Heißkanaldüsen Typ SLT/-DLT Customer information

1.5. 14
iA
Heißkanaldüsen Typ SLT/-DLT Customer information
Hot runner technology for medical
products: Precision millions of times
Implementation of tandem technology requires an
injection molding machine with a relatively high
installation height of the mold and adapted
programming. B.Braun decided to use a machine of the
type Engel 200/90 V Electric with an electrical injection
unit.
“The hot runner system is the highlight of the tandem
mold,” emphasizes Stefan Moser. “This system does not
only guarantee an equal filling of the cavities on both
sides of the mold, but also a faultless gate point at the
protective caps.” “Because of the high number of cavities
24+48 in the tandem mold, we first focused on a 24+48drop
hot runner system with individually controlled open
single nozzles,” says Walter Ehlert, responsible for
consulting and sale at GÜNTHER Heisskanaltechnik.
For about 20 years B.Brown has been trusting in
components provided by the company from
Frankenberg.
Picture: Open multi-tip nozzle of the type 26ZHT – all in all 24 nozzles
are installed in the two parting lines of the mold: 12 of them with two
tips each on the Mini-Spike side, and 12 of them with four tips each
on the Transofix side
Picture: Mini-Spike, a withdrawal and injection spike for multi-dose
containers (above) and Transofix, a transfer device (below), each of
them with a protective cap (green color): Such a protective cap made
of polyethylene (Lupolen 3020K) barely weights 0.5g
“But it would have been too demanding and expensive to
install such a system within the planned compact mold,”
Walter Ehlert continues to explain. Since the hot runner
with multi-tip nozzles did function well in the mold in
stock, this technical alternative solution has finally come
into view.
Ehlert describes the advantages of multi-tip nozzles for
tandem production in the following way: “These nozzles
have a very small structural shape, therefore they allow
very small patterns in the mold, keeping the controlling
effort low.” However, the use of multi-tip nozzles is often
a compromise because there is only one control zone for
four gates. Therefore the user cannot control the details
of the process so well as with single nozzles. However,
with “simple” materials this feature can be compensated
for without any problems.
The concept of the hot runner system comprises twelve
open multi-tip nozzles per parting line; the ones of the
type 26ZHT18/2/67-S with two tips on the Mini-Spike
side, and the others of the type 26ZHT18/4/67-S with
four tips on the Transofix side. Valve gate technology
was originally planned only for the sprue bar. However,
since the mold was thought to work with a stiff sprue bar
which moves away when the parting line 1 opens, valve
gate technology was also provided for the injection
molding machine along with the needle valve in the
sprue bar.
For any questions, please contact our Application Engineering department at + 49 (0) 6451 5008-31 or -63.
The information is given in accordance with our present-day knowledge and is meant to provide technical background.
www.guenther-hotrunner.com
Subject to technical changes 7/12