Frequently Asked Questions How can the vacuum pouch be cleaned? The surface of the vacuum pouch is glue-repellent. For further protection, however, the
segments of the work piece where glue might leak from should be covered
with tape. Another possibility is to put the entire work piece inside a
protective foil (this is especially important when using PU glues). In
addition to this, the surface of the vacuum mat can also be coated with
a glue release agent (as used in veneer presses). When the pouch is
soiled with glue, it is usually enough to crumple it, which will get
the dried-up glue to break and fall out.
What is the operating life of the vacuum pouch? The vacuum pouch
consists of a highly resistant fabric (tear-proof synthetic rubber with
vulcanized fabric inserts, ca. 20% elongation), so that sharp-edged
wood parts do not pose any problems. However, to ensure the protection
of the pouch, sharp tips and edges of the work pieces should be
covered (for example with felt). Sharp-edged plastic boards and iron
parts should be used with caution. Do not expose the pouch to direct
sunlight or chemical solvents.
What happens in case the pouch tears? The pouch can patched with
a repair kit that can be ordered. The process of repairing the pouch
is similar to the patching of a bicyle wheel's tube.
Is the vacuum pump automatically turned off when the required pressure is reached? No.
The pump remains turned on for the entire duration of the pressing cycle. During
this time, it constantly removes moisture from the interior of the
press, which facilitates the drying of the glue. The pump's surface
will heat up, but this merely indicates that it has reached its
operating temperature.
Is the size of the vacuum pump sufficient? In most case, the vacuum
pump TF 8 will suffice. For particularly large templates (and with
quick-setting glue) it is recommended to use a second vacuum pump,
which is turned on only until the ideal pressure has been reached.
During the drying cycle, the second pump is turned off and the suction
line is blocked (this helps saving energy.
How high is the ultimate pressure? The ultimate pressure is
approximately 8 t/m². When using large profiles it is important to make
sure that the profile can sustain this high pressure from all sides.
Is it possible to veneer hollow profiles? There are restrictions for
the veneering of hollow profiles. There must be enough cushion surface
to fill the hollow profile (this can be achieved by slightly pulling
the pouch together). If necessary, the pressing cycle can be
supported by using a second, external, template (we will gladly provide
you with more detailed instructions). The manufacture of oblate door
fillings is not possible, since VACUFLEX can not provide enough
pressure.
Is it possible to manufacture concave shapes? Pressing concave shapes rarely yields satisfying results. If possible, you should always work with the convex shape instead.
Which radii can be layer-glued, and how thick can the wood be? As
long as the thickness of the layers is equivalent to the radius, there
are no restrictions. It is impossible, however, to manufacture
three-dimensionally formed plywood (such as the seat surfaces of
chairs).
How long does the work piece have to remain in the vacuum pouch? This
depends on the type of glue used and on the type of work piece
manufactured. Regarding the setting time of the glue, there is no
considerable difference between this method and conventional
cold-pressing methods. (Glueing of layers: 1 to 8 hours,
form-veneering: 20 - 30 minutes)
Is it possible to speed up the pressing cycle? It is possible to
influence the duration of the pressing cycle by choosing between
different types of glues, such as CHS-urea glue, or by heating the
surface with infrared heaters or quartz heaters (the cushion can be
heated up to a temperature of 80 °C).
Which material does the vacuum pouch consist of? Highly resistant nylon fabric, rubberized on both sides.
Do kinks or corrugation occur, since the SINUS stands are positioned between 20 and 25 cm apart? The final shape of the work piece results from the tension of the work piece's individual layers > the tension creates the shape. Should the layers not provide enough tension (such as Topan), supplements have to be inserted (such as HDF, MDF, etc.).
Do folds or wrinkles in the pouch result in faulty pressings? No,
since during form-veneering, a moulding is always added to the work
piece, and during form-glueing, the individual wood layers are stout
enough.
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