DE1629321A1 - Method and apparatus for making cellular products from synthetic resin - Google Patents

Description

Dlpl.-lng. R. H. Bahr PIpL-Phys. E. Betzier Dlpl.-lng. W. Herrmann-Trentepohl PATENT LAWYERS

ν '469 Hemt, den

^: Freillgrathstrasse 19 P.O. Box HO /

ROQ 3 9 1 Telephony Herne S0930 and 51582

D £. P OL 1 _ΤβΙθΧ 08229W3

April

Munich 13, den , Alter St. Georgeplati 8/11 Telephone: M α nc K β π 35 2β 28 Telex 05245fö Post delivery requested to 469 Herne, PO Box 140

File no. Ä J6 Y99 Iw / Pi t Please state in the answer

Company de Saint Gobain

France

Method and apparatus for making cellular products from synthetic resin

The invention relates to the manufacture of cellular Synthetic resin products such as expanded polystyrene foamed elements or pearls *

These products are especially intended for insulation purposes and have good mechanical properties and a low density.

The manufacture of these cellular products, e.g. B. off Polystyrene foaming, is generally carried out starting from small elements, e.g. B. Granules of thermoplastic resin to which a blowing agent is incorporated. Under the influence of Heat, which causes the release agent to volatilize, these granules are transformed into foamed beads.

A known process by which the foamed beads are shaped to produce a cellular product desired shape by internal pressure due to expansion of the granules at the time of the volatilization of the propellant takes place, does not allow the production more homogeneous Low density products. The low-density products are particularly advantageous because there is less material to manufacture the same insulation performance is required; so they are particularly interesting from an economic point of view.

The method according to the invention relates to the use of pre-expanded beads and their subsequent use Compression, causing agglomeration and 'the Formation of a product of desired dimensions is caused. The related pearls can be Polystyrene foam beads are the subject of the application filed in France on April 14, 1965 is (French patent no ........ corresponding to French

safe patent application 13 184, German application

009886/1739

(internal file; calibrated in 798 of the same day) and subject of the French patent ...... (French

Registration 13 185), which corresponds to the German registration (internal file number: A 16 800). These foamed Pearls "in particular have the property of ice, an apparent one to have specific gravity in the range of 5 kg / m or less. You can following the procedure as it is in the first-mentioned patent is described, are prepared, after which with air to a temperature of the foamable Granulate is preheated above 90-100 ° C, the latter then being treated with steam. You can but also obtained by the method of the second patent .., according to which the granules are initially at ambient pressure be pre-foamed by the steam and then, after conditioning, treated with steam in the autoclave.

According to the invention, the beads are now heated to the softening temperature during a first phase, during a

second phase to achieve sufficient thickness and final

ger density subjected to a pressure, and during a third Phase with the application of a pressure sufficient to maintain this thickness, cooled.

The heating of the pearls. Which is the first phase of treatment represents, is advantageously carried out by means of hot air. Pressurized steam can also be used «

. ''; ^ ■■.: - 909.8B6 / f73; t - / oV ^: \

During the first phase, the foamed holidays are allowed no pressure whatsoever * - "But Jüan can too the pearls unite during part of the entire phase subject to certain pressure which, applied during the plastic state of the pearls, a diminution of the Thickness of the overall arrangement results in a Reduction of the gaps between the pearls,

Due to the use of hot air during the first Treatment phase can / work at ambient pressure. Through this can, if necessary, the puffing of the pearls to ' Time of their heating up can be reduced * Otherwise During this first phase it becomes important to know the temperature precisely to control »If namely the temperature of the heating if it is too high, the pearls will shrink; is the temperature too low, the result is poor agglomeration.,

The second phase, which corresponds to the shape of the product, is achieved without the use of heat by keeping the pearls at the temperature reached in the first treatment phase being held. .

The material is advantageously kept at the same thickness during the second and third phases. According to the invention, the same pressure medium is provided during both treatment phases in order to maintain this thickness

to be used » _A " - '■ "■■' ■ ·

■ ... "009886/1730". '..

It has been found that the apparent density (density a certain volume occupied by pearls and spaces) depending on the final density of the one to be obtained Product is to be selected. Pur a certain density of the end product has, if the apparent density · too low is, the product holes on; If the density is too great, so the end product does not show the good mechanical properties. The most favorable ratio between the two densities is 0.4-0.6, preferably 0.5.

The inventive method can be discontinuous and ' be carried out continuously. For example, embodiments the invention will now be based on the enclosed, Lowing drawings explained in more detail in which

Pig, 1 a molding tool for carrying out the discontinuous Procedure is;

the pig. 2, 3 and 4 schematically show different treatment sites according to the batch process;

Pig. 5 pelgtf partially in section, a device for

implementation of the continuous process;

5a; isi; a detailed view;
: 009886/1739

Pig. Fig. 6 shows in perspective such a device;

the pig. 7 and 8 show details "in the transition of the Material from the heating zone into the printing zone.

In a form 1, with a perforated bottom 2, surrounded by a Thermal insulation 3 leads to foamed polystyrene beads low density and puts a perforated cover 4 on, which penetrates the mold and acts as a piston for the Compression in the output stage is used. The lid is in contact with the top level of the foamed beads used without exerting any noticeable or only very slight pressure on the pearls.

By blowing warm air from a diffuser 5 is then the heating of the pearls is carried out. The temperature of the air is between 103 and 130 ° G, blowing is 10 seconds to 3 minutes depending on the temperature maintain. The temperature of the air must be above the The softening temperature of the pearls and the higher the shorter the duration of the heating. The choice of air temperature also depends to some extent on the heat transfer through the bottom of the mold over which the blowing occurs. Similar products can be produced in the same mold by heating them up for three minutes with air at 112 ° C, a 60 second long heating with air at 170 ° O and

009886/1739

_ 7 _ -. '■' ■ '-. ■■ "■■' ■

with air heating up for only 12 seconds 120 ° σ obtained. ',.,.:. \ "-" ■■ ^

As mentioned above, the 'air temperature' must be precisely dependent of the following major players will be hired; If after. the Pörlen are not well welded to one another during the pressing process you have to increase the temperature. ■

If, after the pressing process, the product "is shrunk." has an ugly appearance, you have to adjust the temperature Reduce. χ.

After the end of the first treatment phase, ie already when the heating of the pearls has ended, the lid 4 is pressed into the mold as a result of the actuation of a press until the volume of the perXen has reduced to about "half, including a compression ditch between 'Q , 5 and 4 3? Cans per m of mold cross-section, depending on the temperature reached: and the specific weight of the product. The lowering of the lid must be followed quickly at the beginning and slowly at the end of its path. The compression time is in the range of νοϊί 5 seconds for a distance of 10 cat. Cooling jd "h _for the third phase of treatment - must in fes i · AufreehtÄrhaltung of during loading © ndigiang of Preßvorgaages srhaltenen Dicka be performed. This cooling will, down to such a low level

Temperature continued so that the product does not expand again.

In practice it is advantageous, especially in manufacture of molded articles, different like shapes, e.g. B. to choose three, one after the other to the filling point and Heating point by means of air (Fig. 2), to the pressing point (Fig. 3) and to the place of cooling (Fig. 4) are brought. the three treatment phases are therefore one after the other in the same form carried out. ;

As shown in the drawings, the cover 6 of Molds 7 latches 8 which ensure that the lids are held in place in their position, which they take at the end of the pressing process and during the cooling process. In all cases can or can the mold (s) are filled with already warm pearls.

Fig. 5 and following relate to the implementation of the continuous process according to the invention.

The low density beads are placed in a feed hopper. These pearls can in particular from the shown in the drawing of the first-mentioned patent specification above Device originate with the feed hopper arranged behind the crushing roller system of this device is, if necessary with the interposition of a heating

009886/1739

162932T

fung switch.

The pearls are transported over one or more tendons 10 introduced into the first part of the device, the two has metallic endless mesh belts 17, 18, between which the pearls are grasped and transported to the rear. By the screw conveyor 10 can in addition to the transport of the foamed material a certain pressure on the material * be exercised and a favorable. Sew the filling of the space the two bands can be achieved. During that first one Part of their way, the pearls are heated by hot air, which is inserted into a lower box 11 and to a upper box 12 flows after having the bulk of the pearls has prevailed ·. The two boxes can have partitions 13 for subdivision into different departments 14 ,; 15, 16 exhibit. ''

The conveyor belts 17 and 18 limit the thickness of the pearl layer and make a suitable flow of warm air possible. This causes a slight agglomeration of the pearls with one another. The two conveyor belts 17-18 can be arranged parallel or slightly inclined to each other be so that the height of the pearl layer depends on the feed is decreased, and so a slight compression of the

/and
Perlen'a reduction in the space is effected.

009886/1730

It is intended to use these "two arrangements" one after the other to be carried out, either by means of the same pair of conveyors or by using several pairs of consecutive ones Sponsor.

In the front part of the device, a low suction effect can also be set up in order to keep a Causing air flow transversely to the feed device and around the coring of the pearls in the feed hopper 9 to facilitate. .

Near the exit from the conveyors 17-18 is the agglomeration state of the pearls such that air can flow through the product less easily; for this you can just use a stream of warm air in this part provide on the conveyors to reduce their cooling.

Upon exiting the first element of the device, a band 19 of sufficient cohesion is obtained, which is transferred into the second element of the device, this element having the task of bringing about the desired compression. The second element consists of two endless conveyor belts 20-21, the high pressures, e.g. B, in the range of 4 tons per m. These conveyor belts consist, for example, of rigid metal strips that are articulated to one another. The two conveyor belts 20-21 each occur in _t

009886/1739

one of the boxes 22-23 through which the warm air flows. Inside the boxes there are more boxes in the back 24-25 provided, 'through which cold air flows. This air is sent to the conveyor belts to cool the product belt directed. An atomization of the cold liquid can also be provided. So one gets an element of compression whose front part is heated to bring the surface of the product to a level slightly above that of the mass to heat the lying temperature and to ensure a surface treatment of the strip during compression, whereby a compression of the material is caused over a small thickness and the rear part this Element maintains the pressure of the tape while cooling. receivesν -

The transfer from the heating element to the pressure element can be carried out directly, take place without any intermediate carrier. But it can also small, rotating rollers 26-27 are provided that the Inflation of the tape at the exit from the first element limit. It can also roll sideways with vertical ones Axes, relief wheels, caterpillar wheels, expansion rollers or the like. be provided in order to influence the shape of the edges. The material is in place during this transfer process in the semi-plastic state, which is cheap to manufacture A useful edge shape of the band is when plates are to be removed from the pressure element at the exit.

009886/1739

During this handover you can still see a slight overheating of the belt surfaces, so that on this a G-glaze is effected or a higher one Density in the layers adjacent to the surface.

The compression already takes place when the belt engages between the two conveyors 20-21. The latter lie parallel and thus maintain a constant thickness during the Cooling that behind the warm entry zone of the compressed Element follows. The distance between the two conveyors is practically the same as that of the product 19a to be granted thickness, while the distance at the entrance the conveyor belts 17-18 to the heating zone according to one expedient ratio with which the conveyor 20-21 is regulated to ^ io a density ratio of 0.4 to 0.6, preferably of 0.5 to be obtained between the foamed beads and the final product.

The warm air used in the pressure element permeates this Product not, but rather heats the endless belts of the Sponsor. In this part of the complex you can also find a Provide heating by means of radiation elements. These elements 43_43a (Fig. 5a) are preferably provided at the end of the conveyor belts 20-21, which is at the entry of the pressure element are arranged * The heating by radiation allows a surface heating of the conveyor * This surface

009886/173 9

- 13 - ';. ; .'-. ■ -; ■■■. ■

flächenerwämung makes possible an easier EndabktUilung j with a substantial heat and loss of time is avoided and cooling of the conveyor is obtained.

By regulating the temperature in the pressure element a value slightly above that of the pearls The surfaces of the product are glazed and the density in the layers near the surfaces is optionally increased will.

At the outlet from the device are "also facilities, z. B. Rollers or parallel belts provided to maintain a certain compression serve and, if necessary, a post-expansion of the material impede.

Suitable facilities, not shown, for setting the temperatures of the overall device are provided.

Pig. 6 shows the Pig device in perspective. In the drawing you can see at 28 a burner for heating the air, at 29 the heating chamber, at 30 the fan, by deir-the warm air is supplied through the lines 31 in the compartments 14, 15, 16 of the element of the device , which is used for Heating the beads is used; at 32 you can see lines through which the air is returned to the heating chamber.

009886/1739

to be led.

With 33 the burner for heating the air is designated at 39, this air is through the fan 34 and the Lines 35 in the boxes 22 and 23 of the element of the device that causes the compression of the product, sent; the air is then returned to the heating chamber via lines 36. At 37 there is another Detect fan that sucks in ambient air and through the lines 38 pushes into the cooling boxes 24 and 2.5.

In Pig. 7 is the transfer of the tape from the heating to. the pressure element shown, in the present Pail in the form of an arrangement by which the length of the belt part located in the transition is limited. According to this arrangement, rollers 40, 40a of small diameter are used, which are then arranged on rollers 41, 41a on which the conveyors 17 and 18 run. Favorable results are obtained if the compression of the belt is effected before it is introduced into the entry rollers 42, 42a on which the conveyors 20-21 run. This previous compression is made between points A and B.

If the speed of the conveyor is high, the reduction in the thickness of the belt would take place too quickly, "

Ö09886 / 1739

-1p- -

even if one has entry roles 42-42a large --- l) ur «hmess - erS; -. used-. The entry can therefore as in Fig 8, the conveyors 20-21 not being guided in parallel ' are doing so a reduction in thickness and thus one to obtain slower compression «The speed of the conveyors for both elements, namely the heating and compression elements, is practically the same, since the reduction in the thickness of the tape with an increase in the Density is going on. However, it is also possible with a small difference in speed between the conveyors of both elements to work.

Mm for the production of 1 m wide sheets having a thickness of 40, starting from foamed Tölystyrolperien having a density in the range of 4 kg / m, on a _machine: as shown in Figures 5 and 6, wherein a - ·. Conveyor speed of 6 m per minute, the duration of the various treatment processes is in the following range; ". ■

Heating up: 30 seconds; Compression: TO ^ seconds; Cooling: 3 minutes; The heating section has a length of 3 to 4 meters and the section of compression a length of 15 to 20 meters.

Claims: 009β86 / 1739

Claims (1)

-16- A 16 799 Lw / Pa P a t e η t a η s ρ r ü c h e 1. Process for the production of cellular products from synthetic resin, such as polystyrene foams, from foamed elements or beads, thereby g e k e η η ze i ch net that during a first phase the pearls up to Softening temperature heated during a second phase • these pearls to achieve sufficient thickness and final Density are subjected to pressure, and that during: a third phase the material is applied with sufficient pressure to maintain this thickness, is cooled. ' 2. The method according to claim 1, characterized in that g e k e η η ζ e i c h net, that the heating of the pearls, d. H. the first treatment stage is carried out at ambient pressure using warm air will. 3 · Method according to one of the preceding claims, characterized g e k e η η ζ e i c h η et that warming up by Steam is made under pressure. 4. The method according to any one of the preceding claims, characterized in that the temperature the air for heating the beads is adjusted so that after the pressing process products without voids' and advantageous Appearance are preserved. 009888/1739 - .1-7 - - ■. "; ^: ■■■. ■■■■. 5. Verfaliren according to any one of the preceding claims, characterized geke η η ζ eich η et that the pearls during the first treatment phase. Are exposed to ambient pressure. 6. The method according to any one of claims T to 4, characterized g e k e η η ze i c h η e t that the pearls during the are exposed to light pressure in the first phase of treatment. 7. The method according to 'one of the preceding claims, characterized G e k e η η ze i c h η e t that in the second treatment phase, in which the heated beads are subjected to pressure without heat, and the Pearls at the temperature reached during the first phase being held. '* v 8. The method according to any one of the preceding claims, characterized g e k e η η ζ e i c h η e t that the material in the same thickness during the second and third stages of the Procedures are held. 9. The method according to one of the preceding Änsprehe, thereby ge k e η η ζ e i c h net that to maintain this thickness the same devices for compression are used during the last two phases of treatment. 009886 / T739 10. The method according to any one of the preceding claims, characterized marked that with foamed beads an apparent specific gravity in the range of 5 kg / m or less is worked. 11. The method according to any one of the preceding claims, characterized e g that the various Behandiungsphasen be carried out batchwise> ke η ή ieich et η _f. 1-2. Method according to one of Claims 1 to 10 thereby g e- k e ή η ζ e i e h ή e t that the different Treatment phases are carried out continuously. 1 "3 ·. Device for carrying out the method according to a - of the preceding claims, characterized by a form ⁷ (1); with a perforated base (2) for introducing shop-fitef Pe-rlenj through a likewise perforated lid (4) for: covering the bead mass; by a hot air duct | 5) for the first process stage &; by actuating the cover (4) as a piston for compression during the second treatment phase, which is held in place during the third, the cooling phase. 009886/17 1B29321 14. The device according to claim 13, characterized in that g e k e η η ze i c hne t that several forms in succession correspond to the three treatment phases of the procedure Jobs are managed. 15. The device according to claim 13 »thereby ge ken η - ' ζ e i c h η et that the shape and · lid have a locking device (8) to keep the "lid in its position in the · To keep up with the compression '. V 16. Device for continuous implementation: the method according to one of claims 1 to 10, g 6 ken η records . through. a first of two metallic ones Maschän or perforated sheet having endless belts or conveyors (17-18) existing arrangement, between which the foamed beads, penetrated by the hot air stream, are guided will; through boxes (11 "; 12) arranged on both sides of the conveyor for the circulation of warm air; and by a second arrangement with two metallic, conveyor belts (20-21) consisting of articulated strips, which are placed on the one emerging from the first arrangement Material tape 09) the necessary pressure to: achieve apply the desired thickness; by heating devices (29 ...) for the conveyor belts in their front part and cooling devices in the rear part of the second arrangement. 0 09886/173 17. The device according to claim 16, characterized in that the conveyor belts of the first element, so as not to subject the pearls to compression, have a parallel course. 1.8. Apparatus according to claim 16, characterized in that the conveyor belts converge to to subject the pearls to a slight compression. 19. The device according to claim 16, characterized in that in the inlet part of the first element a downward suction is created, which facilitates the introduction of the pearls. 20. The device according to claim 16, characterized in that the distance upon entry into the Ribbons of the first element corresponding to that of the second element to a density ratio of 0.4 to 0.6, preferably 0.5 is set between the apparent density of the foamed beads and that of the end product. 21. Device according to claim 16, characterized geke η η-- ~ characterized in that the transfer of the band (19) takes place at the exit from the first element when it enters the second element via rotating rolls. 00988671739 22. The device according to claim 16, characterized in that at the edges of the belt (19) Devices such as rollers with vertical axes, relief wheels, or expansion rollers are arranged. 23. The device according to claim 16, g e k e η η ζ ei c h net due to a slight overheating of the surface end Band at the transition. 24. The device according to claim 16 ,. thereby g e k e nn ζ e i c h η e t that on the front part of the compression element Radiant elements (43-43ä) are provided for heating the conveyor belts. . 25. The device according to claim 16, geke η η ζ eich net by rolling small diameter at the exit from the conveyors from the heating element to limit the belt length during the transfer. 26. The apparatus of claim 16, geka η η ζ ei ch net by a compression of the _band: the vermindert.- zwischen.die its thickness prior to insertion conveyor (20-21) of the element ^ wide oo · ■ ■ ■ ■ ■ ""'"". ■ ' ^l ■ \' "^ - 27. Device according to claim 16, g e k e η η ze i c h - £ * ■ 'net through a tapered entry area between the conveyors (20-21) of the second element for changing the thickness of the belt (19) and for causing a slower compression,