Medium-density fiberboard, or MDF, is an engineered wood product composed of recycled hardwood or softwood fibers, which are mixed with waxes and resins, and fused together with pressure and heat.
It’s a popular choice for furniture makers and builders around the world thanks to its durability, versatility, compatibility with paints and coatings and its low cost. MDF is used in a wide variety of wood furniture such as bookshelves, wardrobes, cabinetry, as well as fixtures like trims and moldings.
Although MDF has seen advances in chemistry to improve its durability and strength capabilities, some challenges remain. Due to the thermosetting resins that are currently used in its manufacturing, design capabilities are limited to simple, straightforward patterns.
Now, thanks to advances in resin technologies, that can change. acForm® from BASF is a new thermoformable resin that provides post-moldability and surface structuring, allowing manufacturers and designers to create intricate designs in vastly shorter timeframes, amongst a host of other benefits.
Thermoformable vs thermosetting
The vast majority of MDF on the market today makes use of thermosetting resins to provide structural integrity and resistance properties. Although effective, board manufacturers must use a router that removes material to apply patterns and designs into the board, which is time-consuming and exposes wood fibers.
MDF itself is cheap to produce, but adding designs can greatly increase costs, as it can take upwards of 10 to 20 minutes to route each panel, depending on the design.
“This is a time-consuming process, and designs with more complexity take longer on the machine, which adds to the cost and is why you currently don’t see much more than basic squares, rectangles, and the occasional curve on MDF-based products,” says Eric Lawson, New Business Development Manager at BASF. “Designs can take from a few minutes to several days depending on the complexity, and anything that takes longer is going to command a hefty price to pay for the lost productivity on a machine that could produce many simple design pieces in the same amount of time.”
Thermoformable resins, like acForm, can help solve this issue. Instead of a router, manufacturers can imprint intricate and complex designs in one-tenth the time on 3D moldable fiberboards (3MF) made with acForm using standard furniture molders’ equipment.
“You can now create a design in a metal plate or roller, which can be heated and used to emboss the design into a thermoformable panel rather than routing it,” says Lawson. “The complexity of the design, therefore, does not affect the time required to produce it. You can press a simple design in two minutes for example, or an infinitely more complex design in the same two minutes.”
Due to the specific binder-fiber composition, 3MF allows all three spatial axes to be formed at the same time, letting molders create sophisticated, highly structured, or curved components in short molding cycle times.
Who has the time?
The time savings that this technology can provide should not be understated. A design that may take upwards of 20 minutes for a CNC router to cut into a standard thermoset board may take only around two minutes to be pressed into a thermoformed board made with acForm.
Thermoformable boards also offer another advantage: because the design is being pressed into the board instead of being cut out, the design is imprinted cleanly into the board without exposing the wood fiber ends underneath.
“Those wood fibers, their role in the tree was to transport liquid water and nutrients for the tree, so in a manufactured wood product they will transfer paint the same way,” says Lawson. “That means it could be tougher to paint that surface after you're done, and it usually requires more than one coat.”
The improved smoothness the thermoforming process provides makes it easier to apply paints and coatings, and allows for improved properties for standard finishing technologies, such as lacquering or powder coatings.
Additionally, acForm can be used in conjunction with other resins. Applying acForm alongside a traditional resin can provide thermoformability along with increased water resistance or bond strength for more demanding applications.
The resins used in traditional MDF boards typically include urea formaldehyde, a solid chemical composed of a mixture of formaldehyde and urea, and additional formaldehyde is sometimes added to strengthen the bond.
The formaldehyde trapped in MDF is slowly emitted as a gas for months or years after it’s manufactured, posing a health and safety concern for both manufacturers and end-users, as prolonged exposure can lead to cancer and other health issues.
With no added formaldehyde and low VOC levels, acForm helps to reduce this issue, therefore providing a safer working environment for both board producers and molders, and OEMs.
“Thermoforming isn’t a chemical reaction that's going on in the board, it's more of a melting that's happening in the MDF producer's press,” says Lawson. “It doesn't give off any VOCs once it's in the final panel.”
Finally, BASF offers the possibility of producing acForm based on the biomass balance approach, offsetting 100% of the fossil fuel based raw material with bio-based raw material.
3MF and the future of design
With its ability to change the way board manufacturers and molders create and design moldable wood fiberboards, acForm represents a gamechanger in the industry.
At the “Haus der Wirtschaft” in Stuttgart, Germany, BASF was honored with the materialPREIS 2018 award by the raumPROBE material library for 3D moldable wood fiberboards manufactured with acForm.
It ranked first in the category “Process” for providing the furniture and interior design industry with a storage-stable composite that can be processed via hot molding.
“Because of what it can open up in terms of design, I think very soon you will start seeing intricate furniture fronts, cabinet doors, moldings and much more with this technology,” says Lawson. “It's so versatile that I could foresee having blank panels sitting in your local hardware store with an embossing press there, ready to quickly give you the design you want.”
“It's not just squares and rectangles with a few curves anymore. It's anything you can think of.”
acForm is available now for trial purposes in North America.
Interested in trying acForm for yourself? Click Here