JPS6323764A - Method and device for coating and curing vessel - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application and Prior Art Soft drinks, such as carbonated soda, are commonly packaged in plastic containers, known as PET containers. In addition, other plastic containers are being used and developed for beer, salad dressings, and other foods, and for cosmetics, pharmaceuticals, and other commercial products. Because plastic containers have a relatively short shelf life, carbonated soda or other products lose their carbonation or freshness in a relatively short period of time, after which they cannot be sold to consumers. There are protective coatings that can be applied to the outside of the PET, making the container less permeable and allowing the beverage to be stored under pressure for a longer period of time, thereby increasing the durability of the packaging! f Extend life. Other protective coatings are being used or developed for other types of plastic containers to extend the shelf life of the packaging.

SUMMARY OF THE INVENTION The present invention is directed to a method and apparatus for painting and curing plastic containers, which handles plastic containers and moves them quickly and efficiently through painting and curing equipment, and provides suitable Painting and curing are guaranteed, resulting in a container with maximum life expectancy due to the protective outer coating.

The method and apparatus for painting and curing containers according to the invention can be formed as part of a line of container operations that includes forming, cleaning, painting, curing, printing or labeling containers and filling them with products to be packaged. It is preferable that Such equipment is coupled to container conveyors, single fillers and handling equipment to achieve the high handling speeds necessary for economical and efficient production.

SUMMARY OF THE INVENTION In the case of the present invention, co-pending U.S. Patent Application No. 647
．． No. 297 (September 4, 1984), the coating and curing equipment is preferably fed by a container transport system. Such conveying systems generally include:
It includes a conveyor for feeding unpainted plastic containers to a flight conveyor in a generally horizontal position that moves in time with a series of carrier devices. A suitable carrier device is disclosed in co-pending U.S. Patent Application No. 657.24.
No. 4, "Rotating and Retractable Container Holding Devices and Conveyors Thereof," J, dated 1984/10/3.

A carrier device engages the neck or mouth of each container and transports it through the coating and curing system and supplies the painted and cured containers to the removal conveyor. The carrier effectively covers the mouth of each container, thereby confining the protective coating to the external surface of the container. The carrier device then moves as it is conveyed, positions the container into the coating chamber, and rotates the container within the coating chamber to ensure a complete and uniform coating of the container and to provide sufficient rotational motion. , so that the paint is applied evenly without dripping.

After the coating has been applied, the container remains attached to the carrier M and is conveyed along a winding path through a curing oven to complete curing.

In another aspect of the invention, the coated container is transported through a curing oven and subjected to a combination of radiant and convective heat curing to provide the exterior protective coating. The carrier moves along a winding path to transport the containers up and down the oven. Each vertical path forms a separate chamber that selectively applies radiant heat to the entire painted surface of the container being cured. In addition, each vertical path is supplied with heated air to convectively cure the container. The curing oven has one or more vertical paths depending on the required production rate and residence time required to cure the coating.

In a preferred form, each vertical channel is equipped with a radiant heat source at the bottom of each channel for radiant heat curing. Convective air circulates through each path and is heated to a predetermined temperature by a radiant heat source to convectively cure the container at the top of each path.

A control system is equipped to regulate the speed and amount of curing air to ensure proper curing.

The oven can include one or more zones with different curing conditions for temperature and humidity to provide curing conditions particularly suited to the needs of various types of containers and protective coating materials.

Each area can be equipped with a humidifier where humidity is required for proper curing of a particular coating.

In employing the radiant heat and convection air curing oven of the present invention, the external protective coating is cured simultaneously with application. In addition, the paint is cured from the inside out, which prevents "scraping" that occurs when the outside is painted and cured first, and prevents the hardening of the paint below the surface, a condition that prevents the subsurface from erupting. In some cases, ``severe cracks'' occur.

It is an object of the present invention to coat and cure containers, in particular plastic containers, by exposing substantially the entire outside of the container, applying an external protective coating to the outer surface of the container and subsequently curing said coating. The object is to provide a method and apparatus such that the container is ready to receive a consumable product.

Another object of the present invention is that after painting and curing operations,
The purpose is to hold and rotate each container.

A further object of the invention is to provide each container with a protective coating so that the entire external surface of the container is coated with a protective coating, while the interior and neck of the container are shielded and unpainted and furthermore the coating applied is hardened. The purpose is to grasp it at its open end.

Another object of the present invention is to provide a transport system for receiving, holding, rotating, and moving plastic containers in a generally horizontal direction along a tortuous path through a painting room and a curing room.

Another object of the invention is to provide a means for rotating the containers as they are transported through the painting and curing chambers.

Other purposes include rotating at high speed to ensure an even coating when the container is spray-painted in the painting chamber, then reducing the speed of rotation to ensure a uniform coating within the painting chamber, and then reducing the The object of the present invention is to provide a method and apparatus for controlling and maintaining a uniform protective coating thickness without dripping.

Other objectives are the desired production rate, i.e. 25 to 1
The objective is to provide a system with selectable line speeds in the range of 50 feet (7.82 to 45.72 meters).

Another object is to provide an apparatus for curing external protective coatings from the inside out.

Another object is to provide an apparatus for curing external coatings by means of radiant heat and convective air.

Another purpose is to provide circulating convective air heated to a desired temperature by a radiant heat source.

Other purposes include various types of containers and coatings,
The object of the present invention is to provide a curing oven having multiple zones for various curing conditions.

Another object of the invention is to equip the bottom of each curing oven path with a radiant heater panel to effect radiation curing to a contour that completely covers the surface of the bottle.

Another purpose is to provide a humidification system for certain coatings that require elevated temperatures before beginning the evaporative curing process.

Another object of the invention is to provide an oven designed with standard dimensions for ease of manufacturing, shipping, and assembly in a vessel working plant. - Other objectives will become apparent to those skilled in the art upon understanding the specification or practicing the invention.

Referring to FIG. 1, the present invention is illustrated diagrammatically, and the language is to receive containers at a loading station 12, transport the containers from the loading station to a protective coating chamber 14, and then apply protective coating. It includes an endless conveyor member lO, shown in dashed lines, for transporting the paint to a curing chamber 16 where it is cured. The containers then move to a discharge station 18 where they are conveyed away by a conveyor to a continuous operation where they are filled with carbonated soda or kelachap, salad dressings, and other consumable products. As described in detail below, the containers are conveyed generally horizontally by an endless conveyor member and travel in a tortuous path through the painting and curing chamber.

A container transfer system suitable for use with the present invention is described in the aforementioned co-pending U.S. patent application Ser. No. 641.291, and as shown in FIG. 26 and transfer conveyor 28, the transfer conveyor includes an inlet conveyor 30 that receives individual containers between successive flights 32 and a flighted container conveyor 34, with a neck After the container is reoriented from the vertical direction to the horizontal direction by the matching guide 36, the container is supported and positioned. The construction and shape of these flight conveyor members are suitable for the container shape shown in FIG. ) The shape of the flight section of the three-feed conveyor can be adjusted as desired to accommodate different container shapes, including cylindrical containers, as disclosed in co-pending U.S. Patent Application No. 647.297. It should be understood that modifications can be made.

Container transport conveyor IO moves in time with transfer conveyor 28 and includes a container transport device 38 that engages and grips the containers at their open ends and transports the containers in a generally horizontal direction through the painting and curing chamber. Each container conveyor is arranged at the same time and interval as the route A and the route B along which the containers move on the conveyor.
and move along. In addition, the container transport device is aligned with each container such that each device engages and grips the neck of the container by extending the device across the space between parallel paths A and B. do. After the container is securely gripped, a container transport device transports the container through successive painting and curing operations, following the paths in which the transfer conveyor and the transfer conveyor diverge.

The container transport device is disclosed in pending U.S. Patent Application No. 647.297.
In its application, each device is mounted on an endless conveyor 10 and includes an inner housing 40 and an outer housing 42 rotatably mounted to the inner housing at a roller joint 44. It is sufficient to understand that it has a head or chuck 46 which engages the open end of the container. The inner and outer housings are centrally mounted to be axially slidable relative to the pin 48. A cam follower 50 on the inner housing is equipped to cooperate with a cam member 52 to effect this axial movement. To load a container onto the transport device 38, a cam follower 50 engages the surface of the cam member 52, causing the device to extend axially against the compressive force of an internal spring 56 (FIG. 4). . Grasping head 46 and container 2
As the two move in time with each other, the heads engage and secure the individual containers, as shown on the left side of FIG. The container holding device 38A (FIG. 2), which is not engaged with the container, retracts through the cam gap 58 (FIG. 2) under the force of its internal spring 56 to transport the container through the painting and curing operation. Move along a different route than the moving carrier.

FIGS. 4 and 5 illustrate, respectively, the location and operation of a container holding device that receives a container, engages the cam surface 54, and moves along the work path, and the device that does not. In FIG. 4, the apparatus 38 places the container 22 in the coating chamber 14 and applies a protective coating 60 by a nozzle 62. The position of the container within the chamber is determined by the placement of the cam surface 54 acting on the cam follower 50. Drive belt 6 on drive wheels 66 arranged on the side of the holding device
4 is driven by a shaft 68. The drive belt engages belt member 70 for the purpose of rotating outer housing 42 and container within the coating chamber. Such rotation ensures that the vessel is evenly coated during the eruption.
This is necessary to prevent paint from dripping from the container during spraying and before the paint has hardened.

It is observed that by gripping the neck of the container, the entire outer surface of the container can be secured. In addition, the neck itself and the interior of the container, which do not require painting, are shielded from painting.

The preliminary chamber 72 houses a vibrator 74, which injects water into the painting chamber.
7B to supply a desired level of humidity in the room;
and prevent paint from entering the preliminary chamber. In FIGS. 4 and 5, the vessel holding device is oriented horizontally and moves vertically from rails 78 and 80 secured to bracket 82 through a cantilevered coating chamber. Container holding device 38 in FIG. 5 is not in operation because it has not received a container from the transfer conveyor. Thus, the device moves without rotation within the prechamber 72 with its head 46 completely retracted and its cam follower 50 not engaging the cam surface 54.

Referring to FIGS. 1 and 3, the container transport conveyor 10 includes a coating chamber 14 and a curing chamber or oven 16.
It is configured to pass over spaced apart sprockets 84 so as to pass through a tortuous path. The conveyor carrying the containers is moved vertically down the path as the conveyor engages the drive belt 64 to rotate the outer housing of each conveyor and the container 22 being conveyed at the outermost end of each device. Follow. The container rotates at a considerable rotational speed of 600 to 1000 revolutions per minute (preferably approximately 800 revolutions per minute) as it passes through the painting area within the painting chamber; this rotation of the container ensures uniform coating of the container within the painting chamber. It has the effect of making it something. Continued rotation of the container is then slowed down to prevent paint dripping and ensure uniform paint distribution.

The drive belt 64 shown in FIG. 3 rests on appropriate pulleys 88 and is driven by a drive motor and gearbox 90.

When the conveyor enters the curing chamber, a rotatable conveyor joint engages a drive belt to rotate each container, for example at 800 revolutions per minute, to apply the protective coating. This rotation provides a uniform coating on the container. After being extracted from the painting area, the container holding device engages at its rotatable joint a friction rail 92 that extends from point A to point B along the path of the conveyor outside the painting room. The rotatable joint then engages a second drive belt 94 mounted over a pulley 96 and
belt 98 and belt 100 to continue rotating the container to ensure completeness and uniformity of the coating. For this purpose, the rotation speed of the container should be 40-1 per minute.
00 revolutions is appropriate. After leaving the painting room, the container is again moved to the third drive belt 104 between points C and D of the conveying path.
and subsequently engages a drive belt 106 that rotates the container between 40 and 100 revolutions per minute as the container travels a tortuous path through the curing oven.

As shown in FIG. 1 and FIGS. 6-9, the curing oven 1
6 comprises, in its general form, successive upright units, each forming a standard component of a curing oven. Typically, a curing oven has a left-hand module 112 and a right-hand module 114, each located at the entrance of the container. and the outlet from the oven, and together with an intermediate module 11B of similar design form the first and last passes of the oven. The concept of standardization facilitates design, manufacturing, final assembly, operational maintenance and repair, as well as provides flexibility in working with different vessels in a working plant. A curing oven includes two or more zones, each with a curing environment adapted to a specific temperature and humidity appropriate for a given container and coating composition, and each zone is individually adjusted to Preferably, it is adapted to provide the desired changes required for the curing process of such containers.

A preferred curing oven is illustrated in FIG. 6 and comprises a plurality of right side modules 114, middle modules 116 and left side modules 112 joined at several interfaces 118.

The left module has an oven inlet 121 and a descending passage 120 from an ascending vertical passage 122. Each intermediate module has an ascending path 126 and a descending path 128;
The right module has a descending path 1 to the oven outlet 132.
24 and an upward path +30.

Each module 110 is an upright box-shaped structure enclosed by a bottom panel 134, a roof 136 panel, and front, back, and side panels 138. The front panel of each module has an elongated opening 140 providing an entrance for container transport 38 and containers 22 to each module's curing chamber. The openings 140 are continuous from module to module, forming a cavernous or tortuous path for the container to travel. The rear panel has hinges 14
1 with an inlet J5i 142 and a latch 144 to provide entry into the interior of each vertical path. It is one aspect of the present invention to provide radiant and convective heat curing for painted containers. The radiant heat energy required for curing depends on the composition of the coating; for example, ultraviolet or infrared radiant energy can be used. Additionally, convective curing involves heating the curing medium, preferably air, with a radiant heat source.

In a preferred embodiment of the invention for curing protective coatings on PET containers, infrared radiant energy and convective air are used in each vertical pass through the oven. Preferably, the infrared heat source occupies the bottom half of each path and the convective curing occupies the top half. In this manner, the containers passing through are alternately subjected to convective and infrared curing from the entrance to the exit of the oven.

Accordingly, the interior of each module includes a radiant heat source 146 that generates curing radiant heat toward the container coating station 48. As shown in Figure 7.8.9, the radiant heat source preferably comprises a series of infrared panels 150 adjustably mounted within the oven by suitable brackets 150. The infrared panel extends approximately over the lower half 153 of the oven path and is configured to emit infrared radiation onto the containers it passes. As shown in Figure 8,
The panel 150 forms a shape particularly suited to a given container shape and surrounds a container base 154 that surrounds a container neck 156.
extending along an arc of a half of the container from the centerline of the container adjacent to the container. Each container rotates and its entire external surface is exposed to infrared radiation, so the infrared geometry represents the most economical curing configuration. Additionally, with this configuration, the infrared radiation can be directed to selectively provide radiation density at an optimal level depending on the curing requirements of different parts of the exterior of the container. for example,
The infrared panel closest to the neck of the container, which is considered to be the part of the container that is difficult to cure, is capable of adjusting its radiation to the neck with respect to its distance and direction7, - the upper half 158 of each path is used to paint the container Provided with circulating convection air for curing purposes. As best seen in FIG.
Duct 16 recessed and supported by upright member 162 at 4
Cycles through 0. The circulation duct includes a blower or fan 166 that drives air from the lower end of each passage through a supply header 168 for the purpose of heating the air with a radiant heat source. A suitable control system in conjunction with thermocouples (not shown), such as silicone regulators, maintains each radiant panel at a predetermined temperature or thermal radiant density to heat the circulating air to a predetermined curing temperature. provided for. A silicon control regulator, set at a predetermined temperature and responsive to the temperature sensed by the thermocouple, adjusts the wattage to the radiant panel to maintain the predetermined temperature. The convective air circulates up and through each path curing the incoming containers, then returns through the exhaust header 170 to the air circulation duct for continuous circulation within the curing chamber. The supply and discharge headers through which the air circulates include dampers 172 to control the volume and velocity of the convective air. The particular protective coating depends on the relative velocity of the air passing through the container. It is known that it is a feeling. This sensitivity is taken into account in the calculations of the present invention, and the air circulation is appropriately adjusted by adjusting the baffles so that the containers reside at different rates as they pass through the curing zone.

For certain applications, relatively high humidity is preferred, allowing the temperature of the protective coating to rise to elevated levels before evaporative curing of the coating begins.

For this purpose, a series of steam or water mist injection nozzles 174 can be equipped to maintain the humidity of the air circulating in the room at a preselected level, or to select areas according to the desired curing cycle. It is possible. High humidity inhibits evaporation of the paint until it reaches the proper curing temperature.

Preferably, the curing oven is divided into separate areas with different temperature and humidity conditions according to the specific stage of the curing process. vertical panel 176
Alternatively, by providing baffles and separating the interior into several chambers, a separate air circulation system is provided to each area, circulating air of different temperature, humidity and velocity.

During operation, the containers are transported by means of individual holding devices on a transport conveyor through a tortuous path formed according to each path of the curing oven. When the container enters the curing oven, it is rotated by its conveying device at a speed sufficient to ensure that the paint applied on the container is maintained uniformly and at the same time for infrared curing placement within the infrared portion of each passage. , exposing the outer surface of each container. The container first enters the upper convection curing area and passes through an oven where it undergoes alternating convection and radiation curing. After the container, which rotates at 40-100 revolutions per minute, passes through the adjacent lower section, it enters the convection hardening section and is hardened in the upper adjacent passage by convective air. Convection air is continuously circulated by air circulation ducts,
Maintains the increased temperature according to the infrared density set on the infrared panel.

After passing through the curing oven, the cured containers are passed along a take-off conveyor where they are further subjected to, for example, labeling, filling and other container operations.

It will be apparent to those skilled in the art that various modifications can be made to the method and apparatus of the present invention without departing from the spirit or scope of the invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic representation of the method and apparatus of the invention including a loading area, a painting area, a curing area and a discharge area connected by a conveying system shown in dotted lines; FIG. FIG. 3 is a side view of a container moving through the paint room and a cut away elevation showing the container transport system including the pull conveyor, timing screw, transfer conveyor and container holding device conveyor; FIG. a drive mechanism for rotating; FIG. 4 a cross-sectional elevational view of a container holding device for transporting containers through the painting chamber; FIG. 5 showing the relative position of the device not holding a container; Figure 6 corresponds to Figure 4; Figure 6 is a front view of a curing oven with several modules according to the invention; Figure 7 illustrates the internal arrangement of the curing path and the circulation path of the convective residual air. Figure 8 is a view showing the interior of the module of Figure 7 showing the radiant heat panels placed on the side to cure the container; Figure 9 is a side view showing the radiant heat panels in the oven path; FIG. 7 is an elevational view of the module of FIG. 6 showing the side of the thermal panel; lO... Infinite conveyor member, 12... Loading station, 14... Protective coating room, 16... Curing room, 1
8...Discharge station, 20...Feeding conveyor,
22... Moving container, 24... Directional chute, 26.
... Timing screw, 28... 8 sending conveyor, 30... Retracting conveyor, 32... Continuous flight, 34... Container conveyor, 36... Engaging straw inside, 38A... Container holding Apparatus, 40... Inner housing, 42... Outer housing, 44... Roller joint, 46... Head or chuck, 48... Central counting pin, 50...
Cam follower, 52...Cam chamber, 54...Surface, 56
... Internal spring, 58 ... Cam gap, 60 ... Protective coating, 62 ... Nozzle, 64 ... Drive belt, 6
6... Drive wheel, 6B... Glaze, 70... Belt member, 72... Preparation chamber, 74... Pipe, 76...
Water box, 78.80...Rail, 82...Bracket, 84...Sprocket, 86...Painting area, 88
... Pulley, 90... Gear box, 92... Friction rail, 94... Second drive belt, 98.98...
-Pulley, 100...Belt, 104...Third drive belt, 106...Belt being driven, 11O...Upright unit, 112...Left side module, 114...
・Right side module, 116...Middle module, 1
18...Interface, 120...Descent route, 1
22... Ascending vertical path, 124... Descending path, 12
6... Ascending route, 128... Descending route, +30...
- Rising route, 132... Oven exit, 134...
Bottom, 136... Roof panel, 138... Side panel, 140... Elongated opening, 141... Hinge,
142... Access door, 144... Latch, 146...
...Radiant energy source, 14B...Container coating, 150
...Infrared panel, 152...Bracket, 153.
...lower half of the oven path, 154...base of the container,
156... Neck of container, 158... Upper half of channel, 160... Duct, 152... Upright member, 164
... Rear surface, 156 ... Fan or blower, 16
8... Supply header, 170... Discharge header, 172
...Damper, 174...Blowout nozzle.

Claims (25)

[Claims] (1) A method of painting and curing containers having necks and bodies that are to be externally coated with a protective coating, including the step of moving a row of containers to a transfer station and exposing substantially all of the external surface of the body of each container. There is a step in which the neck of the container is gripped by a gripping member, a step in which the container is moved to a painting room and an external protective coating is applied to each container, and a protective coating is applied in order to apply a uniform coating to the entire container. a step of rotating the container in the coating chamber when the coating is applied; a step of rotating the container after the coating is applied to prevent paint dripping and maintain a uniform coating; a step of moving the container to the curing chamber; and curing a container. 2. A method as claimed in claim 1, including the step of: (2) shielding the neck and interior of the container from painting. (3) when the protective coating is applied, including the step of rotating at a faster speed and then rotating at a slower speed to maintain a uniform coating. The method described in section. (4) The method according to claim 3, characterized in that the container is rotated at a high speed of 600 to 1000 revolutions per minute and at a slow speed of 40 to 100 revolutions per minute. 13. The method of claim 12, further comprising the step of: (5) providing a separate path in which the gripping member does not receive a container at the transfer station and does not work through the sprayer. (6) means for moving containers having a common axial direction through a first path at equal distances from each other; and a first carrier having a carrier axially aligned with the containers in time and spacing;
a container carrier having means for moving the container carrier along a second path parallel to the path; and means for gripping the neck of the container and rotating the container about its axis; and moving the container carrier into engagement with the container. means for moving the carriers so that each carrier grips the neck of the container; carrier moving means configured to move the carriers along the path through the painting chamber and the curing chamber; Apparatus for painting and curing a container having a neck and a body, comprising means for rotating the container and means for curing the container. 7. The apparatus of claim 6, wherein the container carrier includes a rotatable hub and means for engaging and rotating the hub within the curing chamber. (8) the rotating means comprises spaced drive belts for rotating the container carrier at a speed of between 600 and 800 revolutions per minute and friction for rotating the container carrier at a speed of between 40 and 100 revolutions per minute; 8. A device according to claim 7, characterized in that it comprises a rail. (9) The device according to claim 6, characterized in that the container gripping means simultaneously shield the neck and interior of the container from painting. (10) The invention further comprises means for moving the container carrier along a non-operating second path through the painting room if the container carrier does not receive a container. The device described. (11) moving the row of containers to a transfer station; a gripping member gripping the open end of each container in such a manner that substantially the entire exterior surface of the container body is exposed; and moving the containers to a coating room. a step of applying an external protective coating to each container; a step of rotating the containers within the painting chamber so that uniform coating is achieved over the entire container when the protective coating is applied; and after the coating has been applied. rotating the container to maintain an even coating without dripping; moving the container to a curing chamber; and subjecting the container to convective and radiation curing to cure the coating; A method of coating a container with an open end with an external protective coating and curing the container, the method comprising: 12. The method of claim 11, further comprising the step of rotating the container during the curing process. (13) moving the container through a curing path, rotating the container as it moves, and alternately applying convective and radiation curing as the container moves through the path; A method of curing a protective coating applied to the external surface of a containing container. (14) The method according to claim 13, characterized in that radiation curing is performed with the arrangement configured to match the shape of one-half of the container. (15) A method according to claim 13, characterized in that convection curing is performed by heated air and radiation curing is performed by an infrared heater panel. 16. The method of claim 15, wherein the curing air temperature is maintained by circulating through the infrared radiation region. (17) The method according to claim 13, further comprising the step of controlling humidity in at least a portion of the curing path. (18) a series of oven modules forming a continuous path through the oven, each module cooperating to form one or more passages with a continuous path, and a convection hardening portion of each passage; means for providing a convective hardening medium; means for forming a radiation hardening portion of each passageway; radiation means; means for arranging thermal radiation along one half of the contour of each container; means for moving and rotating said container through a path. A curing oven for curing containers having an external protective coating. (19) The oven according to claim 18, wherein convection curing and radiation curing are alternately arranged in the path. (20) A patent claim characterized in that the passages are arranged in a vertical tortuous path through the oven, with a convection-curing portion occupying the upper portion of each passage and a radiation-curing portion occupying the lower portion of each passage. The oven according to item 18. 21. The oven of claim 18, including at least two regions along the path having different curing conditions. 22. The oven of claim 21, wherein a separate source of convective hardening medium supplies each zone. (23) The oven according to claim 22, characterized in that one or more regions are humidified. (24) a plurality of radiant panels are adjustably mounted within the oven adjacent the passageway, the panels being in an arrangement generally shaped to the planar contour of the container half; A radiation hardened part characterized by: 25. The radiation curing section of claim 24, wherein each radiant panel is set to operate at a predetermined power through the intervention of a silicon control regulator.