Method of predicing injection molding cycle time

Patent metadata

Field	Value
Publication number	US-9475221-B2
Application number	US-201414568323-A
Country	US
Kind code	B2
Filing date	Dec 12, 2014
Priority date	Dec 12, 2014
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

The invention features, in general, a method for determining a target cycle time for an injection molded part. The method comprises the steps of ascertaining the solidified volume percentage (V n ) as a function of cooling time (T n ) data for solidification of an injection molded part and calculating a cooling speed indicator (CSI n ) for each data point, (T n ,V n ). The solidified volume percentage (V n ) as a function of cooling time (T n ) and solidified volume percentage (V n ) as a function of cooling speed indicator (CSI n ) are tabulated and used to determine a target cycle time.

First claim

What is claimed is:

1. A method of determining a target cycle time for injection molding a production part, comprising the steps of:
a. creating a computer based model of an injection molded part;
b. creating a computer based model of a mold for an injection molded part;
c. ascertaining the solidified volume percentage (V n ) as a function of cooling time (T n ) data for solidification of the injection molded part from V 0 =0% to V total =100%;
d. calculating a cooling speed indicator (CSI n ) for each solidified volume percentage as a function of time data point (T n ,V n );
e. determining the solidified volume percentage (V n ) as a function of a cooling speed indicator (CSI n ) data, (CSI n ,V n ), from V 0 =0% to V total =100%;
f. determining a Turning Point (CSI n ,V n ) Turning Point for solidified volume percentage (V n ) as a function of a cooling speed indicator (CSI n ) data;
g. determining a target cycle time (T n ) corresponding to the solidified volume percentage (V n ) at the Turning Point; and
h. applying the target cycle time to the production molded part.

2. The method according to claim 1 wherein

CSI
n

=

(

Tn
-
Tn
-
1

)

/
Ttotal

Vn
-
Vn
-

1
/
Vtotal

.

3. The method according to claim 2 wherein the Turning Point, (CSI n ,V n ) Turning Point , is a data point, (CSI n ,V n ), having a minimum value defined by

(
CSIn
)

2

+

(

100
-
Vn

)

2

2

.

4. The method according to claim 2 further comprising the step of:
a. producing a first graph of solidified volume percentage (V n ) as a function of cooling time (T n ).

5. The method according to claim 4 further comprising the step of:
a. producing a second graph of the solidified volume percentage (V n ) as a function of a cooling speed indicator (CSI n ).

6. The method according to claim 5 further comprising the step of:
a. determining a Turning Point on the second graph for solidified volume percentage (V n ) and a cooling speed indicator (CSI n ).

7. The method according to claim 6 further comprising the step of:
a. determining a target cycle time by finding the cycle time (T n ) on the first graph corresponding to the solidified volume percentage (V n ) at the Turning Point on the second graph.

8. The method according to claim 6 wherein the Turning Point (V n , CSI n ) Turning Point is the point having a minimum distance to a data point defined by solidified volume percentage (V n )=(V total )=100% and CSI n =CSI 0 =0 wherein

distance
=

(
CSIn
)

2

+

(

100
-
Vn

)

2

2

.

9. A method of determining a target cycle time for injection molding a production part, comprising the steps of:
a. creating a computer based model of an injection molded part;
b. creating a computer based model of a mold for an injection molded part;
c. ascertaining the solidified volume percentage (V n ) as a function of cooling time (T n ) data for solidification of an injection molded part from V 0 =0% to V total =100%;
d. calculating a cooling speed indicator (CSI n ) for each solidified volume percentage as a function of time data point (T n ,V n ), where

CSI
n

=

(

Tn
-
Tn
-
1

)

/
Ttotal

Vn
-
Vn
-

1
/
Vtotal

;

e. determining the solidified volume percentage (V) as a function of a cooling speed indicator (CSI) data, (CSI,V) from V 0 =0% to V total =100% ;
f. determining a Turning Point (CSI n ,VO Turning Point for solidified volume percentage (V n ) as a function of a cooling speed indicator (CSI) data, wherein the Turning Point, (CSI n ,V n ) Turning Point , is a data point, (CSI n ,V n ), having a minimum value defined by

(
CSIn
)

2

+

(

100
-
Vn

)

2

2

;

g. determining a target cycle time (TO corresponding to the solidified volume percentage (V n ) at the Turning Point; and
h. applying the target cycle time to the production molded part.

10. The method according to claim 9 further comprising the step of:
a. producing a first graph of solidified volume percentage (V n ) as a fu

Assignees

• Procter & Gamble

Inventors

• Wang Sean

Classifications

• G06F30/20 Primary

  Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) · CPC title

• G06F2113/22

  Moulding · CPC title

• B29C2945/76892

  Solidification, setting phase · CPC title

• B29C2945/76558

  termination · CPC title

• B29C2945/76561

  duration · CPC title