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 bicycle 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 cushion?
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 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.