of 9 to 15 micrometers, and, more preferably, from 10 to 12 micrometers.
  • Other fibers, alone or in mixture and also dispersed in the unit state, are carbon fibers, metallic or metallized fibers, mineral fibers (rock wool, ceramics, boron, etc.) or organic fibers ( carbon, polyaramides, polycarbonates, etc.).
  • the proportion of the second constituent present in the composition of the invention can vary to balance the moldability and mechanical strength properties required for the final product.
  • a high concentration results in good mechanical strength but can affect moldability, while a low concentration gives good moldability but reduces mechanical strength.
  • the composition comprises between 15 and 40 parts of fibers of the second constituent (based on 100 parts of the first, second and third constituents), and more preferably, from 18 to 27 parts by weight, and even more preferably from 21 to 26 parts by weight.
  • thermoplastic polyester is advantageously polyethylene terephthalate (PETP), although other polyalkylene terephthalates and other fiber-forming polyesters can be used. It is particularly suitable because its melting temperature of 240-250 ° C allows it to withstand the paint lines of automobile production lines, where the temperature approaches 140 ° C-160 ° C.
  • PETP polyethylene terephthalate
  • the polyester in the paper composition is in the form of microfibers or fibers, and preferably the fibers have a length of 3 to 6 mm. It has in fact been found that it is much more advantageous to use thermoplastic fibers rather than thermoplastic powders because the distribution of the resin in the sheet is more regular. Another advantage is that the speed of drainage of the suspension during the formation of the sheet on the canvas is much greater, which makes it possible, compared to a composition with powder, to manufacture faster and / or to dilute more to better disperse the reinforcing fibers.
  • the sheet after drying although having with fibers a lower density than with powders, therefore a greater "content" in air, presents a reduced press preheating time, which is surprising when you consider that the air present in the product is a poor conductor of heat.
  • compositions of the present invention can advantageously be compared to those taught in document WO-A-87 04476 (Battelle Memorial Institute), and which contain a hot-melt polymer component in the form of particles rather than fibers.
  • the amount of polyester in the composition depends on the amounts of the first and second constituents of course, but preferably ranges from 45 to 85 parts by weight, more preferably from 58 to 79 and even more preferably from 65 to 75 parts by weight (based on 100 parts of the first, second and third constituents).
  • the fibers of the first constituent have a melting or degradation temperature higher than that of the third constituent, so as to provide resistance to the composition in the preheated state, immediately before molding or passing through hot final.
  • the first constituent has a melting or degradation temperature higher by at least 50 ° C, and more preferably at least 65 ° C, than that of the third constituent.
  • compositions of the invention may also contain fillers.
  • the fillers are all the usual fillers, and in particular carbonates, talc, etc.
  • the fillers are preferably present in amounts of up to 45 parts by weight (based on 100 parts of the first, second and third constituents), for example from 20 to 45 parts by weight.
  • the composition may also contain the additives or adjuvants necessary for the manufacture, the processing of the sheet or the use of the molded products.
  • additives or adjuvants necessary for the manufacture, the processing of the sheet or the use of the molded products.
  • these there may be mentioned: dyes, antioxidants, lubricants, mold release or slip agents, peroxides, antistatic agents, nucleating agents, plasticizers, pigments, flocculants, retention agents , dispersants, flame retardants, water repellents, coupling agents, adhesion primers, anti UV agents etc.
  • IMC in mold coating
  • Table I the passing characteristics of tests 1 to 23 are reported on a pilot paper machine.
  • the first column indicates the test number.
  • the second column indicates the grammage of the sheet.
  • the third column indicates the position of the water line with reference to the corresponding chainline number, this number being, at equal dilution, the higher the less the composition drips.
  • the fourth column indicates the dilution, that is to say the water flow to bring to maintain the water line in its given position.
  • the combination of these two columns makes it possible to compare the speed of draining of the different compositions.
  • the fifth and sixth columns indicate the quantity of dry matter present respectively at the top of the machine and in the white water.
  • the seventh column gives the wet porosity, at the entrance to the dryer, measured in ml / min on a Bendtsen porosimeter.
  • the eighth column gives the dryness of the sheet at the outlet of the fabric, before drying.
  • the preferred mode of drying being the hot air passing through, the larger the values indicated in these last two columns and the more the composition allows a higher manufacturing speed and / or a higher weight / m 2 of the sheet.
  • Table II relates to the transformation of the sheets by preheating between the plates of a heating press at 300 ° C.
  • the first column indicates the test number.
  • the next four columns relate to the conditions of the preheating test and indicate respectively the number of batteries, the total number of formats, the size of the format (either rectangular of 15x11cm 2 , or round of 18cm in diameter) and their total weight.
  • the sixth column indicates the pressure calculated on the heated format stacks.
  • the seventh column reports the preheating time necessary to reach 290 ° C in the heart of the batteries.
  • Table III relates to plate molding tests. Two types of mold were used: the mold indicated no. 1 in the second column is a straight-edge plate mold, the bottom of which has a circular rib; mold # 2 is an ordinary deep plate mold.
  • the third column reports on the formats of the stack used to make the plates.
  • the fourth column concerns the visual aspect of the surface of the molded part (homogeneity and flatness).
  • the fifth column indicates the thickness of the plate, the sixth its density, the seventh the rate of ash.
  • the last three columns indicate respectively the tensile and bending stresses and the flexural modulus.
  • two values are indicated corresponding respectively to the ash rate for the fillers and for the glass fibers.
  • Tests 1 to 10 relate to uncharged compositions, and tests 11 to 20 to charged compositions.
  • Compositions with cellulose Tests 1 to 6 are compositions with cellulose, comprising in dry weight shares: cellulose fibers 10 glass fibers 21.5 PETP 68.5 The glass fibers are R18DX9 commercial fibers read by OWENS CORNING FIBERGLAS EUROPE under a length of 6mm and a diameter of 11 micrometers.
  • the aqueous suspension is prepared in a vat room as follows:
  • the cellulose fiber previously refined is introduced with stirring to a degree SR of between 15 and 65, particularly 50, and at a concentration of the order from 10 to 50g / l, especially around 30g / l.
  • the polyester fiber in the commercial state is added to the cellulose
  • the glass fiber dispersing agent namely for the fibers used a cationic dispersant based on Cartaspers DSI fatty acids (registered trademark of SAND0Z) at a rate of 10% commercial compared to the dry glass fiber, - finally, fiberglass is added last in the commercial state.
  • Cartaspers DSI fatty acids registered trademark of SAND0Z
  • PETP is a polyester T 100 from RHONE POULENC, in 6mm and 3.3 dtex fibers
  • Test n ° 2 PETP is a polyester T 100 from RHONE POULENC, in 3mm and 17 dtex fibers
  • n ° 3 PETP is a GRILON NV2 polyester from GRILENE, in 6mm and 3.3 dtex fibers
  • PETP is a polyester T 100 from RHONE POULENC in powder size less than 300 micrometers.
  • test No. 1 in Table I Comparing with test No. 1 in Table I, we see the very clear advantage of the composition with fibers with regard to drainage. However, the porosity is close, which is surprising. Furthermore, while the density of test No. 1 indicates a Air "content" higher than that of test 4, it can be seen in Table II that the preheating time is nevertheless lower, which is surprising and advantageous. On the other hand, the mechanical characteristics of the base (Table III) are comparable between test 1 and test 4, which is normal insofar as the polyester has been melted, and is therefore no longer dependent on the form in which it was originally introduced.
  • Test # 5 PETP is a 6438 polyester from Eastman Kodak, with an average particle size of 200 micrometers. This test confirms the previous one.
  • Table I shows a very slow drainage, in Table II a very long preheating time and in Table III a high ash rate indicating a low retention of the powdered PETP, which can justify the relatively poorer characteristics. Finally, note the bad appearance of the molded plate, linked to the very long preheating time leading to surface degradation of the material. Test # 6
  • PETP is a polyester supplied by ENKA and ground to a particle size of less than 300 micrometers.
  • the ash rate is still quite high.
  • thermoplastic fibers therefore allows, compared to powders, better machinability, greater productivity and greatly facilitated processing.
  • PETP Fibers T 900 from Rhone Poulenc 3.3 dtex, 3mm 76.1 parts Such a composition results in a product which cannot be properly drawn on an industrial paper machine which is partly wet and partly dry, due to the lack of cohesion and the high shrinkage during drying.
  • a very strong creep has been indicated in table II: the material flows and requires the ball to be folded up; the material cools. The process is not industrial.
  • test 7 is repeated, this time adding as fibers with a high specific surface, a synthetic polyolefin paste.
  • glass fibers (as in test 7) 22.4 parts PETP (as in test 7) 71.2 parts
  • Pulpex EA has fibers from 0.2 to 1.2 mm long and 10 to 20 micrometers in diameter.
  • Test n ° 9 It uses the composition of test 8 but under different preheating conditions to try to alleviate the problem encountered during the previous test.
  • test 10 contains cellulose and the same PETP T900 polymer as test 7.
  • the composition is as follows: Cellulose 10 parts
  • the slightly branched T900 polymer is a poorer grade of polymer in terms of mechanical resistance than the linear T100, which largely explains the drop in characteristics compared to test No. 1.
  • PETP fibers or powder
  • compositions with PETP fibers The filler used is a Millicarb carbonate marketed by OMYA.
  • the mineral filler is introduced into the refined cellulose before the polyester.
  • a usual retention agent at the top of the machine. Good results have been obtained with a high molecular weight polyacrylamide at a rate of 0.2% relative to the dry matter.
  • the fibers are a PETP T100 from Rhone Poulenc, 6mm, 3.3 dtex. As in test 11, there is a reduction in wrinkles on the plates compared to the uncharged compositions. Test n ° 14 The fibers are a PETP of MONTEFIBRE, 6mm in length.
  • the reduction in wrinkles is less marked than with Rhone Poulenc's PETP and the rate of ash in charges indicates a problem of retention of the charge.
  • Test n ° 15 The fibers are PETP DACRON fibers from DUPONT DE NEMOURS, D157N, 6mm, 7 dtex.
  • This test shows, as with the fibers, an improvement in appearance compared to test 4 but with a marked reduction in drainage and an increase in the preheating time compared to test 11.
  • the powder is a PETP 64-38 from Kodak with an average particle size of 200 micrometers.
  • Wrinkles are similar to those of Rhone Poulenc fiber compositions, but there are more dots.
  • compositions with PETP fibers since here the preheating time is reduced due to the lower quantity of material. 2.3. Compositions with other charges
  • the charge is Millicarb OMYA carbonate with an average particle size of 1 to 2 micrometers.
  • Test No. 19 The charge is carbonate B038 from Blanc Minéraux de Paris, with a particle size of 10 to 12 micrometers.
  • Test No. 20 The charge is talc (hydrated magnesium silicate) No. 2 of Talcs from Luzenac, with an average particle size of 12 micrometers.
  • PETP T100 from Rhone Poulenc in 6mm and 17 dtex fibers and R18DX9 glass fibers marketed by OWENS CORNING FIBERGLAS EUROPE of 6mm and 11 micrometers.
  • composition with 5 parts of cellulose allows correct passage on a paper machine and has sufficient strength to allow handling, cutting of the dry sheet and preheating without material creep.
  • the moldability values grouped in the table III represent the distance in grades traveled by the material in a circular orientation.
  • the diagram in annex shows the plate 1, one edge 2 of which can, during molding, stretch circumferentially in ear 3, the extension of which is measured by a graduation 4 of the mold.
  • compositions in which the cellulose content does not reach 3 parts by weight generally do not have suitable resistance to handling during the preheating which precedes the hot pressing.
  • the upper limit of the cellulose content As for the upper limit of the cellulose content, it is fixed by the value which leads to a generally unacceptable water absorption capacity in the final product, that is to say about 15 parts by weight. It is also at this value that the compositions become less easily moldable, especially for complicated shaped parts.

Abstract

A fibrous sheet composition manufactured by a wet process and suitable for making a reinforced thermoplastic moulded product comprises, in parts by dry weight (based on 100 parts of the first, second and third constituents combined): a) from 3 to 15 parts of a first constituent consisting of fibers for reinforcing the composition during its manufacture b) a quantity of a second reinforcing fibrous constituent which effectively reinforces the thermoplastic product formed by hot moulding of the fibrous composition, and c) the remainder in parts of a third constituent consisting of thermoplastic polyester fibers, the first constituent having a welding or degradation temperature higher than the welding temperature of the third constituent.

Description

Compositions pour feuille thermoplastique fabriquée par voie humide Compositions for thermoplastic sheet produced by wet process
L'invention concerne des compositions papetières, destinées à former une feuille thermoplastique renforcée estampable à chaud en un produit fini. Une telle feuille est connue par exemple par les documents EP-A-0039292 et FR-A-2507123 dont on incorpore ici les enseignements par référence.The invention relates to paper compositions for forming a reinforced hot-stampable thermoplastic sheet into a finished product. Such a sheet is known for example from documents EP-A-0039292 and FR-A-2507123, the teachings of which are incorporated here by reference.
Les compositions destinées à former une telle feuille comportent principalement des fibres de renforcement du produit en cours de fabrication (telles que de la cellulose ou analogue), des fibres de renforcement du produit fini (telles que des fibres de verres ou analogues), une résine thermoplastique sous forme particulaire, éventuellement un liant (tel que les latex en dispersion aqueuse ou analogue). Les compositions peuvent en outre comporter des charges minérales, essentiellement pour renforcer le produit fini en remplaçant à moindre coût une partie des fibres de renforcement.The compositions intended to form such a sheet mainly comprise fibers for reinforcing the product during manufacture (such as cellulose or the like), fibers for reinforcing the finished product (such as glass fibers or the like), a resin. thermoplastic in particulate form, optionally a binder (such as latex in aqueous dispersion or the like). The compositions can also comprise mineral fillers, essentially to reinforce the finished product by replacing part of the reinforcing fibers at a lower cost.
Le procédé de fabrication de la feuille à partir de la composition papetière est un procédé papetier classique tel que celui décrit dans les documents ci-dessus mentionnés, avec passage sur une machine papetière, par exemple du type Fourdrinier à table plate ou à toile inclinée.The process for manufacturing the sheet from the papermaking composition is a conventional papermaking process such as that described in the documents mentioned above, with passage through a papermaking machine, for example of the Fourdrinier type with flat table or inclined cloth.
En général, le procédé par voie humide comporte la formation d'une suspension aqueuse comprenant des particules polymériques, des fibres telles que les fibres de verre qui renforcent les produits finis, et des additifs de fabrication. La suspension est ensuite déposée en couche mince sur une toile en mouvement à travers laquelle elle s'égoutte, éventuellement sous vide, pour laisser une feuille humide de particules et de fibres. La feuille passe ensuite à travers des moyens de chauffage tels qu'un four à infra-rouges ou des jets d'air chaud. Une fois séchée, la feuille appelée feuille fabriquée par voie humide, subit une densification par pressage à chaud ou moulage de manière à former un produit en polymère renforcé de fibres (de verre). Jusqu'à maintenant, les compositions devaient essayer de satisfaire à un certain nombre de critères.In general, the wet process involves the formation of an aqueous suspension comprising polymeric particles, fibers such as glass fibers which reinforce the finished products, and manufacturing additives. The suspension is then deposited in a thin layer on a moving canvas through which it drips, possibly under vacuum, to leave a wet sheet of particles and fibers. The sheet then passes through heating means such as an infrared oven or hot air jets. Once dried, the sheet called wet-made sheet is densified by hot pressing or molding to form a fiber-reinforced polymer (glass) product. Until now, the compositions had to try to meet a number of criteria.
Les critères d'une bonne composition vis-à-vis du procédé sont notamment :The criteria for a good composition with regard to the process are in particular:
- conduire à la formation d'une feuille homogène et régulière, - permettre la vitesse de fabrication la plus rapide possible,- lead to the formation of a homogeneous and regular sheet, - allow the fastest possible production speed,
- conférer à la feuille une cohésion suffisante pour permettre son séchage, sa manipulation et sa transformation.- give the sheet sufficient cohesion to allow drying, handling and processing.
Les critères d'une bonne composition vis-à-vis de la transformation de la feuille ainsi obtenue sont : - une bonne aptitude au réchauffage de ladite feuille à une température supérieure à celle du point de fusion de la résine thermoplastique,The criteria for a good composition with regard to the transformation of the sheet thus obtained are: a good suitability for reheating said sheet at a temperature higher than that of the melting point of the thermoplastic resin,
- la moulabilité la plus élevée possible.- the highest possible moldability.
Enfin, le critère d'une bonne composition vis-à-vis du produit fini réalisé par transformation de la feuille réchauffée est, pour les applications industrielles en cours, que les éléments nécessaires à la fabrication de la feuille (fibres et additifs), ne s'opposent pas à l'obtention de bonnes propriétés physiques dudit produit fini. Or à présent, le marché ds transformateurs et utilisateurs de produits plastiques, plus particulièrement dans l'industrie automobile, recherche des matériaux permettant d'obtenir des pièces avec un bel aspect de surface. Les critères d'une composition répondant à cette exigence sont : - permettre l'état de surface le plus régulier possible,Finally, the criterion of a good composition vis-à-vis the finished product produced by transformation of the heated sheet is, for industrial applications in progress, that the elements necessary for the manufacture of the sheet (fibers and additives), do not not oppose obtaining good physical properties of said finished product. Now, the market for processors and users of plastic products, more particularly in the automobile industry, is looking for materials which make it possible to obtain parts with a good surface appearance. The criteria for a composition that meets this requirement are: - to allow the most regular surface finish possible,
- avoir une stabilité thermique compatible avec les chaînes industrielles de mise en peinture,- have thermal stability compatible with industrial painting lines,
- en toutes conditions atmosphériques, la meilleure stabilité dimensionnelle possible. Certains ont proposé d'améliorer l'aspect en apportant en surface une feuille ou un film ou une couche de composition différente de celle de la feuille de base mais ce type de solution est d'application très limitée car il interdit toute forme complexe. Le but de l'invention est donc de proposer des compositions papetières répondant à tous les critères ci-dessus énumérés et plus spécialement destinées à former un produit fini d'aspect répondant à des exigences relativement élevées de qualité, par exemple fini de surface CLASSE A pour des pièces visibles de carosserie automobile.- in all atmospheric conditions, the best possible dimensional stability. Some have proposed improving the appearance by providing a surface or a film or a layer of composition different from that of the base sheet, but this type of solution is of very limited application because it prohibits any complex form. The object of the invention is therefore to propose paper compositions meeting all the criteria listed above and more specifically intended to form a finished product of appearance meeting relatively high quality requirements, for example CLASS A surface finish for visible parts of automobile bodywork.
Selon la présente invention, on propose une composition de feuille fibreuse voie humide, adaptée pour être moulée en un produit thermoplastique renforcé, comprenant des fibres de renforcement de la composition pendant la fabrication, des fibres de renforcement du produit moulé, et une résine thermoplastique, ladite composition comprenant en parts en poids sec (basées sur 100 parts des premier, deuxième et troisième constituants combinés) : a) de 3 à 15 parts d'un premier constituant consistant en fibres de renforcement de la composition pendant sa fabrication b) une quantité de renforcement d'un second constituant fibreux efficace pour renforcer le produit thermoplastique formé par moulage à chaud de la composition fibreuse, et c) le reste en parts d'un troisième constituant consistant en fibres de polyester thermoplastique, le premier constituant ayant une température de fusion ou de dégradation supérieure à celle de fusion du troisième constituant,According to the present invention, there is provided a wet fibrous sheet composition, suitable for being molded into a reinforced thermoplastic product, comprising fibers for reinforcing the composition during manufacture, fibers for reinforcing the molded product, and a thermoplastic resin, said composition comprising in parts by dry weight (based on 100 parts of the first, second and third constituents combined): a) from 3 to 15 parts of a first constituent consisting of reinforcing fibers of the composition during its manufacture b) an amount reinforcing a second fibrous component effective for reinforcing the thermoplastic product formed by hot molding of the fibrous composition, and c) the remainder in parts of a third constituent consisting of thermoplastic polyester fibers, the first constituent having a temperature of fusion or degradation greater than that of the third constituent,
Comme on le décrira plus loin, les proportions des premier, deuxième et troisième constituants peuvent varier indépendamment dans de très larges limites, en fonction de l'équilibre des diverses propriétés telles que la résistance mécanique du produit final, la maniabilité de la composition papetière à l'état humide et sec (fondu), la moulabilité de la composition et la capacité d'absorption d'eau du produit moulé.As will be described below, the proportions of the first, second and third constituents can vary independently within very wide limits, depending on the balance of the various properties such as the mechanical strength of the final product, the workability of the paper composition at the wet and dry state (melted), the moldability of the composition and the water absorption capacity of the molded product.
Selon un autre aspect de l'invention, celle-ci propose un procédé de fabrication d'un produit moulé à partir d'une telle composition de feuille fibreuse, comprenant le préchauffage de la feuille à une température inférieure à la température de fusion ou αe dégradation du premier constituant, mais supérieure à la température de fusion du troisième constituant de manière à faire fondre le troisième constituant mais à conserver l'effet de renforcement du premier constituant, et, dans une presse, le moulage de la feuille chauffée sous pression et à température inférieure à la température de fusion du troisième constituant de manière à former le produit moulé désiré. De préférence, la température de préchauffage est d'au moins 30°C supérieure à la température de fusion du troisième constituant. Le premier constituant sert à procurer la résistance de la feuille fondue pendant la manipulation associée à l'étape de pressage, par exemple pendant le transfert de la zone de chauffage vers la presse, laquelle peut aussi être chauffée pour améliorer la maîtrise du refroidissement du produit.According to another aspect of the invention, the latter provides a method of manufacturing a product molded from such a fibrous sheet composition, comprising preheating the sheet to a temperature below the melting temperature or αe degradation of the first constituent, but higher than the melting temperature of the third constituent so as to melt the third constituent but to retain the effect of reinforcement of the first component, and, in a press, molding the heated sheet under pressure and at a temperature below the melting temperature of the third component so as to form the desired molded product. Preferably, the preheating temperature is at least 30 ° C higher than the melting temperature of the third component. The first component serves to provide the resistance of the molten sheet during the manipulation associated with the pressing step, for example during the transfer from the heating zone to the press, which can also be heated to improve the control of the cooling of the product. .
Les fibres de renforcement du produit en fabrication (c'est-à-dire le premier constituant) sont les fibres minérales ou organiques dont la structure physique est identique pu proche de celle de la cellulose, c'est-à-dire de forme irrégulière avec une surface spécifique élevée. Ainsi elles contribuent à la cohésion de la feuille humide et sèche lors du passage en machine papetière, puis lors de la manutention et de la découpe de la feuille sèche, et s'opposent au retrait de la matière thermo- plastique lors du séchage. Selon l'invention, ces fibres de renforcement du produit en fabrication ont de préférence une température de fusion ou de dégradation d'au moins 20°C supérieure à la température de transformation des fibres de polyester utilisées (par exemple, supérieure à 310° C lorsque la matière thermoplastique est du PETP).The reinforcing fibers of the product in production (that is to say the first constituent) are mineral or organic fibers whose physical structure is identical or close to that of cellulose, that is to say of irregular shape with a high specific surface. Thus they contribute to the cohesion of the wet and dry sheet during the passage through a paper machine, then during the handling and cutting of the dry sheet, and oppose the withdrawal of the thermoplastic material during drying. According to the invention, these fibers for reinforcing the product in manufacture preferably have a melting or degradation temperature of at least 20 ° C. higher than the transformation temperature of the polyester fibers used (for example, greater than 310 ° C. when the thermoplastic is PETP).
Ces fibres de par leur structure s'opposent également au fluage, c'est-à-dire à la désorganisation de la feuille et à l'écoulement de la résine durant l'opération de réchauffage d'un format ou d'un empilement de formats de ladite feuille avant de mouler ou de ce transformer en une plaque densifiée rigide.These fibers, by their structure, also oppose creep, that is to say the disorganization of the sheet and the flow of the resin during the reheating operation of a format or a stack of formats of said sheet before molding or transforming it into a rigid densified plate.
Dans le contexte de la présente invention, on entend par transformation la technique par laquelle la feuille contenant les premier, deuxième et troisième constituants, est transformée en un produit fini thermoplastique aux propriétés mécaniques améliorées (à cause du second constituant). Ainsi, de manière typique, la feuille est soumise à une température élevée telle que le troisième constituant polyester fond. C'est à ce stade, ainsi qu'au cours de la phase humide du procédé de fabrication, qu'on conçoit l'importance du premier constituant : sans lui, le polyester thermoplastique fondu fluerait et serait inmaniable. En présence du second constituant, la feuille conserve son intégrité et peut être transportée vers le poste de moulage où elle est soumise à pression et refroidie, de sorte que le polyester se refroidit en une matrice continue dans laquelle les fibres du second constituant de renforcement sont dispersées de façon homogène. Le moulage peut se faire en feuille plate (encore appelée plaque ou flan) qui peut être utilisée telle quelle, ou moulée en un article de forme plus complexe ; ou bien le moulage peut directement se faire en article tridimensionnel. On comprendra que les premiers et deuxième constituants fibreux donnent un renforcement différent à la feuille ou au produit final. Ainsi, le premier constituant sert à maintenir ensemble les fibres du deuxième et du troisième constituants à l'état humide ou sec et non fondu, et à maintenir ensemble les fibres du second constituant et la matrice thermoplastique. quand le polyester est à l'état fondu. C'est pourquoi le premier constituant est de préférence sous forme fibrillée, qui améliore la capacité à l'enchevêtrement. On préfère ne pas utiliser de liant lors de l'étape humide de la fabrication de la feuille. Au contraire, les fibres du deuxième constituant sont destinées à renforcer le produit moulé final et ont donc un module d'élasticité élevé, comme celui des fibres de verre.In the context of the present invention, transformation is understood to mean the technique by which the sheet containing the first, second and third components is transformed into a thermoplastic finished product with improved mechanical properties (because of the second component). So, typically, the sheet is subjected to a high temperature such that the third constituent polyester melts. It is at this stage, as well as during the wet phase of the manufacturing process, that the importance of the first constituent is understood: without it, the molten thermoplastic polyester would creep and be unmanageable. In the presence of the second constituent, the sheet retains its integrity and can be transported to the molding station where it is subjected to pressure and cooled, so that the polyester cools in a continuous matrix in which the fibers of the second reinforcing constituent are homogeneously dispersed. The molding can be done in flat sheet (also called plate or blank) which can be used as it is, or molded into an article of more complex shape; or the molding can be directly done in three-dimensional article. It will be understood that the first and second fibrous constituents give different reinforcement to the sheet or to the final product. Thus, the first component is used to hold together the fibers of the second and third components in the wet or dry state and not melted, and to hold together the fibers of the second component and the thermoplastic matrix. when the polyester is in the molten state. This is why the first constituent is preferably in fibrillated form, which improves the capacity for entanglement. It is preferable not to use a binder during the wet stage of the manufacture of the sheet. On the contrary, the fibers of the second constituent are intended to reinforce the final molded product and therefore have a high modulus of elasticity, like that of glass fibers.
On a trouvé que, dans les quantités préconisées, la cellulose répond parfaitement à ces objectifs et n'est pas du tout pénalisante, contrairement au préjugé généralement défavorable à son égard.It has been found that, in the quantities recommended, the cellulose perfectly meets these objectives and is not at all penalizing, contrary to the generally unfavorable prejudice against it.
En deçà de 3% du mélange fibreux, la feuille à une cohésion insuffisante à la fabrication et au réchauffage.Below 3% of the fibrous mixture, the sheet has insufficient cohesion during manufacture and reheating.
Au delà de 15% du mélange fibreux, la composition a une moulabilité réduite et le produit moulé devient sensible à l'humidité et donc perd de la stabilité dimensionnelle.Above 15% of the fibrous mixture, the composition has reduced moldability and the molded product becomes sensitive to humidity and therefore loses dimensional stability.
De préférence, le premier constituant, qui comme on l'a dit est avantageusement de la cellulose, et idéalement une cellulose qui a été raffinée à un degré SR compris entre 15 et 65, est présent dans la composition dans des quantités allant de 4 à 8 parts en poids, pour 100 parts en poids des premier, deuxième et troisième constituants combinés, et encore plus preferablement de 4,5 à 6 parts en poids. Ces proportions optimisent la moulabilité, la maniabilité et la capacité d'absorption d'eau du produit. Le second constituant est un matériau fibreux qui confère le renforcement du produit final pressé à chaud.Preferably, the first constituent, which, as has been said, is advantageously cellulose, and ideally a cellulose which has been refined to an SR degree of between 15 and 65, is present in the composition in amounts ranging from 4 to 8 parts by weight, for 100 parts by weight of the first, second and third constituents combined, and even more preferably from 4.5 to 6 parts by weight. These proportions optimize the moldability, the workability and the water absorption capacity of the product. The second component is a fibrous material which provides reinforcement for the hot-pressed end product.
Les fibres de renforcement du produit fini sont avantageusement les fibres de verre, de longueur inférieure à 50 mm et même de préférence à 25 mm. De préférence, les fibres de verre ont une longueur comprise entre 6 et 25 mm, et un diamètre de 9 à 15 micromètres, et, plus preferablement, de 10 à 12 micromètres. D'autres fibres, seules ou en mélange et également dispersées à l'état unitaire, sont les fibres de carbone, les fibres métalliques ou métallisées, les fibres minérales (laine de roche, céramiques, bore, etc.) ou les fibres organiques (carbone, polyaramides, polycarbonates, etc.).The reinforcing fibers of the finished product are advantageously glass fibers, of length less than 50 mm and even preferably of 25 mm. Preferably, the glass fibers have a length of between 6 and 25 mm, and a diameter of 9 to 15 micrometers, and, more preferably, from 10 to 12 micrometers. Other fibers, alone or in mixture and also dispersed in the unit state, are carbon fibers, metallic or metallized fibers, mineral fibers (rock wool, ceramics, boron, etc.) or organic fibers ( carbon, polyaramides, polycarbonates, etc.).
La proportion du second constituant présent dans la composition de l'invention peut varier pour équilibrer les propriétés de moulabilité et de résistance mécanique requises pour le produit final. Ainsi, une concentration élevée entraîne une bonne résistance mécanique mais peut nuire à la moulabilité, tandis qu'une concentration basse donne une bonne moulabilité mais diminue la résistance mécanique. C'est pour l'Homme du métier une opération relativement simple d'estimer pour une composition donnée quelle doit être la quantité de renforcement du second constituant en fibres. De préférence, la composition comprend entre 15 et 40 parts de fibres du second constituant (basées sur 100 parts des premier, deuxième et troisième constituants), et plus preferablement, de 18 à 27 parts en poids, et encore plus preferablement de 21 à 26 parts en poids. Le polyester thermoplastique (c'est-à-dire le troisième constituant) est avantageusement le polyéthylène téréphtalate (PETP) , quoique d'autres polyalkylènes téréphtalates et d'autres polyesters formant des fibres peuvent être utilisés. II convient particulièrement bien car sa température de fusion de 240-250° C lui permet de supporter les lignes de peinture des chaînes de fabrication automobile, où la température approche les 140° C-160° C.The proportion of the second constituent present in the composition of the invention can vary to balance the moldability and mechanical strength properties required for the final product. Thus, a high concentration results in good mechanical strength but can affect moldability, while a low concentration gives good moldability but reduces mechanical strength. It is for the skilled person a relatively simple operation to estimate for a given composition what should be the amount of reinforcement of the second fiber component. Preferably, the composition comprises between 15 and 40 parts of fibers of the second constituent (based on 100 parts of the first, second and third constituents), and more preferably, from 18 to 27 parts by weight, and even more preferably from 21 to 26 parts by weight. The thermoplastic polyester (ie the third constituent) is advantageously polyethylene terephthalate (PETP), although other polyalkylene terephthalates and other fiber-forming polyesters can be used. It is particularly suitable because its melting temperature of 240-250 ° C allows it to withstand the paint lines of automobile production lines, where the temperature approaches 140 ° C-160 ° C.
Selon l'invention, le polyester dans la composition papetière est sous forme de microfibres ou de fibres, et préférentiellement les fibres ont une longueur de 3 à 6 mm. On a en effet trouvé qu'il est nettement plus avantageux d'employer des fibres thermoplastiques plutôt que des poudres thermoplastiques car la répartition de la résine dans la feuille est plus régulière. Un autre intérêt est que la vitesse d'égouttage de la suspension lors de la formation de la feuille sur la toile, est beaucoup plus grande ce qui permet, par rapport à une composition avec poudre, de fabriquer plus vite et/ou de diluer plus afin de mieux disperser les fibres de renforcement. D'autre part, contrairement à ce que l'on aurait pu attendre, la feuille après séchage, bien qu'ayant avec des fibres une densité plus faible qu'avec des poudres, donc une "teneur" en air plus grande, présente un temps de préchauffage sous presse plus réduit, ce qui est en effet surprenant si l'on songe que l'air présent dans le produit est un mauvais conducteur de la chaleur.According to the invention, the polyester in the paper composition is in the form of microfibers or fibers, and preferably the fibers have a length of 3 to 6 mm. It has in fact been found that it is much more advantageous to use thermoplastic fibers rather than thermoplastic powders because the distribution of the resin in the sheet is more regular. Another advantage is that the speed of drainage of the suspension during the formation of the sheet on the canvas is much greater, which makes it possible, compared to a composition with powder, to manufacture faster and / or to dilute more to better disperse the reinforcing fibers. On the other hand, contrary to what one might have expected, the sheet after drying, although having with fibers a lower density than with powders, therefore a greater "content" in air, presents a reduced press preheating time, which is surprising when you consider that the air present in the product is a poor conductor of heat.
Les compositions de la présente invention peuvent avantageusement être comparées à celles qu'enseigne le document W0-A-87 04476 (Battelle Mémorial Institute), et qui contiennent un constituant polymérique thermofusible sous forme de particules plutôt que de fibres.The compositions of the present invention can advantageously be compared to those taught in document WO-A-87 04476 (Battelle Memorial Institute), and which contain a hot-melt polymer component in the form of particles rather than fibers.
La quantité de polyester dans la composition dépend des quantités des premier et deuxième constituants bien sûr, mais va de préférence de 45 à 85 parts en poids, plus preferablement de 58 à 79 et encore plus preferablement de 65 à 75 parts en poids (basées sur 100 parts des premier, second et troisième constituants). Selon l'invention, les fibres du premier constituant ont une température de fusion ou de dégradation supérieure à celle du troisième constituant, de manière à apporter de la résistance à la composition à l'état préchauffé, immédiatement avant le moulage ou le passage à chaud final. De préférence, le premier constituant a une température de fusion ou de dégradation supérieure d'au moins 50°C, et plus preferablement au moins 65°C, à celle du troisième constituant.The amount of polyester in the composition depends on the amounts of the first and second constituents of course, but preferably ranges from 45 to 85 parts by weight, more preferably from 58 to 79 and even more preferably from 65 to 75 parts by weight (based on 100 parts of the first, second and third constituents). According to the invention, the fibers of the first constituent have a melting or degradation temperature higher than that of the third constituent, so as to provide resistance to the composition in the preheated state, immediately before molding or passing through hot final. Preferably, the first constituent has a melting or degradation temperature higher by at least 50 ° C, and more preferably at least 65 ° C, than that of the third constituent.
Les compositions de l'invention peuvent aussi contenir des charges.The compositions of the invention may also contain fillers.
Selon l'invention, les charges sont toutes les charges usuelles en la matière , et notamment des carbonates, le talc, etc.According to the invention, the fillers are all the usual fillers, and in particular carbonates, talc, etc.
Les charges, s'il y en a, sont de préférence présentes dans des quantités allant jusqu'à 45 parts en poids (basées sur 100 parts des premier, deuxième et troisième constituants), par exemple de 20 à 45 parts en poids.The fillers, if any, are preferably present in amounts of up to 45 parts by weight (based on 100 parts of the first, second and third constituents), for example from 20 to 45 parts by weight.
Outre ces matières premières principales, la composition peut également comporter les additifs ou adjuvants nécessaires à la fabrication, à la transformation de la feuille ou à l'utilisation des produits moulés. Parmis ceux-ci, on peut citer : les colorants, les antioxydants, les lubrifiants, les agents de démoulage ou de glissement, les peroxydes, les agents antistatiques, les agents nucléants, les plastifiants, les pigments , les floculants , les agents de rétention , les dispersants, les ignifugeants, les hydrofugeants, les agents de couplage, les primers d'adhérence, les agents anti U.V. etc.In addition to these main raw materials, the composition may also contain the additives or adjuvants necessary for the manufacture, the processing of the sheet or the use of the molded products. Among these, there may be mentioned: dyes, antioxidants, lubricants, mold release or slip agents, peroxides, antistatic agents, nucleating agents, plasticizers, pigments, flocculants, retention agents , dispersants, flame retardants, water repellents, coupling agents, adhesion primers, anti UV agents etc.
De plus, il est possible d'améliorer l'état de surface du matériau par ajout d'IMC ("in mould coating"). Cette technique "in mould coating" consiste à injecter à l'intérieur du moule une couche de vernis (thermodur en général) qui améliore l'état de surface et permet l'accrochage ultérieur des couches de peinture lorsqu'il s'agit par exemple de pièces de carrosseries.In addition, it is possible to improve the surface condition of the material by adding IMC ("in mold coating"). This "in-mold coating" technique consists in injecting a layer of varnish (thermoset in general) inside the mold which improves the surface condition and allows the subsequent attachment of the paint layers when, for example. body parts.
L'intérêt et les divers aspects de l'invention ressortiront à la lecture des tableaux I à III en annexe. Ces tableaux regroupent les caractéristiques et mesures de 23 essais pratiqués sur différentes compositions, chargées ou non chargées, incorporant le polyester en poudre comme dans l'art antérieur ou sous forme de fibres selon l'invention.The interest and the various aspects of the invention will emerge on reading Tables I to III in the appendix. These tables group together the characteristics and measures of 23 tests carried out on different compositions, charged or uncharged, incorporating the polyester powder as in the prior art or in the form of fibers according to the invention.
Dans le tableau I, on a reporté les caractéristiques de passage des essais 1 à 23 sur une machine papetière pilote. La première colonne indique le numéro d'essai. La seconde colonne indique le grammage de la feuille. La troisième colonne indique la position de la ligne d'eau en référence au numéro de pontuseau correspondant, ce nombre étant, à dilution égale, d'autant plus élevé que la composition s'egoutte moins.In Table I, the passing characteristics of tests 1 to 23 are reported on a pilot paper machine. The first column indicates the test number. The second column indicates the grammage of the sheet. The third column indicates the position of the water line with reference to the corresponding chainline number, this number being, at equal dilution, the higher the less the composition drips.
La quatrième colonne indique la dilution, à savoir le débit d'eau à apporter pour maintenir la ligne d'eau dans sa position donnée. L'association de ces deux colonnes permet de comparer la rapidité d'égouttage des différentes compositions.The fourth column indicates the dilution, that is to say the water flow to bring to maintain the water line in its given position. The combination of these two columns makes it possible to compare the speed of draining of the different compositions.
Les cinquième et sixième colonnes indiquent la quantité de matière sèche présente respectivement en tête de la machine et dans les eaux blanches. La septième colonne donne la porosité humide, à l'entrée de la sécherie, mesurée en ml/min sur un porosimètre Bendtsen.The fifth and sixth columns indicate the quantity of dry matter present respectively at the top of the machine and in the white water. The seventh column gives the wet porosity, at the entrance to the dryer, measured in ml / min on a Bendtsen porosimeter.
La huitième colonne donne la siccité de la feuille en sortie de toile, avant séchage.The eighth column gives the dryness of the sheet at the outlet of the fabric, before drying.
Le mode préféré de séchage étant l'air chaud traversant, plus les valeurs indiquées dans ces deux dernières colonnes sont grandes et plus la composition permet une vitesse de fabrication élevée et/ou un poids /m2 de la feuille plus fort.The preferred mode of drying being the hot air passing through, the larger the values indicated in these last two columns and the more the composition allows a higher manufacturing speed and / or a higher weight / m 2 of the sheet.
Enfin, la dernière colonne indique la densité de la feuille après séchage 15 minutes dans une étuve à 80°C. Le tableau II se rapporte à la transformation des feuilles par préchauffage entre plateaux d'une presse chauffante à 300°C.Finally, the last column indicates the density of the sheet after drying for 15 minutes in an oven at 80 ° C. Table II relates to the transformation of the sheets by preheating between the plates of a heating press at 300 ° C.
La première colonne indique le numéro d'essai. Les quatre colonnes suivantes concernent les conditions de l'essai de préchauffage et indiquent respectivement le nombre de piles, le nombre total de formats, la dimension du format (soit rectangulaire de 15x11cm2, soit rond de 18cm de diamètre) et leur poids total.The first column indicates the test number. The next four columns relate to the conditions of the preheating test and indicate respectively the number of batteries, the total number of formats, the size of the format (either rectangular of 15x11cm 2 , or round of 18cm in diameter) and their total weight.
La sixième colonne indique la pression calculée sur les piles de formats réchauffés.The sixth column indicates the pressure calculated on the heated format stacks.
La septième colonne rapporte la durée du préchauffage nécessaire pour atteindre 290°C au coeur des piles.The seventh column reports the preheating time necessary to reach 290 ° C in the heart of the batteries.
La dernière colonne recueille, le cas échéant, des observations sur le fluage observé au cours du préchauffage. Enfin le tableau III concerne des essais de moulage en assiette. Deux types de moule ont été utilisés : le moule indiqué n°l dans la seconde colonne est un moule en assiette à bord droit dont le fond comporte une nervure circulaire ; le moule n°2 est un moule en assiette creuse ordinaire. La troisième colonne rapporte des indications sur les formats de l'empilage utilisés pour fabriquer les assiettes.The last column collects, if necessary, observations on the creep observed during preheating. Finally, Table III relates to plate molding tests. Two types of mold were used: the mold indicated no. 1 in the second column is a straight-edge plate mold, the bottom of which has a circular rib; mold # 2 is an ordinary deep plate mold. The third column reports on the formats of the stack used to make the plates.
La quatrième colonne concerne l'aspect visuel de la surface de la pièce moulée (homogénéité et planéïté).The fourth column concerns the visual aspect of the surface of the molded part (homogeneity and flatness).
La cinquième colonne indique l'épaisseur de l'assiette, la sixième sa densité, la septième le taux de cendres. Les trois dernières colonnes indiquent respectivement les contraintes de traction et de flexion et le module de flexion. Pour les compositions chargées, on indique deux valeurs correspondant respectivement au taux de cendres pour les charges et pour les fibres de verre.The fifth column indicates the thickness of the plate, the sixth its density, the seventh the rate of ash. The last three columns indicate respectively the tensile and bending stresses and the flexural modulus. For the loaded compositions, two values are indicated corresponding respectively to the ash rate for the fillers and for the glass fibers.
Les essais 1 à 10 portent sur des compositions non chargées, et les essais 11 à 20 sur des compositions chargées. 1. COMPOSITIONS NON CHARGEES 1.1. Compositions avec cellulose Les essais 1 à 6 sont des compositions avec cellulose, comportant en parts de poids sec : fibres de cellulose 10 fibres de verre 21,5 PETP 68,5 Les fibres de verres sont des fibres R18DX9 commercia lisées par OWENS CORNING FIBERGLAS EUROPE sous une longueur de 6mm et un diamètre de 11 micromètres.Tests 1 to 10 relate to uncharged compositions, and tests 11 to 20 to charged compositions. 1. UNLOADED COMPOSITIONS 1.1. Compositions with cellulose Tests 1 to 6 are compositions with cellulose, comprising in dry weight shares: cellulose fibers 10 glass fibers 21.5 PETP 68.5 The glass fibers are R18DX9 commercial fibers read by OWENS CORNING FIBERGLAS EUROPE under a length of 6mm and a diameter of 11 micrometers.
Selon un mode opératoire préférentiel, la suspension aqueuse est préparée dans un cuvier de la façon suivante : On introduit sous agitation la fibre de cellulose préalablement raffinée à un degré SR compris entre 15 et 65, particulièrement 50, et à une concentration de l'ordre de 10 à 50g/l, particulièrement environ 30g/l.According to a preferred operating method, the aqueous suspension is prepared in a vat room as follows: The cellulose fiber previously refined is introduced with stirring to a degree SR of between 15 and 65, particularly 50, and at a concentration of the order from 10 to 50g / l, especially around 30g / l.
- on ajoute dans la cellulose la fibre de polyesters en l'état commercial,- the polyester fiber in the commercial state is added to the cellulose,
- puis l'agent dispersant de la fibre de verre, à savoir pour les fibres utilisées un dispersant cationique à base d'acides gras Cartaspers DSI (marque déposée de SAND0Z) à raison de 10% commercial par rapport à la fibre de verre sèche, - enfin, la fibre de verre est ajoutée en dernier dans l'état commercial.- then the glass fiber dispersing agent, namely for the fibers used a cationic dispersant based on Cartaspers DSI fatty acids (registered trademark of SAND0Z) at a rate of 10% commercial compared to the dry glass fiber, - finally, fiberglass is added last in the commercial state.
1.1.1, Essais avec fibres PETP selon l'invention Essai n°11.1.1, Tests with PETP fibers according to the invention Test n ° 1
Le PETP est un polyester T 100 de RHONE POULENC, en fibres de 6mm et 3,3 dtexPETP is a polyester T 100 from RHONE POULENC, in 6mm and 3.3 dtex fibers
Essai n°2 Le PETP est un polyester T 100 de RHONE POULENC, en fibres de 3mm et 17 dtexTest n ° 2 PETP is a polyester T 100 from RHONE POULENC, in 3mm and 17 dtex fibers
Essai n°3 Le PETP est un polyester GRILON NV2 de GRILENE, en fibres de 6mm et 3,3 dtexTest n ° 3 PETP is a GRILON NV2 polyester from GRILENE, in 6mm and 3.3 dtex fibers
1.1.2. Essais comparatifs avec poudre PETP Essai n°41.1.2. Comparative tests with PETP powder Test n ° 4
Le PETP est un polyester T 100 de RHONE POULENC en poudre de granulométrie inférieure à 300 micromètres.PETP is a polyester T 100 from RHONE POULENC in powder size less than 300 micrometers.
En comparant avec l'essai n°1 dans le tableau I, on constate l'avantage très net de la composition avec fibres en ce qui concerne l'égouttage. Néanmoins la porosité est voisine, ce qui est surprenant. Par ailleurs, alors que la densité de l'essai n°l indique une "teneur" en air supérieure à celle de l'essai 4, on voit sur le tableau II que la durée de préchauffage est malgré tout plus faible, ce qui est surprenant et avantageux. En revanche, les caractéristiques mécaniques de l'assiette (tableau III) sont comparables entre l'essai 1 et l'essai 4, ce qui est normal dans la mesure où le polyester a été fondu, et n'est donc plus dépendant de la forme sous laquelle il a été introduit initialement. Essai n°5 Le PETP est un polyester 6438 de Eastman Kodak, de granulométrie moyenne 200 micromètres. Cet essai confirme le précédent.Comparing with test No. 1 in Table I, we see the very clear advantage of the composition with fibers with regard to drainage. However, the porosity is close, which is surprising. Furthermore, while the density of test No. 1 indicates a Air "content" higher than that of test 4, it can be seen in Table II that the preheating time is nevertheless lower, which is surprising and advantageous. On the other hand, the mechanical characteristics of the base (Table III) are comparable between test 1 and test 4, which is normal insofar as the polyester has been melted, and is therefore no longer dependent on the form in which it was originally introduced. Test # 5 PETP is a 6438 polyester from Eastman Kodak, with an average particle size of 200 micrometers. This test confirms the previous one.
On constate sur le tableau I un egouttage très lent, sur le tableau II un temps de prechauffage très long et sur le tableau III un taux de cendres élevé indiquant une faible rétention du PETP en poudre, qui peut justifier les caractéristiques relativement moins bonnes. Il faut noter enfin le mauvais aspect de l'assiette moulée, lié au temps de préchauffage très long conduisant à des dégradations superficielles du matériau. Essai n°6Table I shows a very slow drainage, in Table II a very long preheating time and in Table III a high ash rate indicating a low retention of the powdered PETP, which can justify the relatively poorer characteristics. Finally, note the bad appearance of the molded plate, linked to the very long preheating time leading to surface degradation of the material. Test # 6
Le PETP est un polyester fourni par ENKA et broyé à une granulométrie inférieure à 300 micromètres.PETP is a polyester supplied by ENKA and ground to a particle size of less than 300 micrometers.
A noter un egouttage lent, un temps de préchauffage supérieur à celui des fibres qui conduit à un brunissement important à la surface de l'assiette moulée.Note a slow draining, a preheating time greater than that of the fibers which leads to significant browning on the surface of the molded plate.
Le taux de cendres est encore assez élevé.The ash rate is still quite high.
L'utilisation de fibres thermoplastiques permet donc par rapport aux poudres une meilleure machinabilité, une plus grande productivité et une transformation grandement facilité. 1.2.1. Compositions sans cellulose (comparatif) Essai nº 7 Fibres de verre R18DX9 6 mm 11 micromètres 23,9 parts PETP Fibres T 900 de Rhone Poulenc 3,3 dtex, 3mm 76,1 parts Une telle composition conduit à un produit impossible à tirer convenablement sur une machine à papier industrielle en partie humide et en partie sèche, par suite du manque de cohésion et du retrait élevé lors du séchage. De plus on a indiqué dans le tableau II un très fort fluage : la matière coule et nécessite de replier l'ensemble en boule ; la matière se refroidit. Le procédé n'est pas industriel. Ce fort fluage s'explique par l'absence de la cellulose qui apportait la cohésion nécessaire au produit préchauffé. Les caractéristiques observées sur le tableau III sont un peu meilleures qu'avec les compositions contenant de la cellulose (voir essai 10), mais pas autant qu'on aurait pu l'espérer, surtout compte tenu du taux de fibres de verre plus élevé. Ceci confirme le caractère non pénalisant de la cellulose. Essai n° 8The use of thermoplastic fibers therefore allows, compared to powders, better machinability, greater productivity and greatly facilitated processing. 1.2.1. Compositions without cellulose (comparative) Test nº 7 Glass fibers R18DX9 6 mm 11 micrometers 23.9 parts PETP Fibers T 900 from Rhone Poulenc 3.3 dtex, 3mm 76.1 parts Such a composition results in a product which cannot be properly drawn on an industrial paper machine which is partly wet and partly dry, due to the lack of cohesion and the high shrinkage during drying. In addition, a very strong creep has been indicated in table II: the material flows and requires the ball to be folded up; the material cools. The process is not industrial. This strong creep is explained by the absence of cellulose which brought the necessary cohesion to the preheated product. The characteristics observed in Table III are slightly better than with the compositions containing cellulose (see test 10), but not as much as could have been hoped for, especially given the higher rate of glass fibers. This confirms the non-penalizing nature of the cellulose. Trial # 8
Pour compenser le manque de cohésion de la feuille en l'absence de cellulose, on reprend l'essai 7 en ajoutant cette fois comme fibres à surface spécifique élevée, une pâte synthétique de polyoléfine. fibres de verre (comme essai 7) 22,4 parts PETP (comme essai 7) 71,2 partsTo compensate for the lack of cohesion of the sheet in the absence of cellulose, test 7 is repeated, this time adding as fibers with a high specific surface, a synthetic polyolefin paste. glass fibers (as in test 7) 22.4 parts PETP (as in test 7) 71.2 parts
Pâte de polyéthylène PULPEX EA commercialisé par HERCULES 6,4 partsPULPEX EA polyethylene paste marketed by HERCULES 6.4 parts
Le tableau II indique qu'on a dû arrêter le préchauffage avant d'atteindre 290°C, en raison d'un très important fluage. Le Pulpex EA utilisé a des fibres de 0,2 à 1,2 mm de long et 10 à 20 micromètres de diamètre.Table II indicates that the preheating had to be stopped before reaching 290 ° C, due to a very large creep. The Pulpex EA used has fibers from 0.2 to 1.2 mm long and 10 to 20 micrometers in diameter.
Essai n°9 Il reprend la composition de l'essai 8 mais dans des conditions de préchauffage différentes pour essayer de pallier au problème rencontré lors de l'essai précédent.Test n ° 9 It uses the composition of test 8 but under different preheating conditions to try to alleviate the problem encountered during the previous test.
Nous avons pu tant bien que mal, malgré le fort fluage qui persiste, mouler une assiette. On constate un aspect final très mauvais, grenu et hétérogène avec des tâches mates dues à l'exsudation de la polyoléfine en surface par suite de son point de fusion trop bas. Les pâtes de polyoléfines ne peuvent donc se substituer à la cellulose dans les applications de l'invention et il est nécessaire d'employer comme fibres de renforcement du produit en fabrication, des fibres dont le point de fusion est supérieur à la température de transformation. 1.2.2. Compositions avec cellulose Essai n°10We were able to somehow, despite the strong creep that persists, mold a plate. There is a very bad, grainy and heterogeneous final appearance with dull spots due to the exudation of the polyolefin at the surface as a result of its too low melting point. Polyolefin pastes cannot therefore be substitute for cellulose in the applications of the invention and it is necessary to use as reinforcing fibers of the product in manufacture, fibers whose melting point is higher than the transformation temperature. 1.2.2. Compositions with cellulose Test n ° 10
Aux fins de comparaison avec l'essai 7, l'essai 10 contient de la cellulose et le même polymère PETP T900 que l'essai 7. La composition est la suivante : Cellulose 10 partsFor comparison with test 7, test 10 contains cellulose and the same PETP T900 polymer as test 7. The composition is as follows: Cellulose 10 parts
Fibres de verre 21,5 partsGlass fibers 21.5 parts
PETP 68,5 partsPETP 68.5 parts
Le polymère T900 légèrement ramifié est un grade de polymère moins bon sur le plan des résistances mécaniques que le T100 linéaire, ce qui explique en grande partie la chute des caractéristiques par rapport à l'essai n°1.The slightly branched T900 polymer is a poorer grade of polymer in terms of mechanical resistance than the linear T100, which largely explains the drop in characteristics compared to test No. 1.
2. COMPOSITIONS CHARGEES2. LOADED COMPOSITIONS
Elles répondent à la formule suivante (parts de poids sec) : Cellulose 14They correspond to the following formula (dry weight shares): Cellulose 14
Fibres de verre 26Glass fibers 26
PETP (fibres ou poudre) 60PETP (fibers or powder) 60
Charge 43Charge 43
2.1. Compositions avec fibres PETP La charge utilisée est un carbonate Millicarb commercialisé par OMYA.2.1. Compositions with PETP fibers The filler used is a Millicarb carbonate marketed by OMYA.
Selon le mode opératoire préférentiel, la charge minérale est introduite dans la cellulose raffinée avant le polyester. Dans ce cas pour assurer une bonne rétention de ladite charge, il est nécessaire d'ajouter en tête de machine un agent de rétention habituel. De bons résultats ont été obtenus avec un polyacrylamide de haut poids moléculaire à raison de 0,2% par rapport aux matières sèches.According to the preferred procedure, the mineral filler is introduced into the refined cellulose before the polyester. In this case to ensure good retention of said load, it is necessary to add a usual retention agent at the top of the machine. Good results have been obtained with a high molecular weight polyacrylamide at a rate of 0.2% relative to the dry matter.
Un tel mélange est ensuite dilué à la concentration souhaitée pour permettre un bon passage sur la machine à papier. Essais n°11 et 12 Les fibres sont un PETP T100 de Rhone Poulenc, 6mm, 17 dtex. L'aspect final des assiettes montre moins de rides que pour une composition non chargée. Essai n° 13Such a mixture is then diluted to the desired concentration to allow good passage through the paper machine. Tests n ° 11 and 12 The fibers are a PETP T100 from Rhone Poulenc, 6mm, 17 dtex. The final appearance of the plates shows fewer wrinkles than for an unfilled composition. Test # 13
Les fibres sont un PETP T100 de Rhone Poulenc, 6mm, 3,3 dtex. Comme à l'essai 11, on constate une diminution des rides des assiettes par rapport aux compositions non chargées. Essai n°14 Les fibres sont un PETP de MONTEFIBRE, de 6mm de longueur.The fibers are a PETP T100 from Rhone Poulenc, 6mm, 3.3 dtex. As in test 11, there is a reduction in wrinkles on the plates compared to the uncharged compositions. Test n ° 14 The fibers are a PETP of MONTEFIBRE, 6mm in length.
La réduction des rides est moins nette qu'avec le PETP de Rhone Poulenc et le taux de cendres en charges indique un problème de rétention de la charge. Essai n°15 Les fibres sont des fibres PETP DACRON de DUPONT DE NEMOURS, D157N, 6mm, 7 dtex.The reduction in wrinkles is less marked than with Rhone Poulenc's PETP and the rate of ash in charges indicates a problem of retention of the charge. Test n ° 15 The fibers are PETP DACRON fibers from DUPONT DE NEMOURS, D157N, 6mm, 7 dtex.
On a constaté à nouveau la réduction des rides par rapport aux compositions non chargées.The reduction in wrinkles was again observed compared to the uncharged compositions.
L'ajout de carbonate améliore donc l'état de surface. 2.2. Essais comparatifs avec poudre PETP Essai n°16 La poudre est un PETP T100 de Rhone Poulenc, de granulométrie inférieure à 300 micromètres.The addition of carbonate therefore improves the surface condition. 2.2. Comparative tests with PETP powder Test n ° 16 The powder is a PEThone T100 from Rhone Poulenc, with a particle size less than 300 micrometers.
Cet essai montre comme avec les fibres, une amélioration de l'aspect par rapport à l'essai 4 mais avec une nette réduction de l'égouttage et une augmentation du temps de préchauffage par rapport à l'essai 11.This test shows, as with the fibers, an improvement in appearance compared to test 4 but with a marked reduction in drainage and an increase in the preheating time compared to test 11.
Essai n°17 La poudre est un PETP 64-38 de Kodak de granulométrie moyenne de 200 micromètres.Test No. 17 The powder is a PETP 64-38 from Kodak with an average particle size of 200 micrometers.
Les rides sont analogues à celles des compositions avec fibres de Rhone Poulenc, mais il y a plus de points mats.Wrinkles are similar to those of Rhone Poulenc fiber compositions, but there are more dots.
Cet essai confirme lui aussi l'intérêt des compositions avec fibres PETP puisqu'ici le temps de prechauffage est réduit du fait de la quantité de matière plus faible. 2.3. Compositions avec d'autres chargesThis test also confirms the advantage of compositions with PETP fibers since here the preheating time is reduced due to the lower quantity of material. 2.3. Compositions with other charges
Compte tenu des essais comparatifs ci-dessus, et selon l'invention, d'autres charges minérales sont testées avec le PETP sous forme de fibres PETP T100 de Rhone Poulenc, 3mm, 17 dtex. Essai n°18Taking into account the above comparative tests, and according to the invention, other mineral fillers are tested with PETP in the form of PETP T100 fibers from Rhone Poulenc, 3mm, 17 dtex. Trial # 18
La charge est du carbonate Millicarb OMYA de granulométrie moyenne 1 à 2 micromètres. Essai n°19 La charge est de carbonate B038 de Blanc Minéraux de Paris, de granulométrie 10 à 12 micromètres.The charge is Millicarb OMYA carbonate with an average particle size of 1 to 2 micrometers. Test No. 19 The charge is carbonate B038 from Blanc Minéraux de Paris, with a particle size of 10 to 12 micrometers.
Dans ces deux derniers essais, on constate la présence de quelques rides sur les assiettes moulées.In these last two tests, we note the presence of some wrinkles on the molded plates.
Essai n°20 La charge est du talc (silicate de magnésium hydraté) N°2 des Talcs de Luzenac, de granulométrie moyenne 12 micromètres.Test No. 20 The charge is talc (hydrated magnesium silicate) No. 2 of Talcs from Luzenac, with an average particle size of 12 micrometers.
L'aspect de surface est encore amélioré par rapport aux compositions avec carbonates. 3. ETUDE DE MOULABILITEThe surface appearance is further improved compared to compositions with carbonates. 3. MOULDABILITY STUDY
Plus on a des pièces compliquées, plus le remplissage du moule peut poser des problèmes. A cet effet, il peut être utile de réduire autant que possible la teneur en matière non thermoplastique. Les fibres de renforcement du produit fini étant indispensables, il est bien entendu préférable de diminuer la teneur des fibres de renfort nécessaires à la fabrication. Ainsi des essais ont été réalisés sur des compositions sans charge minérale, pour situer la teneur minimale des fibres de cellulose à introduire pour permettre une fabrication satisfaisante sur une machine à papier conventionnelle ou lors des manipulations avant moulage, sans nuire à la moulabilité. Pour tous ces essais, nous avons utilisé le polyesterThe more complicated the parts, the more problematic the filling of the mold can be. To this end, it may be useful to reduce the content of non-thermoplastic material as much as possible. Since the reinforcing fibers of the finished product are essential, it is of course preferable to reduce the content of the reinforcing fibers necessary for manufacturing. Thus tests have been carried out on compositions without mineral filler, to locate the minimum content of the cellulose fibers to be introduced to allow satisfactory manufacture on a conventional paper machine or during handling before molding, without adversely affecting the moldability. For all these tests, we used polyester
PETP T100 de Rhone Poulenc en fibres de 6mm et 17 dtex et des fibres de verre R18DX9 commercialisées par OWENS CORNING FIBERGLAS EUROPE de 6mm et 11 micromètres. Essai n°21PETP T100 from Rhone Poulenc in 6mm and 17 dtex fibers and R18DX9 glass fibers marketed by OWENS CORNING FIBERGLAS EUROPE of 6mm and 11 micrometers. Trial # 21
Avec 10 parts de cellulose, soit en parts en poids sec :With 10 parts of cellulose, i.e. in parts by dry weight:
Fibres de cellulose 10Cellulose fibers 10
Fibres de verre 21,5 PETP 68,5Glass fibers 21.5 PETP 68.5
Essai n°22Trial # 22
Avec 5 parts de cellulose :With 5 parts of cellulose:
Fibres de cellulose 5Cellulose fibers 5
Fibres de verre 21 PETP 74Glass fibers 21 PETP 74
Essai n°23 (comparatif)Test No. 23 (comparative)
Avec 2 parts de cellulose :With 2 parts of cellulose:
Fibres de cellulose 2Cellulose fibers 2
Fibres de verre 21 PETP 77Glass fibers 21 PETP 77
En ce qui concerne les conditions de passage sur la machine pilote et de manutention de la feuille sèche, on constate un très net avantage de la composition avec 5 parts de cellulose par rapport à celle avec 2 parts. Cette dernière donne une feuille ayant une très faible cohésion humide et sèche et conduit à un très fort fluage de la matière thermoplastique lors du préchauffage. Ce fluage important et la mauvaise cohésion du matériau fondu rendent impossible toute opération de densification en feuille rigide et/ou toute manipulation de ce matériau pour sa mise en place dans le moule d'estampage. Une telle composition n'est donc pas industrielle.With regard to the conditions of passage on the pilot machine and handling of the dry sheet, there is a very clear advantage of the composition with 5 parts of cellulose compared to that with 2 parts. The latter gives a sheet having a very low wet and dry cohesion and leads to a very high creep of the thermoplastic material during preheating. This significant creep and the poor cohesion of the molten material make any densification operation in rigid sheet and / or any manipulation of this material impossible for its positioning in the stamping mold. Such a composition is therefore not industrial.
La composition avec 5 parts de cellulose permet un passage correct sur machine à papier et possède une tenue suffisante pour permettre la manutention, la découpe de la feuille sèche et le prechauffage sans fluage de matière.The composition with 5 parts of cellulose allows correct passage on a paper machine and has sufficient strength to allow handling, cutting of the dry sheet and preheating without material creep.
Sur ces trois essais, nous avons testé l'aptitude du matériau à remplir un moule lors de l'opération d'estampage. Il s'agit du test bien connu dans la profession des matériaux composites du "moule à oreille". Les valeurs de moulabilité regroupées dans le tableau III représentent la distance en grades parcourue par la matière suivant une orientation circulaire. Le schéma en annexe montre l'assiette 1 dont un bord 2 peut lors du moulage s'étirer circonférentiellement en oreille 3 dont l'extension est mesurée par une graduation 4 du moule.On these three tests, we tested the ability of the material to fill a mold during the stamping operation. This is the well-known test in the profession of "ear mold" composite materials. The moldability values grouped in the table III represent the distance in grades traveled by the material in a circular orientation. The diagram in annex shows the plate 1, one edge 2 of which can, during molding, stretch circumferentially in ear 3, the extension of which is measured by a graduation 4 of the mold.
On ne constate aucun écart de moulabilité entre 2 et 5 parts de cellulose ce qui est surprenant.There is no difference in moldability between 2 and 5 parts of cellulose, which is surprising.
Cependant, comme on l'a dit, des compositions où la teneur en cellulose n'atteint pas 3 parts en poids n'ont généralement pas une résistance à la manipulation convenable pendant le préchauffage qui précède le pressage à chaud.However, as has been said, compositions in which the cellulose content does not reach 3 parts by weight generally do not have suitable resistance to handling during the preheating which precedes the hot pressing.
Ces résultats justifient notre limite inférieure du taux de cellulose dans la fourchette des compositions données.These results justify our lower limit of the rate of cellulose in the range of the given compositions.
Pour ce qui est de la limite supérieure du taux de cellulose, elle est fixée par la valeur qui conduit à une capacité d'absorption d'eau généralement inacceptable dans le produit final, c'est-à-dire environ 15 parts en poids. C'est aussi à cette valeur que les compositions deviennent moins facilement moulables, surtout pour des pièces de forme compliquées. As for the upper limit of the cellulose content, it is fixed by the value which leads to a generally unacceptable water absorption capacity in the final product, that is to say about 15 parts by weight. It is also at this value that the compositions become less easily moldable, especially for complicated shaped parts.
Figure imgf000021_0001
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Figure imgf000023_0001
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Claims

REVENDICATIONS
1. Composition de feuille fibreuse fabriquée par voie humide, adaptée pour être moulée en un produit thermoplastique renforcé, comprenant des fibres de renforcement de la composition pendant la fabrication, des fibres de renforcement du produit moulé, et une résine thermoplastique, caractérisée en ce que ladite composition comprend, en parts en poids sec (basées sur 100 parts des premier , deuxième et troisième constituants combinés) : a) de 3 à 15 parts d'un premier constituant consistant en fibres de renforcement de la composition pendant sa fabrication b) une quantité de renforcement d'un second constituant fibreux efficace pour renforcer le produit thermoplastique formé par moulage à chaud de la composition fibreuse, et c) le reste en parts d'un troisième constituant consistant en fibres de polyester thermoplastique, le premier constituant ayant une température de fusion ou de dégradation supérieure à celle de fusion du troisième constituant.1. Composition of fibrous sheet manufactured by the wet method, suitable for being molded into a reinforced thermoplastic product, comprising fibers for reinforcing the composition during manufacture, fibers for reinforcing the molded product, and a thermoplastic resin, characterized in that said composition comprises, in parts by dry weight (based on 100 parts of the first, second and third constituents combined): a) from 3 to 15 parts of a first constituent consisting of fibers for reinforcing the composition during its manufacture b) a amount of reinforcement of a second fibrous component effective for reinforcing the thermoplastic product formed by hot molding of the fibrous composition, and c) the remainder in parts of a third component consisting of thermoplastic polyester fibers, the first component having a temperature of fusion or degradation greater than that of fusion of the third constituent.
2. Composition selon la revendication 1, caractérisée en ce qu'elle comprend de 4 à 8 parts, de préférence de 4,5 à 6 parts en poids du premier constituant.2. Composition according to claim 1, characterized in that it comprises from 4 to 8 parts, preferably from 4.5 to 6 parts by weight of the first constituent.
3. Composition selon l'une quelconque des revendications 1 ou 2, caractérisée en ce que le premier constituant comprend de la cellulose. 3. Composition according to any one of claims 1 or 2, characterized in that the first constituent comprises cellulose.
4. Composition selon l'une quelconque des revendications précédentes, caractérisée en ce qu'elle comprend de 15 à 40 parts en poids du deuxième constituant.4. Composition according to any one of the preceding claims, characterized in that it comprises from 15 to 40 parts by weight of the second constituent.
5. Composition selon la revendication 4, caractérisée en ce qu'elle comprend de 18 à 27, de préférence de 21 à 26 parts en poids du deuxième constituant.5. Composition according to claim 4, characterized in that it comprises from 18 to 27, preferably from 21 to 26 parts by weight of the second constituent.
6. Composition selon l'une quelconque des revendications précédentes, caractérisée en ce que le deuxième constituant comprend des fibres de verre.6. Composition according to any one of the preceding claims, characterized in that the second constituent comprises glass fibers.
7. Composition selon la revendication 6, caractérisée en ce que les fibres de verre ont une longueur de 6 à 50 mm, de préférence 6 à 25 mm.7. Composition according to claim 6, characterized in that the glass fibers have a length of 6 to 50 mm, of preferably 6 to 25 mm.
8. Composition selon l'une quelconque des revendications précédentes, caractérisée en ce qu'elle comprend de 45 à 85 parts en poids du troisième constituant. 8. Composition according to any one of the preceding claims, characterized in that it comprises from 45 to 85 parts by weight of the third constituent.
9. Composition selon la revendication 8, caractérisée en ce qu'elle comprend de 58 à 79, de préférence de 65 à 75 parts en poids du troisième constituant.9. Composition according to claim 8, characterized in that it comprises from 58 to 79, preferably from 65 to 75 parts by weight of the third constituent.
10. Composition selon l'une quelconque des revendications précédentes, caractérisée en ce que le troisième constituant comprend un polyéthylène téréphtalate.10. Composition according to any one of the preceding claims, characterized in that the third constituent comprises a polyethylene terephthalate.
11. Composition selon la revendication 1, caractérisée en ce qu'elle comprend de 3 à 15 parts du premier constituant, de 18 à 27 parts du second constituant et de 58 à 79 parts du troisième constitutant. 11. Composition according to claim 1, characterized in that it comprises from 3 to 15 parts of the first constituent, from 18 to 27 parts of the second constituent and from 58 to 79 parts of the third constituent.
12. Composition selon l'une quelconque des revendications précédentes, caractérisée en ce que la température de fusion ou de dégradation du premier composant est supérieure d'au moins 50°C, de préférence 65°C, à la température de fusion du troisième composant.12. Composition according to any one of the preceding claims, characterized in that the melting or degradation temperature of the first component is at least 50 ° C, preferably 65 ° C, above the melting temperature of the third component .
13. Composition selon l'une quelconque des revendications précédentes, caractérisée en ce qu'elle comprend en outre des charges.13. Composition according to any one of the preceding claims, characterized in that it also comprises fillers.
14. Composition selon la revendication 13, caractérisée en ce qu'elle contient de 20 à 45 parts en poids sec de charges, basées sur 100 parts en poids sec des premier, deuxième et troisième constituants combinés.14. Composition according to claim 13, characterized in that it contains from 20 to 45 parts by dry weight of fillers, based on 100 parts by dry weight of the first, second and third constituents combined.
15. Produit thermoplastique renforcé comprenant une composition fibreuse selon l'une quelconque des revendications précédentes, caractérisé en ce qu'il a été soumis à une température au moins égale à la température de fusion du troisième constituant pendant un temps suffisant pour faire fondre ce troisième constituant, puis refroidi sous application de pression.15. Reinforced thermoplastic product comprising a fibrous composition according to any one of the preceding claims, characterized in that it has been subjected to a temperature at least equal to the melting temperature of the third constituent for a time sufficient to melt this third constituent, then cooled under pressure.
16. Produit selon la revendication 15, caractérisé en ce qu'il possède un revêtement de surface de type vernis, de préférence thermodur. 16. Product according to claim 15, characterized in that it has a varnish-type surface coating, preferably thermoset.
17. Procédé de fabrication d'un produit selon la revendication 15, caractérisé en ce qu'il comprend :17. Method of manufacturing a product according to the claim 15, characterized in that it comprises:
1) le préchauffage de la feuille fibreuse selon l'une quelconque des revendications 1 à 14 à une température inférieure à la température de fusion ou de dégradation du premier constituant, mais supérieure à la température de fusion du troisième constituant de manière à faire fondre le troisième constituant mais à conserver l'effet de renforcement du premier constituant, et,1) the preheating of the fibrous sheet according to any one of claims 1 to 14 to a temperature below the melting or degradation temperature of the first constituent, but above the melting temperature of the third constituent so as to melt the third constituent but to retain the reinforcing effect of the first constituent, and,
2) le moulage de la feuille chauffée sous pression et à température inférieure à la température de fusion du troisième constituant de manière à former le produit moulé désiré.2) molding the heated sheet under pressure and at a temperature below the melting temperature of the third constituent so as to form the desired molded product.
18. Procédé selon la revendication 17, caractérisé en ce que la feuille est préchauffée à une température supérieure d'au moins 30°C à la température de fusion du troisième constituant.18. The method of claim 17, characterized in that the sheet is preheated to a temperature at least 30 ° C higher than the melting temperature of the third constituent.
19. Article moulé fabriqué à partir du produit selon l'une quelconque des revendications 15 ou 16 ou du procédé selon l'une quelconque des revendications 17 ou 18. 19. A molded article made from the product according to any one of claims 15 or 16 or the method according to any one of claims 17 or 18.
PCT/FR1988/000404 1987-08-04 1988-08-04 Compositions for thermoplastic sheet manufactured by a wet process WO1989001075A1 (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
BR888807638A BR8807638A (en) 1987-08-04 1988-08-04 COMPOSITION FOR THERMOPLASTIC SHEET MANUFACTURED BY HUMID WAY, REINFORCED THERMOPLASTIC PRODUCT, MANUFACTURING PROCESS AND MOLDED ARTICLE MADE
KR1019890700589A KR890701843A (en) 1987-08-04 1988-08-04 Wet-Batch Thermoplastic Web Compositions, Reinforced Thermoplastic Articles Comprising the Same, and Methods for Making the Same

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR87/11067 1987-08-04
FR8711067A FR2619117A1 (en) 1987-08-04 1987-08-04 PAPER COMPOSITION, PARTICULARLY FOR REINFORCED REINFORCED THERMOPLASTIC SHEET

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JP (1) JPH03501276A (en)
KR (1) KR890701843A (en)
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BR (1) BR8807638A (en)
FR (1) FR2619117A1 (en)
WO (1) WO1989001075A1 (en)

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EP0341977A2 (en) * 1988-05-10 1989-11-15 E.I. Du Pont De Nemours And Company Composites from wet formed blends of glass and thermoplastic fibers

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Publication number Priority date Publication date Assignee Title
GB0315042D0 (en) * 2003-06-27 2003-07-30 Excel Ind Ltd Composite material

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GB572962A (en) * 1942-05-25 1945-10-31 Sylvania Ind Corp Paper products and methods of making the same
GB1200342A (en) * 1967-06-02 1970-07-29 Ici Ltd Reinforcing thermoplastic materials
FR2346520A1 (en) * 1976-03-30 1977-10-28 Ici Ltd SHEET-TYPE WALL OR CEILING COVERINGS
GB2070092A (en) * 1978-08-21 1981-09-03 Grace W R & Co Process for producing a web useful as a battery separator
EP0039292A1 (en) * 1980-04-30 1981-11-04 Arjomari-Prioux S.A. Sheet material which can be converted into a finished product by moulding, embossing or thermoforming, comprising reinforcing fibres and a powdery thermoplastic resin, and process for preparing said material
FR2507123A1 (en) * 1981-06-04 1982-12-10 Arjomari Prioux Reinforced thermoplastic semi-finished sheet prod. - prepd. from poly-aramid pulp, thermoplastic powder or fibres and opt. binder, for thermo-forming or stamping
EP0113279A1 (en) * 1982-12-30 1984-07-11 Société Chimique des Charbonnages Layered products having a topcoat
EP0151448A1 (en) * 1984-01-27 1985-08-14 Kureha Chemical Industry Co., Ltd. Process for producing electroconductive films
WO1987004476A1 (en) * 1986-01-17 1987-07-30 Battelle Memorial Institute Wet-laid, non-woven, fiber-reinforced composites containing stabilizing pulp

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GB572962A (en) * 1942-05-25 1945-10-31 Sylvania Ind Corp Paper products and methods of making the same
GB1200342A (en) * 1967-06-02 1970-07-29 Ici Ltd Reinforcing thermoplastic materials
FR2346520A1 (en) * 1976-03-30 1977-10-28 Ici Ltd SHEET-TYPE WALL OR CEILING COVERINGS
GB2070092A (en) * 1978-08-21 1981-09-03 Grace W R & Co Process for producing a web useful as a battery separator
EP0039292A1 (en) * 1980-04-30 1981-11-04 Arjomari-Prioux S.A. Sheet material which can be converted into a finished product by moulding, embossing or thermoforming, comprising reinforcing fibres and a powdery thermoplastic resin, and process for preparing said material
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EP0113279A1 (en) * 1982-12-30 1984-07-11 Société Chimique des Charbonnages Layered products having a topcoat
EP0151448A1 (en) * 1984-01-27 1985-08-14 Kureha Chemical Industry Co., Ltd. Process for producing electroconductive films
WO1987004476A1 (en) * 1986-01-17 1987-07-30 Battelle Memorial Institute Wet-laid, non-woven, fiber-reinforced composites containing stabilizing pulp

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0341977A2 (en) * 1988-05-10 1989-11-15 E.I. Du Pont De Nemours And Company Composites from wet formed blends of glass and thermoplastic fibers
EP0341977A3 (en) * 1988-05-10 1991-10-09 E.I. Du Pont De Nemours And Company Composites from wet formed blends of glass and thermoplastic fibers

Also Published As

Publication number Publication date
KR890701843A (en) 1989-12-21
AU2260988A (en) 1989-03-01
FR2619117A1 (en) 1989-02-10
BR8807638A (en) 1990-08-07
JPH03501276A (en) 1991-03-22
EP0304368A1 (en) 1989-02-22

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