Plastic strikes again!

Discussion in 'Digital Photography' started by RichA, Aug 14, 2011.

  1. RichA

    PeterN Guest

    On 8/16/2011 8:57 AM, RichA wrote:
    > On Aug 15, 7:59 pm, PeterN<> wrote:
    >> to clarify my prior response.
    >>
    >> What adjustments are needed for the coefficient of expansion for each of
    >> the materials, when removing them from the mold?
    >>
    >> --
    >> Peter

    >
    > You are assuming the mold is actually any good and the problem isn't
    > happening there, with the equipment. 20 years ago, an optics firm in
    > California was turning out terrible products because old mold masters
    > were worn. Didn't fix the problem until they replaced them.
    > Half the Chinese production used to be (still?) done in their
    > backyards over bonfires. That's how they render down old electronics
    > to scavenge metals to this day.


    I am assuming that you would answer my question.

    --
    Peter
     
    PeterN, Aug 16, 2011
    #21
    1. Advertising

  2. RichA

    PeterN Guest

    On 8/15/2011 10:57 PM, Robert Coe wrote:
    > On Sun, 14 Aug 2011 19:38:07 -0400, PeterN<>
    > wrote:
    > : On 8/14/2011 5:22 PM, Robert Coe wrote:
    > :> On Sun, 14 Aug 2011 10:41:35 -0700 (PDT), RichA<> wrote:
    > :> : Damn that contraction plastic experiences after hot molding!!
    > :> :
    > :> : http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658
    > :>
    > :> IOW, you can make a bad product out of a good material if you cut corners
    > :> or don't handle the material properly. Actually, I think we knew that,
    > :> but thanks anyway for reminding us. It's a dog-eat-bone world out there,
    > :> and one can hardly be too careful.
    > :>
    > :
    > : I wonder how much effort Rich has put in to compare the coefficient of
    > : expansion used, with the coefficient of expansion of likely metallic.
    > : And if so, how they are treated in the finished product.
    >
    > I believe that some kinds of plastic are more likely to shrink than to expand
    > under excess heat, as volatile substances are driven out. I wonder if the
    > problem is that the camera was left for hours in a broiling hot car.
    >


    that makes sense. I thought the coefficient of expansion applies to
    variations in temperature. You are introducing a new component. I am not
    an engineer. But why wouldn't the volatile substances driven out during
    a heat molding process. Unless, perhaps substances in the plastic change
    characteristics over time and become volatile.


    --
    Peter
     
    PeterN, Aug 16, 2011
    #22
    1. Advertising

  3. RichA

    PeterN Guest

    On 8/16/2011 8:59 AM, RichA wrote:
    > On Aug 15, 7:20 pm, PeterN<> wrote:
    >> On 8/14/2011 11:50 PM, Rich wrote:
    >>
    >>> PeterN<> wrote in news:4e481427$0$12461
    >>> $-secrets.com:

    >>
    >>>> On 8/14/2011 1:41 PM, RichA wrote:
    >>>>> Damn that contraction plastic experiences after hot molding!!

    >>
    >>>>> http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658

    >>
    >>>> Is shoddy manufacturing, or the material used?

    >>
    >>> Could be that, partly. Panasonic shifted solid production from Japan to
    >>> China.

    >>
    >> It's in their blood, right?

    >
    > Only heavy metals and effluents from burned plastic. China is a
    > polluted cess-pit.
    >
    >


    No other people have ever done that, right?
    Only the Chinese?

    Must be the folk that set the Cuyahoga on fire ate too much Chinese food.


    --
    Peter
     
    PeterN, Aug 16, 2011
    #23
  4. RichA

    Martin Brown Guest

    On 16/08/2011 16:08, PeterN wrote:
    > On 8/15/2011 10:57 PM, Robert Coe wrote:
    >> On Sun, 14 Aug 2011 19:38:07 -0400, PeterN<>
    >> wrote:
    >> : On 8/14/2011 5:22 PM, Robert Coe wrote:
    >> :> On Sun, 14 Aug 2011 10:41:35 -0700 (PDT),
    >> RichA<> wrote:
    >> :> : Damn that contraction plastic experiences after hot molding!!
    >> :> :
    >> :> :
    >> http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658
    >> :>
    >> :> IOW, you can make a bad product out of a good material if you cut
    >> corners
    >> :> or don't handle the material properly. Actually, I think we knew that,
    >> :> but thanks anyway for reminding us. It's a dog-eat-bone world out
    >> there,
    >> :> and one can hardly be too careful.
    >> :>
    >> :
    >> : I wonder how much effort Rich has put in to compare the coefficient of
    >> : expansion used, with the coefficient of expansion of likely metallic.
    >> : And if so, how they are treated in the finished product.
    >>
    >> I believe that some kinds of plastic are more likely to shrink than to
    >> expand
    >> under excess heat, as volatile substances are driven out. I wonder if the
    >> problem is that the camera was left for hours in a broiling hot car.
    >>

    >
    > that makes sense. I thought the coefficient of expansion applies to
    > variations in temperature. You are introducing a new component. I am not
    > an engineer. But why wouldn't the volatile substances driven out during
    > a heat molding process. Unless, perhaps substances in the plastic change
    > characteristics over time and become volatile.


    Depends critically on the plastic. Some do contain a trace amount of
    unreacted monomer that gradually escapes as the material ages. New car
    smell is a mix of various plasticisers and traces of monomer.

    Most precision engineering plastics are heavily filled composite
    materials with properties that are *much* better than raw plastic.

    What typically happens in a hot car is that very gradually the
    plasticisers come out of any flexible bits of plastic and they gradually
    become more brittle. A fate which is accelerated by UV exposure. The
    thin layer of gunge that condenses on the inside of the windscreen is a
    mixture of those plasticisers and human skin oils.

    Something like a bubble pack for hifi leads or batteries that is blow
    moulded from thin thermoplastic sheet will revert to a somewhat mangled
    version its original unstressed shape if you pour boiling water on it.
    Crosslinked thermoset polymer like epoxy will hold its shape whatever.

    Regards,
    Martin Brown
     
    Martin Brown, Aug 16, 2011
    #24
  5. RichA

    PeterN Guest

    On 8/16/2011 11:23 AM, Martin Brown wrote:
    > On 16/08/2011 16:08, PeterN wrote:
    >> On 8/15/2011 10:57 PM, Robert Coe wrote:
    >>> On Sun, 14 Aug 2011 19:38:07 -0400, PeterN<>
    >>> wrote:
    >>> : On 8/14/2011 5:22 PM, Robert Coe wrote:
    >>> :> On Sun, 14 Aug 2011 10:41:35 -0700 (PDT),
    >>> RichA<> wrote:
    >>> :> : Damn that contraction plastic experiences after hot molding!!
    >>> :> :
    >>> :> :
    >>> http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658
    >>> :>
    >>> :> IOW, you can make a bad product out of a good material if you cut
    >>> corners
    >>> :> or don't handle the material properly. Actually, I think we knew
    >>> that,
    >>> :> but thanks anyway for reminding us. It's a dog-eat-bone world out
    >>> there,
    >>> :> and one can hardly be too careful.
    >>> :>
    >>> :
    >>> : I wonder how much effort Rich has put in to compare the coefficient of
    >>> : expansion used, with the coefficient of expansion of likely metallic.
    >>> : And if so, how they are treated in the finished product.
    >>>
    >>> I believe that some kinds of plastic are more likely to shrink than to
    >>> expand
    >>> under excess heat, as volatile substances are driven out. I wonder if
    >>> the
    >>> problem is that the camera was left for hours in a broiling hot car.
    >>>

    >>
    >> that makes sense. I thought the coefficient of expansion applies to
    >> variations in temperature. You are introducing a new component. I am not
    >> an engineer. But why wouldn't the volatile substances driven out during
    >> a heat molding process. Unless, perhaps substances in the plastic change
    >> characteristics over time and become volatile.

    >
    > Depends critically on the plastic. Some do contain a trace amount of
    > unreacted monomer that gradually escapes as the material ages. New car
    > smell is a mix of various plasticisers and traces of monomer.
    >
    > Most precision engineering plastics are heavily filled composite
    > materials with properties that are *much* better than raw plastic.
    >
    > What typically happens in a hot car is that very gradually the
    > plasticisers come out of any flexible bits of plastic and they gradually
    > become more brittle. A fate which is accelerated by UV exposure. The
    > thin layer of gunge that condenses on the inside of the windscreen is a
    > mixture of those plasticisers and human skin oils.
    >
    > Something like a bubble pack for hifi leads or batteries that is blow
    > moulded from thin thermoplastic sheet will revert to a somewhat mangled
    > version its original unstressed shape if you pour boiling water on it.
    > Crosslinked thermoset polymer like epoxy will hold its shape whatever.
    >
    > Regards,
    > Martin Brown


    Thanks for that explanation.


    --
    Peter
     
    PeterN, Aug 16, 2011
    #25
  6. RichA

    John A. Guest

    On Tue, 16 Aug 2011 05:52:58 -0700 (PDT), RichA <>
    wrote:

    >On Aug 15, 7:20 pm, PeterN <> wrote:
    >> On 8/14/2011 11:50 PM, Rich wrote:
    >>
    >> > PeterN<>  wrote in news:4e481427$0$12461
    >> > $-secrets.com:

    >>
    >> >> On 8/14/2011 1:41 PM, RichA wrote:
    >> >>> Damn that contraction plastic experiences after hot molding!!

    >>
    >> >>>http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658

    >>
    >> >> Is shoddy manufacturing, or the material used?

    >>
    >> > Could be that, partly.  Panasonic shifted solid production from Japan to
    >> > China.

    >>
    >> It's in their blood, right?
    >>
    >> --
    >> Peter

    >
    >They don't believe in quality control. Milk, toys, sheetrock, all
    >FILTHY and contaminated. Shoddy workmanship all round. The ONLY
    >reason anything ever comes out of their that is marginally decent is
    >due to some Japanese control in the plants and product
    >specifications. But the poor quality we've seen in the last 3-4 years
    >shows it isn't bullet-proof.


    And yet, IIRC, they executed the guy responsible for the chemicals
    that made their way into milk that killed a bunch of kids. I wonder
    what would happen to a CEO of a company that did something like that
    here.
     
    John A., Aug 16, 2011
    #26
  7. RichA

    John A. Guest

    On Tue, 16 Aug 2011 16:23:14 +0100, Martin Brown
    <|||newspam|||@nezumi.demon.co.uk> wrote:

    >On 16/08/2011 16:08, PeterN wrote:
    >> On 8/15/2011 10:57 PM, Robert Coe wrote:
    >>> On Sun, 14 Aug 2011 19:38:07 -0400, PeterN<>
    >>> wrote:
    >>> : On 8/14/2011 5:22 PM, Robert Coe wrote:
    >>> :> On Sun, 14 Aug 2011 10:41:35 -0700 (PDT),
    >>> RichA<> wrote:
    >>> :> : Damn that contraction plastic experiences after hot molding!!
    >>> :> :
    >>> :> :
    >>> http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658
    >>> :>
    >>> :> IOW, you can make a bad product out of a good material if you cut
    >>> corners
    >>> :> or don't handle the material properly. Actually, I think we knew that,
    >>> :> but thanks anyway for reminding us. It's a dog-eat-bone world out
    >>> there,
    >>> :> and one can hardly be too careful.
    >>> :>
    >>> :
    >>> : I wonder how much effort Rich has put in to compare the coefficient of
    >>> : expansion used, with the coefficient of expansion of likely metallic.
    >>> : And if so, how they are treated in the finished product.
    >>>
    >>> I believe that some kinds of plastic are more likely to shrink than to
    >>> expand
    >>> under excess heat, as volatile substances are driven out. I wonder if the
    >>> problem is that the camera was left for hours in a broiling hot car.
    >>>

    >>
    >> that makes sense. I thought the coefficient of expansion applies to
    >> variations in temperature. You are introducing a new component. I am not
    >> an engineer. But why wouldn't the volatile substances driven out during
    >> a heat molding process. Unless, perhaps substances in the plastic change
    >> characteristics over time and become volatile.

    >
    >Depends critically on the plastic. Some do contain a trace amount of
    >unreacted monomer that gradually escapes as the material ages. New car
    >smell is a mix of various plasticisers and traces of monomer.
    >
    >Most precision engineering plastics are heavily filled composite
    >materials with properties that are *much* better than raw plastic.
    >
    >What typically happens in a hot car is that very gradually the
    >plasticisers come out of any flexible bits of plastic and they gradually
    >become more brittle. A fate which is accelerated by UV exposure. The
    >thin layer of gunge that condenses on the inside of the windscreen is a
    >mixture of those plasticisers and human skin oils.


    Plus the odd sneeze and spray from soda cans. Plus smoke in some
    cases.
     
    John A., Aug 16, 2011
    #27
  8. RichA

    Robert Coe Guest

    On Tue, 16 Aug 2011 11:08:36 -0400, PeterN <>
    wrote:
    : On 8/15/2011 10:57 PM, Robert Coe wrote:
    : > On Sun, 14 Aug 2011 19:38:07 -0400, PeterN<>
    : > wrote:
    : > : On 8/14/2011 5:22 PM, Robert Coe wrote:
    : > :> On Sun, 14 Aug 2011 10:41:35 -0700 (PDT), RichA<> wrote:
    : > :> : Damn that contraction plastic experiences after hot molding!!
    : > :> :
    : > :> : http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658
    : > :>
    : > :> IOW, you can make a bad product out of a good material if you cut corners
    : > :> or don't handle the material properly. Actually, I think we knew that,
    : > :> but thanks anyway for reminding us. It's a dog-eat-bone world out there,
    : > :> and one can hardly be too careful.
    : > :>
    : > :
    : > : I wonder how much effort Rich has put in to compare the coefficient of
    : > : expansion used, with the coefficient of expansion of likely metallic.
    : > : And if so, how they are treated in the finished product.
    : >
    : > I believe that some kinds of plastic are more likely to shrink than to expand
    : > under excess heat, as volatile substances are driven out. I wonder if the
    : > problem is that the camera was left for hours in a broiling hot car.
    : >
    :
    : that makes sense. I thought the coefficient of expansion applies to
    : variations in temperature. You are introducing a new component. I am not
    : an engineer. But why wouldn't the volatile substances be driven out during
    : a heat molding process. Unless, perhaps substances in the plastic change
    : characteristics over time and become volatile.

    There's that, and the fact that the heat molding process is quick, and the
    part is probably plunged into cold water to cool it before it can deform.

    Bob
     
    Robert Coe, Aug 17, 2011
    #28
  9. RichA

    RichA Guest

    On Aug 16, 4:14 pm, John A. <> wrote:
    > On Tue, 16 Aug 2011 05:52:58 -0700 (PDT), RichA <>
    > wrote:
    >
    >
    >
    >
    >
    >
    >
    >
    >
    > >On Aug 15, 7:20 pm, PeterN <> wrote:
    > >> On 8/14/2011 11:50 PM, Rich wrote:

    >
    > >> > PeterN<>  wrote in news:4e481427$0$12461
    > >> > $-secrets.com:

    >
    > >> >> On 8/14/2011 1:41 PM, RichA wrote:
    > >> >>> Damn that contraction plastic experiences after hot molding!!

    >
    > >> >>>http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658

    >
    > >> >> Is shoddy manufacturing, or the material used?

    >
    > >> > Could be that, partly.  Panasonic shifted solid production from Japan to
    > >> > China.

    >
    > >> It's in their blood, right?

    >
    > >> --
    > >> Peter

    >
    > >They don't believe in quality control.  Milk, toys, sheetrock, all
    > >FILTHY and contaminated.  Shoddy workmanship all round.  The ONLY
    > >reason anything ever comes out of their that is marginally decent is
    > >due to some Japanese control in the plants and product
    > >specifications.  But the poor quality we've seen in the last 3-4 years
    > >shows it isn't bullet-proof.

    >
    > And yet, IIRC, they executed the guy responsible for the chemicals
    > that made their way into milk that killed a bunch of kids. I wonder
    > what would happen to a CEO of a company that did something like that
    > here.


    The only reason they acted on it was that the World now watches them
    and their fear of exporting their garbage and killing foreigners (and
    their markets) pushed them to act. They killed 50 million of their
    own people in the 1950's, life is cheap there.
     
    RichA, Aug 17, 2011
    #29
  10. RichA

    RichA Guest

    On Aug 16, 11:23 am, Martin Brown <|||>
    wrote:
    > On 16/08/2011 16:08, PeterN wrote:
    >
    >
    >
    >
    >
    >
    >
    >
    >
    > > On 8/15/2011 10:57 PM, Robert Coe wrote:
    > >> On Sun, 14 Aug 2011 19:38:07 -0400, PeterN<>
    > >> wrote:
    > >> : On 8/14/2011 5:22 PM, Robert Coe wrote:
    > >> :> On Sun, 14 Aug 2011 10:41:35 -0700 (PDT),
    > >> RichA<> wrote:
    > >> :> : Damn that contraction plastic experiences after hot molding!!
    > >> :> :
    > >> :> :
    > >>http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658
    > >> :>
    > >> :> IOW, you can make a bad product out of a good material if you cut
    > >> corners
    > >> :> or don't handle the material properly. Actually, I think we knew that,
    > >> :> but thanks anyway for reminding us. It's a dog-eat-bone world out
    > >> there,
    > >> :> and one can hardly be too careful.
    > >> :>
    > >> :
    > >> : I wonder how much effort Rich has put in to compare the coefficient of
    > >> : expansion used, with the coefficient of expansion of likely metallic..
    > >> : And if so, how they are treated in the finished product.

    >
    > >> I believe that some kinds of plastic are more likely to shrink than to
    > >> expand
    > >> under excess heat, as volatile substances are driven out. I wonder if the
    > >> problem is that the camera was left for hours in a broiling hot car.

    >
    > > that makes sense. I thought the coefficient of expansion applies to
    > > variations in temperature. You are introducing a new component. I am not
    > > an engineer. But why wouldn't the volatile substances driven out during
    > > a heat molding process. Unless, perhaps substances in the plastic change
    > > characteristics over time and become volatile.

    >
    > Depends critically on the plastic. Some do contain a trace amount of
    > unreacted monomer that gradually escapes as the material ages. New car
    > smell is a mix of various plasticisers and traces of monomer.
    >
    > Most precision engineering plastics are heavily filled composite
    > materials with properties that are *much* better than raw plastic.
    >
    > What typically happens in a hot car is that very gradually the
    > plasticisers come out of any flexible bits of plastic and they gradually
    > become more brittle. A fate which is accelerated by UV exposure. The
    > thin layer of gunge that condenses on the inside of the windscreen is a
    > mixture of those plasticisers and human skin oils.
    >
    > Something like a bubble pack for hifi leads or batteries that is blow
    > moulded from thin thermoplastic sheet will revert to a somewhat mangled
    > version its original unstressed shape if you pour boiling water on it.
    > Crosslinked thermoset polymer like epoxy will hold its shape whatever.
    >
    > Regards,
    > Martin Brown


    I've seen reports that fillers (glass, fibers of various kinds) can
    actually make some plastics weaker than if the plastic alone was
    used. I can see where specifically laid-down layers of high-strength
    carbon fiber or boron used in conjunction with an epoxy binder would
    be very strong and rigid, but fibers of glass, mixed-in with the
    plastic in a haphazard way doesn't impress.
     
    RichA, Aug 17, 2011
    #30
  11. On Aug 17, 7:39 am, RichA <> wrote:

    > I've seen reports that fillers (glass, fibers of various kinds) can
    > actually make some plastics weaker than if the plastic alone was
    > used.  I can see where specifically laid-down layers of high-strength
    > carbon fiber or boron used in conjunction with an epoxy binder would
    > be very strong and rigid, but fibers of glass, mixed-in with the
    > plastic in a haphazard way doesn't impress.


    But what you describe is pretty much the standard
    way to make "fiberglass", as used in boats and
    airplanes and cars and photo sinks and even
    windows (not the transparent part!). Some of
    them work harder on orienting the fiber part of
    the mixture than others, as I understand it.
     
    David Dyer-Bennet, Aug 17, 2011
    #31
  12. RichA

    PeterN Guest

    On 8/17/2011 8:35 AM, RichA wrote:
    > On Aug 16, 4:14 pm, John A.<> wrote:
    >> On Tue, 16 Aug 2011 05:52:58 -0700 (PDT), RichA<>
    >> wrote:


    >>> On Aug 15, 7:20 pm, PeterN<> wrote:
    >>>> On 8/14/2011 11:50 PM, Rich wrote:

    >>
    >>>>> PeterN<> wrote in news:4e481427$0$12461
    >>>>> $-secrets.com:

    >>
    >>>>>> On 8/14/2011 1:41 PM, RichA wrote:
    >>>>>>> Damn that contraction plastic experiences after hot molding!!

    >>
    >>>>>>> http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658

    >>
    >>>>>> Is shoddy manufacturing, or the material used?

    >>
    >>>>> Could be that, partly. Panasonic shifted solid production from Japan to
    >>>>> China.

    >>
    >>>> It's in their blood, right?

    >>
    >>>> --
    >>>> Peter

    >>
    >>> They don't believe in quality control. Milk, toys, sheetrock, all
    >>> FILTHY and contaminated. Shoddy workmanship all round. The ONLY
    >>> reason anything ever comes out of their that is marginally decent is
    >>> due to some Japanese control in the plants and product
    >>> specifications. But the poor quality we've seen in the last 3-4 years
    >>> shows it isn't bullet-proof.

    >>
    >> And yet, IIRC, they executed the guy responsible for the chemicals
    >> that made their way into milk that killed a bunch of kids. I wonder
    >> what would happen to a CEO of a company that did something like that
    >> here.

    >
    > The only reason they acted on it was that the World now watches them
    > and their fear of exporting their garbage and killing foreigners (and
    > their markets) pushed them to act. They killed 50 million of their
    > own people in the 1950's, life is cheap there.


    How many native Canadians did you ancestors kill?

    Way are the Chinese different from any other people? Please explain. Is
    it in their blood? Is it that they eat too much Chinese food?

    Just answer the question without avoidance.


    --
    Peter
     
    PeterN, Aug 17, 2011
    #32
  13. RichA

    PeterN Guest

    On 8/17/2011 8:39 AM, RichA wrote:
    > On Aug 16, 11:23 am, Martin Brown<|||>
    > wrote:
    >> On 16/08/2011 16:08, PeterN wrote:
    >>
    >>
    >>
    >>
    >>
    >>
    >>
    >>
    >>
    >>> On 8/15/2011 10:57 PM, Robert Coe wrote:
    >>>> On Sun, 14 Aug 2011 19:38:07 -0400, PeterN<>
    >>>> wrote:
    >>>> : On 8/14/2011 5:22 PM, Robert Coe wrote:
    >>>> :> On Sun, 14 Aug 2011 10:41:35 -0700 (PDT),
    >>>> RichA<> wrote:
    >>>> :> : Damn that contraction plastic experiences after hot molding!!
    >>>> :> :
    >>>> :> :
    >>>> http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658
    >>>> :>
    >>>> :> IOW, you can make a bad product out of a good material if you cut
    >>>> corners
    >>>> :> or don't handle the material properly. Actually, I think we knew that,
    >>>> :> but thanks anyway for reminding us. It's a dog-eat-bone world out
    >>>> there,
    >>>> :> and one can hardly be too careful.
    >>>> :>
    >>>> :
    >>>> : I wonder how much effort Rich has put in to compare the coefficient of
    >>>> : expansion used, with the coefficient of expansion of likely metallic.
    >>>> : And if so, how they are treated in the finished product.

    >>
    >>>> I believe that some kinds of plastic are more likely to shrink than to
    >>>> expand
    >>>> under excess heat, as volatile substances are driven out. I wonder if the
    >>>> problem is that the camera was left for hours in a broiling hot car.

    >>
    >>> that makes sense. I thought the coefficient of expansion applies to
    >>> variations in temperature. You are introducing a new component. I am not
    >>> an engineer. But why wouldn't the volatile substances driven out during
    >>> a heat molding process. Unless, perhaps substances in the plastic change
    >>> characteristics over time and become volatile.

    >>
    >> Depends critically on the plastic. Some do contain a trace amount of
    >> unreacted monomer that gradually escapes as the material ages. New car
    >> smell is a mix of various plasticisers and traces of monomer.
    >>
    >> Most precision engineering plastics are heavily filled composite
    >> materials with properties that are *much* better than raw plastic.
    >>
    >> What typically happens in a hot car is that very gradually the
    >> plasticisers come out of any flexible bits of plastic and they gradually
    >> become more brittle. A fate which is accelerated by UV exposure. The
    >> thin layer of gunge that condenses on the inside of the windscreen is a
    >> mixture of those plasticisers and human skin oils.
    >>
    >> Something like a bubble pack for hifi leads or batteries that is blow
    >> moulded from thin thermoplastic sheet will revert to a somewhat mangled
    >> version its original unstressed shape if you pour boiling water on it.
    >> Crosslinked thermoset polymer like epoxy will hold its shape whatever.
    >>
    >> Regards,
    >> Martin Brown

    >
    > I've seen reports that fillers (glass, fibers of various kinds) can
    > actually make some plastics weaker than if the plastic alone was
    > used. I can see where specifically laid-down layers of high-strength
    > carbon fiber or boron used in conjunction with an epoxy binder would
    > be very strong and rigid, but fibers of glass, mixed-in with the
    > plastic in a haphazard way doesn't impress.


    Why do I trust Martin's analysis?
    Why do I not trust your unsupported statement?
    --
    Peter
     
    PeterN, Aug 17, 2011
    #33
  14. RichA

    Ray Fischer Guest

    RichA <> wrote:
    >Damn that contraction plastic experiences after hot molding!!


    Metal contracts after "hot molding", dumbass.

    --
    Ray Fischer | Mendocracy (n.) government by lying
    | The new GOP ideal
     
    Ray Fischer, Aug 17, 2011
    #34
  15. RichA

    Ray Fischer Guest

    RichA <> wrote:
    >People need to understand that a frigging jetplane isn't using the
    >plastic scrap used in a cheap camera body. Example: A carbon fiber
    >tube, aircraft grade, 2" wide and about 4ft long costs about $500.00.
    >The polycarbone scrap used in the cameras is about 1/1,000th of that
    >cost. The two also have VASTLY different structure. So WHY are you
    >people comparing the two, there is no KINSHIP between them!


    Smirk. Rich doesn't care if it's plastic. He just wants it to be
    expensive so that he can feel good about how much money he spent.

    --
    Ray Fischer | Mendocracy (n.) government by lying
    | The new GOP ideal
     
    Ray Fischer, Aug 17, 2011
    #35
  16. RichA

    John A. Guest

    On Wed, 17 Aug 2011 10:01:52 -0400, PeterN
    <> wrote:

    >On 8/17/2011 8:35 AM, RichA wrote:
    >> On Aug 16, 4:14 pm, John A.<> wrote:
    >>> On Tue, 16 Aug 2011 05:52:58 -0700 (PDT), RichA<>
    >>> wrote:

    >
    >>>> On Aug 15, 7:20 pm, PeterN<> wrote:
    >>>>> On 8/14/2011 11:50 PM, Rich wrote:
    >>>
    >>>>>> PeterN<> wrote in news:4e481427$0$12461
    >>>>>> $-secrets.com:
    >>>
    >>>>>>> On 8/14/2011 1:41 PM, RichA wrote:
    >>>>>>>> Damn that contraction plastic experiences after hot molding!!
    >>>
    >>>>>>>> http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658
    >>>
    >>>>>>> Is shoddy manufacturing, or the material used?
    >>>
    >>>>>> Could be that, partly. Panasonic shifted solid production from Japan to
    >>>>>> China.
    >>>
    >>>>> It's in their blood, right?
    >>>
    >>>>> --
    >>>>> Peter
    >>>
    >>>> They don't believe in quality control. Milk, toys, sheetrock, all
    >>>> FILTHY and contaminated. Shoddy workmanship all round. The ONLY
    >>>> reason anything ever comes out of their that is marginally decent is
    >>>> due to some Japanese control in the plants and product
    >>>> specifications. But the poor quality we've seen in the last 3-4 years
    >>>> shows it isn't bullet-proof.
    >>>
    >>> And yet, IIRC, they executed the guy responsible for the chemicals
    >>> that made their way into milk that killed a bunch of kids. I wonder
    >>> what would happen to a CEO of a company that did something like that
    >>> here.

    >>
    >> The only reason they acted on it was that the World now watches them
    >> and their fear of exporting their garbage and killing foreigners (and
    >> their markets) pushed them to act. They killed 50 million of their
    >> own people in the 1950's, life is cheap there.

    >
    >How many native Canadians did you ancestors kill?
    >
    >Way are the Chinese different from any other people? Please explain. Is
    >it in their blood? Is it that they eat too much Chinese food?


    I think over there they just call it food.
     
    John A., Aug 17, 2011
    #36
  17. RichA

    PeterN Guest

    On 8/17/2011 11:06 PM, Rich wrote:
    > PeterN<> wrote in
    > news:4e4a896c$0$12479$-secrets.com:
    >
    >> On 8/16/2011 8:59 AM, RichA wrote:
    >>> On Aug 15, 7:20 pm, PeterN<> wrote:
    >>>> On 8/14/2011 11:50 PM, Rich wrote:
    >>>>
    >>>>> PeterN<> wrote in
    >>>>> news:4e481427$0$12461 $-secrets.com:
    >>>>
    >>>>>> On 8/14/2011 1:41 PM, RichA wrote:
    >>>>>>> Damn that contraction plastic experiences after hot molding!!
    >>>>
    >>>>>>> http://forums.dpreview.com/forums/read.asp?forum=1041&message=3911
    >>>>>>> 1658
    >>>>
    >>>>>> Is shoddy manufacturing, or the material used?
    >>>>
    >>>>> Could be that, partly. Panasonic shifted solid production from
    >>>>> Japan to China.
    >>>>
    >>>> It's in their blood, right?
    >>>
    >>> Only heavy metals and effluents from burned plastic. China is a
    >>> polluted cess-pit.
    >>>
    >>>

    >>
    >> No other people have ever done that, right?
    >> Only the Chinese?
    >>
    >> Must be the folk that set the Cuyahoga on fire ate too much Chinese
    >> food.
    >>
    >>

    >
    > Sorry, is this ancient history week? Did you know the Romans fed people
    > to wild animals?


    And that has what to do with Chinese people? The Cuyahoga fire took
    place long after China had a Communist regime.

    --
    Peter
     
    PeterN, Aug 18, 2011
    #37
  18. RichA

    Robert Coe Guest

    On Tue, 16 Aug 2011 11:04:18 -0400, PeterN <>
    wrote:
    : On 8/16/2011 8:57 AM, RichA wrote:
    : > On Aug 15, 7:59 pm, PeterN<> wrote:
    : >> to clarify my prior response.
    : >>
    : >> What adjustments are needed for the coefficient of expansion for each of
    : >> the materials, when removing them from the mold?
    : >>
    : >> --
    : >> Peter
    : >
    : > You are assuming the mold is actually any good and the problem isn't
    : > happening there, with the equipment. 20 years ago, an optics firm in
    : > California was turning out terrible products because old mold masters
    : > were worn. Didn't fix the problem until they replaced them.
    : > Half the Chinese production used to be (still?) done in their
    : > backyards over bonfires. That's how they render down old electronics
    : > to scavenge metals to this day.
    :
    : I am assuming that you would answer my question.

    How long have you been in this newsgroup, Peter? :^)

    Bob
     
    Robert Coe, Aug 19, 2011
    #38
  19. RichA

    PeterN Guest

    On 8/19/2011 10:30 AM, Robert Coe wrote:
    > On Tue, 16 Aug 2011 11:04:18 -0400, PeterN<>
    > wrote:
    > : On 8/16/2011 8:57 AM, RichA wrote:
    > :> On Aug 15, 7:59 pm, PeterN<> wrote:
    > :>> to clarify my prior response.
    > :>>
    > :>> What adjustments are needed for the coefficient of expansion for each of
    > :>> the materials, when removing them from the mold?
    > :>>
    > :>> --
    > :>> Peter
    > :>
    > :> You are assuming the mold is actually any good and the problem isn't
    > :> happening there, with the equipment. 20 years ago, an optics firm in
    > :> California was turning out terrible products because old mold masters
    > :> were worn. Didn't fix the problem until they replaced them.
    > :> Half the Chinese production used to be (still?) done in their
    > :> backyards over bonfires. That's how they render down old electronics
    > :> to scavenge metals to this day.
    > :
    > : I am assuming that you would answer my question.
    >
    > How long have you been in this newsgroup, Peter? :^)
    >
    > Bob



    Did I really need <\end sarcastic tag> ?

    --
    Peter
     
    PeterN, Aug 19, 2011
    #39
  20. RichA

    Robert Coe Guest

    On Wed, 17 Aug 2011 05:35:41 -0700 (PDT), RichA <> wrote:
    : On Aug 16, 4:14 pm, John A. <> wrote:
    : > On Tue, 16 Aug 2011 05:52:58 -0700 (PDT), RichA <>
    : > wrote:
    : >
    : >
    : >
    : >
    : >
    : >
    : >
    : >
    : >
    : > >On Aug 15, 7:20 pm, PeterN <> wrote:
    : > >> On 8/14/2011 11:50 PM, Rich wrote:
    : >
    : > >> > PeterN<>  wrote in news:4e481427$0$12461
    : > >> > $-secrets.com:
    : >
    : > >> >> On 8/14/2011 1:41 PM, RichA wrote:
    : > >> >>> Damn that contraction plastic experiences after hot molding!!
    : >
    : > >> >>>http://forums.dpreview.com/forums/read.asp?forum=1041&message=39111658
    : >
    : > >> >> Is shoddy manufacturing, or the material used?
    : >
    : > >> > Could be that, partly.  Panasonic shifted solid production from Japan to
    : > >> > China.
    : >
    : > >> It's in their blood, right?
    : >
    : > >> --
    : > >> Peter
    : >
    : > >They don't believe in quality control.  Milk, toys, sheetrock, all
    : > >FILTHY and contaminated.  Shoddy workmanship all round.  The ONLY
    : > >reason anything ever comes out of their that is marginally decent is
    : > >due to some Japanese control in the plants and product
    : > >specifications.  But the poor quality we've seen in the last 3-4 years
    : > >shows it isn't bullet-proof.
    : >
    : > And yet, IIRC, they executed the guy responsible for the chemicals
    : > that made their way into milk that killed a bunch of kids. I wonder
    : > what would happen to a CEO of a company that did something like that
    : > here.
    :
    : The only reason they acted on it was that the World now watches them
    : and their fear of exporting their garbage and killing foreigners (and
    : their markets) pushed them to act. They killed 50 million of their
    : own people in the 1950's, life is cheap there.

    Is that the opinion of the Chinese people or just your take on the issue? How
    many people did you talk to about it, the last time you were there? Are you
    now proficient enough in Mandarin to converse on the street in Beijing without
    a translator, or are you still fluent only in Cantonese?

    Bob
     
    Robert Coe, Aug 20, 2011
    #40
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. joevan

    Dell strikes again.

    joevan, Aug 20, 2005, in forum: Computer Support
    Replies:
    27
    Views:
    1,265
    beachman
    Aug 22, 2005
  2. Kyler Laird

    Nufone strikes again...

    Kyler Laird, Jul 24, 2006, in forum: VOIP
    Replies:
    1
    Views:
    528
    Jonathan Roberts
    Jul 24, 2006
  3. Annika1980

    FORGOTTEN 400 STRIKES AGAIN !!!

    Annika1980, Sep 2, 2004, in forum: Digital Photography
    Replies:
    0
    Views:
    439
    Annika1980
    Sep 2, 2004
  4. Roger N. Clark (change username to rnclark)

    TSA strikes again

    Roger N. Clark (change username to rnclark), Dec 9, 2005, in forum: Digital Photography
    Replies:
    227
    Views:
    3,552
    Nikon User
    Dec 19, 2005
  5. Mike_P

    The Empire Strikes Again !

    Mike_P, Oct 29, 2004, in forum: NZ Computing
    Replies:
    21
    Views:
    952
    Bruce Sinclair
    Nov 2, 2004
Loading...

Share This Page