KR20130067042A

KR20130067042A - High performance epdm foam including eco-friendly, nontoxic and fireproof characteristics and manufacturing method thereof

Info

Publication number: KR20130067042A
Application number: KR1020110133868A
Authority: KR
Inventors: 이봉직; 양기욱
Original assignee: 주식회사 익성; 이봉직
Priority date: 2011-12-13
Filing date: 2011-12-13
Publication date: 2013-06-21

Abstract

A non-toxic, flame retardant, highly functional EPDM foam and a method of manufacturing the same are disclosed. The disclosed EPDM foam has an EPDM polymer having a pattern viscosity of 40 to 80, an ethylidene norbornene (ENB) content of 8 to 12 wt%, an ethylene content of 50 to 55 wt%, and a particle size of 40 to 50 nm and an ultra high frequency. International flame retardant standard (UL94) containing carbon black, magnesium hydroxide, melamine cyanurate, and polyphosphate, composed of carbon black with a water solubility of 10 or more. It relates to a high-foam EPDM foam having a specific gravity of 0.04 to 0.1 satisfying V0 and a method of manufacturing the same.

Description

Eco-friendly non-toxic and flame retardant high functional EPDM foam and manufacturing method thereof {HIGH PERFORMANCE EPDM FOAM INCLUDING ECO-FRIENDLY, NONTOXIC AND FIREPROOF CHARACTERISTICS AND MANUFACTURING METHOD THEREOF}

The present invention relates to an environment-friendly, nontoxic / flame retardant high functional EPDM foam and a method for manufacturing the same. More specifically, it does not become flame propagation, and has a gas toxicity index of less than 0.5 and an acid flame index of 35 or more. It relates to an environment-friendly high-foaming EPDM foam having a density of 0.04 to 0.1 satisfying the V0 and a method of manufacturing the same.

EPDM foam has the advantages of being relatively inexpensive and having excellent heat insulation and heat resistance. For this reason, EPDM foam is mainly used as a heat insulating tube for building air conditioners or as a heat insulating material for construction. However, in case of EPDM foam, the flame retardancy is inferior to that of NBR foam.

In general, methods for flame retarding polymers include adding non-combustible materials, physicochemical treatment of the surface, and adding a flame retardant. Among them, a method of adding a flame retardant to a material to impart flame retardancy is the most effective method. . In order to improve the flame retardancy of EPDM, which is a non-polar polymer, it is difficult to expect a dense chemical reaction between the flame retardant and the polymer compared to a polar polymer such as NBR. Therefore, a large amount of flame retardant must be added to improve the flame retardancy. Inhibits the chemical reactivity of the additives such as crosslinking agents, foaming agents and unsaturated hydrocarbons of EPDM to lower the foaming ratio and to lower the physical properties such as compressive modulus and surface smoothness. For the same reason, it is very difficult to manufacture high foaming low specific gravity EPDM foam having excellent physical properties such as compressive modulus and specific gravity 0.04 ~ 0.1 while satisfying the VO standard of UL94.

The present inventors conducted research to solve the problems of the EPDM foam as described above, and developed an eco-friendly EPDM foam which is lighter and has better mechanical properties and improved flame retardancy compared to existing products.

Accordingly, it is an object of the present invention to provide a non-toxic eco-friendly EPDM foam and its manufacturing method.

Another object of the present invention is to provide an EPDM foam having excellent flame retardancy and a method of manufacturing the same.

Another object of the present invention is to provide a high-foaming EPDM foam having a low specific gravity and a method for producing the same.

Further, another object of the present invention is to provide an EPDM having excellent physical properties and a manufacturing method thereof.

According to the present invention, in the EPDM foam, the EPDM polymer having a pattern viscosity of 40 to 80, an ethylidene norbornene (ENB) content of 8 to 12wt%, and an ethylene content of 50 to 55wt%, and a particle size Is 40 to 50 nm, and the weight ratio of carbon black, magnesium hydroxide, melamine cyanurate, and polyphosphate having a water solubility of ultra high frequency micro wave of 10 or more is 3: It can be achieved by a combination of 3.5: 2 composite flame retardants and other additives, such as processing oils, blowing agents, crosslinking agents and vulcanizing aids.

Here, the EPDM resin is preferably 30 to 40wt% based on the total weight of the EPDM foam composition.

Here, the carbon black is preferably 25 to 35wt% based on the total weight of the EPDM foam composition.

Here, the flame retardant is preferably 8 to 15wt% based on the total weight of the EPDM foam composition.

According to the present invention, in the EPDM foam manufacturing method, the pattern viscosity is 40 to 80, the ethylidene norbornene (ENB) content of 8 to 12wt%, the ethylene content of the EPDM 50 to 55wt% Carbon black, Magnesium Hydroxide, Melamine Cyanurate, and Polyphosphate of 40 to 50 nm in polymer and particle size and ultra high frequency micro wave Kneading a composite flame retardant having a weight ratio of 3: 3.5: 2 and other additives such as processing oil, blowing agent, crosslinking agent and vulcanizing aid; Firstly extruding the kneaded EPDM foam composition: aging the extruded EPDM foam composition for a certain temperature, constant humidity, for a period of time; Secondarily extruding the aged EPDM foam composition; Passing the second extruded EPDM foam composition through an Ultra High Frequency Microwave Oven; Passing the EPDM foam composition passed through the microwave oven through a hot air oven; Cooling and cutting the EPDM foam that has passed through the hot air oven; It can also be achieved by an EPDM foam manufacturing method characterized in that it comprises.

Here, the kneading of the EPDM foam composition is added to the carbon black, processed oil, other additives after a predetermined time after a certain time after the raw material rubber to the Banbury Mixer (Banbury Mixer) and after a certain time the remainder of carbon black, processed oil, other additives It is preferable to use the two-stage kneading method which adds a crosslinking agent, a crosslinking promoter, a foaming agent, and a foaming accelerator, and finally adds 1/2.

Here, the extruder temperature of the first extrusion step is preferably 80 ° C or less.

Here, the conditions of the aging step is preferably a temperature of 20 ℃, a relative humidity of 30% and 72 hours.

Here, the extruder temperature of the second extrusion step is preferably 80 ° C or less.

The microwave oven (Ultra High Frequency Oven) is preferably such that the surface temperature of the EPDM foam composition is 100 ~ 130 ℃.

Here, the heating temperature of the hot air oven (Hot Air Oven) is preferably to be 140 ~ 180 ℃.

According to the EPDM foam and its manufacturing method configured as described above has the following effects.

First, it is possible to manufacture EPDM foam having flame retardant performance that can satisfy V0 of international flame retardant grade UL94.

Second, high foaming and low density foams with specific gravity 0.04 ~ 0.1 can be manufactured.

Third, it is possible to manufacture an eco-friendly EPDM foam having a gas toxicity index of less than 0.5, an oxygen index of 35 or more, and no formaldehyde is detected.

Fourth, high elastic EPDM foam having a compression set of 35 or less can be manufactured.

1, FLOW-CHART of the manufacturing process, which can produce the EPDM foam according to the present invention,
Figure 2 shows a schematic view of a manufacturing apparatus of an embodiment capable of producing EPDM foam according to the present invention.

Hereinafter, with reference to the accompanying drawings will be described in detail the EPDM foam and its manufacturing method according to an embodiment of the present invention.

The term EPDM used in the present specification is based on ethylene / propylene / nonconjugated diene terpolymer polymer, and the ethylene content is preferably in the range of 50 to 55 wt%. If the content of ethylene is lower than 50, the shape retention ability of the EPDM foam of the present invention is poor and smooth extrudability cannot be expected, and if it is 55 wt% or more, it acts as a factor for increasing the hardness of the foam. As the conjugated diene, dicyclopentadiene (DCPD), 1,4-hexadiene (1,4-HD), dicyclooctadiene (DCOD), ethylidene norbornene (ENB) and the like are used. The EPDM polymer used in the present invention may be a polymer EPDM polymer alone or a compound of two or more EPDMs having different properties. Since the EPDM polymer of the present invention should be capable of fast crosslinking for the preparation of high foaming foam, it is preferable to use 8-12% by weight of ethylidene-norbornene (ENB) unconjugated diene which is capable of fast crosslinking. In addition, the pattern viscosity of the EPDM polymer of the present invention (Mooney Viscosity) should have a value of 40 to 80, the reason is that if the pattern viscosity is less than 40 it is difficult to expect the fast crosslinking required in the present invention, the pattern viscosity is more than 80 If it is large, it is difficult to expect uniform kneading with other additives. In addition, the ethylene content of the EPDM polymer of the present invention is preferably 50 to 55% for smooth extrudability and shape retention of the EPDM polymer. In addition, the EPDM resin is preferably 30 to 40wt% based on the total weight of the EPDM foam composition.

As used herein, the term filler is a substance added for the purpose of anti-aging, reinforcement and extension in the practical use of rubber or plastic.

Inorganic fillers and organic fillers blended with conventional rubbers such as clay and carbon black. Examples of the carbon black include HAF carbon black, MAF carbon black, FEF carbon black, SRF carbon black, GPF carbon black, and the like, among which the particle size is 40 to 50 nm and the ultra high frequency micro wave has a water solubility of 10 to 10. Carbon black of 20 is most preferred as the filler of the present invention. Herein, the ultra high frequency micro wave acceptability may be expressed as follows by measuring the change of the surface temperature of the surface of the material at a reference time after irradiating the microwave with the material.

* (t150-t80) is the time required for the surface temperature of the material to rise from 80 ° C to 150 ° C.

Here, when the carbon black of the present invention has a water solubility of less than 10, the carbon black of the present invention rapidly reaches the temperature required for a typical initial vulcanization step in the ultra high frequency oven of the embodiment for achieving the present invention. If it is difficult to do and is larger than 20, the internal temperature control becomes difficult. In the present invention, the blending amount of the carbon black filler is preferably 25wt% to 35wt% based on the total weight of the EPDM foam.

As used herein, the term flame retardant is a substance which is added to plastics to improve the flame retardancy of plastics and may be classified into organic flame retardants such as halogen and inorganic flame retardants such as magnesium hydroxide. Halogen-based flame retardants represented by bromine series have been used in a relatively small amount compared to inorganic flame retardants. However, it has recently been regulated due to the emission of pollutants during combustion, which has led to the development of non-halogen-based flame retardants. Flame retardants that can replace halogen-based flame retardants are well known metal hydride flame retardants, nitrogen-based flame retardants and phosphorus flame retardants. However, in the case of EPDM foam resin composition, it is difficult to expect a sufficient flame retardant effect by such a conventional method. For this reason, in order to obtain sufficient flame retardancy in the case of a hydrated metal flame retardant, a large amount of 50 to 60 parts by weight relative to 100 parts by weight of EPDM polymer is required. It is not suitable because it must be added. Representative examples of nitrogen-based flame retardants include triazine-based flame retardants, that is, melamine. In the case of melamine, UL94, an international flame retardant grade, exhibits flame retardancy by preventing flame spread through the phenomenon of spark dropping during ignition. There is a fatal disadvantage that can not prevent the ignition of the bottom surface by the falling of the flame. Phosphorus-based flame retardants, which are classified as additive and reactive, are also insufficient to be applied to plastic applications because it is difficult to prevent ignition of the lower end surface caused by the above-described flame drop of UL-94. For the above reason, in order to flame retard the EPDM foam of the present invention, with the flame retardant mechanism of any one of the above-described flame retardant (Mechanism) to express the flame retardant performance of the V0 grade of UL-94, the international flame retardant standard aimed by the present invention Is impossible. Therefore, in the present invention, a composite hydrate-based flame retardant composed of magnesium hydroxide, melamine cyanurate, and polyphosphate was used. In the present invention, the blending amount of the flame retardant is preferably 8 to 15 wt% based on the total weight of the EPDM foam. If the amount of the flame retardant is less than 8wt% of the total weight of the EPDM foam, it is difficult to expect a sufficient flame retardant effect, and if it is more than 15wt%, it is easy to inhibit the basic properties of the EPDM foam, such as foaming ratio and compression modulus.

As used herein, the term plasticizer can be used for conventional rubber or thermoplastic elastomer. Examples of plasticizers include petroleum softeners such as process oils, lubricating oils and paraffinic oils, fatty oil softeners such as castor oil, linseed oil, rapeseed oil, palm oil, dibutyl phthalate, dioctyl adipate, dioctyl sebacate and the like. Ester plasticizers, hydrocarbon oligomers, and the like. In EPDM foams, the lower the viscosity of the processed oil, the better the dispersibility and the extrudability of the compound. However, excessively low viscosity process oils can reduce the viscosity of EPDM foams and increase scorch time, which can inhibit the foaming properties of EPDM foams and reduce the mechanical properties of the foams. In addition, when the EPDM foam is exposed to room temperature for a long time, the processing oil may gradually come out to have the hard properties of the EPDM foam. Conversely, high viscosity process oils can increase the viscosity of the compound, reduce the mechanical properties and scorch time of the foam, but can impair the dispersibility of the additives, make the surface of the compound unsmooth during extrusion, and increase the load on the extruder. have.

As a preferable process oil of this invention, it is preferable that it is the medium molecular weight whose kinematic viscosity is 40-60 and Mw = 300-400.

Stearic acid used in the present specification forms a complex compound or a metal salt with a metal oxide (zinc oxide) to increase the compatibility with rubber and at the same time serves to easily activate the vulcanization accelerator in the crosslinking active agent. The stearic acid is preferably used in 1 to 3 parts by weight, when less than 1wt% relative to the total weight of the EPDM foam composition, the amount of metal complex formation may be small, there may be a problem in lowering the activation of the antagonist in the crosslinking agent, 3wt When the amount exceeds the metal salt is formed in excess, the activation of the vulcanization accelerator in the crosslinking activator is increased and the workability is increased by lowering the viscosity, but there may be a problem in that physical properties such as tensile strength, sinterability, compressive permanent shrinkage decrease.

Zinc oxide, as used herein, forms a complex with stearic acid present in the formulation to enhance the activity of the vulcanization accelerator in the crosslinking activator. The “zinc oxide” is preferably used in an amount of 3 to 7 wt% based on the total weight of the EPDM foam composition. When the amount is less than 3 wt%, the amount of metal complexes is small, which may cause a problem of lowering the activity of the vulcanization accelerator in the crosslinking activator, 7 wt. If the amount exceeds the metal salt is formed in excess, the activation of the vulcanization accelerator in the cross-linking activator is increased and the workability is increased by lowering the viscosity, but there may be a problem that the physical properties such as tensile strength, aging properties, compressive permanent shrinkage.

As used herein, the "crosslinking agent" and "crosslinking active agent" to crosslinking between the main chain by crosslinking the EPDM polymer to enhance the properties such as higher mechanical properties, a mixture of sulfur and vulcanization accelerator, Mixtures of phenolic resins and halogen donors, mixtures of peroxides and peroxide activators, and the like can be used. For example, sulfur and the vulcanization accelerator preferably use 1.2 to 2.0 wt% of sulfur and 0.5 to 4.5 wt% of the vulcanization accelerator, based on the total weight of the EPDM foam composition. If there is a deviation from the upper limit, it becomes too hard due to excessive crosslinking, and there may be a problem that adversely affects physical properties due to the remaining of the unreacted crosslinking activator.

Hereinafter, an embodiment of a sound absorbing material manufacturing apparatus capable of manufacturing the EPDM foam according to the present invention will be described with reference to FIG.

Sound absorbing material manufacturing apparatus according to the first embodiment, a kneading machine (1) for kneading the EPDM foam composition of the present invention as shown in FIG. A primary extruder 2 for primary extrusion of the kneaded composition; A second extruder 4 for kneading and extruding the aged EPDM foam composition once again before vulcanizing foaming; Ultra High Frequency Microwave Oven (5) for heating and vulcanizing and prefoaming the second extruded EPDM foam composition; A hot air oven (6) for heating the EPDM foam composition passed through the microwave oven (6); and a cooler (7) for cooling the EPDM foam of the present invention crosslinked and foamed through the processing; Cutting machine (8) for cutting the cooled EPDM foam to a certain size; EPDM foam of the present invention is manufactured using an EPDM foam manufacturing apparatus comprising a.

Hereinafter, after manufacturing the EPDM foam in a total of four cases by the method of the present invention described above, compared with the EPDM foam of Comparative Examples 1 and 3 to be compared, the specific gravity of the EPDM foam, permanent compression line The sound rate, flame propagation, and oxygen index test results will be described.

&Lt; Example 1 >

The manufacturing method of the product of Example 1 was performed according to the process sequence of FIG.

KEP 370F, an EPDM product of Kumho Polychem Co., Ltd., whose pattern viscosity is 69, 59 wt% of ethylene, and 8.1 wt% of ethylidene-norbornene (ENB), has a pattern viscosity of 77, an ethylene content of 54, and ethylidene-norbornene (ENB) After introducing Keltan 7350A, an EPDM product of LANXESS with a content of 9.7wt%, in a ratio of 2: 8, a test balm that rotates 50 times per minute to be controlled at an internal temperature of 80 ° C with a capacity of 10L and a coolant (Banbury) ) It was Soviet for 30 seconds after being put into kneader (1). after

80 parts by weight of FEF carbon black having an average particle size of 40 nm and a water solubility of 11.09 and 70 parts by weight of paraffin oil having a specific gravity of 0.89 and designed by the present invention. 30 parts by weight of a composite flame retardant mixed with magnesium hydroxide, melamine cyanurate and polyphosphate in a ratio of 3: 3.5: 3.5, 5 parts by weight of zinc oxide and stearic acid 1/2 of 1 part by weight was added first and kneaded for 1 minute. After 1 minute, 1/2 of the additive was added and kneading was performed under pressure for 3 minutes. Thereafter, 1.5 parts by weight of sulfur crosslinking agent, 10 parts by weight of foaming agent (Gumyang, ACP / W), 1 part by weight of foaming aid (Gumyang, CELLEX-A) and 1.5 parts by weight of vulcanization accelerator (Zinc di-n-butyl dithiocarbamate) 1.5 parts by weight of the accelerator M (Mercaptobenzothiazole) and 1 part by weight of the vulcanization accelerator TL (Mercaptobenzothiazole) and 1 part by weight of the vulcanization accelerator TRA (Dipentamethylene thiuram disulfide) were added and kneaded for an additional 1 minute. The kneaded EPDM foam composition was extruded using a primary extruder 2 having a diameter of 80 mm and an L / D of 10: 1. The temperature of the extruder was set to 80 ° C. and the screw 2b was rotated 30 times per minute.

The first extruded EPDM compound was put into a thermo-hygrostat (3) set at a temperature of 20 ° C. and 30% humidity for 3 days, and then the aged EPDM foam composition was 80 mm in diameter and a L / D 10: 1 secondary extruder. 2 was extruded using. The temperature of the extruder was set to 80 ° C. and rotated 30 times per minute. The extruded EPDM compound was passed through a Ultra High Frequency Microwave Oven (5) with two heating zones (2 meters long and 10 meters wide) for crosslinking and foaming. In the first heating zone (5a) of the oven, EPDM foam It heated for 7 minutes so that the surface temperature of the resin composition might become 110 degreeC. In the second heating zone 5b in the oven, the EPDM foam resin composition was heated for 8 minutes so that the surface temperature was 130 ° C. A hot air oven 6 having two heating zones in which the vulcanized and pre-foamed EPDM foam composition is continuously placed in the microwave oven while passing through the two heating zones 5a and 5b of the microwave oven. Passed. The first heating zone 6a of the Hot Air Oven 6 was set to 180 ° C. to pass the EPDM foam composition for 8 minutes and the second heating zone 6b set to 150 ° C. for 7 minutes. . In order to cool the EPDM foam of the present invention crosslinked and foamed through the above process, an air-cooled cooler 7 was passed for 1 minute. Thereafter, the finished EPDM foam was cut with a cutting machine (8) to complete an EPDM foam having a height of 30 mm (height) x 1,000 mm (width) x 1,000 mm (length).

EPDM foam was prepared by changing the amount of flame retardant to 25 parts by weight under the same conditions as in Example 1.

EPDM foam was prepared by changing the amount of flame retardant to 35 parts by weight under the same conditions as in Example 1.

EPDM foam was prepared by changing the amount of flame retardant to 40 parts by weight under the same conditions as in Example 1.

&Lt; Comparative Example 1 &

Under the same conditions as in Example 1, the composition of the flame retardant was changed to a composite flame retardant mixed with magnesium hydroxide (Extended Graphite) and expandable graphite (Extended Graphite) in a ratio of 5: 5 to prepare EPDM foam.

Comparative Example 2

EPDM foam was prepared by changing the composition of the flame retardant under the same conditions as in Example 1 to a composite flame retardant mixed with magnesium hydroxide (Extended Graphite) in a ratio of 3: 7.

&Lt; Comparative Example 3 &

The composition of the flame retardant under the same conditions as in Example 1 was changed to a composite flame retardant mixed with magnesium hydroxide, melamine cyanurate, and polyphosphate in a ratio of 5: 2.5: 2.5 to EPDM. Foam was prepared.

[Table 1] [Table 2] below summarizes the test results of the Examples / Comparative Examples of Examples 1 and 4 and Comparative Examples 1 and 3 described above.

The specific gravity of EPDM foams in Tables 1 and 2 was tested according to KS M ISO 7214 and the oxygen index was tested according to the ignition method A method of ISO 4589-2. Flame propagation test was followed by UL94 HB test and permanent compression rate was tested by KS M 6670 method. International flame retardant grades were tested to UL94 standards.

As shown in the experimental results [Table 1], an example including a composite flame retardant in which magnesium hydroxide, melamine cyanurate, and polyphosphate were mixed at a ratio of 3: 3.5: 3.5. Comparative Examples 1 and 2, where the EPDM foam of Example 1 and Example 4 is a combination of magnesium hydroxide and expanded graphite, and magnesium hydroxide and melamine cyanurate Cyanurate) and polyphosphate (Polyphosphate) can be confirmed that the flame propagation and oxygen index excellent compared to the case of Comparative Example 3 using a composite flame retardant mixed in a ratio of 5: 2.5: 2.5. In order to satisfy the V0 criterion of UL-94, which the present invention intends to express, flame propagation must satisfy the level of 0. In the case of a composite flame retardant of a similar level outside the composition of the present invention, it is confirmed that the flame dissatisfaction is in terms of flame propagation. Can be.

Examples 1 and 4 are 25 parts by weight of the composite flame retardant of magnesium hydroxide (Magnesium Hydroxide), melamine cyanurate and polyphosphate in the ratio of 3: 3.5: 3.5 And 5 parts by weight to 40 parts by weight, the oxygen index, permanent compression rate, UL-94 and flame propagation changes were observed in [Table 2] the results are summarized. In both Examples 1 and 4, satisfactory results of flame propagation and oxygen index measurements were obtained, but when the composite flame retardant was 40 parts by weight, it was confirmed that the results were lower than those of other examples in terms of permanent compression reduction and specific gravity. Can be. In the case of Example 2, it can be seen that the flame propagation and falling in terms of UL-94 compared with Examples 1, 3 and 4. The test results show that the composition and dosage of the composite flame retardant of the present invention are not merely numerical values but are necessary and sufficient conditions for expressing the performance of the EPDM foam of the present invention.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. Accordingly, the true scope of protection of the present invention should be determined by the technical idea of the invention described in the following claims.

1: kneader 1a: loader inside kneader
1b: barrel 2: kneader inside the kneader
2a: primary extruder hopper 2b: primary extruder screw
3: aging machine (constant temperature and humidity device) 4: secondary extruder
5: microwave oven 5a: chamber 1 of microwave oven
5b: chamber 2 6: microwave oven in microwave oven
6a: chamber 1 of hot air oven 6b: chamber 2 of hot air oven
7: cooler 8: cutting machine

Claims

An EPDM foam comprising: EPDM polymer having a pattern viscosity of 40 and 80, an ethylidene norbornene (ENB) content of 8 to 12 wt%, and an ethylene content of 50 to 55% or less; A carbon black filler having a particle size of 40 to 50 nm and a water solubility of Ultra high frequency micro wave of 10 phases; A composite flame retardant composed of magnesium hydroxide, melamine cyanurate, and polyphosphate; EPDM foam composition comprising a processing oil, a surfactant, a crosslinking agent, a crosslinking accelerator, a crosslinking aid, a foaming agent, a foaming accelerator.

The EPDM foam composition according to claim 1, wherein the composite flame retardant is 30 wt% magnesium hydroxide, 35 wt% melamine cyanurate and 35 wt% polyphosphate.

The EPDM foam composition of claim 1, wherein the content of the EPDM polymer is 30 to 40 wt% based on the total weight of the EPDM foam composition; The content of carbon black is 25 to 35 wt%; EPDM foam composition, characterized in that the content of the composite flame retardant is 8 to 15wt%.

The method of claim 1, wherein the kneading machine kneading the EPDM polymer and the composite flame retardant, carbon black and other additives in a two-stage kneading method:
First extruding the kneaded EPDM foam resin composition through a single extruder:
Aging the first extruded EPDM foam resin composition in a aging machine;
Secondly extruding the aged EPDM resin composition through a single extruder:
Passing the extruded EPDM foam resin composition through a microwave oven for vulcanization and prefoaming:
A step of foaming and foaming aging by passing the EPDM foam resin composition passed through the microwave oven through a hot air oven:
Cooling and cutting the foam matured EPDM foam in the hot air oven; EPDM foam manufacturing method comprising a.

The EPDM foam composition according to claim 1, wherein the EPDM foam composition satisfies the V0 standard of UL-94.