Thermoplastic moulding, method of making same and application thereof
Abstract
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6 claims: 3 independent, 3 dependent
- 1Zastrzeżenia patentowe 1. Sposób wytwarzania spienionej wypraski termoplastycznej, obejmujący następujące etapy:dyspergowanie włókien wzmacniających, w stopionej poliolefmie lub w polimerze polikondensacyjnym, wtryskiwanie, otrzymanej w ten sposób kompozycji polimerowej, do zamkniętej formy za pomocą wtryskarki, przy czym kompozycję polimerową wtryskuje się do formy przez dyszę, a forma ta jest częściowo otwierana, wtedy, gdy co najmniej część powierzchni wypraski jest już ochłodzona do temperatury poniżej temperatury mięknienia poliolefiny lub polimeru polikondensacyjnego, a środek wypraski ma temperaturę wyższą niż wyżej wymieniona temperatura mięknienia, zaś 1 do 60% wag. kompozycji polimerowej składa się z włókien wzmacniających o przeciętnej długości między 0,8 a 15 mm, znamienny tym, że kompozycję polimerową zawierającą umiej niż 5000 ppm wilgoci, wtryskuje się do wypraski bez chemicznego środka spieniającego, a formę częściowo otwiera się z szybkością od 0,05 do 10 mm/sek.
- 2Sposób według zastrz. 1, znamienny tym, że stosuje się zbieżną dyszę.
- 3Sposób według zastrz. 1, albo 2, znamienny tym, że stosuje się formę w kształcie talerza.
- 4Sposób według zastrz. 1, znamienny tym, że stosuje się stop poliolefiny o wskaźniku płynięcia stopu wyższym od 30 g/min lub Mn polimeru polikondensacyjnego wyższym od 5000 g/mol.
- 5Spieniona wypraska termoplastyczna wytworzona z kompozycji zawierającej co najmniej poliolefinę lub polimer polikondensacyjny i włókna wzmacniające, gdzie wypraska posiada porowaty środek i co najmniej jedną nieporowatą powierzchnię talerza, zaś 1 do 60% wagowych kompozycji polimerowej składa się ze wzmacniających włókien o długości od 0,8 do 15 mm i gdzie co najmniej ich część znajduje się częściowo w środku, a częściowo w nieporowatej części powierzchni talerza, zaś porowatość wypraski wynosi od 5 do 95% objętościowych, znamienna tym, że wypraska posiada właściwy moduł zginania o wartości co najmniej 10.
- 6Spieniona wypraska termoplastyczna wytworzona z kompozycji zawierającej co najmniej poliolefinę lub polimer polikondensacyjny i włókna wzmacniające, gdzie wypraska posiada porowaty środek i co najmniej jedną nieporowatą powierzchnię talerza, zaś 1 do 60% wagowych kompozycji polimerowej składa się ze wzmacniających włókien o długości od 0,8 do 15 mm i gdzie co najmniej ich część znajduje się częściowo w środku, a częściowo w nieporowatej części powierzchni talerza, zaś porowatość wypraski wynosi od 5 do 95% objętościowych, znamienna tym, że wypraska posiada wytrzymałość właściwą o wartości co najmniej 3,5.
Independent claims6
138 paragraphs, as filed
The subject of the invention is a thermoplastic compact and a method for producing a thermoplastic compact.
JP-A-5-17631 is known for forming a flat plate by injection of fiber-reinforced polypropylene. This method includes the following steps:
a.) dispersing the reinforcing fibers in the molten polyolefin or in a condensation polymer,
b) injecting the composition thus obtained into a closed mold by means of an extruder or an injection molding machine.
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The disadvantage of the method described in JP-A-5-17631 is that the fiber-reinforced polypropylene described therein has a lower specific module and lower specific strength.
From WO-A-94/11177 it is known to use a tapered nozzle, a tapered nozzle is used there to obtain orientation of the plastic and / or fibrous reinforcement in the compact, so that it can have better rigidity and strength in a certain direction. WO-A-W11177 does not mention anywhere that the converging nozzle can cause foaming of the compact.
The resin-reinforced thermoplastic foam compact and the method of producing it is also described in JP07016933. This publication mentions a resin containing 20-70% reinforcing fibers 5-26 mm long. The compact is a foamed body covered on both sides with a layer of leather, where the fibers are located almost parallel to the surface. The core fibers are arranged so that they are almost perpendicular to the surface layer. The compact is obtained with the help of a foaming agent added to the thermoplastic resin. A number of foaming agents are mentioned, among them azodicarbonamide, azobisisobutyronitrile N, N'-dinitropentamethylenetetramine, trihydrazinitriazine and p-toluenesulfonylhydrazine. The foaming agent disintegrates to form gas. JP07016933 discloses the production of a high strength compact in thickness.
The use of a tapered nozzle is mentioned in WO 96/13368 disclosing an injection molding machine equipped with the tapered nozzle and internal lubricating elements. The converging nozzle creates a large orientation of the compact, thanks to which internal lubrication reduces the pressure filling the molds and gives more favorable orientation of the compacts. High orientation results in highly focused structures with considerable strength and modulus. The low weight of the compact is due to the use of a foaming agent. High orientation and high mechanical properties combined with low weight are considered a prerequisite when using thermoplastic moldings as wood substitutes, e.g. in the production of baseball bats.
One example discloses a polypropylene composition with wood fibers, foamed using Uniroyal Celogen AZNP130 as a foaming agent. It has been shown that without the use of a converging nozzle and lubricating elements, low orientation and low mechanical values are obtained, too low for use as wood substitutes.
The compacts described in JP-A-5-17631 containing a polyolefin with a melt flow index of one hundred g / 10 min solder) are known for more than 20% by weight of refractory fibers with a length of 5 mm or more.
The disadvantage of the moldings described in JP-A-5 ^ 17 ^ i31 is that they have a specific modulus and specific strength too low for the fiber reinforced sololefins used.
In known sandwich structures, the poor adhesion between the center and the surface of the plate is often improved by using so-called 3D fabric (three-dimensional fabric), which means the three-dimensional structure of the fabric fiber. A feature of the 3D fabric is that some of the fibers that strengthen the center go to the surface of the plate, which improves the adhesion between the center and the surface. plate. Fabrics and 3D composites are described by A. Śchrauwers in Kunststoff Magazine, 1993, page 16. The disadvantages of 3D fabric are that they should be made to measure in advance and that they must be placed in a mold separately for each injection. In addition, 3D fabric can only be used in combination with thermoset plastics with very low viscosity.
The object of the present invention is to remove the disadvantages of the prior art.
A method for producing a foamed thermoplastic molding, comprising the following steps: dispersing the reinforcing fibers, in a molten polyolefin or in a polycondensation polymer, extrusion or injection of the polymer composition thus obtained, into a closed mold by means of an extruder or injection molding machine, the polymer composition being injected into the mold through a nozzle and the mold being partially opened, then, when at least a part of the compact surface is already cooled to a temperature below the softening point of the sol-olefin or polyol condensation polymer and the compact
185 405 has a higher temperature than the above-mentioned softening point, and 1 to 60 wt. the polymer composition consists of reinforcing fibers has an average length between 0.8 and 15 mm, according to the invention, the polymer composition containing less than 5000 ppm moisture is injected into the compact without the chemical agent foaming the ego, and the mold partially opens with speed from 0.05 to 10 mm / sec.
Preferably, a converging nozzle is used in the method of the invention, and more preferably, in this case a plate-shaped mold is used.
The process of the invention preferably uses a polyolefin melt having a melt index higher than 30 g / min or Mn polycondensation polymer higher than 5000 g / mol.
A foamed thermoplastic compact made of a composition comprising at least a polyolefin or polycondensation polymer and reinforcing fibers, where the compact has a porous center and at least one non-porous plate surface, and 1 to 60% by weight of the polymer composition and consists of reinforcing fibers with a length of 0.8 up to 15 mm and where at least part of them is partly in the center and partly in the non-porous part of the plate surface, and the porosity of the compact is from 5 to 95% by volume, according to the invention it is characterized in that it has a proper bending modulus of at least 10.
In contrast, a foamed thermoplastic compact made of a composition comprising at least a polyolefin or polycondensation polymer and reinforcing fibers, where the compact has a porous center and at least one non-porous plate surface, and 1 to 60% by weight of the polymer composition consists of reinforcing fibers with a length of 0.8 up to 15 mm and where at least part of them is partly in the center and partly in the non-porous part of the plate surface, and the porosity of the compact is from 5 to 95% by volume, according to another embodiment of the invention it is characterized in that it has a specific strength of at least 3.5.
The molding during opening of the mold unexpectedly foams and a thermoplastic molding with a porous center is obtained. The expanded compact obtained by the process of the invention has a better specific modulus and specific strength than known compacts.
Partial opening in the present description means opening the mold in a certain path until the distance between the two mold halves is equal to the desired thickness of the compact.
For a compact, the requirements for rigidity and strength determine the thickness of the compact, and therefore also its price. The so-called specific modulus and specific strength are used to allow comparison of modulus and strength of molded materials. These are indicators measuring, respectively, the molding resistance to deformation and breaking under the action of a bending load per density unit. Specific modulus and specific strength are used especially to compare the modulus and strength of materials of different densities to find the lightest material with the highest rigidity and strength for a given shape. A detailed description of these indicators is given in the book 'Materials Selector: guidelines for the minimum weight design', Champan & Hall, London.
The method of the present invention uses a tapered nozzle because this results in better foaming of the compact when opening the mold, whereas the inventive method does not cause any or almost any anisotropy of the compact.
A converging nozzle can be obtained by means of a conical nozzle tip, but also for example by placing a breaking plate (plates with a series of holes) in front of the nozzle.
The advantages of the present invention are clearly apparent if the method of the present invention is used to form plate-shaped moldings.
The compact according to the invention has two platter surfaces, where in the present description this means two common almost parallel surfaces opposite each other whose length and width are greater than the thickness of the compact between these surfaces. The surface of the plate need not be flat and can be curved or double curved, for example.
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Partial opening of the mold when at least part of the compact surface has cooled to a temperature below the softening point of the polyolefin or polycondensation polymer results in a compact with at least one non-porous plate surface, i.e. with at least one non-porous surface. The presence of at least one non-porous plate surface improves the specific modulus and specific strength compared to a non-foamed compact. Such a surface can also be painted accordingly.
The mold partly opens preferably only when both plate surfaces have cooled down.
As a result, both plate surfaces are non-porous and a compact molding structure is obtained. The prefabricated structure gives the plate-shaped compact an additional high rigidity and strength.
In the method according to the invention, at least part of the reinforcing fibers is present partly in the middle and partly on the non-porous surface of the plate, as a result of which it is not necessary to use 3D fabric. It was also found that the fibers in the center of the compact form a three-dimensional network and lie parallel to the surface of the compact. The method according to the invention for the first time allows the use of the injection technique to produce (half) a fiber reinforced sandwich structure of fiber reinforced thermoplastic in which the fibers from the center extend to the surface. This structure contributes to the perfect specific module and specific strength, even when only one surface of the plate is non-porous.
In this specification, the melt flow index (MFI) is the melt flow index, measured according to ISO 1133. For polypropylene, the melt flow index is measured at a temperature of 230 ° C and a load of 2.16 kg.
The melt flow index of the polyolefin melt used in the process of the invention is preferably above 30 g / 10 min, more preferably above 50 g / 10 min. It has been found that this melt flow index improves molding foaming when the mold is opened. Preferably, the melt flow index is below 700 g / 10 min.
The number average molecular weight (M<sub>n</sub>preferably) the polycondensation polymers used in the process according to the invention have a value above 5000 g / mol. The method is useful for all currently available polycondensation polymers. With current polymerization technologies, a value of about 90,000 g / mol is the upper limit of the molecular weight of available polycondensation polymers. It is believed that higher molecular weight polycondensation polymers, when they become available, can be processed by the process of the invention to a molecular weight of about 200,000 g / mol.
In this specification, the "average fiber length" is the number average fiber length. It can be determined in the compact by measuring the length of the fibers by means of an optical microscope after removal of the polymer matrix, for example by burning the polymer.
If the polymer composition contains glass fibers as reinforcing fibers, the polymer composition preferably contains from 5 to 60% by weight, more preferably from 10 to 60% by weight of glass fibers. If the polymer composition contains carbon fibers as reinforcing fibers, the polymer composition preferably contains from 1 to 10 by weight, more preferably from 2 to 7% by weight of carbon fibers.
Such mixtures have been found to foam very well.
It was found that the compact can easily foam to 20 times its initial thickness. It gives a compact with a porosity of 95%. The porosity (P) of the compact here and hereinafter is defined by the formula:
P - [d (0) - d (p)] / d (0) * 100,% where d (0) means density before foaming and d (p) means density after foaming. An advantage of the process according to the invention is also that a porous compact can be obtained without the need for a chemical or physical foaming agent. High porosity of the compact is advantageous due to obtaining a high specific modulus and specific strength, because these indicators are inversely proportional to the density.
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The compact's resistance to bending under the action of force is expressed by means of a specific module and tear resistance by means of specific strength. These quantities actually depend on the shape of the object. The specific module and specific strength of the compact plate are best approximated by these flat plate properties.
The specific module of a flat plate is the quotient of the cubic root of the bending module by the density, with the numerical index being obtained when the bending module is expressed in MPa and the density in kg / m<sup>3</sup>. The specific strength of the plate is the quotient of the square root of bending stress by density, the numerical index being obtained when the bending stress is expressed in MPa and the density in kg / m3. A description of these indicators is also provided in the book 'Materials Selector: guidelines for the minimum weight design', Champan and Hall, London.
The mold opening speed is preferably selected depending on the viscosity of the polyolefin or on M<sub>n</sub> polycondensation polymers. If the viscosity to Mn ratio is high, a lower velocity is preferably chosen than if the viscosity to Mn ratio is low. The best results are obtained by choosing this speed to the molding foaming speed in such a way that after opening the mold, the molding is still pressed against the mold halves as a result of foaming the molding, and that both plate surfaces accurately reproduce the mold surfaces in contact with them.
The mold is preferably opened at a speed of from 0.05 to 10 min / s, because it allows obtaining a high porosity compact with a pore-free surface.
It has been found that these limits may vary depending on the amount of moisture in the dispersion. The more moisture is present in the dispersion, the faster or farther the mold can be opened, with at least one smooth plate surface and no pores. A skilled person can easily determine the opening speed and the distance to open the mold. The amount of moisture in the dispersion is preferably below 5000 ppm. Then the signs of a hollow on the surface are avoided.
The invention also relates to a plate-shaped thermoplastic compact containing at least a polyolefin or polycondensation polymer and reinforcing fibers.
The object of the present invention is to obtain a compact without this disadvantage.
This object is achieved in that the compact has a porous center and at least one non-porous plate surface, and at least 1 to 60% by weight of the compact consists of reinforcing fibers with an average length of 0.8 to 15 mm, of which at least a part is partly in the center and partly in the non-porous part of the plate, and the compact has a porosity of 5 to 95% by volume, preferably 10 to 90% by volume and more preferably 20 to 85% by volume. The foamed molding according to the invention has a higher specific rigidity and specific strength than non-foamed moldings which are described, for example, in JA-A-5-17 631.
For moldings with a porosity above 20% by weight, the anisotropy proved to be very small, while moldings with a porosity below 95% by volume have a non-porous plate surface.
The polyolefin preferably has a melt flow index of at least 30 g / 10 min.
The polyolefin can be selected from the group consisting of polyethylene and polypropylene or copolymers of ethylene and propylene. Preferably, the polyolefin contains polypropylene. The advantage of polypropylene is the high melting point, the compact also has a higher deflection temperature and a relatively low price.
Suitable polycondensation polymers are the following polymers: polycarbonate, polyester, polyamide, polyarylate, polyketone, polyimide, polyaramide, liquid crystal polymer (LCP), polyurethane and copolymers of such polycondensates. Polycondensation polymers are preferably selected from the group consisting of polyamide 6, polyamide 6.6, polyamide 11, polyamide 12, poly (ethylene terephthalate), poly (butylene terephthalate) or copolymers thereof. The advantage of the latter group is its relatively low price.
The reinforcing fibers can be selected from the group consisting of carbon fibers, aramid fibers, metal fibers, glass fibers, ceramic fibers or mixtures thereof. The compact according to the invention preferably contains glass fiber as reinforcing fibers
185 405 or carbon fibers. The advantage of glass fibers is their low price. The advantage of carbon fibers is their high tensile strength.
Although the advantages of the invention are already obtained when at least one plate surface is non-porous, preferably both plate surfaces are non-porous. Then the compact has a sandwich structure. The advantage of a sandwich structure is that the material's specific properties are better than those of a compact that does not have this sandwich structure. As a result of this sandwich structure and the fact that part of the reinforcing fibers are present partly in the middle and partly in the non-porous surface of the plate, the compact according to the invention preferably has a bending specific module of at least 10.
The compacts according to the invention are preferably used in building panels, body panels and panels in the automotive industry, white products for the construction industry, splash guards, noise shields, fire walls, luggage racks, fenders, engine covers, dashboards, washing machines, dryers drum, trailers and airplanes, bumper beams, car doors, loading platforms, helmets, armor plates, both in thermal as well as in acoustic insulating walls, in containers, pallets, acoustic partitions, roof coverings, transport containers and switchboards.
The compacts of the invention can also be used in bicycle, scooter and motorcycle parts. Especially for applications where sound insulation is important, the compacts of the invention are very advantageous. Particularly, the use of the compact according to the invention is advantageous in products that should meet soundproofing requirements. It has been found that the differences in density between the non-porous plate surface and the interior of the molded parts of the invention have a positive effect on their soundproofing properties.
The invention is further elucidated with reference to the following examples.
Reinforcing fibers can be dispersed in the molten polyolefin or in the condensation polymer by using as a starting material chopped filament threads which have been pultruffed or coated with a given thermoplastic material.
During pultrusion, the filament bundle is separated into individual fibers and drawn through an impregnation die into which molten thermoplastic material is injected. After fiber separation, each filament is completely wetted and saturated with molten thermoplastic. A smooth strand with a diameter of about 3 mm is drawn from the die and then cooled. Finally, the bundle is cut into granules of the desired length (for example, 10 to 12 mm long). The fibers are usually parallel to each other in granules, each fiber being surrounded separately by a thermoplastic material. Pultruded fibers are produced, for example, by Hoechst / PCI (Compec®, Cestran®), Borealis (Nepol®), LNP / Kawasaki Steel (Verton®).
The coating of continuous reinforcing fibers with a thermoplastic material in which the individual fibers are not wettable is referred to in this description as Continuous Glass Sheathing (CGS). The advantage over pultrusion is a higher production speed (and therefore lower costs). Also for CGS granules, the length of the fiberglass is the same as the length of the granules and the fibers are parallel to each other. Pultruded and coated fibers are easily dispersed in the molten thermoplastic material in the melting zone of the extruder.
The melt flow index was measured according to ISO 1133, for polypropylene at 230 ° C and under a load of 2.16 kg.
The flexural modulus and flexural strength were determined according to ISO 178, with a l / d ratio of 16.
In the tests, the Stork SX-3000-2100 injection molding machine was used. The screw used was a universal screw with a diameter of 72 mm, length 22D (supply / compression / pump: 12D / 6D / 4D). The thread depth in the supply zone was 9.75 mm and in the pump zone 5 mm. The compression ratio was 1.95.
The screw tip is a standard PVC screw tip connected in series with a ring valve. The tip of the head is a standard tip
185 405 head with a length of 117 mm and an internal diameter of 19 mm, which converges over a length of 10 mm to a final diameter of 4 mm.
The material was injected into the mold on a flat plate (510 x 310 mm) through the middle ingot.
The following examples show the production of a compact from a polymer composition comprising a polyolefin or polycondensate and reinforcing fibers, which compact swells without the use of a chemical foaming agent. The polymer composition contains less than 5000 ppm moisture, and the obtained compact has the proper bending module E<sub>sPC</sub>.<sub>:</sub> with a value of at least 10 and an Ospec specific strength of at least 3.5. The comparative examples show a process whose product is swollen compacts or compacts with cavity marks when the moisture content of the polymer is over 5000 ppm.
Example I.
A compact was produced using as a material a mixture consisting of PP-coated glass fiber rovings. Fiber glass roving was mixed with PP fibers. Fiberglass mixture<sup>e</sup>PP was obtained from Vetrotex (Twintex, R PP75 630-02); MFI (230<sup>e</sup>C, 2.16 mg) PP fiber was 20 g / 10 min. PP coating was obtained from DSM (Stamylan PI 12MN40). MIFI (230 ° C, 2.16 mg) of the PP coating was 47 g / 10 min. The fiberglass content of the mixture was 37.5% by weight, the weight ratio was PP<sub>TO ME</sub>.and<sub>0)</sub> to PP<sub>TO ME</sub> ..<sub>1(0</sub> was 4: 1. Thus, MFH PP in the mixture was 40 g / 10 m in. Long<sup>in</sup> granules are U 12 mm.
The injection molding machine from Stork described above was used as the injection molding machine, with the following settings: cylinder temperature - loading hopper / zone 1 / zone 2 / zone 3 / zone 4 / zone 5 / head are bun. nor 40/2<sup>from</sup>0 / 290/300/320/320/320 ° Q temperatuea for / my 110 ° C; 20 revolutions per minute; dosing path 180 mm; back pressure of 3 bar; pressing pressure - no; cooling time from 105 to 150 s, depending on the thickness of the product; injection speed 83 mm / s; dispensing time 35 s; loading rate 100%.
The material was dispersed in an injection molding machine and injected into a mold on a plate, which was 4 mm thick, through a converging nozzle. Immediately after injection, the mold was opened at a linear speed of 0.08 mm / s over a 3.1 mm path. After the cooling time, during which the entire compact has cooled down to a temperature below the softening point of PP, the mold was opened further and the compact was pushed out.
It was found that the compacted foam evenly and had a thickness of 7.1 mm, density 602 kg / m<sup>3</sup> and a 51% comparison. The bending module (E) was 2325 MPa, \ bending strength o / y2 was 44.3 MMPa<sup>1</sup> elongation at break (e, ^) was 3.33%. Property module (E<sub>spe</sub>.) was 10.2 and specific strength (a<sub>spec</sub>) was 3.5. The surface did not contain pores and was smooth on one<sup>m</sup> side and was porous and smooth on the other frost. This indicates that at MFI = 40 g / 10 min, the foaming occurs so slowly that at the selected opening speed only one surface of the molding has sufficient contact with the mold to form a non-porous tsler2a.
Example<sup>-</sup>.
A compact was produced using as a material a mixture consisting of PP-coated glass fiber rovings. Roving fiberglass was mixed with the fibers. Fiberglass mixture<sup>about</sup> PP received from the final Ve<sup>s</sup>rotex (To'i2tex, R PP7<sup>0</sup> 630-02); MFI (230 ° C, 2.16 mg) PP fiber was 20 g / 10 min. PP coating was obtained from BASF (Novel 1100 VC). MFI (230 ° ^ 2.16 mg)<sup>and</sup>eco, e2la PP was 1<sup>4</sup>0 g / 10 min. The fiberglass content of the mixture was 37.5% by weight, PPmfmoo to PP weight ratio<sub>MF</sub>i = ioo was 4: 1. MFI PP in the month and month was 70 g / 10 min. The pellet length was 12 mm.
The material was dispersed in a Stork injection molding machine with the same settings as in Example 1 <sup>s</sup> injected into the mold on a plate, which is 4 mm thick, through a converging nozzle. Immediately after injection, the mold operated at a linear speed of 0.08 mm / s over a 3.1 mm path. After the cooling time, during which the entire compact has cooled to a temperature below the softening point of PP, the mold was opened further and the compact was pushed out.
It was found that the compacted foam evenly and had a thickness of 7.1 mm, density 567 kg / m<sup>3</sup> and a porosity of 54%. Ori2aj module<sup>and</sup>cy (E) was 22555 MPa, solid<sup>and</sup>The death rate was 46.9 MPa and elongation at break (eb<sub>mk</sub>) was 3.1%. The specific properties were: Esp = 11.2 and Ospec = 4.0. The surface was completely smooth and did not contain pores on both sides.
Example III.
The material, injection molding machine settings and injection procedure and including injection were the same as in Example 2. However, the thickness of the mold was 3 mm instead of 4 mm.
Immediately after injection, the mold was opened at a linear speed of 0.08 mm / s over a 1.9 mm path. After the cooling time, the mold was opened further and the compact was pushed out.
It was found that the compacted foam evenly and had a thickness of 4.9 mm, density 610 kg / m<sup>3</sup> and porosity 51%. The bending modulus (E) was 2689 MPa, the flexural strength was 55.5 MPa and the elongation at break was 3.4%. The specific properties were: 610, pca<sub>S</sub>Fri.<sub>C</sub> = 3, on The surface was always half-hearted by both eyes.
Comparative Example A.
The material, injection molding machine settings and procedure were the same as in Example 1, but now the entire compact is cooled immediately after injection to a temperature below the softening point PP without partial opening of the mold. After the cooling time, the mold was opened completely and the molding was pushed out.
The compact had a thickness of 4.0 mm, a density of 1028 kgW and a porosity of 16%. The bending modulus of the plate was 4266 MPa, the flexural strength was 110.9 MPa and the elongation at break was 4.0%. The proper properties were as follows: E<sub>spec</sub> = 7.4 o<sub>sp</sub>ec = 3.1. The surface completely did not contain pores and had low specific properties. The porosity was 16% and was a consequence of the voids created because no clamping pressure was applied.
Comparative Example B.
The material, injection molding machine settings and procedure were the same as in test A, however, a compression pressure of 3.5 MPa (35 bar) was used within 10 seconds immediately after injection. After the cooling time, the mold was opened completely and the molding was pushed out.
The non-foamed compact had a thickness of 4.0 mm, a density of 1225 kg / m3 and a porosity of 0%. The flexural modulus was 6720 MPa, flexural strength 17.39 MPa and elongation at break was 4.0%. The specific properties were: E ^ = 7.2 io<sub>sp</sub>ce = 3.4. The surface had no pores and was smooth on both sides. This test shows that the porosity of the compact in test A was a consequence of the lack of clamping pressure.
Comparative Example C.
The material, injection molding machine settings and procedure were the same as in Example 1, however, a compression pressure of 3.5 MPa (35 bar) was used within 10 seconds immediately after injection. Immediately thereafter, the mold was opened partially at a linear speed of 0.08 mm / s over a 3.1 mm path. After the cooling time, the mold was opened completely and the molding was pushed out.
The compact has uneven, porous platter surfaces on both sides of which the glass fibers protrude. The thickness varies from 4 to 7.1 mm. The density is below 1000 kg / m3. This shows that the use of clamping pressure does not allow uniform foaming of the compact. Within 10 s during which the clamping pressure was applied, the compact cooled so much that it was no longer a mixture with a temperature above the softening point PP between the two surfaces of the plate.
Comparative Example D.
The injection molding machine settings and procedure were the same as in Example 1, but now another material was used, namely Śtamylan P 112MN40 with MFI 47 g / 10 min and containing 40% by weight of short glass fibers from 0.1 to 0.3 mm in length .
Immediately after injection, the mold was opened at a linear speed of 0.08 mm / s over a 3.1 mm path. After the cooling time, the mold was opened further and the molding was pushed out. The compact did not foam, did not take the form of a mold and had a porosity of 12%. This shows that the glass fibers used are between 0.1 and 0.3 mm in length too short to allow the compact to foam.
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Example IV
The procedure and settings of the injection molding machine were the same as in Example II, but now the following cylinder temperature settings were used: loading hopper / zone 1 / zone 2 / zone 3 / zone 4 / zone 5 / head are in turn 40/280/290/310 / 325/325/325 ° C. .
The material used in this example was Fiberstran Gl / 40 from DSM Engineering Plastics, USA (pultrusion granulate, consisting of polyamide with M<sub>n</sub> 25,000 g / mol and containing 40% by weight of glass fibers.
Immediately after injection, the mold was opened with a line speed of 0.55 mm / s over a path length of 3.1 mm. After the cooling time, the mold was opened further and the molding was pushed out.
It was found that the compacted foam evenly and had a thickness of 6.1 mm, density 625 kg / m<sup>3</sup> and a porosity of 57%. Mechanical properties were measured using dry samples. The bending module of the plate was 4400 MPa, the bending strength was 85 MPa and the elongation at break was 3.2%. The proper properties were as follows: Ejpj ,. = 12.2 and Gspec = 4.7. The surface did not contain pores and was smooth on both sides.
Example V.
The injection molding machine settings and procedure were the same as in Example IV.
The material used in this example was Celstran N66C40-01-04, a PCI / Hoechst-Celanese pultrusion material consisting of PA 6.6 oM<sub>n</sub> above 5000 g / mol and containing 40% by weight of carbon fibers.
Immediately after injection, the mold was opened with a linear speed of 0.55 mm / s over a 2.7 mm path. After the cooling time, the mold was opened further and the molding was pushed out.
It was found that the compacted foam foamed evenly and had a thickness of 5.7 m, a density of 671 kg / m3 and a porosity of 50%. Mechanical properties were measured using dry samples. The bending modulus of the plate was 8600 MPa, the flexural strength was 110 MPa and the elongation at break was 2.9%. The correct properties were: E<sub>S (</sub>p<sub>t</sub> = 14.2 and Hspec = 4.9. The surface did not contain pores and was smooth on both sides.
Example VI.
A compact was produced using as a material a mixture consisting of rovings of PP-coated glass fibers. Fiber glass roving fiber was obtained from Vefrotex and in addition to glass fibers continuous PP fibers (Twmtex, R PP75 630-02) were introduced; The MFI of the PP fiber was 20 g / 10 min. PP coating was obtained from Montell Valtec HH442H). The MFI of the PP coating was 700 g / 10 min. The fiberglass content of the mixture was 37.5% by weight, the ratio was PPmfi = ioq to PP<sub>mh</sub>= q was 4: 1. MFI PP in the mixture was 340 g / 10 min. The pellet length was 12 mm. The moisture content of the mixture measured by Karl Fischer method was below 100 ppm.
As an injection molding machine, the Stork injection molding machine described above was used with the following settings; cylinder temperatures - loading hopper / zone 1 / zone 2 / zone 3 / zone 4 / zone 5 / head are respectively: 40/190/210/230/270/285/285 ° C; mold temperature 85 ° C; speed of 40 revolutions per minute; dosing path 110 mm; back pressure of 1 0.1 MPa (1 bar); pressing pressure missing; cooling time from 60 to 80 s; injection speed 100 mm / s; dispensing time 25 s; loading rate 100%.
The material was dispersed in an injection molding machine and injected into a mold on a plate, which was 2 mm thick, through a converging nozzle. Immediately after injection, the mold was opened at a linear speed of 0.1 mm / s over a path length of 1.8 mm. After the cooling time, during which the entire compact has cooled to a temperature below the processing temperature of PP, the mold was opened further and the compact was pushed out. It was found that the compacted foam evenly and had a thickness of 3.8 mm, a density of 645 kg / m3 and a porosity of 40%. The bending modulus was 3105 MPa, the flexural strength was 54.5 MPa and the elongation at break was 3.9%. The specific properties were: E. ^ = 10.5 in<sub>S</sub>pec - 3.6. The surface had no pores and was smooth on one side, and porous and smooth on both sides.
Example VII.
The injection molding machine settings were the same as in Example 6, but there was another way in which the mold opens immediately after injection. The material is also the same as
185 405 in the previous example. Immediately after injection, the mold was opened at a linear speed of 0.1 mm / s over a 2.9 mm path. After the cooling time, during which the entire compact has cooled to a temperature below the processing temperature of PP, the mold was opened further and the compact was pushed out. The compact surface was not completely free of pores on both sides.
Example VIII.
The injection molding machine settings were the same as in Example 6, but the path on which the mold opens immediately after injection was different. The material is also the same as in the first example, with the difference that the measured moisture content was 2732 pmm.
Immediately after injection, the mold was opened with a linear speed of 0.1 mm / s over a 2.9 mm path. After the cooling time, during which the entire compact has cooled to a temperature below the processing temperature of PP, the mold was opened further and the compact was pushed out.
It was found that the compacted foam foamed evenly and had a thickness of 4.9 mm, density 490 kg / m<sup>3</sup> and 60% porosity. The flexural modulus was 1869 MPa, the flexural strength was 31.5 MPa and the elongation at break was 3.7%. The proper properties were as follows: E<sub>spec</sub> = 11.7 and Cspec = 3.6. The surface did not contain any pores and was smooth on both sides.
Comparative Example E.
The injection molding machine settings were the same as in Example 6, but there was another way in which the mold opens immediately after injection. The material is also the same as in the first example, except that the measured moisture content was 5600 pmm. Immediately after injection, the mold was opened at a linear speed of 0.1 mm / s over a 2.9 mm path. After the cooling time, during which the entire compact has cooled to a temperature below the processing temperature of PP, the mold was opened further and the compact was pushed out. The specific properties were: Espec = 9.7 ia<sub>S</sub>full<sub>C</sub> = 3.4. The surface had no pores on either side and showed a significant number of cavity marks on the surface caused by trapped and undissolved moisture.
The table below shows the properties of the parts produced in the examples and comparative tests.
Table
<td>Example / comparative example</td><td>E-spec</td><td>σ-spec</td>
<td>AND</td><td> 10,2</td><td> 3,5</td>
<td>II</td><td> 11,2</td><td> 4,0</td>
<td>II</td><td> 10,6</td><td> 3,9</td>
<td>AND</td><td> 7,4</td><td> 3,1</td>
<td>B</td><td> 7,2</td><td> 3,4</td>
<td>C</td><td>ND</td><td>ND</td>
<td>D</td><td>ND</td><td>ND</td>
<td>IV</td><td> 12,2</td><td> 4,7</td>
<td>V</td><td> 14,2</td><td> 4,9</td>
<td>VI</td><td> 10,5</td><td> 3,6</td>
<td>VII</td><td>ND</td><td>ND</td>
<td>VIII</td><td> 11,7</td><td> 3,6</td>
<td>E</td><td> 9,7</td><td> 3,4</td>
ND not specified
It can be seen from the cited table that the compacts produced according to the invention have higher specific strength and bending modulus values.
185 405
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32 members in 12 offices
Priority claims8
| Document | Office | Kind | Date |
|---|---|---|---|
| 1004268 | Netherlands (Kingdom of the) | A | |
| 1004268 | Netherlands (Kingdom of the) | A | |
| 9700576 | Netherlands (Kingdom of the) | W | |
| 9700576 | Netherlands (Kingdom of the) | W | |
| 961004268 | – | – | – |
| 97NL9700576 | – | – | – |
| NL19961004268 | – | – | – |
| WO1997NL00576 | – | – | – |
Members32
| Document | Office | Kind | |
|---|---|---|---|
| NL1004268C2 | Netherlands (Kingdom of the) | C2 | |
| WO9816359A1 | World Intellectual Property Organization (WIPO) | A1 | |
| WO9816366A1 | World Intellectual Property Organization (WIPO) | A1 | |
| AU4576597A | Australia | A | |
| AU4576697A | Australia | A | |
| NL1006363C2 | Netherlands (Kingdom of the) | C2 | |
| EP0934143A1 | European Patent Office (EPO) | A1 | |
| EP0934150A1 | European Patent Office (EPO) | A1 | |
| PL332698A1 | Poland | A1 | |
| PL332703A1 | Poland | A1 | |
| SK48699A3 | Slovakia | A3 | |
| CZ129099A3 | Czechia | A3 | |
| CZ129199A3 | Czechia | A3 | |
| HUP9904044A2 | Hungary | A2 | |
| SK48599A3 | Slovakia | A3 | |
| HUP9904334A2 | Hungary | A2 | |
| HUP9904334A3 | Hungary | A3 | |
| JP2001502259A | Japan | A | |
| JP2001504401A | Japan | A | |
| US6303070B1 | United States of America | B1 | |
| US2002025424A1 | United States of America | A1 | |
| EP0934150B1 | European Patent Office (EPO) | B1 | |
| PL185405B1This record | Poland | B1 | |
| DE69722427D1 | Germany | D1 | |
| US6605329B2 | United States of America | B2 | |
| EP0934150B9 | European Patent Office (EPO) | B9 | |
| ES2201325T3 | Spain | T3 | |
| DE69722427T2 | Germany | T2 | |
| SK284789B6 | Slovakia | B6 | |
| HU225669B1 | Hungary | B1 | |
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| JP4135982B2 | Japan | B2 |
Numbers
- Publication, DOCDB
- 185405
- Publication, EPODOC
- PL185405B
- Application
- 97332703
- Application, DOCDB
- 33270397
- Application, EPODOC
- PL19970332703
Titles2
- English
- THERMOPLASTIC MOULDING, METHOD OF MAKING SAME AND APPLICATION THEREOF
- Polish
- Spieniona wypraska termoplastyczna i sposób wytwarzania spienionej wypraski termoplastycznej
Classification
- CPC, 17
- B29C70/14
- B29B9/14
- B29K2023/12
- B29K2105/0094
- B29K2309/08
- B29K2707/04
- B29C48/92
- B29C48/00
- B29C48/03
- B29C48/04
- B29C2948/92142
- B29C2948/922
- B29C2948/92266
- Y10T428/21
- Y10T428/249993
- Y10T428/249991
- Y10T428/249989
- IPC, 6
- B29B9 14
- B29C45 78
- B29C48 025
- B29C45 64
- B29C48 92
- B29C70 14