DE7212994U - Device for testing the flow properties of plastic masses on rolling mills - Google Patents

Description

Description / - ·

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Applicant: Dr. Ing. H. Coliin, System Developments 800U Munich 13 Uohenzollernstr. hk

Designation: Device for testing the flow properties of plastic masses on rolling mills.

The innovation relates to a device for testing the flow properties of plastic masses on roller machines, in particular on rolling mills and calenders.

Xn the plastics and guami industries are becoming more diverse Way plastic masses kneaded on rolling mills and calenders and processed into foils and plates * To make predictions about to be able to make the processability of mixtures in the laboratory, Suitable measuring devices must be provided

According to the prior art, the flowability of plastic masses can be measured using a capillary rheometer Application of pressure by piston or screw presses; by Cuette viscometer; or by kneaders with kneading blades of various shapes. These devices all have significant disadvantages, particularly that of the specific nature of the Stress in a nip is not mimicked and thus the transferability of the measurement results to calenders is hardly possible is possible.

A wedge-gap roll viscometer is known from more recent times, in which an inner roller is arranged eccentrically in a heated hollow cylinder so that between roller and Cylinder forms a wedge gap and that the cylinder with a Pressure measuring device is equipped and rotatably mounted. (DGM 1995 733) This device has the advantage that the geometry and thus also the flow behavior of the tested material is similar to that in known roller gaps. However, there are the following disadvantages:

a) It is a completely closed system. As in a rolling mill, frictional heat cannot come from the free surface of the skin

blast, so the creep times of the tested materials are demonstrably shorter than with the open Rolling mill - the results are therefore not transferable ^

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förmigee polymer is very difficult because this does not shrink because of its low flowability into the gap, but caking on standstill Zylinderwar Λ "

c) The lateral seals are difficult, there are losses which in turn lead to a drop in the level of plastic mass - this changes the measured values.

The innovation is based on the task of overcoming the disadvantages of the last-mentioned device in particular, in order to finally obtain a measuring instrument for the roller laboratory that can be used in real practice

The innovation is that on part of the free circumference and part of the barrel length of a roller one Rolling mill or calender, a measuring bowl is arranged in such a way that a wedge-shaped storage space is created between the roller and the bowl and that the bowl is equipped with means for measuring the specific pressure arising in the pent-up dough. "

The new type of bowl rheometer is an add-on part that is attached to the known Wal ζ eruna machines from the outside. The PEIl circulating on the roller is dammed up in the stem · A circulating knead is formed, very similar to ± m roller gap. The resulting hydrodynamic pressure is characteristic of the flowability of the material.

The shell covers the roller only in a small part of the circumference, preferably 30 to 70 mm circumferential length. Through this Sufficient free surface remains in order not to impair the thermal similarity to real rolling or calendering change.

Shell has fibfinfa] is only ap p-erin, "-e width, in the

p of 50 "in the. Dad'Tch forces, which arise in the wedge gap, are of the same order, since ρ is safely controlled to avoid deformations and so with changes Ηητ Snal tvej.tp in operation »Is Hi e shell wide ytiiinM · to Röiiiieinfliia?, - n ;; 5 .'er; in dor with" ¹ ^ the ^ c ^ " ¹ ^ γ-ή- · - · ^ + - = arranged pressure receptors ^ n π nt crush.

Seen in the width of the roller, the oil receiver is arranged with ti 5 τ η of the shell, in the direction of the roller circumference; about the last third of the enjer verdeneden wedge gap.

A temperature sensor for determining the melt temperature can also be arranged in the further draw-in part of the shell.

The lateral sealing of the gap for each material outlet is made by 2 slidably attached or firmly connected sides of the side part Ie pntsnrirht the whale TPnranins, so - pressing the same against the roller a close-to- complete seal takes place. This side part - 'nd is provided with a slidable running layer on its side facing the roller. (e.g. bronze, fluoroplastics).

The side parts have only a small thickness (approx. 5 ■ · "") and run diagonally at the beginning and end, so that the remaining roller layer is pushed aside.

The side parts are also designed so that they are exactly as long are like the narrow part (measuring part) of the measuring bowl. This ensures that the putty always has the same fill level, even if the thickness of the incoming layer fluctuates. The superfluous plastic material overflows laterally (self-control) the filling level).

The smallest gap between the shell and the roller can be set are made by moving the side panels.

The measuring bowl is connected to the roller stands via a stable cross-member. The traverse is arranged to be pivotable easy cleaning.

The shell is by means of set screws opposite the traverse adjusted. Furthermore, strong disc springs are arranged between the shell and the cross-member, which the shell with certain Press pressure against the roller. As a result, the side parts of the shell are in constant contact with the roller and thus a precisely reproducible gap width. The spring force muli be greater than the highest separating force resulting from the hydrodynamic pressure

The bowl is provided with bores for the passage of maintenance fluids or for heating with electrical heating cartridges.

The advantages that can be achieved with the innovation compared to the prior art Technique are as follows

- Direct measurement of the flowability of plastic masses in the roll gap under largely similar geometric conditions; easily transferable results «,

- The measurement is carried out directly, i.e. no external influences such as friction of the bearings and seals (as with Torque measurements) must be taken into account.

- It is an open system, the thermal conditions of the examined mass at the measuring mill are relative small additional elements only slightly affected; i.e. also that The time behavior of the material is not significantly changed "

- The function * separation between plasticizing in the roller gap and measurement in the wedge gap means that raw materials in powder form can also be reliably tested.

- Pressure force * »and deformations remain small, since only a narrow one Section of the fur is checked

- Constant filling level and thus constant measuring conditions are guaranteed by the special design of the side seals

- In addition to the batch testing in the laboratory considered so far, the measuring bowl is a suitable means for continuous viscosity control on production machines such as calenders and Sireicha & seiiiaen »The measuring bowl can be attached directly to a Calender roll can be pressed, or an edge strip can be pulled off, which over a separate Wal * β with measuring

721299i.-7.ii72

shell is performed as a separate dimensional direction.

An embodiment of the innovation is described with reference to FIGS. 1 and 2. VüIb «1 and roller 2 are the rollers of an existing rolling mill, between which a kneading 3 made of plasticized material rotates. The fur k runs around roller 2. The shell 5 is positioned on roller 2 at a certain distance · The side parts 6 and 7 are held by screws. The adjusting screws 9 are used for the precise adjustment of the side parts with respect to the shell and thus for setting the gap width 10 between the shell and the roller. On the inlet side 11 and the outlet side 12, the side parts 6 and 7 are beveled. Are screwed into the shell, a pressure transducer 13 'a mass thermocouple ~ \ k and a Wandthennofühler 15, leads 16 and 17 of the heating of the shell are heat-carrier oil. The shell is supported on the pivoting cross member via disc springs 18 (1 °) · Adjusting screws 20 secure the position of the shell in the circumferential direction.

Claims (6)

Protection terms' 1.) Device for testing the flow properties of plastic Masses of orphan machines, especially rolling mills and calenders in the rubber and plastics industry by only a part of the free circumference3 as well as a part of the barrel width of a roll of a rolling mill or calender covering a measuring cup, which is so arranged is that a wedge-shaped storage space is created between the roller and the shell and which with means for measuring of the specific pressure generated in the pent-up dough. 2.) Device according to claim 1, characterized in that the measuring cup in the circumferential direction preferably kO to 70 mm and in the axial direction preferably about 50 mm long with the roller forms the measuring gap. 3.) Device according to claim 1, characterized in that the Pressure transducer is arranged in the upper narrow third of the gap in the shell. 4.) Device according to claim 1, characterized in that adjustable side parts are arranged for sealing which are adapted to the roll radius and provided on the side facing the roll with a smooth running layer are. 5.) Device according to claim 1, characterized in that the Side parts are just as long as the narrow part (measuring part) of the measuring cup and that the side parts at the front and rear The end taper to a pointed shape. 6.) Device according to claim 1, characterized in that the Shell is supported against a traverse via disc springs, the pretensioning force of which is higher than the highest occurring Mass separation force. 7 ») Device according to claim 1, characterized in that Γ d the traverse with the measuring bowl is swivel-mounted on the roll stand, 8,) Device according to claim 1, characterized in that the measuring bowl is equipped with means for heating as well as for measuring and regulating the temperature 72-2994-7.1-72