Note: Descriptions are shown in the official language in which they were submitted.
HOECHST ~;TIENGESELLSC~FT HOE 93/F 092 DPh.HS/we
Device for plasticating unidirectionally fiber-rein~orced
thermoplastic granules
The invention relate~ to a device for plasticating
unidirectionally fiber-reinforced thermoplaatic granule~,
compri~ing a plastication barrel in the conical eed part
and cylindrical discharge part of which a plastication
~crew i~ arranged.
The po~sible applications of thermoplastics can be
extended by incorporating reinforcing fiber3. By the
addition of long fibers (fiber length ~ 4 mm), all
mechanical characteristic values of thermoplastics c~n be
signi~icantly improved. Whereas the production of pla~tic
granule~ with the addition of long-fiber~ haa been
largely accomplished, the plastication and premolding of
such granules still causes difficultie~, since the fibers
are damaged when the known plastication apparatus is
u~ed. They are mechanically comminuted. The invention
intends to remedy thi~ situation.
The object i~ achieved by a device of ~he type mentioned
at the outset, in which the discharge part i~ provided
wlth a clo~able ~haping die and ~he pla~tication ~craw
ha~ an apparatu~ for axial displacement of the Rcr~w with
re~pect to the plastication barrel.
The apparatu~ for the axial displacement o~ the
pla~tication ~crew may co~pri~e controllable hydraulic
cylinder~. The hydrau~ic cylinder~ may be attach0d to the
pla~tication barrcl and the cloRure of the die may
comprise a guillotine knife.
During ~he plastication proce~s, the pla~ticakion screw
yields under the adjustable back pre~sure. After ~ill3ng
and opening o the die, the 6crew tra~elg in the opposite
direc ion towards the die and force~ out the pla~ticated
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material.
The device essentially provides the advantage that the
fiber-reinforced granules with a length of 10 to 100 mm
and a thickness of 0.1 to 50 mm with fiber~ with a length
of 10 to 100 mm a~d a thickness of 5 to 30 ~m are drawn
in gently, that iB to Ray without mechanical comminution,
into the pla_tication part of the device, are plastlcated
with minimum shear stre~sing and are di~charged in a
preformed state after the plastication. Since the dsvice
ha~ no dead spot~, thermal damage to the plasticated
material iR avoided.
The invention i~ explained in greater detail below with
reference to the figures, in which
Figure 1 ~how~ a lateral, partly ~eetional view of the
device during filling with material and
Figure 2 ~hows the device according to Figure 1 during
di~charge of the plasticated material.
The device for plastication consi~ts of a plastication
barrel 1, in th~ conical feed part 2 and cylindrical
discharge part 5 of which a pla~tication s¢rew 3 i~
arranged. The device may be mounted 80 aB to be pivot-
able, vertically, horizo~tally or perpe~dicularly to the
~crew axi~, a~out the axis 10. On the discharge part 5,
thexe is axranged a shaping die 8 which i~ ~ollow~d by a
cloaure el~mont 9. The clo~ure element 9 may comprise a
guillotlne knife. The p}a~tication screw 3 i~
rotationally driven by means of dri~e 7 on which an
apparatu~ 6 for the axial di placement o$ the c~rew 3
with re~pect to the plastication barrel is arranged. The
apparatus 6, ~or example controll~bl2 hydraulic
cyli~ders, i~ ~upported together with the plasticati3
barrel 1 on a co~mon machine bed 11 or, ~s illu~trated,
is ~upported on the plastication barrel 1. The ~iber-
reinforced granules 15 pass ~ia opening 4 into the
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conical feed part 2 and from there are driven by means of
a plastication screw 3 towards the closure ~lement 9,
during which they are plasticated. During thi~ proce~ a
back pressure builds up, l~nder which the ~crew 3 yields
S in a direction opposite to the material flow direction,
as is indicated by arrow 12. After the clo~ure element 9
is opened, the screw 3 moves towards opening 16 of the
discharge part 5 (arrow 13) and discharge~ the plasti-
cated material via the Rhaping die 8. The cros3 ~ection
of the die opening may be delimited by any contour,
depending on what ~hape thP molding i8 intended to have.
4 indicates a temperature-control apparatu~ (heating or
cooling apparatus) for the plastication barrel. 17
indicates a support for the closure element 9, and 18
indicates a hydraulic drive apparatus for said closure
element 9.
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