U.S. patent number 3,861,955 [Application Number 05/016,192] was granted by the patent office on 1975-01-21 for decorating method.
Invention is credited to James H. Lemelson.
United States Patent |
3,861,955 |
Lemelson |
January 21, 1975 |
DECORATING METHOD
Abstract
A method for decorating articles of manufacture as or
immediately after they are formed. Particulate decorating material
is applied to selected areas of the article either directly or
indirectly and is fused in situ on the article.
Inventors: |
Lemelson; James H. (Metuchen,
NJ) |
Family
ID: |
26688291 |
Appl.
No.: |
05/016,192 |
Filed: |
March 3, 1970 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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421897 |
Dec 29, 1964 |
3504063 |
|
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Current U.S.
Class: |
427/131; 428/206;
101/12; 101/17; 101/129 |
Current CPC
Class: |
B29C
45/14778 (20130101); B29C 49/22 (20130101); B23K
15/002 (20130101); B29C 37/0032 (20130101); B29D
22/04 (20130101); B29C 41/08 (20130101); B29C
2791/001 (20130101); B29K 2101/12 (20130101); B29K
2709/08 (20130101); B29C 2035/0877 (20130101); B29K
2709/02 (20130101); B29K 2995/002 (20130101); B29K
2069/00 (20130101); Y10T 428/24893 (20150115); B29K
2105/16 (20130101); B29K 2063/00 (20130101); B29C
49/04 (20130101); B29L 2031/7158 (20130101); B29L
2031/722 (20130101); B29K 2077/00 (20130101); B29C
2037/0039 (20130101); B29C 2035/0838 (20130101); B29C
67/04 (20130101); B29C 2049/026 (20130101); B29C
2049/027 (20130101); B29C 2795/002 (20130101); B29K
2023/06 (20130101); B29K 2707/04 (20130101); B29K
2995/0087 (20130101); B29K 2705/00 (20130101); B29K
2101/10 (20130101) |
Current International
Class: |
B29C
41/08 (20060101); B29C 37/00 (20060101); B29C
45/14 (20060101); B29D 22/04 (20060101); B29D
22/00 (20060101); B23K 15/00 (20060101); B29C
67/04 (20060101); B29C 67/02 (20060101); B29C
35/08 (20060101); H01f 010/00 () |
Field of
Search: |
;117/5.5,9,17,17.5,19,21,25,38,93.31,93.4,235,17.5,238
;118/301,624 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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251,780 |
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May 1963 |
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AU |
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660,755 |
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Mar 1865 |
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BE |
|
Primary Examiner: Martin; William D.
Assistant Examiner: Pianalto; Bernard D.
Parent Case Text
RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 421,897
filed Dec. 29, 1964, now U.S. Pat. No. 3,504,063, for Article
Decoration Apparatus and Method.
Claims
I claim:
1. A method of selectively coating a thermoplastic material onto a
substrate comprising:
disposing a multitude of heat fusible particles of paramagnetic
thermoplastic material onto the surface of a substrate as a
substantially uniform layer covering a first area of said surface,
and magnetically retaining said particles against said first area
of said surface, and
while said particles are magnetically held against said first area
of said surface by magnetic force, subjecting selected of said
particles covering a first portion of said first area of said
substrate to heat generating radiation of sufficient intensity to
melt and fuse said particles to said first area of said substrate,
solidifying the melted particles as a layer against the surface of
said substrate and
removing those particles disposed against the remaining portion of
said first area of said substrate which have not been caused to
melt and fuse to said substrate by said radiation whereby said
first portion of said first area of said substate is coated with
said paramagnetic material.
2. A method in accordance with claim 1 wherein said first portion
of said first area of said substrate is at least partially inclined
to the horizontal and the magnetic retention of particles thereon
is operable to hold the particles against the inclined surface
during the heating and melting operations.
Description
SUMMARY OF THE INVENTION
An apparatus and method are provided for decorating and selectively
depositing material onto surfaces of articles or sheet-like
substrates. The decorating material is provided in a fluent state
and is transferred either directly to the surface of the article, a
parison from which the article is to be made or a mold surface
against which the article is to be shaped.
Most conventional article decorating techniques involve the direct
transfer of decorating material through a mask or from a printing
device to the surface to be decorated. The former requires the
constant cleaning of masks while printing is limited to the
decoration of relatively smooth surfaces. If made automatic both
printing and spray decorating require relatively complex article
handling and prepositioning apparatus to dispose the articles in
alignment with the spray mask and spray heads. Silk screening
equipment for decorating shaped articles is limited primarily to
the decoration of flat or smoothly contoured articles and requires
the cleaning, inspection and constant replacement of screens. Such
procedure also requires that the articles be properly prepositioned
and aligned with the screen printer necessitating complex and
costly conveyors and positioning equipment to align articles.
Automatic screening equipment may not be easily changed or altered
to accompodate differently shaped articles and hense, is generally
used only for the decoration of bottles and the like of regular
shape requiring large production runs. Odd shaped articles are not
easily decorated by screen or spray means operative to apply liquid
decorating inks, enamels or plastics.
Accordingly, it is a primary object of this invention to provide a
new and improved apparatus and method for molding, and decorating
articles of manufacture.
Another object is to provide an apparatus and method for shaping
articles of manufacture in a mold or die and decorating said
articles during the shaping operation so as to eliminate the need
to rehandle the article thereafter in the act of decorating
same.
Another object is to provide a new and improved apparatus for
forming composite articles by selectively depositing a first
material in a mold and molding a second material in situ against
said first material so as to form an integral molding therewith
made of both materials.
Another object is to provide an improved apparatus for coating
selective areas of the walls of a mold cavity with material,
operative to become part of an article formed to shape in said
mold.
Another object is to provide an apparatus for selectively
depositing surface coating material on a mold wall by electrostatic
means.
Another object is to provide an improved electrostatic surface
decorating apparatus including means for rapidly charging a
photo-conducting surface, means for selectively discharging areas
of said surface and means for disposing particulate surface
decorating material onto selected charged areas of said material,
all operative simultaneously or in rapid sequential succession.
Another object is to provide means for forming molded articles with
portions of the surface thereof defined by abrasive particles.
Another object is to provide improved structures in molds and mold
inserts applicable for decorating articles,
Another object is to provide new and improved structures in molds
operative to receive plural materials.
Another object is to provide improved structures in printing
plates, masks and methods for utilizing same to decorate irregular
surfaces therewith.
Another object is to provide a new printing method applicable for
decorating irregular surfaces.
Another object is to provide an improved method and apparatus for
coating molds with substantially the required quantity of mold
release material and maintaining said condition throughout many
molding cycles.
Another object is to provide apparatus and methods for selectively
coating various articles formed in dies such as stampings and
forgings by coating the walls of said dies prior to engagement with
said articles.
Another object is to provide an apparatus and method for
selectively coating surfaces of articles formed from sheet material
during the process of stamping or pressure deforming sheet material
to form said articles.
Another object is to provide improved means for spraying decorative
and surface conditioning materials through a mask in a manner
whereby a minimum amount of spraying material is deposited on the
mask.
Another object is to provide apparatus and methods for selectively
coating or decorating articles wherein magnetic forces are employed
to effect same.
Another object is to provide a method of decorating and printing by
selectively depositing thermoplastic particles on to predetermined
areas of a surface, rendering same semi-molten thereon and
transferring the semimolten indicia to another surface to which it
becomes bonded upon solidifying.
With the above and such other objects in view as may hereafter more
fully appear, the invention consists of the novel constructions,
combinations and arrangements of parts as will be more fully
described and illustrated in the accompanying drawings, but it is
to be understood that changes, variations and modifications may be
resorted to which fall within the scope of the invention as
claimed.
In the drawings:
FIG. 1 is a side cross-sectional view of a portion of a molding
apparatus including a mold member having a cavity in which material
is molded to shape and auxiliary apparatus operative to deposit a
material onto selected areas of the wall of the mold cavity which
material coats or eventually defines a portion of the article
molded therein;
FIG. 2 is a side cross-sectional view of the apparatus in FIG. 1 in
operative relationship in the act of selectively coating the mold
wall;
FIG. 3 is a side cross-sectional view of the mold member of FIG. 1
assembled with a second mold member to define a molding cavity
after processing the wall of the mold cavity by the means
illustrated in FIGS. 1 and 2;
FIG. 4 is a side cross-sectional view of an article molded in the
apparatus of FIG. 3;
FIG. 5 is a front view of the article of FIG. 4;
FIG. 6 is a side cross-sectional view of a modified form of the
apparatus of FIG. 1 in which coating material is transferred to the
wall of the mold cavity by means operative to preposition and
engage the surface of the mold cavity;
FIG. 7 is a side view of a modified type of mold coating
apparatus;
FIG. 8 is an end view showing further details of apparatus for
selectively coating areas of a mold cavity wall;
FIG. 9 is an end view of a modified form of apparatus of the type
illustrated in FIG. 8;
FIG. 10 is a side cross-sectional view of a molding apparatus and
an apparatus operative to electrostatically charge the surface of
the wall of the cavity of a mold;
FIG. 11 is a side cross-sectional view of apparatus operative to
selectively discharge areas of the surface of the cavity wall of
the mold of FIG. 1;
FIG. 12 is a side view of the mold of FIG. 11 and a further
apparatus for depositing particulate or droplet material against
selected areas of the wall as defined by the means of FIGS. 10 and
11;
FIG. 13 is an end view of an apparatus for prepositioning the
surface charging, discharging and depositing means of FIGS. 10 to
12;
FIG. 14 is a side view of a modified form of apparatus operative to
perform similar to that provided in FIGS. 10 to 12.
FIG. 15 is an end view in cross section of a fragment of a die
applicable for decorating or welding articles of manufacture
and
FIG. 16 is an end view in cross section of a modified form of fluid
heated die applicable for decorating or welding articles of
manufacture.
This invention is concerned with molding articles having composite
surface structures produced by selectively depositing one or more
materials against a predetermined area or areas of the surface of
the wall of a mold cavity which is shaped to define the shape of
the article molded therein. After such selective deposition, which
is preferably effected by electrostatic means, molding material is
injected, poured, compressed, blown or otherwise caused to enter
the mold cavity and abut the wall thereof and combine with the
deposited material which becomes an integral part of the material
being molded, preferably defining at least a portion of the surface
of the article molded in the cavity. While the apparatus and method
are primarily intended for use with polymeric materials such as
thermoplastic resins, other materials may also be utilized as the
molding and decorating materials such as metals, ceramics, glass,
non-metallics or the like in combination with each other or said
polymeric materials.
Molding techniques applicable to this invention in addition to
injection molding which will be described, include compression
molding, slush or rotational molding, pour molding, compacting such
as prior to sintering, spray molding and the like.
The process involves the steps of (a) selectively depositing a
first material in the form of fine droplets or particulate solid
material onto selected and predetermined areas of the surface of
the wall of a mold cavity; (b) molding a material in said cavity
which material is in such a state prior to or during molding by
virtue of its molten or semi-molten condition that it forms an
integral bond with the first material deposited on the surface of
the mold cavity wall. Depending on the materials employed and the
molding procedure, the first material may, prior to introducing the
molding material thereagainst, remain in the state, liquid or
powder, in which it is initially deposited or may be further
processed prior to molding thereagainst. For example, if said first
material is a thermoplastic applied in particulate or powder form,
heat applied through the mold wall or by radiant or other means may
be utilized to cause the particles to melt into a unitary mass
prior to molding. Such mass or coating may remain semi-molten
during molding or may be cause to solidify just prior to molding
depending on the materials employed and the parameters of the
molding procedure.
In a preferred form of the invention, both the molding and
decorating materials comprise thermoplastic resins such as
polyethylene, polypropylene, polyamide, polyvinyl-chloride,
acetate, styrene or the like with the decorating material
selectively applied to predetermined areas of the mold wall by
spraying or dusting with charged powder particles of the same or
different resins which are attracted to areas of the mold wall
which areas have been rendered of opposite electrostatic charge to
that of the particles. The procedure is continued for a
predetermined time interval until a desired amount of material has
been deposited or desired thickness of coating has formed, after
which the molding material is introduced against the surface of the
mold cavity wall and caused to combine with the applied material by
fusion therewith.
Other materials which may be applied to the selected areas of the
surface of the mold include powdered metal, ceramic, glass,
thermosetting resins, carbon, etc. or any of these materials in
other forms such as droplets, fibers, chips or the like which may
be selectively deposited by electrostatic means. The molding
materials may be molten, semi-molten, powder or other forms of the
above materials which are poured, injected, compacted, blown or
otherwise introduced into the mold cavity. A predetermined quantity
of the same or different materials may be flowed by gravity, dusted
or brush applied, inertially projected, carried on a stream of
another fluid such as air or otherwise dispensed to flow against
the wall of the mold cavity and caused to deposite onto selected
areas thereof by electrostatic or magnetic attraction means or
masking means. If carried on an air stream or other fluid dispensed
from a nozzle, they may be charged or magnetized in the gun or
nozzle from which they are ejected against the mold wall for the
selective deposition thereof as will be hereinafter described. They
may also be rendered molten or semi-molten in the nozzle or gun to
provide same as a continuous coating on the said selected area or
areas of the mold wall which wall may be cooled by heat transfer
fluid flowing therethrough to rapidly solidify the coating material
and the molding material disposed thereagainst thereafter.
The process may also be applicable to the selective coating or
decorating of articles which are stamped or otherwise formed in a
die or pressure forming mold oeperative to form sheet material if
the coating material is either provided in a molten state when
applied or rendered molten or semi-molten in the die just prior to
forming a sheet therein.
The process and apparatus described hereafter may also be utilized
for selectively coating or plating the wall of molds and other
irregularly shaped articles with materials operative to improve the
operation thereof, or in cetain instances such as the fabrication
of electrical circuits or electrical devices, to provide insulating
and/or conducting portions thereof.
There is shown in FIG. 1 an apparatus 10 including a mold or die
member 11 and an assembly 18 which is operative to apply material
to selected areas of the surface 13 of the wall 12 of a mold cavity
12' defined at least in part by mold member 11. Member 11 may be
utilized per se or in combination with one or more further mold or
die members operative to shape a material by casting, injecting or
otherwise disposing said material in the mold cavity against the
surface 13. Prior to disposing said material against surface 13, in
accordance with the teachings of this invention, one or more
selected areas of the cavity wall are coated or otherwise covered
with a material which will eventually define a portion of the
surface of the article shaped in the cavity 12'.
Assembly 18 includes an elongated support member 26 which is
secured to a frame or flanged retainer 23 having a mask 19 which is
shaped to conform to at least part of the surface 13 of the wall 12
of the cavity 12' in member 11 and has a plurality of openings 22
in a shell-like portion 21 thereof extending from a flange 20
secured to the flange of member 23. In other words, members 19 and
23 define a hollow enclosure having a wall portion operative to
engage and serve as a mask for the surface 13 upon being moved
thereagainst or abutted by movement of member 11.
Centrally disposed within frame or housing member 23 is a nozzle
assembly 24 having a tip 25 with one or more openings 25' therein
from which streams of material in particulate, droplet or atomized
form may be directed through the opening 22 in wall 21 of the mask
19 to be disposed against surface 13. Such material may be fed
under pressure per se or on a carrier stream of fluid such as air
through a tube or conduit 24' held by support member 26 to the
nozzle 24 upon alignment of assembly 18 with 11 and engagement of
the outer surface of the mask 19 with the proper portion of the
surface 13 of mold 11.
The mold wall deposition apparatus of FIG. 1 is subject to a number
of variations in structure and mode of operation. In its simplest
form, the shell-like mask or stencil 21 may be molded of sheet
material with its outer surface adapted to conform to the shape of
the wall 13 of the mold cavity 12' in the face or wall 12 of the
mold. Upon engagement of the outer surface of mask 19 and the
surface of wall 13, material may be directed as one or more streams
of powder or atomized liquid through the opening or openings in the
mask and become disposed in the shape of the opening against a
predetermined area of the cavity wall. After a predetermined
quantity of such material has been so deposited, automatic control
means such as a cycle controller may be operative to terminate the
flow of such material by closing a valve or deenergizing a pumping
means after which said control means is operative to effect
retraction of the mask and spray assembly from the mold cavity
and/or movement of the mold member 11 to separate the two so that
molding may be effected thereafter. With such an arrangement, it
will be necessary to wipe or otherwise remove sprayed material from
the mask 19 periodically if not during each cycle so as to prevent
such material from running along the outside surface 21 of the mask
and become deposited on the mold cavity wall 13 and to prevent
clogging of the openings 22 in the mask. Such cleaning operation
may be effected by automatic means such as operative to imerse it
in a solvent while molding is in progress.
Electrostatic forces may be employed in order to reduce
contamination of the mask and assure that a larger percentage of
the sprayed material is actually deposited on the selected area or
areas of the mold cavity wall surface. A number of techniques may
be employed as hereinafter presented. In a first method, the mold
or an insulated liner therefore defining the wall of the cavity 12'
as hereinafter provided, may be electrically charged to a first
polarity and the sprayed particulate material or atomized droplets
charged in the gun to a the same polarity. If the mask 19 is
uncharged and non-conducting or insulating to the charge on the
surface of the mold cavity wall, the finely devided spray particles
are only affected by and attracted to the surface or surfaces of
the mold cavity wall exposed through the openings in the mask. Thus
substantially all of the particles will flow through the mask or
stencil openings and deposit on the mold wall surfaces exposed
therethrough. The spray nozzle 24 and its related feed and charging
apparatus may comprise apparatus manufactured by Shames,
Incorporated of Palisades Park, New Jersey under the trade name,
Stajet which is defined as electrostatic dry powder spraying. If
thermoplastic powder is so deposited, it may be melted to form a
contiguous coating on the surface area or areas defined by the
openings 22 in the mask by heat applied to the mold wall from
either the previous charge molded therein or by means of heat
transfer fluid flowed through passageways 15' in the mold wall
adjacent the surfce 13 of the cavity. A high voltage, low amperage
charge on such particles is applied in the nozzle being of the
order of 100 KV potential and continuous flow is effected until
terminated under mild air pressure of 0.3 to 1.5 pounds per square
inch.
In a second method, the mask 19 or a coating thereon, may be
charged to a potential opposite to that at which the particles or
droplets are charged so as to effect repulsion of said particles
therefrom and effect their direction through the openings 22
therein. If sprays of particulate material are directed in the
general vicinity of the openings 22 in the mask and are controlled
in their flow path as well as duration, then those particles which
would ordinarily impinge on the uncharged mask, will be repelled
therefrom and directed through the openings therein. Variations in
this method include constructing the mask with conductive coatings
or metal members which are selectively positioned around or
adjacent to the openings in the mask and are adapted to be
electrically charged to repel oppositely charged particles or
droplets therefrom so as to permit flow of said particles through
the mask openings and deposition thereof onto the areas of the mold
cavity wall exposed through said openings. Connection of the mask
conductors or coatings with a source of the proper potential may be
effected through wires extending along the support 26 to the source
of potential through a control or switch which is operative by the
same electrical control means controlling the other molding
variables. While it may not be necessary to charge the mold member
11 to attract sprayed particles thereto through the mask openings,
such means may be operative to improve the selective mold coating
operation.
In a third method, a fine electro-conductive metal screen is
disposed in the mask openings 22 and is charged so as to charge the
particulate material flowed therethrough from the spray gun or
other means. The mold or cavity wall liner therefore is oppositely
charged so as to attract the particles passing through the screen.
The particles are thereafter fixed or melted and solidified as
described prior to the admission of the molding material to the
mold. The entire stencil 19 may be made of such electro-conductive
metal screen which is shaped to the contour of the mold cavity wall
and is internally supported and secured to member 18. Disposing a
shell or non-conductive coating along the inside surface of the
screen mask along those areas aligned with portions of the mold
cavity wall which are not to receive coating material will serve to
render the screen a stencil-like structure in which non-coated or
covered areas thereof define openings through which particulate
material may flow to the surface of the mold cavity wall.
In mask constructions involving such a fine, electro-conductive
metal screen, the screen may be embedded within the wall of the
stencil or mask 19 or bonded to the front or rear surface thereof.
If bonded to the front surface of 19, the mask may be positioned
away from the surface of the mold wall so as to prevent shorting.
If supported within or behind the the mask base 19, the screen will
be insulated thereby from the mold wall and if 19 is
non-conducting, its front face may engage the face of the charged
mold cavity wall or a liner therefore.
Electrostatic atomizing equipment applicable to the mold coating
apparatus of FIG. 1 may comprise a centrifugal atomizer such as the
model FR manufactured by Ionic Electrostatic Corporation of
Garfield, N.J.
Particulate solid materials may be applied to the surface of the
mold cavity wall by means other than spraying such as gravity flow
or brush means disposed adjacent the mask or within the assembly 18
and operative to provide a steady flow of particles against the
mold wall through openings in the mask or against selecteively
charged portions of the mold wall adapted to electrically retain
particles against the areas so charged. means as described
hereafter such as photoconductive mold coating means may be
employed to selectively charge predetermined areas of the mold wall
to retain opposite charged particles thereagainst. Or the mold wall
may be constructed with portions thereof which define the surface
of the cavity 12' being chargeable while adjacent portions are not
so chargeable for attracting sprayed or otherwise flowed particles
of coating material when electrically energized or charged.
FIG. 2 illustrates assembly 18 in working relationship with member
11 whereby material may be sprayed from nozzle 24 through the
openings 22 in mask member 19 so as to coat selected areas of 13.
Such positioning is preferably effected after the mold 11 has been
conditioned and positioned for the coating operation by the
controlled movement of either or both member 11 and assembly 23.
Upon attaining the mating relationship between the assembly and
mold member 11 as illustrated in FIG. 2, a predetermined quantity
of material is flowed through the inlet to the nozzle 24 and is
ejected through one or more holes in the nozzle tip portion 25
through the opening or openings in the mask until a coating or
covering of predetermined depth has been applied to the surface of
the mold.
In FIG. 3, the assembly 24 has been removed from the vicinity of
the mold member 11 and a second mold member 16 is shown assembled
with 11 to define a molding cavity 17 into which molding material
such as a polymer, ceramic or metal may be flowed through an
opening or inlet 15 shown in mold member 16. Notation 27 refers to
the material disposed against the surface 13 of mold member 11 by
the means described which defines a portion of the outer surface of
the molded member 28 shown in FIG. 4. Depending on the
characteristics of both the molding material and the material 27
applied to portions of the surface 13, retention of said material
against the molded article may be effected by mechanical means
resulting from molding in situ thereagainst or bonding or welding
means resulting from fusion of the molding material and the spray
applied material 27.
Other features of the apparatus illustrated in FIGS. 1-3 include
the provision of a plurality of passageways 15' in the mold section
11 through which heat transfer material may be flowed to perform
one or more of a plurality of functions. For example, if the
material ejected from nozzle 24 and directed through the openings
22 of the mask 19 is a particulate thermoplastic polymer, it may be
desirable to melt said material in situ on the surface of the mold
and solidify same into one or more formations which are temporarily
bonded to the mold wall until molding occurs whereafter they also
become bonded to the molding material and are removable therewith
upon removal of the molded article from the mold. In such an
arrangement, if the material is not sprayed from the nozzle in a
molten or semi-molten condition, it may be desirable to pass a hot
fluid or liquid through the passageways 15 to heat the wall of the
mold to cause the melting of the applied particulate material. Such
heating may also be desirable to cure a thermosetting resin applied
in particulate or droplet form to the surface 13 through the
openings in the mask prior to molding. In order to hasten
solidification of the molding material in the mold cavity, it may
also be desirable to pass a coolant or heat transfer fluid through
passageways 15 disposed adjacent to cavity and operative to rapidly
remove heat from the mold wall. Or, if a thermosetting resin is
applied in particulate or fluid state to the mold cavity during
molding, it will be desirable to heat the wall of the mold to cause
same to set by passing a heated fluid through the passageways 15 in
the mold wall. Although not illustrated, the mold member 16 of FIG.
3 may also contain heat transfer fluid passageways connected as are
the passageways 15 of mold member 11 to a source of heat transfer
fluid through a control means therefor such as a valve which may be
cyclically controlled by means of interlock switches or a
programming means operative to control the other molding variables
which have been described or will be described hereafter.
In another form of the invention, if mold member 11 is metal, the
mask 19 may be insulated therefrom by a coating of insulating
material disposed against the outer surface of portion 21 thereof
while the remainder of the mask may be made of metal which is
charged to a first potential. If the nozzle 24 contains means for
charging the material ejected therefrom to a polarity which is
similar to that charing the mask, then the streams of particulate
or droplet material will be repelled from the mask but will be
allowed to pass through the openings therein so that the mask
itself will not be come interiorly coated and substantially all of
the coating material will become disposed against the selected
areas of the wall of the mold defined by the openings in the mask.
A suitable mask design may comprise one in which metal sheet which
charge to the polarity of the coating material is disposed behind
the face of a mask shell made of insulating material and is so
contoured as to provide the proper flow of coating material when
charged to a predetermined potential. Generally, it is desirable to
charge the mask to a potential of from 100 to 800 volts either
positive or negative polarity with a similar polarity rendered on
the particles or droplets sprayed from nozzle 24 by passing same
between electrodes or over a drum of higher potential charge.
If the material ejected from nozzle 24 is in particulate form, it
may remain so just prior to molding and even after molding
depending on the composition of the composite article to be
produced. Particles of ceramic or metal may be made part of the
molded article by mechanical retention thereagainst when the
molding material encapsulates at least a portion, if not all, of
said particles or may melt upon flowing the molding material into
the cavity by means of heat transferred thereto from said molding
material. Furthermore, it is noted that the mold member 11 may have
retained sufficient heat from the prior molding cycle to melt and
fuse the particulate or droplet material disposed thereagainst as
described so as to form one or more solid or semi-molten coatings
on the surface of the mold.
FIGS. 4 and 5 illustrate the molded article 28 containing selected
areas 27' thereof coated or inlayed with coating material as
described which may be used for decorative or other purposes. If
the molding material is a thermoplastic polymer of a first color,
the material applied to the wall of the mold may comprise the same
or a different polymer of a second color operative to decorate
same. The material applied to the wall of the mold through the mask
may serve other functions then merely to decorate the surface of
the molded article. For example, it may be made of a polymer or
other material having a higher or lower lustre, frictional
characteristic, rigidity, strength, lubricity or other
characteristic than the molding material. For example, conducting,
non-conducting and semi-conducting materials may be applied to
surfaces of molded articles by the means described as may
electrical circuit components and the like.
The apparatus of FIGS. 1 and 2 may also be operative for forming
articles of manufacture with surface decorations by means other
than molding. For example, member 11 may comprise part of a
stamping die assembly operative to receive sheet or other material
which is deformed into the cavity 12 and is compressed against the
material coated thereagainst as described whereby, when the
stamping is removed from the cavities, said decorative or coating
material will be retained against the die-stamped article. Such
retention may be effected by providing the deformed sheet of a
material having a greater affinity for the material coated against
the wall 13 than the material comprising said wall or by heating,
coating or otherwise processing the sheet material so as to retain
the material temporarily retained against surface 13.
Regardless of the process utilized to form the composite article,
for certain coating and molding materials it may be desirable to
provide the surface 13 of the mold cavity 12' of a material which
will release the coating material 27 to the article formed
thereagainst and said surface may be part of a coating or liner
disposed against the mold such as polytetrafluoroethylene or the
like. The surface 13 may also have a lubricant applied thereto
prior to application of the coating material 27. Such lubricants as
graphite film, silicone materials and the like may be automatically
sprayed, applied by glow discharge means or other means against the
surface of the mold cavity prior to applying material 27
thereagainst. The electrical glow discharge electrode as well as
means for expelling the desired vapor to be deposited against the
mold wall may be mounted within the housing defined by notation 24
or insulatedly supported off housing member 18. A monomer
discharged as a vapor from the spray nozzle 24 may be directed as
described against predetermined areas of the mold wall and
polymerized in situ thereon by the action of the glow discharge
means. The glow discharge means may also include an electrode
defined by mask member 21 or secured thereto and of such a
potential as to polymerize the monomer vapors or particles
deposited on the mold wall as or shortly after deposition.
In the hereinbefore described molding and decorating procedures,
one or more articles may be secured to the surface of the mold
cavity wall prior to or after application of the spray deposited
coating material to form composite articles made of the molding
material, the deposited material and said secured articles.
Accordingly deposition as described may be effected on either or
both the articles and the mold wall prior to molding.
FIG. 6 illustrates the molding apparatus of FIG. 1 having
decoration means 30 therefor operative to provide material against
the surface 13 of the mold cavity wall for the purposes described
by means of transfer of said material from a form 31 having its
outer surface 32 conforming to the mold wall when in operative
relation therewith. The form or transfer device 31 is supported by
an arm or frame 33 which is movable from a position in which it
clears the mold sections so as to permit closure of the mold to a
position directly in line with mold cavity 12 after which either
the mold member 11 moves to engage or move closely adjacent the
surface 32 of 31 or the means supporting 33 is operative to move
the printing form into engagement with the surface of the mold
cavity so as to effect transfer of one or more coatings or articles
27" disposed against surface 32. The material 27" may be attracted
to surface 13 upon engagement therewith as a result of the partial
or complete transfer of said material by adhesion thereagainst. If
the material 27" and/or the mold member 11 are provided with an
electrical charge or charges operative to attract and retain said
material against the surface of the mold cavity wall, then such
means may be provided to effect transfer of all or part of said
material. The apparatus of FIG. 6 preferably includes automatic
means for replenishing the one or more coatings or articles 27" to
be transferred from the surface 32 to the mold wall while the mold
is being utilized for molding purposes and such operation is
preferably completed prior to completion of the molding operation
so that the transfer member 31 may be immediately projected or
rotated into position in alignment with the mold cavity. The
material 27" disposed against the face 32 of transfer form 31 may
comprise preshaped inserts of metal, plastic or ceramic fed into
position and bonded or otherwise retained against surface 32 by
automatic assembly means. It may also comprise coating material
sprayed, screened, roller or otherwise disposed against selected
areas of surface 32 by automatic means operative during the molding
cycle and preferably controlled by a single programming means which
also controls the other molding variables so as to synchronize the
molding and decoration operations.
FIG. 7 illustrates a modified form of the invention which includes
a support 33 for a form 34, the outer surface of which is shaped to
substantially conform to the surface 13 of the mold cavity wall.
Disposed against the outer surface 34' of 34 is a sheet 35 of
decorative material such as printed flexible plastic film or
thermally deformed rigid plastic sheet. Either or both surfaces of
the sheet or film 35 are preferably decorated by printing which
decorative printing becomes part of the molded article when 35 is
disposed against the surface 13 of the mold cavity by movement of
either the mold or the assembly supporting 35 to cause engagement
of 35 against the mold cavity wall. Securing of member 35 to the
mold cavity wall may be effected by bonding thereagainst resulting
from temporarily heat sealing 35 thereto or by electrostatic means
in which either or both the mold and film 35 are statically charged
so as to effect attraction and retention of 35 against the cavity
wall upon engagement therewith permitting removal of the form 34
from the vicinity of the mold cavity and its retraction so as to
clear the mold to permit the closure thereof and effect a molding
cycle in which material is molded directly against sheet 35
disposed against the surface of the mold cavity wall.
Apparatus associated with the transfer means illustrated in FIG. 7
preferably includes means for automatically disposing new sheet
material 35 against the outer surface of form 34 while the molding
operation is in progress, such means preferably being automatic.
This may include means for prepositioning thin, preprinted or
otherwise decorated film over the form 34, draping and retaining
same thereagainst by bonding or electrostatic means. If
electrostatic means is utilized to retain decorated plastic film
against surface 34', it is preferably of a lower order of
attraction then the charge disposed along the surface of the cavity
of mold 11 so that the film will transfer thereto without
difficulty.
In another form of the invention illustrated in FIG. 7, a printed
or otherwise decorated sheet of thermally deformable plastic film
is either shaped to the contour of surface 34' by conventional
vacuum or pressure forming means or is thermally deformed in situ
thereagainst while molding occurs.
In still another form of the invention, means may be provided for
clampingly engaging a sheet of decorated, thermally deformable
plastic against the face 14 of mold member 11, heating said sheet
to a semi-molten condition and applying pressure to the outer
surface thereof or a die to cause same to enter the cavity and to
conform to the surface 13 of the cavity wall. By die cutting said
sheet against either surface 13 or 14 and retaining it in position
against surface 13, it may be utilized to form an integral portion
of the article shaped when molding material is injected into a mold
cavity thereafter and solidified in situ thereagainst.
Notation 33' in FIG. 7 refers to an air line extending through
member 33 to an opening therein extending to the interior of shell
or from 34. One or more holes 34' in member 24 permit pressurizing
the internal volume 34" to cause sheet 35 to be forced off shell
34. If vacuum is applied to volume 34 through line 33' it may be
used to vacuum form the decorated thermoplastic sheet in situ
against the surface of shell 34 to conform thereto so that sheet 35
will conform to the shape of the mold cavity wall.
In other words, the apparatus of FIG. 7 may be operative in a
plurality of modes to provide a form or sheet of decorative
material against the surface of the mold wall cavity to become an
integral part of the article molded thereafter in the mold. In a
first mode of operation, a sheet 35 of preshaped decorative
material such as printed or otherwise decorated transparent,
translucent or colored plastic having decorations provided on its
outer surface 35', is prepositioned on the form 35 while the form
is retracted from the mold and preferably during the previous cycle
of molding and is held thereagainst by suction applied through line
33'. After the mold has been opened and the previously molded
article removed therefrom, member 33 is automatically moved to
position sheet 35 against the surface of the mold cavity wall.
Positive air pressure and/or electro-static forces are thereafter
used to remove member 35 from the surface of shell 34 and retain it
against the surface of the mold cavity wall. Pressure applied
through line 33' or the release of vacuum therefrom with sheet
member 35 and/or the mold itself being electrostatically charged,
may be utilized to secure sheet 35 to the mold wall.
In a second mode of operation, a decorated sheet of plastic or
other material such as metal, is deformed against the outer surface
35' of shell 35 by vacuum, pressure or die means and made to
conform thereto while the shell is retracted from the mold and
during the molding part of the cycle. Thereafter the shell 34 is
positioned in alignment with the mold cavity and projected therein
so as to engage sheet 35 against the irregularly shaped wall of the
mold cavity. Transfer and retention of the deformed sheet to
conform to the surface of the mold cavity wall is next effected as
described.
FIG. 8 illustrates part of a molding apparatus including mold wall
decoration means of the type described which is pivotally movable
into alignment with the cavity of a mold section 11 of a multiple
part mold, the other part of which is not illustrated but is
closeable against the face of part 11 when the surface decorating
means illustrated has cleared the side of the mold.
The mold section 11 is shown movable longitudinally along a
plurality of parallel cylindrical guide rods 36 which are supported
on a frame secured to the mount 37 for the molding apparatus. The
lineal actuator such as a hydraulic cylinder (not shown) is
connected to mold section 11 and moves same longitudinally along
rods 36 in the act of opening and closing said mold section
against, for example, mold section 16 shown in FIG. 3 for defining
a molding cavity therewith. When retracted therefrom, the front
face of mold section 11 clears a positioning device for the mold
mask 19 or the apparatus of FIGS. 6 or 7 which is mounted on an arm
26 which is pivotally supported for rotation with a shaft 44 of an
actuating device 43 shown mounted on the floor at the side of the
mold base 37. Actuator device 43 may be of any suitable design and
is operative to either locate the mask 19 and mount 23 for the
spray nozzle from the position illustrated in FIG. 8 to a position
directly in alignment with the mold cavity 12 so that either
further movement of said mask as the result of lineal movement of
shaft 44 and/or movement of the mold section 11 will bring the face
of the mask into surface abutment with the surface 13 of the mold
cavity. Notation 39 refers to a pipe or conduit extending along
support 26 and connecting the spray nozzle 24 with means for
pressurizing material to be sprayed through the openings in the
mask. A section 40 of conduit 39 is flexible and connects the lower
end of 39 with the output of a pump 41 disposed between a reservoir
42 containing material to be dispensed through nozzle 24. Operation
of the apparatus of FIG. 8 is preferably automatic and synchronized
so as to position the mask in alignment with the mold cavity, move
the mold member 11 and/or shaft 44 to bring the two surfaces into
abutment with each other, operate the pump 41 or a valve in such a
manner as to dispense a predetermined quantity of coating material
through the spray nozzle; flow heat transfer fluid through the
passageways in the mold to affect material deposited on the surface
of the mold cavity wall; retract the mold and/or mount for the mask
and pivot the latter so as to clear the mold; move the mold member
11 so as to close against the other mold member to define a molding
cavity; inject a predetermined quantity of molding material into
the mold; cause flow of further heat transfer fluid to effect
solidification of the molding material; opening the mold after said
solidification and effect removal of the molded composite article
from that portion of the mold against which it is retained prior to
withdrawal or knockout. Such a cycle of operations may involve
program control of various servo motors and valves under the
control of a single, variable programming device such as a
multicircuit timer.
FIG. 9 illustrates further modifications to the apparatus
hereinbefore described which includes a lineal actuator 45 disposed
on a mount 37' extending from the side of the mold frame or base 37
and operative to project a shaft 46 mounting the mask 19 or the
devices of FIGS. 6 and 7 into alignment with the mold cavity 12.
Thereafter, the servo means moving mold 11 is operated to bring the
mold cavity into abutment with the aligned mask 19 and material is
transferred from the dispensing device as described. In FIG. 9, the
dispensing device includes a nozzle or other form of particulate or
droplet forming and dispensing means 50 which is shown pivotally
mounted in a yoke 47 and is pivoted therein by means of a small
servo motor 49 secured to shaft 46 so as to permit directing of
material ejected therefrom along one or more predetermined paths
within the volume defined by the mask 19. Device 50 is supported on
a shaft 48 which is rotatable in the yoke 47 and servo device 49 is
preferably program controlled in its operation for certain mold
decorating applications. However, in many applications, it may
suffice to provide the design of the nozzle head or tip 25 with one
or more openings therein which are so positioned as to direct one
or a plurality of streams of liquid, particulate or droplet
material along substantially predetermined paths so as to pass
through the openings in the mask 19. Notation 40 refers to a
flexible conduit of sufficient length to connect the nozzle 50 with
a source of material to be sprayed and pressurizing means therefor
when the shaft 46 is fully projected.
It is also noted that the yoke mount 50 for the nozzle 49 of FIG. 9
may be replaced by a gimball mount therefor and a plurality of
program controllable servo motors for positioning the nozzle to
direct one or more sprays of coating material against respective
areas of the mask.
Still another method and apparatus for selectively coator
depositing material against the surface of a mold cavity wall is
illustrated in FIGS. 10 to 14 which employs xerographic techniques
in which the mold itself is provided at a ground potential and a
coating or liner of photoconducting material defines all or a
portion of the wall of the molding cavity. A grid wire or electrode
shaped to conform to the surface of the mold cavity wall is first
used to uniformly charge the photoconductive liner, which charge is
thereafter removed from selected areas by means of a light pattern
as disclosed in U.S. Pat. No. 2,955,052.
FIGS. 10-13 illustrate apparatus for selectively depositing
material on the surface of a mold wall cavity by electrostatic
deposition means in which particles or atomized droplets of the
coating material are charged either negatively or positively and
are attracted to oppositely charged areas of the surface of the
mold. In FIG. 10, a mold section 51 has a molding cavity 52 which
is either coated with or defined by a liner 60 made of a
photoconductive insulating material such as vitreous selenium,
selenium-tellurium mixtures, zinc oxide in a ceramic binder, or the
like. The photoconductive insulating material is one which is able
to retain, while unexposed to light, an electrostatic charge on its
surface for a sufficiently long time interval to allow exposure and
development or other utilization of a formed electrostatic charge
pattern on its surface which, on exposure to activating radiation,
rapidly dissipates charge. The surface 53 of the mold cavity wall,
lining or coating thereof may be first uniformly charged by any
suitable charging means prior to creating a charge pattern by means
of light images projected thereagainst. In FIG. 10 the charging
means comprises a fixture 64 which is operative to position an
electrode 66 such as a corona discharge plate which is shaped to
conform to the surface of the mold cavity and is positionable
immediately adjacent thereto after the mold sections 51 and 61 are
separated as illustrated. Shell-shaped electrode 66 is insulatedly
supported off a base 65 by means of an insulating sheet member 67
and is charged by means of voltage in the order of 6,000 to 10,000
volts supplied thereto through a conductor 68 from a source of said
potential. The base 65 is supported at the end of the shaft 71 of a
lineal actuator 70 such as an air cylinder which is supported on a
base 75 secured to the end of a second shaft 73 of a servo device
74 which is operative to rotate 64 thereon and to longitudinally
move to position the electrode 66 within the cavity of the mold 51.
By a combination of program controlled operation of the servo means
(not shown) moving mold member 51 and/or the servo devices 74 and
70, electrode 66 may be brought into the immediate vicinity of the
surface of the mold cavity as illustrated and energized to create a
uniform charge pattern across said surface or the areas thereof
coated or lined with photoconductive material. Corona discharge of
electrical charge through the air gap between the outer surface of
the electrode 66 and the surface of the mold cavity wall may be
utilized to effect the charging of the latter or engagement of the
electrode thereagainst may be employed to effect said charging.
Other features of the apparatus illustrated in FIG. 10 include the
provision of a coupling means 69 disposed between base member 65
and the shaft 71 of lineal actuator 70 permitting removal of the
electrode 66 therefrom and its replacement with electrodes of other
shapes which may be utilized to charge molds having cavities of
different shapes. One or more fasteners 69' may be provided as part
of the coupling member 69 which may be loosened to remove the
electrode assembly and tightened to fasten a new assembly thereon.
For example, a single straight or bent corona discharge wire may be
secured to an insulating member retained by the coupling 69 and
will suffice for charging the surfaces of certain mold cavity walls
without resort to an electrode of the complexity of that
illustrated in FIG. 10 provided that it is properly positioned with
respect to the mold by the means illustrated. Notation 72 refers to
a self-winding reel supply means for the flexible line 68 extending
to the charging electrode 66 which reel is connected to a source of
sufficient high voltage potential through a switching means (not
illustrated) which is operative to supply said voltage to the
electrode at the proper instant during a cycle which will be
described. The mold member 51 is mounted on a plurality of rods 58
in accordance with conventional molding apparatus construction,
which rods are supported in sliding bearing by means of a plate 57
and are connected to an actuating device such as a hydraulic ram 59
for bringing the surface 54 of the mold into sealing engagement
with the surface 63 of the other mold member 61 and, in certain
instances, for prepositioning mold member 51 with respect to the
electrode 66 upon alignment of the latter with the cavity 52
thereof. Mold member 61 is shown supported on a stationary mount
63. Although not illustrated, the electrode means mounted on base
65 may also be shaped and operative to uniformly charge the surface
of the cavity 62 of mold member 61 if it is desired to also
selectively deposit material thereon by the means hereafter
described. Notation 55 refers to passageways in the mold member 51
for flowing one or more heat transfer fluids which are supplied
thereto and removed therefrom by means of multiple flexible
conduits 56 connected to one or more sources of said fluid or
fluids.
In FIG. 11, means for projecting a light pattern against the
charged surface of the photoconducting material defining the mold
cavity wall surface is mounted in a housing 76 supported at the end
of a shaft 77 of a lineal actuator 78 which predeterminedly
positions said housing in alignment with the mold cavity. The
housing 76 preferably includes, in addition to a light source of
sufficient intensity, the necessary optical projection components
and a mask such as photographic film disposed so as to provide the
requisite light pattern as one or more projected beams emitting
therefrom which predeterminedly intersects the surface of the
charged photoconductive material defining the molding surface of
the mold cavity to be selectively discharged by said light. The
operation of the light source in housing 76 is preferably
controlled by the same programming means controlling positioning of
the housing and the other operations occurring during a molding
cycle. A flexible wire 76W extends from the light source in housing
76 to a power supply through a switch (not shown) which is
controlled by said program control means.
After the photoconductive surface of the mold has been selectively
discharged to define a charge pattern thereon, droplet or
particulate material having a charge opposite to that of the
charged areas of the mold surface is flowed or sprayed thereagainst
by means such as that illustrated in FIG. 12 and the particles form
in a pattern substantially defined by the charge pattern against
the surface of the mold. The particulate spraying means illustrated
in FIG. 12 includes a spray nozzle 79 secured to the end of a shaft
82 of a lineal actuator (not shown) of the type described which is
controlled by the said program control means to project and
preposition said nozzle in alignment with the molding cavity after
the projection means 76 has been removed from the general vicinity
thereof. Notation 80 refers to a flexible conduit extending from
nozzle 79 through which particulate or atomizable liquid coating
material is controllably flowed by valve means (not illustrated)
which is also controlled by said programming means. Notation 81
refers to a flexible electrical cable extending to the spray head
79 which is connected to a source of high voltage potential and
electrode means disposed within said spray head for properly
charging the material sprayed therefrom against the mold so that
the particles dispensed therefrom will be attracted to the charged
areas of the mold surface. The operation of the apparatus is such
that excess particulate material flows from the mold cavity or is
deflected and expelled therefrom, a chute 83 is provided on shaft
82 for catching said material and means (not shown) are provided
for recycling the material dropped into the chute 83 to the source
thereof.
Although the means described for propositioning the electrode 66,
projector 76, and spray nozzle 79 of FIGS. 10 to 12 may be
separately mounted at different locations adjacent the molding
apparatus, a preferable arrangement is to mount all three on a
common rotatable base as illustrated in FIG. 13. The mount 75 for
the lineal actuators 70, 78 and 84 which have been described is
shown as a circular plate supported on a shaft 75' which is
predeterminedly rotated by any suitable servo means (not shown).
Thus each of the devices 66, 76 and 79 are respectively positioned
in alignment with the cavity or cavities of either or both mold
members by control of rotation of shaft 75' to perform the
functions described.
FIG. 14 illustrates a modified form of the hereinbefore described
apparatus in which the surface charging electrode, light pattern
projection means, and coating means are all provided on a common
mount and are sequentially operated to perform the described
functions. A single lineal actuator 85 is mounted adjacent the
molding apparatus and has a shaft 86 mounting a fixture 87 at the
end thereof on which fixture is mounted a corona discharge
electrode 66', a projector 76' of the type described and a housing
79' containing means for flowing charged deposition material
against the surface of the mold cavity. The shaft 86 of lineal
actuator 85 is not only longitudinally movable but is shown
provided with means for rotating same so as to permit
prepositioning of the electrode 66' mounted at the rear of frame 87
and the housings 76' and 79' with respect to the mold cavity. A
reversible gear motor 88 is mounted on the side wall of 85 and the
shaft 89 thereof has a bevel gear secured thereto and engaging the
teeth of the gear 87 operative to rotate shaft 86 without moving
therewith as the latter moves longitudinally. Slotted coupling
means between gear 87 and shaft 86 may be utilized to maintain the
gear in driving engagement with shaft 86 as the latter moves in and
out of the actuator 85. Notation 68 refers to a flexible cable
containing a fluid conduit for the material to be dispensed from
discharge means 79' and electrical wires extending to the electrode
66' and the light source within housing 76'. The cable 68 is shown
secured to shaft 86 and is sufficiently flexible to permit full
rotation and longitudinal movement of said shaft. Notation 68'
refers to an extension of cable 68 extending to the said source of
fluent deposition material and the control means for power for
energizing the devices 66' and 76'.
The apparatus illustrated in FIG. 14 may simply include the lineal
actuator 85 operative to project and retract the devices mounted at
the end of its shaft and/or rotate same as described. However, the
apparatus illustrated may also be operative to pivot or otherwise
move in one or more additional modes to preposition the molds
preparation devices in precise alignment with the mold cavity with
or without controlled movement of the mold cavity with respect
thereto.
Device 79' may comprise a spray nozzle of the type described in
FIG. 12 and/or other means for depositing mold coating material.
For example 79' may comprise an electron beam generating gun
including means for generating an intense electron beam and
directing same against the surface of the mold cavity wall and
means for introducing one or more materials into said beam,
vaporizing said material and causing same to be carried along the
beam and selectively deposited thereby against the mold cavity
wall. Such an arrangement would eliminate the necessity of
selectively charging areas of the mold wall cavity since the
automatic deflection control and operation of the beam of the
electron gun would suffice to effect the selective deposition of
material in the mold cavity for the purposes hereinabove
described.
In another form of the invention, the forces of magnetism may be
employed for either selectively depositing a particulate material
on a mold wall prior to molding or retaining a selectively
deposited particulate material on a mold wall until molding is
effected thereagainst or until said material is fixed and bonded to
the wall by heating. Various paramagnetic particulate materials may
be employed as the decorating or coating material sprayed or
otherwise caused to flow and be retained against selectively
magnetized areas of the mold wall. The particulate material may
comprise various thermoplastic resins loaded with magnetic oxides,
barium ferrite or other material rendering same paramagnetic
whereby it will be affected by a magnetic field and will be
retained against a magnet or material disposed in a magnetic field
of sufficient intensity. A suitable magnetic thermoplastic material
which may be utilized and may be magnetized whereby it will retain
itself against unmagnetized paramagnetic material such as iron or
steel or other materials such as aluminum, cobalt, nickle alloys is
a polyvinyl chloride filled with barium ferrite and known
commercially as Koroseal which is manufactured by the B.F. Goodrich
Company. If magnetized particles of such a polymer are sprayed
through a mask disposed against a surface such as the surface of
the mold wall cavity which is made of paramagnetic steel, the
particles will be magnetically attracted thereto in the shape of
the opening or openings in the mask. The particles may be melted in
situ after removal of the mask or retained in particulate form
magnetically held against the mold wall during admission of molding
material to the mold. If the mold wall or the hereinabove described
mold liner is either selectively magnetized along predetermined
areas thereof is is made of a composite of magnetic and
non-magnetic materials defining the molding cavity wall, the said
paramagnetic coating particulate material may be flowed or sprayed
against a larger area of the mold wall than that on which it is
desired to deposite and retain particles with the result that only
those areas of the mold wall which are magnets or are magnetized
will magnetically attract and retain particulate material, whereas
particulate material disposed against other areas of the mold
cavity wall will fall off or may be easily removed with air blown
against the mold cavity wall prior to molding.
In a particular form of magnetic mold wall operative to retain
paramagnetic decorating material, an insert is provided in the wall
of the mold made of a material capable of being permanently
magnetized. One or more cavities in the outer surface of the insert
define the contour of the decorating material to to applied to the
molded article. Magnetic thermoplastic particles as described are
flowed against the magnetic insert and into the cavities therein to
fill said cavities. Excess particles attracted to the other
portions of the insert are removed therefrom by air or mechanical
means such as a brush. The particulate material is melted in the
cavity in the insert or retained in particulate form until molding
material is admitted to the mold operative to either melt and fuse
with the particulate material or fuse same to the surface of the
molding upon solification of the molding material.
As stated, the apparatus hereinabove described preferably includes
a single variable programming device such as a multi-circuit timer
which is manually or automatically reset at the end of each cycle
and is operative to sequentially control such operations as
movement of one or more mold sections to open and close against
each other and to become prepositioned with respect to the
described mold processing apparatus; movement of each mold
processing device into working relationship with the mold cavity;
operation of the processing device; retraction of the processing
device to clear the mold cavity; temperature of the mold; and the
controlled flow of all materials including the mold coating
material, molding material and heat transfer fluid or fluids. Such
programming device is preferably of the type which may be adjusted
or varied without difficulty to provide a decorating and molding
cycle for fabricating many different articles. In a more
sophisticated form of the invention, such a variable program
control means may comprise means for reading a recorded or punched
tape or card, disc or drum containing command control signals which
are either generated in sequence per se or in accordance with
feedback signals generated by limit switches and/or sensing devices
operative to sense variables such as movements of components,
material flow rate, depth or coating, molding pressures, etc.
Controls for the various servo devices (i.e., solenoids which
control valves and motors driving mold members, pumps, valves and
the like) may be of the pulse activated bi-stable type or the
infinitely variable type controlled by variable analog type control
signals which are generated by the program controller as shown in
my U.S. Pat. No. Re.25,570. Pulse activated controls may be used to
start, stop and reverse motors or project or retract solenoids when
pulsed by signals generated by a multi-circuit timer or the
like.
In addition to providing means for disposing decorative material
against the surface of a molded article as described, the apparatus
and method may be utilized to provide materials other than
decorative against the surface of a molded article for serving
various purposes. For example, materials providing better or
different characteristics than the molding material may be
electrostatically adhered to one or more selected areas of the wall
or walls of a mold cavity as described to abrade, provide better
wear, lubricate, provide a particular rough or smooth finish,
conduct electricity, insulate, provide a porous or non-pourous skin
or perform some other function.
For providing a better wearing surface, the particulate material
may comprise a plastic such as a polyamide. For providing a
lubricated surface, said particulate material may comprise
molybdenum disulfide or plastic filled therewith. Various
conductive plastics, metals or compounds may be selectively
disposed against the mold as described to form conducting areas or
circuits on the surface of the molded part. Abrasive particles of
such compounds of tungsten carbide, silicon carbide, aluminum oxide
or the like may also be so disposed to become partly embedded in
the surface strata of the molded part.
A printing or selective article decoration process derivable from
use of the hereinbefore described apparatus comprises selectively
depositing thermoplastic particulate material on the surface of an
article or sheet of paper as descrete layers of said particulate
material in contours representing indicia or other decorations,
rendering said deposited particulate material semi-molten or molten
and while still in a semi-molten or molten condition, transferring
same from the first surface against a second surface such as a
sheet of paper or article, and bonding same in its original shape
to the second surface. The first surface on which deposition is
made may comprise a drum or printing plate and any means of FIGS. 1
to 13 may be employed to deposit and render the deposited particles
molten or semimolten.
If the apparatus hereinbefore presented or modifications thereof is
utilized for decorating or labling articles formed by blow molding
a parison or other shape between mold sections closed thereagainst,
then portions of the parison may be selectively coated or decorated
as or immediately after it is formed and prior to blowing thereof
to provide part or all of the surface decoration for the article
molded therefrom. Such decoration or decorations may be provided on
the inside and/or outside surface of the parison by a mask and
spray means disposed inside and or outside the parison and
operative to selectively coat atomized droplets or particulate
material against the surface of the parison which immediately bond
thereto. The particles of thermoplastic coating material may be
rendered molten or semi-molten on the areas of the parison on which
they are deposited or sprayed by the heat of the parison as it
extrudes and/or other heating means as described including means
disposed in the spray head, radiant heating means inside and/or
outside the parison, dielectric heating means surrounding the
parison or disposed on the mandrel or beam heating means as
described including laser or electron beam generating means mounted
on the extrusion head mandrel or exterior thereof. A stationery or
movable mask which is movable at the same speed as the parison may
be mounted on the mandrel which forms the inside surface of the
parison at the end thereof which extends beyond the end of the die
as may a spray head for particulate or atomized particles or
droplets of coating material which is operative to selectively coat
the inside surface of the parison prior to blowing same to shape in
the mold. By eliminating the mask, the coating liquid or
particulate material may be continuously sprayed from the mandrel
mounted nozzle after being delivered from a source thereof through
a passageway extending through the mandrel so as to provide a
uniform coating of material on the entire inside surface of the
parison. If the coating is sufficiently thick and remains
semi-molten, molten or liquid during blowing or is capable of being
stretched, it will remain contiguous during blowing and may be used
as a coating along the entire inside surface of the blown artcile
for imparting characteristics to the blown article not rendered by
the extruded parison material. If the parison material has a
tendency, for example to be porous or water absorbing, the coating
material may comprise, for example a thermoplastic or thermosetting
resin such as an epoxy, phenolic or urea formaldehyde, polyamide,
polycarbonate, phenoxy or other resin which will render the inside
of the article (such as a bottle) non-absorbing and non-porous.
Thermoplastic coatings so applied may set and integrally bond to
the blow molding material which may be polyethylene or other
suitable resin and thermosetting resins may air dry or otherwise
set thereafter on the inside of the blown article. In still another
form, the coating material may be applied as a spray to the inside
of the blown article while still in the mold by spraying means
mounted on the mandrel of the extruder inserted into the neck of
the blown bottle or through a separate injector such as the blowing
needle sometimes inserted into the wall of the parison and used to
blow same into the mold. The mandrel inserted into the open parison
or blown article, may also mount an electrode or electrodes such as
an electron beam generating means, glow discharge electrode or
other means operative to generate an electron beam, electrostatic,
ionic or other electrical field within the parison or blown article
with the mold or an electrode disposed outside the parison serving
as a ground or cooperating electrode to create the electrical
discharge phenomenon. Material such as a monomer in gas, vapor,
atomized or particulate form or vaporized metal may be introduced
into the volume defined by the parison or blown article from a
source of said material or electrode mounted on the extrusion
mandrel or derived from a source connected to a passageway through
the mandrel. If a monomer is so deposited against the inside
surface of the parison or blown article, it may be polymerized in
situ against said surface by the action of the glow discharge
means. If vaporized metal is so deposited, it may be protected by
depositing thereover or therewith a film or coating of
thermoplastic or thermosetting resin or monomer dispensed from the
end of the mandrel as described and, in the case of the monomer,
polymerized in situ against the inside surface of the metal or
other material deposited therebefore. If a bottle is so blow molded
and internally coated before removal from the mold, the coating
action may be followed by a filling action in which a product is
introduced through another passageway in the mandrel prior to
removal therefrom.
Referring once more to the form of the invention illustrated in
FIG. 6 wherein decoration material is first deposited onto
selective areas of a form 31 to provide layer formatione 27" on the
surface 32 thereof and is thereafter transferred to the surface 13
of the mold cavity wall, it is noted that the surface 32 of the
transfer form 31 need not conform to the surface 13 to which the
material formation 27" are to be transferred. Only those portions
of surface 32 which contain the decorating formations 27" need
conform to the surface 13 when the form 31 is moved adjacent
surface 13 to effect the selective coating or decoration thereof.
Accordingly, the surface portions of 31 against which material
formations 27" are deposited may be raised formations surrounded by
depressed surface portions of surface 32. In other words, the
surface 32 may be formed by machining, etching or molding similar
to that of a printing cut. Providing such a structure will permit
transfer of surface decorating material such as 27" coating
predetermined surface areas as defined by the raised portions of
the surface 32 in one or more of a number of manners. In a first
procedure, the form 31 is charged electrostatically or by direct
current means applied continuously thereto to a first polarity and
the particulate material is charged to an opposite polarity
thereto. Flowing such material as described against the entire
surface 32 will result in covering said surface therewith but only
that material disposed on the raised portions of said surface will
engage the surface (13) since the material disposed against the
recessed portions of surface 32 is disposed away from surface 13.
Transfer of the material 27" on the raised portions of member 31
may be effected by electrostatic means (i.e., where surface 13 is
charged so as to remove the particles comprising formations 27"
from the raised portions on which they are disposed); by magnetic
attraction means (if the particles are made of a paramagnetic
plastic such as vinyl containing barium ferrite and are either
magnetized or are attracted to the surface 13 of the magnetized
mold wall); by heating the surface 13 as described and rendering
the particulate material of formations 27" semi-molten and tacky
such that it adheres to 13; or by coating the surface 13 with a
tacky adhesive or plastic rendered semi-molten thereon and
operative to adhere all if not part of the particles of formations
27". The described procedures may be applied, in addition to
decorating articles as described, for printing sheet material of
flat or irregular contour wherein member 31 may be shaped as a
printing plate or die with raised cut formations in the surface 32
thereof. The paper, plastic, metal or glass sheet material may be
heated to melt the particles of formations 27" or a drum or platen
disposed therebeneath may be up heated while the form 31 may be
water cooled through internal passageway flow of coolant to prevent
the particulate material disposed on the recessed portions of the
platen 31 from melting. Thermoplastic resin coated sheet material
may have its coating rendered semi-molten by passing same over a
heated platen or drum or by dielectric heating means to bond the
particles of formations 27" thereto.
If relatively thick formations are desired on the surface 13 of the
mold or a sheet material, particulate material may be removed from
the raised portions (defining formations 32) by means of a brush
wiping same or air blown thereacross while the particulate material
in the recesses remains. Heating transfer member 31 thereafter will
result in rendering the particulate material in said recesses
semi-molten or molten and, if it is provided to a depth whereby
when heated it is at the level of the surfaces of the raised
formations of the cut, then it may be engaged against and bonded to
the surface 13 of the mold or a sheet material. If the member
containing the surface (13) against which it is desired to transfer
predeterminedly shaped formations 27" while semi-molten, is itself
thermoplastic or resilient, then it may be deformed by the raised
portions of the heated transfer member to compressively engage the
molten or semi-molten formations contained within the recesses of
the printing member 31. If the particulate material filling the
recesses in a transfer member such as 31 is a heat expandable
plastic such as polysyrene containing a blowing agent, it may be
expanded while the transfer member (31) is disposed against the
surface (13) of the mold or sheet against which it is desired to
mold or secure the expanded plastic and while either the transfer
member or the member to which it is to be secured are heated to
effect said expansion and formation of the plastic. The surface of
the article, sheet or mold to receive and retain the expanded
plastic decorations may also be coated with a thermoplastic
material or adhesive operative to bond the expanded plastic
formations thereto so that the form 31, when removed from the
vicinity of the member against which it is compressed will do so
without retaining the expanded plastic formations in its recesses.
A suitable self expanding plastic commercially available is Dylise
expandable polystyrene which is available in small pellet or
particulate form and contains from 5% to 8% of a blowing agent. In
using such material, the raised portions of the form 31 preferably
engage the surface of the mold, article or sheet adapted to receive
and retain the expanded formations and define essentially a closed
mold or mold cavities therewith and the depressed formations in
form 31. Heat transferred to the form contained beads either from
the form and/or the member against which the form is compressed may
be operative to expand the beads and bond same into molded
formations defined by the shape of the cavities and the surface
against which the form in which the cavities are provided is
compressed. Formations of expanded plastic provided on the surface
of a mold wall may be made integral with further expandable plastic
formed thereagainst thereafter in the mold.
In still another form of the invention, thermoplastic material in
particulate form may be disposed as a layer on the surface of an
article, mold or sheet material and held thereon by electrostatic
means, magnetic means or gravity. Thereafter, a heated die having
raised and recessed portions such as an embossing die or printing
cut may have its raised portions brought to bear against the
particulate material on said surface to heat and melt these
particles aligned with the raised portions thereof. Thereafter the
melted particles may form contiguous formations which either remain
on the surface the particles are originally applied to or are
transferred to the raised portions of the cut or die. The
non-melted particles on adjacent areas may be removed thereafter by
air blown thereagainst and/or gravity means.
A layer of thermoplastic particles may also be selectively heated
by scanning selected areas thereof with an intense radiation beam
such as a laser or electron gun generated beam which beam is
operable to intersect, melt and fuse certain of the particles to
the exclusion of others as described. The beam may be controlled by
a video signal or by signals generated by a hand operated key set
which cause the beam to scan areas representative of characters
associated with the keys depressed. The heat of the beam may also
be operable to fuse the particles to the surface of the substrate
on which they are disposed. The substrate on which the particles
are disposed may comprise a sheet which is driven to bring new
portions thereof into the scanning field of the beam while the
particles are continuously flowed to the surface and the unfused
particles are continuously removed therefrom after scanning by the
beam. The sheet may be driven around the upper and side surface of
a support while particles are flowed onto an upwardly facing
surface of the sheet after which the sheet may be guided at an
angle to the horizontal and the particles removed by gravity. The
beam may also be generated at an intensity to selectively burn
material fused to the surface of the substrate such as material in
the form of characters to burn and brase selected characters.
FIGS. 15 and 16 show structures in dies applicable for selectively
applying material as described to mold or article surfaces. In FIG.
15 a die assembly 91 is composed of a die base 92 having an outer
stratum or member 93 welded or otherwise secured to the base 92 or
formed integrally of the same material thereof. The member or
portion 93 is composed of recessed portions 94 and raised portions
95 the outer or upper surfaces 95' of which are adapted to receive
coating material as described and compress said coating material
against the surface of the work to apply or print same on said
surface. Extending along each raised portion 95 is a passageway 96
through which a heat transfer fluid at the desired temperature is
circulated by a pump or other means extending from a heater for
transferring heat thereto. The heat transferred from the fluid
through the wall of portion 95 is sufficient to render the
particles disposed against surface 95 molten or in a fusible
condition such that it may be transferred partly or in its entirety
to a surface engaged by the die. Notations 97 and 98 refer to
portions of the same passageway or passageways extending through
the member 93 adjacent the raised portion thereof for transferring
or conducting a coolant fluid adjacent the raised portion 95 to
maintain the surfaces 94' adjacent raised surfaces 95' at a
temperature below that at which the molding or coating material
will fuse or melt so as to prevent said material from coating said
adjacent surfaces. The surfaces 94' may also be coated with a low
friction coefficient material such as polytetrafluorethylene to
prevent the coating and buildup of coating material thereon.
FIG. 16 shows a modified form of die structure 100 composed of a
base 101 having a channel 102 formed therein into which channel a
rectangularly cross sectioned tubing member 103 is fitted and
secured. The passageway 104 extending through the tube 103 serves
to conduct heated liquid or gas to melt or fuse material disposed
against the outer surface 105 of the tube for the purpose
described. The tube 103 may be friction fitted, welded or soldered
in the channel 102 in member 101 and may be shaped to a desired
contour or bent to confrom to the channel 102 for effecting the
desired coating or welding action.
The die structures illustrated in FIGS. 15 and 16 may also be
utilized as heat welding dies for welding plastics and metals. For
example, hot gas or liquid at temperatures ranging from several
hundred degrees to two or three thousand degrees F. may be flowed
through the passageways 96 and 104 for heating portions 95 and 103
to a desired temperature necessary to melt or weld material
compressed by said die. The entire die or the portions 93 and 103
may be made of suitable high temperature resistant metal or ceramic
material such as tungsten, tungsten carbide, titanium, titanium
carbide, aluminum oxide, graphite, nickel alloys, dispersion
hardended steel, etc. to resist corrosion and heat deformation or
may be flame coated with such materials. Depending on the
temperature of the heat transfer fluid passed through passageways
96 and 104, the die structures illustrated may be used in a
suitable press or welding fixture means to predeterminately weld
aluminum, steel, copper as well as many plastics by passing heat
transfer fluid through the passageways to heat and in certain
procedures, cool the die thereafter during a preprogrammed welding
cycle. In other words, operation of the welding press, transfer of
the heat transfer fluid through the passageway(s) and, where
applicable, coolant through said passageway(s),etc. may be
controlled by a master controller such as a multi-circuit timer,
master controller or computer. Means sensing variations in the
temperature of the heat transfer fluid may be used to generate
control signals for controlling said temperature at a preset or
preprogrammed level during the welding procedure.
In another form of the invention, particle dispensing means and a
charged spray mask may be provided in an arrangement such as a
typewriter or character printer. The mask may comprise a ball,
drum, disc or tape driven continuously or intermittently to bring
different character shaped mask openings into alignment with the
spray or dispensing head for printing lines of characters on a
sheet or other object. The dispensing head may be operated to
dispense small quantities or puffs of liquid or solid particles or
charged thermoplastic or other material as described containing the
same electrostatic charge as the electrical charge of the mask so
that the particles will not deposite on the mask but will all pass
through the opening in the mask which is in direct alignment with
the stream of particles.
While the entire mask may be charged by commutating means located
remote from the opening of the mask through which the particles are
being directed at the substrate to be printed on or decorated, one
or more electrodes may be disposed adjacent to the stream of
particles in rolling or sliding contact with the mask, which may be
made of sheet metal or other suitable chargable material, so as to
concentrate and control the charge. The mask may also be coated
with a material such as polytetrafluorethylene to prevent the
sticking of any particles which may stray thereon and said
particles may be wiped or blown offby an air jet directed
thereagainst remote from the axis along which particles are
dispensed. A common mount may be provided for the dispensing or
spray head for particles which also mounts the said electrodes
contacting the mask and the means for rotating or otherwise driving
the mask past the dispensing head. The common mount may be movable
across a page of print receiving paper or substrate or said
substrate or page may be moved with respect to the common mount.
The mount and sheet may also be movable relative to each other as,
for example, in a conventional typewriter or the IBM ball
typewriter with the dispensing head disposed inside the ball or
drum or behind the disc or tape. In operation, small predetermined
quantities of particles may be dispensed from the spray head or
nozzle each time a solenoid is pulsed when or after a selected key
of a keyboard array of character keys is depressed upon the
selected character opening in the mask coming into alignment with
the spray axis, to open a valve in a line or gas pressurized
particles or to operate a piston or other device for ejecting said
predetermined quantity of particles therefrom towards the aligned
mask opening. Particle charging means as described may be provided
in the dispensing head and similarly charged particle guide means
in the form of charged wires or plates may form a stream of the
particles ejected from the dispensing head and to guide said
particles towards the mask opening. Of the embodiments illustrated,
it is noted that the mount for the spray head 24 may be movable
across a sheet of paper while the shell 24 may be pivotally mounted
or gimball supported and power rotated about two axes to provide a
printing arrangement for flat or irregular surfaces for printing
any desired arrangement of characters on said surfaces.
A typical printing apparatus may comprise a bed such as a
conventional typewriter bed, flat platen typewriter bed, line
printer platen or the like with means for guiding and driving a
sheet of paper therethrough past the described printing means which
is also supported by said bed. If the mask is a disc or flexible
ribbon with openings in the shapes of characters, it may be driven
by a constant speed gear motor or a stepping motor in an endless
path on a mount or transport supported by the spray head mount.
Mechanical and/or electrical means may be provided to synchronize
the dispensing of particles with the movement of the mask so that
the particles will flow through the openings in the mask selected
to print the desired character or shapes on the substrate. For
example, the means driving the mask may comprise a constant speed
gear motor or a stepping motor having an analog-to-digital
converter coupled to its shaft so as to generate digital signals
when each character of the mask comes into alignment with the spray
or dispensing axis. By programming a comparator with signals
generated, for example, by depressing character keys of a keyboard
and representative of a selected character or mask opening, the
comparator may be operated to generate a control signal when said
mask opening is so aligned with the spray axis and may be used to
close a switch or operate a solenoid or motor for pulsing particles
from the spray head towards the mask opening.
Since the number of particles required to provide each character
print may vary from one character to the next, the number of
particles dispensed may be varied in accordance with signals
generated by each key of the keyboard depressed. This may be
effected by varying the duration or voltage of the key generated
signals and applying said variable signals to operate the solenoid
or other device utilized to dispense particles from the head in a
variable manner so that more or less particles are dispensed
depending on the key depressed. If the particles dispensed are
solid particles, a heating means such as a resistance heating
element, laser or other means may be disposed adjacent the mask to
direct heat against the particles before, as or after they become
deposited on the substrate so as to melt and fuse same to the
substrate. The same laser used to fuse and bond said particles to
the substrate may also be selectively operated to erase characters
by vaporizing the material thereof for correction purposes. A
computer may also be used to control the printing operation by
generating signals simulating the key genated signals
described.
It is noted that the apparatus hereinbefore described and
illustrated in the drawings may be modified to effect the
predetermined positioning of articles in molds such as blowmolds,
injection molds, rotational and casting molds where it is desired
to mold composite articles. For example, plastic, metal or ceramic
reinforcements, inserts, decorations or otherwise operative
preforms may be individually held and transported by the pivoted or
lineally operated transfer devices of FIGS. 6 to 9 and inserted
into subcavities in the mold wall defining the molding cavity or
otherwise attached to the surface 13 in a manner such that, when
molding material is molded thereagainst, it will secure said
inserts to the plastic making them part of the molding. The form
31, for example, of FIG. 6 may be replaced by a jaw, chuck or other
fixture such as a gravity feed chute or air fed recepticle for
small parts which is operative to advance against or towards the
mold cavity wall when the mold is open and insert one or more parts
held thereby into sub-cavities in the mold wall adapted to retain
same in place during molding but shaped to permit the parts to be
removed when the molding is pulled out of the mold. If the form 31
is composed of a clamp or motor operated jaws, it may be
automatically operative to seize a part on a conveyor or chute
disposed adjacent to the transfer device, transfer the part to the
mold and insert the part into a hole or subcavity in the mold wall
13, weld, bond or otherwise secure it thereto. If the mold insert
is light enough in weight it may be temporarily held in place by
charging same electrostatically and holding the part against a flat
or shaped portion of the mold wall so shaped as to prevent lateral
movement of the part held thereagainst by static electricity. The
part may also comprise a sheet or film of decorative material such
as printed plastic held against the form 31 by air suction,
clamping or other means during its transfer to the surface of the
mold and retention thereon by electrostatic force.
In yet another form, modified forms of the apparatus described
above and illustrated in the drawings may be utilized to provide
inserts such as valves, filling spouts, neck reinforcements and the
like to be secured to the walls of blow molded articles such as
containers. For example, modified forms of the devices shown in
FIGS. 6 to 9 may be utilized to transfer and insert valves and neck
reinforcements into retaining cavities of mandrels such as
extrusion die mandrels over which plastic material is extruded to
form parisons to be blown into containers as by means of the
apparatus shown and described in my copending application Ser. No.
889,010 filed on Dec. 12, 1969 as a continuation of Ser. No.
594,924 filed Nov. 16, 1966 for Apparatus and Method for Molding
and Filling Hollow Objects. Said rotatable or lineally movable
fixtures and transfer devices shown in FIGS. 6 to 9 of the instant
application may be disposed below the extrusion die mandrel and
timed in their operation or interlocked to advance and insert
valves and/or neck reinforcements into the extrusion mandrel as
shown in FIGS. 1 and 3 of said patent applications immediately
after the blow molds are separated and the molding previously
molded therein has been removed to prepare the die for the next
molding operation.
In yet another embodiment of the invention described above, the
particles deposited on the substrate may be liquid or solid
particles of paramagnetic material or contain such material as
chromium dioxide, barium ferrite such as Ceramagnnet B.G.
manufactured by Stackpole Carbon Company of St. Marys, Penna. or
various magnetic ink pigments such as manufactured by Wright
Industries of Brooklyn, N.Y. These materials may be dispensed in
liquid ink bases or solid thermoplastic resins such as
polystyrenes, polyvinyl chlorides, etc. and may be dispensed from
the described spray heads and selectively deposited on the
substrates described such as a sheet of paper, article or mold
cavity wall by generating one or more magnetic fields along the
path of travel of the particles and employing said field to either
fixedly control the path of travel of the puffs of particles or
stream formations thereof or deflection controlling said particle
stream to cause the particles to variably deposite on the substrate
in any particular outline or shape thereof such as in the shape of
characters. In other words, the stream of paramagnetic particles
may be horizontally and/or vertically deflection controlled to
essentially write with said particles on the substrate by disposing
suitable electromagnets along the path of the particles and
variably energizing said magnets with time so as to vary the
intensity of the magnetic fields with time to variably deflect the
particle stream as the substrate is either held stationery or moved
with respect to the dispensing head for particles. Upon striking
the substrate, the particles may either be magnetically held
thereagainst if the substrate is magnetic or paramagnetic such as
sheet steel, or may be bonded thereto by adhesion and/or fusion
resulting from rendering the particle material molten. Key operated
or computer controlled means may be used to predeterminately
provide deflection control-signals for variably controlling the
deflection controlling magnetic fields along the path of travel of
the particles. The same type of deflection yoke means or a modified
form thereof employed to magnetically deflection control the beam
of a cathode ray tube and the circuit for controlling said magnetic
yokes magnetic field may be employed in the above described
magnetic particle control apparatus. Particle stream generating
means may include the described dispensing head operative to
generate a stream of individual particles or droplets or clusters
of particles each of which is deflection controlled to intersect a
different area of the substrate to form characters and other
indicia or surface decorations.
* * * * *