DESC:FIELD OF THE INVENTION
[0001] The present disclosure relates to a broad field of preparing caps. Specifically, the present invention relates to a method of manufacturing child-resistant caps (CRC) using continuous compression moulding technology, which consumes less energy, utilizes lower temperatures, and provides high specific density for the product. The method of preparing child-resistant caps is also cost-effective due to flexible maintenance and safety.

BACKGROUND OF THE INVENTION
[0002] Child-resistant caps (CRC) are a well-known safety solution tool to prevent children from potentially harmful injuries while using a wide variety of hazardous compounds in the cosmetic, personal care, household cleaning, and pharmaceutical areas. Child-resistant caps also meet compliance regulations for the cannabis, pharmaceutical, and nutraceutical industries. The World Health Organization (WHO) considers CRC one of the most effective tools for decreasing accidental injuries in children due to hazardous compounds. Child-resistant caps on pharmaceuticals and other related products have become a necessity today. CRCs are safe and life-saving for young children.
[0003] Compression moulding is a high-pressure moulding process wherein the polymer is melted, mixed, and homogenized inside a plasticizing unit. A device draws doses of polymer that have the exact same weight as the product and inserts them into the moulds. The pressure applied to each mould can be as high as 400 kg/cm2.
[0004] Continuous Compression Moulding (CCM), an automated, semicontinuous manufacturing process, has the capacity to take reinforced thermoformable input and produce highly shaped profiles or flat panels of effectively unlimited length. Operable by one person, the computer-controlled process yields products at speeds approaching those quoted for pultrusion — as high as 40 m/hr (131 ft/hr) for shaped profiles and up to 91 m/hr (300 ft/hr) for flat panels.
[0005] Unlike thermoplastic pultrusion, in which thermoplastic resin is injected into dry fibers at the die, CCM uses input materials akin to aerospace-grade epoxy prepregs — highly aligned, continuous fiber reinforcements pre-impregnated with high-end thermoplastics, including polyetheretherketone (PEEK), polyetherketoneketone (PEKK), polyetherimide (PEI) and polyphenylene sulfide (PPS). For non-aerospace applications, polypropylene (PP), polyethylene (PE), and other engineered plastics are common matrices. The resulting thermoplastic structures exhibit aerospace-quality consolidation. The void content is routinely less than 1 percent (verified by laminate micrographs), compared to the typical requirement of less than 2 % for autoclaved composites. Commercial products, to date, have used carbon or glass fiber (although they can be made with aramid or other fibers) and include highly loaded structural elements, such as the carbon fiber/polyetherimide (C/PEI) fixation rail assembly, with a part rejection rate of less than 0.1 %.
[0006] CCM hydraulic rotary presses are specially designed to produce thermoplastic products by means of compression. A continuous work cycle is carried out, during which the plastic material is fed by a plasticization unit, cut into suitably sized pellets, and inserted inside the cavities. Compression moulding is already a well-known technology worldwide. More than 45 % of plastic beverage caps are produced through compression.
[0007] US8316622B2 discloses a child-resistant assembly comprising an inner cap and an outer cap. The teeth on the outer cap engage with the inner cap when external pressure is applied to the outer cap. While engaged, the cap assembly is rotated counterclockwise to unfasten or unscrew the cap assembly from the bottle.
[0008] EP2479021B1 discloses a method of fabricating a thermoplastic laminate using continuous compression moulding technique. The method comprises the step of placing a laminate lay-up comprising multiple laminate plies in a recess within a tool and moving the tool through the moulding line to consolidate, and form said thermoplastic laminate part.
[0009] The child-resistant caps are manufactured widely using injection moulding technology. However, the method of preparing injection moulding technology has problems, such as the rate of production of the child-resistant cap being low, high-temperature requirement, thereby consuming high energy and less specific density product.
[0010] Thus, there exists an unmet need to provide a method of manufacturing child-resistant caps which provides a high rate of production, less energy consumption and high specific density for the product.

OBJECTS OF THE INVENTION
[0011] The present disclosure aims to provide a method of preparing a child-resistant cap (CRC) using continuous compression moulding technology.
[0012] It is a further object of the present disclosure to provide a method of preparing child-resistant caps (CRC) using continuous compression moulding technology, which consumes less energy, utilizes lower temperatures, and provides high specific density for the product.
[0013] It is a further object of the present disclosure to provide a method of preparing child-resistant caps (CRC) using continuous compression moulding technology, which is simple, convenient, and cost-effective.

SUMMARY OF THE INVENTION
[0014] Accordingly, in an aspect, the present disclosure provides a method of preparing child-resistant caps (CRC) using continuous compression moulding technology, which consumes less energy, utilizes lower temperatures, and provides high specific density for the product.
[0015] In an aspect, the present disclosure provides a method of preparing child-resistant caps by continuous compression moulding technique comprising the step of:
(a) loading raw materials into a hopper loader system with the help of an overhead centralized conveyor system;
(b) heating the raw materials from the hopper loader system in a heating zone to obtain a molten material;
(c) injecting the molten material into an injection phase to cut into different pellets and transferring the pellets into a cavity;
(d) compressing punches into the cavity with the pellets using hydraulic presses to obtain an inner cap or outer cap in a desired shape;
(e) ejecting the inner or outer cap continuously using strippers or sleeves and cooling the inner or outer cap using a cooling chamber;
(f) assembling the inner and outer cap from the cooling chamber to obtain a child-resistant cap; and
(g) wadding the child-resistant cap to obtain a final product;
wherein the cavity and the punches comprise cooling channels to cool the inner or outer cap at a cooling rate in a range of 10-15 °C.
[0016] In another aspect of the present disclosure, the raw material is pulled from a silo with the help of a vacuum system.
[0017] In another aspect of the present invention, the raw material is polypropylene (PP), polyethylene (PE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), or linear low-density polyethylene (LLDP) polymers or a combination thereof.
[0018] In another aspect of the present disclosure, optionally, the raw material is added with a coloring agent using a rotary mixer, motor, and cylinder in the hopper loader system.
[0019] In another aspect of the present disclosure, the heating step is carried out in at least three heating zones at a temperature in the range of 150-200 °C.
[0020] In another aspect of the present disclosure, in step (c), the pellets are transferred into the cavity using hydraulic presses.
[0021] In another aspect of the present disclosure, wherein a cooling rod in which water with a temperature of 10-15 ? will be flown through the channel to cool down the mould. When a pellet is dropped into the cavity, the beryllium copper core forms the inner profile of the cap. Next, the threaded part forms the inner cap thread profile, followed by using the bottom core part to form the bottom ring of the cap. Successively the interval sleeve releases/loosens the cap from the cavity to a certain distance which aids the stripping sleeve to finally eject the cap from the cavity.
[0022] In another aspect of the present disclosure, the method further comprises moving the inner & outer cap to the assembly and wadding machine through conveyors and hoppers to form the child-resistant caps.
[0023] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments.

BRIEF DESCRIPTION OF DRAWINGS OF THE INVENTION
[0024] The following drawings form part of the present specification and are included to illustrate aspects of the present disclosure further. The disclosure may be better understood by referencing the drawings in combination with the detailed description of the specific embodiments presented herein.
[0025] Figure 1 depicts the flow diagram of the method of preparing child-resistant cap by continuous compression moulding technique
[0026] Figure 2 depicts the flow diagram of the method of wadding of the CRC obtained from the present invention
[0027] Figure 3a-3g represents the cross-sectional view of the various parts of the continuous compression moulding technique.
[0028] Figures 4-6 represent the images of the child-resistant cap obtained from the method of the present invention.

DETAILED DESCRIPTION OF THE INVENTION
[0029] The following is a detailed description of the embodiments of the disclosure. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.
[0030] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies, and the definition of that term in the reference does not apply.
[0031] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.
[0032] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable. The numerical values presented in some embodiments of the invention may contain certain errors necessarily resulting from the standard deviation found in their respective testing measurements.
[0033] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0034] Unless the context requires otherwise, throughout the specification which follows, the word “comprise” and variations thereof, such as, “comprises” and “comprising”, are to be construed in an open, inclusive sense that is as “including, but not limited to.”
[0035] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illustrate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0036] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability.
[0037] The following description and the embodiments described therein are provided by way of illustration of an example, or examples, of particular embodiments of the principles and aspects of the present disclosure. These examples are provided for the purposes of explanation, and not limitation, of those principles and the disclosure.
[0038] It should also be appreciated that the present disclosure can be implemented in numerous ways, including as a system, a method, or a device. In this specification, these implementations, or any other form the invention may take, may be referred to as processes. In general, the order of the steps of the disclosed processes may be altered within the scope of the invention.
[0039] The headings and abstract of the invention provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.
[0040] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus, if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.
[0041] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
[0042] Push and turn CRC: A child-resistant container comprising: a container body; wherein the container body is a container with a closed base and an open top; the open top has a recessed lip leading to a pinched neck that is threaded; wherein the pinched neck leads to an inward rolled edge that is sealed by an aluminium foil to seal the inner cap, wherein the inner cap contains threads to screw the inner cap to the container body, and indentations stamped into the inner cap; an outer cap, wherein the outer cap rests over the inner cap and has an indentation or protrusions stamped into or attached to the outer cap that can fit in the indentations on the inner cap; wherein when pressure is applied to the outer cap and container body the indentations on the inner cap and outer cap provide enough friction to allow the outer cap and inner cap to move as one and screw the inner cap onto or off of the container body. The push and turn type CRC are disclosed in the US20060283831A1, ZA2020000309A, ZA2018003233 A, JP6322352 B2, US10414560 B1, IN202141040753 A, WO2008154575 A1, CN111166664 A, JP2018058652 A, US8141729 B2, US20190241330 A1, US20190315534 A1, US8316622, US4480759, US7111746 B2, US5579934 A, US20190382170 A1, US20060283831 A1, ZA2018003233 A, US8141729 B2, and US5579934A.
[0043] Squeeze and turn CRC: When a child of an age greater than six years or so, or an adult, desires to gain access to the contents of the container, the person disengages the child-resistant locking teeth and, by squeezing, from opposite sides of the collar, to bulge the collar outwardly in a direction normal to the direction of squeezing. This moves the locking teeth radially outwardly, disengaging them from the locking teeth, and the person may then rotate the cap and collar in a retrograde direction to remove it from the container neck. The squeeze and turn type CRC are disclosed in CN112224655A, US20200339320A1, GB2454566 A, US9950844 B2, US3993209, US7000789, and US6814259B1.
[0044] Squeeze and pull CRC: A correspondingly positioned rail inside protrusion and two correspondingly positioned rail outside protrusions have a width sufficiently greater than half the width of space such that these particular protrusions, even when squeezed and flexed, need to be in alignment with the corresponding cutouts to be removed. This requires two indicia, one on the outer member and the other on the inner member, that must be aligned to align the protrusions with the cutouts prior to squeezing, for opening. In this embodiment, the alignment would render the corresponding inside and outside protrusions releasable, and the squeezing would shift other protrusions to releasable positions, after which the cap can be pulled out. The squeeze and pull type CRCs are disclosed in WO2020236134A1 and WO2007106840A2.
[0045] Hidden switch/lock-up valve turn CRC: The invention discloses a childproof medicine-opening bottle, which comprises a container, an inner cap, and an outer cover body, wherein the container and the inner cap are connected and fixed by a thread-fitting connection. The inner cap is placed in the outer cover body and the container. The top center is pivotally connected with the hinge shaft fixed in the inner center of the outer cover body, and a longitudinal groove is provided on a side wall of the outer cover body. The slider in the outer cover body is connected to the groove. The lower-outer edge of the inner cap is covered with a rib to increase the friction between the slider and the inner cap, and the slider is operatively connected with the inclined slide rail. Both sides of the outer cover body are provided with inclined slide rails to rotate the cap. When the slider is placed at the top, the cap and the outer body do not contact each other. At this time, the cap does not rotate when the outer body is rotated. It will not be separated from the container to prevent children from opening the container when the slider is pushed to the bottom end, the slider contacts the rib on the inner cap, and the outer cover body and the bottle cap are locked. At this time, when the outer cover is rotated, the cap can be removed from the container. The hidden switch/lock-up valve turn-type CRCs are disclosed in CN107826447A.
[0046] The present disclosure relates to a method of manufacturing child-resistant caps (CRC) using continuous compression moulding technology, which consumes less energy, utilizes lower temperatures, and provides high specific density for the product.
[0047] In an embodiment of the present disclosure, Figures 1 and 2 depict the flow diagram of the method of manufacturing child-resistant caps.
[0048] In another embodiment, the present invention relates to a method of manufacturing child-resistant caps by continuous compression moulding technique comprising the step of:
(a) loading raw materials into a hopper loader system with the help of an overhead centralized conveyor system;
(b) heating the raw materials from the hopper loader system in a heating zone to obtain a molten material;
(c) injecting the molten material into an injection phase to cut into different pellets and transferring the pellets into a cavity;
(d) compressing punches into the cavity with the pellets using hydraulic presses to obtain an inner cap or outer cap in a desired shape;
(e) ejecting the inner or outer cap continuously using strippers or sleeves and cooling the inner or outer cap using a cooling chamber;
(f) assembling the inner and outer cap from the cooling chamber to obtain a child-resistant cap; and
(g) wadding the child-resistant cap to obtain a final product;
wherein the cavity and the punches comprise cooling channels to cool the inner or outer cap in a cooling rate in a range of 10-15 °C.
[0049] In an embodiment, the present invention relates to a method of manufacturing child-resistant caps by continuous compression moulding technology using raw materials such as polypropylene (PP), polyethylene (PE), low-density polyethylene (LDPE), high-density polyethylene (HDPE) or linear low-density polyethylene (LLDP) polymers or a combination thereof.
[0050] In another embodiment, the raw material for manufacturing the child-resistant cap is polypropylene (PP) or polyethylene (PE).
[0051] In another embodiment of the present disclosure, the method of manufacturing child-resistant caps by continuous compression moulding technique further comprises the addition of colorant in the hopper loader system.
[0052] In another embodiment of the present disclosure, the coloring pigment is used in the masterbatch. The coloring pigment is selected from but not limited to Lamite 78 (11078-K) and Promite 43 (11343-K).
[0053] In another embodiment of the present disclosure, the heating step is carried out in three to six heating zones at a temperature in the range of 150-200 °C. Preferably, in the range of 170-190 °C.
[0054] In an embodiment of the present disclosure, the 1 to 6 heating segments have temperatures 170 °C, 185 °C, 190 °C, 190 °C, 185 °C, and 180 °C.
[0055] In another embodiment of the present disclosure, the pellets from the injection phase are equally distributed across the cavity.
[0056] In another embodiment of the present disclosure, each molten material weighs about 3.85 gm for a 38 mm CRC outer cap. This weight can be changed in a certain range by changing the index of extrusion frequency.
[0057] In another embodiment of the present disclosure, the cavity is made of high-grade heat-treated stainless steel to attain longevity.
[0058] In another embodiment of the present disclosure, the cooling rate is in the range of 10-12 °C.
[0059] In another embodiment of the present disclosure, the speed of the compression process can be adjusted in the system by rotation frequency; for example, for the speed of 38 mm CRC outer cap, the frequency can be around 22-23 hz.
[0060] In another embodiment of the present disclosure, the continuous compression moulding machine has an individual hopper loader system, and with the help of the overhead centralized conveyor system, the raw materials are pulled from the silo with the help of a vacuum system as the raw material level gets low in the individual hoppers.
[0061] In another embodiment of the present disclosure, the continuous compression moulding machine has a removable dosage cum mixer in which colorant is added and has a control panel for the setting of percentage colorant loading.
[0062] In another embodiment of the present disclosure, the removable dosage cum mixer is assembled with a rotary mixer, motor, and cylinder.
[0063] In another embodiment of the present disclosure, the cooling rod in which water with a temperature of 10-15 ? is flown through the channel to cool down the mould. When a pellet is dropped into the cavity, the beryllium copper core forms the inner profile of the cap. Next, the thread part forms the inner cap thread profile followed by using the bottom core part to form the bottom ring of the cap. Successively, the interval sleeve releases/loosens the cap from the cavity to a certain distance which aids the stripping sleeve to finally eject the cap from the cavity.
[0064] In another embodiment of the present disclosure, the inner and outer caps from the cooling chamber are moved to the assembly and wadding machine through conveyors and hoppers. The caps are assembled with a liner/wad, which is dropped in the caps by an automatic wadding mechanism. These caps will again be checked for proper wadding through the vision system.
[0065] In another embodiment of the present disclosure, the caps approved by the vision system are packed in designated quantities into double-layered LDPE bags and finally packed in corrugated cartons. These boxes are duly labeled, and packed/taped boxes are transferred to Finished Goods (FG) stores. Before getting released, every batch must undergo testing as per USP.
[0066] In another embodiment of the present disclosure, the method of manufacturing child-resistant caps using CCM operates at a lower extrusion temperature, allowing the cap to be cooled in the mould more quickly, thus reducing the cycle time.
[0067] In another embodiment of the present disclosure, the production capacity of the method of manufacturing CRC using continuous compression moulding is higher than the production capacity of the injection mould.
[0068] In an embodiment of the present invention, figure 1 demonstrates the flow diagram of the method of the present invention. The method comprises producing the inner and outer caps using the continuous compression moulding technique and assembling the inner and outer caps to obtain the child-resistant cap.
[0069] In another embodiment of the present invention, figure 2 demonstrates the cooling step of CRCs obtained by the method of present invention. After cooling the CRC, the caps are inspected manually before packing.
[0070] In another embodiment of the present disclosure, figure 3 illustrates the various parts of the continuous compression machine for the manufacture of child resistant cap. Figure 3(a) depicts the water connection, i.e., a cooling rod in which water with a temperature of 10-12 ? will be flown through the channel to cool down the mould. Figure 3(b) depicts the cavity from which the outer surface of the cap is formed. The beryllium copper core is shown in Figure 3(c), from which the inner profile of the cap is formed. The thread part of the machine used for forming the inner cap thread profile is shown in figure 3(d) and the bottom core part used to form the bottom ring of the cap is shown in figure 3(e). Figure 3(f) depicts the interval sleeve portion used to release/loosen the cap from the core to a certain distance, and figure 3(g) depicts the stripping sleeve used to eject the cap from the cavity.
[0071] In another embodiment, the child-resistant caps obtained by the method of the present invention are push and turn CRC, squeeze and turn CRC, squeeze and pull CRC, and hidden switch/lock-up valve turn CRC.
[0072] Manufacture of Child-Resistant Cap
[0073] The child-resistant cap is produced as per the manufacturing process given below:
[0074] Each CCM has an individual hopper loader system, and with the help of the overhead centralized conveyor system, the raw materials are pulled from the silo with the help of a vacuum system as the raw material level gets low in the individual hoppers. On some machines where colorant (Masterbatch) is to be added, the machine has a removable dosage cum mixer (An assembly with a rotary mixer, motor, and a cylinder) in which colorant is added and has a control panel for the setting of percentage colorant loading. Taking the white masterbatch, for example, 25 kg raw material would be mixed with 300 gm masterbatch, and the percentage of masterbatch is 1.2 %. Certainly, it can be adjusted to the percentage; for example, in blue masterbatch, if we need dark blue, the percentage would be increased under the actual production.
[0075] Heating Phase
[0076] From the hopper, the material automatically goes into the melting zone of the CCM machine. This machine typically consists of 6 heating zones that heat the raw material, and with the help of a screw mechanism and shearing process, these materials are melted. On the control panel (the touch screen), there are a total of 6 heating zones. The temperature of the inlet is 175-185 °C, and the following are the middle-one, middle-two, middle-three, middle-four, and outlet temperatures. Middle-one, -three, and -four are around 185 °C. Only the middle-two is slightly higher than the other three zones, at around 190 °C. The last one is the outlet setting temperature, which is similar to the inlet, around 175-185 °C. The first step is heating when we run the machine. Once the countdown shows zero, it means the real-time temperature has reached the setting temperature, and then the machine can start.
[0077] Extrusion Phase
[0078] The raw material is fully melted in the machine screw, passed through the extruder, and extruded from the outlet. Further, these materials are cut by scrapers according to the target weight and transferred to the cavities. The weight of the cap is controlled by extrusion frequency, and the frequency is adjustable according to actual production. Generally, it is set at around 20-30 hz. If the grade of raw material is changed, the extrusion frequency will be adjusted accordingly. For example, with a 38 mm CRC outer cap, the extrusion frequency can be set at 28.3 hz.
[0079] Compression
[0080] As soon as the melt pellets are transferred to the cavities, hydraulic presses push the punches inside the cavities, as shown in Figure 3. The required tonnage is applied, and the molten material is formed into shapes, i.e., CRC. Cavity Cooling Phase (differentiation with traditional: Specially designed cavities & punches for CRC). Cavities and punches have cooling channels and a cooling rate of 10-12 °C. The speed of the compression process can be adjusted in the system by rotation frequency. For example, for the speed of 38 mm CRC outer cap, the frequency can be set at around 22-23 hz.
[0081] Ejection Phase
[0082] The caps are formed during the compression stage, as mentioned above. Since it is a continuous operation, the punches are pulled out, and with the help of strippers/sleeves, these caps are ejected.
[0083] Cap Inspection & Cooling Phase
[0084] All the caps are transferred to a vision system for 100 % inspection of defects, and only approved caps are transferred to the cooling chamber.
[0085] Assembly & Wadding Phase
[0086] The caps from the cooling chamber are moved to the assembly and wadding machine through conveyors and hoppers. Here the caps are assembled with a liner/wad, which is punched in the caps by an automatic wadding mechanism. These caps will again be checked for proper wadding through the vision system.
[0087] Final Product
[0088] Only approved caps will be packed in designated quantities into double-layered LDPE bags and finally packed in corrugated cartons. These boxes are duly labeled, and packed/taped boxes are transferred to Finished Goods (FG) stores. Before getting released, every batch must undergo testing as per SOP.
[0089] The images of the child-resistant cap obtained from the method of the present invention are shown in Figures 4-6. As shown in Figure 4, the outer teeth (10) of the outer cap lock the inner cap. Figure 5 depicts the outer and inner caps manufactured separately in the CCM machine. At a time, only one type of cap can be manufactured. So, two CCM machines, each for a type, will be used to manufacture the components simultaneously. After the manufacturing, both the caps will be transported using two separate conveyor lines to an assembly machine where a CRC cap will be assembled consisting of an inner cap, an outer cap, and a wad (used to maintain a seal with container). Figure 6 depicts the CRC cap consisting of an inner cap and an outer cap.

ADVANTAGES OF THE PRESENT INVENTION
[0090] Typically, the manufacturing of Child-Resistant Caps (CRC) utilizes the traditional method of Injection Moulding (IM) process. The significant advantages of CCM over the IM process are listed below:
[0091] Shorter cycle time: The method of the present invention operates at a lower temperature than injection moulding, around 10-20 °C less than the IM process. The lower extrusion temperature allows the cap to be cooled in the mould more quickly, thus reducing the cycle time.
[0092] Less energy consumption: The method of the present invention operates with lower extrusion temperatures, i.e., less energy is needed to bring the plastic to the extrusion temperature, and since the plastic is of a lesser temperature, less energy is required to cool it. Overall energy savings per cap produced can be as high as 30 %.
[0093] No gate marks: This is a significant & prominent advantage of the method of present invention over the IM process. The CRC caps made using the CCM process will not have gate marks on the components (since the material is equally distributed across the cavity rather than below the 1mm diameter gate, it will yield a high specific density for the product (CRC). Usually, gates in injection moulding will have defects like high gates, stringing, blow holes, etc. These are eliminated in the CRC produced through the CCM process.
[0094] Easy and flexible maintenance: Moulds made for the IM process have higher costs (100 % and above). The maintenance of moulds, especially the hot runner systems, are complicated; a highly-skilled workforce and expenses are involved.
[0095] Special mould: For CCM, special moulds like cavities and punches for producing CRC are made out of high-grade heat-treated stainless steel to attain more longevity than the moulds involved in the IM process
[0096] The method of manufacturing the CRC using the continuous compression moulding technique of the present invention is simpler than injection moulding.
[0097] The method of manufacturing the CRC using the continuous compression moulding technique of the present invention has more production capacity than injection moulding.
[0098] The method of manufacturing the CRC using the continuous compression moulding technique of the present invention involves lower tooling costs and maintenance cost.
[0099] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the disclosure is determined by the claims that follow. The disclosure is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.
,CLAIMS:1. A method of preparing child-resistant caps by continuous compression moulding technique comprising the steps of:
(a) loading raw materials into a hopper loader system with the help of an overhead centralized conveyor system;
(b) heating the raw materials from the hopper loader system in a heating zone to obtain a molten material;
(c) injecting the molten material into an injection phase to cut into different pellets and transferring the pellets into a cavity;
(d) compressing punches into the cavity with the pellets using hydraulic presses to obtain an inner cap or outer cap in a desired shape;
(e) ejecting the inner or outer cap continuously using strippers or sleeves and cooling the inner or outer cap using a cooling chamber;
(f) assembling the inner and outer cap from the cooling chamber to obtain a child-resistant cap; and
(g) wadding the child-resistant cap to obtain a final product;
wherein the cavity and the punches comprises cooling channels to cool the inner or outer cap in a cooling rate in a range of 10-15 °C.

2. The method as claimed in claim 1, wherein the raw material is pulled from a silo with the help of a vacuum system.

3. The method as claimed in claim 1, wherein the raw material is polypropylene (PP), polyethylene (PE), low-density polyethylene (LDPE), high-density polyethylene (HDPE) or linear low-density polyethylene (LLDP) polymers or combination thereof.

4. The method as claimed in claim 1, further comprises optionally the raw material is added with a coloring agent using rotary mixer, motor, and a cylinder in the hopper loader system.
5. The method as claimed in claim 4, wherein the coloring agent is Lamite 78 (11078-K) and Promite 43 (11343-K).

6. The method as claimed in claim 1, wherein the heating step is carried out in at least three heating zones at a temperature in the range of 150-200 °C.

7. The method as claimed in claim 1, wherein in step (c) the pellets are transferred into the cavity using hydraulic presses.

8. The method as claimed in claim 1, wherein during compressing the beryllium copper core forms the inner profile of the cap and the thread part forms the inner cap thread profile followed by using the bottom core part to form the bottom ring of the cap.

9. The method as claimed in claim 1, wherein the assembling and wadding are carried out through a wadding machine, conveyors and hoppers to form the child resistant caps.

10. The method as claimed in claim 1, wherein the child-resistant cap is push and turn CRC, squeeze and turn CRC, squeeze and pull CRC and hidden switch/lock-up valve turn CRC.