Direct Answer

IOTA LSR 3620 Series is a no-post-cure liquid silicone rubber product. Main features include two-component 1:1 mixing ratio, excellent mold release, VOC below 0.5%, fast heat curing, and excellent mechanical properties. Applications include baby care, food contact, seals, and other injection-molded products. The curing data give: for 2 mm thickness, 90 seconds at 130°C; 45 seconds at 150°C.

Selection should not rely only on “no post-cure,” “VOC <0.5%,” or “food contact.” First confirm the specific application and contact medium, product structure and thickness, mold and release method, A/B 1:1 metering and mixing, curing temperature and time, mechanical property criteria, and the regulatory compliance and migration testing required for baby care and food contact. This article does not equate “no post-cure” with no post-treatment being needed for all thicknesses and structures, nor does it equate VOC data with food-contact compliance. IOTA can provide liquid silicone rubber raw materials and corresponding product data; the company does not provide complete formulations or formulation development services.

1. First Ask What LSR 3620 Series Is Expected to Solve

The series is used for baby care, food contact, seals, and other injection-molded products. Different applications focus on different points: baby care on safety compliance, soft feel, and durability; food contact on regulatory compliance, migration, and odor; seals on compression set, media resistance, and dimensional stability; other injection-molded products on flow, release, and molding efficiency. Selection should start with the final product, contact object, and regulatory requirements, not just “no post-cure.”

2. What to Specify in an Inquiry or Sample Request

If the customer already has a test specification, obtain the original document first. When criteria are missing, confirm them with the project owner and test laboratory before making samples, so that both sides do not discover different interpretations of “pass” after testing.

3. Check Mixing/Metering and Curing Conditions Before Discussing No Post-Cure

IOTA LSR 3620 Series uses a two-component 1:1 mixing ratio. In production, confirm metering accuracy, mixing uniformity, and workable time; metering deviation or poor mixing can affect curing, release, and mechanical properties.

The data give 90 seconds at 130°C and 45 seconds at 150°C for 2 mm thickness. These conditions correspond to a specific thickness and cannot be directly applied to thicker or more complex products. The thickest section, mold temperature, injection amount, and equipment heating efficiency all affect actual curing. “No post-cure” should be understood as the series reaching target properties under confirmed primary curing conditions; it does not mean that any thickness or equipment requires no post-treatment. Whether secondary heating or post-treatment is needed should be confirmed with the specific product and customer specification.

4. Understand Mold Release and VOC Under Specific Conditions and Test Methods

The product features state excellent mold release and VOC below 0.5%. Release performance depends on mold material, surface condition, product structure, cure degree, and whether a release agent is used; “good release” cannot be used to infer that all molds and structures need no release measures. VOC below 0.5% should be understood together with the test method, sample state, and customer limit; it cannot be directly equated with food-contact compliance or odor acceptance.

For food contact and baby care, obtain the corresponding regulatory compliance statements and necessary migration test reports, and evaluate against the customer restricted-substance list. For seals, compression set, media resistance, and dimensional stability should be tested separately, not judged only by tensile strength or hardness.

5. Typical Features Are Conditional Descriptions, Not Finished-Product Certification

The product data state fast heat curing and excellent mechanical properties, but specific hardness, tensile, tear, and elongation values are not given in this section. Ask the supplier for current batch technical data and evaluate samples made with the target product and curing conditions. Baby care and food contact applications involve safety compliance; material feature descriptions alone cannot determine final-product compliance. The final product must also be evaluated with formulation, process, additives, and contact conditions.

6. Prepare Samples in This Order Before Sending

1. Obtain the customer’s service conditions, regulatory requirements, and acceptance criteria; confirm whether “no post-cure,” VOC, food contact, and baby care requirements are targets or existing results.

2. Specify application, contact medium, product structure and thickest section, mold, A:B = 1:1 mixing/metering, curing temperature and time, and post-treatment arrangement.

3. Check the current IOTA LSR 3620 Series data, then have the user make representative samples and keep records of mixing, injection, curing, release, and post-treatment.

4. Arrange tests as agreed; keep sample identity, test conditions, observation photos, and evaluation results in the report. Before expanding use, confirm whether the samples represent actual workpieces.

IOTA/Anhui Iota Silicone Oil Co., Ltd. positions itself as a solution provider across the organosilicon industry chain and can provide liquid silicone rubber raw materials and corresponding product data. When communicating, provide the final product, contact medium, regulatory requirements, mold, and curing equipment together to facilitate candidate screening; the company does not provide complete formulations or formulation development services.

FAQ

1. Does no post-cure mean no post-treatment is needed at all?

It should not be interpreted absolutely. The series can reach target properties under confirmed primary curing conditions, but whether thicker products, complex structures, or specific compliance requirements need secondary heating or post-treatment should be confirmed with the specific product and customer specification.

2. Can 130°C/90 s or 150°C/45 s for 2 mm be directly used for thicker products?

No. Curing time varies with thickness, mold temperature, injection amount, and equipment efficiency. Confirm with the thickest section and representative samples.

3. Does VOC below 0.5% mean food-contact compliance?

No. Food-contact compliance also requires corresponding regulatory compliance statements, migration testing, and customer restricted-substance evaluation; it cannot be judged from the VOC value alone.

4. What should be noted for A:B = 1:1 mixing?

Confirm metering accuracy, mixing uniformity, and workable time. Metering deviation or poor mixing can affect curing, release, and mechanical properties.

5. If mold release is good, is a release agent unnecessary?

Not necessarily. Release performance depends on mold material, surface condition, product structure, and cure degree, and should be evaluated with the actual mold and process.

6. Can you directly recommend an LSR 3620 formulation for baby care or food contact?

First define the contact medium, service conditions, regulatory requirements, and customer specification, and obtain the corresponding compliance documents and test evidence. Final-product compliance cannot be promised based on product features alone.