Resin Finishing


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Resin Finishing

  1. 1. d   n  m   o   k  11 e   i   b   o  DENIMIST  2011   DNMSTDENIMDESINGFASHIONARTLIFE   DB DENIM BOOK D E N I M I S T
  2. 2. DB DENIM B O O K DENIMIST T U R K E Y  Since   decades   Denimist   has   developed   know-­‐how   in   denim   finishing   prior   to  garment   manufacturing   and   also   in   jeans   washing.   Our   customers   derive  benefit   from   this   experience.For   the   fabric   production   we   offer   finishing  chemicals   which   provide   the   demanded   fabric   properties   such   as   good  sewability,   stiffness,elasticity   and   handle.   The   other   field   of   our   activity   is   the  recommendation   of   laundring   Procedures   for   ready-­‐made   clothing   such   as  trousers,  jackets  or  skirts,  shirts.  In   doing   so   we   have   learned   that   many   errors   may   occur   in   this   complicated  production   process.  The   laundry,   the   last   step   in   the   sequence   of     producers,   is  faced   to   difficulties   which   are   caused   by   previous   inaccuracies.   Therefore,   a  good   cooperation   among   the   steps   of   jeans   manufacturing   is   required   to   avoid  problems.  Fabric  producer,  garment  manufacturer  and  laundries  have  to  work  together   to   obtain   the   desired   end   result.   By   means   of   our   contacts   on   both  sides  of  the  production  process  we  are  able  to  make  our  contribution.  The   technical   stuff   of   Denimist     is   always   ready   to   help   our   customers   with  eventual   problems   and   to   modify   production   procedures   according   to   the  respective   requirements.  Through   our   numerous   contacts   which   we   have   got  with  denim  producers,  garment  manufacturers  and  laundries  during  the  years  we  support  the  team  work  among  all  sections  of  the  jeans  chain  and  make  our  know-­‐how    available  to  all  of  the  parties  concerned    
  3. 3. DBDENIM B O O K RESIN  FINISHING   Resin  processes  have  become  more  popular  recently.  The  biggest  disadvantage   of   the   resin   processing   is   the   strength   loss   of   the   fabric.   There   are   3   main   reasons  for  this  strength  loss.            The  binds  which  are  formed  by  resin  break  the  binds  which  are  already  formed            on    the  fabric  and  giving  the  strength  of  the  fabric.            The  damage  of  cellulose  fibers  by  resin  which  has  a  very  low  pH          As  the  fabrics  treated  with  resin  have  a  stiff  handle  and  low  Slippin  gover              properties  the  tear    strength  of  the  fabric  falls  down.          
  4. 4. DBDENIM B O O K     After   the   resin   process   around   15-­‐40%   tear   strength   loss   is   observed   on   the   fabric.For   this   reason   some   standards   are   required.   E.g.   for   trousers   min   750   N   strength  for  warp  wise  and  600  N  strength  for  weft  wise  are  required.     Resin   Processes   can   be   done   either   on   the   washed   fabric   or   on   the   greige   fabric.If   it   is   to   be   done   on   the   greige   fabric,a   deairating   wetting   agent   like   Deniwet  SI  must  be  used  due  to  the  hydophility  problems.            Denires  CUBE    has  been  being  used  not  just  only  for  crinkles  and  whiskers  but              also  hand-­‐sanding  effect  as  the  hand  sanding  effects  of  the  fabric  will  be  brighter              than  those  which  are  not  treated  with            Denires  CUBE.(  Especially  if    Denires    U-­‐  TEAR      Denicoat  DERM  ,  Denires              TRITON    )  Denires  CUBE    treated  fabric  will  have  a  good  hand-­‐sanding  effect  as            well  as  a    good  sand    blasting  effect.          The  most  crucial  thing  for  the  resin  treated    fabrics  is  the  strength  loss    if    they              will    be  applied    handsanding  or  sand  blasting.          Like  resins,hand  sanding  and  sand  blasting  also  causes  strength  loss.For  this              reason,on  the  fabrics  which  will  be  done  handsanding  or    sand  blasting,along              with  Denires  CUBE  ,  Denires  U-­‐TEAR  ,  Denicoat  DERM    also    advised  to  be            used.  
  5. 5. DBDENIM B O O K RESIN  PROCESSES  FOR  INDIGO  DYED  GARMENTS      It  is  one  of  the  most  dangerous  process  in  a  washing  plant.Resin  processes  are            applied  to  a  garment  for  different  processes.These  are  ;          Permanent  3-­‐D            Grey  cast            Unwashed  appereance            Different  handles.      After  the  application  of  resin,the  temperature  is  increased  and  condensation  is        completed.    the  process  is  all  about  giving  a  new  form  to  a  garment  and  then  making  it        permanent.  In  that  sense  this  is  a  permanent  process  which  means  ther  is  no        chance  to  correct  the  faulty  garments.   MOST  COMMON  PROBLEMS   1.    Strength  loss  and  tearing     2.    Temporary  3-­‐D     3.    Lighter  shade  or  turning  of  the  cast  into  blue     4.    Failure  of  formaldehyte  test     5.    Differences  in  production     To  solve  these  problems,first  the  chemistry  of  the  process  must  be  understood.     As   mentioned   before,the   aim   of   the   process   is   to   give   a   new   format   to   the   fibre   and   keeping   it  permanently.This   happens   at   150   °C   and   meanwhile   due   to   the   catalayst  the  pH  falls  down.     Theorically  cellulosic  fiber  breaks  down  at  high  temperature  and  low  pH  which   is  not  required  practically.     For  this  reason  the  conditions  must  be  controlled  as  much  as  possible  and  some   auxilaries  must  be  used.  
  6. 6. DB DENIM B O O KAUXILARIS  AND  FACTORS    1.  TEMPERATURE  It  is  one  of  the  most  important  factors.The  temperature  must  be    increased  upto    150  °C  and  kept  stable  till  the  reaction  is  completed.  The  important  thing  is  the    temperature  of  the  surface  of  the  fabric  not  the  oven  temperature.    The  temperature  of  the  oven  will  be  adjusted  according  to  the      humidity  of  the    fabric,the  in-­‐oven  time  and  weaving  of  the  fabric.If    it  is  higher  than  160  °C  then    the  strength  loss  will  be  more  and  if  the      temperature  is  less  than  150  °C,then    permanency  problem  will    come  up.    2.  FABRIC  TYPE  The  strength  of  the  fabric  at  the  beginning  should  be  high  and  there  shouldn’t  be  any  alkali  on  the  fabric  as  it  will  disturb  the  pH.    3.  OVEN  To   avoid   the   failure   from   the   formaldehyte   and   differences   in   production,there  should  be  enough  ventilation  inside  of  the  oven  and  the  air  should  be  thrown  out  regularly.    4.  RESIN  TYPES  Resins   and   auxilaries   are   subject   after   all   the   above   conditions   have   been  ensured.  Generally  2  types  of  resins  are  being  used  in  the  market;    a.  Catalayst  built-­‐in  resins  as  Denires  CUBE  b.  Resins  without  catalayst  as    Denires  CUBE-­‐NC    Practically  the  catalayst  gives  extra  stiffness  to  the  fabric  but  that    doesn’t  mean    the  more  catalayst,the  better  permanancy  But  the  more  catalayst  means  the    Lower  pH  and  lower  strength.This  problem  won’t  be  faced  with  the  resins  that    Have    catalayts  in  as  the  adjustment  of  the  amount  of  the  catalayst  is  done    properly.    
  7. 7. DB DENIM B O O K5.  AUXILARIES  Denires    U-­‐TEAR        :  Decreases  the  strength  loss.Mixture  of  acrilates  and  gives    grey  cast.    Denires    U-­‐HRD          :    Harder  version  of  Denires  U-­‐TEAR  Denıres      TRITON    :    Wrinkle  Resistant  Agent  Denicoat    DERM        :    Polyethilene  emulsions  are  very  useful  to  avoid  the        strength      loss    and  to  increase  extra  strength  after  its  loss.But  it  must  be    remembered      that,if  it  is  used    at  the  beginning  of  the  process,it  decreases  the    unit  amount  of    resin  on  the  fabric  and    effects  the  permanancy  of  the  3-­‐D  ina        negative  way.    Denires    CUBE-­‐ML    :  Special  chemical  for  cross-­‐linking.It  increases  the  unit  amount    of  the  resin  on  the  fabric.In  some  cases  they  ensure  that  the  temperature  of    the    oven  drops  down  by  15-­‐25  °C  and  still  the  reaction  continues.This    is  helpful  with    the  garments  where  the  strength  loss  is  inevitable.    Denisoft    VIVID    :    Increases  the  brightness  of  the  fabric  after  resin    applications.effects    the  strength  positively  and  as  it  is  a  reactive    silicone,washing    permanancy  is  high.  
  8. 8. DB DENIM B O O K Denires CUBE Deni Res CUBEProduct  Line   Product  Group   Resin  Name  
  9. 9. DB DENIM B O O K SPRAYING    RESIN   150    gr      Denires  CUBE        50    gr      Denires  U-­‐TEAR     800    gr      Water     Drying  at  100  °C  for    15  min.     Curing  at  155  °C  for    15  min          If  a  brighter  look  is  required,  20-­‐50  gr/lt  Denisoft  VIVID  is  added  into    the  solution.          The  above  solution  is  made  1  liter  by  water.Then  it  is  applied  onto  the  fabric  by              spraying  and  the  crinkles  are  formed  and  baking  procedures    start.    
  10. 10. DB DENIM B O O KDIPPING  RESIN    Denires  CUBE            :    75      g/l    Denires  U-­‐TEAR    :    25      g/l    Drying  at  100  °C  for    15  min.                            Curing  at  155  °C  for    15  min  The  solution  is  prepared  according  to  the  above  ratios.The  trousers  are  dipped  into  the  solution.  After  keeping  them  in  the  solution  for  about  5-­‐15  min,they  are  taken   out   and   hung   on   the   hangers   for   about   10-­‐30   min.   to   ensure   that   the  excessive   amount   of   resin   will   flow   down.  Then   the   crinkles   are   formed   and   the  baking  is  done.  
  11. 11. DB DENIM B O O KWASHING  MACHINE  RESIN  Denires  CUBE            :  50  –  80    g/l    Denires  U-­‐TEAR    :  25  –  50    g/l    Deniwet  ZEN              :                      1      g/l    Drying  at  100  °C  for    15  min.                            Curing  at  155  °C  for    15  min  Liqour    :  1/4  or  1/10    Temperature  :  25  º  C    The   above   solution   is   prepared.1   trousers   is   weighed.  Then   water   is   taken   into  the   machine   and   the   chemical   solution   is   given   into   the   machine.   After   the  machine  runs  a  few  seconds,the  trousers  are  put  in  the  machine  and  run  about  5-­‐15  min.    Then   the   bath   is   dropped   and   the   machine   does   exctraction.(Crease   risk   at  extractor).After   the   exctraction   has   been   completedone   of   the   trousers   is  weighed   again   and   if   it   has   %50-­‐65   of   its   weight   of   resin   then   the   baking   process  is  applied.    
  12. 12. DBDENIM B O O K BAKING  PROCESS    •       After  the  permanent  crinkles  are  done  and  the  garments  are  clipsed,    •   They  are  put  in  the  oven  at    100  -­‐120  C  for  15-­‐  25  min.Then  the  garments  are              taken    out  of  the  oven,the  clipses  are  undone  and  put  in  back  in  the  oven    again        at  155-­‐160    °C  for  10-­‐20  min.In  this  point  2  parameters  are  crucial;        1.Oven  Temperature  :  The  temperature  inside  of  the  oven.      2.Fabric  Temperature:    The  temperature  reached  on  the  surface  of  the  fabric.      There  are  2  types  of  timing:        1.Baking  Time  :  The  duration  of  the  garments  staying  inside  of  the  ove        2.Reaction  Time  :  The  duration  after  the  temperature  of  the  garment  is  reached        up    to  required  temperature    •     For  example  in  an  conveyored  oven  where  the  entrance  into  the  oven    and  exit            out  of  the    oven  is  15  min.,the  reaction  time  would  be  around  5-­‐6  min.  •     The  same  thing  happens  in  the  chambered  ovens,too.For  this    reason,the            temperature  on  the  surface  of  the  garment  must  be    considered  and  the            calibration  of  the  oven  must  be  done  regularly.          Calibration  is  done  with  thermal  papers  and  they  are  placed  on  the  garment  as            follows:        Waist  Band  Area  :  As  this  area  is  thick  it  will  take  more  time  to  reach  to  the        desired    temperature.So  the  thermal  paper  must  be  placed  right  above  this  area.        Knee  Area  :  Thermal  paper  must  be  placed  right  in  the  middle  of  this  area        Leg  Area  :  Thermal  paper  must  be  placed  around  1  cm  above  the  leg  If  3        garment  having  those  thermal  papers  placed  on  them  are  placed  in  the          front,middle  and    back  of  the  oven,the  temperature  circulation  of  the  oven  can  be        measured    properly.    
  13. 13. DBDENIM B O O KDENIMIST  PRODUCTS  FOR  RESIN  FINISHING    Denires      CUBE             :    Reactive  Resin  With  Catalyst  Denires      CUBE-­‐  NF          :    Non  Formaldehyde    Resin  Without  Catalyst  Denires      CUBE-­‐ML          :    Self  –Cross  Linking    Denires      U-­‐TEAR               :    Soft    PU  &  Acrylate  Denires      U-­‐HRD               :    Hard  Acrylate  Denires      TRITON             :    Wrinkle  Resistant  Agent  Denires  CUBE-­‐NC              :    Self  Cross-­‐Linking  (  Catalyst  -­‐Free  )    Denifix      BOND-­‐DR          :    Special  Fixing-­‐agent  For  Getting  Dark  Cast  Indigo  Denicoat      1415                        :    Polyurethane  Emulsion  For  Soft  Handle  Denicoat      1500                        :    Polyurethane  Emulsion  For  Soft  Handle  Denicoat      CORE-­‐TR      :    Polyurethane  Emulsion  For  Soft  Handle  Denicoat      1507                         :    Polyurethane  Emulsion  For  Soft  Hand  And  Shinny  Effect  Denicoat      DERM                 :    Polyethylene  Emulsion    Deniart      TRINITY                :    Special  product  for    brillant  effect  Denisoft      VIVID-­‐U            :    Concentrated  Macro  Silicone  Emulsion  
  14. 14. DB DENIM B O O KRECIPE  OF  THE  DENIRES  CUBE  1.  STANDARD  RESIN  APLICATION              200    gr    Denires  CUBE    100    gr    Denires  U-­‐TEAR    700    gr    Water    Drying  at  100  °C  for    15  min.                            Curing  at  155  °C  for  15  min.  2.  RESIN  APPLICATION  fOR  HIGH    3  D          200    gr    Denires  CUBE  100    gr    Denires  U-­‐TEAR          20  gr    Denires  TRITON  680    gr    Water    Drying  at  100  °C  for    15  min.                            Curing  at  155  °C  for  15  min.  3.  RESIN  APPLICATIONS  FOR  HIGH    STRENGTH    200    gr    Denires  CUBE  100    gr    Denires  U-­‐TEAR  100    gr    Denires  DERM-­‐H  600     gr    Water    Drying  at  100  °C  for  15  min.    Curing  at  155  °C  for    15  min.    
  15. 15. DB DENIM B O O K4.  RESIN  APPLICATION  AT  LOW  TEMPERATURE  FOR  HIGH  STRENGTH  200    gr    Denires  CUBE  100    gr    Denirea  U-­‐TEAR      20    gr    Denires  TRITON      10    gr    Denires  CUBE-­‐ML  670    gr    Water    Drying  at  100  °C  for    15  min.    Curing  at  135  °C  for    15  min.    5.  RESIN  APPLICATION  FOR  ULTRA  GREY  CAST    200    gr    Denires  CUBE  100    gr    Denires  U-­‐TEAR  100    gr    Denires  BOND-­‐I  550    gr    Water    Drying  at  100  °C  for    15  min.  Curing  at  155  °C  for    15  min.    6.  RESIN  APPLICATIONS  FOR  EXTRA  BRIGHT  LOOK    200    gr    Denires  CUBE  150    gr    Denicoat  DERM-­‐H  100    gr    Denisoft  VIVID      500    gr    Water    Drying  at  100  °C  for    15  min.  Curing  at  155  °C  for    15  min.    
  16. 16. DB DENIM B O O KAPPLICATIONS  TO  INCREASE  THE  STRENGTH    7.  STANDARD  APPLICATIONS  TO  INCREASE  THE  STRENGTH    5      gr/lt          Denicoat  DERM  Temperature:  35  –  40  °C  Time  :  15    -­‐  20  min.    Drain    -­‐  exctract    -­‐  dry    Recipe  8  :For  extra  strength  increase    3    -­‐        5      gr/lt          Denires  U-­‐TEAR  3      -­‐      5      gr/lt          Denicoat  DERM  temperature:          35  –  40  °C  Time                        :        15    -­‐  20  min    Drain  –  Exctract    -­‐  Dry  9.  FOR  ALREADY  RESIN  APPLIED  WASHED  BUT  HAVING    STRENGTH  FAILURE      GARMENTS    Firstly    8  gr/lt              SODA  ASH  temperature  :  40-­‐  45  °C  Time                          :  5  min.    Drain    Rinsing  at  50  –  55  °C    for      2  min.  -­‐  drain    Secodly            5    gr/lt      Denires  U-­‐TEAR  5    gr/lt      Denicoat  DERM  temperature:        35  –  40  °C  Time                      :        10    -­‐  15  min.    Drain    -­‐  Extract    -­‐    Drying    
  17. 17. DB DENIM B O O KFABRIC  PROPERTIES  Changes  in  fabric  properties  are  related  to  the  number  of  crosslinks  imparted  to  the   fiber.   Improvements   in   wrinkle   recovery   and   DP   ratings,   and   reduction   in  residual   shrinkage   are   proportional   to   the   number   of   crosslinks.   Losses   in  strength   and   abrasion   resistance   are   also   related   to   the   number   of   crosslinks  and   to   the   degree   of   cellulose   damage   by   the   acid   catalyst.   The   number   of  cross-­‐links  is  influenced  by  the  add-­‐on,  (the  amount  of  reagent  deposited  on  the  fabric)   and   the   degree   of   curing   (percentage   of   the   amount   applied   that  become  actual  cross-­‐links).  The  degree  of  curing  is  influenced  by  the  chemical  structure  of  the  reagent,  the  type  of  catalyst,  the  ratio  of  catalyst  to  resin,  the  presence  of  buffers  and  the  time  and  temperature  of  cure.  A.  DURABLE  PRESS  PERFORMANCE  VERSUS  ADD-­‐ON  The  most  obvious  way  to  increase  DP  performance  is  to  add  more  finish  to  the  fabric.   The   relationships   between   fabric   performance   and   add-­‐on   of   DMDHEU  can   be   seen   in   figures   46.   Figure   46   shows   that   both   wet   and   dry   wrinkle  recovery   improvewith   increasing   concentration   of   reagent   in   the   bath.   Also  shown  is  the  relationship  between  DP  rating  (fabric  smoothness)  and  add-­‐on.  
  18. 18. DB DENIM B O O K1.  IMPORTANT  POINTS  There  is  a  sharp  increase  in  wrinkle  recovery  with  increasing  resin  level.  As  bath  concentration  approaches  7  %  DMDHEU  (15-­‐20  %  commercial  product  in  bath),wrinkle   recovery   and   DP   Rating   begin   to   levels-­‐off.  Above   this   level,   the  rate   of   improvement   is   less   rapid   and   only   modest   gains   are   obtained   with  massive  amountsof  resin.    Rela:onship  of  DP  Performance  versus  DMDHEU  Add-­‐on  
  19. 19. DB DENIM B O O KB.  EFFECTIVENESS  OF  DIFFERENT  CROSSLINKERS  How   many   cross-­‐links   does   it   take   to   obtain   optimum   performance?  Are   some  cross-­‐linkers  more  effective  than  others?   The  answer  to  these  questions  can  be  seen  in  figure  47.  Figure  47  is  a  composite  chart  where  wrinkle  recovery  is  plotted  against  the  concentration  (expressed  as  millimoles  of  reagent  per  100  grams  of  fabric)  of  a  number  of  different  reagents.  It  is  interesting  to  note  that  one  curve  fits  all  the  data  points.  Wrinkle  recover  levels-­‐off  at  2  to  2.5  millimoles  of  reagent.  While  DMDHEU  was  not  included  in  figure  16,  6  to  7%  weight  add-­‐on  calculates  to  be  2  to  2.5  millimoles  per  100  grams  of  fabric  and  so  it  too  follows  the  same  general  trends.   Crease  Recovery  versus  Resin  Concentra:on  
  20. 20. DBDENIM B O O KC.  TENSILE  TEAR  AND  ABRASION  RESISTANCE  Losses  in  tensile,  tear  and  abrasion  resistance  in  100%  cotton  are  directly  related  to   the   number   of   cross-­‐links,   The   relationship   between   abrasion  resistance,tensile  and  tear  strength  versus  resin  add-­‐on  is  seen  in  figure  48.  The  trends   established   in   these   curves   mirror   those   seen   in   figures   46   and   47,   except  these  are  going  the  opposite  direction.  The  steep  part  of  each  curve  appears  to  level  off  at  15  %  commercial  DMDHEU  (7  %  bath  solids)  in  the  bath.  Improved  DP  properties   also   tend   to   level   off   at   this   concentration.   Strength   and   abrasion  resistance  losses  will  amount  to  between  30  to  60  %  of  the  original  fabric  values   Physical  Proper:es  versus  Add-­‐On  
  21. 21. DB DENIM B O O KAbrasion  Resistance  
  22. 22. DB DENIM B O O KD.  Crease  Recovery  versus  Curing  Temperature  The  relationship  between  crease  recovery  and  temperature  of  cure  is  shown  in  figure   49.   The   temperature   required   to   obtain   cross-­‐linking   is   very   much   a  function  of  the  reactant  structure.  The  reactant  structures  included  in  figure  18  fall  into  two  groups,  easy  to  cure  and  hard  to  cure.   U/F  and  DMEU  fall  into  the  easy  to  cure  category.  Curing  starts  as  soon  as  the  fabric  is  dry.  These  reagents  would   not   be   suitable   for   delay   cure   where   one   needs   the   resin   to   remain  unreacted   until   after   the   garment   is   made   and   pressed.   DMDHEU   and  carbamates   fall   in   the   hard   to   cure   category   where   curing   temperatures   must  exceed  1300  C.  DMDHEU  has  been  successfully  used  in  delay  cure  applications.  The   fabric   can   be   handled   on   commercial   ranges   where   nearly   all   of   the   resin   is  still  uncured  after  dryin   Crease  Recovery  versus  Temperature  of  Cure  and  Resin  
  23. 23. DB DENIM B O O KE.  OTHER  FABRIC  PROPERTIES  1.  SHRINKAGE  Much  of  a  fabrics  residual  shrinkage  is  the  result  of  tensions  applied  to  the  fabric  during  wet  processing.   Some  woven  fabrics  will  shrink  both  in  width  and  length  during  preparation  and  dyeing.  These  must  be  pulled  out  to  maintain  width  and  yardage   yields.   These   stresses   add   to   residual   shrinkage.   Knit   goods   are  inherently   wrinkle   resistant;   however,   some   are   pulled   out   to   a   width   wider   than  the   fabrics   knitted   gauge   and   this   too   adds   to   residual   shrinkage.   Much   of   the  stress   induced   shrinkage   can   be   eliminated   by   mechanically   compacting   the  fabric.    Compacting  will  result  in  reduced  yardage  yields.  Crosslinking  also  reduces  fabric  shrinkage.   For   this   reason,   chemical   stabilization   of   cellulosic   fabric   has   real  economic   value.   Without   resin   finishes,   the   fabrics   described   here   will   have  excessively  high  residual  shrinkage.  Fortunately,  a  good  resin  finish  will  stabilize  the   fabric   and   reduce   the   residual   shrinkage   to   less   than   2%.   The   degree   of  stabilization   required   by   chemical   finishes   will   depend   on   the   fabrics   previous  history.   In   some   cases,   much   more   finish   is   applied   than   one   would   reasonably  consider   simply   to   keep   residual   shrinkage   within   the   required   tolerances.   In  these   cases,   reduced   shrinkage   is   the   real   reason   for   DP   finishes   rather   than  wrinkle  resistance  or  no-­‐iron  features.    2.  YELLOWING  Yellowing   of   DP   finished   fabrics   can   be   caused   by   a   number   of   condi:ons.   For  example,   excessive   curing   temperatures   and   /or   excessive   catalyst   will   scorch  cellulosic  fabrics.  Some  reactants  have  color  bodies  that  cause  yellowing.  Usually  nitrogenous   compounds   discolor   with   heat.   Buffers   are   oRen   added   to  commercial  finishes  to  combat  yellowing  problems.  
  24. 24. DB DENIM B O O K3.  CHLORINE  RESISTANCE  The  term  chlorine  resistance  encompasses  two  problems,  yellowing  of  fabric  by  the   bleach   and   tendering   (strength   loss).   Nitrogenous   finishes   will   react   with  hypochlorite  bleaches  to  form  a  reaction  product  (chloramides)  that  decomposes  with  heat.    These   chloramides   liberate   hydrochloric   acid   which   degrade   cellulose.   Fabric  develops   the   characteristic   scorched   look   and   the   fibers   become   very   weak.  Residual   -­‐NH   groups   are   responsible   for   the   formation   of   chloramides.   Resins  and   reactants   with   residual   -­‐NH   groups   and   cross-­‐links   that   hydrolyze   in  laundering   are   especially   prone   to   pick-­‐up   chlorine   from   a   bleach   bath.   Both  tendering   and   scorching   are   caused   by   the   breakdown   of   the   chloramide   with  heat  to  form  hydrochloric  acid.  The  reactions  can  be  written  as  follows:  
  25. 25. DB DENIM BOOKHead  Office   :   Kazimiye  Mah.  Karadeniz  Cad.  Kiliçoğlu  Al:n  Evler  No:  37/5/21    Çorlu  /  Tekirdağ  /  TURKEY   Ph:  90  282  673  62  40      Fax  :  90  282  673  59  75  Factory   :   Motor  Yerleri  Mevkii  E-­‐5  Uzeri  Ulaş  /  Corlu  /  Tekirdag  /  TURKEY    Pakistan   :   Plot  No:  2/C  Lane  No:  3  Itehad  Coom  Phase  –  VI  D.H.A  Karachi  /  PAKISTAN   Ph:  92-­‐21-­‐37820980  –  35348720    Cell  :  92-­‐300-­‐214430  Bangladesh   :   Road  36  ,  House  15,  F4,  Gulshan  2,  Dhaka  /BANGLADESH   Cell:  8801741393879