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injection molded polycarb (lexan) lips
8 replies to this topic
Posted 16 December 2004 - 11:15 AM
Finally got an answer. The initial cost is a killer. But the piece count after that is really reasonable. I have a contact that will create the mold for $750.00 to $1000.00 and then the lips are .10 cents each after that with a minimum run of 1000 pieces. If you were doing some serious production, this would be the way to go.
Posted 16 December 2004 - 04:28 PM
For what size press?
How many cav.?
Because it seems really low on the mold price.
Posted 16 December 2004 - 04:46 PM
Not 100 percent sure but I believe he said 4 cavity aluminum....because it could handle up to 10000 pieces before wearing out. Aluminum vs Steel. Alot more money for steel. I cant imagine making 10000 baits by hand. Not me anyway. This guy specializes in molds for fishing tackle. Email me and I will get you his info.
Posted 16 December 2004 - 08:08 PM
Watch what you get. Injection molds are rated by how many pounds of pressure that they will handle by the injection press. For the lips you are looking at 10s of thousands pounds of pressure. The bands around the mold are rated also. For a 2 cavity mold made of steel you are looking around $5500.00 The last quote I got was $5800.00. If you really get into the business heavy enough you will make between 3000 and 5000 baits a year. So you would need the mold to last. I have never heard of an aluminum mold. I would check with the company doing the injections. If the mold does not meet their specs then they wont shoot it.
Posted 17 December 2004 - 10:15 AM
I just finished a course on metallurgy and our instructor worked for a plastic injection company, we got to tour his plant they made parts for Toyota,Ford and Gm, alot of their molds were alum. Strength of the aluminum depends on what alloys are added, anyway we were told that most alum. molds are used for short term runs,prototypes etc..because of cost and ease of machining. We never heard how many parts they were good for tho.
Posted 17 December 2004 - 10:15 AM
I had no clue. Keep the info coming guys.. It is always good to learn. I would definately want them done right. If you dont know what to ask...???? Although, I will say this....this guy specializes in fishing tackle and said he was presently working on some bills. Made it sound like he does this all the time.
Posted 17 December 2004 - 03:30 PM
Just seams that that expected shot count is way low.
Most injection molders would laugh at a run that small.
Maybe it is just for a proto type run.
Poly carb. is not fun to run, it must be pre-heated and dryed before put in the the hopper.
Cleaning it from the barrel can require a screw change just to speed things along.
And the stuff is hell on the grinding mahines.
Was this one to have any insert in it?
Line tie/weight, more trouble with run them that way.
Posted 17 December 2004 - 06:13 PM
That was a good point. The actual mold of the lip is inserted into the injection block. The block is banded and then polycarbonate is injected thru the block and into the mold. Most polycarbonate comes in pellet form. It is put in the injection machine, melted down, and then shot into the mold at a tremendous pressure. That is why you need to know how strong the block and mold need to be. You need the information from the folks doing the injection. Otherwise you could buy a block and mold that no one will shoot.
Posted 17 December 2004 - 11:05 PM
I have checked this guys site.......
And he looks as if he really knows what he is doing.
Ton size on the machines is the clamping pressure.
It also limits the size of the mold that can be hung in it.
Have seen a womans fingures crushed to paper thin by one.
Another guy burned up, when a barrel exploded.
4 years in a high production plastics plant.
Sounds like this one would be a little guy.