DE1989202U - NET-STRUCTURED POLYMER BODY. - Google Patents

Description

Scott Paper Company

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^: Network of structured polymer bodies «= ^

The innovation "refers to a network-structured: Polymer body made at least partially from polyolefins consists. . . ".." ■

The body according to the innovation consists of either one network-structured polyurethane polymer core ^ which is completely and intimately covered by an outer shell made of polyolefin: such as polyethylene or polypropylene, or made of polyolefin alone. In the latter case the polyuret was used hank away. The new body according to rungs "is characterized by the fact that it is practically membrane-free.

The previously known foams with a perfect network structure consist practically only of polyurethanes, but recently polyvinyl chloride foams of acceptable permeability have also been obtained in a network-structured form using a new type of explosion process. : ^; V. ^r . ■■; -, - ■:

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The term "network-structured" is a well-known technical term in the field of foam technology and identifies a grid-like product of nodes and spaced point-like to form a coherent structure connected ribs. In general, either an open-cell type is required as a preliminary stage for the formation of the network structure Formation (with communicating cells) that is given a network structure on explosive or chemical VJeg can, or a structure in which the cell walls can be removed by partial chemical attack. But also in the latter case, an open-cell structure is expedient, while it is suitable for secondary structure formation Explosion is essential so that the gas can penetrate the inside of the body.

Polyurethane structures have the disadvantage of poor acid and alkali resistance and undesirable swelling by most organic solvents. Polyvinyl chloride foams, on the other hand, can be related to Pore volume and uniformity difficult to control produce.

Most polyolefin foams, i.e. those made from polyethylene or polypropylene, have closed cells, i.e. practically no internal passages and can be

r \

consequently do not network structure in an explosive way.

However, since it is known that polyolefins are highly acid and alkali-resistant on the one hand and swell-proof against solvents on the other hand, network-structured polyolefin bodies for acid and alkali filtration have been sought for a long time, and there have been many attempts to produce such bodies. For example, polyethylene in the form of chips or fibers has already been combined to form a filter element. Other known attempts consisted in the sintering of polyethylene particles into frit filters. Although.-Polyolefin foams have already been produced, with their shred structure, which is currently still to be regarded as impossible, the pore size control in _: the areas required for filtration purposes could practically not be carried out, whereas this was practically impossible with polyurethane ': ■' .- .- Foams is quite possible. The innovation now creates suitable network-structured polyolefin bodies for acid and alkali filtration, which thus have the desired essential properties of a network-structured polyolefin foam, namely on the one hand the desirable pore size characteristics of polyurethane polymers and on the other hand the chemical resistance of the polyolefin material.

In general, there are network-structured polyurethane bodies and correspondingly produced composite structures, as already mentioned, from spaced nodes. ' united hips, creating dodecahedra with approximately pentagonal surfaces, practically free of membrane material. Of course, this description of the structure is somewhat idealized and the actual products have something dodecahedron building units that differ from one another.

Although the individual cells are randomly oriented and close to one another are anisotropic, the overall structure behaves roughly like an isotropic body. This foam property is desirable because the pressure drop characteristic is more favorable than that of the known filter plates. Because of their uniform-shaped Pore size and more isotropic nature compared to the known anisotropic filter and contact media as a result, in the form of polyethylene mats Bodies made from the new composite materials are particularly suitable for acid and alkali filtration purposes.

In addition, the bodies according to the innovation show improved Properties relating to the stress-deformation ratio. For example, the energy required for compression is essential for polyethylene-coated polyurethane higher than with uncoated polyurethane, this property

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finds "good application in a self-supporting filter.

Corresponding surprising results will be at the Märine achieved deformation of the composite body according to the innovation to any desired shaped bodies. If the network-structured Polyethylene ~ polyurethane body heated in. is held in the desired shape and then cooled, he ■ you hold a de.form-resistant body that is not like polyurethane goes back to its original form alone. This property of the body according to the innovation enables production various dimensionally stable articles with outlines difficult to mold. -

In addition, the body ^{according to the invention can be easily bonded to various other materials, 1} since molten polyethylene has good adhesiveness. Thus, for example, composite filters with different pore sizes can be produced in such a way that, in the case of a body according to the innovation, the polyethylene is melted on the surface and the body is then combined with a second, narrow-pore body of the type according to the innovation. Obviously, a wide variety of composite bodies can be produced in this way. In a similar way, the bodies according to the innovation can also be connected to any other surfaces that have sufficient adhesion to

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compared to molten polyethylene *. ■.

During the heat deformation of normal polyurethane foams there is a noticeable compression of the original structure and associated therewith a noticeable impairment of the pressure drop characteristic of the molded article. There are Many attempts have already been made to avoid this compaction, with certain very cumbersome 'procedures also already a partial solution of this deformation problem j§t * -_ have gebsm, however, the results lagged behind what is desired, back. For example, a less than satisfactory attempt at a solution has been to use polyurethane sheets and pour them before a critical expiration Time to deform and harden. All of these difficulties can now through Märme deformation of the hiring-according Polyethylene-polyurethane composite bodies are avoided.

The body according to the innovation is also suitable for use. ^: in heating system filters, humidifiers and evaporative cooler plates (whereby surface modifiers such as glass, asbestos, feldspar or pumice can be used in connection with this). For example, by using polyurethane as a carrier and an adhesive for the deposition, various types of fine particle material or powder on him, which from the already mentioned-

% ■■■■■ _ -7-

Materials or others, such as clay, carborundum and the like, may consist of novel, surface-modified ·. manufacture te bodies.

With the help of the body, many can become involved in polyurethane occurring problems of the filtration ,. Solve shaping and other types, in which the network-structured polyurethane with one of this polyurethane structure, resembling ..'-.

■ .- - ■■■■■ '.-;"" - · _-: is provided from polyolefin covering, can furthermore be compressed to ⁷ renewal proper body objects of good porosity and permeability examples still good structural strength produced. For example, compressions in a ratio of 2 to 15 to the initial volume were achieved. ;

Regarding suitable processes for the production of the new. erungsgemäßen body is to say the following: A _geeigne-: th process is that a polyurethane body V moistened preferably with water, powdery on the moist body polyolefin, eg polyethylene or polypropylene. ■ or their copolymers, deposited in a distributed manner and then the polyolefin powder is burned in situ by the water-moist and powder-covered polyurethane body, for example by placing it in an oven or

■ '-, .. radiation- ■ heating zone using infrared, or transfer heat is subjected to a heat treatment: and

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this sequence of steps of moistening, dusting - and heating - is repeated if necessary. Depending on the pore size of the polyurethane, urethane body and the particle size of the polyolefin powder; additional polyolefin powder quantities can be applied in the first two steps. The increase in weight can be up to 700% when this process is repeated, depending on the pore size of the polyurethane foam and the grain size of the polyolefin powder. This number will be explained in more detail later With regard to the heat treatment step, it is important that _: until they decompose (at around 230 0), polyurethane foams can withstand considerably higher temperatures than polyolefins and even higher temperatures for a short time. ...; - _.:

As mentioned, the new structure according to the general structure has the same structural form as the polyurethane. the physical appearance of the end product therefore depends on the foam used. In general, the pore size of the polyurethane foam is between 2 and 2k, preferably between 2 and 18 pores / cm, and most preferably between ^ and 10 pores / cm.

In general, polyurethane foams are the reaction product from a polymeric polyol resin and a polyisocyanate, taking these components in the presence of mass Release of blowing gas and / or one by the heat of reaction

activated blowing agents are implemented, while the Polymer was in a firmer, but still malleable state. Most common foams contain -a - "'. Polyester or polyether resin as reaction component. Reticulated foams of the above type are supplied by Scott Paper Company, Foam. Division, Eddystone, Pennsylvania. -

Polyolefins suitable for the production of the body according to the innovation contain ethylene, propylene, 1-butene (and its isomers) or mixtures thereof as monomer components. Their suitability depends on the fact that their melting point is below the decomposition temperature of the polyurethane. .. To certain advantageous properties, such as. Load tolerance. Depending on the heat resistance of the substrate, the melting temperature of the coating material should not be above 232 G. In the suitable method for producing the body according to the innovation indicated above, high temperatures above 232 are also possible if the exposure time is only short ⁰ G. However, the temperature should preferably be below 232 ⁰ G and best below 215 G ..::. -. V

Polyolefin powders are available from a number of manufacturers, e.g., U.S. Industrial Chemical Co., New York,

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UJ, polyethylene powder with grain sizes corresponding to 2 0.125 mm. Mesh size, densities between 0, -912: and 0.950 ^ and above and melting index numbers from 1 to 1 ^ 0. Polyethylene and ethylene copolymers are also available from Dow Chemical Co., Midland, Mich., And Union Carbide:. -. "■ Plastics Co., New York, N.T. , available. The latter supplies polyethylenes in various up to the highest densities "Grindable form the Heisler Corporation, Wilmington," Delaware, "and the Liquid Nitrogen Processing Corporation, Malvern, Pennsylvania. Other polyethylene powders with grain sizes corresponding to 2-0.080 mm mesh size, as well as polyethylene of higher, i.e. about 0.95 and preferably even higher Density are also available. When using the polyolefins listed above, it must be ensured that their melting and pouring point does not exceed the decomposition temperature of the polyurethanes used ..

The following data shows the results of a pressure drop test " in the case of an uncoated or polyethylene-coated one Polyurethane of ^ i- pores / cm pore size.

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Table 1 .- - Pressure drop test with uncoated resp.

coated polyurethane

Coating mass in %, pressure drop , 4 V in

based on polyurethane foam

sample

cm mass column in water with a flow velocity from 1O6 rn / min

Control experiment -im-coated polyurathane foam 10 pores / cm - 2.5 cm thick

according to the renewal body 10 pores / cm - 2.5 cm thick

150

1,87.5

The above results show that the more rounded Cross-sections of the coated ribs show less air resistance than the concave-triangular in the case of the control sample cause. In general, as the amount of polyolefin increases, the pressure drop increases very little, and solids with up to three times the amount of polyolefin in relation to poly, urethane show only a slightly higher pressure drop.

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Table 2 . . -. . .. ■ /

Pressure drop values of compressed polyethylene-polyurethane foams with 6 pores / cm -

S flow

speed

m / minute

Pressure drop Δ P in cm at a given VJase flow velocity .. ',

1.25 cm thick poly- from 1.27 to 0.45 cm ethylene-polyurethane-compressed foam material -

60.9
76, line

106.6

121.9
137.1

165.1
182.8

0.03 0.05 0.0? 0.12 0.15 ■ Q-, 20 0.25 0.31 0.38 0.44

0.10 0.15 0.20 0.30 0.38 0.48 0.58 0.71 0.86 1.01

Show different degrees of compression of the foams different pressure drop values and therefore obvious a special feature of the body according to the innovation, namely the possibility of pressure drop regulation with the aid of compression. As described above, it has polyurethane - .. body ^ after ~ the polyolefin powder is first sintered on and then has flowed around the polyurethane body, a core made of polyurethane and an intimately enveloping polyolefin

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MlIe. The tilting of the network-structured according to the innovation Bodies generally have an elliptical cross-section and are not like polyurethane foam concave profile. ..: '■■.' . - .- .. "." ".- ■" "

In order to produce a body consisting essentially of polyolefin, the polyurethane core must have been hydrolytically removed from the polyolefin. Polyurethane foams with insufficient curing: or a Pply isocyanate index that is too low, ie below 100% stoichiometrically, is particularly well suited due to more effective hydrolysis. The pore sizes of the polyurethanes are about the same as those above for the polyolefin structures. -. specified.Foams of low density offer correspondingly less mass to be attacked by strong hydrolyzing agents. The hydrolysis is carried out by simply soaking the foam with a solution that hydrolyzes the polyurethane or its ribs or nodes in the desired strength of the finished product appropriate intervals, is cut and in a highly hydrolyzed solution of eg * strong acid οder liquor having: _upstream,:: is preferably maintained at an elevated .Temperature and high concentration, wherein the polyurethane core dissolves in principle suitable for this purpose each HydrοIysiermittel. but acids such as sulfur acid, hydrochloric acid or phosphoric acid are "preferred". It can also be used with weak ones

Acids worked xf he, however, this requires unconditionally long treatment times. Instead of acids are also strong bases such as sodium, potassium or lithium hydroxide as well as their salts with weak acids can be used. The same applies to the salts of weak bases with strong acids. In all cases the polyurethane becomes hydrolytic degraded, although other unknown factors, such as in the. \ _ Precipitation of concentrated sulfuric acid, perhaps oxidation, -Sn be considered. ".- ..

In general, the polyurethanes are preferably made of polyester-polyurethanes, but other polyol materials are also possible, like polyether, possible if a longer one Treatment time is sustainable. "V

: Instead of the polyurethane-polyolefin body to facilitate, to cut the introduction of the hydrolyzing agent, can also use the polyolefin powder until it becomes liquid.

^{: be} heated, the hips and nodes of the poly-; urethane body is only partially covered. In this way, only part of the polyurethane surface is subjected to hydrolytic degradation if treated correctly. A body preserved in this way falls: It was also in the area of the innovation, but because of the tendency of the polyethylene to split up into individual cells, it is more firm ^ but differently.

on the one hand because of its considerably larger surface for special uses of hats. . . "

Besides these two "methods of introducing the hydrolyzing agent." In the polyurethane structure, it is also possible to assume that the material is cut up - that which is exposed Has edges (unless there is a subsequent coating treatment learned), and treat it with an over-strength hydrolyzing agent, such as sulfuric acid, long enough; So where the treatment time does not matter, you can also remove the polyurethane in this way. This procedure is generally suitable for small-sized pieces. Also, if there is an impurity of the filtrate flow is irrelevant, the complete structure can be used, whereby after some time the: Polyolefin skeleton remains. . -

If the polyurethane-forming raw material is polyolefin

powder are added, then the received innovation Polyolefin body; a considerably thinner core. In general, the hollow-core products are called such used. However, if a hollow core is not desired, such a body can be subjected to an esplosive flame front be, but for 'a protection against melting or burning the body-taken care of. ■■ - ..; ._; ■

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Example 1 . '■ ". ■"

One. 15 χ 15 x 2.5 cm sample of "Scott Industrial" foam with U> pores / cm, was mixed with polyethylene powder (Miörothene 7 ^ 0, from UvS. Industrial Chemicals Company, Koim size accordingly. 0.30 mm mesh size, pain index 22, density 0.916 coated) in the manner they first moistened with water, the powder danach'mit dusty, dried, and finally for 10 minutes in an oven at 18O -geschmolzen ⁰ C. The polyethylene cover was $ 229 of the polyurethane weight. In the same manner, coatings of $ 190, $ 269, and 31QJi polyethylene were obtained. ...

Example 2 :. . . - .- '. . ■

Polyethylene-coated polyester-polyurethane foam (with polyethylene glycol adipate as an ester component). with \ k pores / cm, its chemical resistance depending on the grain size of the polyethylene powder used (with melt index 22 and density 0.916) or, in the case of the powder with a grain size corresponding to 0.105 mm mesh width with Schmelziidex-5 and density 0.92 ^ - examined. The results are given in the table below »

Table 3

Effect of particle size on the chemical " strength .-

Grain size
speaking
short distance un-
Ma-
in Relatives s
Olefin-in
Weight fo be Weight s ver
lust for poly
urethane 2 hours. at 6O ⁰ C - .- Ä pulled up
Polyurethane - 21% HCl V 7 Oi i HoSO ₁ . MaOH 0.84 406 100 100 39 0.50 3 ^ 3 42 "... 93 '"21 0.30 281 28 49 5 , 4 0.177 210 2.5 83 0 0.105 180 41 72 2 ,8th .

The data show that despite the strong coating by the coarse-grained resin substance has the highest chemical resistance with this type of polyethylene in the grain size range between 0.30 and 0.177 mfli mesh size is achieved. Further experiments showed that variations in the melt index of the polyethylene have only a minor influence on the chemical resistance » Despite their proven acid resistance These structures can still be used for other purposes such as form or Profiling and. the like can be used *:; :

: Example 3 ■ ..:

The _: Dependency between ¹ polyethylene resin cover and "."

Chemical resistance was studied on a mixture of 5% polyethylene powder (grain size corresponding to 0.105 mm mesh size and melt index 5) and 75% polyethylene powder (grain size corresponding to 0.30 mm and melt index 22). Coated polyurethane foam had the same properties as in Example 2. The values given in Table k below were obtained by immersing a cut sample in acid. Even better values than those given were obtained by additionally covering the cut edges, purposefully covering the polyurethane core against attack by acid.

Table V

Effect of the plastic absorption on the chemical

.strength '.

Applied polyethylene weight loss of the poly

resin (in wt.% of poly-urethane in%

urethane . In ZIj -HCl, 2h · at 6.0 ° G

265-19

295 16

■: .. ■ '2.5

The fine-grained (0.105 "i Mesh size) polyolefin always a perfect coating without .visible "drying oil". under the microscope, however.

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if this is thinner than with coarser polyethylene particles, the use of a mixture of 25% polyolefin powder,. "With a grain size corresponding to 0, 105 mm mass width and. 75% of a coarser polyolefin powder resulted not only in a better coating, but also in increased resin absorption."

; Example, 4 """..- ■ / ■". , -. "■■

Foam with. the properties given in example 2 was coated with the polyethylene described in Example 3. polyethylene grain size and polyurethane water intake were varied. .

V / Table 5 "■ 'Λ ν ". Influence of water absorption and resin grain size on resin absorption

Grain size V- ¥ a, s se would take resin uptake in mm in % / of the polyurethane, in % of the poly-

'\ - · '---'-'. ■ V urethans: ■ ^: -

.0 ^ 04 V33 ■ '-: ■■■■ - V V 200:

0.84 - / / 58 V 265 ^:

0.84. ',;. ; V 82 304 V

0.84 107; :. '■■ ^: M§ //.

0.50 / ./■: 25 ν. 195 /

0.50:;. ■; /. ■. 50; ^: ; 254

■ 0.50 V .75. '. "■ 273 /; / ... -: ■

0.50 100 v / '-'. V 278

0.30 25 186

0.30 50 223

0.30. ■ --.-. 75 221

0.30 100 250

0.177 25 ..-. ■ .. - 119

0.177 50 136

0.177 75 ^;; 156

0.177 100 197

0.105 ■. ■. · 25 ■ '.... .77

0.105 50. 105

0.105 75 9 ^

0.105 100 9k

These figures show that resin uptake increases with increasing grain size. It should be noted, however, that when using grain (ζ. B. corresponding to 0.8 ^ mm mass width) the chemical resistance even with high resin. absorption decreases, while the physical properties, such as pressure load deformation, improve noticeably. Experiments carried out analogously with a fine-pored:; (10 pores / cm) polyurethane and a polyethylene (grain size corresponding to 0.177 mm mesh size, melt index 22, density 0.916) resulted in 217 ^ resin absorption and those with coarser-pore (^ i-pores / cm) polyurethane with melted polyethylene (melt index 9, density of 0.950) gave 150 ^ resin uptake.

Example 5

by means of -. ■ .... One by explosive decomposition / an acetylene-oxygen mixture network structured. Polyurethane foam "has a glassy surface that does not match applied polyethylene interacts, rather leads. " a lapping of the coated foam causes it to get rid of and, in the case of a thin covering area, even to a peeling of the resin. "...: .....

The physical properties of the bodies according to the innovation differ surprisingly from those of the poly; urethane material, for example the hips of the net-structured body according to the invention have an elliptical cross-section with, for example, a foam sample with k pores / cm and 26.7 $ resin absorption on average 0.31 mm long and 0.4? mm short axis »In the case of uncoated polyurethane foam, on the other hand, the ribs have a cross-section in the form of an approximately equilateral, ¹ concave triangle. _:

The rigidity of the structures according to the innovation is part of the proζentu- .-. alen resin uptake in a linear relationship. An adipic acid polyester polyurethane foam (^ pore / cm), ^{r is} the with polyethylene (melt index 22 ', grain size _according} ö 30 mm ^/: Maschenweite- ,: density; 0.916) is coated ^. , shows the following "stiffness values. ■ ■ ' - ~'" ~ ^x ~ '~:'".'.-;^{:; τ} " ^ΤΓ ".'^;

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Table 6

Stiffness factor of Polyathylen-PolyuFethan- Composite structures Ha rζ take up Stiffness factor (in grams). 0% 20th 10.0 Ji 90 $ 200 • 140 300 $ ' 200 370 $ ■■. ■■ - ■ 240:

The rigidity factor is that GeWiC] It ₁ that is required to bend a piece of polyfoam with a square inch cross-sectional area that protrudes 19 cm over the edge of a 15 cm high block "to the point where it meets the Horizontal forms an angle of '53 . Since, at, all weights are placed on top of the block and within 25.4 mm of the free-standing end.

■■ ''. '■ Table 7: /.

. Influence of resin absorption between I90 'Vuad 3IO wt f ₀ on the physical properties of the la ^ uerungsgemäBen Polyäthy-:

len-polyurethane composite structure at 24 ⁰ C- ^{; ;} (Polyäthylenau ^ ngsmaterial has 22 melt index, 0.30 mm: Korngroßey Fichte 0.916) ---- ''_{.;;: -:} -. '; ■■ -...

/ ■ Adipic acid polyethylene on a mesh structure

polyester-poly ~ doored polyurethane foam

'.-. ■. ". Urethane foam; with 2 ^ 5 pores / cm _:

■ '.:: "(4 pores / cm) _; / 19Q ^ ··, .. ... 269 ^

Tensile strength. 1 ^ 05 +: 30 ^ - .; --2f34 ^; "2, -49: ^ ^: 29 ^ 2 _r 54 ± '5 $>.';

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Modulus of elasticity: Q, 5O6 + "25Ji 8.23 8.75 + 2 ¥ 11.75 ± 9% under tensile load
kg / cm

2
Elongation kg / cm 228 + $ 28 98 420 120 ■ + $ 31 96 + 12 Tear resistance 0.9 ^ 3 + $ 28 2 ,: , 2 2.527 + 2 ^ 2.54+ 15 Remaining Ver
forming at 70
in fo 19.2 29 if-71 37.3 + 10 ^ $ 27.3 + $ 3 Compression energy 0.012 0, 0.823. · 1.20

Absorption at a

0.8 "/ l" deformation .. ■ -.-. :
calculated in kg / cm -;

from the pressure load _:. - _:

Deformation curve

Shock absorption in cm 2.53 13.97 25.3 - 25.3

As a measure of the shock-absorbing capacity of a foam
is the height of fall of a 1.8 kg ball, which is necessary to break the 1.6 mm thick microscope slide glass directly underneath with the blow transmitted by a 2.5 cm thick foam sample, p The ball consists of a 30g polyethylene hollow body made of material with a melt index of 3, the density. 0.9-93 and a grain size corresponding to 0.30 mm mesh size of 8 _? 9 cm outer diameter, which is filled with - ¥ ood's alloy to a final weight of 1.8 kg. A polyvinyl tile cemented into reinforced concrete serves as a base for the object glass ^ Die 7 _S 5 x 2.5 cm
Slides are supplied by the Arthur H »Thomas Company,
Philadelphia, Pennsylvania, under delivery number 7030..

^: "- ^: -24- - - - '. ■■ ■■■■■ \ -' ^:. ■■; ■: ': ■ [-

■ Special Bed Label Micro Slides supplied.

Table 8. ■. ■.

¥ resin pickup MPACT on the compressive stress-Verfors mungs-Eigens.chaften a 2.5 cm thick sample from 4 pores / cm aufweisendem polyethylene-polyurethane composite body at 24 ⁰ C (The Polyäthylenausgangsmaterial had melt index 22 ^{^:} particle size corresponding to 0,30 mm Mesh size and density 0.916)

Upset
Coating materials
based on the
P οIyure thangewi ch _irijE5i Applied pressure in kg $ 50 through
■ - bend ς / cm 0 $ 25 By «
it - bend . 0.042 - 75fi through
bend 100 0.028 0.210 0.098 ... 200 0.140 0.492 - 0.527; 300 0.323 0.975- 1.165 0.632 2.39 Table 9

Effect of Resin Uptake on Bridge Load and Deformation Properties a 2.5 cm thick sample of a polyethylene-polyurethane composite body with 4 pores / cm at 24 ° C (The polyethylene raw material had a melt index of 22, Grain size corresponding to 0 -, - 3O- mm mesh size; and density 0.916)

Tension OfI Polyathy * - Applied pressure in kg / cm

in./in. holder 130 ^ 1 267fl 310 $ Polyethylene

■ recording

0.1: ν: '0.4. 0.274 0.421 '.' ■ / 0.54Bv - "

0.2; 0.4 0.288; 0.464. 0.604

0.3:. _:: 0 _y 42; 0.316 0.527 0.689 '■ ;; ",.

0.4 0.45 0.365 0.632 0.843 ■ "" ■; ■■ '■.' ■■ - ■;

0.5 0.5., ^: ; 0.435 0.733 _: 0.984 J.

0.6; 0.6. ; ■■■ -, .0.562 .1.054 / 1.265

0.7. .0.8; 0.805. .1,476; 2,109.; .; -

0.75 ^: - ■: - - ^: 3.093 ■; ...:,. , ■ '.

0.8 1.52 ;; 1.406 3

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Pressure-stress-stress indicators of a 2.5 cm. " thick, 2.5 pores / cm containing, covered with polyethylene » drawn polyurethane foam '(The polyethylene base material had a melt index of 22, grain size of 0 °, 30-, density 0.916).

The tear strength of coated with polyethylene 267 $ polyester polyurethane foam with k · pores / cm falls in the temperature range between 24 and 82 ⁰ G ⁰ C for every 6 ° around Ο '3Λ1 kg / cm ² from.

At a load, as it is required for $ 25 bending at room temperature, remained with 170 $ '$ 267 and $ 310: Polyethylene coated polyurethane foams with ^ pore / cm up to about 99 ⁰ C up-efficient, the same composite material also suffered in a 1.20 m high stack. Lingering in boiling water for 30 minutes, during which the 25.4 mm bottom piece suffered less than Ϊ5% shrinkage. * The above values show that the composite body according to the invention has higher collapse temperatures than polyethylene Foam with k pores / cm and a coating made of polyethylene with melt index 3 and density 0.918 was compared with the same foam but in which 70% of the polyurethane was leached. Samples of both 5 x 5 x 2.5 cm each

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Varieties were loaded at 0.35 kg / cm and kept in an oven at 93 ° C for 15 minutes. The comparative results were: The deflection of the composite material at room temperature was 25% and after heating 53.5%, while the released material was 5% or 68%, but that means that in the composite material there is mutual reinforcement occurs, would be collapsed by slightly so at the same load of Polyurethankör- the higher load-bearing -. capability at elevated temperature has the cooperation of the two "materials out. . ; :.

All physical properties were, as far as not otherwise stated, according to ASTM specification B 156 ^ -59-T evaluated. ; : '■.'. ■ _. ■ "■". . ^

Example 6 ;. ■■., ■■; _ ..- ■

A 15 χ 15 χ 2.5 cm sample of "Scott Industrial Foam" with k pores / cm was coated with polyethylene powder (Microthene 710, ISI * Chemical Company, grain size corresponding to 0.30 mm mesh size, melt index 22, density 0.916) by first moistened with --Hasser, then dusted with polyethylene powder "and dried and finally the powder by 10 Rear heating at 180 C to ^Q; was brought Ansehmel-zen" / the fairly short furnace =

A dwell time of only £ 0 minutes was chosen - deliberately, so that the melted resin would definitely not completely cover the substrate - and - a later acid attack allowed. The powder application method can be lost depending on the type of coating desired. A similar procedure was used with a polyethylene powder of density D _} '| 5. Instead of polyethylene, there is also polypropylene. powder usable. ' ■

Example ?; ■;

The sample prepared in Example 6 was hot first for 5 1/2 hours at 6O ⁰ G and then immersed 6k 1/2 hours in normal tempered Some hydrochloric acid and then washed and '■ dried. ^; This would convert all of the polyurethane foam into another substance. The polyethylene coating did not appear to have been attacked by the acid. The above-mentioned foam was also treated explosively with an explosive mixture of oxygen and acetylene, which resulted in changes in properties, such as melting of its hips and nodes. :

Example 8 .- \ .-. ■ ... '■: ".

I90 χ 36 x ..- 2v5. cm large panels from: von der Flrmai, ScOtt .. · ■:

Paper Company, Foam Division, Eddystone, Pa, USA, polyester-polyurethane foam already obtained in a network-structured state with adipic acid polyethylene glycol ester as the ester component was moistened in an immersion tank and adjusted to k5% water absorption - based on polyurethane weighted "- while being passed through a pair of squeezing bolts These moist plates were penetrated through and through with polyethylene powder (corresponding to Eom size. 0.30 mm mesh size, melt index 22, density 0.916) and then heated to 195 ° C. for 15 minutes, "■ '■ -. This measure was repeated. . -

To the same foam density 0.918 and grain size trarde according to the same procedure polyethylene powder of melt index 3, corresponding to 0.50 mm mesh size to overall - melted, wherein the melt index of by the change: - needed 22. 3 additional melting time, if the powder in two stages was applied.

Samples were cut out on this foam and examined in accordance with ASTM Normvorsehrift D 156 ^ -59T. The - Results are listed below and discussed.

Increase the melting point of the melted polyethylene causes, as the tables show, a drastic increase

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Table 11 -

Compression load-deformation relationships with 4 pores / cm for the foam according to Table 10, however, with a coating of $ 300 Made of a polyethylene with a melting point of 22 and a density of 0.918 without acid leaching. ■ -.

load
in kg / cm ^ Table 12 Deformation % l%
'- 25.4 mm per. 25.4 mm - 0.464 0.1 ■.-.- 0.478 0.2 0.492 0.3 0.548 0.4 0.632 0.5 0.880 0.6 1.546 0.7 3.515 0.8

Pressure load-shape relationships in foams according to table 10, but with a coating of one Polyethylene of melt index 3 and density "0.918 without Acid leaching. - ^

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Load in
kg / cm Deformation m
25.4 mm per 25.4 mm 0.675 _ "0.1 - _ 0.844 0.2 0.950 0.3 1.090 0.4 1,335 "' ^: "-' 0.5. .'.- ' 0.6 2.812 0.7 - - 0.8
"- - ■ ■ -. Tabel

Compression load-deformation relationships in the case of the overlaid foam according to Table It, but after leaching of about 95% of the polyurethane with hydrochloric acid *

Load in. Deformation in kg / cm 25.4 mm per 25.4 mm

■■■, 0.147 0.1

η 107 0 9

0.210 ■ o,; 3 ■. ' ■■■ ..

0.253 0 | 4,. \

0.323 ^; 03

; j 0.478:. ; . . ■ ^; 0.6 V:

3, Ό93 ■ / "■ -VV- 0, -8.; V - .- ■ "" ■■■■ ■ -.- ~ 32-

Table 14 ■ _- ■ .-. '

Compression load and deformation relationships in the case of the overlaid foam according to Table 12, but after leaching of about 95% of the polyurethane. With hydrochloric acid »

Load in
kg / cm ² Deformation in
25.4 mm per 25.4 mm 0.1898 0.1 - 0.323 0.2 0.449 0.3 0.548 0.4 -: 0.740 Ϊ - 0.5: ■ ..; ■ 1.054 i, 757; ■ ' : - o, 7-: ■.;: : 4,218 ·: ■. ; .0.8 ^: ~ ■■■ -. ".

From the above values it follows that a net-structured body made of polyethylene, higher density, from the. _un-: Ferry 95% ö.es polyurethane is removed. compared to a) Poly- coated with low density polyethylene. _: urethane and b) a body made of lower density polyethylene (from which 95 $ of the polyurethane has been removed) has excellent structural properties

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& V

considerably less stiff structure. -

From the above data it can be seen, "that the according to the innovation, self-supporting, netζstructured, polyol. fin bodies especially for acid or alkali filtration or defog,

Polyethylenes of higher density from about D , 95 and above and polypropylenes give a stiffer and stronger structure, while polyethylenes of lower density give weaker structures. Λ

Solid body ettsa made of polyethylene with a density of preferably about .0.935 to about 0.970 are preferred.

Polypropylene bodies are also very good because of their generally higher stiffness compared to polyethylene useful, but need a high temperature stabilizer or an anti-oxidation agent .: '

If necessary, a polyurethane foam can also be used initially coated with polypropylene, from which the polyurethane is removed and be newly coated with polyethylene. Here but the margin between the melting of the polyethylene and the collapse of the foam body is much narrower than in the case of polyolef in ~ polyurethane combinations: is, ea comes here- ' with on exact temperatural roll "an * -— ■

Claims (1)

S 52 597 / 29b Gbm
Soott Paper Company Protection requirements 1. Power structured body, characterized in that it consists of a polyolefin or polyolefinbeschichtetenPolyurethanverbund and its ribs elliptical cross-section aufweisenund "distance, by nodes into a coherent body are united, wherein the polyolefin is present in at least the same amount by weight as the optional ^{polyurethane:} is -.- ■; -. ■ ■■■■■. ■ - ■.:;. ■■■. ■■.,. ■ ■■■ -.: ■ '■■. ■; ■ 2. Body according to claim 1, characterized in that its pore size is between about 2 and about 24 and preferably is between about 2 and about 18 pores / cm. ■ 5. Body according to claim 1 or 2, characterized in that its polyolefin component consists of polyethylene or polypropylene. ^: ; -. "." / H- . Body according to one of the preceding claims, characterized in that its possibly present polyurethane component consists of a polyester polyurethane. ^ *? ^^ yiy "K * .." Krt ~ .n. .ι » , ... ι, .ι ι u nit n« »'i iiiWi ^: ' ^t: ^ ^; ^^ ^: ^ 'y ^: T ^; ^ ^ 5. Body according to one of the preceding claims, characterized the characterized in that / polyolefin is practically membrane-free and has about 2 to 2k and preferably 2 to 18 pores / cm., 6. Body according to claim 5 *, characterized in that the Polyolefin consists of polypropylene-polyethylene composite material. Il tt 11 Il Il H IMt It Il Il /.r'Mf/ -3t