How to fix sticky silicone baby bibs? It started with a phone call from a client last month. I had just finished morning meeting, and my cell phone was vibrating like a pile driver: “Rita, the bibs have passed the KC test 1”. It is a good thing, because this product design and development has taken us half a year. Finally, it came to this step of doing the test, and passed it.
Background
Why did a seemingly simple product take so long? Today I’ll sell a little bit of the background. Client’s Requirement.
- Save costs
- Use solid silicone process to achieve the high transparency of liquid silicone. (solid silicone and liquid silicone transparency has a certain gap)
- The bibs are ultra-thin and ultra-lightweight (weight below 50g). But customer wants the bib to achieve the effect of a heavy bib (weight usually between 90g~160g).
You can take a look at the picture below, which shows this similar bib pocket. Usually the pocket will be designed as ova for ultra lightweight bib, not like the pocket stand-up. Because that lightweight pocket may can’t hold food well.
This client really gave us a problem. You can refer to a previous article I wrote about how to develop and design a new product, and think about if you were to design it, would you be able to identify the potential risks and how would you address them
Question:silicone bibs turn Sticky
Just when I was happy, the customer then took a turn for the worse. He found that the product is very sticky, 2 bibs will stick together when stacked. After checked carefully the video from client, I hastened to pacify: “I’m sorry for this issue, but I noticed you this risk before when you insist on transparent bib but not semi-trans one whose surface is Matt and not sticky; what’s more silicone products if stored in a high temperature and humidity environment, will be aging, and thus the surface becomes sticky. Anyway, we would do our best to improve it
Solutions: how to fix sticky silicone baby Bibs
After the phone hangs up, I find the person in charge of the workshop at the first time, tell him the customer’s concerns and requirements, after checking the stock samples, found that a single bib folding will not be as sticky as the video sent by the customer, but when 2 bibs stacked together will indeed be sticky
we quickly convene a meeting to analyze the reasons for the relevant personnel to look for upgrading methods: According to our experience, usually the sticky surface of silicone products is related to the aging of the material, surface treatment, production process or additives precipitation.
After elimination, we analyzed where there was room for improvement:
1. Raw materials
– Insufficient cross-linking density of solid vapor phase adhesive, if the vulcanization time is short or the temperature is insufficient, the cross-linking reaction of silica gel is not completed, and the residual uncured components will lead to viscosity.
– Too little vulcanizing agent in the formula or uneven distribution, resulting in insufficient curing of the material.
2. Mold
Plating layers (e.g. nickel, chromium) may react slightly chemically with silica gel and change the surface properties
3. Additive precipitation
Mold release agents, which are not thoroughly removed or react with body perspiration, may form sticky residues.
We immediately proposed solutions to fix sticky silicone and proceeded to proofing:
On the production line, Li led the workers to dismantle all the molds and redo the surface treatment, plasma treatment of the molds before plating, and after plating to increase the ultrasonic cleaning steps, just like a protective coating for cell phones like a film.
The purchasing department rushed to find a more reliable raw material supplier (FDA-approved), to replace the old gas phase rubber with platinum vulcanized rubber – expensive, but the anti-aging test can carry 80 ℃ dishwasher;
Test the production temperature and vulcanization time; after production, the product is placed in the oven, baked for 1 hour / 2 hours to test the surface effect. After many attempts, we finally found a more suitable solution.
Other solutions to fix sticky silicone
However, due to the characteristics of the silicone raw materials, if improper storage or improper conditions of use, there will still be such a problem, so we recommend that the bibs sprayed with oil, which can be used to anti-dust and anti-adhesive to prolong the service life as well as to enhance the feel of the surface. However, as mentioned before, the customer requires the transparency of liquid silicone, but after spraying oil on the surface, the bibs will become translucent, in order to better explain the difference, we immediately arranged samples:
As you can imagine, the customer did not choose oil spraying in the end, so we put forward some corresponding suggestions when use it:
Cleaning and De-sticking:
– Wash gently with warm water + neutral detergent, then gently rub the surface with alcohol cotton pads (70% concentration) to remove the surface precipitates.
– Toner/cornstarch: Apply a small amount to sticky areas and wipe off to temporarily reduce stickiness (but repeat frequently).
– Or apply a thin layer of food grade petroleum jelly, let it sit for an hour and then wipe off the excess.
Attentions
-Avoid high temperature cleaning: hand wash mainly, keep away from dishwasher and boiling water.
-Dry and light storage: hang it in a ventilated place when not in use, don’t put it together with face oil.
If you ask me, a faulty product is like a child getting into trouble, and remedying it with care can save your character!
Additional Technical Citations
- For platinum-cured silicone performance:
Platinum Catalysts in Silicone Vulcanization (ScienceDirect) - For mold contamination risks:
Mold Release Agent Interactions (Rubber World)