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Bears Two Color Injector Problem

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I can't get the technigue down for doing laminates with my set up. Every time I fill one injector and let in set in the cup by the time I get the other filled and go to inject, the tips are clogged. What do I need to do get plastic hotter or what?

By the way I have Bears two color injector kit, with the offset nozzles.

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That is the only setup that I have to heat in order to get it to work well on lams. I put them on a hot plate covered with a griddle to get them warmed up to around body temp.

Then I suck up plastic and evacuate a time or two to get them really warm. After that I am good to go till my molds are full.

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You will find that some people say not to and some say it's okay. Yes, he has his on a griddle and you will find that several do. It's your choice, just be careful and take safety precautions.

How is Frank keeping his plastic hot, I thought you were not suppose to put pyrex on hot plates?

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How is Frank keeping his plastic hot, I thought you were not suppose to put pyrex on hot plates?

The cups look like the (beakers ?) that are used in a chemical lab or you might have used in your science class. Not pyrex glass. They are heated using a alcohol burner most of the time so I think the heat off the bottom with a hot plate would be the same. Good thinking frank.

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Yep, that is correct Frank uses beakers. Some people use pyrex on a griddle also. I have not tried it myself but read about people using pyrex on the griddle. Just be cautious if you do.

The cups look like the (beakers ?) that are used in a chemical lab or you might have used in your science class. Not pyrex glass. They are heated using a alcohol burner most of the time so I think the heat off the bottom with a hot plate would be the same. Good thinking frank.

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Yep, that is correct Frank uses beakers. Some people use pyrex on a griddle also. I have not tried it myself but read about people using pyrex on the griddle. Just be cautious if you do.

he used two pyrex/anchor cups for the heated colours and 2 beakers for the sprues

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SHK is right I use two pyrex type cups as a main cup. The thin beakers help keep the sprues melting as they just resting there. I am using a griddle and NOT a hot plate. This is like putting a pan on a hot plate and then the pyrex. The pyrex is not in direct contact with the heating element. People seam to think a hot plate and griddle are the same but my hot plate will get red hot and way above a safe temp for plastic, the griddle on the other hand will barely keep the plastic hot enough to use a few time before you have to reheat( only 30sec or so). The griddle also has high sides in case of a spill/break. The beakers do a good job but are a little thin even though I have not broken one. I am not saying it is ok to put pyrex on a heat source I am just showing how I do it. I put my pyrex in my oven in the house not sure why it is not ok to do it in the garage on a griddle. Think about it. Frank

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Thermal shock is usually what makes tempered glass like Pyrex fail. That means abrupt cold to hot, or vice versa. If you have heated your plastic/pyrex in a microwave, and then sit it on a hot plate, it's not a problem because the pyrex is already heated. Just don't sit hot pyrex on a cold surface, or it will shatter.

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Thermal shock is usually what makes tempered glass like Pyrex fail. That means abrupt cold to hot, or vice versa. If you have heated your plastic/pyrex in a microwave, and then sit it on a hot plate, it's not a problem because the pyrex is already heated. Just don't sit hot pyrex on a cold surface, or it will shatter.

I agree Mark. When you place the cold Pyrex on a hot surface, the heated part expands rapidly and the surrounding glass does not. This stresses the glass with shear forces and little cracks are formed. It won't necessarily break the first time or even the tenth, but each time the stress cracks increase until it finally gives in and explodes.

You can examine the base of your Pyrex closely. If you see any cracks or crazing, then it is time to discard or find a safer use for it.

Dave

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I can't get the technigue down for doing laminates with my set up. Every time I fill one injector and let in set in the cup by the time I get the other filled and go to inject, the tips are clogged. What do I need to do get plastic hotter or what?

By the way I have Bears two color injector kit, with the offset nozzles.

Evacuate your injector at least two times, also how much plastic are you heating up? when I first tried it I was using 2ounces of each color and this was not working, at least do 4 ounces, once I did these two things I was producing two color baits

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Thanks for all the replys. I just got one of Bear's blending block and I am making beautiful laminates now. I think I will get a griddle and try, instead of having to zap my plastic each time. Maybe that will speed up my production.

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Yep, that is correct Frank uses beakers. Some people use pyrex on a griddle also. I have not tried it myself but read about people using pyrex on the griddle. Just be cautious if you do.

Pyrex measuring cups, Anchor measuring cups, lab type beakers are all borosilicate glass and have the same properties.

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Thanks for all the replys. I just got one of Bear's blending block and I am making beautiful laminates now. I think I will get a griddle and try, instead of having to zap my plastic each time. Maybe that will speed up my production.

How do you hold the two injectors and load them on the adapter. I am curious and have not heard anyone talk about that.With mine they both fill at the same time and I still use two hands to set it on the adapter. Boy you got the adapter fast. Frank

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How do you hold the two injectors and load them on the adapter. I am curious and have not heard anyone talk about that.With mine they both fill at the same time and I still use two hands to set it on the adapter. Boy you got the adapter fast. Frank

Frank I've got the small injectors and I fill one and lay it on the bench, then I fill the other and with it in one hand, I pick the other up and drag across bench to get clog off.. Then with one in each hand I stick them in the blending block snd then I push plungers down with one hand while holding the block with the other.

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I can't get the technigue down for doing laminates with my set up. Every time I fill one injector and let in set in the cup by the time I get the other filled and go to inject, the tips are clogged. What do I need to do get plastic hotter or what?

By the way I have Bears two color injector kit, with the offset nozzles.

Not to over simplify, but order a Blending Block. Makes laminates SO MUCH EASIER.

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Pyrex measuring cups, Anchor measuring cups, lab type beakers are all borosilicate glass and have the same properties.

I'm sorry, but with all due respect, Smallie, you are perpetuating a widespread myth.

Past posts of instances of "exploding" Pyrex cups prompted me to do some internet research into Pyrex products. For what it's worth this is what I've found -

Look HERE. This is the Pyrex North American website.

Pyrex glassware products (bakeware, measuring cups, etc) manufactured in the U.S. (Pennsylvania) are made of soda lime glass - not borosilicate glass.

Pyrex glassware products manufactured in Europe are borosilicate glass.

My understanding is that the manufacturing process (as well as the raw materials) that go into the making of soda lime glassware is cheaper and this was the fundamental justification for the change in the U.S. - in the 1940s. Why it has not changed in Europe, I don't know. It may have something to do with governmental regulation.

Look HERE at the Pyrex European website. In this FAQ section, the question is asked, "What is Pyrex made of?" The answer (for European manufactured Pyrex products) is, "Pyrex is made out of borosilicate glass: a special blend of sand, boron and other 'ingredients'. These components are heated to very high temperatures and melted in order to form glass."

From what I could find, all Pyrex laboratory glassware is made of borosilicate glass regardless of geography.

Lastly - Anchor's FAQ page HERE states a couple times, "Today, all U.S. manufactured glass bakeware, regardless of manufacturer, is made from tempered soda-lime-silicate glass."

Hope this isn't considered a thread highjacking. I just wanted to share what I learned through some simple research.

Rick

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