DE1652405A1 - Dispersing plastic fine powder in cloud form - Google Patents

Description

[Specimen copy I

Dart not changed v
DR.-INO. WALTER ABITZ 1652405 SMdHcMn. ,,,

DR. DIETER MORF T.Won 483225 and 48 * 415 Telegram"! ChemJndus Munich Patent attorney

January 12, 1967 KDCC 82

NATIONAL DISTILLERS AND CHEMICAL CORPORATION 99 Park Avenue, New York, N.Y., V. St. A.

Dispersing Plastic Fine Powder In Walkenfora

The invention relates to a new method and an apparatus for handling and depositing plastic Jeln powder in micro size and in particular a new process and a Device for the even deposition of finely ground thermoplastic powder in micro green with different Densities and different particle sizes on one tape or another suitable document.

The powder coating of sheets made of plastic material or Paper or the like is known to the person skilled in the art. Such arrangements should be based on a fixed or movable one Tape base a suitable powder can be deposited or dusted on «with the tape and the powder later one

s 09 #ai mi m

SAD ORIGINAL

NDCC 82

Machining to be subjected to the rapidity of the thermo ^ t plastic (particles and the connection with the band «u. In this way, the coated strip can be passed through an oven and subjected to temperatures that cause swelling the thermoplastic particles and the anchoring with the formation of a firm bond and a coated surface » as desired «of a continuous or discontinuous nature.

These materials can be further used, for example, by means of heated or drilled orphans can be rolled under pressure in order to press the particles into the web and make them shiny To create surfaces or an intimate connection of fibers or fiber-like materials.

So far one has encountered considerable difficulties »um very finely ground thermoplastic powders of various densities (in the range from 0.910 to 0 * 965) and of various types To suspend particle sizes (from 2 to 100 microns) in a suitable manner and to precipitate them equally.

The main object of the invention is to provide a new method and apparatus for trooken coating of particles on a pad, preferably using

SAD ORIGINAL

NDCC 82

of a new type of dust cloud generator that produces a precisely balanced Can create a cloud of dust from plastic particles of various densities and sizes. The invention continues to create a new type of dusting process for dusting micropowders on a base »whereby the method has a highly controlled supply and distribution level of the Plastic powder guaranteed.

According to a preferred embodiment of the invention, a ! Dry coating line constructed »which consists of four main components consists of: a pass-by oven, a settling chamber, a melting furnace and a dust cloud generating plant.

The preheating oven contains a suitable heating device, such as an edge-compensated radiator made of fairy-coated quartz with 2160 watts in an insulated housing. Bas tape, on soft · dust depressed is then moved through this housing in such a way that its surface touches a predetermined MaB8 is heated up, which is slightly below the minimum temperature «in the event of undesired changes in the physical or chemical properties of the tape take place · This surface temperature is naturally a Function of both the furnace temperature and the linear

98 38 ^ 6786

ßAD ORIGINAL

NSCC 82

speed, where, for example, for a paper tape linear ». speeds of 14 m / minute can be used.

The band then moves from Yorheisofen into a cleaning chamber, which contains a saturated cloud of the precipitating plastic parts, whereby the cloud is below the same level Conditions is kept. That means "the" the settling or coating speed of the powder dureb the supply of fresh powder is compensated. The pay strength is determined by the linear speed and the speed at which the powder is sucked into the chamber is steered.

The surface temperature of the foundation makes a fur of the thermoplastic parts, which fall on dl · ·· and thus creates an initial bond, which is the effect of the air currents, which originate from the movement of the base. " counteracts. If desired, this Xaamer can be of length, be subdivided according to a coating in different longitudinal patterns by shutting off different longitudinal chambers see below enable.

The dust cloud is then introduced through various feed openings in the front wall of the chamber, whereby these

9098 * 30/15786

6AD ORIGINAL

NDCO £ 82 *

openings can be used in any desired combination can »to bring about a suitable distribution of the coating.

The band moves with it. the one down on it Powder in a melting furnace, which is immediately behind the Coating chamber is arranged and contains suitable heat sources, such as two or more heating elements made of molten Quartz of 4320 watts, each of which is regulated by appropriate tempera t uric ont roll organs. The temperature of the enamel " furnace then causes the deposited dust layer to melt with the slightest possible increase in the temperature of the Basis. The furnace is preferably under bridge to prevent the entry of free dust particles. Let it be noted that the water chamber is also under a massive one Overpressure also works to prevent loose dust particles from entering

The final and essential part of the hampt system is the dust cloud generating device. Biese according to the invention, The new dust cloud generating device is designed in such a way that the filled plastic powder is filled by means of a large Volume of a low-pressure air flow is moved and distributed in the room. Escaping dust is then through suitable

-, 5 909838/0786 bad ORiGiNAL

NDCO 82

Lines or stirring the above-mentioned Absets- or Beachioh-

Tungekammer supplied.

The diohteausmaee of the dust cloud can van be partially closed off of the air inlet on the blower, which is the «interior of the · Dust cloud generator supplies air »direct.

The dust cloud generator according to the invention consists of two concentric wall parts, which are connected to each other aa floor of the chamber · You central chamber is then with The powder to be precipitated is filled and two air sources are connected to the unit, first to the annular chamber which concentrically forms the main chamber and the second to the interior of the main or central camera

The air flow from the Konsent & aeh surrounding the main sea Chamber then passes up through the floor of the main chamber and by the mass of the powder contained therein. In conjunction with the air which is supplied to the interior of the chamber, this causes a cloud of dust to be generated can be removed through suitable lines to the settling chamber.

This is followed by a more detailed description of the invention with reference to the drawings:

. 6 909838/0786

BATH ORIGINAL

NDCO 82

figur 1 fiddled with a built-up fiddle Partial equilibrium training route.

Pigur 2 is a cross unit of the type constructed in accordance with the invention Dust Clouds ~ Erseugere

Figure 3 is a reflection on the dust cloud generator of the figure 2.

FIG. 4 let a perspective view of the settling chamber used in FIG. 1 in a bent apart arrangement.

Referring first to Figure 1, a tile scheme is illustrated therein "which seigt the effect catfish a BeetKubungsstreoke using the present invention _f wherein a ZufUhrungstronmel 1 (ty may be that, for example, dee a roll paper su be coated, in a conventional manner fixed on a pivoting Aohsotütze 11 attached let.

Let it be noted that although the invention is here below With reference to the coating of paper is described »it offers various application possibilities and for example for coating fixed objects or

- 7 §09838 / 0786

SAD ORIGINAL

NDCO 82

Used to cover plastic sheets or the like can be.

The lane 12, which is removed from the roll 10, "is sent to the stage of a Vorheleofen _t eu welohea appropriate (not shown) He!" Arrangements and a conveyor system belong "receives the conveyor belt 14 · that runs in the specified direction», including the Lane 12 by moving the preheating oven 13 from left to right bu. Matching openings or gaps are provided at both ends of the Yorhel furnace to enable the entry and exit of the tape 12 bu

The Yorheisofen 13 causes an initial Aufheieen Basis of Volume 12 to it for Abaetsen the jam powder from the Absets- oder Besohlohtungskamner 20 to prepare. The Absetskaamer 20, which Oi Figure 4. Be more in one » is written, contains an essentially closed Chamber with a removable lid which is dustproof Forms connection with the upper end of the chamber 20 and be * sitBt Bwel openings, 22 and 23, which provide access for both enable the path 12 as well as for the conveyor belt 24, which guides the belt through the dispensing chamber.

A compressor 25 is attached to the upper end of the chamber 20.

- θ 909838/0786 BAD original

NDOO 82

closed to the introduction of a slow flow of air into the To enable the interior of the chamber, which is intended to generate an overpressure therein and in this way the entry of free powder in the openings 22 and 23 prevented. It should be noted that the right end of the chamber 20 is provided with an impact surface let, which consists of the sliding plates 26, 27 and 28 and the pressure releasing for the air flow from the chamber 20 and duroh the outlet opening 23 via a winding Way made possible. A vacuum chamber 30 can then be connected directly adjacent to the outlet opening 23, which absorbs excessively loose powder that is deposited on the web 12 is located.

As will be described in more detail below, there are three Discharge lines 31, 32 and 33 from a dust cloud generator 34 connected to the left end of the settling chamber 20. As soon the dust is deposited on the web 12 within the settling chamber 20 is, the web is forwarded to a melting furnace 40, which has its own conveyor belt 41, with the temperature is sufficiently high within the furnace 40 to melt the powders deposited on the web to effect. After that, the web becomes a suitable roll-up stage 42 is fed, where, after a sufficient time has elapsed, the precipitated on the web 12 to cool

909838/0786

NDCC 82

Plastic layer is rolled up. It should be noted that a pair of matching press rolls are positioned in front of the reeling stage 42 may be to compact the molten plastic layer on top of the web 12

The dust cloud generator 34 mentioned in FIG. 1 is shown in detail in FIGS. 2 and 3; from these figures it can be seen that the dust cloud generator is formed from a first steel cylinder 50 made of 8, on which a base plate 51 is welded on. Then an outer annular chamber 52 is formed by means of the inner cylinder 53, the is welded to the upper disk 54, which in turn is fused to the outer cylinder 50. Furthermore is a metallic guide device 55 in a suitable manner on the base plate 31 attached, which directs the flow of air from the annular chamber 52 upwards into the interior of the cylinder 53, the is at a distance from the upper surface of the base plate 51.

A head piece 56 is also screwed to the disc 54 with suitable screws 57 and 58, the head piece 56 being a Air supply line 59 and three outlet pipe connections 60, 61 and 62 which can be connected to lines 31 »32 and 33 of Figure 1» The upper end of the ring- '

- 10 909838/0786

NDOO 82 Ai

Shaped chamber 52 is also with .matching inlet lines 63 and 64, the lines 59 and 63 being connected to the same compressor 65. Line 64 is also provided with a suitable drain valve 66 to to allow air pressure to be released from the annular chamber 52 "

For operation, the head piece 56 is removed from the disk 54 and the inner cylinder 53 »which is about 63 to 5 cm high aein can, with a suitable plastic powder to about 1/3 filled to 1/2 of its height. A suitable plastic powder is a polyethylene powder which is available under the trademark "Microthane" from National Distillers and Chemical Corporation is known.

The headpiece 56 is then used together with suitable (not shown) Sealing means screwed tight and forms an airtight connection with the disk 54 »of the compressor 65 is switched on and results in an air flow through the lei « device 63 and the annular chamber 52 of approximately 47 Iiter./Sec * The Air flow which is fed to the line 59 is approximately 24 liters / second, with the line 59 on a Extends length of about 25 cm into the cylinder 53 and up close to the height of the plastic powder filling in cylinder 5? enough.

- 11 - ORIGINAL BATHROOM

909838/0786

NDCC 82

The bridge and the air turbulence which are created inside the cylinder 53 are then such that they generate a dust cloud with a slight overpressure (based on the pressure in the settling chamber 20), which through the pipe connections 6O ₉ 61 and 62 into the corresponding lines connected thereto and into the settling chamber 20 according to FIG. 1.

The settling chamber 20 is also shown in Figure 4, with the lines 31, 32 and 33 at the left end of the settling chamber are shown connected near their upper edge o

As emphasized above, it has been found that by arranging the dust cloud generator and the settling chamber in the in the figures 2, 3 and 4, dust from particles of different sizes and levels within the settling chamber 20 in one can suspend equilibrium-like state, the amount of dust entering the chamber by that amount is compensated, which is on the track, which by the conveyor belt 24 is passed through the chamber; precipitates. The amount of powder applied from the dust cloud generator is, can be directed by a suitable setting of the drain valve 66 in line 64 according to Figure 2, which the Regulates bridging conditions within the dust cloud generator.

- 12 -

909838/0786 BAD original

NLL ¹ C 82

Another embodiment of the present invention is shown a novel system in which a cloud of fine particles in a directed average density of a novel oleloh * * weight dust chamber is fed and suspended in it « Holding outlet and supply lines connect the equilibrium dust chamber with a sedimentation chamber, which the Bkhn absorbs, with the flow of particles of micron size through the system at the same time with average distribution the lights are led to the settling chamber.

This other configuration can best be understood from the following description in connection with FIG vrden which sohematlech the device according to the invention ecleansed.

Figure 5 shows a hopper 110, which the fine powder holds which are coated on the moving web 111 should} the sheet can be made of thermoplastic material or any other suitable sheet that serves as a base for the Powder to be precipitated is used. The hopper is filled with suitable plastic particles, such as ground polyethylene particles, filled, which under the name "Microetbene", a registered Trademarks of National Distillers and Chemical Corporation or any other appropriate

- 13 909838/0786 _ßA0

NDCC 82

■ powdery powder with a particle size range τon 2 to 100 microns and with densities ranging from 0.910 to 0.965.

The filling funnel is also connected to a gassing feed screw conveyor 112, which revolves like a rope to convey the powder out of the funnel 110 with a closed feed can 113 »u. The feed door 113 is provided with a sealed upper cover 114 which has a vacuum motor 115 inside which, during operation, evacuates the interior of the feed door 113 through the valve 116 and the blue pipe 117. The upper cover 114 also receives a line 118 to "carrying an extensive guide plate 119 and is connected to a matching Luftzuführungemotor 120, which air passes through a Peuchtigkeitsfalle 121 SiIicagel, filtered to use to guide a air in \\. M Suführdose 113 safety.

Furthermore, the cover 114 is provided with outlet extensions 130 and 131 provided, which with the supply lines 132 respectively 133 are connected to the equilibrium dust chamber 134 » Us it should be noted that the line 131 and its feed 133 end at the left end of the dust chamber 134, while the line 132 ends at the right end in the dust chamber 134 at

- 14 90 9838/0 786 BAD original

NSCO 82

the discharge line 135 emptied *

The Oleiohgewiohteetaubkanuner 134 still has a majority of auditorium lines 136, 137, 133 and 139 · whichever a control valve 140 to 143 or pressure gauges 144 to 147 carry. Audience lines 136 to 139 and further connected to a settling chamber 148 which has an inlet port 149 and an outlet opening 150 for receiving the tape 111 owns. The openings 149 and 150 are preferably sufficient tight to precise control of the pressure within the settling chamber 148 with a pressure bladder labyrinth 151 ensure that it is connected to the opening 150 for releasing air pressure, so that within the settling chamber 148 a constant pressure can be maintained.

In order to have a predetermined amount of powder on the web 111 during operation To knock down, the yakuum unit 115 is turned on and filtered inlet air through line 118 into the feed can 113 pressed. The pressure in the can 113 can be approximately 2.5 to 435 mm water column range. This overpressure then drives the fine powder coming from the hopper 110 through lines 130 and 131 out and into the interior of the equilibrium dust chamber 134, which is held at a pressure of about 2.5 to 435 mm of water. The cloud density of the

- 15 909838/0786 BAD ORIGINAL

NSGO 82

Ak,

Powders maintained within chamber 134 is, can be windigkelt sttr through the air ducts Feed box 113 regulate "with a lower air flow inhomogeneity sur feed can 113 has a lower density of Cloud within chamber 134 caused and reversed

It has been found «that a device of this type causes # that the powder particles are kept in suspension in the cloud chamber, even if they have different particle sizes and have a different view without selective settling of different particle sizes and different particle densities from the rest of the suspended powder.

The powders are then removed from the dust chamber 134 through the lines 136 to 139 by opening their control valves HO to 143 »us appropriately. Bl e * & valves are adjusted in unison until their different Sruokesser 144 to 147 indicate the same pressure «whereby the movement of the air and the powder contained therein ceases to exist. Lines with a balanced dispersion or a uniform distribution of the different particle sizes sen and particle densities takes place. Under these conditions, the settling chamber is preferably kept at a pressure of about 2 «5 to 433 ma water column, in order in this way to be completely exhausted.

- 16 -

909838/0786. BATH

NDCC 82

geglichenes pressure system upright except hold ₀ ^ ^ie through the lines 136 to 139 passing particles are then deposited on the web 150 "as it passes through the settling chamber 148, the web and the particles thereon are anschliesaend further processed in any desired manner"

The flow rates through the various lines 130, 131 and 136-139 can of course be through the Resistance coefficient of these lines can be influenced. It is therefore preferred that the interior of these tubes or feed ducts be exposed to the flow of micron sized particles, who are led through this, offer as little resistance as possible "to oppose"

- 17-909838 / 0786

Claims (1)

NDCC 82 January 12, 1967 Patent claims 1. Method of dusting a foundation with uniformly wet Distribution of powdery ropes of spanking-like particle size and various seals characterized by an apparatus including: a source for powdery © particles, a supply container, consisting of a chamber »which with the named source is connected and has an air supply, around the Suapen = to effect dation of the powdery particles and a settling chamber, In which the discontinuation of the suspended part » along a path which goes through the interior of this chamber is performed, is effected under controlled conditions. 2. Apparatus according to claim 1 for dusting a foundation with uniform distribution of powdery parts, different part size and particle density, marked by a Sfeaubfolken- ^ generator, a coating chamber, a helper and means for moving the said foundation From the settling chamber to the heating furnace, the dust cloud generator contains a first and second concentric cylinder, which form a central chamber and an outer annular chamber, and in which the central chamber and the outer chamber are connected to one another at their bases 909834/0786 _Λ . _Λ - TO - BAD OHiG _fNAL HSCC 82 are and the central chamber a loading of the powdery ! Absorbs particles "as well as air compressor units, which are connected to the upper end of the central chamber and the upper end of the annular chamber, and Outlet lines leading from the top of the central chamber lead to the sedimentation chamber. ' Device according to claim 1, characterized by a feeder box, consisting of a closed chamber, which is connected to a source of powdery particles is, a blower pump unit, welohe with the feed box is connected to put the inside under Druok bu, a directed supply source for dry air, which is connected to the feed box in order to be controlled Conditions of introducing dry air into the pressurized interior of the feeder can, an oil weight dust chamber, consisting of a hermetically sealed elongated chamber, a first and «wide outlet channel, which extends from the feeder door and connected to the interior of the dust chamber in first and »wide spaced apart sections is, a settling chamber with inlet and outlet openings for the passage of a tape through the interior of the settling chamber and a pressure relief vent, whereby the equilibrium - 19 909838/0786 jjaD ORIGINAL NSCO 82 dust chamber a large number of protruding lines owns «which is derived from its interior rura sections in corresponding interior sections of the settling chamber at their the upper end and above the belt guided in this settling chamber. 4. Apparatus according to claim 1 to 3 »characterized in that that the air flow into the annular chamber is about 47 l / lake. and the air flow into the central chamber is about 24 l / sec. 5. Device according to claim 1 to 4 »characterized · the particles have a size in the range of 2 to 100 microns and have densities in the range of $ 0.910 to $ 0.96. 6. A method for coating a single base, characterized in that that one preheats the base, creates a dust cloud, which is saturated with plaatikeilohen, this one A cloud of dust feeds a settling chamber, the basis of the Settlement chamber for a sufficient period of time to allow the deposition of a layer of plastic particles on the Allow the base and heat the base to a temperature sufficient to allow the plastic particles to melt on the basis to enable. - 20 - 900838/0786 _ftAnΛΛ BATH ORIGINAL NSCO 82 7 · The method according to claim 6, characterized in that the Plastic particles range in size from 2 to 100 microns own. 8. The method according to claim 6, characterized gekennaeichnet that dl · a · Flaetlkteilchen Diohte in the range of O have ₁₉₁₀ to 0.965 " 9. The method according to claim 6, characterized in that the Base is subjected to a pressure treatment after heating. - 21 - BATH 909838/0786 Blank page