CROSS MEFEM :I TO ELATEP A FIJC:ATK>NS

[00OIJ TMs application elate the enefit of priority aader 35 IJ,S,C> § 1190) to United States Patent Application No. 13/410,503, filed February 3, 2012, l¾e d sclosro set forth the referenced application are ihcwpotated herek by reference an .its entirety.

B ACKGROU D O THE !f ENTI

[0002] The present I vention relates generally to methods and apparatuses for perfeimia an infrared treatment,, arid more particularly, to methods and apparatuses for performing an rrsif ared treatment en e^mded lastic and eiastoinerie products in an infrared oven.

[0003] It is known in the prior art to beat plastic or elastometie product that conies out of the extruder to ctoss-link tlte plastic or ekstomeric product to obtain a desired effect thai, changes the capabilities or properties of the product (e.g„ increases the strength, of the product, changes the product to solid, etc,). Furthermore, it is kijo n to perform this heating of plastic o elas omeric product nsmg infrared radiation and to use a wavelength of the radiatiori that penetrates inside the wai f of the product in sneb a way that the heating takes place at the same time in all the depths of the product

[0004] One prior art method is disclosed in patent prib!ication G 2283 489. Ϊ» this patent publication, the material is cross-linked by using infrared radiation ia suc a way that the temperature obtained, by the radiation corresponds to the wavelength demanded by the cross-linkage reaction.

[O005] A similar prior art method is presented in: the patent publication Fl 109706.. According to this method, arr dditional m ter l or additive that is used for modifying eithe ph sfcaily or chemically the properties of tb& .plastic material is decomposed utilising infrared radiation, wherein the wavelength is selected so that the radiation penetrates through the plastic material itself as efficiently as possible., but i also _: absorbed by the additional material, thereby healing .and decomposing d>© additional material.

[0006] The greatest disadvantage of the prior art methods is that the infrared radlatiott inevitably consists of a distribution of different wavelengths. It is also inevitable that a pari of thi wavelength distribution follows approximately part of the curve of Gauss, and the wavelength distribution has rays of long wavelengths that do not penetrate Into the material. Rather, the long wavelengths get absorbed by the surface of the product, causing Inconvenient overheating of the product, Overheating cause the surface of the product to become oxidized or to reae! In some other unwanted way.

[0007] Attempts have been made to solve this problem. For example, U.S. Patent Mo.

106,76! (¾e '761 patenf ^f ) addresses these issues by eliminating the irrfrared rays that correspond to absorption, peaks of the material to be heated in order to minimize overheating of a surface of the material The '761 patent, notes thai eliminating these rays may he accomplished by filtering out the unwanted rays. The filtering process disclosed in ths '761 parent is very difficult to uadertake because, when filtering out eet ak - ¾ve!¾«gths ₅ ^' the filter Itself gets overheated and Incomes a source of infrared energy that se¾ds the same filtered wavelength to the material, thus overheating the material

[0008] One solution that attempts to avoid the overheating /caused by filtering i cooling of the surface of the material duriag the in rared .treatment This ca be done, for example, by blowing cool gas,, like air, on. the material. The greatest disadvantage of this method is that the air also cools the infrared lamps and reduces the capacity of the lamps. Another disadvantage is. that dirt and other debris splashes fx m the material to the lamps and, t us, the lamps, get dirty, which again reduces the capacity of the lamps.

[0009] It is ry important for the irradiate material to be heated uniformly across an entire eross-seetiou of the material A method arid apparatus d¾r performing as imiared treatment, for xample., os plastic and elasiomeric products, that: overcomes all of the previous obstacles and thai inhfomi!y heats the product is therefore desired,

SUMMARY OF IBB INVENTION

[00.10] According to one aspect of the ptesept Inden ion, a method for performing an intared trea ment includes the steps of receiving m extruded plastic or elastomerie product and feeding the extruded plastic or elastonieric product to im. ove * including at least one lamp unit. The lamp unit ii¾¾|udes- lamp, a refieetiYe surface enclosing firs side of the lamp and .positione to direct radiation from the lam , and a glass disposed between a second side of the lamp and an extruded product, wherein the glass separates the lamp and the extruded product. The method further includes the step of creating cross-linking between the layers of the extruded product b directing, the radiation at the extruded product Still fiirther, the method includes the steps of directing a first gas _: Sow at a surface of the extruded product to cool the surface of the extruded product and directing a second . gas flow at the glass at an i ten ty,, direction, and temperature that prevents the glass from becoming an infrared source.

[0011 J According to another aspect of the present nvention,, the ovseo. includes a plurality of lam units eacn mcliidffig a plurality of lamps, a reflective surface enclosing a first side of each lamp and positioned to direct radiation fan. the lamp Into p allel .rays of radiation,: and a glass disposed between a second side of each, lamp and an extruded product, wherein the glass separates the l m and the extruded rod ct Two lam s are postponed afong a first axis: ami two tamps are positioned along a second axis that is perpendicular to the first axis.

[0012] According to a further aspect of the preset invention, the lansp is disposed; w&hin a housin with the lam being spaced from a first side of the housing and the glass being disposed adjac n a second side of the housing. In another aspect a third gas flo is provided through a channel in he onsing fer cooling components within the housing.

[0013] According to yet another aspect of the present invention a system for performing m infrared treatment on an extruded product ½elndes at least one lamp ami Ine!udmg a lamp and a reflective snriaee enclosing a fi s side of the l mp, wherein the reflective urface is positioned, to direct radiation from the lamp. The lam further includes a first gas flow directed at a surface of the extruded product for cooling: the extruded, product and a glass disposed betwee a second side of the lamp and the extruded product, wherein the glass separates the lamp and the extruded product- and ^' prevents the first gas flow from hitting the lamp. A second gas flow is directed at a side of the glass facin the extruded product for cooling the glass and preventing the glass from becoming: an infrared source.

[0014] A better ^' understanding of the objects, advantages, feamres, properties and. relationships of the invention will he obtained from the following detailed description and accompanying drawings which set forth m illustrative embodiment sad which are indicative of the various ways In which the principles of the In vention may be employed.

BRIEF PESCRI TXO OF THE DRAWINGS

[00:15] Fo -a better understanding of the invention, reference may he had to a preferred embodiment shown in the following: drawings in which: [0016] FIG. 1 is side levations! view of a first embodiment of an apparatus f x performing m infrared ireataieat on a plastic or elastonrerfc product or material :

[001?] flQ, 2 is a eross-secdoaal view takes generally along the Haes A~A of FIG. 1 and showing a single Infrared lan p nt; m<$.

[0018} FIG. 3 Is a magnified cross- sectional view of a portion of fee ia&ared lamp unit of FIG, 2 and depicting in greater detail one housing ooTftaising an irrirared lamp,,

DETAILED DESCRIPTION

[00 ! 9} Turning now to the iipres, wherein like reference uurnerals refer to like elements, there is illustrated aa apparatus or oven 100 for perforating an infrared treamieni oa a plastic or elastoruerie product or material. The apparatus performs the Infrared treatment without filterin of one or more wavelengths of the radiation.

[0020] Referring to FIG. 1, the apparatus in the ferai of an infrared oven or: system 100 is equipped idi sk infrared lamp units ^' 101. The infrared oven 100 is connected to an extruder (not shown) and extruded product 102 Is fed to the infrared oven. 100 by the extruder. The extruded product 102 may be fed from the extruder and redirected around a wheel 103 or other transfer mechanism at an angle of about 90 degrees,. The extruded product 102 aiay be any type of extruded, material m say shape. In one embodiment the extruded material may he a plastic or eiastomerlc tube. In other embodiments, the extruded product 102 is formed of polyethy lene aad or includes, one or more additional materials, such as additives o cross- linking -agents, as. known la the art. One nan-limiting example of an additional material is a cms sinkin peroxi de, for example an organic peroxide, which has to h heated to decompose and to create eross-dinlchig. Another non-Iirnidng example of aa additional material Is a chemical or physical, foaming agent that releases gas upon heating to form foaming within the material.

[CMS I J A first set 104 of infrared units 101 Includes ffrree infrared units 101 disposed adjacent one another n a first side 100 of the Infrared oven 100 and a second set 108 of infrared units 101 inelndes three infrared nnits 101 disposed adjacent one another on a. second side 110 of the infrared oven 100. A feeding apparatus 112 is disposed between th first and second sets 104, 1 8 of Infrared units lOL The feeding apparatus 112 inelndes any nnmber of pulleys, gears, wheels,. o.r other mechanisms tha aid in m.ovkg _: the extruded product 03 t rongh the infrared ov 100» The feeding apparatus 112 may additionally redirect the extruded product 102 ₅ for example, at an angle of about I SO degrees, As can be seen in FIG. 1, the extended product has a direetion of travel 1 I4> The feeding apparatus 112 is disposed between the sets X0 ,. 108 of inf¾r¾d units 101 suc that the first set 104 of Infrared, units 101 is disposed; before the feeding ap a atus 112 along the direction of travel 1.14 and the second: set 108 of infrared nnits 101 is disposed after the feeding apparatus 112 along the direction of travel 114, The positioning of th feeding apparatu 112 llo s the feeding appar ins 112 to provide the appropriate guidance to the extruded product throngh both sets .104, 108 of Infrared umts 101, Once Ore extruded product 102 exits the second set 108 of infrared units l OL th extruded prodne . may again fee ^■ redirected around a wheel 1.03; o other transfer mechanism, at an angle of about 90 degrees .

[0022] The orientation and nuxnber of infrared units 101 as shown in FIG. I may be varied, so long as th extruded product 102 Is properly treated, Le„ the extruded product 102 is tmlfbrraly Irradiated, For example, while f R1> I depicts six total infrared units 10 L any number of iiifrared units 101 may be trdlteed. Further, although three infrared units 101 are shown as being disposed prior to the feeding apparatu Π2 mi three infrared units 10! are sho mg as feeing disposed af¼r the feeding ppara s 1 12, an nu¾»¾er of infrared units 101 may bo placed before or after the feeding apparatus 112. in addition, while the sets 104 108 of Infrared units 1.01 are sho n as eing generally parallel, the sets 104, 108 may optionally be perpendicular, at any o her angle with, respect to one another, or along a single axis. Additionally, any number of wheels, gears, or other transferring aad½ redirecting mechanisms m y be utilized to transfer and/or redirect tbe extroied product 102 through the oven 100 arsd such transferring and/or redirecting: meehanisms may fee positioned at any point or points within the oven 1.00.

[00231 A single infrared unit 101 is depicted in detail in F JS. 2 and 3, wnereln each of the infrared units 101 may be similar in orientation and constraetion, Tbe -infrared unit 101 Includes: four Infrared lamps 120 formed In a. eircfe. Two of ^' the lamps 120 are disposed opposite, one another along a first a is 122 and the other two.- of the lamps 120 are disposed opposite one another alon a second, axis 124 with ^' t e firs axis 122 and the second axis 124 being perpendicular. Each of the lamps 120 Is therefore disposed at an angle of about 90 degrees abont a eenierpoinf 126 of the unit 101 with respect to ^' -an adjacent lamp 120.. Each lamp 120: is disposed within a separate ^' housing 130, Although four lamps 120 are depicted in FIG. 2, any nnmber of lamps ,120 that would uui&rrnl irradiate the extruded prodnct 102 mi irradiate the extruded product 102 from all sides may he utilized- One or more of the Infrared units 101 may be dliierent. in. orientation or construction from ike ot er infrared anils Ι0Ε For e¾ m ie _; the nnmfeer or location: of the lamps 120 may be 'varied.

[0024] When the lamps 120 are activated and the oven 100 is In operation,, each of the lamps 120 sends rays 140 of infrared radiation (onl some of the rays 1.40 are labelled) toward the product 102, In one enihodirnent., the rays 1 0: are parallel, which adds flexibility to the overall system: because tubes with different dimensions may be irradiated it ou the need to adjust the system. Some of the rays 140 penetrate throug a surface 142 of the product hit the additional material, that is vibrating, with. the same frequency, change into heat, arid caus a cross- linking reaction.. As ith the prior art, the wavelengths that are longer cannot penetrate the surface 142 of the extruded: product 102 and,, thus, the longer wavelengths are converted into heat and cause unfavourable heating of the surfac 142 of the extruded product 102, t Is therefore necessary to cool the extruded product 102 by directing a gas or air flow 143 onto the surface 143 of the extruded product 102. The gas flo 143 may he directed, in. this example, between the housing 130 and the surface 1 2 of the extruded product 102 from a side 144 of the imii 101 (FIG. 1). Heat-resistant glass 150 is installed between each of the lamps 12 aod the extruded product 102 to protect the lamps 120, :hi particular, the glass 15.0 prevents the gas flow 143 from hitting the infrared lamps 120 and prevents dirt or other debris from movi g from the extruded product 102 to the lanrps 12CK white still allowing cooling of the si -faee 142 of the extruded product 102. The gas flow 143, or any of the gas flows disclosed herein, may be air, nitrogen, or any other gas flow sufficient for cooling. If an air flow is utilised, the air flow may foe at ambient temperature and an intensity of an air Sow would depend upo production speeds and the amount and level of infrared radiation,

[0025] lire gas flow 1 3 can he directed t hit mainly the extruded product 1 2 and a second gas flow 152 may be arranged to impinge upon the sides of the glasses 150 lacing the extruded product 102 to cool the glasses 150 arid prevent the glasses 150 from entitling radiation that heats the surface 1 2 of the extruded, produc 102, It is possible to separately regulate ¾e gas flows 143, 152 (e.g., by independent s $o¾es) and, thus, it is possible to regulate eaeh of tfce gas flows 143, 152 {¾g, speed, temperarare) in e endently ¾¾m each, other, if necessary. It is also possible to have separate gas flows and regulation for each of the different glasses 15 wiihin a !amp unit JOI. While the gas flows 143, 152 are disclosed as b ing figm of gas or six, the gas flows 143 _» 1 2 may eaeh alternatively be one or more flows of aoy type or ty es; of gas suitable ibr copl!sg. an. extruded, material,

[0026] The direction of the gas flow 143 to the extruded product 102 may be from above downwards, fr m below upwards or some other direction, depending cm the orientation of the iuimt d unit 101 and the oveo I Oil The n ffaaf of gas flow 143 may be regulated, for the various infrared runts 101. For example., the amoiraf of gas flow 143 may be irrereased f om a first of the infrared units 101 to a. las of the infrared units in a process direction 60. as a temperature of the extruded product 102 generally increase in the process direction 160. Optionally, any other variation of gas flow 143 thai produces a desired product m be implemented, likewise, the gas flow{s) 152 that are used to cool the glasses I SO may be regulated differently in different infrared units 101 to correspond with the different needs of cooling of the diffbrent glasses ISO at different stages of the process.

[0027J Because some radiation f m the infrared lamps 120 ears get absorbed by the glasses 150, the glasses 150 earn sometimes become sources of infrared radiation and begin sending adiatioo toward the surface 142 of the extruded prodsct 102,. As noted above, the ga flows 143 and .152 are regulated k speed, tem emtnre,. direction, etc. so that they cool both the sur&ee of tbe product 102 and the glasses 150, respectively. Toe gas flows 143, 152 are regulated so that the surface 142 of the e¾tr«ded prod ct 102 does not react unfavourably (e.g., a burning smelt is ot created) and tbe glasses 150 do not emit infrared radiation. [0028] Eefemrig to ΒΘ, each of the housings 130 .mci fes a reflective surface 160 generally enclosing a first s de 162 of each, of the lamps 1.20. The reflective surfaces 160 may be coated with gold, bat may alternatively be coated with one or more ate reflective materials. E ch reflective swiaee 160 may have a shape thai directs all of the rays of infrared radiation 140 emitted from a respective lamp 120 along parallel paths within the housing 3 anc toward the extruded product 1 2. The parallel paths are also generally parallel o the xis 122 or 124 along which the spective: lamp 120 Is disposed. Any rays 140 of infrared radiation from opposite lam s 120 are also directed back m the direction from which they came by m opposing reflective s iaee 160.

f0@29! As best seen in FIG> ¾ a channel ISO is provided for guiding s third gas flow 182 (FIG. 3) ifcrottgh the knising 130. The third ga:s flow Ι Ζ may be utilized to cool and prevent damage to cabling inside the housing aad/or other sensitive components disposed within the hanging 130. As with, the gas flows 143, 1.52, the gas flow 1 g2 may include any type cr types of gas flow that suitably cool the components within the housing 130.

[0030] To enswre that the Infrared oven 100 of the present invention functions in the desired manner, a series of tests were conducted using the princi les of the invention, A plastic tube having an outside diameter of 16 mm and a wall thickness of 2 mm was extruded utilizing methods known in the prio art. The tube- was produced using, high density polyethylene with a high, molecular weight and before the extrusion,: 0.45 % of organle peroxide wa mixed wit the high density p¾lyethy!ehe. immediately alter extftiston of the tube, the tube was heated by the infrared radiation so that the heating length of the tube was 960 mm, the tube stayed in the oven for 6 seconds, t e irtfrared efficiency was 36 .kW, and the average wavelength of the infrared radiation, was 1.6 piioromcters. ^' f he temperature of the surface of the tube and in the middle of the wall iramediately after die extrusion was

[003 I J Four tests were c nducted and, in. each ease, the temperatures o a middl of the wall of the tube (Tl) and the surface of the tube (12) were measured alter tho Infrared heating and the results are listed the folJowmg chart:

Test. Tl ^" f effiperature T2 Ternperatere test 1, no insulating glass, no gas flow 2I0"C 3 UPC

Test 2. Insulating glass, no gas fiow 340°C

Test 3, uo insulating glass, gas flow !9S°C 200%:

Test 4.. Insulating glass, gas flow 210°C 2O0"C

[0032] It cm be seen from the results that the most, balanced result is achieved wit the ^' armngemeut of Test 4 where the gas flow cools both the surface of the tube arid the insulating g ass. This asxange en† corresponds wit the method , according to the present invention, la Test 3 , the gas flow also cooled the infrared source and, therefore, the measurement la the middle of the tube remained lower than in Test 4, [0033] The method, of using the oven 1 0 of the present invention to perform an Infrared treatment on an extruded plastic or elasionierle product allows .for cooling of the surface 142 of the extruded product 102 without decreasing the efficiency of the lamps 101. in partieirlar, the extruded product 102 I transported from an extruder to the oven 1.00 and enters a first side of the oven 1.00, 'The extruded product 102 then proceeds through a n mber of lamp units 101, each lamp unit 101 indikiiag at least one lamp 120, a reflective surface 16 enclosing a first side of the lamp 120 and positioned to direct rad tion from the lamp into parallel, ray 140 of radiation, and a glass 150 disposed between the second side of the lamp 120 and the extruded product 102. The glass 150 separates the lamp 120 and the extruded product 102, The method further includes the steps of directing the extruded product 102 throug he oven 100, directing the parallel rays of radiation at the extruded product 1:02 to create cross- linking between layers of the extruded product 102. A. first flow of cooling gas 1 3 may be directed at surface 1 2 of the extruded product 10 and a second flow of cooling gas. 152 may be directed at tic glass ISO for cooling the glass 150, The cooling ^' gas 152 is focassed at an ntensify, direction, and temperature that prevent the glass 159 from becoming an mftaied source and the glass 150, again, prevents the gas flows 143, 152 from hitting and cooling th : lamps 120,

[0034] While specific mbodiments of the invention have been describ d, in detail, it will be appreci ted by those skilled in the art that various modifications and alternatives to those detail could be developed in light of tic overall teachings of the disclosure. For example, different materials possessing similar characteristics may be used and the positioning of each of the layers with respect to one another may be changed. Accordingly, the particular arrangement disclosed is meant to be illustrative only and not limiting as to th scope of the Invention which Is to be given the .foi ^' breadth of the appended claims and any equivalents