DE102009025366B4 - Process for producing a long fiber reinforced thermoplastic profile and apparatus therefor - Google Patents

Abstract

A method of producing an LFT (long fiber reinforced thermoplastic) profile which manufactures and comprises the LFT profile sequentially by using a forming roll assembly and an LFT-D (long fiber reinforced thermoplastic direct compounding) extruder having a first extruder and a second extruder a) preparing a thermoplastic resin compound by melting and kneading a thermoplastic resin and an additive in the first extruder; b) preparing an LFT by kneading the prepared thermoplastic resin compound and continuous fibers or staple fibers in the second extruder; c) preparing an extruded LFT product having a desired size and shape by continuously extruding the LFT using an extrusion die; and d) forming a profile of a desired size and shape by passing the extruded LFT product through the forming roll assembly and then cutting it using a cutting member, characterized in that the forming roll assembly comprises at least three pairs of rolls, each temperature of the roll pairs from the extruder becomes progressively lower, the pairs of rollers are designed so that all pressing spaces of the same have different cross-sectional shapes which are progressively smaller, so that the pressing space of the last pair of rollers has the same cross-sectional shape as the profile to be produced, at one end of a roller pair having roll forming a drawing unit is arranged, and the drawing unit pulls the extruded product at a constant speed.

Description

BACKGROUND OF THE INVENTION

Field of the invention

The present invention relates to a method for producing a long fiber reinforced thermoplastic profile having the features of the preamble of claim 1 and an apparatus for producing a long fiber reinforced thermoplastic profile having the features of the preamble of claim 6. More particularly, the present invention relates to a method for producing a long fiber reinforced thermoplastic profile combines a LFT-D (long fiber reinforced thermoplastic direct compounding) method and a roll forming process, and economically and sequentially produces the long fiber reinforced thermoplastic profile, thereby reducing degradation of the thermoplastic profile, and an apparatus therefor.

Description of the Related Art

A profile is used for building constructions and vehicles and made by extruding steel, aluminum or a plastic compound or by roll forming them.

In the roll forming method, a continuously fed sheet material is gradually formed into a circular cross-sectional shape by passing it through roll stands continuously arranged to make the profile, or both ends thereof are welded to make a tube.

Typically, the rolls used in the roll forming process have a convex roll and a concave roll through which a pressing part and a non-pressing part are selectively arranged so that the sheet material is gradually formed into a desired shape by passing it through the roll pairs becomes. The rollers can be used restrictively when working with metals.

A long-fiber-reinforced thermoplastic (hereinafter referred to as "LFT") is used for vehicle components such as an impact beam and a plate frame which is thin and has a light weight and excellent strength characteristics. The LFT is manufactured by an LFT-D process.

First, the LFT is made to have a sheet shape. The sheet-shaped LFT is heated in an oven, coated with a reinforcing sheet, and then molded into the impact beam and the like by a high-pressure molding apparatus. However, there is a problem that the physical properties are deteriorated during the heating in the furnace.

The DE 101 05 812 A1 discloses a process for producing a sheet semifinished product from glass fiber reinforced thermoplastics by feeding thermoplastic melt and endless glass fiber rovings, which are preimpregnated with a partial stream of the thermoplastic melt, into an extruder, crushing the glass fibers and mixing with the thermoplastic melt, Squeezing the mixture and forming a flat semi-finished product.

The DE 101 29 224 C1 discloses a method for producing a semi-finished product from a Sheet Molding Compound (SMC) material and includes raw material processing and semi-finished product manufacturing. The raw material is processed by one or more extruders. The raw material is introduced directly through the extruder or extruders in a forming tool for the production of the semifinished product. Raw material processing and semifinished product production take place in a single process step.

The DE 43 30 860 A1 discloses a sheet glass mat reinforced thermoplastic sheet in which more than 50% by weight of the glass fibers are more than 2 mm in length and more than 5% by weight have a length of less than 2 mm, but practically no fibers are longer than 50 mm, as well as a process for producing this semi-finished product, in which thermoplastic and glass fibers are extruded and a sheet is formed.

The DE 20 2006 017 392 U1 discloses a component made of natural fiber reinforced plastic, in particular a reinforcement for reinforcing bodies of mineral, hydraulically curing mixtures, which has a cross section adapted to the stress and a rough and / or embossed surface improving the adhesive bond and of a thermosetting or thermosetting matrix with a proportion of natural fibers up to 80% by mass.

SUMMARY OF THE INVENTION

An embodiment of the present invention is directed to providing a method for producing an LFT profile that combines an LFT-D process and a roll forming process to economically and sequentially produce the long fiber reinforced thermoplastic profile, thereby reducing degradation of the thermoplastic profile and a Provide device for it.

In order to achieve the object of the present invention, the present invention provides a method of manufacturing an LFT (long fiber reinforced thermoplastic) profile according to claim 1 and an apparatus for manufacturing an LFT profile according to claim 6.

BRIEF DESCRIPTION OF THE DRAWINGS

1 FIG. 10 is a schematic diagram showing a device for manufacturing an LFT profile according to an embodiment of the present invention and the manufactured profile in cross section. FIG.

2 FIG. 12 is a schematic view showing a pair of rollers according to an embodiment of the present invention and the formed profile in cross section. FIG.

LIST OF REFERENCE NUMBERS

100

LFT-D extruders

101

thermoplastic resin and additive

102

first extruder

103

continuous fiber

104

second extruder

105

extrusion die

200

Rolling molding

201

upper roller

202

lower roller

203

Press room

300

cutting part

400

cutting part

401

Profile 1

DESCRIPTION OF SPECIFIC EMBODIMENTS

The advantages, features and aspects of the invention will become apparent from the following description of the embodiments with reference to the accompanying drawings, which will be presented below.

According to the present invention, there is provided a method of producing an LFT (long fiber reinforced thermoplastic) profile which successively uses the LFT profile by using a forming roll assembly and an LFT-D (long fiber reinforced thermoplastic direct compounding) extruder comprising a first extruder and a first extruder second extruder, produces and includes: a) preparing a thermoplastic resin compound by melting and kneading a thermoplastic resin and an additive in the first extruder; b) preparing an LFT by kneading the prepared thermoplastic resin compound and continuous fibers or staple fibers in the second extruder; c) preparing an extruded LFT product having a desired size and shape by continuously extruding the LFT using an extrusion die; and d) forming a profile of a desired size and shape by passing the extruded LFT product through the forming roll assembly and then cutting it using a cutting member.

The LFT-D extruder includes the first and second extruders. If it is possible to melt and knead the thermoplastic resin and the additive and then transfer them to the second extruder, the first extruder is not particularly limited. And if it is possible to knead the thermoplastic resin compound and the continuous fibers or staple fibers, the second extruder is not particularly limited.

The first and second extruders are separated according to their functions. Preferably, each extruder is provided several times. However, only one extruder can be used, which includes all functions.

The thermoplastic resin may be one or more of a group of polyolefin, polyamide, ABS resin, polyethylene terephthalate and the like. Preferably, the thermoplastic resin is polyolefin.

The additive may be one or more of a group of an antioxidant, a heat stabilizer, a pigment, a dispersant, a compatibilizer, and the like.

The continuous fiber or staple fiber may be one or more of a group of a glass fiber, a basalt fiber, a carbon fiber, an aramid fiber, and the like. Preferably, the continuous fiber or staple fiber is a glass fiber processed by a polyolefin surface treatment.

Preferably, the extrusion die has a cross-sectional shape and a size that are similar to or identical to a cross-sectional shape and a size of a profile to be produced.

Each pair of rollers consists of an upper roller, a lower roller and a pressing space (a space between the upper and lower rollers). The upper and lower rollers form a pair that is to be rotated together. Outer surfaces of the upper and lower rollers of the last pair of rollers are designed so that the pressing space has a cross-sectional shape which is identical to that of a profile to be produced.

When the upper and lower rollers are rotated, the outer surfaces of the upper and lower rollers and the pressing space are not changed.

Three or more pairs of rollers are provided and each temperature thereof is gradually lowered from the extruder. For example, in the case of three pairs of rollers, the temperature of the pairs of rollers may be from about 200 ° C, 150 ° C and 100 ° C in order from the closest to the extruder.

The plurality of roller pairs are designed so that all the pressing spaces of the same have different cross-sectional shapes, which are progressively smaller, so that the pressing space of the last pair of rollers has the same cross-sectional shape as the profile to be produced.

The upper and lower rolls and the pressing space may be made different according to the shape and size of the profile to be produced.

A drawing unit (for drawing the extruded product at a constant speed) is disposed at one end of the rolled molding. This will cause a bad percentage to be reduced.

A plastic sheet may optionally be coated on top and bottom surfaces of the extruded LFT product prior to the roll forming operation, and then the extruded LFT product is treated by the roll forming.

The profile may be used as a structural profile, a complex rectangular material or a vehicle impact beam, and the like.

An apparatus for manufacturing the LFT profile according to the present invention includes an LFT-D extruder having first and second extruders, a forming roll assembly, and a cutting member sequentially arranged to sequentially produce the LFT profile.

The first and second extruders are separated according to their functions. Preferably, each extruder is provided several times. However, only one extruder can be used, which includes all functions.

1 FIG. 10 is a schematic diagram showing a device for manufacturing an LFT profile according to an embodiment of the present invention and the manufactured profile in cross section. FIG.

The like in 1 The apparatus for producing the LFT profile shown includes an LFT-D extruder 100 , a rolled part 200 and a cutting part 300 , The LFT-D extruder 100 includes a first extruder 102 and a second extruder 104 and the rolled molding 200 includes an upper roller 201 , a lower roller 202 and a press room 203 ,

The first extruder 102 is provided with a single screw, so a thermoplastic resin and an additive 101 to melt and knead and then to the second extruder 104 to convict.

When a processing temperature and rpm (revolutions per minute) in melting and kneading are the same as those typically used for the thermoplastic resin and the additive used, they are not particularly limited. Preferably, they are within such a range of values as to minimize deterioration of the thermoplastic resin compound and to perform kneading uniformly.

The second extruder 104 is equipped with a twin screw so as to feed a continuous fiber 103 and those from the first extruder 104 kneading introduced thermoplastic resin compound and then continuously extruding an LFT product having a desired size and shape by extruding the LFT by using an extrusion die 105 manufacture.

The endless fiber 103 is cut in the kneading process into a long fiber of a desired size so that it passes through the extrusion die 105 extruded product with sufficient strength, and the long fiber is subjected to high shear stress in the extruder.

The extruded product 106 has a cross-sectional shape, an outer shape and a size that are similar to an end profile to be produced. However, since the extruded product 106 is widened by the spring force of the long fiber, it does not have the same dimensions as the final profile.

The extruded product 106 is in the rolled part 200 introduced, which has three pairs of rollers, each from the upper roller 201 , the bottom roller 202 and the press room 203 exist, and through the upper and lower rollers 201 and 202 pressed while being cooled slowly, thereby having the same cross-sectional shape, the same outer shape and the same size as the end profile, and then through the cutting part 300 cut into a desired length, creating a continuous profile 400 produced according to the present invention.

2 FIG. 12 is a schematic view showing a pair of rollers according to an embodiment of the present invention and the formed profile in cross section. FIG.

The pair of rollers consists of the upper roller 201 , the bottom roller 202 and the press room 203 , The product extruded through the LFT-D extruder 106 is so in the press room 203 Introduced it through the top and bottom rollers 201 and 202 is pressed, making it the same cross-sectional shape, the same outer shape and the same size as the baling chamber 203 and then through the cutting part 300 cut into a desired length, whereby a final profile-1 401 produced according to the present invention.

According to the present invention, it is possible to provide a method for producing a long-fiber-reinforced thermoplastic profile which combines an LFT-D method and a roll-forming method and economically and sequentially produces the long-fiber-reinforced thermoplastic profile, thereby reducing deterioration of the thermoplastic profile, and providing a device therefor.

While the present invention has been described with respect to the specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the scope of the invention as defined in the following claims.

Claims (6)

A method of producing an LFT (long fiber reinforced thermoplastic) profile which manufactures and comprises the LFT profile sequentially by using a forming roll assembly and an LFT-D (long fiber reinforced thermoplastic direct compounding) extruder having a first extruder and a second extruder a) preparing a thermoplastic resin compound by melting and kneading a thermoplastic resin and an additive in the first extruder; b) preparing an LFT by kneading the prepared thermoplastic resin compound and continuous fibers or staple fibers in the second extruder; c) preparing an extruded LFT product having a desired size and shape by continuously extruding the LFT using an extrusion die; and d) forming a profile of a desired size and shape by passing the extruded LFT product through the forming roll assembly and then cutting it using a cutting member, characterized in that the forming roll assembly comprises at least three pairs of rolls, each temperature of the roll pairs from the extruder becomes progressively lower, the pairs of rollers are designed so that all pressing spaces of the same have different cross-sectional shapes which are progressively smaller, so that the pressing space of the last pair of rollers has the same cross-sectional shape as the profile to be produced, at one end of a roller pair having roll forming a drawing unit is arranged, and the drawing unit pulls the extruded product at a constant speed. The method of claim 1, wherein the thermoplastic resin is one or more of a group consisting of polyolefin, polyamide, ABS resin and polyethylene terephthalate. The method of claim 1, wherein the additive is one or more of a group consisting of an antioxidant, a heat stabilizer, a dispersant, a compatibilizer, and a pigment. The method of claim 1, wherein the fiber is one or more of a group consisting of glass fiber, basalt fiber, carbon fiber and aramid fiber. A method according to claim 1, wherein an upper and a lower surface of the extruded article produced in c) are coated with a plastic sheet and then the extruded product is passed through the forming roll assembly with the plastic sheet. An apparatus for producing an LFT (long fiber reinforced thermoplastic) profile comprising an LFT-D (long fiber reinforced thermoplastic direct compounding) extruder having a first extruder and a second extruder, a forming roll assembly, and a cutting member sequentially arranged to successively produce the LFT profile, characterized in that the forming roller assembly comprises at least three pairs of rollers, wherein the device is arranged so that during operation of the same each temperature of the roller pairs from the extruder is gradually lower, the roller pairs are designed so that all pressing spaces same different ones Have cross-sectional shapes which are progressively smaller, so that the pressing space of the last pair of rollers has the same cross-sectional shape as the profile to be produced, and at one end of a pair of rolls having a rolling unit is arranged a drawing unit for pulling an extruded product at a constant speed.

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