What printing process and material would you use?

[HomerSimpson]

I am looking for your recommendations for the ideal print process, and material for my application. I have developed a modular building block, with our current focus on interior work spaces, at home or an office. I machine them on a CNC router from various materials, 1/4" white melamine with an MDF core at the low end, to 3-ply solid bamboo at the high end. Each block is <23" wide. I want to add a product which is either canned, or customer uploaded images, which can be applied to the surface of the panel, either before or after machining. Durability, image quality (resolution, vibrancy, etc), and cost are the key parameters. My cost to add the image would ideally be under $2-$3/sq.ft, which includes the printing, material (if applicable) applied to the block surface, and my labor to apply that material.

I would outsource this to a local printer and if demand takes off, buy the equipment to do it in-house. If I do this, ideally the printer costs me less than $25K and the cost of printing is less than 75 cents per sq.ft.

Here are my thoughts as a result of my research into the options. Feel free to correct any of my statements or add your own thoughts on the best print process and material for my application.
1. UV FLATBED PRINTER: This seems like it is the best option if I exclude my cost requirement. From quotes I have received from printers, the cost is too high (these quotes vary from $6 to $80 per sq.ft.). If I buy a printer, and amortize it the cost into each job, I'm concerned that there would be long periods of time when the printer is not in use, and this may affect the printheads (nozzle clogging, replacement, etc).
2. UV ROLL PRINTER: Obviously I'd need to print on a flexible material and then stick it to my panel. Adhesive backed vinyl? Non-adhesive material that I place on my panel after I have applied an adhesive? My worry here is accurately cutting the material into the shape of my panel, and then accurately adhering it to the side of my panel so that the image is edge-to-edge on the finished product.
3. LATEX ROLL PRINTER: Ink cost can be high due to HP being the main/only vendor. Machine can sit for longer periods of time between jobs without negatively affecting heads and ink evaporation. Higher run cost due to power usage from heaters.
4. ECO-SOLVENT ROLL PRINTER: Some limitations on substrates. Can the machine sit for long periods of time between jobs?
5. SOLVENT ROLL PRINTER: Low resolution.
5. AQUEOUS WIDE FORMAT PRINTER (sheet or roll): I know the image isn't durable. Can I laminate it and then stick it onto my panel?
6. WIDE FORMAT XEROGRAPHIC PRINTER: This would be ideal if I could find one that could output a 24" wide, full color image, and then possibly laminate it, because I know these machines can sit for long periods of time between jobs.

 

[Solventinkjet]

The most effective option is the flat bed for sure. It cuts the labor of applying out completely and also the vinyl cost. But the machines are much more expensive. 23" is an unfortunate size because it's over the max of most desktop flatbeds which would be in your budget range. You'd need to get the larger full sized ones which are pretty expensive.

For pretty much all of these options you will need to laminate if you expect it to have lots of contact.

I'd rule out the aqueous options. Even laminated they will fade with even minimal sun exposure.

For all the things I do not like about the Latex, worrying about the heads clogging due to not using it often is not something to be concerned about. The other options do require more maintenance to prevent clogs. The latex's consistency does take a hit however because the heads deteriorate much quicker so you do have to keep an eye out for quality and color changes.

 

[Inks]

Melamine can be a challenging substrate for ink to adhere to. If you are going flatbed, then have the printer manufacturer or someone local that has the printer you covet test print on the melamine for adhesion. Roll to roll print and laminate may be the best bet as the inks will be protected. Most UV inks are not solvent, chemical or abrasion resistant. If the print gets dirty and someone tries to clean it you may have a problem.

 

[johnnysigns]

Melamine is tough to stick to as said above. Not sure if adhesion promotors work on that stuff with UV digital and/or if it's even possible with the product you're selling.

 

[HomerSimpson]

To clarify, I don't need to print on melamine. My likely candidate is 1/4" MDF, but any material in this price range is acceptable, and would be chosen on my ability to either print directly on it, or adhere the material I had printed on to it.

This is an image of an individual block a local printer printed directly to with a large UV flatbed. The base substrate is oriented strand board (OSB), which is very rough. Aesthetically, I wouldn't use this material.

Regarding printing on a smaller flatbed printer, that is an option, however, based on the MSRP of the ones I have found, that are 24"+, it would probably make sense to pay a bit more and get a full sized flatbed machine.

 

[HomerSimpson]

The final image, once the blocks are assembled on site by the customer, will always have gaps in it between the blocks. I don't need to zero out those gaps. I do need to ensure the image on each block has an image all the way to the edge, and is located to it within reasonable tolerances. I included a hyperlink to my website in the original post but it didn't show up very well. https://blokaloks.com/

 

[HomerSimpson]

Several panels together just after printing, before they had been assembled into blocks to be sent to the customer--just so you have an idea of what the hell it is I'm trying to do.

 

[GB2]

Here's a small format UV printer that is fairly new to the market. I don't really know much about it but it seems to fit your needs:

Xante

Xante

www.xante.com

 

[HomerSimpson]

I think UV is too expensive, whether I outsource it, or buy the equipment myself.

What if I overprint on adhesive-backed vinyl, then put it on the 4x8 MDF sheet, then machine it? This will give me perfect registration and minimize my labor.

If you think this will work, the questions are 1) which print process would you use, and 2) which material would you print on?

 

[HomerSimpson]

I'd run with latex if you want minimal investment and ease of use. You'll be able to upgrade and sell the hp off fairly easily if you find the demand for prints is strong, but you won't be sitting with a big paperweight if you find the response lacking. Material wise, you'll want long term and durable, yet not necessarily conformable. Cast material is far superior to calendared as far as life goes, thicker laminate that is still cast would be ideal, or even a poly-carbonate laminate. I have used some eclipse poly laminate that would high a lot of the imperfections on a sheet of OSB, but I don't know how well your adhesion to something like that would be without priming, especially with handling and over time. Something like MDO would be ideal, but would probably be cost prohibitive.
Ideally get HP 365 or other 300 series, run either 3m ij175 or 180 (with 3m 8520 matte laminate), arlon 6000 series or slx series (3220 matte lam), ideally utilizing a smoother board than OSB. You would need to add a laminator to mount the laminate. Additionally you'll have to worry about the edges lifting/tearing while routing, perhaps routing with the face side down, cutting most of the way through the board with a standard wood bit, then finish off with an upcut bit to pull the print into the board instead of off the board. You will obviously lose the width of the bit worth of the image by doing it this way. Other way is to get a camera registration system on your router, and print actual panel shapes spaced out, but this would generate much more waste and require much more setup and investment.

Great feedback on materials! I can get a 4x8 sheet of 1/4" MDF for $16, and it is very smooth, so I think is probably the best substrate I could use. I'll do some experimentation with this and the materials you recommended. I use a compression bit for cutting material on the router. It has a downward spiral for most of the length of the bit, which gives a clean cut on the top surface, but then it transitions to an upward spiral for the last 1/8" or so, to give a clean cut on the bottom surface, thereby 'compressing' the wood chips in the cut path. I have cut vinyl on MDF before with these and it works great.

I'm not clear on the reason for laminating the vinyl after printing. Is this purely for durability? If I laminate it, won't I be sealing in the one side of the vinyl with the adhesive, or are the materials you recommended all non-adhesive, and then I separately apply an adhesive to the MDF first?

 

[SignMeUpGraphics]

The laminate only covers the print side of the vinyl, the existing adhesive side will still be used to adhere the graphic to the substrate.
Lamination will add durability and resistance to scratching and provide additional UV protection to make the prints last longer before fading.

 

[HomerSimpson]

What is a good estimate for a 4 color, 100% coverage, per square foot, only for the ink for a latex printer, say one of the HP 300 series (or any for which you have data)?

 

[BigNate]

print whole panels on a flatbed printer, cut into shapes with a flatbed laser engraver (almost no kerf, so no worry about gaps.)