PolyJet 3D Printing Design Guide: Agilus Soft Glue Parts

PolyJet works like an inkjet printer that prints resin instead of ink. A print head travels across the build tray and deposits tiny droplets of photopolymer, then a UV lamp cures them into a solid layer. The tray drops by the layer height and the head passes again. Layer heights of 0.014 mm to 0.028 mm are normal, which is why thin walls and small text come out sharp with almost no visible stair-stepping.

Because the head can switch resins mid-pass, one build can hold rigid, transparent and rubber-like sections at once. That is what makes a 3d printing design polyjet workflow attractive: a single job can produce a hard housing with a soft grip band already bonded to it. No assembly step, no adhesive.

Support material is jetted at the same time and removed later, by hand or with a water jet. This lets the process build overhangs and internal channels that would need extra support structures in other resin systems. The trade-off is surface finish on supported faces, which stays matte after removal.

Parts come off the tray with a gel-like residue. Cleaning and post-curing take time, and soft grades stay slightly tacky for a while. Plan for that if the part will be handled during assembly.

Agilus30 is a rubber-like photopolymer available in a few hardness grades. Shore A values in the 30 to 40 range feel like a soft silicone gasket; higher grades feel closer to a stiff shoe sole. Pick the grade by how the part will be loaded, not by how it looks in a render.

A thin Agilus wall deforms under light finger pressure, while the same material at 3 mm feels firm. Geometry and hardness work together, so a designer who wants a soft button can often use a harder grade and a thinner wall instead of a very soft grade.

Agilus bonds to rigid PolyJet resins during the build, so an overmold does not need primer or mechanical interlocks. The bond is chemical, formed while both materials cure. That is a real advantage over molding a rubber grip onto a plastic shell.

Where Agilus disappoints: it creeps under sustained load, it absorbs moisture slowly, and it does not survive repeated flexing like a cast polyurethane. Treat printed soft parts as prototypes or low-run production, not as long-life seals.

Keep Agilus walls at 1.2 mm or thicker. Below that, the rubber-like material tears easily at the layer lines and the part can distort while the support is being removed. Walls from 1.5 mm to 3 mm hold shape and still flex.

Rigid resin walls can go thinner, down to about 0.5 mm on a flat panel, but only if the panel is supported on both ends. Free-standing thin fins warp. Add a radius at the base of any wall under 1 mm.

Embossed text and logos should sit at 0.4 mm minimum height, and recessed text at 0.4 mm minimum depth. Below that the detail fills in. Small holes print clean down to about 0.5 mm diameter; anything smaller closes up.

Sharp internal corners concentrate stress in soft material. Use a fillet of at least half the wall thickness at every inside corner. This is the single cheapest change that extends the life of a flexing part.

PolyJet holds about ±0.1 mm on a well-oriented feature, and ±0.2 mm is a safer planning number across a full build tray. Soft Agilus parts are harder to hold than rigid ones because they compress during measurement. Measure them with light contact or with an optical system.

Moving joints need clearance. A rigid pin in a rigid hole wants 0.15 mm to 0.2 mm of diametral clearance. A rigid pin in an Agilus hole can run tighter, around 0.1 mm, because the rubber gives, but it will wear faster.

Snap fits in rigid resin work well with a 0.3 mm to 0.5 mm undercut and a lead-in chamfer. In Agilus, the same snap will stretch and lose preload within a few dozen cycles. Use a rigid snap and a soft pad instead.

Shrinkage is small but not zero. Long flat parts can bow, so orient the largest flat face parallel to the tray when flatness matters. If a feature is truly tolerance-critical, machine it after printing rather than fighting the process.

Support comes off by hand first, then with a water jet at moderate pressure. High pressure on an Agilus section can tear it, so keep the nozzle moving and stay off thin soft walls. Budget real time for this step; a part with internal channels can take longer to clean than to print.

After cleaning, parts are post-cured under UV. Skipping this leaves the surface tacky and the material weaker. Soft grades stay slightly sticky even after curing, so a light dusting of talc or a matte clear coat helps if the part will be handled.

Sanding works on rigid resin and poorly on Agilus, which smears instead of cutting. If a soft surface must be matte, ask for a matte finish straight from the printer rather than planning to sand it.

Painting and dyeing are options on rigid sections. Mask soft areas carefully, since solvent-based paint attacks the rubber-like surface and leaves it permanently soft and dull.

PolyJet is a prototyping and low-volume process. Material cost per part stays high, and there is no real economy of scale. A run of 200 small brackets usually costs less in molded plastic or machined aluminum.

Soft parts under constant compression, such as a seal that must hold pressure for months, will relax and leak. Cast or molded elastomer is the correct answer there.

If the final part needs to be structural, hold tight tolerances or take threads, print the geometry for fit checks and then machine the production version. We run 127 high-precision CNC machines across three plants in Dongguan and Singapore, with 16 simultaneous 5-axis centers, so a printed prototype can move into machined aluminum or stainless without a redesign.

Use the printed part to prove ergonomics, fit and assembly order. Use machining to prove the final material. Keeping those two jobs separate saves money on both.