HyboFOAM ® Drying of foam ® foam.
Nov 8,2024
If not stored in a completely sealed aluminum foil bag, HyboFOAM® will absorb moisture from the air. Once the foam absorbs moisture, its compressive creep performance will deteriorate. Consequently, under certain temperature and pressure conditions, such as during autoclave processing, RTM (Resin Transfer Molding), or compression molding, the dimensional stability of the material will be affected. Therefore, it is essential to dry the material before use to eliminate water vapor during processing and enhance its resistance to compressive creep.
Typically, it should be heated at a rate of 2 - 3 °C per minute in an air - circulating oven at a temperature of 130 °C for a minimum of 3 hours. During this process, the sheets must be spaced at least 35 mm apart from each other. Meanwhile, the requirements for sheet placement and temperature control must be strictly adhered to. When the thickness of the sheet is greater than 25.4 mm, the drying time needs to be extended.
Heat Treatment of HyboFOAM® Foam
For processes requiring temperatures above 180°C, the material must undergo high - temperature heat treatment to improve its compressive creep resistance:
Step 1: Dry in an air - circulating oven at 135°C for at least 4 hours.
Step 2: Increase the temperature to a range between 150°C and 180°C and dry for 48 hours.
Since high - temperature heat treatment at 190°C can damage the material surface, and the material may experience dimensional accuracy changes during the drying process, machining of shaped core materials should be carried out after the high - temperature heat treatment.
Machining of HyboFOAM® Foam
Due to the rigid closed - cell structure of the foam, when using a CNC machine tool for processing, the machining process can be carried out rapidly. Moreover, unlike honeycomb materials, it does not require special equipment; common CNC devices can generally handle this task.
Fix the foam onto the CNC machining table using double - sided tape, or install a workbench with a vacuum adsorption device on the CNC machine tool. During the machining process, a vacuum dust collection device should be used to remove the dust generated during cutting.
If a steel cutting tool with a helical blade embedded with 60/72 - grit industrial diamond is used, the recommended rotational speed is 7200 - 12000 r.p.m. If a five - point, quenched NONVAR tool steel blade is used, the rotational speed should be between 2800 - 3500 r.p.m.
The feed rate can be appropriately increased to ensure a smooth machined surface of the foam. A too - slow feed rate may instead damage the machined surface of the foam.
