injection molding-sformo

[Mocca]

Hello, Lucaluca. I add to my tail to say mine.
for the corners of molding is just what mold inventor says.
if the piece to be realized does not need photo engraving or embossing then the strip angle can be minimum (1°) considering a limited height; the more the piece to be realized becomes high / background the more the strip must be increased (see plastic buckets).
As far as your last question is concerned, I can tell you that, as my predecessors have already rightly said, once the frontal surface is calculated in cm2 and multiplied by the specific pressure of the material (if you are on the 500 six in safety) that is the closing force necessary to keep the mold closed during the injection of the material, i.e. you discard the most suitable press to print your piece.
the presses are roughly divided according to the tons.
example: frontal sup. 50 cm2; pressure 500 kg/cm2... 50x500=25000kg=25 tonn. ....you must use a minimum press 25 tonn. You can't print your piece on a 3000 tonn press for no reason:
1 the mould you will conceive will be dimensionally too small for that press;
2nd the injection part of the press provides too much material for what you need (I leave the various technicalities in this regard)
3rd the hourly cost of the press is excessive. large way the hourly cost of a press is comparable to its size i.e. press from 1000 tonn....costa about 100 euro/hour.
for the various specifications to be inserted in the press, in the molding phase, you will need to refer to the tables of the material you have chosen and especially to the experience of the printer that will know perfectly its press. Finally each press can print different types of material; In this case the printer will have to change something to make it feasible but to the designer these things little interest. before
start conceiving the mold dimensionally you will need to have a pattern of the press that will be used for molding.
Good things cumpà.

 

[tecnico_plast]

The best machine if with a material or another.. If you mean what you didn't understand... I tell you no one understood it in college...)

There is no machine better than another based on material.

based on the material projects the piece, then the mold, and set the stamping parameters accordingly (there are whole books that treat these problems, not simple stuff).

It's the usual history of the university, prof. throw on the table a series of formulas and definitions, and they claim that the boys understand us something, without even knowing what they are talking about, but maybe they don't even know it.

 

[Dade73]

hi luca, I agree with the use of a press with closing force >=15 ton., I cannot understand from your question if you need info about : t. cycle, costs .... etc.; pp and pe-hd are both polyolefine and do not require particular characteristics to the press, in case you drink to make self-coloration of the material and the number of pz/h. both high is good to push the plasticification of the machine, using barrier screws and with l/d >21 ratios.
Bye-bye

 

[SHIREN]

Hello, Lucaluca. I add to my tail to say mine.
for the corners of molding is just what mold inventor says.
if the piece to be realized does not need photo engraving or embossing then the strip angle can be minimum (1°) considering a limited height; the more the piece to be realized becomes high / background the more the strip must be increased (see plastic buckets).

Good things cumpà.

Bye-bye.
I say that in terms of deformity it would be better to say how many mm
I need to extract a piece
which then become grade is in normal calculation practice
talk about specific regulations that indicate precise corners of sforms for
particulars with photoincisions or embossing seems to me an excessive moment
in fact if you read the various posts
you say a(1°)
other users say three(3°)
grit thousand

 

[Mould Inventor]

Then maybe we don't understand each other.

when they do quality control and test the mold, if there are interventions on the mold, for example photo engraving, (but also for other issues) and the node of the matter is the sform, the technician responsible for control and testing measures the sform angle.
If the angle of deformity is greater than the angle quoted by the law is all right, they are "holy" of others, if instead the angle is lesser a tab is drafted from quality control and are your own.
but we always talk about angles because it is the control parameter.
then if you see that the height is small and so you want to "give him up" with the deformed it is fine, but it is always better to talk about angles because otherwise to the quality control they do, indeed they did, a "so much deck".
because the angle is a unique parameter, if you talk about disform on height you have to pass two parameters, h and s, because only one of the two makes no sense.
in any field, toothpick appetizing the "interprise" spaceship, you must always work with less parameters possible, less parameters = less errors; especially when drafting regulations, quality control etc. etc.

I also agree that one is worth the other.... But when they say to me,daga three millimeters de sformo" then it turns out that "I thought it was"... if we talk about angles there is no such risk.
for those who were not from the province of Brescia I can translate

 

[Mocca]

Bye-bye.
I say that in terms of deformity it would be better to say how many mm
I need to extract a piece
which then become grade is in normal calculation practice
talk about specific regulations that indicate precise corners of sforms for
particulars with photoincisions or embossing seems to me an excessive moment
in fact if you read the various posts
you say a(1°)
other users say three(3°)
grit thousand

shiren excuse but after years and years of "viziatura" of mathematical models of the details to print I never set the mm but the corners. If the customer says that the wall has to be "zero" the only thing you can do, in addition to perche on molding theories, it is to give a minimal sform angle that is, as far as I am concerned, 1st. can you give more degrees? Good for you.
and ribs, do they not have 0.5 degrees of shaping per wall?
I repeat, and it is not excessive, knowing how many degrees it takes for such embossing. if for example for a embossing of a plank it takes 4,5° of shaping what to do, calculate the mm regarding a centinated surface? believe me, at least in Turin, the molding is always set in degrees.
I do not know about it I have read the other previous posts to my who have indicated 3° (I am also young of this forum but not first hair for the design of thermoplastic molds, they will have given their correct motivations.
again I have to give reason to mould inventor who says that today you have to deal with the quality that checks, obvious if important, even the small corners of reform set.
I'm sorry if I've been oversighted about this, but I just wanted to give you my opinion.
Good things cumpà.

 

[SHIREN]

Then maybe we don't understand each other.

I'm sorry
we are on different sides
I would sincerely have the opportunity to interlocate personally
direct contact with your person to transmit what I affirm
when it comes to testing or control devices with measuring machines
I could open another discussion
advance
the role of testing is not to check if a model a mold a mechanical piece
faithfully reflects the paper design or mathematics
but it is to assess whether in the axieme of execution errors the piece that is controlling both from waste or good

in practice today has changed the status of testing
once without his signature the piece was from scrap
today is not he who decides
must only print what the measuring machine tells him
because it no longer comes from the workshop mecc. where it has been incarriage of years
immersed in the smell of emulsifying oils
but a quality control officer who took a course on the machine
of 5gg and where he repeats with so much manual to the hand what he taught him
a tudor that in turn doesn't even know what means a minimum burn from chips

I add
even with measuring machines there are probes
If you have a little manual? you can change the values that emerge
"you understand me"
a big hug

 

[SHIREN]

shiren excuse but after years and years of "viziatura" of mathematical models of the details to print I never set the mm
.

Bye-bye.
the diversity of view lies in what you write
are two different philosophies
but I struggle for prog pieces in which I have to put the corners of reform according to already defined norms and not disputeable
p.s.
but where are the rules written?
and even if there are certain general indications
where you indicate that preferably for certain types of artefacts
is "recommended" to have such sforms of such
the final end comnque and always to pull the piece from the mold without prob
The rest I know only gossip
a hug to you too
Thank you very much

 

[tecnico_plast]

I also agree that one is worth the other.... But when they say to me,daga three millimeters de sformo" then it turns out that "I thought it was"... if we talk about angles there is no such risk.
for those who were not from the province of Brescia I can translate

I find myself far enough from Brescia, I can guess that the translation is this "dia 3 mm disform", "I could think that they were so few?"

However, we also indicate the sforms with the corners, nothing that has to do with the rules, only with the functionality of the piece and the mold.

 

[stang64]

I agree with Moldova inventor and with those who speak of deformed in degrees.

Perhaps because of the practicality of realizing the mold in the deformed part speaking of millimeters it turns out to everyone immediately clearer and simpler for the setting of the job, if the tool is found all its beautiful quotas in millimeters avoid getting the contiguous that is always a risk of added error, but I agree that the deform is in degrees.

there are texts and also info on websites that talk about it and always in degrees.

Among other things, the rule, but perhaps you must already look at it, is that for every 0.025mm of engraving or embossing you must add 1st of disform to the one normally assigned to the wall, then that by experience you use from immediately 2.5° or 5°.

 

[SHIREN]

I agree with Moldova inventor and with those who speak of deformed in degrees.

perhaps because of the practicality of realizing the mold in the deformed part speaking of millimeters it turns out to everyone immediately clearer and simpler for the setting of the work,
.

:finger:
Hello stang64
what you write and only one of the reasons why I always talk about mm of puff
then it is natural that the mm become gradi°ma is (at least for me) a secondary info
a board

 

[SHIREN]

I find myself far enough from Brescia, I can guess that the translation is this "dia 3 mm disform", "I could think that they were so few?"

However, we also indicate the sforms with the corners, nothing that has to do with the rules, only with the functionality of the piece and the mold.

Hello technical_plast
I say then I can be denied
when there are rules
these must be respected
There's nothing in this profession
everything belongs to the norms you have in the "bathroom"
that you know very well! ! ! !
a greeting

 

[tecnico_plast]

Hello technical_plast
I say then I can be denied
when there are rules
these must be respected
There's nothing in this profession
everything belongs to the norms you have in the "bathroom"
that you know very well! ! ! !
a greeting

True, experience is the only rule to follow.

It is also true that every ut finds his way of working and managing the projects, the important thing is to understand who is in the workshop :smile:

Perhaps the situation changes if ut and workshop are part of different companies.