DE2229169A1 - PROCESS FOR THE RECOVERY OF WASTE MADE FROM RUBBER AND POLYETHYLENE WITH THE PRODUCTION OF ELASTIC SHAPED BODIES - Google Patents

Description

Process for the recovery of rubber and polyethylene waste with the production of elastic moldings

The rubber powder that is used during grinding or retreading from scrap tires, apart from its processing to regrind, only a limited area of application; The same applies to waste from polyethylene foils that cannot be re-manufactured due to adhering foreign matter can be fed; up to now there has mostly been nothing else but to incinerate such waste.

This situation is not only unsatisfactory from the point of view of environmental protection, but also means that a waste of economically valuable material; as well as the one consisting of r, ussver reinforced rubber mixtures Rubber powder as well as the waste material consisting of polyethylene foils namely represent high quality materials; one because of its excellent rubber-elastic properties and the other "in terms of strength and suppleness, all properties that are thus unused get lost.

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The present invention is therefore based on the object to show a method by which waste rubber powder and polyethylene films to elastic Pormkkörper with satisfactory physical properties can be processed.

This object is achieved by rubber powder and polyethylene waste preferably mixed in an internal mixer at elevated temperature, small amounts of rubber-like Materials and, if necessary, fillers.

The waste materials, each for itself, can be up to Contains 30 percent by weight of impurities.

If the rubber powder and the polyethylene waste material are mixed High temperatures can occur in the internal mixer, which cause partial decomposition of the rubber powder; at. At lower temperatures it is difficult to achieve homogenization within not too long mixing times. The kneader mixture obtained in this way is very brittle and tends to form cracks during calendering.

JOrι was surprisingly found that the addition of rubber-elastic materials such as natural rubber (= NK), styrene-butadiene rubber (= SBH),

Ethylene-propylene rubber (= EPM), ethylene-propylene terpolymer rubber (= EPDM),

or ethylene vinyl acetate rubber (= EVA), in small proportions eliminates all these disadvantages, d. H. homogeneous mixing within a short time at not too high kneader temperatures and a supple, calenderable! skin leads.

This invention also has the surprising advantage that that even heavily contaminated starting materials, d. H. z. B. rubber powder, which still contains tissue residues or Waste polyethylene film material,

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which gum stains still adhering

or contains finely divided foreign matter, for the production of porous bodies can be used.

The further processing of the kneader mixture is done either by calendering to form sheets or plates or it can be used as a those in technical standard articles of all kinds, such as JB. elastic Mudguards, bumpers, dirt bins, trash cans, etc. be hot-pressed. Further processing by injection molding appears to be particularly advantageous; however, can be pressed or calendered sheets also by vacuum forming. or pressureless hot forming by hand into corresponding IOrm articles be transformed.

The mechanical properties of the pressed bodies produced in this way are surprisingly favorable, as are those in the following Examples show values.

PE foil waste material and rubber powder were mixed with different amounts of EPDM rubber in a laboratory kneader at around 130 ° C. between 140 and 150 ° C pressed to form sheets. The following table shows the mixture composition and the result of the physical test:

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Mixture Mr A. B. C. D. E. PE film .100 100 100 100 100 Rubber powder 100 100 100 100 100 EPDM
(Celts 812) O 5 10 15th 40 Hosts (ühore A) '69 66 65 ' 65 62 Bruohfeotiekeit
[male / female ² ] 5.5 5.1 4.7 4.6 4.1 Elongation at break jjiQ 70 90 100 140 140 Zußvorformungareot
after 1 h at 50 jC
In advance nooh £ 15,000 J6J nloht measb. n.mossb n.meßb. 20th 24 naoh 1 h QQ Il Il Il 9 10

The breaking strength of the original film is 11.7 or 9.7 MN / m and the elongation at break is 400 or 510 $> in or, perpendicular to the roll-up direction. All compounds show a drop in breaking strength of about 5.0% , which increases with increasing rubber content; the elongation at break, on the other hand, increases with increasing rubber content.

Here, PE stands for polyethylene

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BeisOiel_2

PE film waste material and rubber dust were made with different Rubbers, as described in Example 1, mixed and pressed to form sheets; the following table shows the result the physical test .:

: iiaohunc I «" r. I * G H I · L'K-Folic j 100 100 100 100 Rubber powder 100 100 100 100 ^ iK (omokcd cheot) 10 SBIl (Jluno 1 ^ 0) 10 El ³ H (Dutriil N) 10 EVA (Lcvaju-en 450) • 10 ^ Urto (ühoro A) 85 86 84 85 8ruohfontiökeit {jMJi / mj 4.6 4.6 4.0 6.7 ßruohiiöhnunj [% J 70 70 40 170

In the case of mixture I, the tensile set could also be increased
an octane pre-elongation can be determined to 50%; he
was 24 '· /> after 15 seconds. and 10 <; £ after an hour.

The values show that the addition of the various rubbers leads to approximately the same physical values except for the very same

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2229Ί69

highly viscous EVA, which significantly increases the breaking strength and the elongation at break.

PE film waste material and rubber powder were in different Mixing ratios with EPDM rubber, as described in Example 1, mixed and pressed to form sheets; the following The table shows the result of the physical test:

Mioohung Ilr J C. K PE film
Gumini flour
EPDM
(Colten 812) 100
50
10 100
100
10 100
150
10 Härtn (ühoro A)
Breaking strength [MN / mJ
Elongation at break QQ 90
5.9
90 85
4.7
100 77
3.6
100
ι ail »ii ι '

The values show that hardness and breaking strength decrease as the proportion of rubber powder increases.

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For example £ iel_4

PE sheeting waste material and rubber powder were made with EPDM rubber and various amounts of fillers, such as ground limestone and asbestos, as described in Example 1, mixed and pressed into plates. The following table shows the result of the physical test:

Miochung Hr L. M ■ N 0 PE folio
'Jummimohl
EPpM
limestone
(meal)
Anger 100
100
, 4
40 100
= 100
40 100
100
15th
50 100
100
15th
50 Härto (Shoro Λ)
Bruchfeatiflkoit [mn / oJ
Elongation at break \ jfj 90
5.7
«50 ΘΘ
5.2
70 09
4.6
60 91
5.1
50

Mi3chung 0 from the previous example was dissolved in a 2 kg - mixed Werner & Pfleiderer kneader, and drawn on a hot roll at a Pell; this fur was

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pressed between two metal sheets on a laboratory press at 140 ° C and taken out of the press after cooling.

The plate was cut to the dimensions of a mold for a fender; this piece of plate was in a warming cabinet heated to 180 ° G and brought into the concave, also at least 120 ° 0 warm molded part of a fender shape. The plastic material immediately adapts to all details of the form; with the help of the mold cover, which is without If significant closing pressure can be applied, protruding material parts can be sheared off. After cooling down to less than 80 ° C can be demolded.

The fender obtained in this way has a perfect surface; in addition to those given in the table of example 4 physical properties the following values were also determined:

Tear resistance (DIN 53 515)

Krioohvorholten boi oinor tension from Ο, Ρ!

25.7

23 ° C 70 ⁰ C Initial deformationι 0.5 2.5 after 1 day ι 0.7 1.8 '"■ 3 Toßoni 1.0 1.9 "10 Togon * 1.5 2.5 "20 Toflcim 1.6 3.3

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As far as the cold behavior is concerned, the fender was stored in a freezer at -20 ° C; at this temperature the flexibility is still fully preserved. From the torsion module temperature curve it can be seen that the temperature,

8 MN
at which the modulus of torsion exceeds 10 ~ 2 , is in the region of -20 ° 0. Experience has shown that brittle fracture occurs below these temperatures when exposed to impact.

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Claims (7)

- ίο - Claims 1 'ancestors for producing elastic Forrnkb'rpern au α powdered rubber and polyethylene by mixing, characterized in that the mixture contains 0.5 His 20 ^v /> to not compounded rubber such as natural rubber' (= NK), styrene-butadiene Rubber (= SBR), ethylene Propylene rubber (= EPM), ethylene-propylene terpolymer rubber (= EPDM), ethylene-propylene terpolymer rubber (= EPl ¹ ) or ethylene vinyl acetate rubber (= EVA) are added. 2. The method according to claim 1, characterized in that rubber powder and polyethylene are used, each up to 30 # Contains foreign substances or fine-grained impurities. 3. The method according to claim 1 or 2, characterized in that fillers are added. 4. Process according to Claims 1 to 3, characterized in that the mixing is carried out in a kneader. 5. The method according to claim 4, characterized in that one the mixing is carried out in a laboratory kneader. 6. The method according to claims 1 to 3, characterized in that that the premix is carried out in an internal mixer. 7. Process according to Claims 1 to 6, characterized in that the polyethylene is in the form of polyethylene films begins. 309882/0748