Generally, the surface of silicone products is typically quite sticky. Sometimes this can present problems in an end user’s application, especially when buying glossy silicone products, such as silicone tubes, custom silicone molds, silicone sheets, etc. However, there are several ways to reduce this problem.
Powder with Talcum
The simplest way is through the addition of talcum powder, wiping this uniformly across the product’s surface. Silicone swim caps with talcum are very effective, it is easier to wear and take off the silicone cap after powder, and talc can be washed off.
Spray hand-feeling electrostatic oil on the surface
It is a common method to spray hand-feeling electrostatic oil on the surface. In general, the silicone products we have used for a long time will be sprayed with hand-feeling electrostatic oil, such as silicone phone cases, silicone protective covers, silicone vibrator and silicone facial cleansers, etc., this process will not affect the use efficacy, and will not cause harm to the body skin, so this process in the silicone products industry is more widely used.
This process is mainly to spray a layer of hand-feeling oil on the surface of the product to enhance the surface feel of the product and the isolation layer. Because it has a certain adhesion, there will be no demoulding after baking at high temperature, so it is adopted by many consumers, however, the main problem with this kind of process is that it is a little difficult to go through some strict environmental monitoring and certification. Because the ink materials do not meet the environmental requirements.
Produce with anti-static silicone rubber material
In addition to spray handle oil, silicone rubber manufacturers can also use materials to solve the problem of dust, that is, the selection of anti-static silicone rubber processing, because dust-proof and anti-static silicone rubber is a two-component silicone material, it can be cured at room temperature or at elevated temperature. It is not limited by the shape and thickness of the silicone products which can endure high temperature for a long time. It can be deeply cured, to achieve the effect of non-stick dust.
Anti-static silicone rubber has excellent resistance function, usually after high-temperature vulcanization of the static silicone rubber product surface resistance of 106-109Ω, but also through customer demand modulation to higher performance. Compare with the gas-phase silicone, they are no different. so it is suitable for molding and extrusion and liquid injection molding process and so on, usually, this kind of silicone can be used for silicone suction cup, silicone medical hose, and food-grade silicone products, etc.
Made by Matte Surface mold
Silicone products made by the matte surface mold are not active dust absorption. Matte surface silicone is relatively rough to touch, its advantage is effectively isolated from the dust absorption.
How to do if the silicone products accidentally get a lot of dust?
The slight dust can be wiped with a dust-free cloth, and the dust on the surface of the product can be removed.
The more serious dirt and dust can be wiped with white electric oil, or directly soaked in white electric oil liquid and wiped with a clean dust-free cloth.
For sealing and protection products, Fluorosilicone is suitable for use in aerospace, automobile, electromechanical, electronic, mechanical, and architectural fields, it can be used in kerosene at-55 °C ~ 220 °C and in steam and open flame at 150 °C, and in the strength of more than 100 kg under the pressure of heat resistance, oil resistance, ozone, and other harsh environment continued to use.
Fluorosilicone is called trifluoro propyl methyl polysiloxane, also known as special silicone rubber, its main material is carbon tetrafluoride and ethylene which combine trimethyl trifluoro propylcyclo trisiloxane, and an amount of tetramethyl tetravinyl ring, tetra-siloxane, and a small amount of blocking agent was cured and mixed under the catalyst. Compared with ordinary silicone rubber, the impact properties are improved effectively.
Compared with ordinary silicone products, the outstanding feature of Fluorosilicone is performance and service life. The normal service life of ordinary silica gel products, such as reaching the bearing capacity of Fluorosilicone rubber, will accelerate the aging capacity, the tensile strength will drop, the deformation will be larger, and so on. Silicone elastomers are also known as silicone rubbers which are composed of silicon, carbon, hydrogen, and oxygen. They are non-reactive, stable, and resistant to extreme environments and temperatures from −55–300°C (−67–572°F). Fluorosilicone also has these characteristics.
Fluorosilicone rubber distinguishes itself from silicone because it also contains additional beneficial properties common to fluorocarbons. The addition of these compounds enhances FVMQ’s capacity to resist solvents, fuel, and oil. Fluorosilicone has a slightly lower maximum service temperature hot air resistance than ordinary silicone.
The important features of Fluorosilicone products are as follows:
Resistance to oil, solvents, and chemicals
Compared with methyl vinyl silicone rubber, Fluorosilicone has excellent oil resistance, solvent resistance, and chemical resistance, and good oil resistance and solvent resistance even compared with fluoro rubber. It can be said that Fluorosilicone rubber is the only elastomer that is resistant to non-polar medium at-68 °C ~ 232 °C. The resistance of Fluorosilicone to gasoline containing methanol is also good. Even in the gasoline/methanol mixed material, the hardness, tensile strength, and volume of the vulcanizate have little change, the physical properties have hardly changed after 500h long time immersion testing.
Heat resistance
The high-temperature decomposition of Fluorosilicone is the same as that of ordinary silicone, i. e. side-chain oxidation, main chain fracture, side-chain thermal decomposition, and various compound reactions. As the decomposition products can also cause the main chain fracture, so the heat resistance, usually worse than ordinary silicone rubber, at 200 °C temperature has begun oxidation aging. However, by adding a small number of heat stabilizers such as iron, titanium, and rare earth oxides, it can be improved remarkably and has enough heat resistance even at 250 °C. The influence of temperature on Fluorosilicone is greater than that of silicone but less than that of fluoro rubber. The service life of Fluorosilicone rubber was also studied at 150 °C × 2000H, 175 °C × 5000H and 200 °C × 4000H, the results were second only to that of methyl vinyl silicone rubber.
Cold tolerance
Fluorosilicone and ordinary silicone products are good low-temperature performance. Because Fluorosilicone rubber is a linear polymer with soft SI-O as the main chain, its low-temperature property is better than that Fluororubber with C-C as the main chain. Among them, Fluorosilicone (LS-2370U) has better low-temperature characteristics, the brittleness temperature reaches -89 °C, and the general Fluororubber is -30 °C.
Electrical properties, radiation resistance
The electrical properties of Fluorosilicone are similar to those of ordinary silicone rubber, but its special value is that it changes little under harsh conditions such as high temperature, low temperature, humidity, oil, solvent, chemicals, ozone, and so on. The radiation resistance of Fluorosilicone is not outstanding, but the radiation aging resistance is better than methyl vinyl silicone rubber.
Physical and mechanical properties
Fluorosilicone rubber and ordinary silicone rubber, vulcanizate mechanical strength (especially tear strength) is relatively low. Therefore, improving the strength of Fluorosilicone rubber is also an important research topic.
Other features
Fluorosilicone rubber weather aging resistance is very good, even after exposure for 5 years, still maintain good performance. Ozone is one of the most common gases produced during the aging of elastomers, but no cracks or cracks are found in Fluorosilicone rubber by dynamic or static tests. In addition, Fluorosilicone rubber mold resistance, physiological inertia, an anticoagulant is also very good.
PVC sheet, PVC panel, PVC wall panel, PVC cable, PVC roll, PVC square tubing, PVC angle trim, etc. Silicone molding resin, silicone shoe cover, custom silicone molds, etc. Silicone and PVC materials are widely used in building materials, industrial products, daily necessities, pipes, wires and cables, packaging films, foaming materials, sealing materials, fibers, etc. From the appearance, it is hard to tell PVC or silicone products, but they are different materials and have different characteristics.
Silicone
Silicone belongs to rubber material. Silicone is mainly composed of organic silicon and silicon atoms, and the main material is siloxane, which is insoluble. The silicone rubber products are mainly made of silicone oil, siloxane, silicone resin, and silane coupling agent. Silicone is the safest material in the rubber industry now, it is a kind of environment-friendly chemical material.
Compared to PVC thermoplastic materials, Silicone is outstanding in environmental adaptability. It can be used at high and low temperatures and under a variety of environments for a long time, but still keep good performance. The outstanding performance is as follows:
Temperature Resistance
Silicone has good temperature resistance, the conventional temperature range of -40 ~ 230 degrees within the long-term use.
Environmental suitability
Silicone is not easy to be ultraviolet and ozone environment oxidation can be used in the natural environment.
Physical inactive
The compound siloxane is one of the most inactive compounds known. They are resistant to biological aging, no rejection reaction with the animal body, and have good anticoagulant properties, which can be used in a variety of environments.
Tensile strength
Silicone products have good surface tension, in which the main silane chain in the silicon molecule is more soft and flexible, so the tensile rebound strength is strong, long-term tensile rebound, no deformation.
Insulation
Silicone products have good electrical insulation properties, dielectric loss, resistance to voltage, resistance to arc, resistance to Corona, volume resistance coefficient, and surface resistance coefficient. Silicone is a good insulating material, therefore, it is one of the more stable electrical materials.
PVC
PVC is polyvinyl chloride. PVC belongs to plastic material. PVC compounds are the polymerization of vinyl chloride monomer, an azo compound, and other chemical aids at high temperatures. PVC materials can be made by polymer synthesis into different kinds of products, such asPVC sheet, PVC panel, PVC wall panel, PVC cable, PVC roll, PVC square tubing, PVC angle trim, etc. PVC material is a mainly white powdery amorphous material, density is 1.3-1.5, material vitrification temperature is within 90 degrees, the highest temperature resistance is 170 degrees. So in high temperature, PVC will be automatically decomposed into hydrogen chloride, beyond the temperature range will automatically catalyze decomposition.
There are two methods to identify PVC products
(1) identification by combustion method
Softening or melting temperature range 75 ~ 90 °C
Burning Flame(yellow upper, on the lower, is green), and has smoke. Self-extinguishing without fire.Has a pungent acid smell. This is the simplest and quick method.
Put the suspected PVC products into the above solvent, observe the dissolution of the products to determine whether it is PVC. When the solvent is heated, the dissolving effect will be more obvious.
For consumers, it is difficult to identify PVC products or silicone products. But here are some tips for your reference,
Touch
Silicone products have a soft and smooth feeling.
PVC touch is slightly hard and rough.
Color
The newly produced silica gel products are basically indistinguishable from the PVC products in color, but after long-term use, the PVC materials will appear sticky color and color yellowing, especially in the light and heat environment. Most silicone products rarely appear in such a situation.
Shore hardness
The shore hardness of silicone rubber can reach 30-90 degrees, while the conventional hardness of PVC is between 50-95. The hardness of silicone rubber material can be lower and softer, while the softness of PVC can not. Even though silicone in high shore hardness, it still has a good spring back strength, while PVC is relatively poor spring back strength.
Temperature
The processing temperature of silicone rubber is about 180 °C in the production process, and the normal temperature resistance is about-40 to 230 °C. PVC softening or melting temperature range is 75 ~ 90 degrees. In excess of temperature, both materials will have a certain amount of chemical reaction. Silica gel appears to be a white burning phenomenon. PVC will appear to soften, self-extinguishing without fire, and has a pungent acid smell.
Rebound strength
Rebound strength is the most important difference between these two materials. Silicone material has a good silicon molecular connecting strength, the rebound strength will be much better. While the PVC material has poor rebound.
Fluorosilicone is a good elastomer. The main chain is Si-O bond in its structure. After adding polar fluorine atoms (such as trifluoropropyl) into the side chain, the structure of fluorosilicone rubber is called CH2CH2CF3. Because of the strong electron-absorbing effect of fluorine atoms, the bond length of the C-F bond is shorter, it can form a good shielding effect to C-C bond, improve oil resistance and solvent-resistance of rubber, and make it a good elastomer with good resistance to non-polar medium at -68°C ~ 232°C. Therefore, fluorosilicone rubber is widely used in the field of the high-end locomotive and military aerospace seals.
As the price is expensive, and the electronic effect of fluorosilicone rubber, has strong adsorption to the surrounding dust, thus affecting the performance, so the production process of fluorosilicone rubber is very strict. Here is some suggestion of the production process.
Transportation and preservation. In the process of preservation and transportation, fluorosilicone rubber must be wrapped with insulating paper and plastic bags to prevent dust and impurities from contact with the rubber and adsorption.
Cutting fluorosilicone rubber. In the process of taking materials, cutting. First of all, using alcohol to scrub the surface of the knife or the tool scissors, after cleaning, can start the cutting. In the cutting process, try to avoid hand, skin, and rubber contact, but can not wear gloves, so as to avoid the pollution of glove fiber or skin oil on the fluorosilicone rubber.
Weighing fluorosilicone rubber. Before weighing, the tray needs to be cleaned with alcohol.
Fluorine silicone rubber mixing. Before mixing, must use alcohol scrub the mixer roller and baffle, to ensure no impurities contamination. When mixing, should pay attention to the roller temperature, when the roller temperature is 18 °C ~ 28 °C mixing process performance is better. If you need to add silica to adjust the hardness, you must first use hydroxyl fluorine silicone oil to pretreat the silica.
Vulcanization of fluorosilicone rubber. The mold used to produce fluoroelastomer products must be treated by surface treatment, chrome plating treatment, if necessary, use the external release agent.
Second vulcanization of fluorosilicone rubber. There is a lot of low molecular weight volatiles after the first vulcanization. Long-term use will affect the properties of the products, so the general products must be vulcanised in two stages. the second stage vulcanization is carried out in the electric heating blower, and the temperature is kept constant after the required temperature is reached by the way of step-by-step heating. For normal fluorosilicone rubber products, the temperature is 200℃ with 4 to 6 hours.
Re-mixing of fluorosilicone rubber. Long-term parking of fluorosilicone rubber easy structuralization, affect the performance, so for the use of long-term parking of rubber materials need to be re-mixing, placed in the mixer roll 25 times, mixing time of about 8 minutes, to ensure that materials mixed evenly.
Fluorosilicone rubber production environment. Because it has the characteristic of static electricity absorption ash, so the production environment needs to be purified and dust-free workshop, the production tool is the special equipment. Workers are required to wear clean clothes and hats for entry and exit operations.
Silicone is a thermosetting elastomer, with the advantages of safety and non-toxic. TPE meaning a Thermoplastic Elastomer material. It can be recycled and processed by injection molding. TPU is called Thermoplastic polyurethane elastomer. PVC is polyvinyl chloride, is the world’s largest production of common material, applications widely. Rubber there are many types of rubber, such as natural rubber, cis-1, butadiene-styrene rubber, propylene rubber, and of course silicone rubber.
Mobile phone cover, gloves, waterproof rings, toothbrush handles, various wheels, and sexy doll, etc. are made from soft material, but these materials used are different. What is the difference? how to choose the correct material? First of all, we need to consider the performance of the materials and what they used for. The main properties of soft material are hardness, elasticity, corrosion resistance, weather resistance, coefficient of friction, cracking, coloring, high (low) temperature resistance, cost, processing technology, etc. If used in daily necessities, baby products, etc. we need to pay attention to whether harmful to the human body, whether there is a bad smell, feel comfortable and other factors. Special circumstances also need to consider conductive performance (such as silica gel added conductive carbon can be made of silicone keypads), thermal conductivity, radiation resistance, light transmission performance.
TPE
TPE is Thermoplastic Elastomer, which is a Thermoplastic Elastomer material. Thermoplastic means it can be recycled and processed by injection molding. TPE products have excellent coloring, environmental protection, and non-toxic. Can be secondary injection molding, and PP, PE, PC, PS, ABS, and other matrix material coating adhesion, can also be molded alone.
TPE secondary injection molding handle
The heat resistance of TPE is not as good as that of rubber. With the increase of temperature, the physical properties of TPE decrease greatly, so its application is limited. At the same time, compression deformation, elastic recovery, durability is relatively poor than rubber. The price is also higher than rubber.
TPE material has a wide range of hardness, excellent transparency, gloss, and comfortable feel, widely used in adult products. With good UV resistance, weather resistance, high temperature resistance, long-term use in outdoor.
TPU
TPU (Thermoplastic polyurethanes) is called Thermoplastic polyurethane elastomer, the hardness range of TPE is from 60A to 70D of s shore hardness (now has soft TPU with a hardness of 45A around, but its price is very expensive), while the hardness range of TPE can be chosen from shore hardness scale 0 to 100 of shore hardness. Therefore, the TPE hardness ranges are medium-low hardness, while TPU hardness is medium-high hardness.
TPU is superior to TPE in elasticity and elastic recovery (flexure creep resistance). TPU main material is a polymer homogeneous structure, which belongs to the polymer resin. While TPE is a multi-component blend of multi-phase structure aggregation of alloy materials. TPE with high hardness is easy to deform, and TPU shows good elasticity in all hardness ranges, and the products are not easy to deform.
TPU spring wire
Some coated molded products, such as handles, wheels, maybe TPE or TPU. TPU material products, feel more roughly, friction resistance, while TPE material products feel more smooth and soft, friction is weak.
PVC
PVC is polyvinyl chloride, was the world’s largest production of common material, applications are wide. It should be noted that, on October 27, 2017, The Who’s International Agency for Research on Cancer published a preliminary list of carcinogens, polyvinyl chloride, in the list of 3 carcinogens.
PVC itself is a hard material, but with the addition of a plasticizer, can make the products soft, easy to bend, fold, with elasticity. Such as PVC sheet, PVC panel, etc.
PVC keychain
From the outside, the PVC product is coarser than the silica gel product, and the surface of the silicone product is smooth and colored. Judging by the hand feeling, the silica gel product quality is soft, toughness and elasticity are good, PVC soft glue is relatively hard. The soft and hardness of PVC and Silicone can be adjusted, but PVC no toughness.
There are common PVC materials and environmental PVC materials also known as ATBC-PVC. While silicone can pass the ROHS test, is environmentally friendly. Silicone products are generally made more transparent, burning smell slightly. After burning, PVC products will be black, smelly. Silicone products are more heat-resistant and cold-resistant, silicone products can be heated in the microwave oven, and PVC not.
Silicone
Silicone is a thermosetting elastomer, with the advantages of safety and non-toxic, insoluble in water and solvent, non-toxic tasteless, chemical property stability, no reaction with any material, high adsorption performance except strong alkali, hydrofluoric acid, good thermal stability, chemical property stability, the first widely used in medical products, food products, baby products, sports products, such as silicone bibs, menstrual cup, silicone caps, baby suction bowl, etc.
The processing of silicone products is complex, which needs a series of processes such as mixing, molding and vulcanized, etc. Silicone products are thermosetting rubber, after vulcanization when reheating silicone products will not melt. But silicone items can not be directly recycled reprocessing. Silicone products are generally more expensive than TPE products.
Silicone general shore hardness is 0A to 80A, and TPE general hardness in 0A-100A, the softest can reach 000 degrees or 0000 degrees, so TPE softer,
Silica gel has advantages over TPE in high-temperature resistance. Silica gel temperature in general between 200 degrees to 300 degrees. While TPE theory generally temperature between 130-150 degrees, and higher temperature, it will be aging cracking.
Silicone prices are higher than TPE prices except for the special TPE materials, such as halogen-free flame retardant, food-grade, and so on.
Rubber
There are many types of rubber, such as natural rubber, cis-1, butadiene-styrene rubber, propylene rubber, and of course silicone rubber; Silicone is one of the specific types of rubber, which is short for silicone rubber.
Silicone and rubber are two materials, we can use both under the same environment, but with the change of physical environment and requirements, the performance of the two materials will have a significant difference, but it takes time to manifest. For example, the most commonly used laboratory condensers, there are rubber and silicone, but silicone properties better, the anti-aging effect is significant. In structure, the main chain of rubber is mainly carbon, it is organic, while the main chain of silicone is mainly a Si-O bond, which is the main difference between them.
The coloring of silica gel is rich, can be made into a variety of different colors, rubber products are mostly black, occasionally can see other colors. For example, bicycle tires occasionally have other colors, and car tires are black. The reason is that the process of mixing rubber with carbon black and high-temperature condensation of carbon and hydrocarbon can make rubber very strong, wear-resistance, and anti-aging greatly improved. Rubber price is cheaper than silicone. Rubber molding is almost the same as the silicone molding process. Rubber is more widely used in industry, such as rubber coupling, rubber stoppers, rubber sleeve, rubber buffer, rubber fender, etc.
There are two most common Durometer scale, Shore A for flexible elastomers(range in hardness from very soft to medium, and to hard with almost no flexibility at all.) and Shore D for hard elastomers(hard rubbers, hard plastics). Before producing silicone items, It is very important to select the correct shore hardness of liquid silicone for different applications.
Shore A 0-degree application: it can be used for filling mould of super-soft silicone rubber mold, making of imitation prosthesis, such as mask, penis, sex articles, silicone rubber sheet, making of the soft gasket.
Shore A 5-degree application: it can be used for filling mold of super soft silica gel mould, making hand-made soap and candle silica gel mould, making imitation prosthesis products, such as mask, penis, sex articles, and silica gel sheet, making soft gasket products.
Shore A 10-degree application: can be used for soft silica gel mold filling mold production; hand soap, candle silica gel mold production; simulation of the production of prosthetic products, such as silica gel hands, feet, masks, penis, sex products, silica gel sheet, and soft gasket production.
Shore A 15-degree application: can be used for soft silicone mold filling mold production; hand soap, candle silicone mold production; simulation of the production of prosthetic products, such as silicone hand, foot, mask, penis, sex products, silicone skin, and soft gasket production.
Shore A 20-degree application: can be used for food-grade candy chocolate mold or single mold manufacturing; epoxy, polyester resin, polystyrene, vinyl plastic, paraffin wax, and other materials mold; Smallcement components, cultural stone, concrete, gypsum, and other products of mold manufacturing; 3d printing mold production, candle manual soap pouring mold production; mechanical properties of waterproof sealing use.
Shore A 25-degree application: can be used for food-grade candy chocolate mold or single mold manufacturing; epoxy, polyester resin, polystyrene, vinyl plastic, paraffin wax, and other materials mold; Small and medium-sizedcement components, cultural stone, concrete, gypsum, and other products of mold manufacturing; 3D printing model production, candle manual soap pouring mold production.
Shore A 30-degree application: can be used for metal crafts, alloy car and other precision mold manufacturing; epoxy, polyester resin, polystyrene, vinyl plastic, paraffin, and other materials mold; Large cement components, cultural stone, concrete, gypsum, and other products of mold manufacturing; high-precision hand plate model design, rapid prototyping design; used in vacuum bag multi-mold spraying class production.
Shore A 40-degree application: can be used for metal crafts, alloy car, and other precision mold manufacturing, as well as fixture protection; epoxy, polyester resin, polystyrene, vinyl plastic, paraffin, and other materials mold; Large cement components, cultural stone, concrete, gypsum, and other products of mold manufacturing; high-precision hand plate model design, rapid prototyping design; lost wax casting process of silicone mold production; product measurement reference production.
Shore A 50-60degree application: can be used for metal crafts, alloy car, and other precision mold manufacturing, as well as fixture protection; epoxy, polyester resin, polystyrene, vinyl plastic, paraffin, and other materials mold; Large cement components, cultural stone, concrete, gypsum, and other products mold manufacturing; high-precision hand plate model design, rapid prototyping design; product measurement reference production.
The hardness described above is only for the most extensive use. For special uses, it is important to know the part or product that you will be molding clearly.
LFGB (Lebensmittel-, Bedarfsgegenstände-und Futtermittelgesetzbuch, or “ “food, tobacco products cosmetics and other commodity management laws”), is the most important basic legal document in German food hygiene management. The specific LFGB standard: German Food, Articles of Daily Use and Feed Code of September 1, 2005 (LFGB), Section 30 & 31 with amendments and Regulation (EC) No 1935/2004 of the European Parliament and of the Council of 27 October 2004.
LFGB test requested, including extractable components, sensorial examination odour and taste test, Lead and Cadmium, Volatile organic matter(VOM) and Polycyclic aromatic hydrocarbons(PAHs) Content.
Test Requested
Conclusion
German Food, Articles of Daily Use and Feed Code of September 1,2005(LFGB), Section 30 & 31 with amendments and BfR recommendation -Extractable Components
PASS
German Food, Articles of Daily Use and Feed Code of September 1,2005(LFGB), Section 30 & 31 with amendments-Sensorial examination odour and taste test
PASS
German Food, Articles of Daily Use and Feed Code of September 1,2005(LFGB), Section 30 & 31 with amendments and BfR recommendation -Lead and Cadmium
PASS
German Food, Articles of Daily Use and Feed Code of September 1,2005(LFGB), Section 30 & 31 with amendments and BfR recommendation -Volatile organic matter(VOM)
PASS
Polycyclic aromatic hydrocarbons (PAHs) Content
PASS
German Food, Articles of Daily Use and Feed Code of September 1,2005(LFGB), Section 30 & 31 with amendments and BfR recommendation -Extractable Components
Test Method: With reference to 61. Mitteilung über die Untersuchung von Kunststoffen, Bundesgesundheitsbl 46 (2003) 362.
Simulant Used
Time
Temperature
Max.Permissible Limit
Result of 001
Comment
Distilled Water
4.0hr(s)
100℃
0.5%(w/w)
<0.1%(w/w)
PASS
3% Acetic Acid (W/V) Aqueous Solution
4.0hr(s)
100℃
0.5%(w/w)
<0.1%(w/w)
PASS
10% Ethanol (V/V) Aqueous Solution
4.0hr(s)
100℃
0.5%(w/w)
<0.1%(w/w)
PASS
Notes: %w/w = percentage of weight by weight
German Food, Articles of Daily Use and Feed Code of September 1, 2005 (LFGB), Section 30 & 31 with amendments-Sensorial examination odour and taste test
Test Method: With reference to DIN10955:2004, direct contact method. No.of panelist:6
German Food, Articles of Daily Use and Feed Code of September 1,2005(LFGB), Section 30 & 31 with amendments and BfR recommendation -Lead and Cadmium
Test Method: Microwave digestion (GZTC CHEM- TOP-004-01), analysis was performed by ICP-OES.
Test Items(s)
Limit
Unit
MDL
001
Cadmium (Cd)
★
mg/kg
2
ND
Comment
PASS
Lead (Pb)
★
mg/kg
2
ND
Comment
PASS
Notes: 1.mg/kg =milligram per kilogram of sample 2.MDL=Method Detection Limit 3.ND=Not Detected(less than MDL) 4.★=Absent
German Food, Articles of Daily Use and Feed Code of September 1,2005(LFGB), Section 30 & 31 with amendments and BfR recommendation -Volatile organic matter(VOM)
Test Method: With reference to 61. Mitteilung über die Untersuchung von Kunststoffen, Bundesgesundheitsbl 46 (2003) 362.
Test Items(s)
Limit
Unit
MDL
001
Test Temperature
–
℃
–
200
Test Time
–
hr(s)
–
4.0
Volatile organic matter (VOM)
0.5
%(w/w)
0.1
ND
Comment
PASS
Notes: 1. %w/w = percentage of weight by weight 2.MDL=Method Detection Limit 3.ND=Not Detected(less than MDL)
Polycyclic aromatic hydrocarbons (PAHs) Content
Test Method: With reference to AfPS GS 2014:01 PAK, analysis was performed by GC-MS.
Test Item(s): Sum of 18 PAHs. Sum of 7 PAHs Acenaphthylene, Acenaphthene, Fluorene, Phenanthrene, Pyrene, Anthracene, Fluoranthene. Naphthalene(NAP CAS NO. 91-20-3). Acenaphthylene(ANY, CAS NO.208-96-8). Acenaphthene(ANA, CAS NO.83-32-9). Fluorene(FLU, CAS NO.86-73-7). Phenanthrene(PHE, CAS NO.85-01-8). Anthracene(ANT, CAS NO.120-12-7). Fluoranthene(FLT, CAS NO.206-44-0). Pyrene(PYR, CAS NO.129-00-0). Benzo(a)anthracene(BaA, CAS NO.56-55-3). Chrysene(CHR, CAS NO. 218-01-9). Benzo(b)fluoranthene(BbF, CAS NO.205-99-2). Benzo(j)fluoranthene(BjF, CAS NO.205-82-3). Benzo(k)fluoranthene(BkF, CAS NO.207-08-9). Benzo(a)pyrene(BaP, CAS NO.50-32-8). Benzo(e)pyrene(BeP, CAS NO.192-97-2). Indeno( 1,2,3-c,d)pyrene(IPY, CAS NO.193-39-5). Dibenzo(a,h)anthracene(DBA, CAS NO.53-70-3). Benzo(g,h,i)perylene(BPE, CAS NO.191-24-2)
FDAtesting (Food & Drug Administration Standard) is the minimum safety standard for food-contact silicone products in the US & Australia. The specific standards is: United States Federal Code, Part 21, Food and Drugs (21 CFR).
FDA test requested
Test Requested
Conclusion
FDA 21 CFR 177.2600-Total extractive residues
PASS
FDA21 CFR 177.2600-Total extractive residues
Test Method: With reference to US FDA 21 CFR 177.2600.
Simulant Used
Time
Temperature
Max.Permissible Limit
Result of 002
Comment
Distilled Water
7.0hr(s)
Reflux temperature
20mg/sq.in
<0.5mg/sq.in
PASS
Succeeding Extraction
2.0hr(s)
Reflux temperature
1mg/sq.in
<0.5mg/sq.in
PASS
n-Hexane
7.0hr(s)
Reflux temperature
175mg/sq.in
9.2mg/sq.in
PASS
Succeeding Extraction
2.0hr(s)
Reflux temperature
4mg/sq.in
<0.5mg/sq.in
PASS
In summary…
LFGB silicone pass more strict testing and is therefore more expensive, while FDA silicone is more widely used, but silicone that has passed LFGB testing is definitely safer.
Different countries have different standards for food-contact silicone products. LFGB is standard mainly for Europe, while FDA (Food and Drug Administration) is standard in America(though different country has their own FDA standard, but US FDA is internationally applied.)
There are many different printing processes on silicone products. silicone silk screen printing, silicone printing, silicone color printing, silicone transfer printing, silicone film printing.
Silicone silkscreen printing
The silkscreen is the first printing method. Screen printing requires a logo screen set. Generally, the silk screen printing ink will be thicker and brighter, and the printed pattern has a strong dimensional sense. Silkscreen printing can also print thin lines and is also suitable for large-area printing. The disadvantage is that it is low efficiency as by hand printing and only can up to print 5colors. Silkscreen can only print one color at a time, bake it. Then fix another logo screen set to print the second color.
Silicone pad printing
It is printed by machine with a metal plate. The plate is flat, with the image chemically imprinted. The silicone pad is pressed onto the ink, picking up the image. And then the silicone pad is pressed onto the substrate, transferring the image on the silicone product.
The advantage of pad printing is that the printing speed is fast, and you can print several colors at the same time. Pad printing can be used on a variety of substrates, particularly oddly shaped objects that are difficult to screen print. The disadvantage is that the ink is slightly thinner than the silkscreen, not too bright.
Silicone color printing
color printing is also called digital printing, CMYK printing. The technique used to print full-color images. The silicone ink and the silica gel itself are chemically reacted with each other, so the based product should be white. Otherwise, the logo will be discolored. If the based products in different colors, it is better to print with white ink by silkscreen printing or pad printing first, then do the CMYK printing. However, because there is dust in the printing process, when there is color printing, there will be small dust particles on the surface.
Silicone heat transfer printing
Your custom logo is printed on transfer label or film first, and then ink is thermally transferred from the label to the silicone products using heat by press machine. It can print several color logo. But the logo screen is expensive.
Silicone water transfer printing
Firstly put the printed water-soluble film on the surface of the water. Immerse the silicone products into the water, the upward pressure of the water causes the ink to wrap and adhere to the item. Then removed the products from the water. It can be applied to all types of substrates with full colors printing.
Silicone film printing
Cover the film on the silicone while compressing the product, without secondary processing and printing. Washable, folding, scratch-resistant grade A, dry-wearing and wet-resistant grinding A grade, excellent color printing pattern, clear and vivid color printing pattern, environmental protection
Ukong can do the above all kind of silicone printing. We carefully evaluated all methods and help you choose the right way to print your silicone products.
TPE over-molding widely used in the thermoplastic elastomer industry. In recent years, with the rise of liquid silicone applications and the excellent properties of liquid silicone rubber materials, TPE over-molding products are gradually being replaced by liquid silicone rubber. The liquid silicone rubber has excellent comprehensive performance. LSR has high-temperature resistance than thermoplastics, soft-touch, high quality of materials meet with the medical-grade requirements. It is the best soft material for over-molding and injection molding and two-color injection molding.
Silicone over-molding is a process that is used to cover, bond, or encapsulate an existing part with silicone material.
The main advantages of liquid silicone over-molding
The liquid silicone rubber(LSR) material has excellent slip resistance and soft elastic touch, which can improve the touch feeling of the product and enhance the grip.
liquid silicone rubber has different hardness range Shore 10-90A according to the physical properties of the product, as well as suitable physical properties (such as abrasion resistance, adhesion, melt index, etc.). A variety of possible material application options are available for different products.
Liquid silicone rubber is an environmentally friendly raw material. It does not contain phthalates, halogens, and does not include 38 SVHC substances of REACH. It meets the environmental testing standards of ROHS, REACH, NP, EN71, and PAHS, and can fully meet the environmental protection requirements.
Silicone rubber over-mold injection molding process involves two steps wherein a completed plastic or metal entity is placed into the mold site of an LSR mold, after which the LSR is over-molded directly onto the part.
The injection molding temperature is different depending on the hard material. The commonly plastic substrate is PC or PA, and aluminum alloy can also be over-molded by liquid silicone rubber.
Common problems and solutions for liquid silicone rubber over-molding processing
1) Lack of silicone – the product is trapped air, or the silicone is not enough.
2) blunt, overflow edge – increase the clamping force; reduce the injection pressure.
3) Poor viscosity – choose the right adhesive. Check the plastic or metal substrate is clean.
4) out of shape during Injection molding – lowering the molding temperature; using a high-temperature resistant substrate.
Ukong is a liquid silicone product OEM/ODM manufacturer. We are committed to the development of new processes for liquid silicone (LSR) products and custom products. We have advanced molding techniques such as the high speed of injection molding, short vulcanization time, automatic, self-removing, and no burrs.
Our products including the liquid silicone rubber baby care, medical liquid silicone products, mobile phone 3C waterproof accessories, automotive electronic accessories, liquid silicone kitchen products, industrial sealed liquid silicone Products, etc. and has rich experience in the liquid silicone rubber over-molding parts. (liquid silicone rubber to plastic, liquid silicone rubber to metals, liquid silicone rubber to glass or ceramic, silicone two-color products)
