JPS5934494B2 - Expansion method for thermoformable materials - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to techniques for forming or shaping articles suitable for final use from thermoformable materials.

Structural panels are used for many applications. For certain applications, it is desirable that the panel have both stiffness and structural strength and that it also be relatively lightweight. In order to provide such panels, various techniques have been proposed for providing a material having a relatively high density with a core of hard material having a relatively low density. Most of these techniques require the use of specific adhesives to join the low density core to the high density lamina. This adhesive bonding technique has many drawbacks. One such drawback lies in the fact that it is not always possible to find an adhesive that can easily join the two materials that are desired to be in place in this type of laminate.

/)'-X In order to provide adhesives for the different thin layers, it is necessary in some cases to devise relatively expensive adhesives. Moreover, considerable time and effort is involved in using certain adhesives in the manufacture of laminates. For example, many of these adhesives contain solvents. During the manufacture of laminates using such adhesives, it is necessary to allow some time for the solvent to evaporate from the adhesive before actual bonding occurs. This adhesive drying time is
There is a trend toward reducing the use of such solvent-based adhesives in applications that require the use of assembly line techniques in the manufacture of laminates. Additionally, it presents problems with solvent entrapment within the composite structure, which can result in poor physical properties and odor problems. Another point associated with the use of various types of adhesives concerns the use of curable adhesives. These adhesives have a so-called "use life" beyond which the adhesive must be used or lose its usefulness. This shelf life characteristic of adhesives also tends to reduce the use of such adhesives for certain applications. Also, or
The use of such adhesives results in economic losses resulting from the loss of adhesive that cannot be properly used during the adhesive's useful life. U.S. Pat. No. 2,962,409 and U.S. Pat. No. 3,367,760 disclose methods of making laminates without the use of adhesives, but the laminates thus produced have relatively little utility.

This is because only relatively simple core shapes can be manufactured using the method disclosed in the X patent. Molded articles made from thermoformable materials and expanded to provide relatively lightweight core densities, yet having a variety of shapes and good physical properties, are produced by applying reduced pressure within the cross-section of the thermoformable materials. or more voids are formed, and at the same time,
The voids are formed during cross-sectional expansion of the material so that the pressure within the voids equilibrates with the pressure external to the thermoformable material, thereby controlling the uniformity and integrity of the cross-sectional geometry obtained in the expanded material. It can be manufactured in a relatively easy manner by aerating.

It is an object of the invention to provide a product made of thermoformable material and having an expanded cross section.

Another object of the invention is to provide rigid structural elements having a variety of lightweight core structures or geometries.

Another object of the invention is to provide a method by which lightweight expanded articles can be easily formed from thermoformable materials using assembly line techniques without the use of adhesives.

Another object of the invention is to have regularly shaped voids of various sizes and shapes, yet with relatively large areas having discontinuous and/or continuous surface areas as an integral feature of the inflatable structure. An object of the present invention is to form an expandable structure with improved rigidity without the use of adhesives.

Yet another object of the invention is an inflatable structure having a hole in the face of the structure, the hole having a relatively thin lip around its periphery and the lip cutting into the hole a structural feature. and forming an inflatable structure according to the present invention.

Still another object of the present invention is to provide a flexible or rigid intumescent structure having a relatively large number of voids without the use of blowing agents.

The following definitions apply to the description of the present invention.

"Thermoformable" means that the described material is
means that it is a solid and can be reshaped or re-deformed at a slightly higher temperature or higher.

"Thermoplastic" means that the material thereby described is
It means that it is a solid and that it softens or flows to a measurable degree at a slightly higher temperature or higher.

"Thermoset" means that the described material is
means that it is solid and does not soften or flow or can be reshaped at any elevated temperature.

"Crystalline" means that the polymeric material thereby described is
at least 50% of the polymer structure when subjected to linear analysis
This means that it shows a distinct X-ray pattern.

[Amorphous] means that the polymeric material thereby described is
It means that more than 50% of the polymer structure has no distinct X-ray pattern when subjected to radiographic analysis.

"Ta" is the temperature at which the thermoplastic material exhibits hot adhesion.

[Tm], with respect to crystalline polymers, means the melting point of the polymer.

"Tg", with respect to an amorphous polymer, means the temperature at which the polymer changes from a brittle state to a rubbery state.

For crystalline polymers, it is the temperature at which the polymer becomes glassy or loses crystallinity. "Plastic" means a natural or synthetic resin.

"Normal solid" means solid at 25°C.

[Wetting] or "wetting" refers to the relative ability of one material to reach interfacial contact with another material.

"Hot adhesion (force)" means that a material has its Tm or Tg
Refers to the ability of one material to exhibit adhesion to another material when in the molten state at a higher temperature. [Melting point] is the temperature at which a substance softens or melts.

By "cohesive flow properties" is meant the property of a material in its molten state that is readily altered by external forces such that the geometrical cross-sectional area of such material substantially changes under such external forces.

"Thermal Deformation Point" means the temperature of a material as measured by ASTM D-648.

Most thermoformable materials have Ta, the temperature at which they exhibit hot adhesion to other materials. In the case of crystalline polymeric materials, this Ta appears approximately 5-10° C. higher than the Tm of such polymeric materials. In the case of amorphous materials, Ta varies considerably depending on the structure and molecular weight of the material.

Therefore, for amorphous polymers Ta may be about 30-150°C higher than the Tg of such polymers.
Tm or Tg also varies for a given polymer backbone depending on the molecular weight and density of the polymer.

Below, various polymeric materials that can be used in the present invention are listed, along with their Tm or Tg and Ta in °C.

Herein, in the present invention, expansion of a cross-section of a blank of thermoformable material is performed by expanding the cross-section while forming one or more voids of reduced pressure within the expanding cross-section of the blank. and, during expansion of such cross-section, the void so as to equilibrate the pressure within the void with the pressure external to the material, thereby regulating the uniformity and integrity of the resulting cross-sectional geometry of the expanded material. It has been found that by aeration, it can be easily expanded to provide a variety of final products with a variety of expanded cross-sectional shapes.

Expansion of the material is carried out while heating the material to bring it into a thermoformable state, ie, heating the material to a temperature above the melting point of the thermoformable material. The thermoformable material is expanded between a pair of separable forming plates and the plates are spaced apart to produce the desired expansion of the thermoformable material mass while the material is expanded during the expansion operation. It is attached to the surface of the molded plate by some method as described below. Preferred embodiments of the method of the present invention provide that various materials, particularly thermoplastic polymeric materials, can be heated to virtually any substrate at Ta, which is typically higher than the Tg or Tm of such thermoplastic polymeric materials. This is based on the property of exhibiting interstitial adhesion.

Thus, in the molten or molten state, the thermoplastic polymeric material wets substantially all substrate surfaces, thereby imparting tack to it. In some cases, this sticking phenomenon is lost when the thermoplastic polymeric material cools below its Tm or Tg. Therefore, a raw material of thermoplastic polymer material is placed between two molding plates of a heated press, and the temperature of the molding plate is adjusted to about 5 to 1 below the Ta of the polymeric material in the raw material.
0° C. above, and if the plates are mechanically separated, the adhesion of the polymeric material to the plate surface during the plate separation or expansion process will be greater than the cohesive flow properties of the polymeric material itself. It's also big.

As a result, with the polymeric material bonded to the plate surface, it is possible to mechanically separate the plate a distance without causing a break in the adhesion between that surface and the molten material. . Although the mass of the expanded meltable material does not change, the cross-sectional shape of the meltable material changes in the direction of the two spaced forming plates as a result of the suction adhesion between the molten thermoformable material and the forming plate surfaces. Expanded.

The extent to which the cross-sectional area of the molten material can be so expanded is
It is primarily determined by the strength of the adhesive bond between the molten material and the plate surface as well as the extensibility of the thermoplastic resin in the material in the molten state. The stronger such adhesive bonds are, the greater the amount of cohesive flow that can be induced in the molten resin without rupturing the adhesive bonds. The resulting strength, therefore, depends on the nature of the thermoplastic in the stock, the properties of the plate material, the extent of the surface area of the plate in contact with the molten stock, and the cohesive strength and flow properties of the polymer plastic. . Therefore, the use of a material that is easily wetted by the molten plastic material as the mold surface will result in less condensation of the molten plastic than the use of a mold surface made of a material that is not easily wetted by the molten material. This allows for wide spacing of the mold surfaces in a closed state.

Also, the use of the stock in the form of a continuous sheet material allows more surface area of the face of the forming plate to be wetted by the material, thus creating greater adhesion between the molten stock and the forming plate. As the heated thermoformable material is bonded to the forming plate and the forming plate is pulled apart, a reduced pressure void is formed within the expanding plastic body.

The mass of the plastic therefore remains unchanged, but the expanded cross section of the plastic increases. The frequency of occurrence of these voids as well as their size and shape, i.e. the pattern of voids, is determined to a large extent by the pattern of contact points or areas that exist between the mold surface and the expanding plastic during the expansion process. Ru. In order to maintain the desired pattern of voids, it is necessary to vent the voids during the expansion process so that the pressure within the voids equalizes the pressure outside the expanding material. The pattern of contact points or areas between the mold surface and the thermoplastic material can be easily varied.

For example, when the contact surfaces of the forming plate and/or the blank are placed face-to-face, only the convex surfaces of the forming plate and the blank actually touch each other. It can be provided with various designs of recessed or raised surfaces for contacting the surface. Another method of providing a pattern of contact points or sections is to use shaped plates and blanks in which the contact surfaces are in the form of a mesh, grid or reticulation. Therefore, the mesh,
Only grid or reticulated strands are available for contact. Open areas in the mesh, grid or reticular configuration will not provide surface contact between the forming plate and the blank. These various surface designs on the molded plate and/or the material were able to provide at least some contact area between the molded plate surface and the material surface. For example, if the material is in the form of a sheet of material with a smooth, flat contact surface, the slight contact area between the material surface and the forming plate is only a raised surface area for contact with the material surface. This could be provided by using a molded plate with a raised contact surface designed to provide a contact surface or by using a molded plate with a mesh-shaped contact surface. Conversely, if the forming plate has a flat, smooth surface, the blank can be provided with the same selective protrusions or mesh surfaces that provide the desired pattern of contact surface area. The desired pattern of contact portions can also be applied to the contact surface of the molded plate and/or the blank in other manners.

The negative of the desired pattern is created by the use of masking means such as masking tape, kraft paper, strips or panels of 17 Mylar film or other materials that prevent the molten thermoplastic material from adhering to the surface of the molded plate. It can be applied to the contact surface of the raw material or molded plate. Thus, only the molten plastic is deposited on the surface of the forming plate in the contact areas between the forming plate surface and the blank surface, where no masking means are present. In other embodiments of the method of the present invention, the entire surface area of the contact surfaces between the blanks and both mold plates can be used to provide the desired degree of contact area between the contact surfaces of the blanks and the blanks.

It can thus be said that the cross-sectional dimensions of the expandable material are a function of the design of the contact areas provided on the contact surfaces of the forming plate and/or the material.

The design determines the extent to which the surface area of the forming plate and blank are maintained in contact during the expansion step of the method, and the extent of the contact area is the extent to which the expanding material This determines the pattern of voids in the cross-sectional shape. The voids formed in the material during the expansion process can be vented through one or both of the forming plates or by the use of venting means inserted into the material being expanded, or by the use of negative hole means. In some cases, voids or cells are vented from outside the material and between the negative and the molding plate. Venting of the negative hole means can also be achieved by providing a vent hole above the negative hole means and allowing the vent hole to vent to the atmosphere through the molded plate. The rate at which the plates are separated during expansion of the blank is not critical.

The speed that should be used is governed by the cohesive flow properties of the thermoplastic material used in the melt mass. The thickness of the material is about 4
When used in the form of a sheet of about 0 to 300 mil,
The material may be expanded to 2 to 30 times its thickness in accordance with the present invention by expanding the molten material at a separation rate of about 10 to 150 mils/second. After the desired separation distance is achieved, the expanded mass is cooled to a temperature below the thermal deformation point of the plastic, the press is opened, and the expanded mass is removed therefrom. In this respect, the intumescent material can be
It may or may not continue to adhere to the surface of the shaped plate. The expanded material is cooled to a temperature below its thermal deformation point before being removed from the press so as to harden the shape of the expanded material and thus prevent any deformation of the shape.

Thus, in a preferred embodiment of the method of the invention, the cross-section of the blank of thermoformable material having Ta is formed between a pair of forming plates so as to provide a product with an expanded cross-sectional geometry in the next step sequence. expanded between.

That is, a thermoformable material is placed between the surfaces of a pair of molded plates, and the material is heated to a temperature above its Ta; the thus heated thermoformable material is then bonded to the molded plates by hot adhesion. adhesively bonded to each surface of the molded plate; the molded plate is then expanded by expanding a cross-section of the thermoformable material while the heated thermoformable material is adhesively bonded to the surface of the molded plate; 1 of the reduced pressure within the thermoformable material
spaced apart to create one or more voids; and cooling the expanded thermoformable material to a temperature below the thermal deformation point of the material.

Form plates that are not to be removed from the cooled expanded thermoformable material should be removable from the equipment used to space them apart during the expansion step in the above method.

It is also possible to permanently fix one or both of the forming plates to such an apparatus, in which case the cooled expanded thermoformable material is then removed from the apparatus and the forming plates are fixed thereto. Ru. When cooling the expanding material below its Ta or below its Tm and/or Tg,
It does not necessarily automatically lose its adhesion to the surface of the molded plate in all cases.

Intumescent materials made from non-polar materials such as polyolefin resins can be used in the method of the present invention and generally facilitate their adhesion to the surfaces of molded plates of all types described in detail below. lose to. Polar materials, i.e. materials consisting of compounds with an electric moment, such as polysulfone resins and resins containing carboxyl, hydroxyl and ester groups, account for most (if not all) of the molded plates that can be used in the process of the invention. It tends to become X while bound to the surface. however,
Even if the adhesion between the expanded material and the forming plate is not automatically lost upon cooling of the expanded material, the cooled expanded material may destroy the integrity or shape of the expanded material if desired. It can be mechanically peeled off from the molded plate without any problems. The tendency of expanded materials made of both polar and non-polar materials to subsequently adhere to the forming plate after cooling below its thermal deformation point is reduced by the use of forming plates with rough contact surfaces. can be improved by The rougher the contact surface, the better the adhesive bond with the cooled plastic. In addition to the use of hot adhesion, other means for securing the thermoformable material to the forming plate during cross-sectional expansion of the thermoformable material can be used.

In one such other operation, a thermoformable material may be bulked with magnetization-sensitive iron powder and a filler such as barium ferrite, and the filled thermoformable material is thus formed into a molded plate. A desired pattern of contact points or areas can be fixed to the molded plate during the expansion process by applying a magnetic field to selected portions of the contact surface of the molded plate.

The thermoformable material may also be affixed to the surface of the forming plate during the expansion process by applying a static electric power between the expanding thermoformable material and selected contact points on the surface of the forming plate. I can do it. Regardless of the means used to fix the thermoformable material to the forming plate during the expansion process, the thermoformable material
During the expansion step it must be melted or heated to a molten state. The method of the present invention will be better understood from the method sequence illustrated in Figures 1-5 of the accompanying drawings.

FIG. 1 shows a top view of one type of shaped plate 1 that can be used in the method of the invention. The forming plate 1 is a stretched steel mesh with a diamond-shaped metal pattern. The pattern of the steel mesh need not be diamond-shaped; of course it may have other mesh shapes. In contact with the plastic material is the surface of the metal mesh which provides a molded contact surface. Figures 2-4 show the sequence of steps involved in using the shaped plate 1 according to one variant of the method of the invention. Figure 2 shows raw material 2 of a thermoformable material containing Ta.
is shown in the form of a sheet with a smooth surface, which is attached to the open platens 3a' and 3 of the cover press.
It is located between b. Press platens 3a and 3
A mesh metal forming plate is attached to each surface of b. In the illustrated embodiment, the contact points or areas of the upper forming plate 1a are not orthogonally aligned with the contact points or areas of the lower forming plate 1b. In other embodiments, such upper and lower contact points or regions can be vertically aligned. For purposes of the present invention, the formed plate 1 has a Ta of about 5
Heated to ~10°C higher temperature. The forming plates can preferably be heated before or after the blanks are placed in the press, and they are preferably heated conductively via the platens 3a and 3b. The cover press described herein has a movable 6 x 61n with respect to a fixed platen 3b.
This is a 20 ton manual hydraulic ram 3c that operates the platen 3a.

The platen is typically heated electrically. Although a cover press is the preferred means for contacting the heated forming plate with the stock according to the present invention, other suitable devices such as heated belts may be used. The method of the invention can be carried out continuously or discontinuously.

Using equipment such as a cover press, the method is easily carried out discontinuously. Figure 3 shows the press being closed with sufficient pressure so that the upper and lower forming plates exert a slight pressure on the blank 2 so that the heated blank moistens the surfaces of forming plates 1a and 1b in contact with the blank. Shows the state after The amount of pressure required in this step is on the order of about 10z to 41b per 11n2. This pressure causes the material to compress slightly. FIG. 4 shows the platens separated after the expansion process, in which case the expansion material 21 is removed from the forming plates 1a and 1b.
is attached to the point or area of contact with the

During the expansion process, an area of reduced pressure or cells 4 is created within the cross-section of the material being expanded, as will be explained in more detail below.

The side walls of the individual cells 4 are formed by rib portions 7a of expandable material. The area of the cell 4 is formed by the contact point or area of the forming plates 1a and 1b and the side wall 2''a. This is caused by the fact that each cell 4 tends to become a sealed chamber when deposited, and when the molding surfaces are pulled apart the sealed chamber 4 is enlarged to form a depressurized area. In order to prevent pressure from destroying or rupturing the inflation walls 7a of the material, the cells 4 of the material are vented during the inflation process so as to balance the pressure within such cells 4 with the ambient pressure outside the material. This venting tends to preserve the pattern and integrity of the cross-sectional geometry of the resulting expanded material. In this embodiment of the invention, venting is carried out through the cross-sectional geometry of the forming plate and the platens 3a and 3b. Molded plates 1a and 1
This is achieved by an incomplete seal existing between the surfaces of b. After the platens have been extended the desired distance, they are cooled to a temperature below the thermal distortion point of the raw plastic.

Cooling can be produced in the ambient air or by circulating a cooling medium through the platen or by the use of a cooled platen or a combination of such operations. The forming plate is placed in the base of the press so that the previously used set of forming plates containing the expanded material can be cooled while another set of forming plates can be placed in the press along with other materials of thermoformable material. It may be something that can be easily removed from the Also, if the nature of the fusible material and the forming plate is such that the cooled expanding material remains attached to one or both of the forming plates, the forming plate should be able to be removed from the base of the press. . In the latter case, the laminate can be easily formed using the removable molded plate as the surface layer and the expandable material as the center layer. When such a laminate is desired, the laminate may be of the same kind or of different types, or of the same kind to form a laminate in which only one of the removable forming plates remains attached to the cooled expanding material. Alternatively, different types of molded plates can be used. FIG. 5 shows a cooled laminate structure 5 produced as described above with respect to FIGS. 1-4.

The cooled expanded plastic 2' remains bonded to plates 1a and 1b to form a rigid composite structural member 5. The rib portion 7a tends to have an I-beam configuration with a flange portion 2'b in the contact area with the plates 1a and 1b. The expanded laminated structure 5 can be used as it is as a relatively lightweight structure, and the expanded core member 2'' itself can be used as a structural member without being used together with the metal plates 1a and 1b. For artistic or other purposes, it may be desirable to expand the cross-section of the material in a non-uniform manner so as to provide expanded material with cross-sectional areas of varying thicknesses.

FIG. 6 shows another type of removable forming plate 6 that can be used in the method of the invention, and FIG.
This shows an expandable material 8 that can be manufactured using.

A shaped plate 6, as shown in FIG. 6, is a metal sheet in which a pattern of holes is formed and a pattern of ridges 7 is left on the surface of the pattern. If the forming plate 6 is formed with holes therethrough, either side of the forming plate can be used to contact the fused plastic material in the method of the present invention. In manufacturing the inflatable material 8 shown in FIG.
As shown in the figure, one removable forming plate 6 is used in the cover press instead of the upper metal plate 1.
The forming plate 6 is mechanically fixed to the upper platen 3a of the press. In this variant of the invention, the flat surface of the lower platen 3b of the press serves as the lower forming plate. In manufacturing the expandable material 8, the upper molding plate 6 is formed by melting the fused material 2 into the molding plate 6.
is contacted with the molten material 2 so as to moisten the surface of the raised portion 7 and the flat surface of the lower platen 3b and adhere thereto by hot adhesive force. Then, when the platens 3a and 3b of the press are opened during the expansion step, the lower contact surface of the blank remains attached to the continuous surface of the lower platen 3b, during which time the blank is formed at the point of contact with the ridge 7. It is attached to the plate 6 and expanded. During the expansion process, voids are formed in the expanded material adjacent to the holes in the surface of the forming plate 6. These voids result in the formation of concave areas or cells 9 in the expandable material 8;
They are then bounded by extensible ribs 10 of inflatable material. The cells 9 are formed on a molded plate 6 so as to maintain the uniformity and integrity of the cross-sectional shape of the resulting expanded material.
Ventilation is provided during the expansion process through holes in the surface of the platen 3a and between the surface of the platen 3a and the forming plate 6. The expanded material 8 can be removed from the press and forming plate 6 upon cooling below its thermal deformation point. Thus, the inflatable material 8 has flat sides 1
1 and an inflatable side 12. The expansion ridges 10 of the expansion material 8 form a mirror image of the ridges 7 on the surface of the forming plate 6.
As shown in FIG. 8, each of these expansion ridges 10 tends to have a beam shape. This I-beam shape is common for most (if not all) of the expansion ribs found in all of the expanded product variations formed by the method of the present invention. In a variant of the invention shown in FIGS. 6-8, the ridges 10 of the inflatable material 8 are inflated a relatively short distance so as to form some kind of embossed surface on the upper surface 12 of the inflatable material 8. .

This acupuncture sink is not a true acupuncture sink. This is because the upper surface of the ridge 10 is cut by the I-beam shape of the ridge 10, as shown in FIG.
This acupuncture sink effect can be used for the decoration of plastic sheets intended for decorative purposes or for cement mortar, gypsum plaster or insulating bituminous cork mastic by the incised features of the flanged upper surface of the ridge 10. It can be used as a means for mechanically bonding or fixing other substrates or substances such as. The ridges 10 of the expandable material 8 are further expanded by further pulling the molded plates apart.

The height to which ridge 10 can extend depends on several factors.

Generally speaking, the height of the ridges 10 is increased by increasing the surface area of the upper surface of the ridges 10 (this is actually the contact of the ridges 7 of the forming plate 6 shown in FIG. 6). (by increasing the surface area of the surface). Thus, the ridges 7, which have a large surface area, contact more of the surface of the material to be expanded, and thus it ensures that more of the plastic of the material is pulled into the shape of the ridges 10 during the expansion process. Allow. 9th
Figures 1 to 13 include further embodiments of the method of the present invention.

FIG. 9 shows a side view and FIG. 10 shows a top view of a blank 13 made from two plastic sheets and a network of multi-strand fibers 14. Material 1
3 is manufactured by fusing a network of fibers 14 between two plastic sheets. Fiber network 14
extends to the outside of the material 13. 11-13 show the blank 13 at expansion 13''.
Car halfless platens 3a and 3b shown in Figure 4
Material 13'' after being expanded according to the method of the present invention by hot adhesion between a pair of molded plates having smooth surfaces such as
shows a top view.

Figures 12 and 13 show the expansion material 13! 12-12 and 13-13, respectively. 1st
1-13 show that the intumescent material 13' has a fairly regular repeating pattern of relatively thin-walled I-beam ribs 15 and relatively large voids 16. The voids 16 follow the pattern of the fiber network 14 and the beams tend to form within rectangular areas bounded by intersecting parallel strands of fibers. Thus, the cross-section of the inflatable material exhibits a continuous void pattern and a discontinuous rib pattern that follows the pattern of the net 14. When viewed from the top of the inflatable material 1, the ribs 15 tend to have an X-shape within each rectangular area bounded by intersecting parallel strands of the mesh 14. The pattern of voids is created by aeration of the expanded material through the multi-strand fiber network 14 during the expansion step in the method of the invention. The fiber mesh 14 may be any made from any multi-strand fibers, including inorganic and organic fibers such as glass fibers and cotton fibers, to aerate the expanding material. Other ventilation means such as perforated pipes or tubes or porous rods can be used.

The ventilation means can be removed from the inflatable material or left in it depending on the end use. The ventilation means used in this embodiment is not limited to having a lattice shape as shown for mesh 14. Other shapes can be used. 14-16 disclose yet another type of inflatable material 17.

The expandable material 17 shown in FIGS. 14-16 is manufactured from a solid sheet of thermoplastic resin having Ta. The sheet is expanded by hot adhesion as described above between a pair of smooth platens, such as car halfless platens 3a and 3b. The voids created in the expanding plastic are caused by the side 19 of the expanding material being removed during the expansion step of the process.
It is ventilated through. This venting scheme creates a random pattern of voids 18 and I-beam ribs 20 in the expanded cross section. Thus, FIG. 14 shows the gap 18 and the rib portion 20.
15 and 16 show cross-sectional side views along lines 15-15 and 1616, respectively. Rib part 2
Because of the random presence of 0, the inflatable material 17 has the same thickness and is made of the same plastic as the inflatable material 13' as shown in FIGS. (having a regular pattern of sections) do not have as much structural strength and therefore are not as useful for load-bearing purposes. However, the expansion material 1
7 has application as a lightweight inflatable structural member that can be used for packaging purposes, ie as a relatively inexpensive cushioning member. 17 and 18 disclose yet another type of inflatable material 21. FIG.

Figure 17 shows the blank after expansion but before the forming plate is removed, and Figure 18 shows the expanded blank after the forming plate has been removed. Expandable material 21 shown in Figures 17 and 18
is manufactured from a solid sheet of plastic with Ta. The sheet is expanded by hot adhesion between a pair of molded plates as previously described. The molded plate 22 is the same stretched metal sheet as the metal mesh sheet 1 shown in FIG.

The lower molding plate 23 is a lower platen having a car half-less smooth surface. The resulting voids 24 in the expanding plastic are vented through holes in the face of the forming plate 22 during the expansion step of the process. The resulting expandable material 21 has an upper surface 26 that reproduces a mesh pattern at the interface between the forming plate 22 and the plastic material, and a flat lower surface 25 that is smooth and continuous. The rib portion 27 of the expandable material has an I-beam shape. In most cases, the air gap 24 and the air gap 24
The rib portions 27 forming a common wall between them maintain their uniformity and integrity during the expansion process and are not punctured. Figures 19 and 20 disclose other types of expandable material 28 that can be formed with other variations of the method of the present invention. The expandable material 28 shown in FIGS. 19 and 20 is made of Ta
17, by expanding a sheet of plastic with the aid of hot adhesion as described above between two stretched mesh molded plates of a platen 22 of the type shown in FIG. In this embodiment of the method of the invention, the sides of the forming plate to be brought into contact with the plastic are placed in the press in such a way that one side is, as it were, at right angles to the other side. Thus, the diamond-shaped pattern on the upper forming plate is
90 revolutions are made with respect to the diamond-shaped pattern of the lower forming plate. Figure 19 shows the expanding material 28 after removing the forming plate.
and FIG. 20 shows a cross-section of the inflatable material 28. The upper surface 29 of the intumescent material 28 shows a reproduction of the mesh-faced forming plate deposited during the inflating process. The cavity 30 is open at the top surface 29 and closed at its sides 31 and bottom 32. A closed bottom 32 of the cavity 30 is formed by a lower surface 33 of a continuous mesh of inflatable material. Similarly, the void 34 is open at the underside 33 of the inflatable material and at its sides 31 and apex or apex 35.
It is closed in The closed top of the cavity 34 is formed by the upper surface 29 of the continuous mesh of inflatable material. The sides or ribs 31 of the voids or cells 30 and 34 have essentially a one-beam shape. Each rib portion 31 forms part of the sides of both cell 30 and cell 34 . During the expansion step in the process, the resulting voids 30 and 34 are vented by openings in the upper and lower mesh platens, respectively.

Figures 21 and 22 show another type of expandable material 3G that can be formed by yet another variation of the method of the invention.

The intumescent material shown in Figures 21 and 22 is made from a solid sheet of plastic with Ta. The sheet is
As described above, the material is expanded by hot adhesion between the pair of molded plates. Each of the platens is a steel sheet in which a series of regularly spaced holes are drilled.
In each case, holes are provided through the molded plate.
The holes are the same size in each of the molded plates, and they are spaced and aligned in the same pattern in each molded plate so that each plate is actually a copy of the other. When installed in the car half plate as top and bottom platens, the two platens are positioned so that each of the holes in the top plate is positioned directly over and perfectly aligned with the holes in the bottom plate. FIG. 21 shows a top view of the inflatable material 36. The upper surface 37 of the expansion material 36 provides a facsimile of the perforated surface of the upper forming plate of the press that was deposited during the expansion process. FIG. 22 shows a cross-section of the inflatable material 36. The inflatable material 36 provides a series of irregularly shaped spaced cavities or cells 38 that are open at the top and bottom. Each cell is separated by I-beam shaped ribs 39 along its sides. The top and bottom portions of the rib portion 39 provide a continuation of the perforated top portion 37 and bottom portion 40 of the inflatable material. During the expansion step in the method, the resulting cells 38 are vented to ambient pressure through the holes in the mold plate and the interface between the mold plate and the platen. Figures 23-25 disclose the manufacture of other types of intumescent materials that can be formed with yet other variations of the method of the present invention.

FIG. 23 shows the top 21 of the plastic sheet on which a pattern of adhesive tape strips 22 or other temporary masking means, such as a removable screen covering layer having the desired masking pattern, has been placed. The temporary masking means is removed before expansion of the blank 21, and the pattern of the masking means is designed to form a pattern on the surface of the blank to be expanded. After the temporary masking means are in place, the primary masking material is applied to the parts of the surface of the blank 21 not occupied by the temporary masking means. The primary masking means may be a fine coating of talc or clay or any other substance that prevents hot sticking between the stock and the platen of the press.

The primary masking means are left on the material during the expansion process;
It is thus used to provide a pattern of areas on the surface of the material that is not expanded during the expansion process. After the primary masking means is in place, the temporary masking means are removed prior to expansion of the blank in the press. FIG. 24 shows a cross section of a plastic sheet 21 with a strip pattern of temporary masking means 22 and primary masking means 23 on both sides. Removing the temporary masking means from the blank 21 and expanding it between the platens on the continuous side of the press according to the method of the present invention results in an expanded product 24 as shown in FIG. The expanded product 24 has an I-beam shape and has elongated ribs 25 expanded above the area previously occupied by the temporary masking means 22 . The strips of the main masking means 23 are still in place, but these can be left in place or removed. During the expansion process, the rib portion 25 and the rib portion 25
The air gap obtained in the form of a groove 26 between is vented to the outside of the inflatable material through its ends. In this embodiment of the inflatable material, the ribs 25 on the top and bottom surfaces of the inflatable material are all parallel to each other with a thin continuous membrane or film 27 between them. Inflatable materials of this type can be manufactured, in which case the pattern of the inflatable rib membrane is determined simply by applying suitably designed primary masking means to the side of the material which is to be provided with the desired pattern of inflatable ribs. It can possibly be formed on either or both sides of the plastic material. If the desired pattern of inflatable ribs in this inflatable material variation is such as to prevent adequate ventilation of the voids formed through both sides of the inflatable material during the inflation process, then By using a porous molded plate for this purpose, provision can be made for venting the voids through the surface of the molded plate. 26th
and 27 show, for example, this type of expandable material,
The expandable material has a plurality of mushroom-shaped or I-beam-shaped expandable materials 28 protruding from one side of a plastic sheet 29 and can be manufactured as disclosed in Example 21 below. FIG. 26 shows a top view of the inflatable material, and FIG. 27 shows a cross-sectional view of the same inflatable material. Figures 28 and 29 illustrate other types of expandable materials that can be formed with other variations of the method of the invention. Second
The intumescent material 31 shown in Figures 8 and 29 is made from a solid sheet of Ta-bearing plastic. The sheet is
As described above, the material is expanded by hot adhesion between the pair of molded plates. The lower forming plate is a continuous surface of the lower platen of the car halfless. The upper forming plate is a steel sheet with a series of regularly spaced holes drilled into it. The hole can have an arcuate side and/or a vertical side. The holes in the upper molding plate used to manufacture the expandable material 31 are all circular. The molded plate with holes used was No. 40 below.
~ It has the shape shown in Figure 41. Each of the holes defines a circular hole of the same size. Figure 28 shows expansion material 3
1 is shown in a perspective view, showing that the inflatable material 31 is a multicellular container. Container 31 has a continuous smooth base 32 and a continuous outer wall 33 .

Each of the cells 34 of the container is thus open at its top and closed by the base 32 at its bottom. Each of the cells is also closed on the sides and separated from each other by the inner wall 35 alone or in combination with the outer wall 33. Inner wall 35 and outer wall 3
3 has an I-beam shape. Cells whose walls are all internal are symmetrical and hexagonal in shape. These can be referred to as internal cells. Cells that have both an inner wall and an outer wall can be referred to as outer cells and these are not symmetrical in shape. The difference in cell shape is caused by the shape and spacing of the holes in the upper platen. The top 36 of the inflatable mass 31 provides a replica of the surface of the perforated top plate used to form the inflatable mass. Thus, the solid portion of the surface 36 of the expandable material 31 represents the portion of the material that was in contact with the solid portion of the upper forming plate during the expansion step of the method. A hexagonal inner cell is naturally formed when the hole in the upper molding plate is completely circular, even though the lip 37 forms a circular shape that duplicates the hole in the upper molding plate. FIG. 29 shows a top view of the expandable material 31. FIG. The irregular shape of the outer cells is clearly shown in Figure 29 compared to the regular hexagonal shape of the inner cells. Irregularities in the shape of the outer cells result from the need for the expanding cells to conform to the shape of both the holes in the upper forming plate or its outer edges during the expansion step in the method of the invention. The lip portion 37 tends to be flexible so that it can be conveniently placed inside each cell, as shown by the capped bottle 38 placed in one of the cells in FIG. Transport for items such as bottles and/or
Multi-cell containers 31 can be used as row cartons. The hexagonal shape of the inner cells and irregular shape of the outer cells in the expandable mass 31 is primarily due to the fact that the outer rows of holes in the upper molding surface did not receive average hot-agglomerated polymer flow.

This is due to the fact that the position of the inner row of holes in the upper molding plate was staggered with respect to the positioning of the outer row of holes in the upper molding plate. If all the circular holes are aligned as in the platen used and the 21st and 2nd
If a single perforated molded plate is used to form the expandable mass 36 shown in Figure 2, the resulting expandable mass will have square cells regularly aligned with the sealed mass. Thus, variations in hole alignment and spacing result in variations in the shape of the holes, and thus in the shape of the resulting cells. However, even if circular holes are used in the platen, the cells often tend to have angular sidewalls. Expanding material 31 by expanding the plastic sheet
During formation, the cells are vented through holes in the upper forming plate of the press.

Figures 30 and 31 illustrate another type of expandable material 39 that can be formed in yet another variation of the method of the invention.

FIG. 30 shows a top view of an inflatable material 39 having a nest-like structure, and FIG. 31 shows a cross-sectional view thereof. The intumescent material shown in Figures 30 and 31 is made from a solid sheet of plastic with Ta. The sheet is expanded by hot adhesion between a pair of molded plates as shown in FIGS. 35-37 as described above. Each of the molded plates is 1/2 inch thick with a series of regularly spaced and staggered hexagonal cavities machined on one side (the front side).
It is a 21n aluminum sheet. Each cavity is
It has a depth of 1/41n and a diameter of 17/321n. A small ventilation hole is then drilled in the center of each cavity through the other side (back side) of the plate. Each vent hole has a diameter of 3/161n. Thus, the hexagonal cavities are the same size in each of the platens, and they are spaced and aligned in the same pattern on each forming plate such that each forming plate is a duplicate of the other. When inserted into a car half dress as its top and bottom plates, the two plates are positioned such that the holes in the top plate are not perfectly aligned with the holes in the bottom plate. Even if each row of holes in the top plate were aligned vertically with a row of holes in the bottom plate, the top row would be such that each hole in the top plate was approximately 1/3 the area of one hole in the bottom plate. and the second hole is modified in the horizontal direction so that about two-thirds of the area overlaps in the vertical front. Also, other overlapping patterns can be used. FIG. 30 shows a top view of the inflatable material 39.

The soil surface 40 of the expansion material 39 provides a replica of the perforated surface of the top plate of the press that was deposited during the expansion process. The lower surface 41 of the inflatable material is a copy of such upper surface. FIG. 31 shows a cross section of the inflatable material 39. The expandable material 39 has two regularly shaped and spaced apart sets of cells open at one end and sealed at the other end. Each cell is cone-shaped. As shown in FIG. 31, one set 42 of cells 42 is open at the upper surface 40 of the blank 39 and sealed at its lower surface 41, and a second set 43 of cells 43 is open at the lower surface 41 of the material 39. It is open at face 41 and sealed at its upper face 40.

The cells are separated by a single beam rib 44 . The ribs 44 forming each cell condense together at the apex at the base of the cell to form a sealed base. Rib portion 44
The top and base of provide a continuation of the perforated upper surface of the inflatable material 39 and the base 41 . The lip portion 45 present around each cell 42 is not very noticeable. This is because the holes in the plate from which the inflatable material 39 is made are relatively closely spaced and aligned, and the holes are square and not circular or arcuate. The use of circular or arcuate holes in the platen tends to create a noticeable lip around the cell openings in the expandable material, as shown in FIGS. 21, 28 and 29. Deformable or noticeable lips are not necessarily beneficial in expandable materials intended for use as load bearing members. The prominent lips represent resin that is not used to strengthen the ribs 44 as in the inflatable material 39, and this is due to the fact that the intumescent material is not used when such material is used for load-bearing purposes. is a load-bearing element, but increases its bending strength by providing a large area to the discontinuous epithelial element. During the expansion of the plastic sheet to form the expanded material 39, the cells 4
2 and 43 are vented through holes in the upper and lower forming plates of the press, respectively.

Figures 32 and 33 illustrate other types of expandable material 46 that can be formed in yet another variation of the method of the present invention.

The intumescent material shown in Figures 32 and 33 is made from a solid sheet of Ta-bearing plastic. The sheet is
As described above, the material is expanded by hot adhesion between the pair of molding surfaces. The lower forming plate is a continuous surface of the lower platen of the car halfless. This upper forming plate is an aluminum sheet and its contact surface is similar to that of a Watsufuru baking pan. This molded plate is shown in FIG. The contact surface of the upper molding plate thus consists of a series of aligned rows and columns of rectangular metal surfaces, each rectangular being separated from one another by a groove running the length and width of the upper molding plate. . FIG. 32 shows a top view of the expandable material 46 after it has been removed from the press and subjected to further processing steps as described below, and FIG. 33 shows a cross-sectional view thereof. The top view of the expansion material 46 provides a partial reproduction of the pattern of the contact surfaces of the upper forming plate of the press that were deposited during the expansion process, as shown in FIG.
This pattern is shown reproduced in the pattern of columns and rows of rectangular heads 47 shown in the upper half of inflatable material 46 in FIG. Each of these rectangles 47 is the head of an expanded I-beam rib section 48 shown in cross-section in FIG. The base 49 of the inflatable material 46 is a continuous film of plastic that forms the base of each rib 48. During the expansion step in the method, the air gaps obtained in the form of grooves 50 between the expanding ribs 48 are vented out of the sides of the expansion material through their ends. After the expansion operation,
Some of the head portions 4r of the rib portion 48 are connected to the 32nd and 3rd portions.
The bristles 48A are removed as shown in FIG.

The intumescent material 46 shown in Figures 32 and 33 can be used for the manufacture of fuzzy articles such as artificial lawns, brushes, scrapers, and cushioning materials. Head part 47
can be removed from or left on the rib portion 48 for all of these applications. FIG. 34 shows a perspective view of the upper forming plate 51, which is similar to a Watsufuru baking mold and which was used in the method of the present invention to produce the expanded product shown in FIGS. 32-33.

The molded plate 51 has a series of interrelated concave grooves 52 cut into the upper surface of the plate. A raised area 53 on the upper surface of the forming plate 51 is formed by a grid-like pattern of grooves 52, and the elevated area 53 serves as the material contacting surface of the forming plate 51.
Grooves 5, 2 act as groove means. Groove means need not be used in a grid pattern. The groove means is a molded plate 5
It may be a series of parallel grooves running in one direction across one face. In the upper forming plate 51 shown in FIG. 52. FIG. 35 shows a partial top view of another type of forming plate 54 having a series of concave cavities as holes and used as a forming plate in the method of the present invention to form the expanded product shown in FIGS. 30-31. A perspective view is shown, FIG. 36 is a partial view of the back side thereof, and FIG. 37 is a partial cross-sectional view.

Forming plate 54 has a top sheet of metal 55 mounted over a hollow U-shaped frame 56 . Front side 5 of seat 55
7 is machined with a series of regularly spaced and staggered rows of hexagonal holes 58. Hexagonal hole 58
are machined approximately half the depth of the top sheet 55. At the center of the base of each hexagonal hole 58, the remainder of the sheet 55 is drilled with a small circular ventilation hole 59 which passes through the other side (back side) 60 of the sheet 55.
The circular ventilation hole 59 is approximately 1/3 the diameter of the hexagonal hole 58. All hexagonal holes 58 have the same dimensions. Ventilation hole 59
opens through the back side 60 of the seat 55 into a hollow area 61 defined by the tripod 62 of the U-shaped frame 56. The back side 60 of the sheet 55 is provided with grooves 59A for connecting each column of ventilation holes 59 to facilitate ventilation therethrough. Further, a screw hole 63 is provided in the wall of the leg portion 62 for circumferentially surrounding the molded plate 54 in a car halfless manner.
These two molded plates 54 are used as a car half dress as described above to produce the expandable material shown in FIGS. 30-31 and 38-39. Venting the back side of the molded board to the outside of the board is done through the open wall of the U-shaped frame 62. When placed in a car half dress as its top and bottom plates for the manufacture of the expanded product shown in Figures 30-31 and 38-39, the two plates 54 are
two front faces 57 facing each other and a hexagonal hole 58 in the top plate.
is positioned and aligned such that it is not perfectly aligned with the hexagonal hole 58 in the lower plate in a vertical plane.

The hexagonal holes 58 in the top plate are positioned such that each hole in the top plate overlaps two or more of the hexagonal holes in the bottom plate in a vertical plane. FIG. 38 shows a top view of the inflatable material 64.

Expanded product 64 is produced by expanding a sheet of thermoplastic material between a pair of forming plates as shown in FIGS. 35-37. The top surface 65 of the expansion material 64 provides a facsimile of the perforated surface of the top plate of the press that was deposited during the expansion process. The lower surface 66 of the expanding material is a replica of the upper surface 65, which provides a replica of the perforated surface of the lower forming plate of the press to which the material 64 was deposited during the expansion process. Thus, FIG. 38 shows that the alignment and positioning in the press of the two forming plates 54 used to produce the expandable mass 64 is such that each hole 58 in the upper forming plate is aligned with the three adjacent holes 58 in the lower forming plate. It is shown that each horizontal row of holes 58 in the upper mold plate is aligned in a vertical plane with two of the horizontal rows of holes 58 in the lower mold plate in an overlapping manner. Each of the holes 58 in the lower molding plate overlaps to some extent in terms of overlapping surface area.
This is done by first aligning each horizontal row of holes 58 in the upper molding plate with a horizontal row of holes 58 in the lower molding plate and then translating the upper molding plate in its X-axis with respect to the X-axis of the lower molding plate. Each hole 58 has two adjacent holes 58 in the lower molding plate.
and further altering the upper molding plate in its X axis with respect to the Y axis of the lower molding plate so that each hole in the upper molding plate overlaps a portion of three adjacent holes 58 in the lower molding plate, and The latter three holes in the lower molding plate are superimposed in the first modification step.
This can be achieved by including two holes 58. Modification of the two molded plates with respect to each other may be such that one or both of the plates are modified in their X and/or Y axes to achieve the desired overlap of the holes in the two plates.

The order of steps involved in aligning and modifying the molded plates is not critical. This is accomplished prior to placing the blank between the aligned and positioned forming plates. FIG. 39 shows a cross section of the inflatable material 64.

The inflatable material 64 also provides two regularly shaped and spaced sets of cells that are open at one end and sealed at the other end. Each cell is cone-shaped. As shown in FIG. 39, one set of spring cells 67 are open at the upper surface 65 of blank 64 and sealed at its lower surface 66, and a second set of spring cells 68 are open at the lower surface 66. The upper surface 65 of the cap is sealed. Each cell is separated by a single beam rib 69 . The ribs 69 forming each cell are joined together at the bottom of the cell to form a sealed bottom. The top and bottom portions of the rib portions 69 provide continuity of the perforated top surface 65 and bottom portion of the inflatable material 64 . The lip 70 around each cell 64 and 68 is not very noticeable. This is because the holes in the plate from which the inflatable material 64 was made are relatively closely spaced and aligned, and the holes are square and not circular or arcuate. During expansion of the plastic sheet to form expanded material 64, cells 67 and 68 are inserted into holes 58, vent holes 59 and grooves 59A, as well as the open walls of U-shaped frame 62 in upper and lower forming plates 54 of the press. ventilated.

FIG. 40 shows a top view of a perforated forming plate 71 of the type used in the method of the invention for manufacturing the expanded product shown in FIGS. 28-29, and FIG. 41 shows a cross-sectional view thereof. .

The holed molded plate 71 has a series of regularly spaced holes 72.
A thin sheet of material, such as aluminum or steel, that is perforated to provide a pattern of alternating rows and columns of holes. The holes can have either arcuate or vertical sides or both. The holes 72 in the molded plate 71 are all circular. Each of the holes 72 is a circular hole of the same size, and each hole is separated from one another by a continuation 73 in the surface of the forming plate 71. Holes 72 serve as the hole means previously described, and continuous surface 73 of forming plate 71 provides a forming plate contact surface that contacts the blank contact surface during the expansion process. FIG. 42 shows a top view of two forming plates 71 placed one on top of the other.

The positions of the two plates relative to each other in the vertical plane are such that the holes in the two plates are not aligned.

Thus, each of the holes 72A in the upper plate 71A overlaps one or more of the holes in the lower plate 71B in such a vertical plane. This overlapping pattern is caused by the size, shape and spacing (staggering) of the rows and columns of holes in each plate, and the positioning of the plates relative to each other in the vertical plane.
This same overlapping pattern prevails in the horizontal plane if the mutual position of the two forming plates is maintained and they are both placed side by side on one of their thin end sides. FIG. 43 shows a partial top view and FIG. 44 shows a partial cross-sectional view of an intumescent material 74 made by the method of the present invention.

Expandable material 74 is manufactured by expanding a sheet of thermoplastic material between a pair of molded plates of FIGS. 40-41 arranged as shown in FIG. Material 74
is shown after being removed from the press and forming plate. Inflatable material 74 has two regularly shaped and spaced sets of cells open at one end and sealed at the other end. Each cell is conical. As shown in FIGS. 43-44, one set 75 of such cells are open at the upper surface 76 of the blank 74 and sealed at its lower surface 77, and a second set 78 of such cells are opened at the lower surface 77. It opens at 79 and is sealed at its upper surface. The cells are separated by I-beam shaped ribs 79. The ribs 79 forming each cell join together pointedly at the base of the cell to form a sealed base. The top and bottom portions of rib portion 79 provide continuations 80 and 81, respectively, of perforated top surface 76 and bottom portion 77 of expanded product 74. The top surface 76 of the expanded product 74 provides a facsimile of the material contact surface of the upper forming plate 71A that was deposited during the expansion process. Thus, the open end of the upper cell 75 copies the hole 72 of the molding plate 71A,
The continuous portion or region 80 on the top surface of the expandable material 74 then copies the continuous region 73 of the forming plate 71A. In the same manner, the continuous surface 81 of the lower surface 77 of the expandable material 74 is connected to the lower forming plate 71B.
Provide a copy of the material contact surfaces. As seen in FIG. 43, each of the circular open ends of the upper cells 75 overlap in a vertical plane with approximately three of the circular open ends of the lower cells 78 of the inflatable material. Figure 44 shows that the side walls 79 of the cells tend to be circular rather than flat. FIG. 43 shows the lip 82 around the opening of each cell 75, and the fourth
Figure 4 shows lips 82 and 83 at the openings of cells 75 and 78, respectively. FIG. 45 shows a cross-sectional view of blank 84 used in the manufacture of expanded product 88, shown in top view in FIG. 46 and in cross-sectional view in FIG.

The material 84 shown in FIG. 45 consists of two continuous sheets 85 of thermoplastic material having two smooth surfaces placed on top of a second continuous sheet 86 of thermoplastic material. Sheet 86 has a continuous smooth lower surface. sheet 8
The top surface of 6 has a series of V-shaped grooves 87. The groove 87 is
They are parallel to each other and run the length of the sheet 86. Material 84
A masking means, such as powdered clay, is applied to the surface of the V-shaped groove 87 before expansion. The blank 84 with masking means in groove 87 is expanded between two successive smooth-sided platens or forming plates of the car half plate to form expanded blank 88.
form. After the blank 84 is placed in the press, a hot forming plate or platen is used to compress the blank slightly and form the sheet 8
5 is fused to sheet 84 and the composite fused material wets and adheres to the contact surfaces of the forming plate or platen. Their fusion at the interface between sheets 84 and 85 is caused by the masked V-shaped groove 8 of sheet 86.
It is continuous except for the strip at the interface where 8 and 7 are adjacent. The masking means prevents fusion or adhesion of sheets 85 and 86 where such masking means is present. FIG. 46 shows a top view of the expanded product 88 after the expansion step in the method and after removal from the mold, and FIG. 47 shows a cross-sectional view thereof. During the expansion process, the upper surface 89 of the product 88 adheres to the contact surface of the upper forming plate of the press, and the lower surface 90 of the product 88 adheres to the contact surface of the lower forming plate of the press. During the expansion process, cells 91 form in the cross-section of the expanded plastic, which are essentially rectangular and separated from each other by I-beam-shaped walls 92, and these walls 92 and cells 91 are Extend the length of product 88. Cell 91 is vented through its ends during the expansion process. Each cell 91 occurs at the location of each masked V-groove 87. FIG. 48 shows a top view of another type of thin molded plate 93 that can be used in the method of the invention.

The molded plate 93 has a series of holes of three different shapes or sizes drilled therein: a square hole 94, a large circular hole 95, and a small circular hole 96. Square holes 94 have a slightly larger surface area than circular holes 94, which have a larger surface area than circular holes 96. As shown in FIG. 48, all the holes are arranged in aligned columns in one direction, or vertically, and in an alternating arrangement in the other direction, or horizontally. All of the square holes have the same dimensions as do all the large and small circles. Figure 49 is 40~
41 shows a top view of forming plates 93 positioned above forming plates 71 of FIG. 41, where they are arranged in a row configuration that can be used in the method of the invention.

In the alignment of forming plates 71 and 93 shown in Figure 49, forming plate 71 is in a position intended to be used as a lower forming plate, and forming plate 93 is in a position intended to be used as an upper forming plate. The holes 72 in the lower molding plate 71 are formed in the molding plate 9.
All have larger areas than any of the three holes 94, 95, and 96 in No. 3. 2 of each vertical column of holes in the top plate 93
The distance between two adjacent holes varies but is always smaller than the diameter of the hole 72 in the lower molding plate 71, and the distance between the holes 72
all have the same diameter. Each vertical column of holes in the upper molding plate 93 is aligned with a vertical column of holes in the lower molding plate 71, and in the vertical plane the holes 7 of the lower molding plate 71.
2 overlap with two of the holes in the upper molding plate 93. 50th
The figures show a top view of an expandable material 97 formed using aligned forming plates 71 and 93 as shown in FIG. 49, FIG. 51 shows a bottom view thereof, and FIG. 52 shows a cross-sectional view thereof. show.

Thus, the expandable material 97 shown in FIGS. 50-52 is
A pair of molded plates 7 arranged as shown in FIG.
It is produced by expanding a plastic sheet having a Ta between 1 and 93 with the aid of hot bonding as described above. The top surface 98 of the expansion material 97 shows a reproduction of the forming plate 93 to which it was attached during the expansion process. The lower surface 99 of the expandable material 97 shows a reproduction of the forming plate 71 to which it was attached during the expansion process. Gaps 100, 10 in the upper surface 98
1. and 102 are respectively squares shown on surface 98;
It has a large circular opening and a small circular opening, and they are located on the upper surface 9.
8 and closed at its sides 103 and bottom 104. A sealed bottom 104 of the cavities 100, 101 and 102 is defined by a continuation of the lower surface 99. A cavity 105 with a circular opening opens at the face of the blank 97 and is sealed at its sides 103 and tip or top 106. The sealed upper part of the void 105 is the upper surface 9 of the material.
It is formed by 8 consecutive parts. The common sides or ribs 103 of the voids or cells 100, 101 and 102 on the one hand and the cells 105 on the other hand have essentially the shape of one beam. Each rib or wall 103 has a cell 10
5 and one or more of the cells 100, 101, 102. 100 cells each
, 101, 102, and 105 are more conspicuous around the circular periphery of cells 101, 102, and 105 than around the rectangular periphery of cell 100. Cells 100, 101, 102 and 1
05 generally all have the same height, but their volumes are in the order 102〈101 100 105, and the relative dimensions of the volumes of such cells are respectively and 92 relative dimensions.

Cells 100, 101, and 102 tend to be more conical than cell 105, whereas cell 105
0, 101 and 102 tend to be more cylindrical.
However, the closed ends of all these cells tend to be narrower than their open ends. During the expansion step in this method, the resulting voids 100, 101, 102 and 1
05 are holes 94, 95, 9 in the upper molding plate and the lower molding part.
6 and 72, respectively, and through the incomplete sealing that exists between the surface of the forming plate and the surfaces of the upper and lower platens of the press to which the forming plate is fixed during the expansion process. Ru.

As seen in Figure 50, the apertures of the upper cells 100, 101 and 102 are not aligned with the apertures of the lower cell 105 in the vertical plane.

Thus, each of the lower cells 105 is superimposed in a vertical plane by two adjacent cells 100, 101 and/or 102. This overlapping pattern in cell apertures, as seen in FIG. This is a reproduction of the overlapping pattern in the vertical plane. Also, approximately half of all the cells in the material are cells that open at the bottom surface of the expanding material 97, and the remaining cells are cells 1 that open at the top surface of the material 97.
00, 101 and 102. The attached drawing shows a plastic material containing Ta and having two contact surfaces, such as a plastic sheet, made to have a plurality of cells, that is, become multicellular, by expanding the material between a pair of molded plates having appropriate contact surfaces. The method involved in the production of the described expandable material is such that when the forming plate is brought into contact with the material, the contact surface is such that there is at least some distance between the contact surface of the platen and the contact surface of the material. designing one or more of the contact surfaces to be adapted to provide a pattern of contacts, placing a material between the contact surfaces of the forming plate and heating the material to a temperature above the Ta of such material; The molded plate and the material are brought into contact at their contact surfaces, and during this time the material is coated with Ta to cause hot adhesion between the contact surfaces of the material and the molded plate.
Using the material thus adhesively bonded, the distance between the forming plates is expanded to cause expansion of the cross-section of the material, and the materials in the material are separated by expansion ribs. A plurality of cells are concomitantly formed within the expanded cross-section, such cells surrounding the depressurized area, and the shape of each cell and all of its combinations forming between all contact surfaces. during expansion, the cells are aerated to equilibrate the pressure inside the cells with the pressure outside the material, thereby increasing the uniformity and integrity of the cross-sectional geometry. It can be specifically described as a series of steps including maintaining the properties of the expanded material and cooling the expanded material to a temperature below the thermal deformation point of the plastic used to make it.

As previously described, a contact pattern between the platen contact surface and the blank contact surface can be provided on either or both surfaces of the forming plate or on either or both of the blank contact surfaces.

Venting can be accomplished through one or both sides of the platen by using gas permeable porous or perforated molded plates. Expanded plastic articles formed in accordance with the present invention are lightweight panels that can be rigid or flexible depending on the type of plastic used and the extent to which the plastic is expanded.

Additional stiffness can also be provided by bonding the expanded plastic member to one or more rigid thin layers. Expanded plastics can be used as structural elements for containers, walls, partitions, laths, packaging materials and other applications where lightweight construction materials are used, with or without other thin layers bonded thereto. The material that can be used as a raw material in the present invention is about 50 to 300°C, preferably about 10°C.
It is a normally solid thermoformable material with a Tg of 0-250°C. If any 2 can be used as forming plate
If there is a difference of at least about 10°C between the melting points of different meltable materials, the meltable material with a lower melting point can be used as a raw material, whereas the meltable material with a higher melting point can be used as a molded plate. can be used. The material can be used in a variety of forms, such as sheets, nets, and sheets with stamped designs.

The meltable material used for the material does not need to have any elastomeric properties. Meltable materials that can be used as raw materials include natural and synthetic thermoplastics and thermosets, glasses, low melting point elemental metals, and alloys and compounds thereof.

Natural resins include materials such as asphalt, bitumen, gums, pitch and tar.

Synthetic SjJI includes beer resin. These vinyl resins may be homopolymers of individual vinyl monomers, or they may contain from 0 to about 50 monomers and one or more non-vinyl monomers that can be copolymerized therewith. It may be a copolymer with mol%. The term "vinyl monomer" refers to the formula -C
It means a compound containing at least one -C- polymerizable group. Therefore, such vinyl monomers include monoolefins such as ethylene, propylene, 1-butene and isobutylene, unsubstituted olefins such as polyolefins such as butadiene, isoprene, synchropentadiene and norbornene, chloroprene, tetrafluoroethylene, etc. , chlorotrifluoroethylene, halogenated olefins such as hexafluoropropyne, styrene, o
-methoxystyrene, p-methoxystyrene, m-methoxystyrene, o-nitrostyrene, p-nitrostyrene, o-methylstyrene, p-methylstyrene m-methylstyrene, p-phenylstyrene, 0-phenylstyrene, Vinyl aryls such as m-phenylstyrene, vinylnaphthalene and the like, vinyl chloride, vinyl fluoride,
Vinyl halides and vinylidene such as vinylidene chloride, vinylidene fluoride, vinylidene bromide and the like, vinyl formate, vinyl acetate, vinyl propionate, vinyl butyrate,
Vinyl esters such as vinyl chloroacetate, vinyl chloropropionate, vinyl benzoate, vinyl chlorobenzoate, etc., acrylic acid, chloroacrylic acid, methacrylic acid, ethacrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, acrylic acid n-octyl, 2-ethylexyl acrylate, n-decyl acrylate, methyl methacrylate, butyl methacrylate, methyl ethacrylate, ethyl ethacrylate, acrylamide, N-methylacrylamide, N-N-dimethylacrylamide, methacrylamide, N -Methyl methacrylamide, N-N-
Acrylic acid, α-alkylacrylic acid, such as dimethylmethacrylamide, acrylonitrile, chloracrylonitrile, methacrylonitrile, ethacrylonitrile, etc.
Alkyl esters thereof, amides thereof and nitriles thereof, maleic acid and fumaric acid and anhydrides and alkyl esters thereof, such as maleic anhydride, dimethyl maleate, diethyl maleate and the like, vinyl methyl ether, vinyl ether, Vinyl alkyl esters and ketones such as vinyl isobutyl ether, 2-chloroethyl vinyl ether, methyl vinyl ketone, ethyl vinyl ketone, isobutyl vinyl ketone and the like, as well as vinyl pyridine, N-vinyl carbazole, N-vinyl pyrrolidone, ethyl methylene malo Nate,
Acrolein, vinyl alcohol, vinyl acetal,
Includes vinyl butyral and the like. Therefore, vinyl polymers include, for example, polyethylene, polypropylene, ethylene-propylene copolymer, polyvinyl chloride, polyvinylidene chloride, polyvinyl fluoride, polystyrene, styrene-butadiene-acrylonitrile terpolymer, ethylene-acetic acid. Includes vinyl copolymers, ethylene-acrylic acid copolymers, ethylene-acrylonitrile copolymers, and styrene-acrylonitrile copolymers. In addition to vinyl polymers, other polymeric materials that can be used according to the invention are thermoplastic polyurethane polyamide resins, such as nylon resins (including polyhexamethylene adipamide), polysulfone resins, polycarbonate resins, Included are phenoxy resins, polyacetal resins, polyalkylene oxide resins such as polyethylene oxide and polypropylene oxide, polyphenylene oxide resins and cellulose ester resins such as nitrocellulose, cellulose acetate and cellulose propionate.

Also included within the term "polymer" are blends of two or more polymeric materials.

Examples of such blends include polyethylene-polypropylene blends, low-density polyethylene-high-density polyethylene blends, polyethylene and olefin copolymers such as those described above (e.g., ethylene-acrylic acid copolymers, ethylene-ethyl methacrylate copolymers). combination, ethylene-ethyl acrylate copolymer, ethylene monovinyl acetate copolymer,
ethylene-acrylic acid-ethyl acrylate terpolymer,
(e.g., ethylene-vinyl acrylate acetate terpolymer). Also included within the term "polymer" are metal salts of polymers containing free carboxylic acid groups or blends thereof. Examples of such polymers are ethylene-
These include methacrylic acid copolymers, ethylene-ethacrylic acid copolymers, styrene-acrylic acid copolymers, butene-acrylic acid copolymers, and the like. Examples of metals that can be used to provide salts of such carboxylic acid polymers include sodium,
Monovalent, divalent, and trivalent metals such as lithium, potassium, calcium, magnesium, aluminum, barium, zinc, zirconium, beryllium, iron, nickel, and cobalt.

The polymer forming the material can be in any form commonly used in the field of forming, such as powder, pellets, granules, etc.
They can also be used in the form of a blend with one or more auxiliary agents.

Such adjuvant materials include plasticizers, heat and light stabilizers, fillers, pigments, processing aids, extenders, fibrous reinforcements, impact modifiers, and metal, carbon, and glass additives. Includes fibers and particles. The type of polymeric material used will dictate the selection and amount of adjuvants to be used therewith.

This is because there are adjuvants for each of the polymers used in the present invention. The adjuvants used must be physically and chemically compatible with each of the other components of the composition under the operating conditions mentioned above. The adjuvant is
Used in such amount as is effective for the intended purpose. Thus, for example, an effective amount of plasticizer is the "plasticizing dose--that is, the amount of plasticizer that appreciably improves the flexibility, processability, and/or swelling properties of the polymer." Stabilizers are used in stably effective amounts, and fillers are used in effective amounts such that, for example, if reinforcing fillers are used, the fillers are used in amounts that provide the desired reinforcing effect. Ru. The polymeric substrate compositions expanded in this invention may be prepared by any of the techniques commonly used to formulate them.

Such methods include techniques such as dry mixing or hot compounding with or without mixing equipment such as Rippon blenders, Mueller blenders, intensive mixer blenders, extruders, Banbury mixers, etc. includes. Although metallic structural materials are normally used as forming plates in the method of the invention, low-boiling metals or alloys or compounds thereof are made from non-melting materials or have a higher melting point than said low-melting metallic materials. It is also possible to make an expanded material according to the invention when used as a blank together with a molded plate made from the material.

Some rigid polymeric materials, such as polysulfone resins, polycarbonate resins, and certain vinyl resins (eg, polyvinyl chloride), tend to exhibit closed strain when compression molded into blanks.

When such strains are present, the material cannot be readily used in the apparatus of the present invention unless the material is first annealed to relieve such strains in the material. This annealing can be accomplished in about 0.5 to 10 minutes at a temperature between the heat distortion temperature and the melting point of the resin. When the composition used in the thermoformable mass contains fillers, the expansion temperature may have to be increased by 5-20°C to compensate for the increased viscosity of the resulting composition. The two forming plates used in the present invention to separate the blanks can be made from the same or different materials.

Shaped plates may have continuous or perforated surfaces, and they may be porous or non-porous, planar or non-planar, and matched.
During the forming operation, it is desirable to vent the inner portions of the material being separated, as described above.

The need to ventilate the expanding material as mentioned above
This occurs due to the fact that during the expansion operation a vacuum is created in the inner part of the material due to the increase in volume of the inner part of the material. If the material is not vented during the inflation operation, atmospheric pressure will puncture the extended rib portion of the expanded material during the inflation operation. Ventilation of the inflatable material can also be achieved by using perforated or porous molded plates. The materials from which the shaped plates can be made are usually solid materials that are not meltable at the operating temperature or have a melting point at least 10° C. higher than the melting point of the meltable material from which the blank is made. Non-melting materials that can be used for the molded board are wood, paper, cardboard and cellulosic materials such as compressed sawdust, thermoset or vulcanized compositions based on natural or synthetic resins: graphite. , minerals such as clay and quartz; natural rocks and stones such as marble and slate: bricks, tiles,
Building materials such as wallboard and concrete; and protein materials such as leather and rawhide.

Fusible materials with relatively high Tg or Tm that could be used as forming plates include metals such as aluminum, iron, lead, nickel, magnesium, copper, silver and tin, and alloys and compounds of these metals (e.g. copper, brass and bronze); various materials such as glass, ceramics and porcelain; and so-called engineering plastics,
Thermoplastic resins with relatively very high melting points, such as polytetrafluoroethylene, nylon-6 resin, polyacetal resin, polyvinylidene fluoride, polyester and polyvinyl fluoride, or coated with polytetrafluoroethylene Contains meltable materials.

The use of mold release agents, such as silicone oils and fluorocarbon oils, or the use of molded plates made from materials with low surface energy, such as polytetrafluoroethylene, allows the cooled expanded material to It ensures separation of the expanded material from the forming plate if it would not otherwise be easily separated from the forming plate.

As previously mentioned, one or both of the forming plate surfaces used to attach to, pull apart and expand the plastic stock may be part of the platen of the press or forming equipment.

One or both of the forming plates may be removably attached to the platen or forming apparatus. The use of removable shaped plates is preferred if the shaped plates are perforated or porous to provide ventilation, or if laminates are to be formed. For many applications, it may be desirable to promote adhesion of the expandable material to the shaped plate, such as in the formation of laminates.

Certain compounds can be used as adhesion promoters for this type of purpose. These adhesion promoters are used as primers and are applied to the surface of the laminated substrate as a layer that is at least monomolecular in depth. The adhesion promoter may be blended or mixed with the components of the material. In the latter case, the adhesion promoter is approximately 0% based on the weight of the material.
．． It is added to the material in an amount of 00001 to 5.0% by weight.
When an organosilicon compound is used as a primer or incorporated into a substrate, it may be used in organic solvents such as alcohols, esters, ketones, aromatic or aliphatic hydrocarbons, halogenated hydrocarbons, or in combination with such solvents. It can be used in the form of a solution in a mixture.

Examples of organosilicon compounds that can be used include silyl peroxide compounds, alkoxysilanes, aminoalkoxysilanes, vinylalkoxysilanes and aminoalkylalkoxysilanes. Silyl peroxide compounds may be in the form of monomers or polymers, such as silanes or siloxanes. In fact, they contain an organic peroxy group bonded to silicon, the organic part of which is bonded to the peroxy oxygen, and any silicon which is bonded to silicon by a non-carbonyl carbon atom. It may be a containing compound. These silyl peroxides can be made according to the methods described in co-pending U.S. Patent Application No. 9034 (filed February 5, 1970) and No. 34897 (filed May 5, 1970). .

Specific examples of such silyl peroxide compounds are vinyltris(t-butylperoxy)silane, allyltris(t-butylperoxy)silane, tetratris(t-butylperoxy)silane,
t-butylperoxy)silane, allyl(t-butylperoxy)tetrasiloxane, vinylmethylbis(t-
butylperoxy)silane, vinyltris(α・α-dimethylbenzylperoxy)silane, allylmethylbis(t-butylperoxo)silane, methyltris(t-
butylperoxy)silane, dimethylbis(t-butylperoxy)silane, isocyanatopropyltris(t
-butylperoxy)silane and vinyldiacetoxy(
t-butylperoxy)silane.

Aminoalkylalkoxysilanes have the following structure (where X is alkoxy, alloxy or acryloxy, and R
is a divalent alkylene of 3 to 8 carbon atoms with at least 3 consecutive carbon atoms separating the N from the Si, and R')! ．． At least one of R' and R'' is hydrogen, and the remaining R' and R'' are alkyl, HO←CH2CH2Ox+
T--15 (here, X is O or 1), H2NCO-, H
2NCH2CH2 and H2NCH2CH2NHCH2
CH2-).

Examples of such aminoalkyl-alkoxysilanes are:
γ-aminopropyltriethoxysilane, r-aminopropyltrimethoxysilane, bis(β-hydroxymethyl)r-aminopropyltriethoxysilane and N-β
Includes mono(aminoethyl)γ-aminopropyltriethoxysilane.

The following examples merely illustrate the invention and are not intended as limitations on the scope of the invention.

The presses used in these examples were car-halfless equipped with springs such as those shown in Figures 2-4.

Two springs were used in the press, each with one
301b/In, and the spring is adapted to mechanically pull the platens apart as previously described in FIGS. 2-4 at a predetermined speed as regulated by a niddle valve on the hydraulic ram of the press. It was designed to.

The platen of the press was of malleable cast iron and could be inductively cooled as desired by circulating cold water.
Further, the platen of the press could be heated by induction as desired by electrically heating the platens 3a and 3b. The surface temperature of the heated platen was measured using a thermocouple pyrometer. Example 1 The 52 mil thick wrought steel mesh shown in FIG. 1 was mechanically secured to each of the platens of a car half dress.

The diamond-shaped pattern of the mesh is 3/81nX
It had a 11n opening and a 115 mil face width for the flat metal mesh strands. 120 mil thick polyethylene (density of 0.96, melt index of 3, 130~
A 61n x 61n smooth surface sheet with a Tm of 140°C and a Ta of about 135-140°C was coated with a toluene solution of vinyltris(t-butylperoxy)silane, a silyl peroxide adhesion promoter, on both surfaces of the sheet. surface area of 1 in2 after evaporating toluene by
A coating of about 2η of silyl peroxide was obtained per coat.

After heating the mesh platen to a temperature of 185°C, the coated sheet was placed in a press as shown in FIG. The platen of the press was then closed to apply a pressure of 10 psi to the stock (peroxide coated sheet) as shown in FIG. The polymer in the material melted and wetted and adhered to the steel mesh molded plate. Equalize the temperature of the entire press forming plate and platen, and keep the temperature at 135℃
It was lowered to The molded plates were then separated as shown in Figure 4 at a rate of 1000 mils/15 seconds and then heated to about 125°C.
It was cooled to Ventilation of the material took place through the mesh of the forming plate and between the contact surfaces of the platen of the press and the mesh forming plate. The normal contact surfaces of the press platen and the mesh forming plate were sufficiently rough to allow sufficient ventilation therebetween. The expanded sheet was removed from the press with the mesh forming plate still attached to it.

The resulting composite structure had a thickness of 3/41n as shown in FIG. The ribs of the expanded plastic core were regularly spaced and tightly bonded to the mesh molding plate. A hard blow of 150ft/1b was applied to a part of the mesh surface of the composite with a diameter of about 11n, which deformed the mesh molded plate and the expanded core, but caused cracking of the adhesion layer of the expanded core from the mesh molded plate. I didn't wake him up. The resulting laminate was a structural core with two mesh skins suitable for automobile dashboards or other parts. Example 2 The procedure of Example 1 was followed except that the material used was a sheet of a polysulfone and silicone block copolymer blend.

The sheet had a Tg of 180°C and a Ta of 300°C. The surface of the metal mesh forming plate that was to be in contact with the material was primed with a 5% solution of polysulfone in methylene chloride (as an adhesion promoter) and dried for 10 minutes at 275 °C before fixing the forming plate to the platen of the press. . The material was melted between forming plates in a press at 375°C and expanded at 340°C. Upon cooling and removal from the press, the expanded material was firmly bonded to both of the mesh mold plates. The expanded composite was approximately 11 nm thick and had regularly spaced rib sections as shown in FIG. This composite expandable material could be used as a structural member in furniture frames, automobile interior frames, and the like. Example 3 60% of the same high density polyethylene as used in Example 1
The method of Example 1 was followed using mil-thick sheets.

However, this plastic sheet was not treated with a silyl peroxide adhesion promoter. The mesh molded plates were heated to 180°C before the plastic sheets were inserted between them. The sheet was then expanded to approximately 5.4 times its original thickness. When it is then removed from the press and cooled to below 125° C., the expanded plastic is easily separated from the mesh plate and is lightweight, hard, has the shape of the expanded core 2' shown in FIG. Ribs were placed at regular intervals. Example 4 Melting index of 5, Tm of 165-175°C and about 170°C
The method of Example 3 was followed using a 60 mil thick sheet of polypropylene with a Ta of .

The polypropylene material was inserted between molded plates heated to 195°C and expanded at 170°C. The obtained material is
When cooled, it was easily separated from the mesh molded plate. That is 1
It had a size of 1 m1, a weight of 31 b/Yd2, and the shape of the expanded core portion 21 shown in FIG. This expanded material floated on the water and was able to evaporate and serve as sludge and water cooling tower packing. Example 5 Tm of about 130-170°C and T of about 160-180°C
The method of Example 3 was followed using as the stock a 60 mil thick sheet of thermoplastic polyether polyurethane having a.

The polyurethane material was inserted between molded plates heated to 175°C and expanded to four times its original thickness at about 160°C. The resulting expanded material was easily separated from the mesh molded plate. It is elastic and has an expanded core portion 2'' shown in FIG.
It had the shape of This intumescent material could be used as a cushion pad, lug cushion material or automotive pad material. Example 6 A perforated metal sheet as shown in Figure 6 is placed on a porous stainless steel metal plate, and the porous metal sheet is placed between the perforated metal sheet and the upper platen of the car half dress. and mechanically fixed it to the upper platen of the car halfless.

After heating the press platen and fixed metal sheet and metal plate to 160°C, the 120 mil thick sheet of high density polyethylene used in Example 1 was placed between the lower smooth surface platen of the press and the perforated metal sheet. It was then inserted into the press. The press was then closed to compress the plastic slightly and allow hot bonding between the plastic and the contact metal surfaces of the perforated metal sheet and the smooth side of the lower platen of the brace. The temperature of all metal surfaces was equalized to 135°C and the press was then opened to expand the plastic to approximately 250 mils. The plastic is then heated to about 60°C.
Upon cooling to , it easily separated from the two metal surfaces that served as mold surfaces. As shown in Figures 7 and 8,
The top of the resulting plastic expanded sheet was a positive copy of the perforated metal sheet, and the bottom of the plastic expanded sheet had a continuous smooth surface. The resulting expanded material was resistant to bending and was suitable for use as pallets. Example 7 An expanded sheet of plastic was prepared as in Example 6 from a mixture of 15% by weight of the ethylene-acrylic acid copolymer and 85% by weight of the high density polyethylene of Example 1.

This copolymer contained 83% by weight ethylene and 17% acrylic acid. The blend was prepared by hot rolling the ingredients on a two roll mill at total steam pressure (1921b/In2). The blend is approximately 12"
It had Ta of C. Add this blend to 120 mil thick 61
It was molded into a nX61n plate. Both contact surfaces of the platen were sprayed with a fluorocarbon polymer mold release agent before inserting the plate into the press. The board was processed with car halfless as in Example 6. The board was inserted into the press at 170℃,
14 Inflated at C. The plate was expanded to a new thickness of 11 nm at a rate of 1000 mils/15 seconds. The expansion plate was then cooled and it easily separated from the platen. This expansion plate had the shape shown in FIGS. 7 and 8. This cooled expanded core was heated to 185°C.
A mil-thick aluminum sheet was placed with slight pressure to effect wetting and upon cooling yielded a core of composite structure with an integrally bonded skin. Example 8 A 61n x 61n, 120 mil thick sheet was made from polyethylene (as used in Example 1) mixed with 2% by weight of gray pigment.

The sheet has a Tm of 130-140°C and a temperature of 135-140°C.
It had a Ta of ℃. The sheet was placed on the smooth surface of a car half-less nonporous platen that had been preheated to 170°C.

The plastic sheet was slightly compressed between platens to hot adhere it. The press was allowed to cool to 135° C. and then the press platens were opened a distance of 11n within 10 seconds. After 1 minute, the press platen was then cooled with water to 30°C and the expanded sheet of plastic was easily removed from the press platen.

Its dimensions were 6x6x11n. The plastic article had a uniform, smooth skin surface and had random plastic ribs in its expanded cross section as shown in Figures 14-16 of the accompanying drawings. The density of the expanded product was 0.247/CC. Further, the density of the sheet from which it was made was 0.967/CC. Example 9 An expanded product was prepared as in Example 8.

The plastic used was polycarbonate (General Electric Company's product name 18 Lexan 31 polymer).
A 1n x 61n x 120 mil sheet, which was dried in a vacuum oven at 110°C overnight to remove moisture. The resin had a Tg of about 150°C and a Ta of 320°C. The press was heated to 315°C before insertion of the plastic and expansion was carried out at 320°C. The plastic sheet was expanded to a thickness of 3/41 nm and then it was allowed to cool below 80°C. The cooled expanded product easily separates from the platen, and it
The expanded product had a random rib-like cross section and smooth surface characteristics as shown in Figure 6. The various polymeric resins used as expandable materials tend to absorb moisture, about 0.05 to 5.0% by weight, when exposed to the atmosphere.

This moisture is preferably removed from the plastic before it is placed in a hot press to avoid blistering or blistering in the heated plastic. Plastics that are more susceptible to this type of moisture absorption include polycarbonate resins, cellulose acetate resins, acrylonitrile-butadiene-styrene terpolymer resins, hydroxypropylcellulose resins, styrene-
They are acrylonitrile copolymer resin, phenoxy resin, polymethyl methacrylate resin and nylon resin. Example 10 An expanded product was prepared as in Example 8.

The plastic used was 6 inch x 6 of polymethyl methacrylate (trade name of Dupont! 1 Lucite 11 Polymer).
A 1n x 120 mil sheet was dried in a vacuum oven at 110°C overnight. The resin had a Tg of 105°C and a Ta of 160°C. The plastic sheet was expanded to a thickness of 3/410 at 200°C and then cooled to below 60°C. The cooled expanded product easily separates from the platen, and it
The product had a random rib-like cross section and smooth surface characteristics as shown in Figure 6. Example 11 An expanded product was prepared as in Example 8, except that the platen used had leather-like embossing on the surface and was used to create hot bonding with the plastic to be expanded. It was a 61n x 61n x 40 mil aluminum plate.

The aluminum plates were then secured to the car halfless platen with the embossed surface facing the inserted plastic material. It is then placed between embossed aluminum platens heated to 100°C with an RV of 0.7 in benzene and a T of about 60°C.
61 of polycaprolactone with Ta of m and 60 °C
An n x 61n x 100 mil sheet was placed. The press was then closed to compress the plastic slightly and create a hot bond with it. Next, set the temperature of the press to 6
Equilibrate at 5°C and place the plastic sheet at 1000°C.
It was expanded to a thickness of 1/21 nm at a rate of mil/8 seconds. 4
Plastics cooled below 0°C easily separated from the platen.

The expanded plastic sheet is shown in Figures 14-1 of the accompanying drawings.
It had a cross section of random rib-like tissue similar to the inflatable material 17 in Figure 6. However, the surface of the expanded polycaprolactone had a replica of the skin-like embossing on the contact surface of the aluminum platen. Example 12 The same operation as in Example 11 was carried out using an embossed aluminum platen.

The plastic material used was 61nx of nylon-6 resin with Tm of 212-225°C and Ta of 240°C.
It was a 61n x 120 mil sheet. A sheet of nylon 6 resin was placed in a press at 275°C, and then heated at 250°C.
It was expanded to a thickness of 7/81 nm at . The expanded product obtained is easily removed from the press cooled to below 40°C;
And it had an embossed surface and a random rib-like cross section. Example 13 6in x 6 of the polyethylene of Example 1 between two different surfaces
Expanding the 1n x 120 mil sheet, No. 17 of the attached drawing
The composite shown in the figure was prepared.

Upper mold 22 was the sheet of stretched metal mesh used as the molding surface in Example 1. The lower molding surface 23 is
It was a smooth-sided solid sheet of carbon steel 32 mil thick. Each of the molding surfaces 22 and 23 was removably attached to a car half dress. The two contact surfaces of the plastic sheet were treated with a silyl peroxide adhesion promoter as in Example 1. The plastic sheet was then expanded as in Example 1 to form an expanded composite having a thickness of 7/81 nm and the shape of the composite shown in FIG.
Ventilation of the voids 24 that appear at the top of the expandable material 21 during the expansion step in the method is via holes in the face of the plate 22 and between the perforated forming surface of the expandable metal mesh 22 and the upper platen of the car halfless. This was achieved through the interface between. The expanded plastic core rib portion 27 had an I-beam formation. When a sheet of high-density polyethylene plastic is expanded between molding surfaces 22 and 23 without being treated with an adhesion promoter, the expanded sheet can be easily separated from the molding surface, and this results in the shape shown in FIG. have.

As it is with the X, it is a rigid lightweight construction plastic core panel. Example 14 This example discloses the manufacture of an expanded product as shown in Figures 19-20 of the accompanying drawings.

A sheet of diamond-shaped metal mesh, as shown in Figure 1 of the accompanying drawings, was fixed face-to-face to a fired stainless steel porous plate. Two such assemblies are formed and one is attached to the face of the upper platen of the car halfless and the other is attached to the lower platen so that the porous plate in each case is in contact with the platen of the press. Adjacent. Then,
The surface of the mesh was positioned to be in contact with the material placed in the press. Also, the faces of the two metal mesh platens are arranged such that their diamond-shaped openings face each other at right angles, i.e., one of the stretched metal mesh surfaces is rotated through a 90 degree angle with respect to the other. Ta. 1
A 60 mil thick sheet of the polyethylene of Example 1 was placed between mesh molding surfaces heated to a temperature of 80°C.

The press was then closed to slightly compress the plastic sheet and create a hot bond between the plastic sheet and the metal mesh forming surface. The press was then opened to expand the plastic sheet to 5.4 times its original thickness when it turned to a clear shiny state. The voids obtained in the expanding sheet are
Ventilation was provided through holes in the metal mesh molding surface and through a porous metal plate attached to it. When the expanded sheet was then cooled, it easily separated from the platen. It is hard and lightweight, and it is
It had the shape shown in Figures 9-20. Example 15 Using the procedure of Example 14, a 60 mil thick sheet of polypropylene was placed in a press at 195°C and expanded at 170°C.

When the expanded sheet cooled, it easily separated from the molding surface and had the expanded product shape shown in Figures 19-20 of the accompanying drawings. Expanded plastic has a thickness of 11
n and had a weight of 31 b per art square. The temperature of the polypropylene resin used was 165-175°C.
Tm at 170°C, Ta. O. It had a density of 9O5 and a melting index of 5. Example 16 Using the procedure of Example 14, a 60 mil thick sheet of thermoplastic polyether polyurethane was placed in a press at 175°C;
It was then expanded to four times its original thickness at 200°C.

When the expanded sheet cooled, it easily separated from the molding surface and had the expanded product shape shown in Figures 19-20 of the accompanying drawings. Also, the expanded plastic sheet was resilient. Example 17 This example discloses the manufacture of an expanded product as shown in Figures 21-22 of the accompanying drawings.

A 1/81 nm thick perforated stainless steel plate with regularly spaced holes approximately 5/16 inches in diameter was prepared. The holes were arranged in aligned rows and columns in the plate, and each hole was spaced approximately 1/81n from the next adjacent hole. One of the perforated plates was then attached to each of the platens of the cover-place, such as the metal mesh plate 1 shown in Figures 2-4 of the accompanying drawings. The perforated plates were positioned on the faces of the top and bottom platens of the press such that the opening of each hole in the upper perforated plate was precisely aligned with the hole in the lower perforated metal plate. Next, 61n x 61n x 6 of the polyethylene of Example 1 was placed between the metal forming surfaces with holes heated to 180°C.
I put in a 0 mil sheet. The press was then closed to slightly compress the plastic sheet and create a hot bond between the plastic sheet and the contact surfaces of the perforated plate. The temperature of the platen and metal forming surface was equilibrated at 135° C. and the press was then opened to expand the plastic to a thickness of 3/41 nm. During the expansion process, the voids created in the expanding plastic were vented through holes in the metal plate and through the interface between the perforated plate and the platen of the press. When the expanded plastic was then cooled, it was easily separated from the perforated metal plate. The inflatable sheet had the product shape shown in Figures 21-22 of the accompanying drawings. The holes in the metal plate are replicated as holes in the intumescent sheet of resin, and the solid part of the plane of the apertured plate is replicated in the top and bottom of the inflatable product connected by the plastic web through the cross section of the inflatable sheet. Reproduced as a solid flange. Each hole in the top of the expanded plastic sheet is aligned with a hole in the bottom of the expanded sheet such that the expanded sheet provides a series of cells with circular openings at the top and bottom and a uniform wall between them. It was done.
Example 18 61n×61 foamed polyethylene by the method of the invention
An n×1/21n sheet was expanded.

The unexpanded foam sheet has a smooth surface and a
It had a density of 7/CC. Foam sheet is 0.96
density, melting index of 3, Tm of 130-140°C, 14
Made from polyethylene with Ta at 0°C. A smooth-sided steel platen was used to inflate the sheet in the car halfless. 2 sheets of foam plastic
It was inserted into the press at 05°C. The joint of the press was opened to slightly compress the plastic sheet and create a hot bond to it, and then the temperature of the joint was increased to 135°C.
Equilibrated at ℃. The press was then opened to expand the foam sheet to a thickness of 11 nm. During the expansion process, the expanding material was vented through its sides, such as material 17 shown in Figures 14-16 above. When cooled to about 40℃,
The expanded sheet easily separated from the platen. The surface of the expanding material is smooth and uniform, and the expanding material has a thickness of 0.3
It had a density of 7/CC. A cross section of the expanded foam sheet showed a random pattern of numerous foam cells that were larger in diameter than the cells in the original foam material. Example 19 This example illustrates the manufacture of an expanded product as shown in Figures 23-25 of the accompanying drawings.

The top and bottom surfaces of the 61n x 61n x 120 mil sheet of polyethylene of Example 1 were coated with 1/21n as temporary masking means as shown in Figures 23 and 24 of the accompanying drawings.
The width adhesive tape strips were placed 1/21n apart. The remaining strips of the exposed portion of the sheet were then applied with a fine double coat of a mixture of talc and clay in a water/methanol mixture as the primary masking means as shown in Figure 24 of the accompanying drawings. This was accomplished by first brushing a strip of exposed polymer portion with a slurry consisting of powdered talc and bentonite clay diluted to a brushable consistency with methanol and water.
While the applied slurry is still wet, mix it with about 1/2
It was ground with a spherical duster so that a fine coating of talc/clay with a thickness of 321 nm was deposited. The sheet was then dried in an oven at 100° C. for 10 minutes before the temporary masking means were removed. The sheet was then inserted between metal platens of a car halfless heated to 160°C. The press was then closed to compress the sheet slightly and to create a hot bond between the strips on both sides of the material from which the temporary masking means had been removed and the press platen facing. No hot adhesion occurred between the surface of the press platen and the strips on both sides of the material coated with the temporary masking means. Then press 100
The blank was expanded at 140° C. by opening to a thickness of 1000 mils at a speed of 0 mils/15 seconds. During the expansion stroke, the gaps or grooves 26 created between the ribs 25 were vented through the sides of the expanded material at their ends. Upon cooling to about 40° C., the expanded material easily separated from the press and had the shape of the expanded material shown in FIG. 25 of the accompanying drawings. The inflatable material had good stiffness in the longitudinal direction of the rib tissue.

EXAMPLE 20 The top and bottom surfaces of a 61n x 61n x 120 mil sheet of polyethylene of Example 1 were prepared using temporary masking means and primary masking means strips as described in Example 19, except that the strips on the top side of the sheet were Although parallel to each other, they were positioned at right angles to the strips on the bottom of the sheet, and the latter strips were also all parallel to each other.

The temporary masking means was then removed and the stock was expanded as in Example 19 to a thickness of 1000 mils. During the expansion process, the gaps or grooves created between the rib sections were vented through the sides of the expanding material and at its ends. Upon cooling to about 40°C, the expanded mass easily separated from the press. The inflatable ribs on the top surface of the inflatable material are all parallel to each other, and they are perpendicular to the inflatable ribs on the bottom surface of the inflatable material, with a continuous thin film or membrane of polymer between the two sets of ribs. It was hot. Each of the rib sections had an I-beam cross-sectional shape. The expanded sheet had higher stiffness in two planes than that made in Example 19. Example 21 This example discloses the manufacture of an expanded product as shown in Figures 26 and 27 of the accompanying drawings.

A 61n x 61n x 120 mil sheet of polyethylene from Example 1 had a polyethylene terephthalate (DuPont!
A 2 mil thick sheet of Mylar-1 polyester) was placed.
This top sheet served as the primary masking means to allow contact between the top exposed surface of the polyethylene sheet and the surface of the upper platen of the press when the polyethylene sheet was loaded face up into the press. The polyethylene sheet was then inserted face up into a 160° C. press, compressing the sheet slightly and creating hot adhesion between the surface of the lower platen of the press and the entire lower surface of the polyethylene sheet. The platen of the press was then closed to create a hot bond between the upper platen of the press and the portion of the top surface of the polyethylene sheet exposed through the hole in the film of the primary masking means.
At 160°C, no hot adhesion occurred between the surface of the upper platen of the press and the surface of the primary masking means, the polyethylene terephthalate film.

The material was then heated as in Example 19 at 140°C for 10
00 mil expansion. As shown in Figures 26 and 27 of the accompanying drawings, the resulting expandable material had a series of I-beam shaped sections 28 projecting from one side of the plastic sheet 29. The upper surface 30 of the I-beam section 28 was a section of polyethylene sheet adhesively bonded to the surface of the upper platen of the press through the holes in the primary masking means by hot adhesive during the expansion step of the method. . The elongated portion 28 was then formed when the platen of the press was opened with the top surface 30 attached. During the expansion process, the expansion section 3
The air gap between 0 and 0 was easily vented between the Mylar sheet and the platen and through the open side of the intumescent material. The primary masking means film was easily removed from the expanded mass and press, and it was reusable. Example 22 This example discloses the manufacture of multicellular containers as shown in Figures 28-29.

Low density polyethylene with Ta of 120°C (density 0.
92, melting index 2.0) 100 mil thick sheet (61n
×61n) was placed in a car half dress at 170°C.

The car half dress was as shown in Figure 2 of the accompanying drawings. The upper molded plate is a perforated aluminum plate, and the perforations have a staggered circular hole configuration as shown in FIG.
(between the outer edges).
The dimensions of the upper molded plate were 61n x 61n x 1/81n. The lower forming plate was the flat lower platen of the press. At a temperature of 160° C., the blank was compressed slightly to hot stick with the upper forming plate and the lower platen of the press, and then it was expanded to 20 times its original thickness at a rate of 15 mils/second.

When cooled to 35°C, the press was opened and the expanded paulownia was removed from the press.

The resulting expanded product had the shape shown in Figures 28-29 of the accompanying drawings. The base and top surfaces are approximately 2-5 mm thick
It was hot at the mill. The lip around the opening of each cell has a width of 2
/321n to 4/321n. During the expansion step in this method, the cells of the expanding material were vented through holes in the upper forming plate as described above. Dimension C for the open cells of the expanded multicellular container! When the batteries were inserted, they were held in place by the lip of the cell, even when the container was turned face down. The top shoulder of the battery fitted conveniently beneath the lip of the cell, and the top metal part of the battery protruded above such lip. Example 23 The procedure of Example 22 was carried out using a 65 mil thick sheet (61n x 61n) of ethylene-ethyl acrylate copolymer with a Ta of 110°C.

Place the sheet in a press at 150°C, and then press it at 140°C.
It was pulled to a height of 1001 nm at a temperature of . Expanded products are
It had the shape shown in Figures 28-29 of the accompanying drawings and was significantly more flexible than the multicellular container made in Example 22. Example 24 This example discloses the manufacture of an expanded product as shown in Figures 43-44 of the accompanying drawings.

1/8 with regularly spaced holes approximately 3/41n in diameter
An aluminum plate with holes measuring 1n x 61n x 61n was prepared. The holes were arranged in aligned rows and columns in the board as shown in Figures 40-41. Also, each hole was spaced approximately /In apart from the next adjacent hole. One of the perforated plates was then attached to each of the platens of the cover press so that the two perforated plates provided an overlapping pattern of holes in the plate as shown in Figure 42 of the accompanying drawings. Thus, the perforated plates were positioned on the faces of the top and bottom platens of the press such that the opening of each hole in the upper perforated plate overlapped with three of the holes in the lower perforated metal plate. Polyethylene (density 0.96, melting index 3, 130-140
6 with a Tm of about 135-140°C)
A 1n x 61n x 60 mil sheet was inserted. The plastic sheet is then slightly compressed and
The press was closed to create a hot bond between the plastic sheet and the contact surfaces of the perforated plate as shown. The temperature of the platen and metal forming surface was equilibrated at 140° C. and the press was then opened to expand the plastic to a thickness of 3/41 nm. During the expansion process, the voids created in the expanding plastic were vented through holes in the metal plate and through the interface between the perforated plate and the platen of the press.
The expanded plastic was then allowed to cool and was easily separated from the perforated metal plate. The inflatable sheet had the product shape shown in Figures 43-44 of the accompanying drawings. The perforated portions of the metal plate are replicated as open cells (77 and 78 in Figures 43-44) in the expanded sheet of resin, and the solid portions of the perforated plate surfaces are on the top and bottom surfaces of the expanded product and It was reproduced as a solid flange connected by a plastic web through the cross section of the sheet. All cells had uniform volume and height. The panel was hard. Example 25 This example illustrates the use of negative mold hole means to produce an expanded product having the shape shown in Figures 43-44.

A series of 3/41n holes were drilled into a 10 mil thick aluminum sheet to form a perforated sheet having the form of a formed plate shown in Figures 40-41.

The 3/41n holes were arranged in alternating rows and columns as shown in FIG. 40, and they were spaced approximately 3/161n apart from the next adjacent hole.

This perforated aluminum sheet was replaced with a 65 mil thick sheet of high impact styrene with Ta at 180°C (61n x 6
1n). White clay (-200 mesh)
75% by weight, toluene 5% by weight and ethyl alcohol 2
A release paint made from 0 wt. I made it. The polystyrene plate thus treated was then dried in an oven at 75° C. for 10 minutes and it was allowed to cool. In the same manner, the same pattern of release paint circular plates was applied to the other side of the resin plate. Applying a circular plate pattern to two opposite sides of a resin plate so that when the plate is laid flat on one side, the circular plate pattern on each of the two sides of the plate It was made to overlap vertically with three of the circular plates on the other side. This overlap pattern was similar to that provided by the two molded plates in Figure 42 of the accompanying drawings. The dry plate was then inserted between the upper and lower aluminum molded plates, which were fixed to the upper and lower platens of the car halfless, respectively.

Each of these two molded plates has a series of small vent holes drilled through the plate (#60 drill, 1/21n on center).
) is formed. The vent holes are positioned in the molded plate and made of polystyrene so that at least one vent hole is adjacent to each of the circular plates of release paint on each side of the plate at the interface between the plate and the two molded plates. The plates were positioned between the molded plates. The resin plate was placed in the press with the platen and mold plate at a temperature of 210°C, and the plate was expanded to an expansion height of 500 mils at 200°C at a rate of about 15 mils/second. During the expansion step in this method, the voids or cells with reduced pressure are
and 44 in the same manner as formed on the expanded material 74 shown in FIGS.

These cells adjacent to the release paint were vented through vent holes in the forming plate during the expansion process. The expandable material was rigid and had the shape of the expandable material shown in Figures 43-44 of the accompanying drawings. The cells in the expanded material had openings of substantially the same diameter as those in the release paint disc. After the expansion process, when the material cooled, the release paint adhered to the walls and base of the cells of the expanded material. Paint&ζ could be removed or left on the material depending on the intended end use. Example 26 This example discloses the manufacture of an expanded product as shown in Figures 30-31 of the accompanying drawings.

Two molded plates were used, these were shown in Figures 35-37.

The dimensions of their contact surfaces were 61n x 6in. The hexagonal holes were aligned and arranged in staggered rows and columns as shown in FIG. 35, with each hole spaced approximately 3/32 inches from the next adjacent hole. One of the perforated plates was then attached to each of the bratens of the car halfless so that the two plates provided the overlapping pattern shown in reproduction on the expanded blank of FIG. 30. Then,
A 61n x 61n x 60 mil sheet of polyethylene from Example 1 was placed between perforated metal forming surfaces heated to 180°C. The press was then closed to slightly compress the plastic sheet and create a hot bond between the plastic sheet and the contact surfaces of the perforated plate. The temperature of the platen and metal forming surface was allowed to equilibrate at 145° C. and the press was then opened to expand the plastic to a thickness of 0.7201 nm. During the expansion process, the voids created in the expanding plastic are filled with holes, vents 59, grooves 59A and U as previously described.
Ventilation was provided through the open walls of the shaped frame 56. When the expanded plastic was then cooled, it was easily separated from the perforated metal plate. The expansion sheet is shown in the figures 30 to 30 of the attached drawings.
The product had the shape shown in Figure 31. The perforated parts of the metal plate are replicated as open cells (42 and 43 in Figure 30) in the expanded sheet of resin, and the solid parts of the faces of the perforated plate are on the top and bottom surfaces of the expanded product and the expanded sheet It was reproduced as a solid flange connected by a plastic web through a cross section. All cells had uniform volume and height. The panels were rigid and useful as disposable shipping pallets. Examples 27-38 Using the molded plate shown in Figures 35-37, a 61n x 61n plate-shaped blank of a different thermoplastic material was expanded as in Example 26, and as shown in Figures 30-31 of the accompanying drawings. Expanded products were prepared as shown.

The materials had different initial thicknesses and they were expanded to different heights. Table 1 below lists (a) the polymeric material used in each plate; (b) the TaCC of each of the polymeric materials; and (c) the initial thickness of the plate when placed in the press. (Mill), (Yu Temperature of the platen and forming plate when the plate is placed in the press,
(e) Temperature of the platen, molded plate and polymeric plate at the beginning of the expansion step in this method; (f) Speed of separation of the molded plate during the expansion step (in mils/second) of the expanded material. Final thickness (in mils) (h) Notes on flexibility or stiffness and clarity or chromaticity of the resulting expanded material, etc.

The ABS resin plate used in Example 9 was coated with a rubber impact deformer of about 1
It contained 0% by weight.

The polyvinyl chloride plate used in Example 20 was annealed at 145° C. for 2 hours to relieve stress from it before being placed in the press.

During the expansion process, the material was expanded at a rate of about 15-20 mils/second.

Example 39 This example discloses the manufacture of an expanded product 64 as shown in Figures 38-39 of the accompanying drawings.

The molded plates used were those shown in Figures 35-3T. One of the perforated plates was attached to each of the platens of the car halfless so that the two plates provided the overlapping pattern shown in reproduction on the expanded material of FIG. 38. Then,
A 6 inch x 6 inch x 100 mil sheet of polyethylene from Example 1 was placed between perforated metal forming surfaces heated to 210°C.
The press was then closed to slightly compress the plastic sheet and create a hot bond between the plastic sheet and the contact surface of the perforated plate. The temperature of the platen and metal forming surface was equilibrated at 190° C. and the press was then opened to expand the plastic to a thickness of 11/4 inches. During the expansion process, the voids created in the expanding plastic were vented through the holes 58, air holes 59, grooves 59A and the open walls of the U-shaped frame 56 as described above. When the expanded plastic was then cooled, it was easily separated from the perforated metal plate. The inflatable sheet had the product shape shown in Figures 38-39 of the accompanying drawings. The perforated portion of the metal plate is copied into the expanded sheet of resin as open cells (6T and 68 in Figure 39), and the solid portion of the surface of the perforated plate is copied into the plastic web through the cross section of the expanded sheet. reproduced as solid flanges on the top and bottom surfaces of the expanded product connected together. All cells had uniform volume and height. The panel is rigid, and it
A hard skin layer of 1/61n melamine phenolic resin was useful as an interior wall panel core structure bonded by a contact adhesive. Examples 40-47 Blanks in the form of 61n x 61n plates of eight different thermoplastic materials were expanded to produce expanded articles as shown in Figures 32-33.

The materials had different initial thicknesses and they were expanded to different heights. Table 1 below lists (a) the polymeric material used in each plate; (b) the TaCC of each such polymeric material; and (c) the initial thickness of the plate when inserted into the press. (mil), (d)
(e) the temperature of the platen, upper mold plate, and polymer plate at the beginning of the expansion step in the process; (f) the initial temperature of the expanded material; Thickness (in mils), (g) notes on the flexibility or stiffness of the expanded material obtained and its transparency and chromaticity, etc. are described.

During the expansion process, the material was expanded at a rate of about 15-20 mils/second.

Example 48 An inflatable material 88 as shown in FIGS. 46-47 was manufactured.

61n x 61 of cellulose acetate with Ta at 170°C
One side of the nX125 mill sheet was provided with a series of V-shaped parallel grooves spaced 3/8 inches apart.

The groove is 50 mils deep and has 605 mm between its sides.
It had an angle of These grooves were sprinkled with powdered clay as a masking means. A second sheet of the same cellulose acetate, 61n x 61n x 40 mil, was placed on top of the V-shaped groove, as shown in Figure 45. The composite material was then placed in a car half dress at 220°C and it was expanded at 180°C at approximately 15 mil/sec to an expansion height of 1.241n. The expandable material had the shape shown in Figures 46-47. Although it was fairly rigid, the rib portion 92 was slightly flexible. Cells are approximately 11/3
It had a width of 21n. The expanded product is translucent;
and were useful as light scatterers or decorative wall partitions or panels. Example 49 Expanded product 88 was prepared as in Example 48.

The resin used was polymethyl methacrylate with Ta at 160°C. The top sheet of resin was 35 mils thick and the bottom sheet with V-grooves cut in it was 125 mils thick. Place the composite material in a press at 180°C and press it 7/8 at 160°C at a speed of 15 mils/sec.
It was expanded to an expansion height of 1n. Expanded products are from No. 46 to
It had the shape shown in Figure 47, was translucent, and was useful as a light scatterer or decorative wall partition or panel. Example 50 This example discloses the manufacture of an expanded product 97 as shown in Figures 50-52 of the accompanying drawings.

The molded plates used are molded plates 71 and 93 in FIG.
They were shown and arranged as follows. The expanding resin was a 75 mil thick sheet of acrylonitrile-butadiene-styrene terpolymer with a Ta of 180°C. Forming plate 71 was the same as in Example 24, and forming plate 93 was a 61n x 61n x 1/81n aluminum sheet.

The small holes 96 in the molded plate 93 had a diameter of 3/81n, the large holes 95 had a diameter of 1/21n, and the square holes had dimensions of 1/21n x 1/21n.

All of these holes in the forming plate 93 are located in each diagonal alignment of holes 11n apart from the center of the next adjacent hole, and the centers of all the holes are located in each vertical column and horizontal row of the next adjacent hole. aligned. As shown in Figure 48, the square holes were spaced 1/21n apart from each other in their vertical columns and 3/81n apart from each other in their horizontal rows. The large circular holes are 7/1 from each other and from the square holes in their vertical columns.
61n separated. The small circular holes were spaced 5/81n apart from each other and from the squares in their vertical columns. The two molded plates were secured to the upper and lower platens of the car half dress in the alignment shown in Figure 49 of the accompanying drawings.

The platen and molding plate were then heated to 220°C and the terpolymer material was inserted between the molding plates. A plate was closed over the blank, compressing it slightly, and when the temperature of the press equilibrated at 205°C, the blank was expanded at a rate of 15 mils/second to an expansion height of 875 mils. The intumescent material is cream colored, opaque, and hard, and it is similar to the intumescent material 97 shown in Figures 50-52 of the accompanying drawings.
It had the shape of

[Brief explanation of drawings]

FIG. 1 is a top view of a mesh metal sheet that can be used as a removable forming plate.

Claims (1)

[Claims] 1 A method in which a cross section of a material having Ta is expanded between a pair of molded plates to give the material the dimensions and shape of the expanded cross section, the expanded cross section being caused by expansion ribs of the material. a plurality of spaced apart cells, wherein when the shaped plate is brought into contact with the material, there is a pattern of at least some contact portions between the contact surface of the shaped plate and the contact surface of the material; one or more of the contact surfaces are designed such that the material is in a thermoformable state between the contact surfaces of the forming plate and the Ta is higher than or the molded plate and the material are brought into contact at their contact surfaces while the material is at a temperature higher than or equal to Ta to form a hot bond between the contact surfaces. and thus increasing the distance between the forming plates clamping the adhesively bonded materials while the materials are in a thermoformable state so that the expansion cross-section of the materials is expanded by the expansion ribs of the materials. causing an expansion of the cross-section of the material forming a plurality of spaced apart cells, where the cells include a section of partial vacuum, and the shape of each of the cells and the shape of the combination of cells is depending on the contact pattern between the contact surfaces of the forming plate and the material, which occurs during said expansion by balancing a low pressure level within the cell with a high ambient pressure level outside the material. traversing the material, including aerating the cells and cooling the expanded material to a temperature below the thermal deformation point of the material to maintain uniformity and integrity of cross-sectional dimensions; Surface expansion method.