H105 Heat-Curing Silicone Ink

Why is ink adhesion difficult on silicone rubber?

Check the exact silicone formulation, molded-part condition, contamination or mold-release residue, and ink compatibility. Catalyst preparation and the complete heat-curing process must also match the selected silicone ink.

Why does ordinary plastic ink peel off silicone?

Compatibility with a plastic does not establish compatibility with silicone rubber. Evaluate a system documented for the actual silicone compound and validate its catalyst and curing process on finished parts.

Why can an ink work on one silicone part but fail on another?

Silicone formulations, surface conditions and part geometries can differ. A successful test on one component does not qualify every silicone product.

Does every silicone rubber use the same printing ink?

No universal recommendation applies. Identify the actual compound, printing method, curing capability and required performance before selecting the ink.

What ink is suitable for silicone-rubber printing?

Evaluate an ink documented for the actual silicone material. Hongsheng H105 is intended for compatible high-temperature vulcanized silicone-rubber products requiring catalyst addition and heat curing.

Can H105 be screen printed or pad printed?

The H105 TDS confirms both screen printing and pad printing on compatible silicone-rubber products. Validate transfer, artwork, catalyst preparation, flash-off and curing on the actual part.

Can ordinary rubber ink be used on silicone?

Do not infer silicone compatibility from conventional rubber applications. The ink must be evaluated specifically for the silicone compound and required cure.

What should be checked before choosing silicone ink?

Confirm the exact substrate, printing method, catalyst process, baking capability, adhesion, flexibility and required resistance. H105 is appropriate only where those conditions can be validated.

Why does H105 require catalyst?

H105 is a catalyst-assisted heat-curing system. Its documented adhesion and durability depend on catalyst addition followed by the specified heat-curing process.

How much catalyst should be added?

Prepare only the required amount of ink, add 3% catalyst before printing, and mix thoroughly and evenly. The TDS does not identify a catalyst trade name or specify an alternative addition rate.

Can catalyst be added to the original ink container?

No. The TDS instructs users to prepare a working quantity and not add catalyst directly to the original ink container.

How long can prepared H105 ink be used?

Use the prepared ink within approximately four hours after mixing in the catalyst, as stated in the TDS.

How should a print run be organized around pot life?

Prepare quantities that can be used within the documented working time and record the mixing time. Keep the catalyst-mixed working batch separate from the original ink.

Can extra thinner extend the stated pot life?

The H105 source does not document a way to extend pot life. Do not treat viscosity adjustment as proof that a batch remains suitable beyond the stated working time.

Which thinner is specified for H105?

Use only odorless kerosene. The documented addition is approximately 2–5%, adjusted to viscosity, artwork, printing method and operating conditions.

Can 783 thinner or cyclohexanone be used?

No. The H105 TDS explicitly excludes 783 thinner and cyclohexanone. Thinners recommended for other Hongsheng inks must not be substituted automatically.

What should be checked when adjusting printability?

Review the approved thinner, addition amount, viscosity, artwork and screen or pad transfer. Keep the catalyst mixing and curing procedure consistent during evaluation.

How long should a printed part stand before oven curing?

Allow 5–10 minutes for solvent flash-off before oven curing. Confirm sufficient evaporation on the actual part and under the production conditions.

Why can bubbles appear after baking?

The TDS identifies inadequate flash-off as a possible cause of bubbles in the cured ink film. Check the delay before baking and whether the solvent has sufficiently evaporated.

Does flash-off replace heat curing?

No. Flash-off allows thinner to evaporate before the catalyst-assisted heat-curing stage; it does not establish a complete cure.

What temperature and time does H105 require?

After flash-off, oven cure at an actual measured temperature of 160–180°C for 8–10 minutes. Verify the schedule on the actual silicone compound and part geometry before production.

Is the oven setting enough to confirm the cure?

The TDS specifies actual measured temperature. Confirm the effective curing conditions experienced by the printed parts rather than relying only on the oven setting.

Can H105 be treated as an air-drying ink?

No. The documented process requires catalyst addition and heat curing. A dry-looking surface after standing does not confirm that the ink has cured.

What should be checked if a baked print peels?

Review the exact silicone, surface contamination or mold-release residue, catalyst addition and mixing, elapsed pot life, approved thinner, flash-off, actual curing temperature and time, and possible catalyst-poisoning contact.

Does putting the part in an oven prove complete curing?

No. Check the measured conditions and validated schedule for the actual compound and geometry. Baking alone does not establish correct catalyst preparation or compatibility.

How should a suspected adhesion problem be evaluated?

Complete the documented process on representative finished parts, then evaluate adhesion using the required test. Review the failed process conditions with Hongsheng before changing the formulation or cure.

What does the H105 TDS say about catalyst poisoning?

Prevent the original ink from contacting reactive materials containing nitrogen, sulfur, phosphorus or other catalyst-poisoning substances, because they may interfere with curing.

What should be reviewed if curing is inconsistent?

Review materials that contact the ink and the handling process for possible contamination, alongside catalyst mixing, pot life and measured curing conditions.

Can extra catalyst or longer baking be assumed to fix contamination?

The TDS does not provide such a remedy. Identify the contact source and obtain technical evaluation instead of assuming an unverified adjustment will restore curing.

What is the difference between adhesion and flexibility?

Adhesion concerns the ink film remaining attached to silicone. Flexibility concerns its response when the printed part bends. Both should be evaluated after the required cure.

Does passing a tape test establish bending performance?

No. H105 documents adhesion and a separate bending test. Validate both against the actual part's required movement and acceptance criteria.

What flexibility result is documented?

No cracking or peeling was observed in the documented bending test. The TDS does not specify a bend angle, stretch percentage or cycle count.

How should the three requirements be validated?

Complete catalyst-assisted heat curing, then test adhesion, alcohol resistance and abrasion separately on the actual finished part using the customer's acceptance criteria.

Does the TDS specify alcohol or abrasion rub counts?

No. It reports no visible change in an alcohol rubbing test and no ink removal in a manual rubbing test. It does not document a load or rub count for either result.

Are curing temperature and heat resistance the same specification?

No. The 160–180°C for 8–10 minutes condition is the production curing process. The separate heat-resistance reference reports no visible change at 150°C for one hour.

Does the curing temperature establish a continuous service rating?

No. Neither the curing schedule nor the one-hour reference establishes continuous service life at that temperature. Evaluate the actual end-use temperature and exposure requirement separately.

These are H105 internal reference results, not guarantees for every silicone compound. Validate the actual substrate, catalyst preparation, printing, complete cure and customer-specific requirements before production.

1. 1
   Identify the silicone and finished part

   Confirm the actual compound, molded condition, geometry and required performance.

2. 2
   Check surface and ink compatibility

   Review contamination, mold-release residue and results on representative silicone components.

3. 3
   Prepare catalyst correctly

   Add 3% catalyst to a working quantity and mix thoroughly and evenly.

4. 4
   Track the working time

   Use prepared ink within approximately four hours; keep it out of the original container.

5. 5
   Use the specified thinner

   Use only odorless kerosene, approximately 2–5%, adjusted to the documented process factors.

6. 6
   Confirm printing and flash-off

   Review screen or pad transfer and allow 5–10 minutes of sufficient solvent evaporation before baking.

7. 7
   Review poisoning risks

   Prevent contact with the catalyst-poisoning substances identified in the TDS.

8. 8
   Verify actual curing conditions

   Measure 160–180°C for 8–10 minutes and validate the schedule for the compound and part geometry.

9. 9
   Test the cured print

   Evaluate adhesion, flexibility, alcohol, abrasion and other required resistance properties separately.

10. 10
    Confirm the application with Hongsheng

    Use H105 only where the silicone, catalyst and heat-curing process meet the validated requirements.