Dip molding process

Claim 2

A DIP MOLDING PROCESS COMPRISING: PROVIDING A FIRST SOURCE OF A FIRST DIP MOLDING PLASTISOL HAVING A FIRST DUROMETERR RATING AND A SECOND SOURCE OF A SECOND DIP MOLDING PLASTISOL HAVING A SECOND DUROMETER RATING, HEATING A DIP MOLDING MOLD TO A TEMPERATURE HIGHER THAN THE TEMPERATURE NORMALLY REQUIRED TO DIP MOLD IN THE SECOND PLASTISOL, DIPPING SAID MOLD INTO SAID FIRST PLASTISOL A DISTANCE SUFFICIENT TO COAT ONLY A PORTION OF THE MOLD SURFACE AND FOR A TIME SUFFICIENT TO COAT SAID PORTION TO THE DESIRED THICKNESS, SUBSEQUENTLY DIPPING THE PARTIALLY COATED MOLD INTO THE SECOND PLASTISOL A DISTANCE GREATER THAN SAID PORTION AND FOR A TIME SUFFICIENT TO COAT THE FIRST COATED PORTION AND THE PORTIONS OF SAID MOLD NOT ALREADY COATED TO A DESIRED THICKNESS, DELAYING THE INITIATION OF SAID SUBSEQUENTLY DIP INTO SECOND PLASTISOL FOR A PERIOD OF TIME OF APPROXIMATELY 30 TO 90 SECONDS AFTER SAID MOLD LEAVES SAID FIRST PLASTISOL AND MAINTAINING SAID MOLD IN AN ATMOSPHERE COOLER THAN THE TEMPERATURE OF SAID MOLD DURING SAID DELAYING STEP TO ALLOW THE FIRST COATING OF PLASTISOL ON SAID MOLD TO GELL SOMEWHAT AND ALLOWING THE SURFACE OF SAID COATING TO COOL SOMEWHAT PRIOR TO ININTIATION OF SAID SUBSEQUENT DIP, AND SUBSEQUENTLY REMOVING THE RESULTING MOLDED ARTICLE FROM SAID MOLD.

Claim 3

The dip molding process of claim 1 comprising: heating said mold to a temperature approximately 15* to 45* F. higher than the temperature normally required to dip into

Claim 4

The dip molding process of claim 3 comprising: dipping said mold into said second plastisol in approximately 1 minute of the time said mold leaves said first plastisol.

Claim 5

The dip molding process of claim 2 which comprises: dipping said mold into said first plastisol approximately 10 to 30 seconds less than one would normally dip into said first plastisol.

Claim 6

The dip molding process of claim 2 comprising: dipping said mold into said second plastisol sufficiently soon after it leaves said first plastisol that the temperature of said mold drops only approximately 30* F. from the time at which it is first dipped into said first plastisol and the time that it is first dipped into said second plastisol.

Claim 7

The dip molding process of claim 5 in which said first plastisol has a durometer rating of no greater than approximately 95 on the Shore A scale and said second plastisol has a different durometer rating of no less than approximately 70 on the Shore A scale.

Claim 8

The dip molding process of claim 5 in which said first plastisol has a durometer rating of no less then approximately 70 on the Shore A scale and said second plastisol has a different durometer rating of no greater than approximately 95 on the Shore A scale.

Claim 9

The dip molding process of claim 1 in which said mold is heated to a temperature sufficiently high to allow for the heat loss which will be experienced from the time said mold is first dipped into said first plastisol until the time said mold is first dipped into said second plastisol.

Claim 10

The process of claim 1 comprising: providing at least said first plastisol of a composition which gels to a roughened surface shortly after dipping is completed.

Claim 11

The process of claim 1 comprising: providing said first plastisol of a mixture of first resin particles having an average particle size of less than 500 microns, a similar resin having particles whose size with relationship to said first resin particles is in the range of approximately 6.5 to 1 to 200 to 1, and a suitable plasticizer.

Claim 12

The process of claim 1 comprising: providing first and second plastisols of a mixture of first resin particles having an average particle size of less than 500 microns, a similar resin having particles whose size with relationship to said first resin particles is in the range of approximately 6.5 to 1 to 200 to 1, and a suitable plasticizer.

Claim 13

A dip molding process comprising: providing a first source of a first dip molding plastisol having a first durometer rating and a second source of a second dip molding plastisol having a second durometer rating; positioning said first and second sources adjacent one another; providing conveying means for conveying molds to and from said first and second sources; positioning a plurality of sets of molds, each set having at least one mold therein, on said conveying means at spaced intervals, each interval from center to center being approximately the same as the spacing between the centers of said frst and second sources; providing means for differentially varying the dip times for said first and second sources; setting the dip time for said second source for a length of time sufficient to coat a mold to the desired thickness without any undersirable dripping, running, or bubbling; setting the dip time of said first source foR a shorter length of time then the dip time of said second source, sufficient only to coat a portion of the mold to a desired thickness and sufficiently short to create a delay from the time a set of molds leaves said first source until it enters said second source; conveying said sets of molds through an oven at a temperature and for a time sufficient to preheat said molds to a temperature higher than the temperature normally required to dip mold in said second plastisol and sufficiently high to allow for the heat loss which will be experienced from the time a mold is first dipped into said first source until it is first dipped into said second source whereby when a mold is finally dipped into said second source, it will have sufficient heat to acquire an adequate plastic coating; conveying said sets of molds to said first and second sources; generally simultaneously initiating the dipping of adjacent sets of molds in said first and second sources and sequentially dipping each set of molds first into said first source and then into said second source whereby a portion of each mold will be first coated with said first plastisol in said first source while the coated portion and uncoated portion of said mold will be coated in said second source; and subsequently removing the resulting molded article from said mold.

Claim 14

A dip molding process comprising: providing a first source of a first dip molding plastisol having a first durometer rating and a second source of a second dip molding plastisol having a second durometer rating; positioning said first and second sources adjacent one another; providing conveying means for conveying molds to and from said first and second sources; positioning a plurality of sets of molds, each set having at least one mold therein, on said conveying means at spaced intervals, each interval from center to center being approximately the same as the spacing between the centers of said frst and second sources; providing means for differentially varying the dip times for said first and second sources; setting the dip time for said second source for a length of time sufficient to coat a mold to the desired thickness without any undersirable dripping, running, or bubbling; setting the dip time of said first source foR a shorter length of time then the dip time of said second source, sufficient only to coat a portion of the mold to a desired thickness and sufficiently short to create a delay from the time a set of molds leaves said first source until it enters said second source; conveying said sets of molds through an oven at a temperature and for a time sufficient to preheat said molds to a temperature higher than the temperature normally required to dip mold in said second plastisol and sufficiently high to allow for the heat loss which will be experienced from the time a mold is first dipped into said first source until it is first dipped into said second source whereby when a mold is finally dipped into said second source, it will have sufficient heat to acquire an adequate plastic coating; conveying said sets of molds to said first and second sources; generally simultaneously initiating the dipping of adjacent sets of molds in said first and second sources and sequentially dipping each set of molds first into said first source and then into said second source whereby a portion of each mold will be first coated with said first plastisol in said first source while the coated portion and uncoated portion of said mold will be coated in said second source; and subsequently removing the resulting molded article from said mold.

Claim 15

The process of claim 12 in which said mold is maintained in an atmosphere cooler than the temperature of said mold during the delay between the end of the dip into the first plastisol until the initiation of the dip into the second plastisol, whereby the surface of the first coating of plastisol on said mold has an opportunity to cool somewhat prior to initiation of said subsequent dip.

Claim 16

The dip molding process of claim 12 comprising: heating said mold to a temperature approximately 15* to 45* F. higher than the temperature normally required to dip into the second plastisol.

Claim 17

The dip molding process of claim 14 comprising dipping said mold into said second plastisol approximately 30 to 90 seconds after said mold leaves said first plastisol.

Claim 18

The dip molding process of claim 14 comprising: dipping said mold into said second plastisol in approximately one minute of the time said mold leaves said first plastisol.

Claim 19

The dip molding process of claim 14 which comprises: dipping said mold into said first plastisol approximately 10 to 30 seconds less than one would normally dip into said first plastisol.

Claim 20

The dip molding process of claim 14 comprising: dipping said mold into said second plastisol sufficiently soon after it leaves said first plastisol that the temperature of said mold drops only approximately 30* F. from the time at which it is first dipped into said first plastisol and the time that it is first dipped into said second plastisol.

Claim 21

The dip molding process of claim 18 in which said first plastisol has a different durometer rating of no greater the approximately 95 on the Shore A scale and said second plastisol has a durometer rating of no less than approximately 70 on the Shore A scale.

Claim 22

The dip molding process of claim 18 in which said first plastisol has a durometer rating of no less than approximately 70 on the Shore A scale and said second plastisol has a different rating of no greater than approximately 95 on the Shore A scale.

Claim 23

The process of claim 12 comprising: providing at least said first plastisol of a composition which gels to a roughened surface shortly after dipping is completed.

Claim 24

The process of claim 12 comprising: providing said first plastisol of a mixture of first resin particles having an average particle size of less than 500 microns, a similar resin having particles whose size with relationship to said first resin particles is in the range of approximately 6.5 to 1 to 200 to 1, and a suitable plasticizer.

Claim 25

The process of claim 22 in which said second plastisol is the same as said first plastisol.

Claim 26

A dip molding process comprising: providing a first source of a first dip molding plastisol having a durometer rating of no less than approximately 70 on the Shore A scale; providing a second source of a second dip molding plastisol having a different durometer rating of no greater than approximately 95 on the Shore A scale; preheating a dip molding to a temperature higher than the temperature normally required to dip mold in the second plastisol and sufficiently high to allow for the heat loss which will be experienced from the time a mold is first dipped into said first source until the time at which it is subsequently dipped into said second source whereby when a mold is finally dipped into said second source, it will have sufficient heat to acquire a satisfactory plastic coating; dipping a portion of said mold into said first plastisol at a dip rate substantially faster than one would normally dip into said first plastisol; subsequently dipping said mold into the second plastisol a distance greater then said portion for a time sufficient to coat the coated portion and noncoated portions of said mold to a desired thickness; delaying the initiation of said subsequent dip into said second plastisol for a period of time following said first dip into said first plastisol sufficient to allow the first coating of plastisol on said mold to gel somewhat and allowing the surface of said first coating to cool somewhat prior to initiation of said subsequent dip; and subsequently removing the resulting molded article from said mold.

Claim 27

A dip molding process comprising: providing a first source of a first dip molding plastisol having a durometer rating of no less than approximately 70 on the Shore A scale; providing a second source of a second dip molding plastisol having a different durometer rating of no greater than approximately 95 on the Shore A scale; preheating a dip molding to a temperature higher than the temperature normally required to dip mold in the second plastisol and sufficiently high to allow for the heat loss which will be experienced from the time a mold is first dipped into said first source until the time at which it is subsequently dipped into said second source whereby when a mold is finally dipped into said second source, it will have sufficient heat to acquire a satisfactory plastic coating; dipping a portion of said mold into said first plastisol at a dip rate substantially faster than one would normally dip into said first plastisol; subsequently dipping said mold into the second plastisol a distance greater then said portion for a time sufficient to coat the coated portion and noncoated portions of said mold to a desired thickness; delaying the initiation of said subsequent dip into said second plastisol for a period of time following said first dip into said first plastisol sufficient to allow the first coating of plastisol on said mold to gel somewhat and allowing the surface of said first coating to cool somewhat prior to initiation of said subsequent dip; and subsequently removing the resulting molded article from said mold.

Claim 28

The dip molding process of claim 24 comprising: heating said mold to a temperature approximately 15* to 45* F. higher than the temperature normally required to dip into the second plastisol.

Claim 29

The dip molding process of claim 25 comprising dipping said mold into said second plastisol approximately 30 to 90 seconds after said mold leaves said first plastisol.

Claim 30

The dip molding process of claim 25 comprising: dipping said mold into said second plastisol in approximately one minute of the time said mold leaves said first plastisol.

Claim 31

The process of claim 27 in which said mold is maintained in an atmosphere cooler than the temperature of said mold during said delaying step whereby the surface of the first coating of plastisol on said mold has an opportunity to cool somewhat prior to initiation of said subsequent dip.

Claim 32

The dip molding process of claim 28 comprising: dipping said mold onto said second plastisol sufficiently soon after it leaves said first plastisol that the temperature of said mold drops only approximately 30* F. from the time at which it is first dipped into said first plastisol and the time that it is first dipped into said second plastisol.

Claim 33

The process of claim 24 comprising maintaining said mold in an atmosphere cooler than the temperature of said mold following completion of the first dip into said first plastisol during said delaying step.

Claim 34

The process of claim 24 comprising: providing at least said first plastisol of a composition which gels to a roughened surface shortly after dipping is completed.

Claim 35

The process of claim 24 comprising: providing at least said first plastisol of a mixture of first resin particles having an average particle size of less than 500 microns, a similar resin having particles whose size with relationship to said first resin particles is in the range of approximately 6.5 to 1 to 200 to 1, and a suitable plasticizer.

Claim 36

The process of claim 32 in which said second plastisol is the same as said first plastisol.