moldable chipboard

What I’m looking for is basically smooth paper pulp (think egg carton), however after speaking with two pulp manufacturers, they cannot achieve a smooth “egg carton” with paper pulp.

Does anyone know if there is a process out there to accomplish this? Like taking a sheet of chipboard and molding it over a slight compound curve.

I’m not sure what you’re asking for. In the first paragraph you say you want a paper pulp, but in the title and second paragraph you say you want chipboard?

It’s definietly possible to mold paper pulp into 3D shapes. Maybe talk to some other manufacturers? There are way too many egg cartons and fast-foot drink trays for them all to be made by one person, so ask around.

As for molding chipboard…I’m not sure. You can bend and laminate plywood but it’s very grain-dependent, so I dunno how well chipboard would work (being full of variously shaped and oriented chunks of wood).

I’ve heard of molded MDF and particle “board” but I believe that you need a dedicated mold and press to generate enough pressure to get the same kind of density you see in the flat sheet goods. A small relief could probably be achieved on a typical MDF-type press, however.

SABA (France) had a TV enclosure back in the 90’s made from molded particle “board” but I can’t seem to find any info on it…

sorry for any confusion.

paper pulp process with chipboard smooth finish.

thanks 73lotus, i’ll investigate the molded mdf, as it is another example of the target finish.

Most egg cartons and molded paper products are made in a single sided mold. That is why the one side is smooth (relatively) and the other looks unfinished.

It is possible to mold pulp in a two sided mold. - Or to have a wire screen pressed on the exposed side to smooth it out. The amount of pulp used per piece also has an affect. (you can specifiy different weights just like sheet paper) The heavier the pulp - the stronger the product.


Semantics … a little clarification of words, perhaps?

You are using the term “chipboard” to describe a “paper” product … yes?

“Chipboard” is also a generic term that some use to describe the wood product(s); OSB (Oriented Strand Board), and MDF (Medium Density Fiberboard). “Particle Board” is another. Most are (usually) manufactured from various sizes of cellulosic fiber (wood), bonded together by an adhesive, and heat cured. They can be molded into “complex” shapes with matched-surface, closed, molds.

You may want to Google the term; “Molded Pulp”

For starters see “Thermoformed Fiber” at:

Weidmann does a heavy paperboard-like material called Maplex, that has shown some success being molded in compound shapes. PDF with some general guidelines is here:

It’s definitely possible- I own a product that fits the bill. This stuff:

It does have a bit of texture on the outside face, but you can see it’s in the mold itself (probably to help with paint adhesion). The back side has some grain because it’s a one sided mold.

Do you need the part to be made of smooth paper pulp only?
Is any coated finish allowed? If you follow the finishing process for fibreglass matting, you should get a good gloss finish.