Melamine Press

Melamine compound is cured under pressure in a heated mould. Because it is a thermoset, a cured part cannot be remelted: if there is a fault the part is scrap, there is no second chance. What determines quality is therefore not mechanical force but thermal discipline — the same temperature in every zone, the same time in every cycle.

The mould is heated zone by zone and the volatiles formed in the compound are vented by degassing steps. If venting falls short, blisters and porosity are left on the surface; on work such as tableware, where a glossy, pore-free surface is required, that is scrap outright. With the optional SCADA package, cure temperatures and dwell times under pressure are recorded on a cycle-by-cycle basis.

Besides tableware, the same family also presses resin-based moulding compounds. The toilet seat is the typical example: a large, asymmetric and thick part. In the two-daylight press arrangement two moulds work one above the other in the same frame; on parts like these, where the load falls off centre, a ram that descends parallel determines the thickness and flatness of the seat.

The melamine press belongs to the same hot press family as the silicone and rubber presses; the frame and the heating infrastructure are shared, and what changes is the mould and the recipe. Platen size and stroke are dimensioned according to the part size of the job.

• Zoned mould heating with thermocouple feedback
• Venting of volatiles through the degassing cycle
• Cycle-by-cycle recording of cure temperature and time (optional SCADA)
• Two moulds working in the same frame in the two-daylight arrangement
• Platen and stroke are dimensioned according to the part of the job

When the form or the embossing does not come out, the toolmaker is blamed straight away. More often than not the die is not the cause: the press frame deflects under load and the two halves of the die no longer seat fully on each other. The share the frame has in this is usually unknown on the buyer's side, because it is written in no catalogue.

When ÖZKOÇ builds the frame as a welded construction, it joins the crossbeams and the plates BY PREPARING A WELD BEVEL. There are many companies in the sector that join without preparing a bevel; the weld then stays on the surface only. Once the bevel is prepared, the weld penetrates the cross-section and the frame resists deflection under load.

This holds for every frame type, monoblock or column-type — it is not an option that depends on the type of press, it is ÖZKOÇ's manufacturing discipline.

• Crossbeams and support plates are joined with a prepared weld bevel.
• The weld does not stay on the surface, it penetrates the cross-section; the frame does not deflect under load.
• The same discipline is applied whether the frame is monoblock or column-type.

On wide and asymmetric parts the load bears on one corner of the ram; the ram comes down slightly tilted and one corner of the part turns out thicker than the other. The result: excess material, uneven strength, unnecessary heat and cycle time.

In the ram parallelism system designed by ÖZKOÇ itself, four counter-pressure cylinders bring the ram down parallel to the lower plate. The difference in thickness between the corners drops to a minimum; material is saved, and the homogeneity of the part keeps the strength where it is wanted.

The same arrangement works in cutting as well: at the instant the shear occurs, the counter-pressure cylinders absorb the shock, maintain parallelism and extend the life of the cutting die.

• Four counter-pressure cylinders bring the ram down parallel to the lower plate.
• On a wide and asymmetric part the difference in thickness between the corners drops to a minimum.
• Material savings + homogeneous strength.
• In cutting it absorbs the shock and extends die life.