[Question] Plastic Densities

[kilgus]

^^Agreed, every company has something good that they offer and everyone playing has their own opinion on what they like to throw. Competition is good for the consumer in all aspects of the sport. The more quickly people realize that and stop bashing everything new that comes out then they are gonna see prices drop because now companies have to compete.

 

[Dan Ensor]

So is there a reason additives wouldn't be considered when determining the density of the plastic a disc is made out of?

 

[Halcón]

Here is something Zam mentioned:

BTW it is a significant amount of weight being moved. It's an optimization of the property every flying disc has -- weight near the outside. Fat rims get weight near the outside; GYRO puts a 5x-density material right at the edge. Double-digit grams added. It's a very simple optimization. It changes the flight but it's not so drastic as to make it totally foreign, which is what I think some people expect.

 

[kilgus]

So is there a reason additives wouldn't be considered when determining the density of the plastic a disc is made out of?

Not sure if I'm answering your question appropriately but additives add cost sometimes it's nearly the cost of the resin itself. In my experience adding $1 to the cost of a base plastic because of resin is not beneficial in terms of a business stand point. Many base plastics cost as much or sometimes more than your premium plastic....

Color additives typically don't add weight btw

 

[Dan Ensor]

I'm asking if there would be a reason that you would consider plastics different densities, even if they have the same weight and volume, because of some quality of additives vs. the plastic being added to (perhaps the additive sluffs off the outside where wind contacts the disc?)?

 

[kilgus]

^^to answer your question the density is directly related to weight. Lower the density, lower the weight no matter what the size of the mold is volume wise.

Additives don't typically rub off unless it's a weighting agent like zinc,barium sulfate etc. Basically a manufacturer will pick a plastic that has a density that doesn't have to have a weight additive added and a material that is easy to source with a good price.

 

[46YearOldSlinger]

This isn't a zero sum game: MVP discs can have something special about them, and so can Innova discs or Lat 64 discs, et cetera.

Alcuin,
I'm not sure if you're aware of the rules but an internet message board is no place for such a logical statement - LOL. Couldn't agree more. Every company has their sweet spot. For me MVP provides discs I can shape, control, predict, and range better than most. Lat64/Trilogy discs seem to give me more distance/glide than any other manufacturer. Innova - well when you make that many molds some of them are bound to come out sweet - Tern and Nova would be hard for me to replace. I love options. How can you not love options!

 

[JedV]

Cool insight Kilgus. Thank you for your insider information in this thread :clap:

 

[DISCenchanted]

Here is something Zam mentioned:

Based on the information that kilgus provided, "5x density" and "double digit grams added" are gross overstatements...

 

[nolangherity]

people who think GYRO™ is a scam have never gotten an mvp disc up to speed.

 

[Halcón]

Based on the information that kilgus provided, "5x density" and "double digit grams added" are gross overstatements...

The information that kilgus has provided tells us nothing of the difference in the specific gravity of the core vs the overmold in MVP discs. The densities of the polymers he mentioned are not including any added weighting agents that MVP uses.

 

[iacas]

This isn't exactly the toughest thing to test.

Cut up an MVP disc. Measure the volume of the overmold, the volume of the core material you have, and weigh each. A college student could do this easily (they have access to better scales than, say, a postage scale), or someone with a job that uses reasonably precise scales.

I've always suggested that the overmold is mostly marketing and makes very little difference. And I have a LOT of MVP discs (I like their looks and consistency, and they have generally filled slots pretty well).

 

[Aim For The Chains]

Good luck separating the OM from the core...

Disc golfers are funny-they worry about a few gram weight differences like its going to make a disc fly completely different but added weight to a overmold is just a joke. Lulz.

 

[kilgus]

The information that kilgus has provided tells us nothing of the difference in the specific gravity of the core vs the overmold in MVP discs. The densities of the polymers he mentioned are not including any added weighting agents that MVP uses.

You are right but your wording is slightly off. The specific gravity of each resin won't change. The TPE core they use for neutron at it's lowest is a .9 specific gravity, the outer TPR ring they use is a 1.25 specific gravity at most. If MVP used the same amount TPE and TPR they would get a disc that weighed roughly 160-165g if both the core and mold were the same volume, however this is is not the case and the rim has roughly 2/3 the weight and the core 1/3 giving you a closer to max weight disc. Basically at this point adding any weighting additive is not possible because you would have an overweight disc.

Secondly the proton plastic which is TPU has a specific gravity of 1.14-1.2+ making the difference between core and over mold densitys nearly indescernable other then volume of each added which again will be roughly 2/3 vs 1/3. So I would guess you would get a more gyro effect (going only by density) with the neutron plastic vs. proton. I haven't thrown enough to know the difference between the two plastics but I also know that talking to Dave Dunipace from innova that he thinks the "gyro" effect is slight just based off of plastic densities.

Again I enjoy the MVP guys and think they bring a great alternative to the game and are glad they are part of the sport!

Hopefully I have helped shed some light on molding and resins by an insider.

 

[DISCenchanted]

Good luck separating the OM from the core...

Disc golfers are funny-they worry about a few gram weight differences like its going to make a disc fly completely different but added weight to a overmold is just a joke. Lulz.

Good point. Anything under 4-5g is not going to make a noticeable difference. And disc markings can be off by as much as 4-5g...

 

[DISCenchanted]

You are right but your wording is slightly off. The specific gravity of each resin won't change. The TPE core they use for neutron at it's lowest is a .9 specific gravity, the outer TPR ring they use is a 1.25 specific gravity at most. If MVP used the same amount TPE and TPR they would get a disc that weighed roughly 160-165g if both the core and mold were the same volume, however this is is not the case and the rim has roughly 2/3 the weight and the core 1/3 giving you a closer to max weight disc. Basically at this point adding any weighting additive is not possible because you would have an overweight disc.

Secondly the proton plastic which is TPU has a specific gravity of 1.14-1.2+ making the difference between core and over mold densitys nearly indescernable other then volume of each added which again will be roughly 2/3 vs 1/3. So I would guess you would get a more gyro effect (going only by density) with the neutron plastic vs. proton. I haven't thrown enough to know the difference between the two plastics but I also know that talking to Dave Dunipace from innova that he thinks the "gyro" effect is slight just based off of plastic densities.

Again I enjoy the MVP guys and think they bring a great alternative to the game and are glad they are part of the sport!

Hopefully I have helped shed some light on molding and resins by an insider.

You absolutely have. This kind of concrete(plastic?) information is a rarity in the DG forum/Facebook page croud.

 

[kilgus]

You absolutely have. This kind of concrete(plastic?) information is a rarity in the DG forum/Facebook page croud.

I'm glad I can help. Hearing everyone's thoughts opens up a healthy discussion

 

[ZAMson]

Based on the information that kilgus provided, "5x density" and "double digit grams added" are gross overstatements...

The 5x density is a figure I got from the owners (of MVP). As for the double digits added, I weighed a core without its overmold, fresh out of the machine. The weight of that disc missing nothing but its nose cone, about to become max weight, makes me believe that their 5x density claim is dead on.

Maple Valley Plastics overmolded plastics for decades before making discs; it's second nature there to overmold. Any company would try to make their discs the best they can, and these guys have the rare capability to place a really dense variant at the nose.

I dug up a quote from the Q&A:

In our early days, we took an ultralight Wizard (~110g) and taped washers as weights to bring the overall disc weight to 175g. We did trials with mass taped in the very center, some with mass taped towards the outside, and weight distributions in between. The affect on flight from the weight distribution is very evident. The further you distribute mass away from the axis of rotation, the tighter the lateral movement of the disc. Although it was a primitive test, the principal still holds. We encourage everyone to try this experiment themselves.

 

[kilgus]

The 5x density is a figure I got from the owners (of MVP). As for the double digits added, I weighed a core without its overmold, fresh out of the machine.The weight of that disc missing nothing but its nose cone, about to become max weight, makes me believe that their 5x density claim is dead on.

Maple Valley Plastics overmolded plastics for decades before making discs; it's second nature there to overmold. Any company would try to make their discs the best they can, and these guys have the rare capability to place a really dense variant at the nose.

I dug up a quote from the Q&A:

In our early days, we took an ultralight Wizard (~110g) and taped washers as weights to bring the overall disc weight to 175g. We did trials with mass taped in the very center, some with mass taped towards the outside, and weight distributions in between. The affect on flight from the weight distribution is very evident. The further you distribute mass away from the axis of rotation, the tighter the lateral movement of the disc. Although it was a primitive test, the principal still holds. We encourage everyone to try this experiment themselves.

Not sure if I'm reading this correct but a near max weight core would mean the outer rim would have to have little to no weight in it which is directly the inverse of gyro. I'm assuming you meant the outer rim was near max weight. I agree a thin core (aka thin flight plate) with a .9 specific gravity could lead to the outer rim being much heavier but in terms of being significant I can't agree or refute that. Either way MVP's father has been in the business for an extended period of time so I'm sure they have the formula matched to get the best gains possible!

I will say I have no direct information on what MVP does other than what Dave D has said and what I know about resins and the traditional" injection molded discs.

 

[ZAMson]

Not sure if I'm reading this correct

You're not. It was an extremely light core, and it had not yet been overmolded to become a max-weight disc.

I will say I have no direct information on what MVP does other than what Dave D has said

And Dave D has no direct information on what MVP does either.