TPE and me - the evolving story
Posted: Fri Jul 29, 2016 1:03 am
Hi,
Thermoplastic elastomers, aka TPE, are evolving into the material of choice because of feel and cost. Never owning a doll I can’t say which is best, silicone or TPE, as my research has shown each has pro and cons. High end dolls manufactures still hold fast to the durability of silicon, which has been proven over the years to be reliable.
There are a number of factors that distinguish TPE from silicon. Silicon is a “one time” process, meaning production mistakes are tossed into the dumpster where TPE can be introduced back in to processing, with limitations. Each time TPE is reused it degrades, which speaks volumes about the manufacturing process. {1} Each manufacturing plant has their own recipe for mixing TPE, which means there is a difference in the coherent properties and recycling useage.
One the most obvious differences is applied color adhesion post molding, TPE surface applied color is know to fade where silicon has a superior color retention. TPE is colored at the time of molding with conventual plastic pigments. {2} polypropylene (PP), ethylene vinyl acetate (EVA), or polyethylene (PE). {3} Silicon pigments in liquid state can be applied to silicon after molding with brush or spray retaining good color saturation.
Here is an email conversation I had with one of manufactures of TPE pellets that supply the Chinese sex doll market:
“Dear Sir,
Thank you for your patience.
a. Can TPE used for sex toys be painted or died with silicone pigments after it has been molded?
b. Any products that can be applied after molding that will change the color of TPE and last long?
Engineer advised as below:
Sex toys, assuming that they are all soft thermoplastic products, may be painted or dyed post-mold with pigments UNLESS the product is made out of TPRs (SEBS-based) as TPR products have much better adhesion with pigments on surface than SBS-based TPEs. Colors on products should be stable and last long. But Engineer cannot confirm whether it works well with silicone pigments. Suggest you may do a little test with it first. “
After reading this I worked on another way to apply color to molded TPE. Knowing the material can be recycled, knowing it can be melted an reintroduced to the production stream, I looked at the melting point of TPE. {4} My working theory is applying liquid plastic pigment to molded TPE and using controlled heating bring the TPE and plastic pigment close to flow temperature. The final result is a controlled pigmented area on TPE.
Please feel free to comment.
Reference:
{1} https://en.wikipedia.org/wiki/Thermoplastic_elastomer
{2} http://www.matweb.com/search/datasheett ... 1ca6802401
{3} https://www.youtube.com/watch?v=LwmkRpCEvlc
{4} http://www.gainshinetpe.com/products/tpe-for-sex-toys
Thermoplastic elastomers, aka TPE, are evolving into the material of choice because of feel and cost. Never owning a doll I can’t say which is best, silicone or TPE, as my research has shown each has pro and cons. High end dolls manufactures still hold fast to the durability of silicon, which has been proven over the years to be reliable.
There are a number of factors that distinguish TPE from silicon. Silicon is a “one time” process, meaning production mistakes are tossed into the dumpster where TPE can be introduced back in to processing, with limitations. Each time TPE is reused it degrades, which speaks volumes about the manufacturing process. {1} Each manufacturing plant has their own recipe for mixing TPE, which means there is a difference in the coherent properties and recycling useage.
One the most obvious differences is applied color adhesion post molding, TPE surface applied color is know to fade where silicon has a superior color retention. TPE is colored at the time of molding with conventual plastic pigments. {2} polypropylene (PP), ethylene vinyl acetate (EVA), or polyethylene (PE). {3} Silicon pigments in liquid state can be applied to silicon after molding with brush or spray retaining good color saturation.
Here is an email conversation I had with one of manufactures of TPE pellets that supply the Chinese sex doll market:
“Dear Sir,
Thank you for your patience.
a. Can TPE used for sex toys be painted or died with silicone pigments after it has been molded?
b. Any products that can be applied after molding that will change the color of TPE and last long?
Engineer advised as below:
Sex toys, assuming that they are all soft thermoplastic products, may be painted or dyed post-mold with pigments UNLESS the product is made out of TPRs (SEBS-based) as TPR products have much better adhesion with pigments on surface than SBS-based TPEs. Colors on products should be stable and last long. But Engineer cannot confirm whether it works well with silicone pigments. Suggest you may do a little test with it first. “
After reading this I worked on another way to apply color to molded TPE. Knowing the material can be recycled, knowing it can be melted an reintroduced to the production stream, I looked at the melting point of TPE. {4} My working theory is applying liquid plastic pigment to molded TPE and using controlled heating bring the TPE and plastic pigment close to flow temperature. The final result is a controlled pigmented area on TPE.
Please feel free to comment.
Reference:
{1} https://en.wikipedia.org/wiki/Thermoplastic_elastomer
{2} http://www.matweb.com/search/datasheett ... 1ca6802401
{3} https://www.youtube.com/watch?v=LwmkRpCEvlc
{4} http://www.gainshinetpe.com/products/tpe-for-sex-toys