KR20220126848A - Lightweight composite material using closed structure PET foam or PP foam and its manufacturing method - Google Patents

Abstract

The present invention relates to a lightweight composite material which is lightweight and has excellent mechanical properties and sound insulation properties by combining a foam sheet and non-woven fabric of a closed structure, and a manufacturing method thereof. The lightweight composite material consists of: a skin layer made of PET non-woven fabric or PP non-woven fabric; a PET bonding layer; a sound insulation layer made of a foam sheet having a closed structure of PET or PP; a PET bonding layer; and a back layer made of a PET non-woven fabric or a PP non-woven fabric layer. The lightweight composite material using the foam sheet having a closed structure according to the present invention improves mechanical properties, such as flexural strength and flexural modulus, without significantly increasing the weight per unit area by adopting the foam of a closed structure.

Description

Lightweight composite material using closed structure PET foam or PP foam and its manufacturing method

The present invention relates to a lightweight composite material using a closed structure PET foam or PP foam and a manufacturing method thereof, and specifically, to a lightweight composite material using a closed structure PET foam or PP foam and mechanical properties And it relates to a lightweight composite material having excellent sound insulation properties and excellent moldability with little distortion after molding, and a method for manufacturing the same.

As the megatrend of the industry is progressing in the direction of eco-friendliness and human-friendliness, eco-friendliness, lightweight, which is the biggest task of the automobile industry, responds to environmental friendliness, light weight and high durability in materials used for transportation equipment such as automobiles, trains, and airplanes. And development of lightweight composite materials for high durability is required.

Non-woven composite materials have been widely used as sound absorbing and insulating materials to block vehicle noise. The demand for a nonwoven composite material that has good mechanical properties and can effectively block and reduce noise is increasing.

Non-woven composite materials used as interior and exterior materials for vehicle sound absorption and insulation have various structures and are manufactured in various forms depending on the location where they are mounted on the vehicle. The lightweight composite sheet is attached to at least one surface of the inner layer 2 and 40 to 90% by weight of the base material and 10 to 60% by weight of the natural fiber integrally formed therein, and the base material is 60 to 80% by weight. Disclosed is a lightweight composite board for automobile interior materials, characterized in that the skin layer (1, 3) is integrally composed of weight%, 15 to 25% by weight of polyester, and 5 to 15% by weight of natural fibers.

In Patent Document 2, it consists of a PET (polyethylene terephthalate) foam sheet having a foaming ratio of 10 to 30, a core layer having a thickness of 2 to 8 mm, and a PET foam sheet having a foaming ratio of 2 to 10, and having a thickness of 1 to Light weight and molding, characterized in that it comprises a pair of reinforcing layers bonded to the upper and lower surfaces of the core layer by heat lamination, and a polyester-based nonwoven fabric bonded to one surface of the reinforcing layer. Disclosed is a substrate for a vehicle interior material having excellent properties, and by forming an inorganic fiber mat on one or both sides of a foam layer formed of a polyester resin foam in Patent Document 3, it has a thin thickness and excellent light weight, flame resistance, flexural strength, Disclosed is an interior and exterior material for a vehicle having characteristics such as sound absorption and sound insulation.

Polyester foam seat|seet is included in patent document 4; The polyester foam sheet has a structure in which an average of 20 or more non-penetrating holes are formed per unit area of 1 cm in width and 1 cm in length on the surface; The non-penetrating hole has a depth in the range of 20 to 80% of the thickness of the polyester foam sheet, an average diameter of 1 mm or less, and a ratio of the average diameter to the average depth of 1.5 to 4.8. is starting

The inventor of the present invention completed the present invention by confirming that a lightweight nonwoven composite material by a combination of a synthetic resin sheet having a closed structure is suitable as a composite material for vehicles because it is lightweight and has good mechanical properties.

US 10-1015513 B1 US 10-1567777 B1 US 10-1997617 B1 US 10-2006415 B1

The problem to be solved in the present invention relates to the provision of a lightweight composite material using a closed structure PET foam or PP foam and a manufacturing method thereof, and specifically, a PET foam or PP foam having a closed structure. The combination of sheet and nonwoven fabric improves flexural strength and flexural modulus, thereby reducing the thickness and reducing the weight. It is intended to provide a method.

As a means of solving the problems according to the present invention, a lightweight composite material using PET foam or PP foam having a closed structure is a nonwoven fabric layer as an outer layer, a foam sheet layer having a closed structure as a sound absorbing and insulating layer, and a back surface It is made of a lightweight composite material that is combined by sequentially stacking nonwoven layers in layers.

One embodiment of a lightweight composite material using a PET foam or PP foam having a closed structure according to the present invention is a skin layer made of polyethylene terephthalate (PET) nonwoven fabric or polypropylene (PP) nonwoven fabric, PET bonding layer, polyethylene A sound insulation layer made of PET foam or PP foam sheet having a closed structure of terephthalate (PET) or polypropylene (PP), a PET bonding layer, and a back layer made of a polyethylene terephthalate (PET) nonwoven fabric or polypropylene (PP) nonwoven fabric layer consists of including

Another embodiment of a lightweight composite material using a PET foam or PP foam having a closed structure according to the present invention has a weight of 180 to 1000 g/ m 2 of a skin layer, a PET bonding layer, a sound insulation layer with a weight of 100 to 1000 g/m 2 composed of a foam sheet with a closed PET or polypropylene (PP) structure, a PET bonding layer, and a PET nonwoven fabric or polypropylene (PP) nonwoven fabric having a weight of 100 to 1000 g/m 2 It consists of including a back layer of 180 ~ 1000g/m2.

A method of manufacturing a lightweight composite material using PET foam or PP foam having a closed structure as a means of solving another problem of the present invention is a). Preparing a skin layer and a back layer by preparing a nonwoven fabric having a weight of 180 to 1000 g/m 2 using polyethylene terephthalate (PET) fibers or polypropylene (PP) fibers, b). A closed structure PET foam or PP foam sheet is manufactured by foaming the melted resin melted by mixing PET or PP with a crosslinking agent, antioxidant and filler together with a foaming agent to form a sound insulation layer with a weight of 100 to 1000 g/m2. preparing and c). PET latex resin or PET powder is applied or sprayed on the surface bonded to the sound insulation layer of the closed structure PET foam or PP foam sheet in the prepared skin layer and the back layer, and then the closed structure foam Using a PET foam or PP foam sheet as an intermediate layer, sequentially stacking a surface layer, a sound insulating layer, and a back layer, and laminating and bonding while heating.

The lightweight composite material using PET foam or PP foam having a closed structure according to the present invention is lightweight and has excellent sound insulation, and mechanical properties such as flexural strength and flexural modulus are good, It is particularly suitable as a composite material for the trunk side and trunk partition.

The lightweight composite material using PET foam or PP foam having a closed structure according to the present invention has improved flexural strength and flexural modulus, so that it can be reduced in thickness and reduced in weight.

The lightweight composite material using PET foam or PP foam having a closed structure according to the present invention has excellent sound insulation properties due to the closed structure foam.

The existing foam sheet forms a non-woven fabric layer on only one surface of the skin layer, so there is a problem in that distortion occurs after molding. It has the advantage of being able to suppress distortion after forming into a desired shape by forming a non-woven fabric layer on it.

1 is a laminated structure of a lightweight composite material according to the prior art;
2 is a laminated structure of a lightweight composite material according to the present invention;
3 is an example of a trunk side interior material to which a lightweight composite material according to the present invention is applied;
4 is a graph comparing the sound insulation performance of the lightweight composite material according to the prior art and the present invention;

Hereinafter, the present invention will be described in more detail with reference to specific contents for carrying out the present invention, but the present invention is not limited by the contents and examples described below.

The lightweight composite material using PET foam or PP foam having a closed structure according to the present invention is a polyethylene terephthalate nonwoven fabric or a polypropylene nonwoven fabric with a weight of 180 to 1000 g/m 2 of the skin layer (1), polyethylene terephthalate bonding A sound insulating layer (2) with a weight of 100 to 1000 g/m2, a polyethylene terephthalate bonding layer, and a polyethylene terephthalate or polypropylene non-woven fabric having a weight of 180 to 1000 g It consists of including the back surface layer 3 of /m<2>.

The polyethylene terephthalate (PET) or polypropylene (PP) nonwoven fabric of the outer layer (1) and the back layer (3) according to the present invention is a widely known nonwoven fabric manufacturing method using short fibers of 2 to 10 denier as a raw material. A nonwoven fabric having a weight of 180 to 1000 g/m 2 is manufactured by a carding process, a web forming process and a web bonding (adhesive) process, and is not particularly limited. The skin layer 1 is preferably a nonwoven fabric having a thickness of 180 to 450 g/m 2 . The back layer 3 is preferably a nonwoven fabric having a thickness of 180 to 400 g/m 2 .

The polyethylene terephthalate bonding layer according to the present invention uses low-melting adhesive polyethylene terephthalate latex or polyethylene terephthalate powder, and the outer layer (1) and the sound insulating layer (2), the back layer (3) and the sound insulating layer (2) acts as an adhesive to bond them together.

The sound insulation layer 2 according to the present invention is made of a closed structure PET foam or PP foam sheet foamed with polyethylene terephthalate (PET) or polypropylene (PP), and exhibits a sound insulation function. The sound insulating layer (2) is preferably a foam sheet of 150 ~ 400g / m2.

In general, closed structure foam has high compressive strength, is light and flexible, strong and durable enough to withstand a large amount of pressure without most major distortions, and has a stronger structural strength than open structure foam. There are characteristics. The closed structure foam of the present invention has high sound insulation properties, while the open foam foam has high sound absorption properties.

The sound insulation layer 2 of the present invention reduces the weight per unit area by the material and structural characteristics of the closed structure PET foam or PP foam sheet foamed with polyethylene terephthalate (PET) or polypropylene (PP). while improving mechanical properties such as flexural strength and flexural modulus

A method of manufacturing a lightweight composite material using a closed structure PET foam or PP foam according to the present invention is a). Preparing a skin layer (1) and a back layer (3) by preparing a nonwoven fabric having a weight of 180 to 1000 g/m 2 using ethylene terephthalate (PET) fibers or polypropylene (PP) fibers, respectively, b). A sound insulation layer with a weight of 100 to 1000 g/m2 ( Steps of preparing 2) and c). In the prepared skin layer and back layer, PET latex resin is applied or PET powder is sprayed on the surface that is bonded to the sound insulating layer 2 of the closed structure PET foam or PP foam sheet, and then the closed structure ( Closed Structure) of PET foam or PP foam sheet as an intermediate layer, sequentially stacking the surface layer (1), the sound insulating layer (2) and the back layer (3) in order, and laminating and bonding while heating.

The step of preparing the skin layer (1) and the back layer (3) according to the present invention, respectively, is a widely known nonwoven fabric production using ethylene terephthalate (PET) or polypropylene (PP) short fibers of 2 to 10 denier as a raw material. A nonwoven fabric having a weight of 180 to 1000 g/m 2 is produced by the carding process, web forming process and web bonding (adhesive) process, which are methods, and is not particularly limited.

The step of preparing the sound absorbing and insulating layer 2 according to the present invention consists of foaming PET or PP with a foaming agent to prepare a closed structure PET foam or PP foam sheet having a weight of 100 to 1000 g/m2. .

The PET or PP closed structure PET foam or PP foam sheet is first melted by mixing additives such as a crosslinking agent, antioxidant, and filler in a raw material resin, and then the resin melt is mixed with a foaming agent by a compressor to form a sheet. It consists of foam molding with

The PET foam or PP foam sheet of the PET closed structure is dried at 130° C. in advance to remove moisture before foaming raw PET, and is used as a crosslinking agent for 100 parts by weight of PET from which moisture has been removed in the extruder. Add 1 part by weight of mellitic anhydride, 3 parts by weight of calcium carbonate, and 0.1 parts by weight of Irganox 1010 (brand name) as an antioxidant, and heat to 280±5° C. It is manufactured by injecting butane gas and foaming it into a sheet shape.

The closed structure PET foam or PP foam sheet produced according to the present invention has a unit weight of 100 to 1000 g/m2, an average thickness of 2.5 mm, and about 97±1% of the total cells have a closed structure ( Closed Structure), and the average number of cells is 12±5 per 1mm² (average size: 450±20㎛). The foam sheet preferably has a unit weight of 150 to 400 g/m 2 .

In the laminating step according to the present invention, an adhesive resin is applied or sprayed on the surface to be adhered to the sound insulation layer in the surface layer (1) and the back surface layer (3) prepared in the previous step, and the surface layer (1) sound insulation layer using the sound absorbing and insulating layer as the central layer (2) and the back layer (3) are sequentially laminated and laminated in order, and then combined to be integrated under heating.

The adhesive resin uses a low melting point (180 ~ 250 ℃) PET latex resin or PET powder as an adhesive, and it is preferable to apply or spray the adhesive at 20 ~ 100 g/m2. The surface layer (1), the sound insulating layer (2) and the back surface layer (3) are sequentially laminated and laminated in order, and then put into a mold and combined while molding under heating.

The lightweight composite material according to the present invention has high sound insulation properties due to the closed structure of the sound insulation layer, which is the central layer, PET foam or PP foam sheet structure, has excellent light weight, and has mechanical properties such as flexural strength and flexural modulus. It is particularly suitable as a composite material for vehicle engine covers, trunk lids, trunk sides, and trunk partitions.

The composite material according to the present invention has the advantage of suppressing distortion after molding into a desired shape by a structure having a nonwoven fabric layer on the upper surface (skin layer) and the lower surface (back surface layer), It has the advantage of solving the problem of distortion after molding into the desired shape.

Hereinafter, the present invention will be described in more detail through specific <Examples> and <Test Examples>.

<Example 1>

- Fabrication of the epidermis layer and the back layer

Polyethylene terephthalate (PET) short fibers of 6 denier are carded, cross-lapping and needle-punched under the conditions shown in [Table 1] and [Table 2] below to prepare a needle nonwoven fabric (200 g/m 2 ).

Carding parameters Cross-lapping parameters Like-in 600rpm Worker 680rpm Feeding speed 700rpm stripper 500rpm Upper take off 6000rpm Outlet speed outer 6m/min inner 6.5m/min Preset value 8 kg Lower take off 650rpm Layers 22 layers upper doffer 600rpm upper table 750rpm Outlet web width 1700mm lower doffer 800rpm lower table 750rpm Inlet web width 1800mm

Needle room Needle-punching process conditions Preliminary Punching (1st) 2nd Punching 3rd Punching 4th Punching Penetration depth(mm) 11 12 13 10 In-let(m/min) 2.6 2.6 2.6 2.6 Stroke(rpm) 600 1,100 850 1,100 Out-let(m/min) 4.5 5 5.8 6.5 Needle density(#/m2) 5000 pieces/m 8000 sheets/m 8000 sheets/m 8000 sheets/m Advance/stroke(mm) 13 15 17 17 Draft rate (%) 5 8 7 8

- Production of sound insulation layer

PET foam or PP foam sheet with a closed structure of the sound insulation layer, which is the central layer, is dried at 130° C. to remove moisture before foaming the raw material PET. 100 parts by weight of PET from which moisture has been removed in the extruder 1 part by weight of pyromellitic anhydride as a crosslinking agent, 3 parts by weight of calcium carbonate, and 0.1 parts by weight of Irganox 1010 (trade name) as an antioxidant, and heated to 280 ° C. For example, it was manufactured by injecting butane gas and foaming it into a sheet shape.

Five types of specimens of thickness 1.5 mm, 2.0 mm, 3.0 mm, 3.5 mm, and 4.5 mm were prepared for the prepared closed structure PET foam sheet.

- Lamination of the skin layer, sound insulation layer, and back layer

Each of the five types of sound absorbing and insulating layers was coated with PET resin to a thickness of 100 μm, and between the five types of sound absorbing and insulating layers and the back layer was coated with PET resin to a thickness of 100 μm. A lightweight composite material using PET foam or PP foam with a total of 5 closed structures was manufactured by stacking the back layers in order.

- Molding of manufactured lightweight material

Each of the five manufactured lightweight materials was heated at a preheating temperature of 350 ° C for 80 seconds so that the skin layer and the back layer reached 180 ° C, and then placed in a lower mold cooled to a temperature of 20 ° C. then press-molded. The pressurization holding time was maintained for 1 minute and 30 seconds, and then the molded body was extracted to prepare 5 types of interior materials for vehicle trunks, which are lightweight composite materials.

<Test Example 1>

Five kinds of specimens for interior materials for vehicle trunks manufactured using the lightweight composite material in <Example 1> were prepared, and physical properties such as mechanical properties were tested on the specimens, and the results are shown in [Table 3] below.

density
200g/㎡ Room temperature (25℃) Heat treatment (80℃*24h) Heat treatment (150℃*100sec) Heat treatment (200℃*100sec) flexural strength
(N) flexural modulus
(MPa) flexural strength
(N) flexural modulus
(MPa) flexural strength
(N) flexural modulus
(MPa) flexural strength
(N) flexural modulus
(MPa) Example 1
thickness 1.5mm 4.2 348.6 8.3 146.9 4.4 39.4 12.1 112.7 Example 2
Thickness 2.0mm 6.4 372.4 11.2 122.4 16.8 147.1 19.2 108.5 Example 3
thickness 1.5mm 14.9 312.3 23.3 124.7 30.0 77.1 39.5 84.9 Example 4
thickness 1.5mm 17.1 229.2 20.5 149.6 30.8 160.7 37.6 120.0 Example 5
thickness 1.5mm 28.7 180.5 28.9 94.5 45.3 109.3 43.3 84.1

In [Table 3], each of Examples 1 to 5 according to the thickness were maintained at room temperature (25 ° C.), heat treatment (80 ° C. * 24 h) at 80 ° C. for 24 hours, and then heat treatment (150 ° C. * 100 seconds) was After holding at 150° C. for 100 seconds, heat treatment (200° C. * 100 seconds) was measured by measuring flexural strength and flexural modulus, respectively, after holding at 200° C. for 100 seconds.

Although general composite materials decrease in flexural strength and flexural modulus as the thickness decreases, the lightweight composite material using PET foam or PP foam having a closed structure according to the present invention improves flexural strength and flexural modulus. Compared to the existing composite material having a flexural modulus, it can be reduced in thickness and lighter.

4 is a graph comparing the sound insulation performance of the lightweight composite material according to the prior art of FIG. 1 and the lightweight composite material according to the present invention of FIG. 2 . It can be seen that the lightweight composite material using PET foam or PP foam having a closed structure according to the present invention has excellent sound insulation properties due to the closed structure foam.

The existing foam sheet forms a non-woven fabric layer on only one surface of the skin layer, so there is a problem in that distortion occurs after molding. It has the advantage of being able to suppress distortion after forming into a desired shape by forming a non-woven fabric layer on it.

Claims (6)

A skin layer (1) having a weight of 180 to 1000 g/m2 made of polyethylene terephthalate (PET) nonwoven fabric or polypropylene (PP) nonwoven fabric, a PET bonding layer, and a sheet of PET or polypropylene (PP) closed structure A closure comprising a sound insulating layer (2) having a weight of 100 to 1000 g/m 2 , a PET bonding layer and a backing layer (3) having a weight of 180 to 1000 g/m 2 made of PET nonwoven fabric or polypropylene (PP) nonwoven fabric Lightweight composite material using structural PET foam or PP foam. The method according to claim 1,
Polyethylene terephthalate (PET) nonwoven fabric or polypropylene (PP) nonwoven fabric is a lightweight composite material using PET foam or PP foam of a closed structure, characterized in that it is composed of short fibers of 2 to 10 denier, respectively. 3. The method according to claim 2,
The polyethylene terephthalate (PET) or polypropylene (PP) closed structure PET foam or PP foam sheet has an average thickness of 2.5 mm, and about 97±1% of the total cells have a closed structure, A lightweight composite material using PET foam or PP foam with a closed structure, characterized in that the average number of cells is 12±5 per 1㎟, and the average size is 450±20㎛. a). Preparing a skin layer (1) and a back layer (3) by preparing a nonwoven fabric having a weight of 180 to 1000 g/m2 using polyethylene terephthalate (PET) fibers or polypropylene (PP) fibers, respectively;
b). preparing a sound insulation layer 2 having a weight of 100 to 1000 g/m 2 by manufacturing a foam sheet having a closed structure by foaming PET or PP; and
c). PET latex resin is applied or PET powder is sprayed on the surface that is joined to the sound insulating layer 2 of the closed structure foam sheet in the prepared skin layer 1 and the back layer 3, and then the closure Using the sound insulation layer 2 of the closed structure foam sheet as an intermediate layer, the surface layer 1, the sound insulation layer 2, and the back surface layer 3 are sequentially laminated in that order, and the lamination step of laminating and bonding while heating A method of manufacturing a lightweight composite material using a closed structure PET foam or PP foam, comprising: 5. The method according to claim 4,
Polyethylene terephthalate (PET) nonwoven fabric or polypropylene (PP) nonwoven fabric is a method of manufacturing a lightweight composite material using a closed structure PET foam or PP foam, characterized in that each is made of short fibers of 2 to 10 denier. 6. The method of claim 5,
The sound insulation layer 2 is dried at 130° C. to remove moisture before foaming polyethylene terephthalate (PET), and then 1 part by weight of pyromellitic anhydride as a crosslinking agent with respect to 100 parts by weight of PET from which moisture has been removed in the extruder. , 3 parts by weight of calcium carbonate and 0.1 parts by weight of antioxidant, heated to 280±5° C. while mixing, melted, and then melted resin is put into the extruder, and the foaming agent is injected and foamed into a sheet. The average thickness is 2.5 mm and, about 97±1% of the total cells are closed cells, the average number of cells is 12±5 per 1 mm2, and the average size of the cells is 450±20 μm. A method of manufacturing a lightweight composite material using PP foam.

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