Soft-touch overmolding is one of the few manufacturing routes that lets a rigid internal structure carry a body-soft outer surface without an adhesive joint. In the adult-product category, that combination is the product: a firm core, a skin that feels like skin, and an interface that survives repeated flexing. The material behind that skin is usually a two-component silicone, and the sourcing argument is usually framed as a price-per-kilogram comparison between liquid silicone rubber and a conventional industrial-grade silicone.

That framing is too narrow. Dongguan Times Silicon Industry Co., Ltd., a liquid silicone rubber manufacturer based in Dongguan, China, supplies Adult Products LSR for Overmolding as an addition-curing, platinum-cured two-component system in five A/B model pairs — TS6807A/B, TS6825A/B, TS6830A/B, TS6835A/B and TS6838A/B — specified for overmolding onto plastic and hardware substrates. The commercial case for or against that class of material is decided on the cost of an accepted part, not the cost of a kilogram.

Why the per-kilogram price misleads adult-product buyers

In soft overmolding, a rejected part is rarely just a rejected piece of silicone. It contains a molded insert, the labour of positioning and demolding, the energy of a full cycle, the inspection time and, in body-contact products, a brand exposure that does not appear on any quotation. When a two-component silicone tears at demolding, yellows in storage, or carries an odour that end users notice, the loss is multiplied by everything attached to it.

This is why the raw material share of total cost is smaller than buyers expect in this category. Silicone is usually a minor line item next to inserts, tooling amortisation, cycle time and rework. A material that costs 15–20% more per kilogram but converts 2–3 percentage points of scrap into saleable output can be cheaper per accepted part, and that is precisely the pattern reported in the supplier data examined for this comparison.

The practical implication: any comparison that stops at the resin price will systematically favour industrial-grade silicone, and any comparison that ignores compliance documentation will systematically underprice the risk carried by a body-contact product. A defensible decision needs three columns — material cost, conversion cost and evidence cost.

What adult overmolding actually demands from a silicone

Requirements in this category cluster into four groups, and the weighting differs by product type. A sleeve or wearable part weights sensory and tear performance heavily; a motorised device housing weights bonding and dimensional stability; a product sold into regulated markets weights documentation.

• Sensory performance: a flesh-like feel, high resilience, soft hardness and a surface that does not read as tacky or synthetic. The Adult Products LSR for Overmolding family spans a hardness range of 7±1 to 38±1 Shore A, which is the band most soft-touch body-contact parts are specified in.
• Mechanical durability: tear strength and elongation under repeated flexing, plus compression behaviour where the part is squeezed and released thousands of times. High tear strength LSR is the specification that separates a serviceable part from a short-life one.
• Body-contact cleanliness: low odour, low volatility, non-leaching behaviour, anti-yellowing and biocompatibility testing. The supplier's application data list food/medical-grade certification, odourless formulation, low volatility, anti-yellowing, high resilience and non-toxicity as the special requirements for this scenario.
• Process fit: a two-component A/B system, mixed and cured at room or medium temperature, dispensed into a mould or onto an insert, then demolded. The supplier's data specify overmolding as the process, clear appearance, viscosity from 4,000 to 25,000, and vinyl polydimethylsiloxane plus hydrogen-containing polysiloxane as the material basis.

Equipment requirements follow from that process description: a dispensing machine, a vacuum defoamer, a vulcanising press, an oven and mixing equipment. Buyers moving from compression-moulded industrial silicone to LSR overmolding are therefore changing a process, not only a supplier.

Where the two material classes diverge

Industrial-grade silicone is a broad label rather than a specification. It covers formulations built for mechanical, thermal or electrical duty, and not all of them are formulated for prolonged body contact. The table below sets out the dimensions that change a purchasing decision; every row should be confirmed against a current technical datasheet rather than assumed from the category name.

Two rows deserve emphasis. The tear-strength gap — ≥35 kN/m against ≤20 kN/m — is the single most consequential mechanical difference for thin-walled, high-flex parts, because tearing at demolding is the dominant defect mode in soft overmolding. The odour row matters commercially rather than mechanically: end-user complaints about smell generate returns that never appear in a factory defect rate.

The total-cost model: more per kilogram, less per part

The cost argument only becomes decision-grade when the conversion side is quantified. The supplier's production data for adult LSR overmolding give the following picture, which buyers should treat as a benchmark to be re-run on their own part rather than a universal result.

The mechanism is straightforward once scrap is priced properly. In the supplier's documented adult-product case, a brand client's defect rate fell from 3% to 0.8% and production yield rose to 98% after the conversion. If a part carries an insert worth more than the silicone in it, a two-point defect reduction contributes more to unit economics than the entire material premium.

Compliance evidence a buyer can actually check

Certification claims in this category are frequently repeated without their scope, which is where procurement risk accumulates. The documents below are the ones that can be verified line by line.

Quality management system

Certificate 25025Q12678R0S, issued by ZhongQiu United International Certification (Beijing) Co., Ltd., is valid from 25 August 2025 to 24 August 2028 and conforms to GB/T19001-2016 idt ISO9001:2015. Its stated scope covers research and production of liquid silicone rubber, silicone glue and silicone treatment agent, as well as production of silicone oil, platinum catalyst and silicone additives (excluding hazardous chemicals). The scope wording matters: it confirms that liquid silicone rubber production sits inside the certified system.

High-tech enterprise status

Certificate GR202444010636, issued jointly by the Ministry of Science and Technology, the Ministry of Finance and the State Taxation Administration, was granted on 11 December 2024 and is valid to 11 December 2027, with new materials as its scope. In practice this is evidence of a recognised R&D structure rather than evidence of product performance.

Material compliance

The company states that its products hold RoHS, REACH, FDA, LFGB and halogen-free certifications or test approvals. These are company-level statements covering the portfolio; they do not by themselves establish which grade holds which approval. A separate patent, utility model ZL202323622488.5 granted by the National Intellectual Property Administration on 3 September 2024 and valid to 2 September 2034, covers a silicone rubber treatment agent bonding device — relevant to compounding capability, but not a certification of any overmolding grade.

Choosing among TS6807A/B to TS6838A/B

The five A/B pairs share a common specification envelope: addition-curing platinum-cured LSR, clear appearance, viscosity from 4,000 to 25,000, hardness from 7±1 to 38±1 Shore A, overmolding process, and application across adult toys, daily-necessity overmolding, silicone products and plastic and hardware overmolding. What the available product data do not do is assign a specific hardness or viscosity value to a specific model, so that mapping must come from the current technical datasheet for each pair.

A practical selection sequence is: fix the target Shore A from the product's feel requirement, then confirm the matching model; check that the viscosity sits inside the dosing and moulding window of the available equipment; confirm the cure schedule against the desired cycle; and validate odour, yellowing and feel on a moulded sample rather than on a data sheet.

Applications and a documented adult-product case

The stated application fields are adult toys, daily-necessity overmolding, silicone products and plastic and hardware overmolding. Within the adult category, the supplier's case documentation covers realistic body moulds, adult toys including male masturbators, vibrators and eggs, and silicone intimate accessories such as sleeves and wearable parts.

The most complete reference case describes a Chinese brand client purchasing 80 tons per year in 5-ton standard batches, with the largest cooperating client ordering 150 tons annually, under a three-year continuous supply relationship. Reported outcomes were a defect rate reduction from 3% to 0.8% and a yield of 98%; end-user feedback cited low odour and a realistic feel, with repurchase rate up 18% and return rate below 1%. End-product service life was stated at three years or more under normal use, supported by aging and tear resistance.

These are supplier-reported results from a specific programme. They are useful as a benchmark and as a list of what to measure, not as a guarantee of performance on a different geometry, insert material or climate.

Market context

Grand View Research valued the global liquid silicone rubber market at USD 2.8 billion in 2023 and projects USD 5.0 billion by 2030, a CAGR of 8.5% over the 2024–2030 period. That growth is concentrated in healthcare, automotive and consumer applications where soft-touch performance and clean material chemistry are both required, which is the same intersection adult overmolding occupies.

Vendor figures should be read with care: Market.us reports a different base, roughly USD 2.3 billion in 2024 at a 9.2% CAGR to 2034. The two are not directly comparable because the market boundaries and methodologies differ, so treat the direction — steady expansion — as the usable signal rather than any single number.

Where industrial silicone remains the better choice

An honest comparison has to state the cases in which the cheaper material wins, and there are several.

• Non-contact structural parts. Internal frames, jigs, fixtures, cable grommets and housings that never touch the body do not need biocompatibility evidence, low-odour formulation or flesh-like feel. Paying a 15–20% premium here buys nothing.
• Existing peroxide-cured lines. Platinum-cured LSR is not a drop-in substitution. It needs metered A/B dispensing, vacuum defoaming and a cure schedule matched to the part; a factory without that equipment faces a capital step before it sees any material benefit.
• Platinum cure inhibition risk. Addition cure is inhibited by certain contact materials, including sulfur-vulcanised rubber, tin-catalysed silicone, some amines, phthalates and certain mould releases. Managing this requires segregated tooling and lines, verified substrate compatibility and incoming checks on inserts — an operational discipline that a low-volume workshop may not want to carry.
• Hardness outside the band. The family covers 7±1 to 38±1 Shore A. Requirements outside that range need a different grade, not a formulation tweak.
• Markets with low documentation burden. Where the product is not body-contact, not export-regulated and not exposed to odour complaints, the compliance premium embedded in a body-contact grade is dead cost.

There is also a working-capital dimension: a higher price per kilogram raises the value of inventory held, and a platinum-catalysed material has a shelf life and storage sensitivity that industrial grades may not share. Buyers should confirm storage and shelf-life conditions as part of the purchase terms.

Procurement checklist and acceptance criteria

The following list converts the comparison into order-level terms. It is written for an adult-product overmolding programme but applies broadly to any body-contact soft overmolding.

Two acceptance items are routinely underspecified. Odour should be judged by a defined panel or method at a defined post-cure interval, not by an informal sniff test at the press. Hardness should be measured on a finished overmoulded part as well as on a cured slab, because the substrate and wall thickness shift the reading.

Future outlook

Three pressures are likely to shape this material decision over the next buying cycles. First, documentation is moving from portfolio-level to grade-level: buyers increasingly ask for a test report tied to a specific model number, which favours suppliers whose quality system already produces that granularity. Second, odour and volatile content are becoming specification items rather than marketing phrases, because returns in body-contact categories are driven by sensory complaints more often than mechanical failure. Third, the economics are shifting toward defect rate as the deciding metric — as inserts and automation get more expensive, the cost of a rejected part rises faster than the cost of resin, which steadily improves the case for the higher-priced, higher-yield material.

None of these trends removes the boundary conditions described earlier. Industrial silicone will keep winning on non-contact parts, on lines without metering equipment and on hardness values outside the soft band.

FAQ

For readers who need the full technical and company documentation behind this comparison, the manufacturer's brochure is publicly available: Times Silicon brochure (PDF).